鶴壁六礦150萬噸新井設(shè)計【含CAD圖紙+文檔】
鶴壁六礦150萬噸新井設(shè)計【含CAD圖紙+文檔】,含CAD圖紙+文檔,鶴壁,萬噸新井,設(shè)計,cad,圖紙,文檔
附錄A（原文）
中厚煤層懸移支架放頂煤技術(shù)
【摘要】中厚煤層在我國部分礦區(qū)賦存廣泛,文中介紹了中厚煤層懸移邁步支架放頂煤技術(shù),通過實踐與研究,得出了一些體會和認識,為類似條件煤層的開采提供了借鑒經(jīng)驗。
1 引言
煤厚在3.5～5ｍ的中厚煤層在我國邯鄲、峰峰、平頂山、淮南、徐州、大屯、西山等礦務(wù)局及一些地方礦廣泛賦存,隨著放頂煤工藝的迅速發(fā)展,中厚煤層開采方法也發(fā)生深刻的變革,由原分層開采逐漸轉(zhuǎn)向大采高整層開采和放頂煤開采;與分層開采相比,大采高和放頂煤開采不僅大幅度提高工作面的產(chǎn)量、效率,減少掘進率和維修費用,降低成本,而且簡化了生產(chǎn)系統(tǒng),實現(xiàn)了集中生產(chǎn)。由于大采高存在設(shè)備笨重 ,初期投資大,松軟煤層的防片幫難以解決和破碎頂板難以控制等問題,部分局礦試驗采用放頂煤開采,但中厚煤層放頂煤開采存在以下兩個主要問題:①煤厚較小,在采煤機割煤后頂煤厚度一般小于3ｍ,通過大量現(xiàn)場實測和實驗室模擬試驗表明,當頂煤厚度小于2.5～3ｍ時,在頂煤放落過程中呈類似偽頂無規(guī)則冒落狀態(tài),造成煤矸混合,使采出率降低。②頂煤厚度較小,易產(chǎn)生離層、斷裂,造成支架控制頂板困難,特別是端面無支護空間的頂煤,隨時可能發(fā)生冒落,從而引起直接頂冒頂,控制端面頂煤是中厚煤層放頂煤開采取得成功的關(guān)鍵技術(shù)之一。
如何根據(jù)礦井的具體條件,選擇合適的架型和適當?shù)墓に囀侵泻衩簩幽芊袢〉贸晒Φ年P(guān)鍵,孔莊礦在7177工作面采用了ＺＷＭ網(wǎng)格式懸移支架放頂煤技術(shù)。
2 工作面基本概況
孔莊礦7177工作面走向長350ｍ,傾斜長平均100ｍ,工作面上部境界為Ｆ6-6斷層,落差152ｍ;下部境界Ｆ8斷層,落差21ｍ。所采煤層為7#煤,賦存穩(wěn)定,煤層中硬,煤厚4～5.36ｍ,平均5.0ｍ,煤層傾角平均24°。煤層直接頂為灰黑色砂巖與灰白色細砂巖互層,厚5.6ｍ,易冒落;老頂為頁巖,厚8.5ｍ,節(jié)理發(fā)育,易冒落;煤層直接底為泥巖,厚1.4ｍ。工作面內(nèi)受Ｆ6-6和Ｆ8斷層的影響,伴生的小斷層比較發(fā)育。礦井瓦斯等級為低瓦斯礦井,煤層自然發(fā)火期為6～12個月。
3?。冢祝途W(wǎng)格式懸移邁步放頂煤支架概況
ＺＷＭ網(wǎng)格式懸移邁步支架,是介于綜采放頂煤支架和滑移頂梁之間的一種過渡式支架,它由主、副架組成,主、副架均由頂梁和三根液壓支柱組成,主、副梁通過一對降架滑塊作為降架機構(gòu),其架與架之間用一對可伸縮的聯(lián)接臂相連,使全工作面所有在用支架全都聯(lián)成一個整體,整個工作面支架梁體形成網(wǎng)絡(luò)狀,主梁前端裝有翻板式前探梁,主副梁的后端都裝有箱體式“弓”形尾梁,上下行人以及放煤作業(yè)等都在后尾梁的掩護之下,大大增強了穩(wěn)定性、安全性,而且有一個比較舒適寬敞的作業(yè)環(huán)境,支架支撐高度為1.8～2.4ｍ,設(shè)計初撐力為900ｋＮ,額定工作阻力為1800ｋＮ,最大控頂距為3.65ｍ,最小控頂距為3.05ｍ。架間中心距1.1ｍ,支架體積小、重量輕,支架的運輸、安裝、拆卸、更換、調(diào)架、操作比較方便靈活。
4 采放工藝
(1)割煤、運煤。工作面使用國產(chǎn)ＭＧ-150ＡＷ型雙滾筒采煤機落煤,采煤機截深為0.6ｍ,進刀方式為端頭斜切進刀,采煤高度為2.1ｍ,放頂煤厚1.9～3.26ｍ,割煤采用ＳＧＤ-220型刮板運輸機運輸,放頂煤采用ＳＧＷ-40刮板運輸機運輸。
(2)鋪網(wǎng)、聯(lián)網(wǎng)。頂鋪金屬菱形網(wǎng),網(wǎng)寬0.7ｍ,長5.6ｍ,材料為10#鍍鋅鐵絲,網(wǎng)孔為60×60ｍｍ,聯(lián)網(wǎng)采用14#鍍鋅鐵絲,隔孔雙股勾擰3圈,人工鋪聯(lián)網(wǎng),鋪網(wǎng)滯后采煤機5～10ｍ,通過升起支架前探梁壓緊鋪好的金屬網(wǎng)進行臨時支護,同時在煤壁每4～5ｍ采用ＤＺ-2500型單體支柱打帶帽點柱作為煤壁空頂區(qū)的臨時支護。
(3)移架。要注意及時支護,采煤機割煤后要及時移架,追機移架距離不大于2架,移架速度慢時應(yīng)降低割煤速度。移架時先收回副架前探梁,升起副架三根支柱,前移副架0.6ｍ,注液升柱,類似副架操作,前移主架0.6ｍ,移完整架后再移相鄰一架。
(4)放頂煤。經(jīng)試驗確定工作面放煤工藝為兩采一放,放煤步距為1.2ｍ,采用自下而上單輪間隔放煤方式。采用低位放煤,放煤口剪成“Ⅰ”型,長0.4ｍ,下口距溜子上沿100ｍｍ,放煤口間距1.1ｍ,同時開啟的放煤口不超過3個,放煤見矸后立即封網(wǎng),網(wǎng)口采用“#”型封口。
(5)循環(huán)作業(yè)方式。循環(huán)作業(yè)方式采用三八制,兩班生產(chǎn)一班檢修。
5 工作面礦壓顯現(xiàn)規(guī)律
通過對7177工作面支架工作阻力等參數(shù)測試表明,頂板初次來壓步距為19～29ｍ,工作面上、中部初次來壓步距基本相近,工作面下部初次來壓步距大于該面中上部。周期來壓步距平均為9.6ｍ。工作面動載系數(shù)平均為1.25,最大1.43。支架工作阻力服從正態(tài)分布,但分布中值極不合理,工作阻力利用率低,不足工作阻力1/3的支架占全工作面的84%。
7177工作面來壓期間礦壓顯現(xiàn)劇烈,顯現(xiàn)特征除支架載荷增大外,明顯表現(xiàn)出工作面頂煤被壓碎、煤壁片幫(片幫深度10～100ｃｍ不等 )、架前冒頂(冒頂高度最大達3ｍ左右)、臺階下沉和支柱插底等現(xiàn)象, 7177工作面初次來壓時,沿煤壁切頂線長達30ｍ左右,支柱鉆底量大,特別是后柱,最大達80～100ｃｍ,致使工作面支架呈“高射炮”狀,在來壓期間還出現(xiàn)支架咬架、支柱脫窩、頂梁翻轉(zhuǎn)等現(xiàn)象,支架部件損壞嚴重。
7177工作面割完第一刀煤后,中班在移架過程中發(fā)生了推跨性冒頂事故,支架從20～43#倒架24架;工作面推進到66ｍ時, 21～24#支架推向煤幫,影響了工作的正常生產(chǎn)。
6 煤塵、自然發(fā)火防治
(1)煤塵的防治:對煤層超前打眼注水,注水后煤體的含水率由2%提高到3.5%,另沿工作面老塘側(cè)專設(shè)了一條防塵管路,用于放煤時防塵。
(2)煤層自然發(fā)火防治:主要采取向采空區(qū)注黃泥漿、提高采出率及減少采空區(qū)漏風等措施,回采期間未出現(xiàn)煤層自然發(fā)火現(xiàn)象。
7 經(jīng)濟效益分析
據(jù)統(tǒng)計7177工作面的采出率為87.7%,與類似條件7#煤分層開采相比提高了9個百分點。
根據(jù)對孔莊礦7#煤放頂煤開采與分層開采經(jīng)濟比較,結(jié)果表明,放頂煤開采由于直接工效提高,成本降低2.93元/ｔ,巷道掘進費用低5.44元/ｔ,維護費用低0.57元/ｔ,設(shè)備租賃費用低0.81元/ｔ,材料消耗低5.85元/ｔ,放頂煤開采比分層開采總成本降低15.60元/ｔ。
8 主要體會和認識
(1)ＺＷＭ網(wǎng)格懸移支架經(jīng)受了7177工作面初次來壓、周期來壓、過斷層、過老峒、過破碎帶等條件的考驗,證明支架設(shè)計基本合理,但架子部分焊接件焊接質(zhì)量差,特別是降架滑塊的滑盤、聯(lián)接臂的加長臂,普遍焊接不好;
(2)支架的結(jié)構(gòu)要與頂板和煤層條件相適應(yīng),且要保證支架工作的穩(wěn)定性。從有利于頂板管理和放煤效果考慮,頂煤較硬的宜選用頂梁較長的架型,頂煤較軟易片幫抽頂?shù)囊诉x用頂梁短的架型。實踐表明類似7177工作面條件,宜選用較短梁的懸移支架為宜,且要進一步提高ＺＷＭ網(wǎng)格支架穩(wěn)定性,防止支架倒架、擠架事故的發(fā)生;
(3)工作面采高必須嚴格控制 ,超高后架子不穩(wěn),同時會造成頂煤過薄,使放煤時含矸率上升,采高過低會造成尾梁與梁體形成馬鞍形,移架困難,影響安全與生產(chǎn);
(4)針對7177工作面管理的特點,在支護上應(yīng)采用“支、護、控、穩(wěn)”兼顧,以“護、控”為主的原則。 7177工作面支架載荷并不大,支架有足夠的設(shè)計初撐力和工作阻力,為了控制頂煤的穩(wěn)定性,保持一定的初撐力和合理的工作阻力是必要的,也即“支”?！白o”的主要目的的是最大限度的控制頂煤冒漏、煤壁片幫等事故發(fā)生,同時為“支”創(chuàng)造良好條件,因此“護”是“支”的前提,護不好頂就支不上勁,一方面應(yīng)盡可能減少端面控頂距,加強工作面支架端面支護能力,控制工作面機道上方頂煤不冒落;另一方面需及時支護,實施擦頂移架,加強護頂?！翱亍奔纯刂浦е@底,提高支護系統(tǒng)剛度,采取的方案應(yīng)是將底板浮煤清理干凈,或按照底板抗壓入強度,給支柱穿鞋,必要時可采用底梁等措施。“穩(wěn)”即保證支架的穩(wěn)定性,防止歪架、倒架,杜絕事故的發(fā)生。由于ＺＷＭ網(wǎng)格支架自身上重下輕,屬不穩(wěn)定結(jié)構(gòu),支架梁柱位置及整架的狀態(tài),均比綜放支架靈活,所以一旦操作不慎,梁柱位置不合理,輕則支護阻力不夠,重則損壞支架甚至出現(xiàn)倒架事故,故工人技術(shù)及管理水平在支架使用中起到很大作用,應(yīng)加強工作面生產(chǎn)管理,要控制好支柱頂梁位置、相對關(guān)系和位態(tài),防止支柱迎山不夠、支架歪斜、頂梁竄位等;
(5)該網(wǎng)格支架既可與機采配合又可與炮采配合,其初期投資僅相當于綜放支架總投資的五分之一至八分之一左右,它具有體積小、重量輕、結(jié)構(gòu)簡單、安裝和運輸方便、操作容易等優(yōu)點,對回采地質(zhì)條件復(fù)雜和邊角塊段煤層具有較好的靈活適應(yīng)性,因此在目前煤礦經(jīng)濟普遍困難的情況下,其適合于中小煤礦。正確使用ＺＷＭ支架放頂煤和采取得力的措施,可以充分發(fā)揮其靈活、適應(yīng)性強、成本低、半自動化、安全和高產(chǎn)高效的優(yōu)點。
附錄B（英文翻譯）
The thick seam hangs moves
the support to put goes against the coal technology
[Abstract]The thick seam saves widely in our country partial mining area tax, in the article introduced the thick seam hangs moves takes a step the support to put goes against the coal technology, through the practice and the research, has obtained some experiences and the understanding, has provided the model experience for similar condition coal bed mining.
1 Introduction
Coal thick in the 3.5~5m thick seam in mining bureaus and some place ore widespread tax and so on our country Handan, Feng Feng, Pingdingshan, Huai Nan, Hsuchou, Tatun, Xishan saves, along with puts goes against the coal craft the rapid development, the thick seam method of exploitation also has the profound transformation, changes gradually by original lamination mining picks Gao Zhengceng to mine and to put greatly goes against coal mining; Compares with lamination mining, not only picks Gao He to put greatly goes against coal mining to enhance the working surface large scale the output, the efficiency, reduces the drivage ratio and the maintenance cost, reduces the cost, moreover simplified the production system, has realized the centralism production.Because picks greatly has the equipment to be unwieldy high, the initial investment is big, the soft coal bed guards against the cave-in of sides of a mine tunnel to solve and the stave roof with difficulty controls and so on the questions with difficulty, the sub-bureau ore experiment uses puts goes against coal mining, but the thick seam puts goes against coal mining to have following two main problems:①Coal thick small, goes against the coal thickness after the coal mining machine coal cutting to be smaller than generally 3m, actual and the laboratory simulation experiment indicated through the massive scenes, is at the highest point when coal thickness is smaller than 2.5~3m, in goes against the coal to put falls in the process to assume the similar false roof without the rule to brave to fall the condition, creates the coal gangue mix, causes to pick rate reduces.②Goes against the coal thickness to be small, easy to produce the abscission layer, the break, creates the support control roof to be difficult, specially the end surface non-supports and protections space goes against the coal, possibly occurs as necessary braves to fall, thus causes goes against braves to go against, controls the end surface to go against the coal is directly the thick seam puts goes against coal mining to obtain one of success key technologies. How acts according to the mine pit the concrete term, whether chose the appropriate frame and the suitable craft is the thick seam obtains the success the key, Kong Zhuangkuang uses the ZWM grid type in 7177 working surfaces to hang moves the support to put goes against the coal technology.
2 Working surface basic survey
Kong Zhuangkuang7177 working surfaces move towards long 350m, inclines long average 100m, on the working surface the boundary is the F6-6 fault, dropping variance 152m; Lower part boundary F8 fault, dropping variance 21m.Mines coal the level is the 7# coal, the tax saves stably, in coal bed hard, coal thick 4~5.36m, average 5.0m, coal bed inclination angle average 24°.The coal bed goes against directly for the cinereus sandstone and the iron grey novaculite interbed, thick 5.6m, Yi Maoluo; Always goes against for the shale, thick 8.5m, jointing growth, Yi Maoluo; The coal bed direct bottom is the mudstone, thick 1.4m.In working surface F6-6 and F8 fault influence, associated minor fault comparison growth.The damp rank is the low gas mine pit, the coal bed spontaneous combustion time is 6~12 months.
3 ZWM grid type hangs moves takes a step to put goes against the coal support survey
ZWM grid type to hang moves takes a step the support, is situated between the synthesis to pick puts goes against between the coal support and the slipping top-beam one kind of transition type support, it by the host, the sub-frame is composed, the host, the sub-frame are composed by the top-beam and three hydraulic pressure props, the host, the subsidiary spar fall the slide achievement through one pair to fall an organization, between its and is connected with a pair of expandable joint arm, causes the entire working surface to possess in uses the support all to connect a whole, the entire working surface supporting beam build becomes the network shape, front end the king post is loaded with vane type throat Liang, main subsidiary spar rear endAll is loaded with the box writing style “the bow” the shape stabilizing bar, about the pedestrian as well as puts the coal work and so on all on under after stabilizing bar shield, strengthened the stability, the security greatly, moreover has a quite comfortable spacious work environment, the support support is highly 1.8~2.4m, at the beginning of the design supports the strength is 900kN, the fixed working resistance is 1800kN, controls the zenith distance is most greatly 3.65m, slightly controls the zenith distance is 3.05m.Bay center distance 1.1m, the support volume small, the weight is light, the support transportation, the installment, the disassemblage, the replacement, the accent frame, the operation quite are convenient nimbly.
4 Picks puts the craft
(1) Coal cutting, transports the coal.The working surface use domestic product MG-150AW double roll coal mining machine falls the coal, the coal mining machine truncation depth is 0.6m, the feed way for the reason bevelling feed, mining coal is highly 2.1m, puts goes against coal thick 1.9~3.26m, the coal cutting uses the SGD-220 scraper chain conveyor transportation, puts goes against the coal to use the SGW-40 scraper chain conveyor transportation.
(2) Shop net, networking.Goes against the shop metal diamond network, the net extends 0.7m, long 5.6m, the material is the 10# galvanized wire, mesh for 60×60mm, the networking uses the 14# galvanized wire, separates the hole double strand to cancel twists 3, the artificial shop networking, spreads net lag coal mining machine 5~10m, through raises support throat Liang to contract the shop good wire netting to carry on the temporary supports and protections, simultaneously uses the DZ-2500 monomer prop in coal wall each 4~5m to hit a belt hat column to go against the area spatially as the coal wall the temporary supports and protections.
(3) Moves the frame.Must pay attention to the prompt supports and protections, after the coal mining machine coal cutting must move promptly the frame, pursues machine moves a distance not to be bigger than 2, moves a speed slowly when should reduce the coal cutting speed.Moves when takes back sub-frame throat Liang first, raises the sub-frame three props, first moves sub-frame 0.6m, the fluid injection rises the column, the similar sub-frame operation, first moves main frame 0.6m, after moves integrity to move again neighboring.
(4) Puts goes against the coal.After the experiment determined as soon as the working surface puts the coal craft is two picks puts, puts a coal step distance is 1.2m, uses the monowheel gap to put the coal way from bottom to top.Uses the low position to put the coal, puts the coal mouth to cut “Ⅰ” Long 0.4m, the end opening is apart from on the chute along 100mm, puts coal mouth spacing 1.1m, simultaneously opens puts the coal mouth not to surpass 3, after puts the coal to see the gangue to block immediately, net mouth use “#” seal.
(5) Cycle operation way.The cycle operation way uses 38 systems, two classes produce one class to overhaul.
5 Working surface ores
Press the appearance rule through to parameter tests and so on 7177 working surface support working resistance to indicate that, the roof first presses a step distance is 19~29m, in the working surface, middle first presses a step distance basically close, lower part the working surface first presses a step distance to be bigger than in this upside.The cycle presses a step distance is equally 9.6m.The working surface moving load coefficient is equally 1.25, biggest 1.43.Support working resistance obedience normal distribution, but distributes the value not to be extremely unreasonable, the working resistance use factor is low, the insufficient working resistance 1/3 support occupies the entire working surface 84%.
7177 working surfaces press the period ore to press the appearance to be fierce, the appearance characteristic increases besides the support load, displays the working surface to go against the coal obviously to crush, the coal wall cave-in of sides of a mine tunnel (cave-in of sides of a mine tunnel depth 10~100cm does not wait), in front of to brave to go against (braves to go against highly reaches most greatly about 3m), the stair submersion and the prop inserts phenomena and so on bottom, when 7177 working surfaces first press, cuts the crest line along the coal wall long to reach about 30m, the prop drills the bottom quantity to be big, after specially the column, most greatly reaches 80~100cm, causes the working surface support to assume “the anti-aircraft gun” the shape, in presses the period also appears the support to fight, the prop escapes the nest, the top-beam turn over and so onThe phenomenon, the support part damage is serious.
After 7177 working surfaces shear the first knife coal, the middle shift in moved in a process to occur has pushed cross to brave to go against the accident, the support lost face 24 from 20~43#; When the working surface advances to 66m, the 21~24# support pushes to the coal gang, has affected the work regular production.
6 Coal dust, the spontaneous combustion prevent and control
(1) Coal dust preventing and controlling: Drills the irrigation in advance to the coal bed, after the irrigation the coal body moisture content from 2% enhances to 3.5%, specially has in addition supposed a dustproof pipeline along the working surface old pond side, uses in putting time the coal dustproof.
(2) coal bed spontaneous combustion preventing and controlling: Mainly adopts to picks the depletion region note yellow mud, the enhancement picks rate and the reduction picks the depletion region to leak out and so on the measures, returns picks the period has not appeared the coal bed spontaneous combustion phenomenon.
7 Economic efficiency analyses
Picks according to the statistical 7177 working surfaces rate is 87.7%, compared with similar condition 7# coal lamination mining enhanced 9 percentage points. According to coal puts to Kong Zhuangkuang the 7# goes against coal mining and the lamination mining economy compares, finally indicated, puts goes against coal mining because the direct work efficiency enhances, cost reduction 2.93 Yuan /t, tunnel tunneling expense low 5.44 Yuan /t, maintenance cost low 0.57 Yuan /t, the equipment rents expense low 0.81 Yuan /t, the material consumes low 5.85 Yuan /t, puts goes against coal mining to reduce 15.60 Yuan /t compared to the lamination mining total cost.
8 Mainly realized and knew
(1)ZWM grid hung moves the support to undergo 7177 working surfaces first to press, the cycle presses, the fault, the old cave, condition and so on crushed zone tests, proved the support design basically reasonable, but the rack partial weldment welding quality was bad, specially fell a slide the slippery plate, joins the arm the extension arm, the universal welding was not good.
(2) Support structure must adapts with the roof and the coal bed condition, also must guarantee the support work the stability.From is advantageous and puts the coal effect in the roof management to consider that, goes against the coal hardly to select the top-beam long frame suitably, goes against the coal to be soft the easy cave-in of sides of a mine tunnel to pull out goes against selects the top-beam short frame suitably.The practice indicated the similar 7177 working surface condition, selects short Liang to hang suitably moves the support for suitably, also must further enhance the ZWM grid support stability, prevented the support loses face, pushes the accident occurrence.
(3) Working surface picks high must control strictly, after the superelevation the rack is not steady, simultaneously can create goes against the coal excessively to be thin, causes puts when the coal the percentage of refuse content rise, picks Gao Guodi to be able to create the stabilizing bar and the Liang build becomes saddle-shaped, moves a difficulty, affects the security and the production.
(4) Aims at 7177 working surface management the characteristic, should use “in the supports and protections, protect, controls, the proper attention to both steadily”, by “protects, controls” the primarily principle. 7177 working surface support load is not big, the support has the enough at the beginning of design to support the strength and the working resistance, in order to control goes against the coal the stability, maintains certain initially supports the strength and the reasonable working resistance is necessary, also namely “”.“Protects” the main purpose is the maximum limit control goes against the coal to brave to leak, accidents and so on coal wall cave-in of sides of a mine tunnel occurs, simultaneously is “” the creation good condition, therefore “protects” is “” the premise, protects goes against not well on a not zeal, on the one hand should reduce the end surface to control the zenith distance as far as possible, strengthens the working surface support end surface supports and protections ability, controls above working surface machine to go against the coal not to brave to fall; On the other hand needs the prompt supports and protections, the implementation scratches goes against moves the frame, the enhancement protects goes against.“Controls” namely controls the prop to drill the bottom, enhances the supports and protections system rigidity, adopts the plan should be floats the ledger wall the coal cleaning up to be clean, or defers to the ledger wall resistant to compression to enter the intensity, puts on shoes to the prop, when necessity may use measures and so on bottom millstone.“Steady” namely guaranteed the support the stability, prevented the crooked frame, loses face, ceases the accident the occurrence.Because ZWM grid support own on heavy under light, is the unstable structure, the support beam column position and the entire frame condition, puts the support the synthesis to be more nimble than, once therefore operates carelessly, the beam column position is unreasonable, supports and protects the resistance to be insufficient lightly, the heavy piece of damage support even appears loses face the accident, therefore the worker technology and the management level play the very major role in the support use, should strengthen the working surface production management, must control the good prop top-beam position, the relative relations and the phase, prevented the prop welcomes the mountain insufficiently, the support crooked, the top-beam flees the position and so on.
(5) This grid support both may with machine pick the coordination and to be possible to pick the coordination with the artillery, its initial investment only quite Yu Zong puts the support total investment 1/5 to 1/8 about, it has the volume small, the weight light, the structure simple, the installment and the transportation convenient, the operation easy and so on the merits, to returns to picks the geological condition complex and side the horn block section coal bed has the good nimble compatibility, therefore in the present coal mine economy universal difficult situation, it suits in the small coal mine.Uses the ZWM support to put correctly goes against the coal and takes the efficient measure, may display its nimble, the compatibility fully strong, the cost low, the semiautomation, the security and the high production highly effective merit.
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