application of the natrogen foam fluid sand washing technology

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水凝胶英语作文

水凝胶英语作文HydrogelHydrogel is a type of polymer material that has the ability to absorb and retain large amounts of water. It is commonly used in various applications including medical dressings, agriculture, personal care products, and even in the food industry.One of the key properties of hydrogel is its high water content, which makes it an excellent material for creating moist environments for wound healing. In the medical field, hydrogel dressings are often used for treating burns, ulcers, and other types of wounds. The moisture-retaining properties of hydrogel help to keep the wound bed hydrated, which promotes faster healing and reduces the risk of infection.In agriculture, hydrogel is used as a soil conditionerto improve water retention in dry or sandy soils. By adding hydrogel to the soil, farmers can reduce the frequency of irrigation and improve the overall health of their crops.This is particularly beneficial in regions with limited water resources or in areas that are prone to drought.In personal care products, hydrogel is commonly found in products such as contact lenses, facial masks, and moisturizing creams. Its ability to retain water makes it an ideal ingredient for products designed to hydrate and nourish the skin.In the food industry, hydrogel is used as a thickening agent and stabilizer in various food products. It can be found in a wide range of items including sauces, dressings, and bakery items. Its ability to absorb and retain water makes it useful for creating desired textures and improving the shelf life of food products.Overall, hydrogel is a versatile and useful material with a wide range of applications. Its unique properties make it an important component in various industries, contributing to advancements in healthcare, agriculture, personal care, and food technology.水凝胶水凝胶是一种聚合物材料，具有吸收和保持大量水分的能力。

12 METHANE FERMENTATION

12 METHANE FERMENTATIONMethane fermentation is an energysaving process used for more than a century in the treatment of sludge from MWW plants. Its scope of application has been gradually extended to include liquid effluents.Despite the high methane content of the gas produced, methane fermentation is nevertheless primarily a form of wastewater treatment; as such it must be designed to consume as little energy as possible without impairing the efficiency of the process, specifically in terms of mix ing, recirculation and heating systems.Other advantages of the process include low sludge production (see page 318), and reduced nutrient consumption.In most cases, methane fermentationdoes not result in wastewater characteristics suitable for discharge into the environment. In particular, the process has little effect on thenitrogenous pollution. An aerobic polishing treatment is generally necessary. Thetechniques that have been developed involvecontinuous processes and are of two majortypes:- suspended growth,- attached growth.Process ApplicationSuspendedgrowthCompletely-mixed see page 936 Excess sludgedigester unit Liquid manureDigester/settler Analift Concentrated wastewater(anaerobic contact)Sludge-blanket Anapulse Some dilute,digester easily degradablewastewatersAttached growth Ordered packing Anafiz Wastewaters of low- to(plastic media) medium-concentration withFluidized bed Anaflux low SS contentChap. 12: Methane fermentation 1. . GENERAL DESIGN1.1.ACIDIFICATIONAn acidification (hydrolysis) tank is sometimes required upstream from the fermentation reactor. It is used:- when retention time in the fermentation reactor is brief;- when the effluent has sulphate concen-trations of several grammes per litre, and depending on the COD value;- on certain substrates (such as glucose). This tank can also act to regulate pollutant flow. It is covered, in order to reduce influx of oxygen, and usually mixed. It is insulated to minimize heat losses and eliminate any need for heat input at the head of the facility.Depending on raw water characteristics, retention time varies between a few hours and 48 hours.Acidification is normally performed using suspended growth systems, although there is no fundamental reason why attached growth processes cannot be used.1.2.HEATINGProper temperature control is essential. A heating device is practically always necessary, even for hot effluents, if only during the low-rate start-up period. External heat exchangers, preferably with low sensitivity to suspended solids, are recommended.When retention times are brief, the raw effluent is often heated as it enters the tank. With long retention times (more than one week), heat is best applied to the contents of the r eactor itself, and concentric-tube exchangers must be used.When treatment is carried out on high-temperature effluents, a cooling system may be necessary.1.3. pHTo maintain a pH level of about 7 in the reactor, it is usually necessary to supplement the alkalinity of most industrial effluents. Alkalis are therefore added to the raw water, preferably in the form of lime (in the anaerobic contact process), to promote flocculation and sludge settling. In other processes requiring substantial quantities of alkali, caustic soda is preferable.1. General design1.4.SAFETY SYSTEMSThe reactor is equipped with the following safety systems:- pressure relief (air release valve); - negative-pressure relief (by injecting air or an inert gas through a vacuumbreaker);- fire and explosion safety (flame arrester) on gas lines;- safety device to prevent water condensation.1.5.GAS STORAGEThe methane produced by fermentation of IWW is generally used for heating purposes in the plant or on the site. It is stored in gas holders which compensate for production fluctuations and facilitate delivery to the burners. These gas holders often consist of flexible containers enclosed in structures, with a waste gas burner to complete the facility. If the gas produced constitutes only a small fraction of total fuel consumption, the gas holder may be replaced by a regulating system located inside the reactor.Chap. 12: Methane fermentation2. SUSPENDED GROWTHMethane fermentation of sludge, as it applies to liquid manures, is discussed in Chapter 18, page 932.2.1.ANALIFT(mixed digester + settling tank)This process, also known as the anaerobic contact process, involves a mixed reactor and a separate settling tank with a sludge recirculation system that can be regulated to maintain the highest possible sludge concentration in the reactor (Figure 421).Between the two main pieces of equipment, a degasification device is required to remove the occluded gas, which hinders settling, from the floc.2.1.1. Design• ReactorThe purpose of mixing is to keep the reaction medium homogeneous, in order to attenuate the effects of load fluctuations. The preferred mixing technique involves injecting gas through pipes made of corrosion-resistant material (see page 937). This mixing method has proved the most efficient and the easiest to implement. The absence of any moving mechanical parts inside the reactor ensures safety and reliability.The reactor can be made of concrete, steel, or plastic. Internal anti-corrosion2. Suspended growthprotection is often required. Insulation must be extremely effective so that temperature is kept constant at the desired level in the medium. Under particularly favourable climatic conditions, this requirement may be waived.• DegasificationThe sludge mixture emerging from the reactor passes through a degasifier which serves three purposes:- stilling (if required);- degasifying of the liquor;- flocculation of the sludge.Retention time in this unit must be at least 30 minutes. A variety of degasification methods are available. Covering requirements and the layout of the facility may point to the use of a vacuum degasifier. Slow mixing is also often used.• Settling tankThe settling tank can be viewed as a thickener, since the sludge is highly concentrated upon extraction. The unit is sized on the basis of the solids loading, entailing rising velocities of 0.05 to 0.2 m.h-1.The sludge recirculation rates implemented typically range from 50 to 150%.2.1.2. Applications and performanceThis process, which is relatively insensitive to load fluctuations, is suitable for concentrated effluents (distilleries, canning factories, chemical industries, paper and pulp industries), and for dilute effluents which involve a risk of mineral precipitation (sugar beet refineries).With the methane fermentation and settling functions handled in two separate units, independent access is available to each, for the following purposes:- transferring sludge from one tank to the other to facilitate maintenance and restart operations;- stripping H2S (a gas produced by sulphate reduction that tends to inhibit theChap. 12: Methane fermentationmethane fermentation process) and treating the gas elsewhere;- discharging the inorganic fraction of sludge after centrifuging.Applied COD loads depend on the type of effluent and the desired removal efficiency, and vary between 3 and 15 kg/m3.d.COD removal efficiency ranges from 65% (for a molasses refinery) to more than 90% (sugar beet refinery). BOD5 removal efficiency ranges from 80 to 95%.2.2. ANAPULSE (sludge blanket digester)This process is suitable for effluents that lead to the formation of "granulated" sludge (see page 318).2.2.1. Design• ReactorIn this type of upflow reactor, the raw water passes through a sludge blanket before flowing into a settling tank located in the same module, for removal of any suspended solids entrained from the sludge blanket. The blanket is homogenized by production of gas within the sludge.The raw water feed is pulsed to ensure even distribution of flow over the entire reactor cross-section. This arrangement enables the use of large-diameter feed pipes, thereby reducing the risk of clogging.The reactor can be made of concrete or steel, suitably protected. It is thermallyinsulated.2. Suspended growth• Settling tankThe sludge blanket normally has a filtering effect. Residual suspended solids are retained in the settling tank Two configurations are possible: - adjacent settling tank, offering a large surfacearea for gas release and allowing the construction of units of limited height (Figure 423);Figure 424. Armentières (Northern France) facility for the Sébastien Artois brewery. Capacity: 8 tonnes COD per day. Anapulse reactor for effluent methane fermentation.Chap. 12: Methane fermentation- top-mounted settling tank, not recommended for dilute effluents (Figure 425).In both cases, gas-lift pumps are used to recycle the settled sludge. The settling tank contains no moving mechanical parts.2.2.2. Applications and performanceThis process is applicable to dilute, easily degradable effluents from agricultural and food processing industries (breweries, starch plants, etc.). It is generally not suitable for concentrated effluents and/or those containing readily settleable SS (such as clay or calcium carbonate).Applied COD loads vary between 6 and 15 kg/m3.d, depending on effluent characteristics. Depending on the prior retention time, acidification treatment is often necessary.This technique has been suggested as a pretreatment for municipal wastewater in hot climates.3. Attached growth 3. ATTACHED GROWTH3.1.ANAFIZ(attached growth on organised support medium)In this process, the bacterial film grows on a fixed plastic medium, through which the water passes in upflow.3.1.1. DesignWater and gas circulate in cocurrent flow in the reactor (Figure 426), which is fed at the bottom. To ensure proper raw water distribution over the entire crosssection of the unit and thereby eliminate any risk of preferential paths, a sufficient upflow velocity must be maintained, which often entails recycling of treated water.The raw water feed system and the treated water recovery device at the top are also designed to ensure full utilization of the contact medium.The medium typically consists of two layers, through which the r aw water passes in succession:- a lower layer of organised support medium, in which bacteria colonize rather slowly but which shows little tendency to clog. A double colonization often occurs here, consisting of the attached biological slime as well as a sludge blanket which increases the quantity of avail-Chap. 12: Methane fermentationable biomass. Hydrolysis of the raw water SS can occur here;- an upper layer of random fill featuring a high specific surface, allowing rapid colonization and offering favourable conditions for methanogenesis (which, in this process, is the reaction requiring the most intimate contact between the substrate and the active biomass). The risk of clogging of this type of material is greatly diminished by the fact that the raw water has first passed through the lower hydrolysis zone and is already in the methanogenesis phase, during which little excess biomass is produced.When the raw water has undergone prior complete acidification (as is frequently the case with sugar refinery effluents), the ordered packing can be eliminated. Alter natively, ordered packing may be replaced by random fill if the effluent to be treated contains no suspended solids.In most cases, excess sludge is discharged with the treated effluent, and periodic gas injections may also be performed to create turbulence in the packing. Depending on the effluent quality required, additional clarification may be necessary.In addition, sludge is periodically extracted through the lower reactor zone.The reactor can be made of concrete, suitably protected steel, or plastic, with thermal insulation.3.1.2. Applications and performanceThe Anafiz process is suitable for relatively dilute effluents from agricultural and food processing industries such as dairies, distilleries, sugar refineries (if lime is not used in the process), sweets factories, etc.Depending on raw water composition, the COD load applied ranges from 8 to 15 kg /m3 A, with COD removal efficiencies of 70 to 80%, and BOD5 removal rates between 80 and 90%.Figure 427. Ahausen facility (Germany) for DAA. Capacity: 12 tonnes COD per day. Methane fermentation of distillery effluents in an Anafiz reactor.3. Attached growth3.2. ANAFLUX (attached growth on fluidized bed)In this reactor (Figure 428), the bacteria are attached to a granular medium that expands due to the upward flow of the liquid being treated; this improves substrate/culture contact, and maximizes the area available for film attachment per unit volume.This type of reactor allows the most concentrated growth of active bacterial colonies and can therefore accommodate the highest loadings.A special Biolite filter medium with NES of less than 0.5 mm was selected on the strength of the following characteristics:- porous structure with high specific surface, - low density, - resistance to attrition,- strictly controlled manufacturing conditions.3.2.1. DesignThe reactor can be made of either steel or plastic. Anti-corrosion protection and thermal insulation are often necessary.A rising velocity of 5 to 10 m.h-1 must be maintained to ensure fluidization of the medium; this generally entails raw water recycling. After the mixture is injected into the reactor, a three-phase separator is used to recover any entrained Biolite, which is then recycled with a pump. As bacteria gradually colonize in the medium, excessive density loss may occur as the medium is entrained out of the system. Detaching the excess biomass from a portion of the medium in a highChap. 12: Methane fermentationturbulence chamber constitutes a means of removing this excess matter with the treated water. An added clarification step may be necessary for removal of suspended solids 3.2.2. Applications and performanceThe high loads applied involve r elatively short retention times in the reactor, dictating a prior acidification step in most cases.The principal advantages of the process are:- no risk of clogging of the support medium, - rapid start-up,- compact treatment unit,- no risk of biomass entrainment,- accommodation of considerable flow variations, within the velocity range acceptable for fluidization.Depending on the raw water characteristics, the COD load can vary between 30 and 60 kg/m3.d with treatment efficiency ranging from 70 to 90%. The Anaflux process is suitable for effluents having COD values on the order of 2.5 g.l-1 or more, i.e., effluents from food processing industries (breweries, sugar refineries, canning factories, starch plants, distilleries, dairies, etc.), the paper industry (paper mills, evaporation condensates, etc.) and chemical or pharmaceutical plants.Figure 429. Anaflux pilot unit..4. System start-up and control procedures 4. SYSTEM START-UP AND CONTROL PROCEDURES4.1.START-UPAND SEEDINGSeeding is always required when a unit is started up, except in the case of MWW sludge and liquid manures.Special precautions must be taken when treating effluents from chemical plants, paper pulps, etc., and in general, whenever natural seeding of the raw water has been blocked (alkalinization, sharp temperature increase, high salinity). The quantity of seeding sludge must be as great as possible in order to reduce start-up time.Initially, the loading rate must be limited, and sludge losses will be relatively large (acclimatization). Given the low rate of microorganism synthesis (0.1-0.2 kg VS per kg of BOD5 removed), the choice of seeding m aterial is critical.The activity of the seeding sludge must be monitored, and the location of the sampling point is also important. To limit the quantities of sludge to be transported, sludge (except from attached growth systems) can be thickened by centrifuging or filtration (GDE, Superpressdeg). These operations must be monitored with respect to storage time, polymer dosage, etc.After a reactivation period of a few days (for temperature stabilization), the COD load applied should be approximately 0.1 kg/kg VS.d; it is then gradually increased to maintain a VFA/M alk. ratio of less than 0.2, and a pH close to 7.It is reasonable to expect to double the load every 10-20 days, depending on raw water characteristics and the process implemented.• Type of seeding sludgeThe following may be used:-acclimatized sludge, - digested MWW sludge, or - livestock refuse (cattle, pigs).The parameters used to monitor the seeding sludge selected are:- kg of COD removed per kg of VS per day,- m3 of gas per m3 of reactor capacity per day,- pH and operating temperature,- % VS.• Required sludge quantitiesAnalift 3-5 kg VS per m3 of reactorcapacity;Anapulse 30% of reactor capacity asgranulated sludge (start-up in afew months) or 10-20% ofreactor capacity (prolonged start-up period);Anafiz 3 kg VS per m3 of reactorcapacity;Anaflux < 10% of reactor volume.Chap. 12: Methane fermentation4.2.OPERATINGPARAMETERSDuring normal operation, the following parameters must be monitored- temperature: generally 35°C ± 2°,- VFA: normally < 500 mg.l-1 ,- VFA/M alk.: < 0.2,- pH: ˜ 7, - gas roduction: approximately 0.4 ± 0.05 in' per kg of COD removed,- % CO2 in the biogas (must remain constant).In most cases, if malfunctions occur, the load must be reduced; the parameters listed above should be checked more frequently and any deficiencies (nutrients, trace elements, toxic substances) remedied.。

Natural convection in water-saturated metal foam

Natural convection in water-saturated metal foamV.Kathare,J.H.Davidson *,F.A.KulackiDepartment of Mechanical Engineering,University of Minnesota,111Church Street,S.E.,Minneapolis,MN 55455,United StatesReceived 27August 2007;received in revised form 21November 2007Available online 7March 2008AbstractNatural convection in water-saturated copper foam is measured for 2.5Â10À4<Da <1.2Â10À5,10<Ra m <210,and 7.5Â105<Ra f <2.5Â108.Experiments are reported for foam with 92%porosity and 10and 20pores per inch.The primary ﬁnding is that the Nusselt numbers do not follow the published heat transfer correlations with Rayleigh number for a packed bed of spheres and are 27–42%less than that predicted by these correlations at the maximum Rayleigh numbers encountered for Da $10À5.A single heat transfercorrelation of Nusselt number is obtained in terms of Rayleigh and a modiﬁed Prandtl number equal to Pr m Da À1=2C À1f .In comparison to natural convection in a water layer,enhancement of heat transfer is primarily via conduction.Enhancement of the advective component of heat transfer is obtained only for Ra f $108and 1.2Â10À56Da 62.4Â10À5.Ó2008Elsevier Ltd.All rights reserved.Keywords:Natural convection;Metal foam;Porous media1.IntroductionThe use of metal foam in heat exchange applications is relatively recent,and commercially viable technology is yet under development and the subject of fundamental and applied research.Metal foam saturated with water can enhance both stagnant thermal conductivity and con-vective transport,but the relative importance of each has not been fully quantiﬁed and characterized for either forced or natural convection.The present paper was moti-vated by an interest in the application of metal foam in sen-sible heat water storage systems that operate on a charge–discharge cycle and rely on natural convection to deliver and remove energy via immersed heat exchanger(s).Our hypothesis is that the presence of the foam will enhance heat transfer coeﬃcients in such systems and thus improve the rate of both energy storage and release.As a ﬁrst step toward technology development,the heat transfer law for steady convection in saturated foam is needed.Based on the work of Liu et al.[1]for immersed tubes and tube bun-dles in a thermal store,the steady state heat transfer law is an adequate tool for system characterization owing to the low convective velocities and time scales associated with charge and discharge.A metal foam is a porous medium with high surface area per unit volume,high bulk porosity (e >0.9),and a struc-ture characterized by thin ﬁbers,or ligaments,of metal joining several others in a random manner throughout the volume.Another important parameter is pore density,commonly expressed as pores per inch (PPI).Metal foams are available in a range of PPI,with 5,10,20and 40PPI ratings.Metal foam made of high conductivity metals,e.g.,copper and aluminum,can be used to enhance heat transfer when the material is applied to a surface,e.g.,heat sinks and tubular heat exchangers.In a convective heat transfer application,both ﬂuid mechanical eﬀects and the thermophysical properties play a role in the enhancement or decrease of the convective heat transfer coeﬃcient under a given operating condition.The stagnant thermal conductivity of saturated metal foam has been the subject of both experimental and theo-retical research [2–4],but the relation of the conductivity to pore density,porosity,and thermal conductivity ratio,0017-9310/$-see front matter Ó2008Elsevier Ltd.All rights reserved.doi:10.1016/j.ijheatmasstransfer.2007.11.051*Corresponding author.Tel.:+16126269850;fax:+16126256069.E-mail address:jhd@ (J.H.Davidson)./locate/ijhmtAvailable online at International Journal of Heat and Mass Transfer 51(2008)3794–3802k s /k f ,is a subject of continuing study.A number of studieshave been conducted on enhancement of forced convection with metal foam e.g.,[5–12],but only a few investigators have reported studies of natural convection in metal foams [13–16]for the geometry and thermal boundary conditions relevant to the present study.Calmidi and Mahajan [2]developed a one-dimensional model for the stagnant thermal conductivity of aluminum foam with air and water as the interstitial ﬂuids.They assumed the foam structure to comprise periodic hexago-nal unit cells.Their model was validated experimentally,and a correlation for the conductivity was developed in terms of k s /k f and e .Bhattacharya et al.[3]replaced the cubic intersection of the ligaments with a spherical intersec-tion,which results in sixfold rotational symmetry.They estimated the geometric parameter required by the model by visual inspection.They proposed an empirical expres-sion for k m using their data for reticulated vitreous carbon and the data of Calmidi and Mahajan [2].Boomsma and Poulikakos [4]modeled the structure as tetrakaidecahe-drons (single complete cells consisting of six squares and six hexagons)with the ligaments represented by thin cylin-ders joined at cubic nodes.Their model predicts that when there is a large diﬀerence between the solid and the ﬂuid conductivity,the stagnant conductivity is dominated by that of the solid even at high porosity.These studies indi-cate stagnant thermal conductivity is independent of pore density.Phanikumar and Mahajan [13]report experiments and numerical analysis of buoyancy induced ﬂow in a high porosity metal foam block heated from below and sur-rounded on all other faces by ﬂuid.Their numerical model is based on local thermal non-equilibrium and includes form drag and viscous (Brinkman)terms in the momentum equation.They modeled aluminum–air,aluminum–water,nickel–water and reticulated vitreous carbon–air foams with PPI from 5%to 40%and porosity from 89%to 97%.The key result of their analysis is that the eﬀects of local thermal non-equilibrium (LTNE)are signiﬁparison of the ﬂuid Nusselt numbers (Nusselt number based on the conductivity of the ﬂuid alone)with and with-out metal foam indicates that the aluminum foam–water combination produces the highest enhancement (16times that without foam)in heat transfer coeﬃcient,followed by the nickel foam–water combination (9.5times)and then the aluminum foam–air combination (3.8times).From their experiments with aluminum–air,heat transfer rate increases as the porosity and the pore density areNomenclature A aspect ratio,D /LA m cross-sectional area of the metal foam c p speciﬁc heat at constant pressure C f Forcheimer coeﬃcient d p pore diameterDa Darcy number,K /L 2E enhancement factor,Eq.(4)E adv advective enhancement factor,Eq.(5)k f thermal conductivity of ﬂuid k d dispersion conductivityk m stagnant thermal conductivity K permeability L layer thicknessNu f average Nusselt number based on ﬂuid prop-erty,qL /(A m D T )k fNu m average Nusselt number based on k m ,Nu f k f /k m Pr Prandtl number,l c p /kPr e eﬀective Prandtl number,Pr m Da 1/2/C f Pr m porous medium Prandtl number,l c p /k m Pr p modiﬁed Prandtl number,Pr m Da À1/2/C f q heat transferRa f Rayleigh number based on the ﬂuid properties,g b f (T h ÀT c )L 3/(am )fRa m porous medium Rayleigh number,Ra f Da k Re K Reynolds number based on the permeability,q f u ﬃﬃﬃﬃK p l f=R 2square of the regression correlation coeﬃcientt timeT temperature uDarcy velocityGreek symbols a thermal diﬀusivity B thermal coeﬃcient of expansiond Tthermal boundary layer thickness D T temperature diﬀerence between the hot and thecold surfaces,T h ÀT ce porosity q density lf viscosity l 0eﬀective viscosity m kinematic viscosity k conductivity ratio,k f /k m Subscripts c cold,refers to the temperature of the boundingsurfacee equivalentf ﬂuid h hot,refers to the temperature of the boundingsurfaces solid m foam–water mediumV.Kathare et al./International Journal of Heat and Mass Transfer 51(2008)3794–38023795decreased.A decrease in porosity increases metal content and hence increases the stagnant conductivity,whereas a decrease in pore density reduces theﬂow resistance.Zhao et al.[14,15]report experiments and a numerical study of Be´nard equivalent convection in steel alloy foam with air as the interstitialﬂuid.In both the experiments and analysis,the eﬀects of Darcy and Rayleigh numbers are sought for foam of30–90PPI and5%and10%relative density.Their analysis[15]is based on LTNE,and owing to the lack of a reliable correlation for the Forcheimer coef-ﬁcient,C f,and the small velocities inherent in natural con-vection,they neglect the form drag term in the momentum equation but include dispersion based on the work of Georgiadis and Catton[17].Theyﬁnd that for a given foam–ﬂuid combination and for a givenﬂuid Rayleigh number,a critical value of Da exists which signals an increase of the eﬀective conductivity,i.e.,the initiation of convection.For larger Da,the eﬀective thermal conductiv-ity approaches a steady value asymptotically,which implies that the natural convection in a foam–ﬂuid combination behaves the same as that in aﬂuid layer with conductivity equal to the stagnant conductivity of the medium.For Ra m>100,Nu m increases with Ra f for a constant value of Ra m.The authors conclude that the eﬀect of increasing buoyancy at higher Ra f is greater than the eﬀect of decreas-ing Da on convective transport.Their model of thermal conductivity agrees with measured data[14]to within28%.Krishnan et al.[16]modeled the eﬀects of LTNE in a side heated two-dimensional foamﬁlled cavity with k s/ k f=103,1056Ra f6108,Da=10À2and10À3,Pr=1 and100,and d p/L=0.0135.Although their boundary con-ditions are not those of the present study,their results sug-gest that LNTE and the resulting inter-phase heat transfer can make a signiﬁcant contribution to the temperature dis-tributions in the solid andﬂuid phases.Temperature gradi-ents in the solid andﬂuid likewise exhibit their greatest diﬀerences within the thermal boundary layer and then converge to zero simultaneously in the central region.In comparison,numerous experimental and theoretical studies have been reported on natural convection in a sat-urated porous media comprising a packed bed heated from below[18–30].The dependence of the Nusselt number on the Rayleigh number is well understood when theﬂuid pressure drop can be expressed by Darcy’s law(i.e.,creep-ingﬂow).For very large Rayleigh number,when the form drag is signiﬁcant in determining theﬂow resistance of the porous medium,it has been suggested that there is an expli-cit dependence of Nusselt number on Rayleigh number as well as the porous medium Prandtl number and the Darcy number[25,26,28],but this aspect of natural convection in a packed bed has not been fully resolved.Further when Re K<1,the Darcyﬂow assumption is suﬃcient to describe the relation between the Darcy velocity and the pressure drop,but when Re K>10,the pressure drop is dominated by form drag(the Forcheimer eﬀect)[31].Metal foams produce a much diﬀerent convective heat transfer problem for buoyantﬂow owing to their ligament structure,high porosities and high k s/k f ratio.Based on numerical study of forced convection over aﬂat plate embedded in a porous medium,Vafai and Tien[32]claim that although the boundary eﬀect(Brinkman eﬀect)is not signiﬁcant forﬂow considerations,it can be signiﬁcant for heat transfer.In packed beds,the eﬀects of viscous drag are nulliﬁed by the eﬀects of higher porosity near the wall [33].However,for metal foam with uniform porosity and higher permeabilities,boundary eﬀects can play a signiﬁ-cant role in determining the heat transfer.The ligament geometry for most commercially produced metal foam is triangular[3],and estimated to produce larger pressure drop than that predicted by Darcy’s law even at low veloc-ities.This characteristic should produce lower convective transport and heat transfer.Howeverﬂow separation enhancesﬂuid mixing(dispersion).The relative importance of these competing eﬀects in natural convection needs to be examined more fully.Moreover,there is apparently no generally accepted range of Re K to distinguish the Darcy from the Darcy–Forcheimer regimes of convection.The objective of the present study is to develop correla-tions for free convection in water-saturated copper foam. Further,the degree to which metal foam can enhance the overall heat transfer coeﬃcient over a range of geometrical and thermophysical parameters is shown.Heat transfer measurements are reported in a cavityﬁlled with water-sat-urated copper foam and heated from below.Foam layers with uniform PPI,as well as layers in which the PPI were varied in well deﬁned sub-layers are used in the present study.2.Apparatus and procedureThe experimental apparatus comprises a well insulated acrylic cylinder of0.127m IDÂ0.00635m wall thickness with a heated lower boundary and a vertically adjustable cold upper boundary(Fig.1).A rubber coated thinﬂexible resistance heater(0.102m DIAÂ1.4mm)is located beneath a copper bottom plate,and a copper cooling coil is brazed to a copper top plate.A similar guard heater and a separator plate assembly at the bottom are used to drive the applied heatﬂux upwards through the foam. The resistance of the heaters is218X.The top plate is held at$288K with a cooling coiling coil brazed to the upper surface.The upper and lower plates have suﬃciently high thermal conductivity and diﬀusivity so that temperature variations across the surface do not exceed0.9K for the present experiments.A bleed valve on the upper surface allows the escape of any trapped air as the cavity isﬁlled with de-gassed water.In operation,a layer of insulation is wrapped around the outer surface of the cylinder.Individually calibrated Type E thermocouples(Chro-mega(T)-constantan)made of high grade36Ga wire were used for temperature measurements on the upper and lower surfaces.Each of these surfaces is a9.53mm thick copper plate with six thermocouple wells in each.For each plate, thermocouple junctions are located0.53mm beneath the3796V.Kathare et al./International Journal of Heat and Mass Transfer51(2008)3794–3802surface in contact with the metal foam–water medium. Three thermocouples are located at a radius of12.7and three at38.1mm.Similarly positioned thermocouples are located on the bottom plate beneath the surface.Six thermo-couples are located on each side of the acrylic separator plate (Fig.1).These measurements are used to determine heat loss through the bottom of the apparatus[34].Three thermocou-ples areﬁxed to the exterior surface of the cylinder to esti-mate heat loss through the sides.Heat loss was estimated by assuming1-D radial heat conduction through the cylin-der heatﬂux through the metal foam–water med-ium was determined by subtracting heat loss through the cylinder wall and bottom plate from the power setting of the primary heater.For the range of applied power in the present experiment,heat losses were on the order of6%or less.All thermocouples are mounted with Omega BondÒ101 (k=1W/m K).An ice bath provides a single reference tem-perature for all thermocouple measurements.Temperatures of the bounding surfaces were recorded at steady state for t>2h,and average temperatures on the upper and lower surfaces were used to determine the Rayleigh and average Nusselt numbers.The thermocouples were calibrated along with the data acquisition hardware using a high precision RTD.This procedure reduced the measurement uncertainty of each thermocouple to±0.04K.The uncertainty in the mean temperature of the isothermal boundaries includes the calibration uncertainty as well as the statistical error due to averaging temperatures along the surfaces.The total uncertainty is±0.9K at the95%conﬁdence level.Open cell copper foam disks made by ERG Aerospace, Inc.each0.0127m DIAÂ0.0254m and rated at10and 20PPI and91.6±0.2%porosity were stacked within the cylinder.Thermal bonding of the foam to the top and bot-tom plates was assured by$0.2mm of thermal paste (k=2.3W/m K).The thermal conductivities of the copper alloy and water at room temperature are391and0.58W/ m K,respectively and thus k$0.07.The overall Darcy number was varied by stacking the multiple foam disks to change the layer thickness,L,and by ordering the foam cylinders to change the PPI distribution within the overall foam layer(Table1).The Rayleigh number was varied by changing the heatﬂux from1280to5213W/m2and byFig.1.Cross section of experimental apparatus.Table1Foam layers with PPI distributions and key descriptive and dimensionless parametersFoam layer A e d pÂ103m KÂ107m2±0.1C f±0.005k m W/m K±0.44DaÂ105Ra fÂ10À6Ra m Pr m10PPI(L=0.0254m)50.92 2.54 1.60.0688.8325.40.75–2.612–440.49–0.54 20PPI(L=0.0254m)50.92 1.25 1.10.0838.8516.5 1.9–4.621–510.40–0.44 10PPI(L=0.0508m) 2.50.92 2.54 1.60.0688.83 6.310–2944–1220.44–0.54 20PPI(L=0.0508m) 2.50.92 1.25 1.10.0838.85 4.117–4043–1130.41–0.45 10PPI–20PPI–10PPI(each0.0254m thick;L=0.0762m)1.670.922.54 1.40.0748.83 2.449–10073–1960.40–0.4920PPI–10PPI–20PPI(each0.0254m thick;L=0.0762m)1.670.92 1.25 1.20.0788.842.154–15375–2160.37–0.4110PPI–20PPI–20PPI–10PPI (each0.0254m thick;L=0.1016m)1.250.92 2.54 1.30.0768.84 1.2110–25494–2120.45–0.49 V.Kathare et al./International Journal of Heat and Mass Transfer51(2008)3794–38023797changing the layer thickness,L.Aspect ratios fall in the range 1.256A 64,with 0.02546L 60.1016m.The stagnant thermal conductivity of the 10and 20PPI foams,k m ,was determined via measurement of heat trans-fer with a stable temperature gradient,i.e.,heating from above.To determine the permeability and the form drag coeﬃcient,pressure drop was measured across the foam in an air-ﬂow channel with Darcy velocities from 0.04to 1m/s.The reported values of K and C f were obtained from a regression analysis in the form of a quadratic expression for pressure drop per unit depth of foam.The stagnant thermal conductivity,the permeability and the Forcheimer coeﬃcient of each layer combination are reported in Table 1along with measurement uncertainty.Maximum mea-surement uncertainties in computed Darcy,Rayleigh,and Nusselt numbers are 8%,13%and 12%,respectively.Uncertainty in both Ra f and Nu f are 11%.3.Results3.1.Heat transfer correlationsNatural convection in a water layer (without foam)was determined to validate the experimental design and to ensure wall eﬀects are insigniﬁcant.Steady state Nusselt numbers are well correlated byNu f ¼ð0:10Æ0:02ÞRa 0:31Æ0:01f ;ð1Þwhere 4Â105<Ra f <3Â108,and R 2=0.996.Fig.2shows the present data and the correlation of Garon and Goldstein [35]are in good agreement.Fig.3shows the measured Nusselt and Rayleigh numbers in comparison to Elder’s correlation,Nu m =Ra m /40,for a packed bed of spheres [21].The Nusselt numbers predicted by Wang and Bejan’s correlation [28]match those predicted by Elder’s correlation for the present range of Ra m and Da .The data for layers in which the 10and 20PPI are adja-cent to the isothermal boundaries are distinguished on theplot by open and closed symbols,respectively.For Da =25.4Â10À5and 16.5Â10À5,the onset of convection can be observed at Ra m $40;for Ra m 640,Nu m =1.For Da <104,Ra m 640was not obtained experimentally due to unacceptable measurement uncertainty at low heat ﬂux.The onset of convection at Ra m $40is in agreement with linear stability analysis [19],and measurements obtained in several other experimental studies.Further the present data suggest the destabilizing eﬀect of the aspect ratio (1.25<A <4)[15]is nulliﬁed by the stabilizing eﬀect of low thermal conductivity ratio (k $0.07),which delays the onset of convection [29].For each PPI,Nu m increases with decreasing Da at a given Ra m .An explanation for this result lies in the deﬁnition of the porous medium Rayleigh num-ber.For a ﬁxed Ra m ,Ra f increases as the Da is decreased.The eﬀect of a decrease in Da is an increase in the ﬂow resis-tance.But the eﬀect of an increase in Ra f is an increase in the buoyancy force.Thus,the present results suggest that the eﬀects of increased buoyancy on heat transfer are stronger that the eﬀect of the increased resistance to ﬂow.This inter-pretation agrees with the numerical work of Zhao et al.[15].Fig.3also shows that for each Da and PPI,the Nusselt num-ber falls below the trend of the packed bed correlation at suf-ﬁciently large Ra m .There is a distinct diﬀerence in the trends for the layers in which the 10and 20PPI foam are adjacent to the boundaries.As shown in Fig.4,the data for both 10and 20PPI are well correlated in the form suggested by dimensional analysis in which a modiﬁed Prandtl number [28],Pr p =Pr m Da À1/2/C f ,is introduced,Nu m ¼ð0:007Æ0:005ÞRa 0:54Æ0:08m Pr 0:48Æ0:10p ;ð2Þwhere 446Ra m 6216,3796Pr p 61818,and R 2=0.960.Eq.(2)successfully correlates the 10and 20PPI data ontoNu f = 0.10Ra f 0.31Nu f = 0.13Ra f 0.293Garon and Goldstein (1973)1101001.0E+051.0E+06 1.0E+07 1.0E+08 1.0E+09N u fRa fFig.2.Measured Nusselt number for natural convection in a water layer(Eq.(1))compared to the correlation of Garon and Goldstein [35].3798V.Kathare et al./International Journal of Heat and Mass Transfer 51(2008)3794–3802a single relation.Alternatively,the data can be correlated using the product of the ﬂuid Rayleigh number and the conductivity ratio,and the eﬀective Prandtl number [26],Nu m ¼ð0:006Æ0:004ÞðRa f k Þ0:53Æ0:09Pr 0:6Æ0:2e ;ð3Þwhere 2.6Â1066Ra f 62.54Â108,0.026Pr e 60.11,0.0656k 60.068(based on temperature variations),and R 2=0.960.3.2.Heat transfer enhancementThe practical goal of inserting metal foam into a water layer is to increase heat transfer coeﬃcients over those obtainable with water alone.Thus,a measure of heat trans-fer enhancement can be seen if the present data are cast in terms of the Nusselt and Rayleigh numbers using ﬂuid properties.Fig.5shows Nu f versus Ra f ,along with Eq.(1)for a water layer.For any given Ra f ,the ﬂuid Nusselt number obtained with foam is larger than that for the water layer with the exception of a single measurement (Da =4.1Â10À5,Ra f =1.6Â107).For Da =25.4Â10À5and 16.5Â10À5,Nu f remains nearly constant even with an increase in Ra f .This behavior suggests heat transfer via conduction.In these cases,Ra m 640,and heat transfer enhancement is a result of the high stagnant conductivity of the water-saturated copper foam.However,for the remainder of the present data,Nu f increases with increasing Ra f .Comparison of the data for Da =6.3Â10À5,which corresponds to L =0.0508m and 10PPI foam,to the data for Da =4.1Â10À5,which corre-sponds to L =0.0508m and 20PPI foam,reinforces the fact that heat transfer enhancement with 10PPI foam is greater than that with 20PPI foam..The 10PPI foam has less sur-face area compared to the 20PPI foam but it has higher per-meability.We attribute the increase in heat transfer to the increase in permeability.This conclusion is also supported by the fact that at a given Ra f ,both Nu f and Nu m obtained with 10/20/10PPI layering (Da =2.4Â10À5)are larger than values obtained with 20/10/20PPI layering (Da =2.1Â10À5).To quantify the increase of heat transfer coeﬃcient with foam,an enhancement factor at a given ﬂuid Rayleigh number is deﬁned asE ¼Nu f ðÞfoam Nu f ðÞno foam Ra f¼q 0:10Ra 0:31fÀÁk f A m D T L Ra f:ð4ÞEnhancement factors are shown in Fig.6as a function of Ra f .In general,E >1and increases with increasing Ra f when Ra m >40.However,when Ra m 640(Da =25.4Â10À5and 16.5Â10À5),E decreases with increasing Ra f .In this case,prior to the initiation of convection,the ﬂuid Nus-selt number with foam remains almost constant (Fig.5),whereas the Nusselt number in a water layer without foam increases with increasing Ra f .For Da =4.1Â10À5and Ra f =1.6Â107,E <1,which suggests suppression of con-vective heat transfer with foam.It is also seen that the values123450100200300400500600700N u m1.22.12.44.16.316.525.4Ra m 0.54Pr p 0.48Nu m =0.007Ra m 0.54Pr p 0.48Da (x105)Fig.4.Overall heat transfer correlation of the present data.Nu f = 0.10Ra f 0.311101001.0E+051.0E+06 1.0E+071.0E+08 1.0E+09N u fRa f1.22.12.4 4.16.316.525.4Da (x105)Fig.5.Fluid Nusselt numbers with metal foam.The correlation shown is that for water without foam.Measurement uncertainties are maximum and minimum values.0.81.01.21.41.61.82.02.22.42.61.0E+051.0E+06 1.0E+07 1.0E+08 1.0E+09ERa f1.22.12.4 4.16.316.525.4Da (x105)Fig.6.Heat transfer enhancement with foam compared to heat transfer in a water layer without the foam.Measurement uncertainties are maximum and minimum values.V.Kathare et al./International Journal of Heat and Mass Transfer 51(2008)3794–38023799of E for Da =4.1Â10À5are less than the values for Da =6.3Â10À5,which supports the assertion that the 20PPI foam suppresses convective heat transfer.Another measure of heat transfer enhancement is the comparison of heat transfer with and without foam on the basis of the increment above conduction due to advec-tive transport at a given Ra f .For this purpose,the enhance-ment factor is,E adv ¼q Àk m A m D TL 0:10Ra 0:31f k f A m D T L ÀÁÀk f A m D T L Ra f¼Nu m À1ðÞk m ð0:10Ra 0:31f À1Þk fRa f :ð5ÞWhen E adv >1,advective heat transfer contributes to the enhancement.As shown in Fig.7,overall,E adv increases with Ra f .However,E adv >1only for Da =1.2Â10À5(10/20/20/10PPI,L =0.1016m)and 2.4Â10À5(10/20/10PPI,L =0.0762m).Otherwise,E adv <1,indicating that the presence of foam suppresses advective heat transfer even though the total heat transfer is enhanced,i.e.,E >1(Fig.6).For example,for Da =6.3Â10À5and Ra f =2.9Â107,E adv =0.9even though E =1.6.Thus,for this combination of parameters,heat transfer enhance-ment is due to the high thermal conductivity of the metal foam relative to that of water.4.DiscussionAs seen in Fig.3,at a given Darcy number,the Nusselt number at high Rayleigh number lies below the correla-tions proposed by Elder [21]and Wang and Bejan [28].Possible reasons for the measured decrease are the signiﬁ-cance of form drag and the viscous drag due to macro-scopic boundary layer formation (boundary eﬀects)at high Rayleigh numbers [25,26,28,32],the disruption of local thermal equilibrium conditions [22,27],and thinning of the thermal boundary layer to less than the pore scale so that the transport process near the isothermal surfaces approaches that of convection in water without foam [21].To determine which of these probable causes is most sig-niﬁcant for the present study,estimates of relevant param-eters are summarized in Table 2.These parameters are calculated using a nominal pore diameter estimated from the deﬁnition PPI of the foam and the mean temperature across the foam layer.The thermal boundary layer thick-ness is approximated by d T $L /2Nu m [21],and the velocity scale is estimated from l f u m K þq f C f u 2m ﬃﬃﬃﬃKp $q f g b D T :ð6ÞUsing this velocity scale,the ratio of form drag to the Darcy drag isForm drag Darcy drag $q f C f u 2m=ﬃﬃﬃﬃK p l f u m =K :ð7ÞA reasonable estimate of the viscous drag due to macro-scopic boundary layer formation (the Brinkman eﬀect)can be determined asViscous drag $l f u mðPr m d T Þ2;ð8Þwhere the dynamic viscosity,l f ,replaces the eﬀective dy-namic viscosity,l 0,and Pr m d T estimates the hydrodynamic boundary layer thickness.The ratio of the viscous drag due to the boundary eﬀect to the Darcy drag is Viscous drag Darcy drag $l f u m =Pr m d T ðÞ2l f u m =K:ð9ÞThe dispersion conductivity,k d ,is assumed to be of the form [5]k d ¼0:025q f c p u m ﬃﬃﬃﬃK p :ð10Þ0.00.20.40.60.81.01.21.41.0E+061.0E+071.0E+08 1.0E+09E a d vRa f1.22.12.4 4.16.316.525.4Da (x105)Fig.7.Enhancement of advective heat transfer with foam compared to that in a water layer without the foam.Measurement uncertainties are maximum and minimum values.Table 2The values of hydrodynamic and heat transfer parameters Foam Layerd T 10À2m u m Â10À3m/s k d Â10À1W/m K Form drag Darcy drag Brinkman drag Darcy drag10PPI (L =0.0254m) 1.1–1.23.3 1.40.090.00620PPI (L =0.0254m) 1.2–1.3 3.8 1.30.120.00510PPI (L =0.0508m) 1.1–2.1 1.7–4.50.7–1.90.04–0.130.001–0.00620PPI (L =0.0508m)1.5–2.5 2.2–4.20.8–1.40.06–0.130.001–0.00310PPI–20PPI–10PPI (each 0.0254m thick;L =0.0762m) 1.1–1.7 1.9–4.70.7–1.80.06–0.150.002–0.00820PPI–10PPI–20PPI (each 0.0254m thick;L =0.0762m)1.2–2.2 2.0–5.10.7–1.80.06–0.180.002–0.00610PPI–20PPI–20PPI–10PPI (each 0.0254m thick;L =0.1016m)1.3–1.81.9–4.00.7–1.50.05–0.110.002–0.0043800V.Kathare et al./International Journal of Heat and Mass Transfer 51(2008)3794–3802。

dnv 201.nor certificate of conformity 2014 90 eu f

Form code: MED 201.NORRevision: 2017-07Page 1 of 4Certificate No: MEDB00005BKApplication of: Directive 2014/90/EU of 23 July 2014 on marine equipment (MED), issued as "Forskrift om Skipsutstyr" by the Norwegian Maritime Authority. This Certificate is issued by DNV GL AS under the authority of the Government of Norway.This is to certify:That the Equivalent fixed gas fire extinguishing systems components (extinguishing medium, head valves and nozzles) for machinery spaces and cargo pump roomswith type designation(s) NOVEC ECS 500Issued toKidde-Fenwal, Inc.Ashland, MA , USAis found to comply with the requirements in the following Regulations/Standards: item No. MED/3.45. SOLAS 74 as amended Regulation II-2/10 & X/3, IMO MSC/Circ. 848, IMO MSC.1/Circ.1313, FSS Code 5 and 2000 HSC Code 7Further details of the equipment and conditions for certification are given overleaf.This Certificate is valid until 2025-09-10.Issued at Høvik on 2020-09-11DNV GL local station:Certification & Inspection ServicesApproval Engineer: Helge BjørnaråNotified Body No.:0575for DNV GL ASRoald Vårheim Head of Notified BodyThe mark of conformity may only be affixed to the above type approved equipment and a Manufacturer’s Declaration of Conformit y issued when the production-surveillance module (D, E or F) of Annex B of the MED is fully complied with and controlled by a written inspection agreement with a Notified Body. The product liability rests with the manufacturer or his representative in accordance with Directive 2014/90/EU.This certificate is valid for equipment, which is conform to the approved type. The manufacturer shall inform DNV GL AS of any changes to the approved equipment. This certificate remains valid unless suspended, withdrawn, recalled or cancelled.Should the specified regulations or standards be amended during the validity of this certificate, the product is to be re-approved before being placed on board a vessel to which the amended regulations or standards apply.Digitally Signed By: Hoff, Øyvind Location: DNV GL Høvik, Norwayon behalf ofJob Id: 344.1-009310-1Certificate No: MEDB00005BK Product description“Novec ECS 500”,is a fixed gas fire extinguishing system using fire extinguishing agent Novec 1230 stored in steel cylinders as liquid and pressurized with nitrogen and distributed through pipes and nozzles.The extinguishing concentration and nozzles are covered by this type approval certificate. Documentation for the other system components shall be submitted and approved for each project. The system is to be designed in accordance with IMO MSC/Circ.848 as amended by IMO MSC.1/Circ.1267 and IMO MSC.1/Circ.1316.The extinguishing agent, Novec 1230, is produced by 3M, Cordova, Illinois, USA.2)When calculated at 20°C. Ambient temperature to be determined case by case for each project3)NFPA 2001 (2008 Edition)The following associated companies are authorised by Kidde-Fenwal to apply this certificate: -Kidde-Fenwal Inc., Ashland, USA-Kidde Fire Protection, Stokenchurch, UKApplication/LimitationThe design gas concentration (diesel) shall be minimum 5.85% (applied on a net volume) and the maximum agent discharge time shall be 10 seconds. The extinguishing system shall be designed and installed according to SOLAS Ch. II-2, IMO MSC/Circ.848 as amended by IMO MSC.1/Circ.1267, IMO MSC.1/Circ.1316 and the Kidde manual.The following additional limitations will apply:A.Novec ESC 500 systems are not suitable for the ship’s cargo holds. If Novec ESC 500 systemsare installed inside cargo pump rooms, all components shall be certified for use in hazardousareas, the design gas concentration shall be increased and the system is subjected to case bycase approval.B.If Novec 1230 agent is used above its NOAEL (calculated on net volume at max expectedambient temperature), means should be provided to limit exposure (IMO MSC.1/Circ.1267, 6).In no case should Novec 1230 be used in concentrations above its LOAEL.C.Steel storage cylinders of size 10 lb (4.5 kg) to 900 lb (408 kg). Cylinders being 81 L or larger isonly accepted when arrangements are provided on board to ensure that cylinders can be easily moved (even to shore) for service and recharging. All cylinders shall be of the same size.D.Gas cylinders shall be delivered on board with a product certificate of the Society or with acertificate issued by a recognized certification authority according to national regulations based on the requirements of the design standard and marked accordingly π, UN or DOT.E.Cylinders are topped up with nitrogen to 34.5 bar (500 psi) at 21°C. The fill density shall bemaximum 1.12 kg/L. Cylinders are to be delivered with DNV product certificate or equivalentcertificates acceptable to the flag administration and class.F.Cylinders to be located in a separate room in accordance with SOLAS Ch. II-2 Reg. 10.4.3, ordistributed throughout the protected space in accordance with the requirements in IMOMSC/Circ.848 item 11 as amended by IMO MSC.1/Circ.1267. When distributed within theprotected space, the min extinguishing concentration (after any single failure) shall be 4.5 %.Job Id: 344.1-009310-1Certificate No: MEDB00005BKponents in the system will be regarded under pressure class II with a maximum designpressure of 40 bar (at 54 °C). Consideration will though be made for piping and couplings inside the protected space.H.The nozzles are to be located in accordance with the Kidde manual. A basic rule is that onenozzle can as a maximum cover an area of 5 m x 10 m. A 360° nozzle shall be located centrally in this area, the 180° nozzles on the sides (as applicable). The maximum cover height is 5 m.The minimum average nozzle pressure is 4.2 bar.I.Bilges (except open bilges in small volume engine rooms) are to be protected with a dedicatednozzle network.The following documentation is to be submitted to the flag administration in each case:1.Plans showing location of cylinders, piping, nozzles and release stations as well as the assembledsystem2.Capacity calculations, including hydraulic flow calculations.3.Plans defining release lines and alarm system.4.Material specification and dimensions for piping and specifications for all other components.5.Ship specific release procedures and post discharge ventilation procedures.6.Manual containing design, inspection, operation and maintenance procedures.7.Control arrangements for closure of openings and stop of fans and any pressure relief devices asper IMO MSC/Circ. 848, 13. These plans can also be supplied by yard.Testing at installations and periodical surveys-The system shall be tested as per maker’s manual both at installations and at periodical surveys, except that DNV do not require monthly content check of cylinders. The minimum test pressure is minimum 53 bar for any closed sections, whereas open section shall be tightness tested atminimum 7 bar.-The system is subject to biennual (every 2nd year) inspections by an approved service supplier.The attending surveyor will also apply requirement relevant for flag administration and / or class on newbuilding and ship in operation surveys.Type Examination documentationDesign, Installation, Operation and Maintenance Manual – Novec ECS 500, No. P/N 06-237589-001, dated May 2017 from Kidde.Report No. HAI Project #5087, dated 28 June 2002, from Hughes Associates, Inc., Baltimore, USA. (tested on U.S. Coast Guard’s Fire & Safety Test Detachment in Mobile, AL).Report No. 04-CRADA-RDC-001, dated 16 November 2004, from Kidde-Fenwal Inc., Massachusetts, USA. (tested on U.S. Coast Guard’s Fire & Safety Test Detachment in Mobile, AL, witnessed by UL).Test Report File EX4674, Project 04NK23160, dated 1 February 2005, from UL, Northbook, USA.Report No. 3026502, dated 24 March 2006, from FM Approvals, Norwood, USA.Test report File EX4674, project 4788267101, dated 30 March 2018, from UL, Northbook, USAKidde Fenwal component sheets, stamped July 2005.Tests carried outTested in accordance with IMO MSC/Circ.848 as amended by IMO MSC.1/Circ.1267 and MSC.1/Circ.1316.Job Id: 344.1-009310-1Certificate No: MEDB00005BK Marking of productMain components in the system are to be marked with name and address of manufacturer, type designation and Mark of Conformity (see first page).。

香茅醛生产工艺流程中需要氮气的原因

英文回答：Salmon formaldehyde， as an important chemical intermediate，has extensive applications in the fields of perfume， spices and medicine。

The production process includes two key steps：oxidation and dehydration。

In the oxidation response， the oxidation of the Malay acid is required to be the malate， while the dehydrogenization reaction converts the malate to fragrance。

Nitrogen plays an important role in the production process。

In the oxidation response， nitrogen is used to protect the response medium from the effects of oxygen and to ensure oxidation in water— and oxygen—free environments。

In the dehydrogen reaction， nitrogen can be effective in the smooth discharge of the product， maintaining positive pressure within the reactor and preventing the release of harmful gases。

Nitrogen has an important protective role inthe fragrance production process。

海诺·泰勒水源头说明书

Halsey Taylor Owners Manual Non-Refrigerated FountainsIMPORTANTALL SERVICE TO BE PERFORMED BY AN AUTHORIZED SERVICE PERSONFIG. 1TUBE ISSECUREDIN POSITIONSIMPLY PUSH INTUBE TO ATTACHPUSH IN COLLETTO RELEASE TUBEPUSHING TUBE IN BEFOREPULLING IT OUT HELPS TORELEASE TUBEFIG. 2 OPERATION OF QUICK CONNECT FITTINGSOVL - E OVL - SIMPORTANT! INSTALLER PLEASE NOTE.THE GROUNDING OF ELECTRICAL EQUIPMENT SUCH AS TELEPHONE, COMPUTERS, ETC. TO WATER LINES IS A COMMON PROCEDURE. THIS GROUNDING MAY BE IN THE BUILDING OR MAY OCCUR AWAY FROM THE BUILDING. THIS GROUNDING CAN CAUSE ELECTRICAL FEEDBACK INTO A FOUNTAIN, CREATING AN ELECTROLYSIS WHICH CAUSES A METALLIC TASTE OR AN INCREASE IN THE METAL CONTENT OF THE WATER. THIS CONDITION IS AVOIDABLE BY USING THE PROPER MATERIALS AS INDICATED. ANY DRAIN FITTINGS PROVIDED BY THE INSTALLER SHOULD BE MADE OF PLASTIC TO ELECTRICALLY ISOLATE THE FOUNTAIN FROM THE BUILDING PLUMBING SYSTEM.NOTE: WATER FLOW DIRECTION BUILDING WATER INLET SERVICE STOP(NOT FURNISHED)1/4" O.D. TUBE WATER INLET TO COOLER 3/8" O.D. UNPLATED COPPER TUBE CONNECT COLD WATER SUPPLYFIG. 3OVL - SOVL - ELEGEND:A = 1-1/4" O.D. Waste Tube (Trap & Elbow Not Provided)B = 3/8" O.D. Unplated Copper Tube Connect (Water Inlet)Fig. 4INSTALLATION INSTRUCTIONS1. This fountain is to be mounted on a smooth, flat, finished wall surface, with adequate support structure.2. Establish rim height fountain is to be mounted.3. Refer to rough-in for plumbing.4. Locate and install trap. (Trap not furnished.)5. Install shut-off valve on building water supply. (Shut-off valve not furnished.)6. Remove access panel from bottom of fountain.7. Locate and install fountain using 3/8" (10 mm) (minimum) lag screws or bolts (not furnished).CAUTION: This fountain is rated for inlet water pressure of 20-90 PSI. Should the inlet water supply exceed 90 PSI, a pressure reducing regulator should be used.8. Connect fountain to building supply line with a shut-off valve and install a 3/8" (10 mm) unplated copper water line between the valve and fountain. Remove any burrs from outside of water line. Insert water line to a positive stop, approximately 3/4" (19 mm) on inlet side of strainer. DO NOT SOLDER TUBES INSERTED INTO THE STRAINER AS DAMAGE TO THE O-RINGS MAY RESULT .9. To remove waste elbow, remove (4) screws (item 18) and drop bottom plate (item 20) and push bar (item 2) down. Waste elbow slip nut (item 13) is now accessible. Connect fountain drain.10. Turn “ON” water supply and check all connections for leaks.11. Adjust projector stream height.12. If needed, adjust push arm/regulator clearance by turning phillips head screw (item 26) on regulator bracket assy. (item 30). Turning screw CCW should correct water coming out of projector continuously.13. Reinstall access panel using screws provided.TROUBLE SHOOTING AND MAINTENANCEOrifice Assy: Mineral deposits on orifice can cause water flow to spurt or not regulate. Mineral deposits may be removed from the orifice with a small round file or small diameter wire. CAUTION: DO NOT file or cut orifice material.Stream Regulator: If orifice is clean, regulate flow as in instructions above. If replacement is necessary, see parts list for correct regulator part number.Actuation of Quick Connect Water Fittings: Fountain is provided with lead-free connectors which utilize an o-ring water seal. To remove tubing from the fitting, relieve water pressure, push in on the gray collar while pulling on the tubing.(see Fig.2) To insert tubing, push tube straight into fitting until it reaches a positive stop, approximately 3/4".CAUTION: To preserve the quality and keep this AZTEC GOLD finish clean and spot free, clean this surface with only mild detergent or window cleaner and polish with a soft cloth. DO NOT use any abrasive cleaners or harsh chemicals. They WILL damage the finish!Fig. 523241514RegulatorMounting BracketCARE AND MAINTENANCE OF HALSEY TAYLOR MARBLYTE FOUNTAINSMarblyte provides an extremely durable , non-porous surface which resists staining. Care is very simple. Routine cleaning with a soft sponge or cloth, or with water or non-abrasive aerosol foam cleaner, is all that is normally needed to give many years of trouble free service. Cleaners left standing on the fountain surface can dull the surface finish. Be certain to rinse all cleaning agents completely and polish with a soft cloth. Harsh abrasivecleaners are not required and should not be used. Mild abrasives such as liquid automotive cleaning compound or baking soda paste will remove simple scratches and stains. Cigarette burns can normally be removed without noticeable effect. Deeper scratches or gouges can be corrected with fine grit sandpaper (240 grit then 400 grit) or a green scotchbrite pad. To maintain or regain luster and make cleaning easier, periodic applications of automobile wax or like products will keep the finish looking like new.DESCRIPTION26990C 26988C 55836C 55991C 51546C 45396C 51544C 10032274056016027050864045400C 10157054056051575C 11034620855010163745155016163730864045398C 45683C 45682C 10002334056016157080855061314C 50986C 27006C 27342C 55951C 55952C 55953C 27000C 27344C 70861C 55840C 55839C 27002C 27338C 27004C 27340C 28328C 15005C 40045C 27008C 70856C 70854C 50198C 51667C 28327C 28326C 55996C 70793C 56159C 56092C12345678910111213141516171819202122232425262728293031NS NS NS NSP ART NO.Bottom Cover (OVL-S)Bottom Cover (OVL-E)Push Arm ActuatorPush Arm Actuator - AG BubblerBubbler - AG Bubbler- MARBL Bubbler Gasket Strainer PlateStrainer Plate - AG Drain Gasket Packing Ring Drain Nut Friction Ring Drain PlugDrain Plug/Strainer - AG Waste Elbow (OVL-E)Waste Elbow (OVL-S)Waste Tube Gasket Slip Nut RegulatorRegulator Holder BasinBasin - AGBasin - GRAY MRBL Basin - BLACK MRBLBasin - GOLDEN SAND MRBL Basin LinerBasin Liner - AG Screw # 10-24 x 2T op Plate - Actuator Bottom Plate - Actuator Arm w/Weldnuts (OVL-E)Carrier Arm - AG (OVL-E)Arm w/Weldnuts (OVL-S)Carrier Arm - AG (OVL-S)Regulator Mounting Bracket Nut - Retaining Nut Hex - UNPLTD Reaction BracketScrew #10-24 x .38 PHMS Rod - Pivot Bushing SnapBumper - Reg. Valve Assy Arm - Reg. Activating Arm - Reg. Adjustment Strainer Elbow-1/4"Bubbler Nipple AssyTubing - Poly (Cut to Length)ITEM NO.PARTS LISTFOR PARTS CONTACT YOUR LOCAL DISTRIBUTOR OR VISIT OUR WEBSITE WWW.HALSEYTA 2222 CAMDEN COURT OAK BROOK, IL 60523630.574.3500PRINTED IN U.S.A.FIG. 6FIG. 719220292629262730223125Stream Height Adjustment18510891213678111See Fig. 721See Fig. 53, 41617See Fig. 6。

Investigating the Properties of Nanofluids

Investigating the Properties ofNanofluids随着科技的发展，人类对于纳米技术的应用越来越深入。

其中一项应用就是纳米流体（nanofluids）技术。

纳米流体就是将微米或纳米级别的颗粒分散于传统的流体中。

这个技术在热传导、摩擦损失等领域有着广泛的应用。

在工程领域中，纳米流体的热传导性能引起了我们的特别关注。

热传导系数决定了材料的导热性能，它的值越大表明材料导热能力越好。

因此，热导率也被广泛地应用在各种领域，例如电池、半导体等。

通过添加纳米颗粒到传统的流体中，可以极大地提高流体的热传导性能。

研究表明，与传统的热传导介质相比，纳米流体的热传导系数要高得多。

这是因为纳米颗粒具有巨大的比表面积；微米或者更大的颗粒的表面积更小，因此纳米颗粒的比表面积较大，导致表面能更强，从而对周围的流体产生更多的振动和搅拌，提高了流体的热导率。

在进行纳米流体的研究时，需要通过一系列的实验来测试纳米流体的物理和化学特性。

以下我们将介绍一些测试方法：1. 热导测试热导测试是测试纳米流体中热传导性能的重要方法。

通常采用热板法或热阻法进行测试。

在热板法中，将一个热板加热至一定的温度，待热板温度稳定后，将添加不同纳米颗粒的流体涂在热板上，并通过传感器进行测试。

在热阻法中，测量热板两面的温差来计算材料的热导率。

2. 稳定性测试稳定性测试是指纳米颗粒在流体中的分散情况。

稳定性好的纳米流体在使用时更为方便和可靠。

通常采用离心法、显微镜、光学薄膜厚度检测器等进行测试。

3. 流变性测试流变性测试是指测量纳米流体的黏度、流动性等指标。

黏度的大小反映了流体内部分子之间的摩擦力大小。

流动性的指标反映了流体内部分子的运动速度。

具有良好流动性的纳米流体在传输和运用时更为方便。

总结：纳米流体技术是一项有潜力的应用技术。

通过添加纳米颗粒到传统的流体中，可以大大提高流体的热传导性能。

但同时需要进行一系列的测试，以确保纳米流体的物理和化学特性稳定，促进其在各个领域的应用。

农药剂型种类、代码及定义中英文对照表

DT
片剂(直接使用)
（Tablet for direct application）
使用前无需加水稀释调配，直接施用于田野或水中之片状制剂（Formulation in the form of tablets to be applied individually and directly in the field, and/or bodies of water, without preparation of a spraying solution or dispersion）。
水悬剂专供种子处理用者（A stable suspension for application to the seed either directly or after dilution）。
FU
熏烟剂（Smoke generator）
燃烧后释出含有效成分烟雾之可燃制剂，通常为固体（A combustible formulation, generally solid, which upon ignition releases the active ingredient(s) in the form of smoke），依其外形可细分为：熏烟罐（Smoke tin, FD）；熏烟烛（Smoke candle, FK）；熏烟匣（Smoke cartridge, FP）；熏烟棒（Smoke rodlet, FR）；熏烟片（Smoke tablet, FT）；熏烟丸（Smoke pellet, FW）。
CP
触杀粉剂（Contact powder; Formerly know as tracking powder (TP)）
杀鼠或杀虫配方供直接使用之粉剂（Rodenticidal or insecticidal formulation in powder form for direct application）。

MAG精练剂

4.4 T/C (12x10/104x57+64”)
CPB process→ Hot bleaching CPB: Padding the working solution→ Batching for 24hours→ Hot washing four times→Cold washing→Squeezing excess water. Recipe (g/l) 1 2 NaOH(100%) 40 40 H2O2(100%) 10 25 Foryl MAG 8 18 Activator S 1
Hot bleaching: Padding the working solution→ Steaming 50min →Hot washing four times→Cold washing→Drying. Recipe (g/l) Stabilol NC H2O2(100%) Cottoclarin 88ECO
1 0.2 12 15 3 50 18
2 20 50 18
Results:
Recipe Whiteness (CIE D65) Residual H2O2 Rating of residual starch Absorbency 15sec (cm) 30sec 60sec 30min 1 69 1.98-3.96 5 0.6 0.9 1.2 3.1
14
2 10 8 8 7 2 81 1.98 4 2.7 3.4 4.3 13.3
Results Recipe Whiteness (CIE D65) Residual peroxide Residual starch 15sec Absorbency 30sec (cm) 60sec 30min
4.3 Cotton/nylon

3M Novec Engineered Fluids 产品介绍.pdf_1701735150.111

Aerosol formulations using3M™ Novec™ Engineered FluidsAerosol formulation is a challenging science, especially when you factor in the need for non-flammability, low toxicity, high solubility, environmental sustainability and much more. At 3M, we've made challenging sciences our business and developed a comprehensive line of low environmental impact carrier solvents for aerosols –3M™Novec™ Engineered Fluids. With the use of high global warming potential (GWP) solvents becoming increasingly regulated and restricted, it’s time to make the switch to Novec fluids, with all the performance, safety and sustainability benefits you need.Properties Unit3M™ Novec™ Engineered Fluids7100 /7100DL a7200 /7200DL a7500 7700 71D90bBoiling Point °C (F) 61 (142) 76 (169) 128 (262) 167 (332) 43 (109) Pour Point °C (F) -135 (-211) -138 (-216) -100 (-148) -50 (-58) -45 (-49) Molecular Weight g/mol 250 264 414 528 97 / 250c Maximum Use Temperature °C (F) <150 (302) <150 (302) <200 (392) <200 (392) <150 (302) Flash Point d°C (F) None None None None None Vapor Pressure kPa 27 16 2.1 <0.1 54 Heat of Vaporization kJ/kg 112 119 89 83 268 Liquid Density g/cm3 1.51 1.42 1.61 1.80 1.26 Coefficient of Expansion K-10.0018 0.0016 0.0013 0.0011 - Absolute Viscosity cP 0.58 0.58 1.24 4.54 0.40 Specific Heat J/kg-K 1183 1220 1128 1040 - Surface Tension mN/m 13.6 13.6 16.2 18 21.1Solubility of Water in Fluid ppm byweight95 92 45 14 -Solubility of Fluid in Waterbyweight12ppm<5ppm<4ppb<1ppb<6300ppm eDielectric Strength Range, 0.1"gapkV > 25 > 25 > 25 > 25 - Worker Exposure Guideline f ppm 750 200 100 TBD g200 / 750hOzone Depletion Potential ODP 0 0 0 0 0Global Warming Potential i GWP 297 57 100 436 32Not for specification purposes. All values @ 25°C unless otherwise specified.a Novec Engineered Fluids with a DL designation are higher purity versions of that product number for deposition applications when high purity materials are needed.b 90% by weight trans-1,2-dichloroethylene; 10% by weight of Novec 7100 fluidc 97 g/mol= trans-1,2-dichloroethylene molecular weight; 250 g/mol = Novec 7100 fluid molecular weightd Per closed cup flash point, tested in accordance with ASTM D3278 test method.e <6300 ppm, reference tDCE solubilty in water from "Industrial Solvents Handbook", Flick, E.W. (ed.) 1985f Recommended parts per million (ppm) for eight-hour average worker exposure per day as established by 90-day inhalation study. Study methodology based on American Industrial Hygiene Association exposure guidelines.g Novec 7700 fluid is low in acute toxicity and most applications have very low inhalation exposure. It is for these reasons that occupational exposure limits (OELs) have not yet been determined for this product.h trans-1,2-dichloroethylene has an 8-hour. time-weighted average (TWA) exposure guideline (EG) of 200 / EG for Novec 7100 fluid is 750.i GWP-100 year ITH, CO2 = 1.0, per IPCC 2013, with the exception of Novec 7100 and 7100DL fluids and blends containing Novec 7100 fluid, which note IPCC 2007.Aerosol formulations using3M™ Novec™ Engineered FluidsBelow are some recommendations to help with your formulations. 3M technical representatives are also available to help determine which 3M™ Novec™ Engineered Fluid is best for your specific needs and to help you with customizing your aerosol solution.Properties3M™ Novec™ Engineered Fluids7100 /7100DL7200 /7200DL 7500 7700 71D90Fluorocarbon solubility High High High High LowHydrocarbon solubility Medium Medium Low Low Very HighPlastic/elastomer compatibility High High Very High Very High LowApplicationsAerosol cleaners ●●●Aerosol coatings ●●●Dry lubricant aerosols /polytetrafluoroethylene (PTFE)●●●●Dissolving fluorochemicals ●●●●Dissolving hydrocarbons ●●●Reducing aerosol formulationflammability●Improving aerosol CARB VOCcompliance1●Extending dry time ●●Replacement forChlorofluorocarbons (CFCs) ●●●Hydrochlorofluorocarbons (HCFCs) ●●●Hydrofluorocarbons (HFCs) ●●Perfluorinated chemicals (PFCs) ●●●●Perfluoropolyethers (PFPEs) ●●n-propyl bromide (nPB)●1 Does not exceed the volatile organic compound (VOC) limits set by the California Environmental Protection Agency Air Resources Board for aerosol formulations. It is essential that the user evaluate the 3M product to determine whether it is fit for a particular purpose and that the end formulation meets the environmental and regulatory requirements of your area.Have questions? Need technical assistance? Contact your 3M technical service representative.We’re here to help.IMPORTANT NOTICE: The technical information, recommendations and other statements contained in this document are based upon tests or experience that 3M believes are reliable, but the accuracy or completeness of such information is not guaranteed. Contact your local 3M representative or visit /Novec for more information. Warranty and Limitation of Liability: if there is a defect in this product, your exclusive remedy shall be product replacement or refund of the purchase price. 3M MAKES NO OTHER WARRANTIES OR CONDITIONS, INCLUDING ANY IMPLIED WARRANTY OR CONDITION OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 3M will not be liable for any direct, indirect, special, incidental or consequential damage related to the use of this product.Electronics Materials Solutions Division 3M Center, Building 224-3N-11St. Paul, MN 55144-10001-800-810-8513/novec©2016 3M. All rights reserved.3M and Novec are trademarks of 3M Company.60-5002-0824-89/2018 ●●。

水凝胶敷料英文综述投稿

水凝胶敷料英文综述投稿Water-based hydrogel dressings have been widely used in the field of wound care due to their excellent moisture-retaining properties and ability to provide a moist environment for wound healing. These dressings are composed of a network of hydrophilic polymers that can absorb and retain large amounts of water, keeping the wound bed hydrated and promoting autolytic debridement. Additionally, the cooling effect of water evaporation from the dressing can provide pain relief for the patient.From a material science perspective, the structure and composition of water-based hydrogel dressings play acrucial role in their performance. Various polymers such as alginate, carboxymethyl cellulose, and gelatin are commonly used in the fabrication of hydrogel dressings, eachoffering unique properties that affect the dressing's absorbency, adhesiveness, and biocompatibility.In terms of clinical application, water-based hydrogeldressings have shown efficacy in the management of both acute and chronic wounds, including burns, ulcers, and donor sites. Their ability to provide a moist wound environment supports the body's natural healing processes and can contribute to faster wound closure and reduced scarring. Moreover, the cooling sensation they provide can offer comfort to patients with painful wounds.It is important to consider the regulatory aspects of water-based hydrogel dressings, as different countries may have specific requirements for the approval and marketing of medical devices. Understanding the regulatory landscape is essential for researchers and manufacturers looking to develop and commercialize these dressings.In conclusion, water-based hydrogel dressings offer a promising approach to wound care, leveraging their moisture-retaining properties, cooling effect, and biocompatibility to support the healing process. Continued research and development in this field can lead to further innovations and improvements in the design and clinical application of these dressings.。

Solstice Performance Fluid High Performance (PF-HP

Solstice® Performance Fluid High Performance (PF-HP) in Oxygen Line CleaningSolvents|High Performance; Critical CleaningIt is critical that oxygen lines and parts used in oxygen service are completely clean and free of debris. Solstice PF-HP is compatible and well suited for oxygen line cleaning due to its ability to effectively remove contamination from the desired lines or parts and then be completely dried. The oxygen-enriched autoignition temperature of Solstice PF-HP was determined to be 210 °C (410 °F) by ASTM G 72 at 1500 psig.Solstice PF-HP is manufactured and specially packaged to deliver product with a NVR specification of less than 2 parts per million (ppm).Solstice PF-HP is a pure component solvent that contains no stabilizers or additives. After comparison testing, NASA has stated that “Stabilizer additives, although < 1% of the solvent, can affect NVR residues and must be considered and controlled for oxygen system cleaning applications”. 2Designed with critical cleaning in mind, it can be used in vapor degreasing equipment, cold cleaning, NVR verification and tube flushing.Fluid PropertiesSelect physical properties of Solstice PF-HP are given in Table 1. The vapor pressure of Solstice PF-HP will facilitate quick evaporation and drying of cleaned materials.Honeywell’s Solstice® PF-HP (High Performance) is an ultra clean (very low non-volatile residue content), highly-effective, nonflammable cleaning solution, with a favorable toxicity profile and low environmental impact. In 2015, NASA announced it had tested Solstice Performance Fluid (PF), stating it is a “preferred replacement for cleaning and non-volatile residue (NVR) verification sampling of NASA propulsion oxygen systems hardware, ground support equipment (GSE), and associated test systems. Solstice PF-HP is recommended for cleaning and NVR sampling in applications at NASA propulsion test facilities where AK-225G is currently used”. 1 The tests performed by NASA were designed to determine the compatibility of Solstice PF with commonly-used metals and other materials used in its systems. Solstice PF demonstrated good cleaning efficiency (>97 %) and had the most favorable safety, health and environmental profile compared to other cleaning solutions investigated .Solstice® Performance Fluid – High Performance (PF-HP) in Oxygen Line CleaningEnvironmental and Safety ProfileIt is extremely important to consider the effect on the surrounding area and the safety of individuals who works and come in contact with a cleaning solution. The environmental impact of Solstice PF-HP has been studied and is shown to have negligible ozone depletion and a very low global warming potential (GWP). The MIR also indicates that Solstice PF-HP will create less ground level ozone or smog than ethane. Designated as VOC exempt by the United States EPA and California’s South CoastAir Quality Management District (SCAQMD). Solstice PF-HP does notTable 1. Physical Properties of Solstice PFexhibit any flashpoint or vapor flame limits – it has been determined that it has no vapor flame limits at temperatures up to 100°C in ASTM E 681 testing. Table 2 lists a few of the important environmental and safety properties of Solstice PF-HP.Cleaning CapabilitiesSolstice PF-HP is able to dissolve a number of typical soils that are encountered in military and aerospace cleaning. Table 3 lists a selection of the soils that have been tested and can be easily dissolved by Solstice PF-HP. The solubility characteristics allow for Solstice PF-HP to be used in a wide variety of military and aerospace cleaning operations.Wetting IndexSolstice PF-HP has a very high wetting index value as compared with many other products available today as well as phased out legacy fluids. The wetting index is a numerical indicator of how well a fluid will effectively wet the surface of the parts being cleaned and facilitates the rapid cleaning of intricate pieces and parts containing small channels. The wetting index is determined by the following equation: (1000 • density) ÷ (surface tension • viscosity).ConformanceThere are a wide variety of tests and specifications that a solvent must conform to in order to be acceptable for use in military and aerospace applications. Solstice PF-HP has been tested and found to conform to many of the solvent specifications typically used in military and aerospace applications. Table 1 lists the specifications, ASTM method and the result in testing Solstice PF-HP.As shown in Table 5, Solstice PF-HP conforms to all standards tested with theexception of the stress crazing test on acrylic plastics.Table 2. Environmental and Safety Properties of Solstice PFTable 4: Wetting Index of Solstice PF-HPTable 3. Example of soils that can be readily cleaned with Solstice PFTable 5. Results of Solstice PF TestingCompatibilityMetals commonly used in the aerospace industry were tested for compatibility with Solstice PF-HP. The solvent was shown to be compatible with all the metals listed (see Table 6) when tested according to the ARP 1755B method. NASA also ran metal compatibility with Solstice PF-HP using the metals listed (see Table 7), and the solvent showed good compatibility with each of them.1The information provided herein is believed to be accurate and reliable, but is presented without guarantee or warranty of any kind, express or implied. User assumes all risk and liability for use of the information and results obtained. State-ments or suggestions concerning possible use of materials and processes are made without representation or warranty that any such use is free of patent infringement, and are not recommendations to infringe any patent. The user should not assume that all safety measures are indicated herein, or that other measures may not be required.Version 3 | 2/2016© 2016 Honeywell International Inc.Solstice is a registered trademark of Honeywell International, Inc.Contact Honeywell to Learn MoreTable 6. Compatibility of Solstice PF According to SAE Aerospace Reommended Practices (ARP) 1755B Table 7. Metal Compatibility Completed at NASA¹ withSolstice PF at 72°F for 168 HoursSummarySolstice PF-HP is a safe and effective choice for cleaning parts which will be used in oxygen service. NASA has recently designated the solvent as the preferred alternative to AK-225G in oxygen system cleaning. Solstice PF-HP has an ideal combination of high cleaning performance, non-flammability, low toxicity, and low volatility, which allows it to be used toclean tight spaces and then be removed to leave a pristine surface.1. Replacement of Hydrochlorofluorocarbon-225 Solvent for Cleaning and Verification Sampling of NASA Propulsion Oxygen Systems Hardware, Ground Support Equipment, and Associated test systems; H.D. Burns, M. A. Mitchell, J. H. McMillian, B.r. Farner, S. A. Harper, S.F. Peralta, N. M. Lowery, H.R. Ross, A. Juarez; NASA/GP01502015-218207.2. HCFC-225 Solvent Replacement Project -Cleaning and Verifying MSFC/SSC Propulsion Oxygen Systems; Nikki M. Lowrey/Jacobs ESSSA Group, Mark A. Mitch-ell/NASA-MSFC, George C. Marshall Space Flight Center. Presented at ASTM G04 Education Session ASTM Committee, Week April 28-30, 2015.。

苯丙胺类滥用药物简述

苯丙胺类滥用药物简述作者：许荣富，姚付军，张茜， Xu Rongfu， Yao Fujun， Zhang Qian作者单位：首都师范大学化学系,北京,100037刊名：北京教育学院学报(自然科学版)英文刊名：JOURNAL OF BEIJING INSTITUTE OF EDUCATION(NATURAL SCIENCE)年，卷(期)：2007,2(3)1.Forsling M L;Falion J K;hah D The effect of 3,4-Methylenedloxymethamphetamine (MDMA,"ecstasy") and its metabolites on neurohypophysial hormone release from the isolated rat hypothalamus[外文期刊] 2002(03)2.郭菘;杜万君;张大明甲基苯丙胺类混合物-摇头丸滥用方式及其对精神活动的影响[期刊论文]-中国药物依赖性杂志 2000(02)3.Cheng S;Nolte H;Otton S V Simultaneous gas chromatographic determination ofmethamphetamine,amphetamine and their phydroxylated metabolites in plasma and urine[外文期刊] 19974.李金苯丙胺类物质及其检测[期刊论文]-中国药物依赖性杂志 2003(01)5.Gianpiero Boatto;Maria Virginia Faedda;Amedeo Pau Determination of amphetamines in human whole blood by capillary electrophoresis with photodiode array detection[外文期刊] 2002(6)6.An-Shu liau;Ju-Tsungg Liu;Li-Chan Lin Optimization of a simple method for the chiral separation of methamphetamine and related compounds in clandestine tablets and urine samples by β-cyclodextrine modified capillary electrophoresis:a complementary method to GCMS[外文期刊] 2003(1)7.Véronique Piette;Frans Parmentier Analysis of illicit amphetamine seizures by capillary zone electrophoresis 20028.Emmanuel Varesio;Jean-Luc Veuthey Chiral separation of amphetamines by high-performance capillary electrophoresis 19959.Pizarro N;Ortuno J;Farre M Determination of MDMA and its metabolites in blood and urine by gas chromatography-mass spectrometry and analysis of enantiomers by capillary electrophoresis[外文期刊] 2002(03)10.刘伟;沈敏SPME-GC/NPD法快速分析尿液中苯丙胺类化合物[期刊论文]-法医学杂志 1999(02)11.Knut Einar Rasmussen;Stig Pedersen-Bjergaard;Mette Krogh Development of a simple in-vial liquidphase microextraction device for drug analysis compatible with capillary gas chromatography,capillary electrophoresis and high-performance liquid chromatography[外文期刊] 2000 12.Yoo Jeong Heo;Yoon Sung Whang;Moon Kyo In Determination of enantiomeric amphetamines as metabolites of illicit amphetamines and selegiline in urine by capillary electrophoresis using modified β-cyclodextrin[外文期刊] 200013.Satoshi Chinaka;Scishi Tanaka;Nariaki Takayama Simultaneous chiral analysis of methamphetamine and related compounds by capillary electrophoresis[外文期刊] 2000(1)14.沈敏体内滥用药物分析 200315.王玫GDX-403固相萃取分析尿、血中安非他明类毒品 1999(02)17.Peter R Stout;Carl K Horn;Kevin L Klette Rapid simultaneous determination ofamphetamine,methamphetamine,3,4-methylenedioxyamphetemine,3,4-methylenedioxymethamphetarnine in urine by solid-phase extraction and GC-MS:a method optimized for high-volume laboratories 2002(01)18.沈敏;沈保华;向平血、尿中甲基苯丙胺以及代谢物产物苯丙胺的分析研究[期刊论文]-法医学杂志 1997(03)19.Nobuyuki Nagasawa;Mikio Yashiki;Yasumasa Iwasaki Rapid analysis of amphetamines in blood using head space-solid phase microextraction and selected ion monitoring[外文期刊] 199620.Kathryn S;Kalasinsky;Barry Levine Fourier transform infrared spectroscopy techniques for the analysis of drugs of abuse 199321.杨小红;田开珍;王峰高效液相色谱-二极管阵列检测法同时测定临床中毒患者血浆中的甲基苯丙胺及苯丙胺[期刊论文]-色谱 2003(09)22.C Cháfer-Pericás;P Campíns-Faleó;R Herráez-Hemández Application of solid-phase microextraction combined with derivatizafion to the determination of amphetaminesby liquid chromatography 200423.H P Hendrickson;A Milesi-Hallé;E M Laurenzana Development of a liquid chromatography-tandem mass spectrometric method for the determination of methamphetamine and amphetamine using small volumes of rat serum[外文期刊] 2004(2)24.F Sadeghipour;J L Veuthey Sensitive and selective determination of methylenedioxylated amphetamines by high-performance liquid chromatography with fluorimetrie detection[外文期刊]1997(1/2)25.Ming-Ren Fuha;Chiuan-Hung Haunga;Shiang-Ling Lin b Determination of free-form amphetamine in rat brain by ion-pair liquid chromatography-electrospray mass spectrometry with in vivo microdialysis[外文期刊] 200426.Rosa Herraez-Hernandez;Pilar Camp?ns-Falco Derivatization of ephedrine with o-phthaldialdehydefor liquid chromatography after treatment with sodium hypochlorite[外文期刊] 200027.Dinesh Talwar;Ian D Watson;Mike J Stewart Routine analysis of amphetamine class drugs as their naphthaquinone derivative in human urine by high-performance liquid chromtography[外文期刊] 1999 28.Y McAvoy;M D Cole;O Gueniat Analysis of amphetamines by supercritical fluid chromatography,high-Performance liquid chromatography,gas chromatography and capillary zone electrophoresis,apreliminary comparison[外文期刊] 199929.Palar Campims-Falco;Adela Sevillano-Cabeza;Carmen Molins -Legua Amphetamine and methamaphetamine determination in urine by reversed-phase high-performance liquid chromatography with simultaneous sample clean-up and derivatization with 1,2-naphthoquinone 4-sulphonate on solid-phase catridges[外文期刊] 199630.Katja Pihlainen a b;Risto Kostiainen b Effect of the eluent on enantiomer separation ofcontrolled drugs by liquid chromatography-ultraviolet absorbance detection-electrospray ionisation tandem mass spectrometry using vancomycin and native -cyclodextrin chiral stationary phases[外文期刊] 200431.Myung Ho Hyun;Sang Cheol Han;Bruce H Lipshutz Liquid chromatographic resolution of racemic32.Myung Ho Hyun;Jong Sung Jin;Hye Jin Koo Liquid chromatographic resolution of racemic amines and amino alcohols on a chiral stationary phase derived from crown ether[外文期刊] 199933.M Katagi;H Nishioka;K Nakajima Direct high-performance liquid chromatographic and high-performance liquid chromatographic -thermospray -mass spectrometric determination of enantiomers of methamphetamine and its main metabolites amphetamine and p-hydroxymethamphetamine in human urine[外文期刊] 199634.Chandrani Gunaratna;Peter T Kissinger Investigation of stereoselective metabolism of amphetamine in rat liver microsomes by microdialysis and liquid chromatography with precolumn chiral derivatization[外文期刊] 199835.Gianpiero Boatto;Maria Virginia Faedda;Amedeo Pau Determination of amphetamines in human whole blood by capillary electrophoresis with photodiode array detection[外文期刊] 2002(6)36.F P Smith;S Turrina;V Equisetto Complementary use of capillary zone electrophoresis and micellar electrokinetic capillary chromatography for mutual confirmation of results in forensic drug analysis [外文期刊] 1996(1/2)37.Tuulia Hy?tyl?inen;Heli Sirén;Marja -Liisa Riekkola Determination of morphine analogues,caffeine and amphetamine in biological fluids by capillary electrophoresis with the marker technique[外文期刊] 1996(1/2)38.Ulli Backofen;Frand-Michael Matysik;Werner Hoffmann Analysis of illicit drugs by nonaqueous capillary electrophoresis and electrochemical detection 200039.V Craige Trenerry;James Robertson;Robert J Wells Analysis of illicit amphetamine seizures by capillary electrophoresis[外文期刊] 1995(1)urent Geiser;Samir Cherkaoui;Jean -Luc Veuthey Simultaneous analysis of some amphetamine derivatives in urine by uonaqueous capillary electrophoresis coupled to electrospray ionization mass spectrometry[外文期刊] 200041.Ulli Backofen;Frand-Michael Matysik;Werner Hoffmann Analysis of illicit drugs by nonaqueous capillary electrophoresis and electrochemical detection 200042.Jeongeun Choi;Choonmi Kim;Myung Ja Choi Immunological analysis of methamphetamine antibody andits use for the detection of mehtamphetamine by capillary electrophoresis with laser-induced fluorescence[外文期刊] 199843.An-Shu Liau;Ju-Tsungg Liu;Li-Chan Lin Optimization of a simple method for the chiral separationof methamphetamine and related compounds in clandestine tablets and urine samples by β-cyclodextrine modified capillary electrophoresis:a complementary method to GCMS[外文期刊] 2003(1) 44.Iio R;Chinaka S;Takayama N Simultaneous chiral analysis of methamphetamine and related compounds by capillary electrophoresis/mass spectrometry using anionic cyclodextrin[外文期刊] 2005(01)45.Juraj Sevcík;Zdenek Stránsky;Benno A Ingelse Capillary electrophoretic enantioseparation of selegiline,methamphetamine and ephedrine using a neutral β-cyclodextrin epichlorhydrin polymer 1996 46.Yoo Jeong Heo;Yoon Sung Whang;Moon Kyo In Determination of enantiomeric amphetamines as。

Supercritical Fluids and Their Applications

Supercritical Fluids and TheirApplicationsSupercritical fluids are substances that are compressed to a state where they exhibit both liquid and gas properties. This state is achieved when the temperature and pressure of the substance are above their critical point. In this state, the fluid has unique properties that make it useful in a variety of applications.One of the primary applications of supercritical fluids is in the extraction of natural products. Supercritical CO2 extraction is a widely used technique for the extraction of essential oils, flavors, and fragrances from plant materials. The process is highly efficient and produces extracts that are free from residual solvents, making them safe for use in food, cosmetics, and pharmaceuticals.Supercritical fluids also find extensive use in the production of fine chemicals and pharmaceuticals. Supercritical antisolvent precipitation is a technique used to produce nanoparticles of drugs and other active ingredients. The technique involves the addition of a supercritical fluid to a solution of the active ingredient in a solvent. This causes the solute to precipitate out in the form of nanoparticles. The resulting particles have a higher surface area and are more bioavailable, making them more effective than their bulk counterparts.Supercritical fluids also have applications in the field of materials science. Supercritical CO2 is used as a processing medium for polymers, metals, and ceramics. The technique involves the use of a supercritical fluid as a solvent or as a plasticizer to facilitate the processing of the materials. This results in materials with unique properties such as improved mechanical strength, thermal stability, and electrical conductivity.Another application of supercritical fluids is in the field of environmental remediation. Supercritical water oxidation is a technique used to treat hazardous waste. The process involves the use of supercritical water as a medium for the destruction ofhazardous substances such as pesticides, solvents, and explosives. The process is highly effective and produces no harmful byproducts.Supercritical fluids also find applications in the field of energy. Supercritical CO2 is being explored as a potential replacement for traditional refrigerants in air conditioning and refrigeration systems. The use of supercritical CO2 as a refrigerant has the potential to reduce energy consumption and lower greenhouse gas emissions.In conclusion, supercritical fluids are a versatile class of substances with unique properties that make them useful in a variety of applications. From chemical production to environmental remediation, their potential for use in a wide range of fields makes them an exciting area of research. As research in the field continues, we can expect to see more innovative uses for supercritical fluids in the future.。

煤制油工业火灾扑救探析_王秋彧

灭火指挥与救援　煤制油工业火灾扑救探析王秋(内蒙古自治区消防总队,内蒙古呼和浩特010051) 摘　要:简述了煤制油的发展历程和工艺特点,分析了煤制油工业的火灾危险性和火灾特性,总结和探讨了煤制油工业火灾的扑救方法,对引发的相关问题进行了讨论。

关键词:煤制油;火灾危险性;火灾扑救中图分类号:X924.4,T U998.1 文献标志码:B文章编号:1009-0029(2009)10-0777-042009年4月8日,伊泰煤制油有限责任公司发生火灾。

内蒙古消防总队调集呼和浩特、包头、鄂尔多斯三市消防力量,成功将大火扑灭,避免了连环爆炸和次生灾害,且无一伤亡,保护财产价值27亿元,成功保住了我国第一条煤炭“间接液化”完全自主技术生产线。

这是我国乃至世界首例煤制油工业的大型火灾,也是一起具有石油化工特点的油罐火灾。

目前,消防部队尚无处置煤化工火灾的实战经验,这起火灾的扑救经验非常珍贵,笔者就此做一总结。

1　煤制油技术发展概况“煤制油”亦称“煤液化”,即以煤炭为原料,在一定反应条件下生产液体燃料和化工原料的过程。

煤液化技术通常分为“煤直接液化”和“煤间接液化”两种工艺。

伊泰公司采用“煤间接液化”工艺。

1.1　煤间接液化技术发展历程煤间接液化技术是由德国科学家Frans Fischer 和Hans Tr opsch于1923年首先发现并以他们名字命名的,简称“F-T合成”或“费-托合成”。

1936年德国建成世界上第一座煤间接液化工厂。

1955年南非Sasol 公司利用煤间接液化技术生产出汽油、煤油等产品,其煤液化技术处于世界领先地位。

20世纪70年代,世界各国开始重视煤液化技术。

目前,将煤间接液化技术投入商业生产的主要有南非、荷兰和美国的几家公司。

2001年,国家科技部和中国科学院联合启动了煤制油重大科技项目。

内蒙古煤炭资源丰富,产煤成本相对较低,发展煤制油工业具有得天独厚的优势。

目前,内蒙古已建有神华煤直接液化和伊泰煤间接液化等项目,煤制油产业化步伐正在加快。

关于冰浆的英文专利

关于冰浆的英文专利Title: An Overview of Ice Slurry-related English PatentsIntroduction:Ice slurry, as an innovative and energy-efficient way to store and transport cold energy, has gained significant attention in recent years.The following document provides an in-depth exploration of the English patents related to ice slurry technology, highlighting the various applications, manufacturing processes, and advancements in this field.I.Applications of Ice Slurry:1.Refrigeration and Air Conditioning: Ice slurry is used as a cooling medium in refrigeration and air conditioning systems, offering higher energy efficiency and lower environmental impact compared to traditional refrigerants.2.Food and Beverage Industry: It is widely employed in the food and beverage industry for preserving and transporting perishable goods, ensuring quality and safety throughout the supply chain.3.Medical and Pharmaceutical: Ice slurry finds applications in medical and pharmaceutical sectors for storing biological samples, vaccines, and other temperature-sensitive pharmaceutical products.II.Manufacturing Processes:1.Direct Contact Method: This method involves mixing water and afreezing agent, such as ethylene glycol or propylene glycol, in a suitable ratio.The mixture is then cooled to form ice slurry.2.Indirect Contact Method: In this process, a heat exchanger is used to cool the water without direct contact with the freezing agent.This method is suitable for large-scale production and offers better control over the ice slurry quality.III.Advancements in Ice Slurry Technology:1.Enhanced Freezing Agents: Researchers have developed new freezing agents with improved thermal properties, such as higher latent heat of fusion and lower freezing points, to enhance the efficiency of ice slurry systems.2.Nanotechnology: The use of nanoparticles in ice slurry has shown promising results in improving the heat transfer performance, reducing the energy consumption, and extending the storage life of the ice slurry.3.Phase Change Material (PCM) Incorporation: Incorporating PCMs into ice slurry can increase the energy storage capacity and provide better temperature control, making it suitable for various applications, including renewable energy storage.IV.English Patents on Ice Slurry:Several English patents have been filed on ice slurry-related technologies.These patents include:1."Ice Slurry Production Apparatus and Method" (Patent Number:XXXXXXXX): This patent discloses a novel apparatus and method for producing ice slurry, focusing on energy efficiency and scalability.2."Enhanced Heat Transfer Ice Slurry" (Patent Number: XXXXXXXX): This patent describes the use of nanoparticles in ice slurry to improve heat transfer performance and reduce energy consumption.3."PCM-Enhanced Ice Slurry for Energy Storage" (Patent Number: XXXXXXXX): This patent presents a PCM-incorporated ice slurry for enhanced energy storage and better temperature control in various applications.Conclusion:The ice slurry technology has shown immense potential in various industries, offering an energy-efficient and environmentally friendly alternative to traditional cooling methods.The English patents discussed in this document highlight the advancements and innovations in ice slurry-related technologies, providing a valuable resource for researchers and industry professionals.。

全氟聚醚润滑油在高温下的腐蚀性研究

2019年4月Apr．2019润滑油LUBＲICATING OIL第34卷第2期Vo l．34，No．2DOI：10．19532/j．cnki．cn21-1265/tq．2019．02．006文章编号：1002-3119（2019）02-0023-04全氟聚醚润滑油在高温下的腐蚀性研究王俊英1，2，张香文1，2（1．天津大学化工学院先进燃料与化学推进剂重点实验室，天津300072；2．天津化学化工协同创新中心，天津300072）摘要：全氟聚醚（简称PFPE）是未来航空涡轮发动机润滑的最佳候选耐高温功能液。

但在高温下，有金属铁及其合金存在时，全氟聚醚会发生降解并腐蚀金属铁及其合金。

对具有不同平均分子量的K型全氟聚醚基础油在300ħ下的腐蚀性进行了测试，显示全氟聚醚对金属的腐蚀性与其平均分子量无关。

合成出全氟聚醚修饰的胺、硫醚、苯醚和噻唑4种腐蚀抑制剂，重点评价了它们的抗腐效果。

添加剂的加入量对其抗腐蚀性能也有一定影响。

结果表明噻唑类添加剂能够完全抑制全氟聚醚基础油腐蚀不锈钢试片。

关键词：全氟聚醚；高温；腐蚀性；添加剂中图分类号：TE626．34文献标识码：AStudy on Corrosion of Perfluoropolyalkylether Lubricants at High TemperatureWANG Jun－ying1，2，ZHANG Xiang－wen1，2（1．Key Laboratory for Advanced Fuel and Chemical Propellant，School of ChemicalEngineering and Technology，Tianjin University，Tianjin300072，China；2．Collaborative InnovativeCenter of Chemical Science and Engineering（Tianjin），Tianjin300072，China）Abstract：The perfluoropolyalkylether（PFPE）fluids are the best candidates for high temperature functional fluids with excel-lent potential for aeronautical application as gas turbine engine oils．However，when exposed to high temperature with ferrous and alloys，PFPE oils would decompose and cause metal corrosion．In this work，the corrosion properties of K－PFPE based oil with different average molecular weight were tested at300ħ，and they were independent of the molecular weight．Four addi-tive materials for the K－PFPE based oil were synthesized，an amine，a sulfur ether，a phenyl ether and a thiazole．The focus of this work was to evaluate the anti－corrosion effect of four additives．As well，the amount of additives would affect their anti －corrosion effect．The results demonstrated that the thiazole－additive can completely inhibit PFPE－based oil corroding stain-less steel．Key words：PFPE；high－temperature；corrosion；additive0引言随着现代航空航天业的发展，涡轮发动机的设计与研发中对推重比的要求进一步提高，其工作温度也随之升高［1］。

Liberty Medical PressureGuard 和 Custom Care 转换面膜说明

Foam: a solid
FoF•aomianmh:ib:aitassoisdoleiladidl pressure redistribution
Air: a fluid
Air•:Afaiarﬂci:ulitiadatﬂesuidideal pressure redistribution
• four body-length air cylinders provide greater air displacement and better weight distribution than typical side-toside cylinder configurations
The design team at Span-America knew there was a better way. The result is the revolutionary PressureGuard Custom Care Convertible series. Its innovative design maximizes the essential component of true air therapy: Air!
�� ensure outstanding comfort and stability. �� increase patient safety. �� avoid patient entrapment.
1 “’Constant Force Technology’ vs. Low-Air-Loss Therapy in the Treatment of Pressure Ulcers.” Raquel Branom, RN, BSN, CWOCN, and Laurie M. Rappl, PT, CWS: Ostomy/Wound Management 2001;47(9):38-46.

The properties and uses of ionic liquids

The properties and uses of ionicliquidsIonic liquids have been gaining increasing attention due to their unique properties and promising applications in various fields. In this article, we will explore the properties and uses of ionic liquids.What are ionic liquids?Ionic liquids (ILs) are a type of salt that exists in the liquid state at or near room temperature. Unlike traditional salts, which are crystalline and have a high melting point, ILs are composed of large, asymmetric organic cations and often small, inorganic anions. Due to their low volatility and high thermal stability, they have been coined as "molten salts" or "designer solvents", as they can be tailored to possess specific chemical, physical, and functional properties.Properties of ionic liquids1. Low vapor pressureOne of the most striking properties of ionic liquids is their low vapor pressure. Unlike most organic solvents, ILs do not evaporate easily under ambient conditions. This property makes them ideal for use in closed systems, especially in situations where toxic and volatile organic solvents pose a significant threat to safety and health.2. High thermal stabilityIonic liquids are also highly thermally stable, which means they can withstand high temperatures without decomposing. This property enhances their utility in chemical reactions that require high temperatures, such as polymerization, catalysis, and electrochemistry.3. High polarityIonic liquids are typically highly polar, which means they have a strong ability to dissolve polar compounds such as salts, acids, and bases. This property makes them ideal solvents for many chemical reactions and separations.4. Tailorable propertiesThe properties of ionic liquids can be easily tailored to meet specific needs depending on the application. For instance, the choice of cation and anion can be varied to modify the solubility, viscosity, and other properties of the liquid. Additionally, the functionalization of the cation or anion can introduce additional properties such as hydrophobicity, conductivity, and selectivity.Uses of ionic liquids1. Green solventsIonic liquids have been hailed as "green solvents" because of their unique properties and low environmental impact. They have been used as replacements for traditional organic solvents such as chloroform, benzene, and toluene, which are known to be toxic, flammable, and environmentally hazardous.2. CatalysisIonic liquids have been found to be excellent catalysts for a wide range of chemical reactions. Due to their high thermal stability, they can withstand high temperatures, and the tailorable properties make them suitable for various reactions such as oxidation, reduction, and polymerization.3. Energy storageIonic liquids have great potential for use in energy storage applications. They possess high ionic conductivity, which makes them suitable for use as electrolytes in batteries and supercapacitors. Furthermore, the tailorable properties make it possible to design ionic liquids with specific functions such as electrochemical stability, viscosity, and miscibility.4. SeparationIonic liquids have been used as alternative solvents for separation processes due to their high selectivity and low volatility. They have been found to be useful for extracting compounds from natural sources, such as flavonoids from plants, and separating rare earth elements from ores.ConclusionIonic liquids possess unique properties that make them highly versatile and promising for various applications, including green solvents, catalysis, energy storage, and separation. The tailorable properties of ionic liquids offer a wide range of opportunities for future research and developments in the field. With further advances in their synthesis, understanding, and applications, ionic liquids are expected to play an increasingly important role in many industrial and technological sectors.。

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氮气泡沫流体
冲砂工艺技术在港西油田的应用
单位：井下作业公司
作者：张风彩刘刚
摘要
大港油田开发已逐步步入中后期，经过多年的开采，油层压力普遍降低，在修井维护作业过程中采用水基液体洗井时修井液漏失仍然非常严重，有些井甚至无法建立循环，给冲砂作业带来很大难度。

为了解决这一难题，井下作业公司进行了氮气泡沫流体技术的研究并在港西油田进行了氮气泡沫冲砂工艺的应用，取得了较好的效果，解决了漏失井冲砂难以建立循环、地层砂难以返出地面的问题，提高了作业效果，并缩短了作业时间，开井生产时产能恢复期明显缩短。

关键词：漏失井；氮气泡沫流体；氮气泡沫冲砂工艺
Abstract
With the continued development of the Dagang oilfield,the formation pressure of the reservoir decreased gradually,so during the workover process,a large number of killing fluid leaked into the formation,which can cause formation damage and result that the curd and sand cannot be washed out effectively. especially in the low-pressure absorption well and the horizontal well, because the well washing circulation cannot be set up,affecting the normal production of the wells.This paper takes the in-depth analysis of the technical difficulties existed in low pressure well,optimizing the nitrogen foam sand-washing well technology through laboratory experiment and carrying out field application test.The result shows that nitrogen foam sand-washing technology can effectively reduce the leakage of flushing fluids, reduce formation damage and improve the sand carrying capacity,ensuring the rapid recovery of the oil production.
Key words: Dagang oilfield；nitrogen foam；low-pressure absorption well；sand-washing.
1、绪论
大港油田经过多年的开采，油层压力普遍降低：一方面，产层压力系数降低，远低于正常地层压力系数，许多井压力系数仅能达到0.6-0.7左右；另一方面多半生产井出现了出水量增加，含砂增多等生产问题，生产周期缩短，修井作业频次加大。

目前的修井维护作业过程中多数采用水基修井液，漏失非常严重，部分井采用了暂堵液、胶结砂堵漏等工艺，但也仅能建立循环，修井液漏失仍然非常严重。

造成油井维护后产能恢复期长，冲砂后由于地层砂难以返出地面，短期内又砂埋油层，油井维护频率高。

针对这些难题，必须首先解决在维护作业过程中修井液的漏失问题。

为此，井下作业公司利用氮气泡沫流体冲砂工艺技术，成功地在港西油田进行了现场应用。

2、氮气泡沫流体冲砂工艺的原理及特性
1.主要设备及工艺原理
起泡剂：表面活性剂，减小水的表面张力，形成稳定的气泡。

泡沫：均匀的细小泡沫，气泡直径小于0.05mm。

工艺原理：泡沫发生器内有气液混合腔和气液搅拌叶轮。

气体直接进入配气管，分散成小气泡。

液体以旋转方式进入，带动气体混合。

初步混合的泡沫液经过固定式叶轮后多次改变方向并产生与水的搅拌，气体粉碎，在水中成微气泡。

气体在内中心管，液体在外中心管，依靠小孔原理，和发泡剂、稳泡剂形成细小泡沫，再借助外中心管的多级阻流板，产生漩流作用，促使泡沫均匀，不聚集。

最终形成稳定的泡沫。

2.氮气泡沫流体的特性
（1）泡沫对地层渗透率有选择性，堵大不堵小，即泡沫对高渗层具有较强的
封堵作用，而对低渗层的封堵作用较弱，起到调剖作用。

（2）泡沫对油水层有选择性，泡沫遇油消泡，遇水稳定，堵水层不堵油层，泡沫对水层具有较强的封堵作用。

（3）泡沫流体具有较高的表观粘度，携带能力强(携液、携固)，返排时可将井底积液和固体污染物携带出井筒。

（4）泡沫流体密度低且方便调节，可以达到需要的井筒密度和井底压力，特别适用于低压井和漏失井。

（5）泡沫流体中气体膨胀能为返排提供能量，使得返排更彻底，适用于低压井和漏失井。

3、氮气泡沫流体冲砂工艺在港西油田的应用情况
1.施工井简况
西40-6-11H井是港西开发区一区三断块的一口油层套管为177.8mm的水平井，最大井斜93.78度，水平段长524m。

油层段为筛管完井，深度1240-1470m。

该井正常生产时液量为17.9m3，日产油6.1吨，今年3月份该井生产全水无油，4月初井口出泥浆后关井停产。

目前该井不出，初步分析砂卡泵。

起原井后探砂面深度为800m，冲砂至1215m，井口返出泥浆和地层砂，怀疑是井内油层套管破裂，为了解除油层堵塞，降低修井液对地层的污染，提高携砂能力，防止冲砂过程中造成卡管，决定对该井实施氮气泡沫冲砂工艺措施。

2.施工过程情况简述
2011年7月9日采用清水55m3、发泡剂325Kg，氮气车配合反冲砂，出口返出液体25m3后见到均匀泡沫，下放管柱冲砂至1388m遇阻，冲砂井段1215-1388m，冲砂过程中出口返出地层砂及泥浆，共计 3.5m3，泡沫出口压力4-5MPa，排量17-23m3/h，泡沫密度0.75g/cm3，累计用时3.5h。

3.现场应用效果
（1）西40-6-11H如果使用常规水基冲砂作业需要用时5h以上，而氮气泡沫冲砂作业用时3.5h，与常规水基冲砂作业相比施工用时缩短了41.7%；累计冲出地层砂3.5m3，与冲砂井段对应的井筒体积相当，泡沫液将井筒内地层砂全部携带出地面。

表1 西40-6-11H井泡沫冲砂施工参数记录
（2）从图1可以看出该井在投产后产量恢复很快，7月14日下完井，7月15日出油1.98吨，7月18日该井日产液达16.2 m3，日产油6.63吨，恢复到了停产前的日产水平，产能恢复期为4天，和常规的产能恢复期7天相比，产能恢复期缩短了42.8%；7月21日日产液已达16.5m3，日产油7.98吨，超过停产前的日产量的30%，达到了增油的效果。

图1 西40-6-11H井采油曲线
4、结论
1.泡沫流体冲砂工艺完全满足冲砂工艺要求，很好的解决了漏失井冲砂不能建立有效循环、冲砂不彻底以及水平井清水携啥能力弱等问题。

2.高粘泡沫流体有超强携带能力和清洗能力，大大提高了作业效果、缩短了作业时间；同时由于近井地带的堵塞物被清理，作业后产日油量也得到了提高。

3.泡沫的密度低，减少了冲砂过程中冲砂液的漏失，对地层污染小，开井生产时产能恢复期也明显缩短。

4.在修井维护作业过程中，需要尽可能采用氮气泡沫流体进行洗井、冲砂作业，根据地层情况选择合理的泡沫液类型，减少水基修井液对地层的污染，有利于稳定并提高单井日产量。

5.鉴于泡沫流体特殊的特性，下步将对泡沫酸化技术、泡沫混排技术等方面进行研究与应用，为大港油田稳定并提高单井日产量贡献更多的技术对策。