高效高块率采煤机螺旋滚筒技术改造

煤矿机电
高效高块率采煤机螺旋滚筒技术改造
邱光林1,梁安文2
(11晋城煤业集团,山西晋城048006;21潞安矿业集团,山西长治046204)
[摘　要]　从提高煤炭产品块率和装载效率的目的出发,结合晋城矿区的煤层开采特征,对采
煤机螺旋滚筒的截齿、滚筒结构、工艺措施等几个技术改造的关键部分进行了分析。

[关键词]　块率;截齿;滚筒结构;工艺措施
[中图分类号]T D42116+1 [文献标识码]A [文章编号]100626225(2001)0320075203
[收稿日期]2001-04-11
[作者简介]邱光林(1965-),工程师,1988年毕业于山西矿业学院采煤工程系,现任煤业集团劳动服务总公司川底矿矿长。

晋城煤业集团现有古书院矿、王台铺矿、凤凰
山矿、成庄矿4对生产矿井和寺河矿一对建设矿井,设计生产规模1711Mt/a 。

开采煤层为3#
煤和9#煤。

3#煤层平均厚度约6104m ,9#煤层平均厚
约115m 。

煤的硬度为中硬,密度1145t/m 3。

煤质为优质无烟煤,主要用于化工。

由于块煤产品用于化工合成氨造气优于焦碳,故市场竞争力很强,经济效益显著。

多年来,企业一直把提高产品块率列为生产中的关键技术进行攻关,其中研究设计高效高块率采煤机是提高煤炭块率的源头和关键。

为此,集团机修总厂不断地进行采煤机螺旋滚筒的技术改造。

首先,开发研制了AM500、MX A600采煤机的高效高块率螺旋滚筒,在古书院矿3#煤层13309工作面下分层开采中,块率增加约4%。

在此基础上对第二代滚筒结构参数又进行了优化改进,改进后装载率高于95%,块率提高到5%。

并开发研制了用于9#煤生产的直径114m 滚筒,井下使用过程中,性
能优于原厂家制造的AM500(薄)采煤机滚筒。

把高效高块率滚筒设计的参数应用到MG 250/6002AW D 采煤机滚筒上,并在凤凰山矿井使用,性能
优于原厂家制造的采煤机滚筒。

实践证明,高效高块率采煤机滚筒的改造技术上可行,经济效益明显。

1　采煤机螺旋滚筒截齿技术改造111　截齿截入深度
结合晋城3#煤硬度为中硬的特点,本厂研制的采煤机螺旋滚筒选用镐形截齿。

镐形截齿刀尖呈
圆锥形,刀头材料为硬质合金,没有切削刃,利用点击和尖劈作用来截煤和破煤。

采煤机截煤时截齿受力简图如图1所示。

截齿的截割阻力与截齿截入深度成正比。

图1　镐形截齿截煤受力简图
即Z =Ah (N )
式中,Z 为截割阻力(N );A 为截割阻力系数(N/cm );h 为截齿截入深度(cm )。

A 值反映被截割煤的机械性能。

推进阻力Y 是在截齿向煤层推进时产生的,主要与截齿的类型、磨钝程度、截槽形状和煤的机械性能有关。

根据煤层的地质条件和要截割煤的机械性能,为了达到良好的出煤块度,必须合理确定截齿的截入深度。

截齿的截入深度是和滚筒的转速、采煤机的牵引速度相关的。

如图2、图3所示。

为了达到滚筒高效高块率截煤的效果,还必须加大单齿截深和切削面积。

随着截齿截入煤体深度的加大,使被截割煤体中包容大量的裂缝,截煤时煤从裂缝中破碎,相对减少了截齿的单位能耗,摩擦力在总截割阻力中所占的比重也相应减少。

俄罗斯柯琴斯基矿业研究院的研究结论表明,单齿的截割深度达50～80mm 时,其能耗最低,其单齿切割
5
7
面积可达到15～50cm 2。

在煤质许可的条件下,要
达到高效高块率的截割目的,单齿截割深度及切削面积应最接近或达到其上限的规定。

根据上述分析,本厂在改造AM500采煤机滚筒时,研制了TG 118/6130滚筒,选用伸出长度较大的镐形截齿J G T35/100。

在古书院矿3#煤层13309工作面下分层开采中,经过现场多次试验,表明采煤机滚筒转速为31r/min ,推进速度为6m/min ,截齿的截入深度最大可达到80mm ,单齿切割面积可达到36～40cm 2,其截面形状接近于长方形,此时滚筒具有较好的截割性能和较高的块率。

图2　
截齿截入深度与滚筒转速的关系
图3　截齿截入深度与推进速度的关系
112　截齿的排列
滚筒上截齿的数量和排列方式直接影响截割时的能量消耗、落煤的块度和煤尘量的大小。

一般采煤机截煤时的截割状态可以分为4类,即自由截割、半自由截割、半封闭截割、封闭截割。

滚筒断盘上最里面截齿的截割状态是半封闭状态,所形成的截槽是半封闭式截槽,截齿的侧向力较大。

故端盘截齿的排列必须考虑减少截割阻力和截齿的磨损,保证截齿的截割强度,降低截割时的能量消耗。

可见,对端盘截齿的数量及倾角进行优选排列,对提高滚筒的截割能力有积极的效果。

本厂在制造TG 118/6130滚筒时,参考了美国凯南麦特公司滚筒的截齿排列,太矿制造的MG 375/8302W D 采煤机滚筒的截齿排列。

凯南麦特
公司滚筒的截齿排列是<118m 的滚筒布置了33个截齿,端盘均匀布置18个截齿,倾角5～35°,其中35°倾角截齿6个,3条螺旋叶片,每个叶片分布5个齿,一条截线1个齿。

太矿MG 375/8302W D 采煤机滚筒的截齿排列布置了40个,端盘均匀布置21个截齿,倾角-2～45°,其中45°倾角截齿6个,3条螺旋叶片分布截齿分别为7个、6个、6个,也是一条截线1个齿。

本厂研制的TG 118/6130滚筒在此基础上,结合本地区开采煤层的特点和以往的使用情况,把截齿减少到30个。

截齿排列方式是端盘均匀布置17个截齿,其中45°倾角截齿6个;25°,35°倾角截齿各3个;-5°,-10°,0°,10°,15°倾角截齿各1个。

采用3条螺旋叶片,分布截齿分别为8个、8个、5个,1条截线1个截齿的布置形式。

按以上技术改造后,研制的TG 118/6130滚筒和AM500采煤机配套使用在古书院矿3#煤层13309工作面下分层回采工作面中试采,现场使用
反映良好,滚筒具有较好的截割状态和较高的块率,与改造前的螺旋滚筒相比,工作面块率提高了4%左右。

2　采煤机螺旋滚筒结构技术改造211　螺旋滚筒直径(D w )
滚筒直径也是影响出煤块度的因素之一。

选择
直径大一些滚筒,有利于降低临界转速,提高装煤效果,但直径过大时,会增加能耗,减小煤的块
度。

当滚筒直径减小时,装煤效率会降低。

一般采
煤机螺旋滚筒直径是根据开采煤层高度确定的,为了增加出煤块度,德国艾柯夫公司研究认为滚筒直径要满足D w ≥S /118536(式中,D w 为滚筒直径,m ;S 为采高,m )。

3#煤层厚度约610m 左右,回采工艺既有分层开采也有综采放顶煤开采,工作面采高都在310m 左右,煤质硬度为中硬。

结合以往使用情况,采用直径118m 的滚筒较为合理。

212　筒体直径(D y )
筒体直径大小决定于叶片高度,筒体直径越大,叶片高度就越小,叶片间的煤流有效空间就越小,容易出现煤流的饱和发生堵塞现象。

因此,从提高滚筒装煤能力着想,在保证叶片与筒体的焊接强度,满足摇臂头传动装置的安装空间的前提下,滚筒的筒体直径应取小一些。

晋煤集团公司过去常用的AM500,MX A600采煤机,MG 375/8302W D 电牵引采煤机118m 滚筒的筒体直径为980mm ,现在使用的MG 250/6002W D 电牵引采煤机118m 滚筒的
6
7
筒体,直径为780mm ,相对叶片高度增加100mm ,
极大地提高了装煤效率。

装煤效率的提高也相应减少了煤体之间的碰撞,间接地提高了块率。

213　螺旋叶片的头数
螺旋叶片的头数决定了螺旋叶片的导程L ,L =S ×m (式中,S 为螺距;m 为叶片头数),而导程应不小于叶片宽度B y ,即L >B y 。

因此,头数必须满足S ×m >B y ,即m >B y /S 。

通常叶片的头数m =2～4,如果头数过多,叶片的间距S 减小,煤流空间狭窄,将增加阻力和能耗,理论上推荐S =250～400mm 。

故本厂在制造<118m G 18/6130滚筒时,确定螺旋叶片头数m =3。

214　叶片的螺旋角
叶片的螺旋角通常指叶片外径处的螺旋角,螺旋角是影响滚筒装煤的决定性因素。

一般来说,螺旋角越大,排煤的能力也越大,但螺旋角过大时,容易引起煤尘飞扬。

螺旋角过小,叶片的排煤能力小,煤在螺旋叶片内循环,造成煤的重复破碎,使能量消耗增大。

经验表明,螺旋角在10～24°范围内,装煤效果较好。

凯南麦特公司的滚筒叶片的螺旋角为17°。

本厂制造的<118m TG 18/6130滚筒叶片的螺旋角为16°。

215　叶片的安装倾角
叶片的安装倾角影响叶片的装煤性能。

一般滚筒叶片沿轴向截断面与其轴线垂直安装。

根据英国纽卡斯特尔大学的试验结果,如果该截断面向装载侧倾斜β=7～10°,则可使叶片的装煤效果提高10%左右。

本厂研制的螺旋滚筒,镐型截齿伸出长度大,并且齿座结构特殊,使主叶片的装载能力受到很大影响。

所以,产品在设计时,对主叶片只考虑到其截割性能,另设厚度16m m 的装载副叶片,装载副叶片不仅具有完整光滑的装载表面,并且在轴线上向装载侧倾斜8°,如图4所示。

副叶片与主叶片加焊封板,形成楔形结构,
减小了径向截煤和排煤阻力。

图4　叶片安装
1—主叶片;2—副叶片;3—封板
根据上述理论对TG 18/6130滚筒的结构参数进行的优化改进,使第二代滚筒在3#煤层工作面回采过程中取得了良好的装载效果,TG 18/6130滚筒的装载效率高达95%,同时也避免了落煤在滚筒叶片间产生第二次破碎,块率提高到了5%左右。

3　制造采煤机螺旋滚筒的主要工艺措施
为了保证产品质量,符合设计要求,达到部颁标准,制造时必须有完善的工艺措施,工艺装备和工艺手段。

采取的主要工艺措施有以下几点:
(1)其具有焊弧热量集中,熔池深,焊缝强度高的特点。

(2)螺旋叶片、滚筒端盘要采用专用模具压制。

(3)对截齿、齿座、齿靴等外购件在使用前必须严格检测。

(4)齿座组焊要在专用胎具上施焊,并及时利用样板截齿检测齿座的焊接位置。

齿座焊接时必须对齿座焊缝周围的母体进行预热,预热温度为200℃,以减少焊接应力。

(5)装载叶片的出口端要堆焊90#高铬铸铁焊条,要求硬度达到HRC50左右,增加耐磨性能。

(6)滚筒各件焊接后要及时利用TZ 221型震动时效装置进行时效处理,以消除或减少焊接应力。

4　结论
通过对采煤机螺旋滚筒的技术改造和制造工艺质量保证措施,近5年来,本厂研制的<118m ,<114m 的螺旋滚筒已生产了24个,和A M500,MX A600,MG 375/8302W D ,MG 250/6002W D ,MG 250/6002A W D 等型号的采煤机配套使用,在集团公司的4个生产矿井现场运行效果良好,工作面生产效率
和出煤块率较改造前都有提高,达到了技术改造的目的。

实践证明,高效高块率采煤机螺旋滚筒的改造技术上可行,经济效益明显。

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[责任编辑:邹正立]
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煤　矿　开　采ENG L ISH　ABSTRACTS
A trial study on longw all top-coal caving mining u nder s and-prevention and caving-prevention pillars near strata outcrop zone—In X ingtai coal m ine,according to the principle of probing in advance and m ining later,near the outcrop z one of extra-thick loose water-bearing strata,long wall top-coal caving m ining is achieved in 6.4m thick coal seam under the condition of retaining12-51m sand -prevention and caving-prevention pillars.
T he type determination o f pow ered supports and its autom atic control for thin-seam mining—T his paper presents the principle to determ ine the ty pe of powered support for thin coal seam m ining,and points out the characters of main technical parameters of ZY6400/09/20 powered support.M oreover,the function of automatic control system of this powered support is brie fly introduced.
The layout ch aracters and the present problems of mining road2 w ays and its developing trends in Xinglongzhu ang coal mine—This paper summarizes the characters of mining roadway lay out adopted in thick coal-seam mining in X inglongzhuang coal mine. T o meet the requirement of mining technology innovation,as a de2 veloping trend,mining roadways in thick coal seams of X ing2 longzhuang coal mine should be totally located in coal seam.
The design method of dynamic bolting inform ation and its ap2 plication in Ch angcun coal mine—As an extensively acknowl2 edged bolting design method for coal roadway support,the dynamic in formation design has tw o obvious characters,that is,it is a dy2 namic process,in which all kinds of in formation are fully utilized. The application of dynamic in formation design method in the large-section roadway which is difficult to support and in fluenced by geo2 logical structures is illustrated in the S3total air-return roadway in Changcun coal mine of Lu’an C oal G roup.According to the analy2 sis of ground behavior m onitoring data,the validity of roadway sup2 porting is evaluated.
To reinforce the large-sp an and sm all-coal-pillar roadw ay by prestressed injection and cable anchors—This paper presents the application of dynamic stress in formation design method in the supporting design of s520transportation roadway with small pillars and large span,which is simultaneously in fluenced by geological structures and mining rge m odels are established to stimulate the different rein forcement plans and supporting parame2 ters,s o the best rein forcement plan is determined,that is,we should adopt the new technology of united support with small-di2 ameter resin injection and prestressed bolting shetcrete.Meanwhile, the support mechanism and results of ground behavior m onitoring is analyzed.The study shows that the rein forced plan is fairly rational and reliable.
Study on the deform ation mech anism of soft-rock roadw ay and its m ain countermeasures—According to the analysis of de2 formation mechanism of s oft-rock roadway,this paper presents s ome effective measures to control s oft rock deformation.
The simulation on the la w s of top-coal and roof movement in suspensive-advancing support caving mining in flat-dipping thick seam—Using the methods of equivalent material m odel test, this paper studies the laws of roof m ovement in suspensive-advanc2 ing support caving mining in the thick coal seam with gentle dip an2 gle in Daanshan coal mine of Beijing coal mining Administration, preliminarily summarizes the laws of roof m ovement and ground be2 haviors The studies provide an important basis and direction role for determination of the rational plan and safety technical measures in caving mining.
The la w s of roof movement in longw all top-coal coving face with light hydraulic support in thinner thickness and greeter angle seam—Aimed at the current situation of long wall top-coal caving mining with light hydraulic support in thinner thick-seam with great dip angle in D onghuansuo Mine of K ailuan G roup,adopt2 ed the method of deep basepiont observation,the laws of deforma2 tion,m ovement,fracturing and caving of top-coal and roof are an2 alyzed in this paper.The study provides s ome theoretical basis for determination of important technical parameters such as drawing height and drawing interval.
F ast lagrangian large-deform ation analysis for the second miningg of botlom coal—Adopting F LAC3D,the effect of top-coal thickness in second miming on the parameters such as roof-floor displacements,maximum and minimum principle stresses and their ev olution laws are studied in this paper The simulation results provide the theoretical basis for the determination of top-coal thick2 ness and the success mining.
Study on the instability m ech anism o f light-caving support in greater dip angle seam—T his paper extensively analy zes the mecha2 nism of support instability in long wall top--coal caving m ining w ith light hydraulic support mgreat andle seam C entered on the arrangement and management of the process,s ome technical measures to im prove support stability are presented.
Evalu ation and control of the mining d am age under highw ay—This paper discusses the evaluation and control ways for mining damage in rein forced-concrete highway in detail,and presents a practical formula for calculation of the crevice width between tw o plates in road surface.The studies provide a scientific basis for the design and maintenance of highways in coal mining district.These are very important in coordinating the relations between the mine and the highway administration to realize the protective mining. Analysis of CO poisoning accident caused by mine fire with ac2 cident-tree method—The idea and method of accident tree are presented and used to analyze a C O pois oning accident caused by mine fire.An example is provided to dem onstrate the feasibility and actuality of the method.The way to prevent mine fire is discussed. T echnical innovation of screw drum for the shearer with high efficiency and high lump rate—Based on the mining characters of coal seam in Jincheng mining district,proceeding from the purpose to increase the coal lump rate and loading efficiency,this paper an2 alyzes s ome key problems of technical innovation on the cutter bit, the structure of the spiral drum and technological measures.
(王明立,胡炳南　译　富　强　校)。