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Intermediate Accounting Chapter10 课后习题答案

Chapter 10 Property, Plant, and Equipment and Intangible Assets: Acquisition and Disposition QUESTIONS FOR REVIEW OF KEY TOPICSQuestion 10-1The difference between tangible and intangible long-lived, revenue-producing assets is that intangible assets lack physical substance and they primarily refer to the ownership of rights. Question 10-2The cost of property, plant, and equipment and intangible assets includes the purchase price (less any discounts received from the seller), transportation costs paid by the buyer to transport the asset to the location in which it will be used, expenditures for installation, testing, legal fees to establish title, and any other costs of bringing the asset to its condition and location for use. Question 10-3The cost of a developed natural resource includes the acquisition costs for the use of land, the exploration and development costs incurred before production begins, and the restoration costs incurred during or at the end of extraction.Question 10-4Purchased intangibles are valued at their original cost to include the purchase price and all other necessary costs to bring the asset to condition and location for use. Research and development costs incurred to internally develop an intangible asset are expensed in the period incurred. Filing and legal costs for both purchased and developed intangibles are capitalized.Question 10-5Goodwill represents the unique value of the company as a whole over and above all identifiable tangible and intangible assets. This value results from a company’s clientele and reputation, its trained employees and management team, its unique business location, and any other unique features of the company that can’t be associated with a specific asset.Because goodwill can’t b e separated from a company, it is not possible for a buyer to acquire it without also acquiring the whole company or a substantial portion of it. Goodwill will appear as an asset in a balance sheet only when it was paid for in connection with the acquisition of another company. The capitalized cost of goodwill equals the purchase price of the acquired company less the fair value of the net assets acquired. The fair value of the net assets equals the fair value of all identifiable tangible and intangible assets less the fair value of any liabilities of the selling company assumed by the buyer.Answers to Questions (continued)Question 10-6A lump-sum purchase price generally is allocated based on the relative fair values of the individual assets. The relative fair value percentages are multiplied by the lump-sum purchase price to arrive at the initial valuation of each of the separate assets.Question 10-7Assets acquired in exchange for deferred payment contracts are valued at their fair value or the present value of payments using a realistic interest rate. Theoretically, both alternatives should lead to the same valuation.Question 10-8Assets acquired through the issuance of equity securities are valued at the fair value of the securities if known; if not known, the fair value of the assets received is used.Question 10-9Donated assets are valued at their fair values.Question 10-10When an item of property, plant, and equipment is sold, a gain or loss is recognized for the difference betwee n the consideration received and the asset’s book value. Retirements and abandonments are handled in a similar fashion. The only difference is that there will be no monetary consideration received. A loss is recorded for the remaining book value of the asset.Question 10-11The basic principle used to value assets acquired in a nonmonetary exchange is to use the fair value of asset(s) given up plus (minus) monetary consideration - cash - paid (received).Question 10-12The two exceptions are (1) when fair value is not determinable and (2) when the exchange lacks commercial substance.Question 10-13GAAP require the capitalization of interest incurred during the construction of assets for a company’s own use as well as for assets constructed for sale or lease. Assets qualifying for capitalization exclude inventories that are routinely manufactured in large quantities on a repetitive basis and assets that are in use or ready for their intended purpose. Only assets that are constructed as discrete projects qualify for interest capitalization.Answers to Questions (continued)Question 10-14Average accumulated expenditures for a period is an approximation of the average amount of debt the company would have had outstanding if it borrowed all of the funds necessary for construction. If construction expenditures are incurred equally throughout the period, the average accumulated expenditures for the period can be estimated by adding the accumulated expenditures at the beginning of the period to the accumulated expenditures at the end of the period and dividing by two. If expenditures on the project are unequal throughout the period, individual expenditures, perhaps expenditures grouped by month, should be weighted by the amount of time outstanding until the end of the construction period or the end of the company’s fiscal year, whichever comes first. Question 10-15Applying the specific interest method, the interest rate on any construction related debt is used up to the amount of the construction debt and any excess average accumulated expenditures is multiplied by a weighted-average interest rate of all other debt. The weighted-average method multiplies average accumulated expenditures by the weighted-average interest rate of all debt, including any construction-related debt.Question 10-16GAAP defines research and development as follows:Research is planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service or a new process or technique or in bringing about a significant improvement to an existing product or process.Development is the translation of research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or use.Question 10-17GAAP specifically excludes from current R&D expense the cost of property, plant, and equipment and intangible assets that have “alternative future uses” beyond the current R&D project. However, the depreciation or amortization of these assets will be included as R&D expenses in the future periods the assets are used for R&D activities. If the asset has no alternative future use, its cost is expensed as R&D immediately.Question 10-18GAAP requires the capitalization of software development costs incurred after technological feasibility is established. Technological feasibility is established “when the enterprise has completed all planning, designing, coding, and testing activities that are necessary to establish that the product can be produced to meet its design specifications including functions, features, and technical performance requirements.” Costs incurred after technological feasibility but before the product is available for general release to customers are capitalized as an intangible asset. These costs include coding and testing costs and the production of product masters. Costs incurred after commercial production begins usually are not R&D expenditures.Answers to Questions (concluded)Question 10-19The cost of developed technology is capitalized and expensed over its expected useful life. Developed technology relates to those projects that have reached technological feasibility. Before 2009, the cost of in-process R&D was expensed in the period of the acquisition. Now, the cost of in-process R&D is capitalized and treated as an indefinite life intangible asset and not amortized. If the R&D project is completed successfully, we switch to the way we account for developed technology and amortize the capitalized amount over the estimated period the product or process developed will provide benefits. If the project instead is abandoned, we expense the entire balance immediately. Research and development costs incurred after the acquisition to complete the project are expensed as incurred, consistent with the treatment of any other R&D not acquired in an acquisition. Question 10-20Other than software development costs incurred after technological feasibility has been established, U.S. GAAP requires all research and development expenditures to be expensed in the period incurred. IAS No. 38draws a distinction between research activities and development activities. Research expenditures are expensed in the period incurred. However, development expenditures that meet specified criteria are capitalized as an intangible asset.Question 10-21The periodic amortization percentage for capitalized computer software development costs under U.S. GAAP is the greater of (1) the ratio of current revenues to current and anticipated revenues or (2) the straight-line percentage over the useful life of the software. This approach is allowed under IFRS, but not required.Question 10-22The successful efforts method allows companies to capitalize only exploration costs resulting in successful wells. The full-cost method allows companies to capitalize all exploration costs incurred within a geographical area.BRIEF EXERCISESBrief Exercise 10-1Capitalized cost of the machine:Purchase price $35,000Freight 1,500Installation 3,000Testing 2,000Total cost $41,500Note: Personal property taxes on the machine for the period after acquisition are not part of acquisition cost. They are expensed in the period incurred.Brief Exercise 10-2Capitalized cost of land:Purchase price $600,000Broker’s commission30,000Title insurance 3,000Miscellaneous closing costs 6,000Demolition of old building 18,000Total cost $657,000All of the expenditures, including the costs to demolish the old building, are included in the initial cost of the land.Brief Exercise 10-3Cost of land and building:Purchase price $600,000Broker’s commission30,000Title insurance 3,000Miscellaneous closing costs 6,000Total cost $639,000The total must be allocated to the land and building based on their relative fair values:Brief Exercise 10-4Cost of silver mine:Acquisition, exploration, and development $5,600,000Restoration costs 429,675 †$6,029,675† $500,000 x 20% = $100,000550,000 x 45% = 247,500650,000 x 35% = 227,500$575,000 x .74726* = $429,675*Present value of $1, n = 5, i = 6% (from Table 2)Brief Exercise 10-5After one year, the liability will increase to $455,456.($429,675† + ($429,675 x 6%) = $455,456)† $500,000 x 20% = $100,000550,000 x 45% = 247,500650,000 x 35% = 227,500$575,000 x .74726* = $429,675*Present value of $1, n = 5, i = 6% (from Table 2)Actual restoration costs $596,000Less: Asset retirement liability (575,000)Loss on retirement $ (21,000)Brief Exercise 10-6Calculation of goodwill:Consideration exchanged $14,000,000 Less fair value of net assets:Book value of assets $8,300,000Plus: Excess of fair value over book valueof intangible assets 2,500,000 (10,800,000) Goodwill $ 3,200,000Brief Exercise 10-7The initial value of machinery and note will be the present value of the note payment:PV = $60,000 (.85734* ) = $51,440*P resent value of $1: n = 2, i = 8% (from Table 2)Interest expense for July 1 to December 31, 2011:$51,440 x 8% x 6/12= $2,058Brief Exercise 10-8The cost of the patent equals the fair value of the stock given in exchange: 50,000 x $22 = $1,100,000Brief Exercise 10-9Average PP&E for 2011 = ($740,000 + 940,000) ÷ 2 = $840,000Net sales ÷ Average PP&E = Fixed-asset turnover ratio? ÷ $840,000 = 3.25Average PP&E x Fixed-asset turnover ratio = Net sales$840,000 x 3.25 = $2,730,000Brief Exercise 10-10Proceeds $16,000Less book value: $80,000(71,000) 9,000Gain on sale of equipment $ 7,000Journal entry (not required):Cash ................................................................................ 16,000Accumulated depreciation (account balance) .................... 71,000Gain (difference) ........................................................... 7,000 Equipment(account balance).......................................... 80,000Brief Exercise 10-11Pickup trucks = Fair value of machinery plus cash paid$17,000 + 8,000 = $25,000Loss on exchange = $20,000 (book value) – 17,000 (fair value) = $3,000 Journal entry (not required):Pickup trucks (determined above) ..................................... 25,000Accumulated depreciation (account balance) .................... 45,000Loss (difference)................................................................ 3,000Cash ........................................................................... 8,000 Machinery(account balance).......................................... 65,000 Brief Exercise 10-12Pickup trucks = Fair value of machinery plus cash paid$24,000 + 8,000 = $32,000Gain on exchange = $24,000 (fair value) – 20,000 (book value ) = $4,000 Journal entry (not required):Pickup trucks (determined above) ..................................... 32,000Accumulated depreciation (account balance) .................... 45,000Cash ........................................................................... 8,000 Gain (difference) ........................................................... 4,000 Machinery(account balance).......................................... 65,000Brief Exercise 10-13Pickup trucks = Book value of machinery plus cash paid$20,000 + 8,000 = $28,000No gain is recognized in this situation.Journal entry (not required):Pickup trucks (determined above) ..................................... 28,000Accumulated depreciation (account balance) .................... 45,000Cash ........................................................................... 8,000 Machinery(account balance).......................................... 65,000Brief Exercise 10-14Average accumulated expenditures:January 1$500,000 x 12/12 = $ 500,000March 31 600,000 x 9/12 = 450,000June 30400,000 x 6/12 = 200,000 October 30 600,000 x 2/12 = 100,000$1,250,000 Interest capitalized:$1,250,000- 700,000 x 7% = $49,000$ 550,000 x 6.75%* = 37,125$ 86,125 = interest capitalized * Weighted-average rate of all other debt:$3,000,000 x 8% = $240,0005,000,000 x 6% = 300,000$8,000,000 $540,000$540,000= 6.75% weighted average$8,000,000Brief Exercise 10-15Average accumulated expenditures:January 1, 2011 $500,000 x 12/12 = $ 500,000March 31, 2011 600,000 x 9/12 = 450,000June 30, 2011 400,000 x 6/12 = 200,000October 30, 2011 600,000 x 2/12 = 100,000$1,250,000Interest capitalized:$1,250,000 x 6.77%* = $84,625* Weighted-average rate of all other debt:$ 700,000 x 7% = $ 49,0003,000,000 x 8% = 240,0005,000,000 x 6% = 300,000$8,700,000 $589,000$589,000= 6.77% weighted average$8,700,000Brief Exercise 10-16Research and development:Salaries $220,000Depreciation on R & D facilities and equipment 125,000Utilities and other direct costs 66,000Payment to another company 120,000Total R & D expense $531,000 Note: The patent filing and related legal costs and the costs of adapting the product to a particular customer’s needs are not included as research and development expense.EXERCISESExercise 10-1Capitalized cost of land:Purchase price $60,000Demolition of old building $4,000Less: Sale of materials (2,000) 2,000Legal fees for title investigation 2,000Total cost of land $64,000Capitalized cost of building:Construction costs $500,000Architect's fees 12,000Interest on construction loan 5,000Total cost of building $517,000Note: Property taxes on the land for the period after acquisition are not part ofacquisition cost. They are expensed in the period incurred.Exercise 10-2To record the purchase of a machine.To record prepaid insurance for the machine.Exercise 10-3Requirement 1Cost of land and building:Purchase price $4,000,000Title search and insurance 16,000Legal fees 5,000State transfer fees 4,000Total cost $4,025,000Note: The pro-rated property taxes for the period after acquisition are not included in the initial valuation of the land and building. They arerecorded instead as prepaid taxes and expensed over the related period.The total is allocated to the land and building based on their relative fair values:Assets:Land $3,018,750Building 1,006,250Land improvements:Parking lot 82,000Landscaping 40,000Exercise 10-3 (concluded)Requirement 2Cost of land:Purchase price $4,000,000Title search and insurance 16,000Legal fees 5,000State transfer fees 4,000Demolition of old building $250,000Less: Sale of materials (6,000) 244,000 Clearing and grading costs 86,000 Total cost of land $4,355,000 Land improvements:Parking lot 82,000 Landscaping 40,000Exercise 10-4Requirement 1Cost of copper mine:Mining site $1,000,000Development costs 600,000Restoration costs 303,939 †$1,903,939† $300,000 x 25% = $ 75,000400,000 x 40% = 160,000600,000 x 35% = 210,000$445,000 x .68301* = $303,939*Present value of $1, n = 4, i = 10% (from Table 2) Requirement 2Exercise 10-6Calculation of goodwill:Consideration exchanged $17,000,000 Less fair value of net assets:Assets $23,000,000Less: Liabilities assumed (9,500,000) (13,500,000) Goodwill $ 3,500,000 Exercise 10-7Calculation of goodwill:Consideration exchanged $11,000,000 Less fair value of net assets:Book value of net assets $7,800,000Plus: Fair value in excess of book value:Property, plant, and equipment 1,400,000Intangible assets 1,000,000Less: Book value in excess of fair value:Receivables (200,000) 10,000,000 Goodwill $ 1,000,000Exercise 10-8Exercise 10-9Requirement 1† Present value of note payment:PV = $25,000 (.75131* ) = $18,783*P resent value of $1: n = 3, i = 10% (from Table 2) Requirement 22011: Interest expense ($18,783 x 10%) = $1,878 2012: Interest expense [($18,783 + 1,878) x 10%] = 2,066 Requirement 32011: $25,000 – ($6,217 – 1,878) = $20,6612012: $25,000 – ($6,217 – 1,878 – 2,066) = 22,727Exercise 10-10Land:Purchase price $1,200,000Demolition and removal of old building 80,000Clearing and grading 150,000Closing costs 42,000 Total cost of land $1,472,000 Building:Architect’s fees$ 50,000Construction costs 3,250,000 Total cost of building $3,300,000 Machinery:Purchase price $860,000Freight charges 32,000Special platforms and wire installation 12,000Cost of trial runs 7,000 Total cost of machinery $911,000 Land improvements:Landscaping $45,000Sprinkler system 5,000 Fork lifts:PV = $16,000 + 70,000 (.93458* ) = $81,421 *P resent value of $1: n = 1, i = 7% (from Table 2)Prepaid insurance:$24,000Exercise 10-11To record the acquisition of land in exchange for common stock.To record the acquisition of a building through purchase and donation.Exercise 10-12Requirement 1($ in millions)Average PP&E for 2009 = ($4,043 + 4,151) ÷ 2 = $4,097Net sales ÷ Average PP&E = Fixed-asset turnover ratio$36,117 ÷ $4,097 = 8.82Requirement 2The fixed-asset turnover ratio indicates the level of sales generated by the company’s investment in fixed assets.Cisco is able to generate $8.82 in sales for every $1 invested in property, plant, and equipment.Exercise 10-13 Requirement 1Requirement 2Exercise 10-14Exercise 10-15Exercise 10-16Requirement 1Fair value of land + Cash given = F air value of equipment$150,000 + 10,000 = $160,000Requirement 2Exercise 10-17Requirement 1Fair value of land - Cash received = F air value of equipment $150,000 - 10,000 = $140,000Requirement 2Exercise 10-18Requirement 1Fair value of old land + Cash given = F air value of new land $72,000 + 14,000 = $86,000Requirement 2Requirement 3Exercise 10-191.To record the purchase of equipment on account.2.To record the acquisition of equipment in exchange for a note.PV = $27,000 (.90909* ) = $24,545*P resent value of $1: n=1, i=10% (from Table 2)3. To record the exchange of old equipment for new equipment.4. To record the acquisition of equipment by the issuance of stock.Exercise 10-20Requirement 1The Codification topic number for nonmonetary transactions is FASB ASC 845: “Nonmonetary Transactions.”Requirement 2The specific citations that describe the required disclosures for nonmonetary transactions are FASB ASC 845–10–50–1 to 2: “Nonmonetary Transactions–Overall–Disclosure.”Requirement 3An entity that engages in one or more nonmonetary transactions during a period shall disclose in financial statements for the period all of the following:a.The nature of the transactionsb.The basis of accounting for the assets transferredc.Gains or losses recognized on transfers.In accordance with paragraph 845-10-50-1, entities shall disclose, in each period's financial statements, the amount of gross operating revenue recognized as a result of nonmonetary transactions.Exercise 10-21The FASB Accounting Standards Codification represents the single source of authoritative U.S. generally accepted accounting principles. The specific citation for each of the following items is:1.The disclosure requirements in the notes to the financial statements fordepreciation on property, plant, and equipment:FASB ASC 360–10–50–1: “Property, Plant, and Equipment–Overall–Disclosure.”Because of the significant effects on financial position and results of operations of the depreciation method or methods used, all of the following disclosures shall be made in the financial statements or in notes thereto:a. Depreciation expense for the periodb. Balances of major classes of depreciable assets, by nature or function, at the balance sheet datec. Accumulated depreciation, either by major classes of depreciable assets or in total, at the balance sheet dated. A general description of the method or methods used in computing depreciation with respect to major classes of depreciable assets.Exercise 10-21 (continued)2.The criteria for determining commercial substance in a nonmonetaryexchange:FASB ASC 845–10–30–4: “Nonmonetary Transactions–Overall–Initial Measurement.”A nonmonetary exchange has commercial substance if the entity's future cashflows are expected to significantly change as a result of the exchange. The entity's future cash flows are expected to significantly change if either of the following criteria is met:a. The configuration (risk, timing, and amount) of the future cash flows of theasset(s) received differs significantly from the configuration of the future cash flows of the asset(s) transferred. The configuration of future cash flows iscomposed of the risk, timing, and amount of the cash flows. A change in any one of those elements would be a change in configuration.b. The entity-specific value of the asset(s) received differs from the entity-specific value of the asset(s) transferred, and the difference is significant inrelation to the fair values of the assets exchanged. An entity-specific value(referred to as an entity-specific measurement in FASB Concepts Statement No. 7, Using Cash Flow Information and Present Value in Accounting Measurements) is different from a fair value measurement. As described in paragraph 24(b) ofConcepts Statement No. 7, an entity-specific value attempts to capture the value of an asset or liability in the context of a particular entity. For example, an entity computing an entity-specific value of an asset would use its expectations about its use of that asset rather than the use assumed by marketplace participants. If it is determined that the transaction has commercial substance, the exchange would be measured at fair value, rather than at the entity-specific value.A qualitative assessment will, in some cases, be conclusive in determining that theestimated cash flows of the entity are expected to significantly change as a result of the exchange.Exercise 10-21 (continued)3.The disclosure requirements for interest capitalization:FASB ASC 835–20–50–1: “Interest Capitalization–Overall–Disclosure.”An entity shall disclose the following information with respect to interest cost in the financial statements or related notes:a. For an accounting period in which no interest cost is capitalized, the amount ofinterest cost incurred and charged to expense during the periodb. For an accounting period in which some interest cost is capitalized, the totalamount of interest cost incurred during the period and the amount thereof that has been capitalized.Exercise 10-21 (concluded)4.The elements of costs to be included as R&D activities:FASB ASC 730–10–25–2: “Research & Development–Overall–Recognition.”Elements of costs shall be identified with research and development activities as follows:a. Materials, equipment, and facilities. The costs of materials (whether from the entity'snormal inventory or acquired specially for research and development activities) andequipment or facilities that are acquired or constructed for research and development activities and that have alternative future uses (in research and development projects or otherwise) shall be capitalized as tangible assets when acquired or constructed. The cost of such materials consumed in research and development activities and the depreciation of such equipment or facilities used in those activities are research and development costs.However, the costs of materials, equipment, or facilities that are acquired or constructed for a particular research and development project and that have no alternative future uses (in other research and development projects or otherwise) and therefore no separateeconomic values are research and development costs at the time the costs are incurred.b. Personnel. Salaries, wages, and other related costs of personnel engaged in researchand development activities shall be included in research and development costs.c. Intangible assets purchased from others. The costs of intangible assets that arepurchased from others for use in research and development activities and that havealternative future uses (in research and development projects or otherwise) shall beaccounted for in accordance with Topic 350. The amortization of those intangible assets used in research and development activities is a research and development cost. However, the costs of intangibles that are purchased from others for a particular research anddevelopment project and that have no alternative future uses (in other research anddevelopment projects or otherwise) and therefore no separate economic values areresearch and development costs at the time the costs are incurred.d. Contract services. The costs of services performed by others in connection with theresearch and development activities of an entity, including research and development conducted by others in behalf of the entity, shall be included in research and development costs.e. Indirect costs. Research and development costs shall include a reasonable allocation ofindirect costs. However, general and administrative costs that are not clearly related to research and development activities shall not be included as research and development costs.。

《固体干燥》课件

人工干燥可以控制干燥温度、湿度和时间，干燥速度快，但需要消耗能源，成本较高。
真空干燥
真空干燥是指在真空环境中，使固体物料中的水分蒸发并逐渐干燥的方法。
真空干燥可以降低水的沸点，加快干燥速度，同时可以防止物料氧化、变质等，但需要特殊的真空设备和较高的操作技术。
微波干燥
微波干燥是指利用微波能量使固体物料中的水分迅速蒸发并逐渐干燥的方法。
在固体干燥过程中，湿分在固体内部的扩散是干燥过程的重要环节。扩散速率取决于湿分在固体中的扩散系数和浓度梯度。
相变原理
相变原理是指通过物质相变来去除湿分的原理。
在相变原理中，物质首先被加热到熔点或沸点，然后通过相变释放出所含的湿分。常见的相变干燥剂包括氯化钙、碱石灰等。
相变原理适用于大量湿分的去除，尤其在需要快速干燥的场合。然而，相变过程需要消耗大量能量，因此在实际应用中需综合考虑能耗和干燥效果。
05
固体干燥的影响因素
温度的影响
温度升高，干燥速率加快
随着温度的升高，分子热运动加快，水分子的扩散速度和蒸发速度都会增加，从而加快了干燥速率。
温度对干燥平衡的影响
温度的升高可能会导致干燥平衡的湿度值发生变化，因为温度会影响物质的吸附等温线。
湿分的影响
要点一
湿分含量越高，干燥时间越长
湿分含量越高，需要蒸发的水分越多，干燥时间就越长。
《固体干燥》课件
目录
• 固体干燥概述 • 固体干燥原理 • 固体干燥技术 • 固体干燥设备 • 固体干燥的影响因素 • 固体干燥的优化与改进 • 固体干燥的发展趋势与展望
01
固体干燥概述
定义与特点
定义
固体干燥是指通过物理或化学方法将固体物料中的水分或其他溶剂去除，使其达到所需的干燥状态的过程。

Intermediate Accounting Chapter10 课后习题答案

Chapter 10 Property, Plant, and Equipment and Intangible Assets: Acquisition and Disposition QUESTIONS FOR REVIEW OF KEY TOPICSQuestion 10-1The difference between tangible and intangible long-lived, revenue-producing assets is that intangible assets lack physical substance and they primarily refer to the ownership of rights. Question 10-2The cost of property, plant, and equipment and intangible assets includes the purchase price (less any discounts received from the seller), transportation costs paid by the buyer to transport the asset to the location in which it will be used, expenditures for installation, testing, legal fees to establish title, and any other costs of bringing the asset to its condition and location for use. Question 10-3The cost of a developed natural resource includes the acquisition costs for the use of land, the exploration and development costs incurred before production begins, and the restoration costs incurred during or at the end of extraction.Question 10-4Purchased intangibles are valued at their original cost to include the purchase price and all other necessary costs to bring the asset to condition and location for use. Research and development costs incurred to internally develop an intangible asset are expensed in the period incurred. Filing and legal costs for both purchased and developed intangibles are capitalized.Question 10-5Goodwill represents the unique value of the company as a whole over and above all identifiable tangible and intangible assets. This value results from a company’s clientele and reputation, its trained employees and management team, its unique business location, and any other unique features of the company that can’t be associated with a specific asset.Because goodwill can’t b e separated from a company, it is not possible for a buyer to acquire it without also acquiring the whole company or a substantial portion of it. Goodwill will appear as an asset in a balance sheet only when it was paid for in connection with the acquisition of another company. The capitalized cost of goodwill equals the purchase price of the acquired company less the fair value of the net assets acquired. The fair value of the net assets equals the fair value of all identifiable tangible and intangible assets less the fair value of any liabilities of the selling company assumed by the buyer.Answers to Questions (continued)Question 10-6A lump-sum purchase price generally is allocated based on the relative fair values of the individual assets. The relative fair value percentages are multiplied by the lump-sum purchase price to arrive at the initial valuation of each of the separate assets.Question 10-7Assets acquired in exchange for deferred payment contracts are valued at their fair value or the present value of payments using a realistic interest rate. Theoretically, both alternatives should lead to the same valuation.Question 10-8Assets acquired through the issuance of equity securities are valued at the fair value of the securities if known; if not known, the fair value of the assets received is used.Question 10-9Donated assets are valued at their fair values.Question 10-10When an item of property, plant, and equipment is sold, a gain or loss is recognized for the difference betwee n the consideration received and the asset’s book value. Retirements and abandonments are handled in a similar fashion. The only difference is that there will be no monetary consideration received. A loss is recorded for the remaining book value of the asset.Question 10-11The basic principle used to value assets acquired in a nonmonetary exchange is to use the fair value of asset(s) given up plus (minus) monetary consideration - cash - paid (received).Question 10-12The two exceptions are (1) when fair value is not determinable and (2) when the exchange lacks commercial substance.Question 10-13GAAP require the capitalization of interest incurred during the construction of assets for a company’s own use as well as for assets constructed for sale or lease. Assets qualifying for capitalization exclude inventories that are routinely manufactured in large quantities on a repetitive basis and assets that are in use or ready for their intended purpose. Only assets that are constructed as discrete projects qualify for interest capitalization.Answers to Questions (continued)Question 10-14Average accumulated expenditures for a period is an approximation of the average amount of debt the company would have had outstanding if it borrowed all of the funds necessary for construction. If construction expenditures are incurred equally throughout the period, the average accumulated expenditures for the period can be estimated by adding the accumulated expenditures at the beginning of the period to the accumulated expenditures at the end of the period and dividing by two. If expenditures on the project are unequal throughout the period, individual expenditures, perhaps expenditures grouped by month, should be weighted by the amount of time outstanding until the end of the construction period or the end of the company’s fiscal year, whichever comes first. Question 10-15Applying the specific interest method, the interest rate on any construction related debt is used up to the amount of the construction debt and any excess average accumulated expenditures is multiplied by a weighted-average interest rate of all other debt. The weighted-average method multiplies average accumulated expenditures by the weighted-average interest rate of all debt, including any construction-related debt.Question 10-16GAAP defines research and development as follows:Research is planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service or a new process or technique or in bringing about a significant improvement to an existing product or process.Development is the translation of research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or use.Question 10-17GAAP specifically excludes from current R&D expense the cost of property, plant, and equipment and intangible assets that have “alternative future uses” beyond the current R&D project. However, the depreciation or amortization of these assets will be included as R&D expenses in the future periods the assets are used for R&D activities. If the asset has no alternative future use, its cost is expensed as R&D immediately.Question 10-18GAAP requires the capitalization of software development costs incurred after technological feasibility is established. Technological feasibility is established “when the enterprise has completed all planning, designing, coding, and testing activities that are necessary to establish that the product can be produced to meet its design specifications including functions, features, and technical performance requirements.” Costs incurred after technological feasibility but before the product is available for general release to customers are capitalized as an intangible asset. These costs include coding and testing costs and the production of product masters. Costs incurred after commercial production begins usually are not R&D expenditures.Answers to Questions (concluded)Question 10-19The cost of developed technology is capitalized and expensed over its expected useful life. Developed technology relates to those projects that have reached technological feasibility. Before 2009, the cost of in-process R&D was expensed in the period of the acquisition. Now, the cost of in-process R&D is capitalized and treated as an indefinite life intangible asset and not amortized. If the R&D project is completed successfully, we switch to the way we account for developed technology and amortize the capitalized amount over the estimated period the product or process developed will provide benefits. If the project instead is abandoned, we expense the entire balance immediately. Research and development costs incurred after the acquisition to complete the project are expensed as incurred, consistent with the treatment of any other R&D not acquired in an acquisition. Question 10-20Other than software development costs incurred after technological feasibility has been established, U.S. GAAP requires all research and development expenditures to be expensed in the period incurred. IAS No. 38draws a distinction between research activities and development activities. Research expenditures are expensed in the period incurred. However, development expenditures that meet specified criteria are capitalized as an intangible asset.Question 10-21The periodic amortization percentage for capitalized computer software development costs under U.S. GAAP is the greater of (1) the ratio of current revenues to current and anticipated revenues or (2) the straight-line percentage over the useful life of the software. This approach is allowed under IFRS, but not required.Question 10-22The successful efforts method allows companies to capitalize only exploration costs resulting in successful wells. The full-cost method allows companies to capitalize all exploration costs incurred within a geographical area.BRIEF EXERCISESBrief Exercise 10-1Capitalized cost of the machine:Purchase price $35,000Freight 1,500Installation 3,000Testing 2,000Total cost $41,500Note: Personal property taxes on the machine for the period after acquisition are not part of acquisition cost. They are expensed in the period incurred.Brief Exercise 10-2Capitalized cost of land:Purchase price $600,000Broker’s commission30,000Title insurance 3,000Miscellaneous closing costs 6,000Demolition of old building 18,000Total cost $657,000All of the expenditures, including the costs to demolish the old building, are included in the initial cost of the land.Brief Exercise 10-3Cost of land and building:Purchase price $600,000Broker’s commission30,000Title insurance 3,000Miscellaneous closing costs 6,000Total cost $639,000The total must be allocated to the land and building based on their relative fair values:Brief Exercise 10-4Cost of silver mine:Acquisition, exploration, and development $5,600,000Restoration costs 429,675 †$6,029,675† $500,000 x 20% = $100,000550,000 x 45% = 247,500650,000 x 35% = 227,500$575,000 x .74726* = $429,675*Present value of $1, n = 5, i = 6% (from Table 2)Brief Exercise 10-5After one year, the liability will increase to $455,456.($429,675† + ($429,675 x 6%) = $455,456)† $500,000 x 20% = $100,000550,000 x 45% = 247,500650,000 x 35% = 227,500$575,000 x .74726* = $429,675*Present value of $1, n = 5, i = 6% (from Table 2)Actual restoration costs $596,000Less: Asset retirement liability (575,000)Loss on retirement $ (21,000)Brief Exercise 10-6Calculation of goodwill:Consideration exchanged $14,000,000 Less fair value of net assets:Book value of assets $8,300,000Plus: Excess of fair value over book valueof intangible assets 2,500,000 (10,800,000) Goodwill $ 3,200,000Brief Exercise 10-7The initial value of machinery and note will be the present value of the note payment:PV = $60,000 (.85734* ) = $51,440*P resent value of $1: n = 2, i = 8% (from Table 2)Interest expense for July 1 to December 31, 2011:$51,440 x 8% x 6/12= $2,058Brief Exercise 10-8The cost of the patent equals the fair value of the stock given in exchange: 50,000 x $22 = $1,100,000Brief Exercise 10-9Average PP&E for 2011 = ($740,000 + 940,000) ÷ 2 = $840,000Net sales ÷ Average PP&E = Fixed-asset turnover ratio? ÷ $840,000 = 3.25Average PP&E x Fixed-asset turnover ratio = Net sales$840,000 x 3.25 = $2,730,000Brief Exercise 10-10Proceeds $16,000Less book value: $80,000(71,000) 9,000Gain on sale of equipment $ 7,000Journal entry (not required):Cash ................................................................................ 16,000Accumulated depreciation (account balance) .................... 71,000Gain (difference) ........................................................... 7,000 Equipment(account balance).......................................... 80,000Brief Exercise 10-11Pickup trucks = Fair value of machinery plus cash paid$17,000 + 8,000 = $25,000Loss on exchange = $20,000 (book value) – 17,000 (fair value) = $3,000 Journal entry (not required):Pickup trucks (determined above) ..................................... 25,000Accumulated depreciation (account balance) .................... 45,000Loss (difference)................................................................ 3,000Cash ........................................................................... 8,000 Machinery(account balance).......................................... 65,000 Brief Exercise 10-12Pickup trucks = Fair value of machinery plus cash paid$24,000 + 8,000 = $32,000Gain on exchange = $24,000 (fair value) – 20,000 (book value ) = $4,000 Journal entry (not required):Pickup trucks (determined above) ..................................... 32,000Accumulated depreciation (account balance) .................... 45,000Cash ........................................................................... 8,000 Gain (difference) ........................................................... 4,000 Machinery(account balance).......................................... 65,000Brief Exercise 10-13Pickup trucks = Book value of machinery plus cash paid$20,000 + 8,000 = $28,000No gain is recognized in this situation.Journal entry (not required):Pickup trucks (determined above) ..................................... 28,000Accumulated depreciation (account balance) .................... 45,000Cash ........................................................................... 8,000 Machinery(account balance).......................................... 65,000Brief Exercise 10-14Average accumulated expenditures:January 1$500,000 x 12/12 = $ 500,000March 31 600,000 x 9/12 = 450,000June 30400,000 x 6/12 = 200,000 October 30 600,000 x 2/12 = 100,000$1,250,000 Interest capitalized:$1,250,000- 700,000 x 7% = $49,000$ 550,000 x 6.75%* = 37,125$ 86,125 = interest capitalized * Weighted-average rate of all other debt:$3,000,000 x 8% = $240,0005,000,000 x 6% = 300,000$8,000,000 $540,000$540,000= 6.75% weighted average$8,000,000Brief Exercise 10-15Average accumulated expenditures:January 1, 2011 $500,000 x 12/12 = $ 500,000March 31, 2011 600,000 x 9/12 = 450,000June 30, 2011 400,000 x 6/12 = 200,000October 30, 2011 600,000 x 2/12 = 100,000$1,250,000Interest capitalized:$1,250,000 x 6.77%* = $84,625* Weighted-average rate of all other debt:$ 700,000 x 7% = $ 49,0003,000,000 x 8% = 240,0005,000,000 x 6% = 300,000$8,700,000 $589,000$589,000= 6.77% weighted average$8,700,000Brief Exercise 10-16Research and development:Salaries $220,000Depreciation on R & D facilities and equipment 125,000Utilities and other direct costs 66,000Payment to another company 120,000Total R & D expense $531,000 Note: The patent filing and related legal costs and the costs of adapting the product to a particular customer’s needs are not included as research and development expense.EXERCISESExercise 10-1Capitalized cost of land:Purchase price $60,000Demolition of old building $4,000Less: Sale of materials (2,000) 2,000Legal fees for title investigation 2,000Total cost of land $64,000Capitalized cost of building:Construction costs $500,000Architect's fees 12,000Interest on construction loan 5,000Total cost of building $517,000Note: Property taxes on the land for the period after acquisition are not part ofacquisition cost. They are expensed in the period incurred.Exercise 10-2To record the purchase of a machine.To record prepaid insurance for the machine.Exercise 10-3Requirement 1Cost of land and building:Purchase price $4,000,000Title search and insurance 16,000Legal fees 5,000State transfer fees 4,000Total cost $4,025,000Note: The pro-rated property taxes for the period after acquisition are not included in the initial valuation of the land and building. They arerecorded instead as prepaid taxes and expensed over the related period.The total is allocated to the land and building based on their relative fair values:Assets:Land $3,018,750Building 1,006,250Land improvements:Parking lot 82,000Landscaping 40,000Exercise 10-3 (concluded)Requirement 2Cost of land:Purchase price $4,000,000Title search and insurance 16,000Legal fees 5,000State transfer fees 4,000Demolition of old building $250,000Less: Sale of materials (6,000) 244,000 Clearing and grading costs 86,000 Total cost of land $4,355,000 Land improvements:Parking lot 82,000 Landscaping 40,000Exercise 10-4Requirement 1Cost of copper mine:Mining site $1,000,000Development costs 600,000Restoration costs 303,939 †$1,903,939† $300,000 x 25% = $ 75,000400,000 x 40% = 160,000600,000 x 35% = 210,000$445,000 x .68301* = $303,939*Present value of $1, n = 4, i = 10% (from Table 2) Requirement 2Exercise 10-6Calculation of goodwill:Consideration exchanged $17,000,000 Less fair value of net assets:Assets $23,000,000Less: Liabilities assumed (9,500,000) (13,500,000) Goodwill $ 3,500,000 Exercise 10-7Calculation of goodwill:Consideration exchanged $11,000,000 Less fair value of net assets:Book value of net assets $7,800,000Plus: Fair value in excess of book value:Property, plant, and equipment 1,400,000Intangible assets 1,000,000Less: Book value in excess of fair value:Receivables (200,000) 10,000,000 Goodwill $ 1,000,000Exercise 10-8Exercise 10-9Requirement 1† Present value of note payment:PV = $25,000 (.75131* ) = $18,783*P resent value of $1: n = 3, i = 10% (from Table 2) Requirement 22011: Interest expense ($18,783 x 10%) = $1,878 2012: Interest expense [($18,783 + 1,878) x 10%] = 2,066 Requirement 32011: $25,000 – ($6,217 – 1,878) = $20,6612012: $25,000 – ($6,217 – 1,878 – 2,066) = 22,727Exercise 10-10Land:Purchase price $1,200,000Demolition and removal of old building 80,000Clearing and grading 150,000Closing costs 42,000 Total cost of land $1,472,000 Building:Architect’s fees$ 50,000Construction costs 3,250,000 Total cost of building $3,300,000 Machinery:Purchase price $860,000Freight charges 32,000Special platforms and wire installation 12,000Cost of trial runs 7,000 Total cost of machinery $911,000 Land improvements:Landscaping $45,000Sprinkler system 5,000 Fork lifts:PV = $16,000 + 70,000 (.93458* ) = $81,421 *P resent value of $1: n = 1, i = 7% (from Table 2)Prepaid insurance:$24,000Exercise 10-11To record the acquisition of land in exchange for common stock.To record the acquisition of a building through purchase and donation.Exercise 10-12Requirement 1($ in millions)Average PP&E for 2009 = ($4,043 + 4,151) ÷ 2 = $4,097Net sales ÷ Average PP&E = Fixed-asset turnover ratio$36,117 ÷ $4,097 = 8.82Requirement 2The fixed-asset turnover ratio indicates the level of sales generated by the company’s investment in fixed assets.Cisco is able to generate $8.82 in sales for every $1 invested in property, plant, and equipment.Exercise 10-13 Requirement 1Requirement 2Exercise 10-14Exercise 10-15Exercise 10-16Requirement 1Fair value of land + Cash given = F air value of equipment$150,000 + 10,000 = $160,000Requirement 2Exercise 10-17Requirement 1Fair value of land - Cash received = F air value of equipment $150,000 - 10,000 = $140,000Requirement 2Exercise 10-18Requirement 1Fair value of old land + Cash given = F air value of new land $72,000 + 14,000 = $86,000Requirement 2Requirement 3Exercise 10-191.To record the purchase of equipment on account.2.To record the acquisition of equipment in exchange for a note.PV = $27,000 (.90909* ) = $24,545*P resent value of $1: n=1, i=10% (from Table 2)3. To record the exchange of old equipment for new equipment.4. To record the acquisition of equipment by the issuance of stock.Exercise 10-20Requirement 1The Codification topic number for nonmonetary transactions is FASB ASC 845: “Nonmonetary Transactions.”Requirement 2The specific citations that describe the required disclosures for nonmonetary transactions are FASB ASC 845–10–50–1 to 2: “Nonmonetary Transactions–Overall–Disclosure.”Requirement 3An entity that engages in one or more nonmonetary transactions during a period shall disclose in financial statements for the period all of the following:a.The nature of the transactionsb.The basis of accounting for the assets transferredc.Gains or losses recognized on transfers.In accordance with paragraph 845-10-50-1, entities shall disclose, in each period's financial statements, the amount of gross operating revenue recognized as a result of nonmonetary transactions.Exercise 10-21The FASB Accounting Standards Codification represents the single source of authoritative U.S. generally accepted accounting principles. The specific citation for each of the following items is:1.The disclosure requirements in the notes to the financial statements fordepreciation on property, plant, and equipment:FASB ASC 360–10–50–1: “Property, Plant, and Equipment–Overall–Disclosure.”Because of the significant effects on financial position and results of operations of the depreciation method or methods used, all of the following disclosures shall be made in the financial statements or in notes thereto:a. Depreciation expense for the periodb. Balances of major classes of depreciable assets, by nature or function, at the balance sheet datec. Accumulated depreciation, either by major classes of depreciable assets or in total, at the balance sheet dated. A general description of the method or methods used in computing depreciation with respect to major classes of depreciable assets.Exercise 10-21 (continued)2.The criteria for determining commercial substance in a nonmonetaryexchange:FASB ASC 845–10–30–4: “Nonmonetary Transactions–Overall–Initial Measurement.”A nonmonetary exchange has commercial substance if the entity's future cashflows are expected to significantly change as a result of the exchange. The entity's future cash flows are expected to significantly change if either of the following criteria is met:a. The configuration (risk, timing, and amount) of the future cash flows of theasset(s) received differs significantly from the configuration of the future cash flows of the asset(s) transferred. The configuration of future cash flows iscomposed of the risk, timing, and amount of the cash flows. A change in any one of those elements would be a change in configuration.b. The entity-specific value of the asset(s) received differs from the entity-specific value of the asset(s) transferred, and the difference is significant inrelation to the fair values of the assets exchanged. An entity-specific value(referred to as an entity-specific measurement in FASB Concepts Statement No. 7, Using Cash Flow Information and Present Value in Accounting Measurements) is different from a fair value measurement. As described in paragraph 24(b) ofConcepts Statement No. 7, an entity-specific value attempts to capture the value of an asset or liability in the context of a particular entity. For example, an entity computing an entity-specific value of an asset would use its expectations about its use of that asset rather than the use assumed by marketplace participants. If it is determined that the transaction has commercial substance, the exchange would be measured at fair value, rather than at the entity-specific value.A qualitative assessment will, in some cases, be conclusive in determining that theestimated cash flows of the entity are expected to significantly change as a result of the exchange.Exercise 10-21 (continued)3.The disclosure requirements for interest capitalization:FASB ASC 835–20–50–1: “Interest Capitalization–Overall–Disclosure.”An entity shall disclose the following information with respect to interest cost in the financial statements or related notes:a. For an accounting period in which no interest cost is capitalized, the amount ofinterest cost incurred and charged to expense during the periodb. For an accounting period in which some interest cost is capitalized, the totalamount of interest cost incurred during the period and the amount thereof that has been capitalized.Exercise 10-21 (concluded)4.The elements of costs to be included as R&D activities:FASB ASC 730–10–25–2: “Research & Development–Overall–Recognition.”Elements of costs shall be identified with research and development activities as follows:a. Materials, equipment, and facilities. The costs of materials (whether from the entity'snormal inventory or acquired specially for research and development activities) andequipment or facilities that are acquired or constructed for research and development activities and that have alternative future uses (in research and development projects or otherwise) shall be capitalized as tangible assets when acquired or constructed. The cost of such materials consumed in research and development activities and the depreciation of such equipment or facilities used in those activities are research and development costs.However, the costs of materials, equipment, or facilities that are acquired or constructed for a particular research and development project and that have no alternative future uses (in other research and development projects or otherwise) and therefore no separateeconomic values are research and development costs at the time the costs are incurred.b. Personnel. Salaries, wages, and other related costs of personnel engaged in researchand development activities shall be included in research and development costs.c. Intangible assets purchased from others. The costs of intangible assets that arepurchased from others for use in research and development activities and that havealternative future uses (in research and development projects or otherwise) shall beaccounted for in accordance with Topic 350. The amortization of those intangible assets used in research and development activities is a research and development cost. However, the costs of intangibles that are purchased from others for a particular research anddevelopment project and that have no alternative future uses (in other research anddevelopment projects or otherwise) and therefore no separate economic values areresearch and development costs at the time the costs are incurred.d. Contract services. The costs of services performed by others in connection with theresearch and development activities of an entity, including research and development conducted by others in behalf of the entity, shall be included in research and development costs.e. Indirect costs. Research and development costs shall include a reasonable allocation ofindirect costs. However, general and administrative costs that are not clearly related to research and development activities shall not be included as research and development costs.。

化工原理7固体干燥

化工原理7：固体干燥1. 简介固体干燥是化工过程中常用的一种技术，在许多行业中都有广泛的应用。

固体干燥的目的是去除固体材料中的水分或其他溶剂，以提高其保存性、稳定性和使用性能。

本文将介绍固体干燥的原理、常用的干燥方法以及干燥过程中需要注意的问题。

2. 固体干燥的原理固体干燥的原理是基于蒸发的原理，即将液体中的水分或溶剂蒸发掉，使固体材料中的水分含量降低。

固体干燥的过程中主要发生三个阶段的变化：加热阶段、干燥阶段和冷却阶段。

加热阶段：在这个阶段，固体材料被暴露在高温环境中，使其表面的水分开始蒸发。

同时，固体材料内部的水分也会通过温度梯度的传导逐渐向表面迁移。

干燥阶段：在加热阶段之后，固体材料的表面水分已经蒸发光了，此时需要继续加热，使固体内部的水分逐渐排出。

这个阶段需要维持一个适当的温度和湿度条件。

冷却阶段：在固体材料的内部水分排除后，需要将温度逐渐降低，使固体完全干燥。

冷却阶段也是干燥过程中的最后一个阶段。

3. 常用的固体干燥方法固体干燥有许多不同的方法，下面介绍几种常见的固体干燥方法：3.1 自然干燥自然干燥是最简单直接的干燥方法之一，它利用自然环境中的风力和阳光将固体材料中的水分蒸发掉。

自然干燥的优点是成本低廉，但缺点是速度较慢，无法控制干燥的速度和温度。

3.2 通风干燥通风干燥是通过将空气吹入干燥室，利用空气中的热量和携带的湿度将固体材料中的水分蒸发掉。

通风干燥的优点是干燥速度较快，可以通过控制风速和温度来控制干燥的速度和效果。

3.3 热空气干燥热空气干燥是将热空气通过固体材料中，以提高固体材料表面的温度，从而使水分蒸发。

热空气干燥的优点是速度快，可以精确控制干燥速度和温度，缺点是需要大量的能源。

3.4 微波干燥微波干燥是将微波辐射传递到固体材料中，利用微波辐射的加热效应使固体材料中的水分蒸发。

微波干燥的优点是速度快，能耗低，但需要对固体材料的形状和尺寸进行适当的调整。

4. 注意事项在进行固体干燥过程中，需要注意以下几点：•确定干燥的目标，即需要达到的水分含量或溶剂含量。

固体干燥操作

【例7-1】已知湿空气的总压为101.3kPa，相对湿度为 70%，干球温度为20℃。试求：（1）湿度H；（2）水蒸气分压pw；（3）露点td；（4）焓I；（5）如每小时将 100kg绝干空气预热到97℃进入干燥器，求单位时间所需热量Q；（6）每小时送入预热器的湿空气体积V。
解：已知p＝101.3 kPa，φ ＝70%，t＝20℃。由饱和水蒸气表查得，水在 20℃时的饱和蒸气压ps＝2.32 kPa。（1）湿度 H 0.622 ps 0.622 0.70 2.32 0.0102 kg水/kg绝干空气
（5）预热绝干空气及其所带水蒸气所需的热量
Q 100 (1.01 1.88 0.0102)(97 20) ＝7925kJ/h ＝2.20kW
（6）湿空气体积 273 20 ＝84.3m3/h V 100H 100 (0.773 1.244 0.0102) 273
pd Hp 0.622 H
计算得到pd，查其相对应的饱和温度，即为该湿含量H和总压p时的露点td。同理，由露点td和总压p，可确定湿度H。
（3）绝热饱和温度tas 绝热饱和过程中，气、液两相最终达到的平衡温度称为绝热饱和温度。
绝热饱和器
空气
水
不饱和湿空气： t＞tW（= tas）＞td 饱和湿空气： t = tW （= tas） = td
（2）干基含水量X 湿物料中水分的质量 kg水/kg绝干物料 X 湿物料中绝对干料的质量两种表示方法的关系
w X 1 X
X w 1 w
用干基含水量计算更方便。
2．水分蒸发量W
单位时间内从湿物料中除去水分的质量，W，kg/h
在干燥前后，物料中绝干物料量不会变。

固体物料的干燥PPT(化工原理)

应用实例
介绍固体物料干燥技术在化工、食品、制药等领域的应用实例，如活性炭的制备、食品添加剂的干燥等，说明干燥技术在工业生产中的重要性和实际应用价值。
05
固体物料的干燥工业应用与发展趋势
固体物料的干燥在各行业的应用现状
农业
谷物、种子、果蔬等农产品的干燥，确保食品
质量和延长保质期。
制药
中药材、原料药、药片的干燥，确保药品质量
发展多种形式的干燥技术，满足不同物料和工艺的干燥需求
。
环保要求
严格控制干燥过程中的环境污染，实现绿色生产。
未来干燥技术的研究方向与展望
新材料在干燥技术中的应用
热泵干燥技术的研究
探索新型材料在干燥过程中的作用和应用前景。
研究热泵干燥技术的原理和应用，提高能源利用效率。
微波与远红外干燥技术的研究
02
干燥技术与方法
自然晾干
优点
简单易行，成本低，不需特殊设备。
缺点
干燥时间长，受天气和环境影响较大，不适用于大量物料的干燥。
热风干燥
优点
干燥效率高，适用于大量物料的干燥。
缺点
能源消耗较大，干燥过程中可能会对物料产生一定的热损伤。
红外线干燥
优点
干燥效率高，对物料损伤小，适用于敏感物料的干燥。
缺点
实验步骤
准备实验器材和物料、搭建实验装置、测量湿空气参数、开始干燥实验、记录数据、结束实验、清理现场。
要点二
实验操作
将待干燥物料置于干燥器内，加热空气至一定温度和湿度，通过湿空气与物料的热湿交换，使物料中的水分蒸发并随空气排出。操作过程中需注意控制干燥温度、湿度和空气流量等参数。
实验结果与数据分析

化工原理之固体物料的干燥培训课件.pptx

D
B
C
A
td
t
湿球温度：湿球温度计。
气流吹过——湿份气化——表面降温——热量传递 Q hA(t tW ) wrw
w kH (Hw H)A
稳态时，空气传入的显热等于水的汽化潜热。
补充液，温度 tw
A(
w
tW
t
kH rW h
(HW
H)
注意：湿球温度不是状态函数。
空气湿度 H 温度 t
湿球温度计的原理
② 应用
h 绝k热H饱近和似温为度常，数故（可=以0.用96其~1确.00应5空）气，状数态值。上等于相同条件下的
说明：测量湿球温度时，空气速度一般需大于5 m/s，使测量
较为精确。
（8）露点td 保持空气的H不变，降低温度，使其达到饱和状态时的温度。
H 0.622
c ( t t ) ( H H )r
H
as
as
as
空气
tas、Has
r
t t as ( H H )
as
c
as
H
② 绝热饱和温度是状态函数
t、H
空气补充水
tas f (t, H )
③ 绝热饱和过程可当作等焓处理
绝热饱和塔示意图
即空气的入口焓近似等于空气的出口焓。
（7）干、湿球温度 ① 干球温度与湿球温度干球温度：普通温度计测出的空气温度；
热量传递：由气相到固相，以温度差为推动力。
8.1.2 干燥过程的分类
常压干燥操作压力真空干燥
热空气
物料
t
间歇干燥操作方式
连续干燥
传导干燥
加热方式
对流干燥辐射干燥
湿 θi

固体干燥

三、湿空气的比容湿空气的比容（简称湿比容）:为单位质量的干空气及其所带水汽的总体积，以符号VH 表示。令Va 、Vw 分别代表干空气、水汽在总压p=101.3kPa 及温度t下的体积，则
. t . t VH Va Vw H ( ) H ( ) t ( . . ) ( H ) ( . . H ) ( t )
比较对H和t相同的湿空气：tw=tas
对其它物系， /kHcpH ，则不存在此关系。在绝热情况下，只要物料表面湿润，则其表面温度既为湿球温度。
2. 露点td
空气在湿含量不变的情况下冷却，达到饱和状态时的温度称为露点td。此时，开始有水珠冷凝出来，对应的饱和蒸汽压为pd。 pd H p H 0.622 或 pd p pd 0.622 H 故p一定时，由H可计算pd，相应的露点pd也确定了。反之，若td和总压p一定，则空气湿含量H也就确定了，故露点也为参数之一。
p水汽 0.622 p p水汽
3、空气的相对湿度 p水汽和H未能反映湿空气继续接受水分的能力。含有最大水汽量的空气，称为饱和空气，其分压为 ps 。为了表示距离饱和状态的程度，常用相对湿度φ来表示。 p水汽或 p水汽 =φ×ps
ps
讨论：（1）φ的大小的影响 φ愈小，则pw与 ps 的差距愈大，空气中的湿含量与饱和状态相距也愈远，φ＝1，空气以被水饱和，不能作为载湿体。 p水汽 ps 0.622 （2）H和φ的关系 H 0.622
四、干燥的本质及条件 1、干燥的本质被除去的湿分从固相移到气相中，固相为被干燥的物料，气相为干燥介质。 2、干燥的条件湿分在物料表面的蒸气压必须大于干燥介质（例如空气）中的蒸气分压，使得物料表面的湿分能够汽化，正是由于湿分的不断汽化，物料内部的湿分方可继续向表面移动。

固体干燥课后习题答案

第 10 章固体干燥60 C,湿球温度为30 C,试计算空气的湿含量 H ,，焓 I 和露点温度1) 已知空气的干燥温度为相对湿度解：查表得t w 300C 时P s,t w 4.247kPaH s,t w 0.622P S/(p P s) 0.0272H H s,t w[(t t w)/r tw]( /K Hh)300C 时r tw 2427 /K H 1.09H 0.0137t 600C p s 19.923kPa由H 0.0137求得此时p 2.18kPap/P s 1100I (1.01 1.88 0.0158) 60 2490 0.015896.44kJ / kg干空气由p s2.18kPa,查表得t18.40Ct d18.40C2 )利用湿空气的I—H图完成本题附表空格项的数值，湿空气的总压3 ) 湿空气 (=20 C ,)经预热后送入常压干燥器。

试求：① 将空气预热到100 C所需热量：②将该空气预热到120 C时相应的相对湿度值。

解：1）比热C H 1.01 1.88H 1.01 1.88H 0.22kJ/（KG 绝干气°C）Q C H t 80C H 83.8kJ/（kg绝干气°C）2）1200C时p s 198.64kPa 101.3kPa, H 0.02kg水/kg干气H 0.662 p s/（p P s）解得 3.12004）湿度为的湿空气在预热器中加热到128 C 后进入常压等焓干燥器中，离开干燥器时空气的温度为49 C,求离开干燥器时露点温度。

解：I = (1.01+1.88H)t + 2500H•••等焓二 h = I 2 •••(1.01+1.88H " + 2500H , = (1.01+1.88H 2)t 2 + 2500H 2 (1.01+1.88 0.018)128 + 2500 0.018= (1.01+1.88H 2)49 +2500H 2••• H 2 = 0.0498 kg 水/kg 干气p = 7510 Pa查表得 t d = 40 C5）在一定总压下空气通过升温或一定温度下空气温度通过减压来降低相对湿度，现有温度为40C,相对湿度为70%的空气。

固体干燥原理

固体干燥原理
固体干燥原理是指通过一系列的物理和化学过程将液体或潮湿的固体转化为干燥的固体。

固体干燥的过程可以通过以下几个步骤来实现：
1. 蒸发：当潮湿的固体加热时，固体表面的水分开始蒸发。

这是因为加热能够增加水分的分子动能，使其逃离固体表面形成蒸汽。

2. 扩散：一旦固体表面产生了水蒸汽，它会向空气中扩散。

扩散是水分分子沿着浓度梯度从高浓度区域向低浓度区域移动的过程。

3. 对流：干燥过程中的对流也起着重要的作用。

当空气与固体表面接触时，它会带走水蒸汽，并将其带到相对湿度较低的区域。

这种对流可以加快水分分子从固体表面脱附的速度。

4. 吸附：一旦水分分子进入空气中，它们会与空气中的水分子发生吸附作用。

吸附是指水分分子与空气分子之间的相互作用力，使水分分子停留在空气中而不重新被固体吸收。

通过将上述步骤结合起来应用，固体干燥的原理就能够实现。

在实际应用中，常见的固体干燥方法包括热风干燥、真空干燥、冷冻干燥等，它们都是基于这些原理来进行的。

这些方法在工业生产、食品加工、制药等领域得到了广泛应用，能够有效地将潮湿的固体转化为干燥的固体，提高产品的质量和保存期限。

10固体干燥

10.2 湿空气的性质及湿焓图南京工业大学
南京工业大学
饱和湿度Hs 若pw=ps (空气温度下水的饱和蒸汽压) ，则湿空气呈饱和状态。 Hs=0.622 ps/(P-ps) 其中ps=ps (tபைடு நூலகம் logps=A-B/(t+C) 所以HS=HS(P,t)
南京工业大学
(2). 相对湿度φ 定义：φ=pw/ps 衡量湿空气的不饱和程度， t↑ →ps↑ →φ↓ 若 φ=100﹪ 湿空气达饱和状态，无干燥能力；φ<100﹪的不饱和空气才能作为干燥介质。φ值越小，干燥能力越大。
南京工业大学
H和φ的比较：区别：H表示水汽在湿空气中的绝对含量; φ反映出湿空气吸收水分的能力联系：H=0.622 pw/(P-pw) = 0.622 φps/(P-φps) 由P，t，H可求得φ 特例： (pS )max＝P (当pS >P ) φ=p /P
2．比容（湿容积，比体积）
5
273 t 1.013 10 vH (0.772 1.244 H ) 273 P
南京工业大学
3．比热（湿热）
定义：将1㎏绝干气和其中的H㎏水蒸气的湿度升高或降低1℃所吸收或放出的热量。表达式： cH=ca+HcV =1.01+1.88H kJ/(kg绝干气.℃)
南京工业大学
④对流干燥
南京工业大学
定义：热能以对流给热的方式由热干燥介质(通常是热空气)传给湿物料，使物料中的水分汽化，物料内部的水分以气态或液态形式扩散至物料表面，然后汽化的蒸汽从表面扩散至干燥介质主体，再由介质带走的干燥过程，称为～。
④对流干燥
南京工业大学
特征：传热和传质同时发生，干燥介质既是热载体，又是湿载体。干燥过程对干燥介质是降温增湿过程。干燥器种类:气流干燥器、流化床、喷雾干燥器。热介质种类：热空气、烟道气、其他高温气体。讨论：以热空气为干燥介质的对流干燥最为普遍，本章着重讨论该干燥过程（以 H2O去除为主）

固体物料的干燥PPT(化工原理

H m3绝k干 g绝气干m＋ 3气水汽mk3g绝绝干干气气 kmg绝 3水干汽气
mk3g绝绝干干气气 kmg绝 3水干汽气 kk gg水水汽汽
H g HV
常压下
g2 2.4 2 92 27 7 t 3 2 3 .8 3 1 3 0 27 t3
V2 1 .4 2 8 1 2 2 7 7 t 3 4 3 .5 1 6 3 0 2 7 t3
所以： HgH V
(2.8 310 34.5 610 3H )2 ( 7 t3 )
Hf(t， H)
5.比热容〔湿热〕cpH
• 定义：在常压下，将1kg绝干空气及相应Hkg水汽升高(或降低) 1℃所需吸收(或放出)的热量， kJ/(kg绝干气•℃)。
cpH cp gcpH v 1 .0 1 .8H 8
• tw ：大量空气与少量水接触，空气的t、H不变； tas ：大量水与一定量空气接触，空气降温、增湿。
tw ：是传热与传质速率均衡的结果，属于动平衡； • tas ：是由热量衡算与物料衡算导出的，属于静平衡。
• tw 与 tas 数值上的差异取决于α/kH 与cH两者之间的差异。
❖ 空气—水体系， ❖ 空气—甲苯体系，
温度为 t、水汽分压为 pv 的湿热气体流过湿物料的外表，物料外表温度θi低于气体温度 t。
由于温差的存在，气体以对流方式向固体物料传热，使水分汽化；
在分压差的作用下，水汽由物料
H
外表向气流主体扩散，并被气流带
t
走。特点
θi
q
1. 传热、传质同时进展，传递方 2. 向相反;
pi
W
M
pv
方向推动力
cH=f(H)
6.湿空气的焓I

固体干燥--ws

tw A
t
Φ=100%
空气状态的确定
已知t、td t
td A
Φ=100%
空气状态的确定
已知t、φ
t
A
Φ Φ=100%
湿物料中含水量的表示方法湿基含水量w：
w=湿物料中水分的质量/湿物料的总质量 kg水/kg湿物料干基含水量X: X=湿物料中水分的质量/湿物料中绝干物料的质量 kg水/kg绝干料
湿空气的性质
2．相对湿度φ 定义φ=p/ps 衡量湿空气的不饱和程度， t↑ →ps↑ →φ↓ 若 φ=100﹪ 湿空气达饱和状态，无干燥能力；φ<100﹪的不饱和空气才能作为干燥介质。φ值越小，干燥能力越大。
湿空气的性质
H和φ的比较：区别：H表示水汽在湿空气中的绝对含量; φ反映出湿空气吸收水分的能力联系：H=0.622 pw/(P-pw) = 0.622 φps/(P-φps) 由P，t，H可求得φ
湿空气的性质
∵I1=I2 ∴ cHt+Hr0＝ cHtas +Hasr0 ∴tas=t-r0(Has-H)/cH tas=tas(t,H) 与tw=t-(kHrw/α)(HS,W-H)比较: 当空气流速较高时 r0≈rw Has≈HS,W cH≈α/kH →tas=tw
湿空气的性质
9．露点td 将不饱和的空气等湿冷却至饱和状态（φ=100﹪）此时的温度称为该空气的露点，以td表示。露点时 Hs,td=0.622ps,td/(P- ps,td)
L,H0 L,H1
预热器
GC,X2
干燥器
L,H2
GC,X1
物料衡算
绝干空气流量: L=W/(H2-H1)
kg绝干气/s

生物制药设备管理概述

3.2 喷雾干燥设备离心喷雾干燥：
离心喷盘：喷枪式喷盘锥形喷盘圆帽式喷盘
❖ 喷枪式喷盘：
由一组喷嘴（一般为6个）伸在离心盘外，如同翼轮一样。但中心形成负压，被喷物料容易卷起，粘在顶壁上。
锥形和圆帽形可避免这一不足，后两种形式较好。锥形喷盘：是一组喷嘴装在离心盘内，避免中心形成负压圆帽式喷盘：其喷孔出口向下倾斜45°，避免被喷物料向上翻。
第一节固体物料干燥机理及生物工业产品干燥的特点喷雾干燥器
1 固体物料干燥机理及生物工业产品干燥的特点
一、固体物料的干燥机理 1.物料中水分的性质
❖ 游离水 ❖ 结合水哪一种容易干燥呢？平衡水分：达到平衡时物料或空气中的水分。
1 固体物料干燥机理及生物工业产品干燥的特点
一、固体物料的干燥机理
特点：旋风式气流干燥器没有长管式那样的长管，因此不需要高层的厂房，操作也较简便。
3.1 气流干燥设备
旋风式干燥器流程图
旋风式气流干燥管
3.2 喷雾干燥设备
（一）原理和特点 ❖ 喷雾器将原料喷成雾状，与热空气发生热量和质
量传递的干燥过程 ❖ 特点：干燥速度快、干燥温度较低、产品分散性
和溶解性良好
2.1 非绝热干燥设备
一、单层麦芽干燥塔 1.结构与操作 ②操作工艺参数： ❖ 前期：恒速，42-46↓10%
干燥温度＜55℃
❖ 后期：降速，10%↓3-3.5%
干燥温度约为85℃
2特点
优点：产量高，麦层高，能耗小，结构简单缺点：不能搅拌水分滞后，3-4h 温度滞后
单层水平式流化干燥塔
① 不向干燥器补充热量，物料进出干燥器的焓差发生了明显的改变。 ② 向干燥器补充的热量比热损失及物料带走的热量之和还要大。 ③ 向干燥器中补充的热量足够大，能够使干燥过程在等温下进行，但进出干燥器物料的焓发生了明显的改变。