外文翻譯--輸送帶技術(shù)的最新發(fā)展

1、<p><b>　　附錄</b></p><p><b>　　英文原文</b></p><p>　　Latest Developments in Belt Conveyor Technology</p><p>　　M. A. Alspaugh</p><p>　　Overland Con

2、veyor Co., Inc.</p><p>　　Presented at MINExpo 2004</p><p>　　Las Vegas, NV, USA</p><p>　　September 27, 2004</p><p><b>　　Abstract</b></p><p>　　Bu

3、lk material transportation requirements have continued to press the belt conveyor industry to carry higher tonnages over longer distances and more diverse routes. In order keep up, significant technology advances have be

4、en required in the field of system design, analysis and numerical simulation. Examples of complex conveying applications along with the numerical tools required to insure reliability and availability will be reviewed.&l

5、t;/p><p>　　Introduction</p><p>　　Although the title of this presentation indicates “new” developments in belt conveyor technology will be presented, most of the ideas and methods offered here have

6、been around for some time. We doubt any single piece of equipment or idea presented will be “new” to many of you. What is “new” are the significant and complex systems being built with mostly mature components ，what is a

7、lso “new” is the increasing ability to produce accurate computer simulations of system performance prior to the firs</p><p>　　As such, the main focus of this presentation will be the latest developments in c

8、omplex system design essential to properly engineer and optimize today’s long distance conveyance requirements. The four specific topics covered will be:</p><p>　　Energy Efficiency</p><p>　　Rout

9、e Optimization</p><p>　　Distributed Power</p><p>　　Analysis and Simulation</p><p>　　Energy Efficiency</p><p>　　Minimizing overall power consumption is a critical aspect

10、 of any project and belt conveyors are no different. Although belt conveyors have always been an efficient means of transporting large tonnages as compared to other transport methods, there are still various methods to r

11、educe power requirements on overland conveyors. The main resistances of a belt conveyor are made up of:</p><p>　　Idler Resistance</p><p>　　Rubber indentation due to idler support</p><

12、p>　　Material/Belt flexure due to sag being idlers</p><p><b>　　Alignment</b></p><p>　　These resistances plus miscellaneous secondary resistances and forces to over come gravity (li

13、ft) make up the required power to move the material.</p><p>　　In a typical in-plant conveyor of 400m length, power might be broken into its components as per Figure 1 with lift making up the largest single c

14、omponent but all friction forces making up the majority.</p><p>　　In a high incline conveyor such as an underground mine slope belt, power might be broken down as per Figure 2, with lift contributing a huge

15、majority. Since there is no way to reduce gravity forces, there are no means to significantly reduce power on high incline belts.</p><p>　　But in a long overland conveyor, power components will look much mor

16、e like Figure 3, with frictional components making up almost all the power. In this case, attention to the main resistances is essential.</p><p>　　The specifics of power calculation is beyond the scope of th

17、is paper but it is important to note that significant research has been done on all four areas of idlers, rubber indentation, alignment and material/belt flexure over the last few years. And although not everyone is in a

18、greement as to how to handle each specific area, it is generally well accepted that attention to these main resistances is necessary and important to overall project economics.</p><p>　　At the 2004 SME annua

19、l meeting, Walter Kung of MAN Takraf presented a paper titled “The Henderson Coarse Ore Conveying System- A Review of Commissioning, Start-up and Operation”2. This project was commissioned in December 1999 and consisted

20、 of a 24 km (3 flight) overland conveying system to replace the underground mine to mill rail haulage system.</p><p>　　The longest conveyor in this system (PC2) was 16.28 km in length with 475m of lift. The

21、most important system fact was that 50% of the operating power (~4000 kW at 1783 mt/h and 4.6 m/s) was required to turn an empty belt therefore power efficiency was critical. Very close attention was focused on the idler

22、s, belt cover rubber and alignment. One way to document relative differences in efficiency is to use the DIN 22101 standard definition of “equivalent friction factor- f” as a way to compare th</p><p>　　Route

23、 Optimization</p><p>　　Horizontal Adaptability</p><p>　　Of course the most efficient way to transport material from one point to the next is as directly as possible. But as we continue to transp

24、ort longer distances by conveyor, the possibility of conveying in a straight line is less and less likely as many natural and man-made obstacles exist. The first horizontally curved conveyors were installed many years ag

25、o, but today it seems just about every overland conveyor being installed has at least one horizontal change in direction. And today’s technolo</p><p>　　Figures 5 and 6 shows an overland conveyor transporting

26、 coal from the stockpile to the ship loader at the Tianjin China Port Authority installed this year. Designed by E.J.O’Donovan & Associates and built by Continental Conveyor Ltd of Australia, this 9 km overland carri

27、es 6000 mtph with 4x1500 kW drives installed.</p><p>　　The Wyodak Mine, located in the Powder River Basin of Wyoming, USA, is the oldest continuously operating coal mine in the US having recorded annual prod

28、uction since 1923. It currently utilizes an overland (Figure 7) from the new pit to the plant 756m long (2,482 ft) with a 700m (2,300 ft) horizontal radius. This proves a conveyor does not need to be extremely long to be

29、nefit from a horizontal turn.</p><p><b>　　Tunneling</b></p><p>　　Another industry that would not be able to use belt conveyors without the ability to negotiate horizontal curves is c

30、onstruction tunneling. Tunnels are being bore around the world for infrastructure such as waste water and transportation. The most efficient method of removing tunnel muck is by connecting an advancing conveyor to the ta

31、il of the tunnel boring machine. But these tunnels are seldom if ever straight. One example in Spain is the development of a 10.9m diameter tunnel under Barcelona </p><p>　　In another example, Frontier Kempe

32、r Construction is currently starting to bore 6.18 km (20,275 ft) of 3.6m (12 foot) diameter tunnel for the Metropolitan St. Louis (Missouri) Sewer District. The Baumgartner tunnel (Figure 10) will be equipped with a 6.1

33、km conveyor of 600mm wide belting with 4 intermediate drives.</p><p>　　Pipe Conveyors</p><p>　　And if conventional conveyors cannot negotiate the required radii, other variations of belt conveyo

34、r such as the Pipe Conveyor might be used.</p><p>　　In its simplest description, a pipe conveyor consists of a rubber conveyor belt rolled into a pipe shape with idler rolls. This fundamental design causes t

35、he transported material to be totaled enclosed by the belt which directly creates all the advantages. </p><p>　　The idlers constrain the belt on all sides allowing much tighter curves to be negotiated in any

36、 direction. The curves can be horizontal, vertical or combinations of both. A conventional conveyor has only gravity and friction between the belt and idlers to keep it within the conveyance path. </p><p>　　

37、Another benefit of pipe conveyor is dust and/or spillage can be reduced because the material is completely enclosed. A classic example where both environment and adaptability to path were particularly applicable was at t

38、he Skyline Mine in UT, USA (Figure 12). This 3.38 km (11,088 ft) Pipe Conveyor was installed by Thyssen Krupp Robins through a national forest and traversed 22horizontal and 45 vertical curves.</p><p>　　Mets

39、o Rope Conveyor</p><p>　　Another variation from conventional is the Metso Rope Conveyor (MRC) more commonly known as Cable Belt. This product is known for long distance conveying and it claims the longest si

40、ngle flight conveyor in the world at Worsley Alumina in Australia at 30.4 km. With Cable Belt, the driving tensions (ropes) and the carrying medium (belt) are separated (Figure 13).</p><p>　　Figure 15 shows

41、a 10.4 km Cable Belt with a 430m horizontal radius at Line Creek in Canada.</p><p>　　Vertical Adaptability</p><p>　　Sometimes material needs to be raised or lowered and the conventional conveyor

42、 is limited to incline angles around 16-18 degrees. But again non-traditional variations of belt conveyors have been quite successful at increased angles as well as straight up.</p><p>　　High Angle Conveyor

43、(HAC)</p><p>　　The first example manufactured by Continental Conveyor & Equipment Co. uses conventional conveyor components in a non-conventional way (Figure 16). The concept is known as a sandwich conve

44、yor as the material is carried between two belts.</p><p>　　Continental’s 100th installation of the HAC? was a unique shiftable installation at Mexican de Canenea’s heap leach pad (Figure 17).</p><

45、p>　　Pocketlift</p><p>　　The second example shows a non-traditional belt construction which can be used to convey vertically (Figure 18).</p><p>　　This Metso Pocketlift belt was installed by F

46、rontier Kemper Constructors at the Pattiki 2 Mine of White County Coal in 2001 (Figure 19). It currently lifts 1,818 mtph of run-of-mine coal up 273 m (895 ft). </p><p>　　Distributed Power</p><p&g

47、t;　　One of the most interesting developments in technology in the recent past has been the distribution of power along the conveyor path. It has not been uncommon to see drives positioned at the head and tail ends of lon

48、g conveyors and let the tail drive do the work of pulling the belt back along the return run of the conveyor. But now that idea has expanded to allow designers to position drive power wherever it is most needed. </p&g

49、t;<p>　　The idea of distributing power in multiple locations on a belt conveyor has been around for a long time. The first application in the USA was installed at Kaiser Coal in 1974. It was shortly thereafter tha

50、t underground coal mining began consolidating and longwall mines began to realize tremendous growth in output. Mining equipment efficiencies and capabilities were improving dramatically. Miners were looking for ways to i

51、ncrease the size of mining blocks in order to decrease the percentage of id</p><p>　　When panel lengths were increased, conveyance concerns began to appear. The power and belt strengths needed for these leng

52、ths approaching 4 -5 km were much larger than had ever been used underground before. Problems included the large size of high power drives not to mention being able to handle and move them around. And, although belting t

53、echnology could handle the increased strength requirements, it meant moving to steel reinforced belting that was much heavier and harder to handle and more im</p><p>　　Today, intermediate drive technology is

54、 very well accepted and widely used in underground coal mining. Many mines around the world have incorporated it into their current and future mine plans to increase the efficiency of their overall mining operations. <

55、;/p><p>　　The tension diagram in Figure 20 shows the simple principal and most significant benefit of intermediate belt conveyor drives. This flat, head driven conveyor has a simple belt tension distribution as

56、 shown in black. Although the average belt tension during each cycle is only about 40% of the peak value, all the belting must be sized for the maximum. The large drop in the black line at the head pulley represents the

57、total torque or power required to run the conveyor. </p><p>　　By splitting the power into two locations (red line), the maximum belt tension is reduced by almost 40% while the total power requirement remains

58、 virtually the same. A much smaller belt can be used and smaller individual power units can be used. To extend the example further, a second intermediate drive is added (green line) and the peak belt tension drops furthe

59、r. </p><p><b>　　中文譯文</b></p><p>　　輸送帶技術(shù)的最新發(fā)展</p><p>　　M. A. Alspaugh</p><p>　　Overland Conveyor Co., Inc.</p><p>　　Presented at MINExpo 2004<

60、;/p><p>　　Las Vegas, NV, USA</p><p>　　September 27, 2004</p><p><b>　　摘要</b></p><p>　　大量的物質(zhì)運(yùn)輸需求在促使帶式輸送機(jī)繼續(xù)朝大運(yùn)量、長(zhǎng)距離、多路徑發(fā)展。為滿足生產(chǎn)力的發(fā)展，在系統(tǒng)設(shè)計(jì)、分析和數(shù)值模擬等領(lǐng)域需要更多重要的技術(shù)革新。在這

61、里我們將回顧一些復(fù)雜的、利用數(shù)學(xué)工具來保證其可靠性和適用性的實(shí)例。</p><p><b>　　緒論</b></p><p>　　盡管這篇文章的標(biāo)題指出將會(huì)展現(xiàn)給大家?guī)捷斔蜋C(jī)“新的”發(fā)展技術(shù)，但當(dāng)中的大多數(shù)的思想和方法早已經(jīng)四處流傳了?？峙缕渲腥魏我粋€(gè)的簡(jiǎn)單設(shè)備或想法對(duì)大多數(shù)人都不是“新的”。 所謂“新的”東西就是一個(gè)在成熟的條件下建立的復(fù)雜、重要的系統(tǒng)，是在一個(gè)系

62、統(tǒng)檢測(cè)(試運(yùn)轉(zhuǎn))之前對(duì)系統(tǒng)性能的精確計(jì)算機(jī)模擬能力的提高。</p><p>　　因而，我們討論的主要焦點(diǎn)是，復(fù)雜帶式輸送機(jī)系統(tǒng)設(shè)計(jì)的最新發(fā)展，以及針對(duì)長(zhǎng)距離運(yùn)輸?shù)脑O(shè)計(jì)和優(yōu)化。</p><p>　　四個(gè)被涵蓋的主題是：</p><p><b>　　能量利用效率</b></p><p><b>　　線路優(yōu)化<

63、/b></p><p><b>　　動(dòng)力分配</b></p><p><b>　　分析和仿真</b></p><p><b>　　能量利用率</b></p><p>　　將總耗電量降到最小不論對(duì)于帶式輸送機(jī)還是其它項(xiàng)目都是問題的關(guān)鍵。盡管地面大運(yùn)量運(yùn)輸時(shí)利用帶式輸送機(jī)總是

64、效率很高的手段，還是有很多方法來降低其能量需求。帶式輸送機(jī)的運(yùn)行阻力由以下幾部分組成：</p><p><b>　　托輥?zhàn)枇?lt;/b></p><p><b>　　膠帶與托輥架擠壓</b></p><p><b>　　膠帶垂度的影響</b></p><p><b>　　

65、調(diào)心托輥的影響</b></p><p>　　這些阻力加上其它各種次要的阻力以及用來克服重力的升力，就形成所需總共的動(dòng)力。</p><p>　　在一條 400 m 長(zhǎng)度的典型廠內(nèi)輸送機(jī)中，動(dòng)力可能依照?qǐng)D 1 被分成幾部分，其中運(yùn)輸提升所需的動(dòng)力是其中最大的一塊，而所有摩擦阻力又占它的了多半數(shù)。</p><p>　　對(duì)于大傾角輸送機(jī), 例如煤礦井下帶式輸送機(jī)

66、,動(dòng)力可能依照?qǐng)D 2 所示分配，其中用于提升的動(dòng)力占了極大的一部分。 因?yàn)闆]有方法減少重力的影響，所以就沒有方法能顯著地減少在大傾角帶式輸送機(jī)上的動(dòng)力消耗。</p><p>　　但是在長(zhǎng)距離地面輸送機(jī)中，動(dòng)力組成的幾個(gè)部分就與圖3所示較為相似，動(dòng)力幾乎全都消耗在摩擦阻力上。所以在這種情況下應(yīng)特別關(guān)注帶式輸送機(jī)的主要阻力。</p><p>　　有關(guān)詳細(xì)的動(dòng)力計(jì)算在這里不做贅述，但值得關(guān)注的是

67、，對(duì)于托輥、膠帶、調(diào)心、物料/膠帶彎曲這四方面近年來已完成許多有意義的研究工作。</p><p>　　對(duì)于各個(gè)具體方面的問題如何處理，雖然仁者見仁、智者見智，但通常大家都認(rèn)為，將著眼點(diǎn)放在主要阻力上對(duì)整個(gè)工程的經(jīng)濟(jì)性是重要且必需的。</p><p>　　在 2004 SME 年會(huì)上,MAN Takraf 的Walter·Kung 介紹了一篇題為“亨德森粗礦石運(yùn)輸系統(tǒng)——運(yùn)行、啟動(dòng)

68、、操作評(píng)估”的論文。 這個(gè)工程于 1999 年12月啟動(dòng)，是由一條 24公里(3段)的地面輸送系統(tǒng)來代替地下挖掘碾磨軌道拖運(yùn)系統(tǒng)。</p><p>　　這個(gè)系統(tǒng) (PC2) 中的最長(zhǎng)運(yùn)送機(jī)長(zhǎng)16.28 公里，提升高度475 m 。系統(tǒng)最重要的工況是使帶空載運(yùn)轉(zhuǎn)時(shí)需要50% 的額定功率(約4000 千瓦，在1783 mtph 和 4.6 m/s時(shí))，這時(shí)功率效率達(dá)到臨界值。要把注意力集中在托輥, 覆蓋膠和調(diào)心上。

69、一種判斷效率上的相對(duì)差異的方法是使用 DIN(德國(guó)工業(yè)標(biāo)準(zhǔn)) 22101 標(biāo)準(zhǔn)定義中的" 等效磨擦因數(shù)—f" ，就如比較各個(gè)主要阻力的相對(duì)差異的方法一樣。過去，用于設(shè)計(jì)輸送機(jī)的典型f值DIN規(guī)定為0.016左右，但 MAN Takraf 估計(jì)以他們對(duì)動(dòng)力情況的了解，允許他們將f值降低30％，達(dá)到0.011。該值的減少會(huì)給設(shè)備的基本投資節(jié)省一筆不小的開支。試運(yùn)行后，6次換檔的實(shí)測(cè)結(jié)果顯示，f值為0.0075，或是更小，

70、比期望值低30％左右。 Kung說，只將f從期望值減少每年就會(huì)節(jié)省電費(fèi)$100,000。</p><p><b>　　路徑最優(yōu)化</b></p><p><b>　　水平運(yùn)輸?shù)倪m用性</b></p><p>　　當(dāng)然，從一處到另一處運(yùn)送物料最有效的方法是盡可能直接地運(yùn)輸。但是當(dāng)我們用輸送機(jī)長(zhǎng)距離連續(xù)輸送時(shí),由于人為或自然的

71、原因，能在直線運(yùn)輸?shù)目赡苄陨僦稚?。第一臺(tái)水平曲線式輸送機(jī)的安裝在數(shù)年以前，但是今天幾乎每一臺(tái)安裝的地面輸送機(jī)都至少有一個(gè)水平方向的變化。而且今天的技術(shù)允許設(shè)計(jì)者相對(duì)容易地調(diào)整這些曲線。 </p><p>　　圖 5 和 6 顯示在中國(guó)天津港務(wù)局，一條今年安裝的地面帶式輸送機(jī)正將煤從倉庫運(yùn)送到裝船機(jī)。 這條9 公里的帶式輸送機(jī)由 E.J.O'Donovan與 Associates 設(shè)計(jì)、澳大利亞的Cont

72、inental Conveyor 公司制造，運(yùn)量為6000 mtph ，驅(qū)動(dòng)功率為4 x1500 kW。</p><p>　　位于美國(guó)懷俄明州Powder River 盆地的Wyodak礦井,是自1923年美國(guó)有年產(chǎn)量記錄以來最老的煤礦，而且如今還在不斷地產(chǎn)煤。它現(xiàn)在利用一臺(tái)水平半徑為700 m(2,300 ft) 地面帶式輸送機(jī)(圖 7) ，新煤坑離廠 756 m (2,482 英尺)。這證明受益于水平轉(zhuǎn)向，帶

73、式輸送機(jī)不需要非常的長(zhǎng)。</p><p><b>　　隧道</b></p><p>　　如果沒有水平曲線，建造隧道就不能利用帶式輸送機(jī)了。全世界都在挖掘隧道，以作為下水道或是運(yùn)輸?shù)然A(chǔ)設(shè)施。將挖掘隧道時(shí)產(chǎn)生的棄渣運(yùn)出，最有效的方法是在隧道鉆機(jī)的尾部連接一個(gè)推進(jìn)式帶式輸送機(jī)。但很少有隧道是筆直的。</p><p>　　例如，西班牙巴塞羅那的地下有

74、一條直徑為 10.9 m 隧道，它是倫敦地鐵系統(tǒng)的延伸。Continental Conveyor 公司安裝了如圖 8 、9所示的第一個(gè)4.7 公里輸送機(jī)，而且最近已經(jīng)接受負(fù)責(zé)安裝第二個(gè) 8.39 公里的輸送機(jī)。</p><p>　　Frontier Kemper Construction 正開始為Metropolitan St. Louis (位于密蘇里州)的排水區(qū)挖掘一條6.18 公里(20,275 英尺) 長(zhǎng)

75、、3.6 m(12英尺)寬的隧道。 這個(gè)名為Baumgartner 的隧道(圖 10) 將會(huì)裝備一個(gè)長(zhǎng)6.1 公里、帶寬600 毫米、具有4個(gè)中間傳動(dòng)裝置的帶式輸送機(jī)。</p><p><b>　　管狀輸送機(jī)</b></p><p>　　如果傳統(tǒng)的輸送機(jī)不能夠滿足半徑的要求, 就可用其他帶式運(yùn)送機(jī)的變體例如管狀帶式輸送機(jī)。</p><p>　　

76、簡(jiǎn)單的描述一下，一個(gè)管狀輸送機(jī)由一個(gè)卷成桶狀的傳送帶與輥?zhàn)咏M成。這種很基本的設(shè)計(jì)方法可以使物料被輸送帶完全包起來，直接產(chǎn)生較高的效益。</p><p>　　托輥在各方向約束著膠帶，就允許膠帶朝各個(gè)方向較大地彎曲。 曲線可能是水平的，垂直的或二者的結(jié)合。而傳統(tǒng)的輸送機(jī)只能靠膠帶和托輥的重力和摩擦力保證運(yùn)輸路徑。</p><p>　　管狀輸送機(jī)的另一個(gè)好處是能減少粉塵及灑漏，因?yàn)槲锪鲜峭耆环?/p>

77、閉的。這有一個(gè)經(jīng)典的例子，在美國(guó)猶他州的Skyline 礦中(圖 12)，路徑與周圍環(huán)境很好的適應(yīng). 這條3.38 公里(11,088 英尺)長(zhǎng)的管狀輸送機(jī)是由ThyssenKrupp Robins 安裝，穿過一個(gè)國(guó)家森林，而且中間水平換向22次、豎直換向45次。</p><p>　　Metso鋼繩輸送機(jī)</p><p>　　Metso鋼繩輸送機(jī)(MRC)是另一種從傳統(tǒng)型變化而來輸送機(jī)，人

78、們一般稱它為鋼繩牽引輸送機(jī)。這一產(chǎn)品以長(zhǎng)距離輸送聞名，世界最長(zhǎng)的刮板式輸送機(jī)在澳大利亞的 Worsley Alumina ，長(zhǎng)度為30.4千米。它的牽引體與承載體是分開的(圖 13)。</p><p><b>　　垂直的適用性</b></p><p>　　有時(shí)物質(zhì)的需要被升起或降落，而常規(guī)的輸送機(jī)的傾角被限制在16-18 度。 但是帶式輸送機(jī)的再一次突破常規(guī)的變化使帶

79、式輸送機(jī)可以成功地增大傾角，甚至可以垂直輸送。</p><p>　　大傾角輸送機(jī) (HAC)</p><p>　　大傾角輸送機(jī)的第一臺(tái)樣機(jī)由Continental Conveyor & Equipment Co.制造出來，它用的是常規(guī)的部件、非常規(guī)的手段(圖16)。人們認(rèn)為采用這種方法，物料夾在兩層輸送帶之間，整個(gè)輸送機(jī)看起來就像一個(gè)大的三明治。</p><p&

80、gt;　　Continental公司安裝制造的第100臺(tái)大傾角輸送機(jī)是一種獨(dú)特的、可拆移的輸送機(jī)，它位于墨西哥的Mexican de Canenea 矸石過濾堆(圖 17).</p><p>　　Pocketlift</p><p>　　圖 18展示另一條非常規(guī)設(shè)計(jì)的輸送帶，它能用來垂直運(yùn)輸。這一條 Metso Pocketlift 輸送帶由Frontier Kemper Construc

81、tors 于2001年安裝在 White County 的 Pattiki 2號(hào)井(圖19)，現(xiàn)在它的運(yùn)量是1,818 mtph，可將煤提升 273 m(895 英尺) 。</p><p><b>　　動(dòng)力分配</b></p><p>　　當(dāng)下有關(guān)帶式輸送機(jī)新技術(shù)的研究，最熱門的內(nèi)容應(yīng)該數(shù)整個(gè)路線的動(dòng)力分配問題了。將驅(qū)動(dòng)裝置布置在輸送機(jī)頭部和尾部，然后只讓尾部驅(qū)動(dòng)裝置

82、負(fù)責(zé)拉回輸送帶，這對(duì)于長(zhǎng)距離帶式輸送機(jī)是不常見的。但現(xiàn)在的設(shè)計(jì)思想已發(fā)展成為允許設(shè)計(jì)者將動(dòng)力布置在最需要的地方。</p><p>　　將動(dòng)力布置在帶式輸送機(jī)的多個(gè)部位的想法很早以前就有了。第一次在美國(guó)應(yīng)用是在1974年，Kaiser煤礦。不久，地下礦井開始合并，長(zhǎng)壁開采的煤礦的產(chǎn)量得到極大提高。其中采礦設(shè)備效率和性能的提高是非常引人注目的。礦工們正在尋找方法增大采區(qū)，以減少將采煤設(shè)備從一個(gè)采區(qū)搬到另一個(gè)采區(qū)所花費(fèi)

83、的時(shí)間。這樣，煤區(qū)表面寬度與長(zhǎng)度也不斷增加。</p><p>　　當(dāng)矩形采煤區(qū)的長(zhǎng)度增加時(shí)，就應(yīng)注意一下運(yùn)輸條件。當(dāng)長(zhǎng)度增加到4～5千米時(shí)，輸送機(jī)對(duì)動(dòng)力與膠帶強(qiáng)度的需要增加到前所未有的程度。問題包括：如此大尺寸的大功率驅(qū)動(dòng)裝置別說搬運(yùn)了，即使皮帶(傳動(dòng))裝置技術(shù)可以滿足增加的強(qiáng)度需求,也意味著要費(fèi)很大勁來回搬運(yùn)傳動(dòng)裝置，更重要的是要用硫化接頭。由于長(zhǎng)壁開采區(qū)的輸送機(jī)需要經(jīng)常改變長(zhǎng)度，礦工們總是不停地從系統(tǒng)中增加或

84、取去皮帶傳動(dòng)裝置的托輥。時(shí)間浪費(fèi)更加嚴(yán)重。但現(xiàn)在需要超越了風(fēng)險(xiǎn)，而且廣泛采用中間傳動(dòng)裝置限制了皮帶中的張力過大，并允許采用纖維帶。</p><p>　　今天, 中間驅(qū)動(dòng)技術(shù)已被人們接受而且廣泛地應(yīng)用于地下礦井。世界上多數(shù)礦井經(jīng)將它納入他們當(dāng)前和未來的開采計(jì)劃以增加他們所有的開采工作的效率。</p><p>　　圖 20 中的張力圖簡(jiǎn)單地說明了帶式輸送機(jī)中間傳動(dòng)裝置的主要優(yōu)點(diǎn)。頭部驅(qū)動(dòng)輸送機(jī)