【正文】 附錄A Comparison of Soft Start Mechanisms for Mining Belt ConveyorsMichael L. Nave, .CONSOL Inc.1800 Washington Road Pittsburgh, PA 15241 Belt Conveyors are an important method for transportation of bulk materials in the mining industry. The control of the application of the starting torque from the belt drive system to the belt fabric affects the performance, life cost, and reliability of the conveyor. This paper examines applications of each starting method within the coal mining industry.INTRODUCTIONThe force required to move a belt conveyor must be transmitted by the drive pulley via friction between the drive pulley and the belt fabric. In order to transmit power there must be a difference in the belt tension as it approaches and leaves the drive pulley. These conditions are true for steady state running, starting, and stopping. Traditionally, belt designs are based on static calculations of running forces. Since starting and stopping are not examined in detail, safety factors are applied to static loadings (Harrison, 1987). This paper will primarily address the starting or acceleration duty of the conveyor. The belt designer must control starting acceleration to prevent excessive tension in the belt fabric and forces in the belt drive system (Suttees, 1986). High acceleration forces can adversely affect the belt fabric, belt splices, drive pulleys, idler pulleys, shafts, bearings, speed reducers, and couplings. Uncontrolled acceleration forces can cause belt conveyor system performance problems with vertical curves, excessive belt takeup movement, loss of drive pulley friction, spillage of materials, and festooning of the belt fabric. The belt designer is confronted with two problems, The belt drive system must produce a minimum torque powerful enough to start the conveyor, and controlled such that the acceleration forces are within safe limits. Smooth starting of the conveyor can be acplished by the use of drive torque control equipment, either mechanical or electrical, or a bination of the two (CEM, 1979).SOFT START MECHANISM EVALUATION CRITERIONWhat is the best belt conveyor drive system? The answer depends on many variables. The best system is one that provides acceptable control for starting, running, and stopping at a reasonable cost and with high reliability (Lewdly and Sugarcane, 1978). Belt Drive System For the purposes of this paper we will assume that belt conveyors are almost always driven by electrical prime movers (Goodyear Tire and Rubber, 1982). The belt drive system shall consist of multiple ponents including the electrical prime mover, the electrical motor starter with control system, the motor coupling, the speed reducer, the low speed coupling, the belt drive pulley, and the pulley brake or hold back (Cur, 1986). It is important that the belt designer examine the applicability of each system ponent to the particular application. For the purpose of this paper, we will assumethat all drive system ponents are located in the fresh air, nonpermissible, areas of the mine, or in nonhazardous, National Electrical Code, Article 500 explosionproof, areas of the surface of the mine. Belt Drive Component Attributes Size.Certain drive ponents are available and practical in different size ranges. For this discussion,。在此表示衷心的感謝， 同時也感謝所有關心、支持和幫助過我的老師、同學、和朋友。參 考 文 獻[1] Oehmen H. 帶式輸送機的設計與運轉(zhuǎn)[J] . 起重運輸機械，1982[2] 徐寄容編. ，1994[3] 孫可文著. ，1991[4] 楊篡興. 膠帶輸送機結構\原理與計算(上冊).北京:煤炭工業(yè)出版社，1983[5] 黃萬吉編. ：東北工學院出版社，1900[6] 于學謙，方佳雨編. ：中國礦業(yè)大學出版社，1989[7] 黃松元等. 輸送帶粘彈性力學特性的研究連續(xù)輸送技術. 中國礦業(yè)大學出版社，1991[8] 國外長距離膠帶輸送機編寫組. :煤炭工業(yè)出版社，1987[9] 李光布. ，:[10] 趙玉文，李云海. ，2004：1[11] 宋偉剛. ，2007：[12] 于巖，李維堅. ，1998：[13] 程居山. ，1997：[14] 陳道南. ，2005：[15] 黃萬吉. 礦山運輸機械設計 東北工學院出版社 [16] Nordell L K. The channel 20 km overland A Flagship of Mod2ern Belt Conveyor Technology [ J ] . Bulk Solids Handling，1991 , 11 (4) : 781 —792[17] Lodewijks G. Non Linear Dynamics of Belt Conveyor Systems. Bulk Solids Handling，1997 ， 17 (1) : 57 —67 [18] Singh ..The Role of Drive System Technology in Maximizing the Performance and Economics of Long Belt Conveyors [J].Bulk Solids Handli8ng，1994，14（4），695－670[19] Harrison A. Simulation of Conveyor Dynamics，bulk solids handling，1996，1[20] Pritchard . Hesterman . Elastic Dynamics in an overland Belt Conveyor Modelled by Receptances. bulk solids handling，2000，4[21] Nordell L K. The channel 20 km overland A Flagship of Mod2ern Belt Conveyor Technology [ J ] . Bulk Solids Handling ，1991 , 11 (4) : 781 —792[22] Lodewijks G. Non Linear Dynamics of Belt Conveyor Systems. Bulk Solids Handling ， 1997 , 17 (1) : 57 —67 [23] Singh ..The Role of Drive System Technology in Maximizing the Performance and Economics of Long Belt Conveyors [J].Bulk Solids Handli8ng，1994，14（4），695－670[24] Harrison A. Simulation of Conveyor Dynamics，bulk solids handling，1996，1[25] Pritchard . Hesterman . Elastic Dynamics in an overland Belt Conveyor Modelled by Receptances. bulk solids handling，2000，4[26] Belt conveyor technology(part Ⅲ).trans tech publications，200027] Otrebski .. Attempts to Improve Startup Performance of Conveyors with booster Solid Handling，1993,13(4),737~739[28] Lodewijks G.. dynamics of belt systems: Dortoral Thesis. Delft University of Technology, Netherland，1996致 謝本論文是在 等老師細心指導和熱心幫助下完成的,在此我謹懷誠摯的心情向于老師，郝老師致以崇高的敬意和深深的謝意！感謝她這段時間對我們的關心和幫助；感謝她給我們提供了這么好的實習和設計環(huán)境；于老師他淵博的學識、嚴謹?shù)闹螌W態(tài)度、活躍的學術思想、積極進取的人生態(tài)度和誨人不倦的學者風范我受益終生，同時也使我明白了做事情就應該認認真真、扎扎實實，不能有一絲的疏忽和馬虎的道理，對我以后人生的發(fā)展奠定了堅實的基礎。當系統(tǒng)中出現(xiàn)下列情況之一時，沿線電鈴將報警。在此方式下可以通過操作手動控制方式下的指令開關按鈕和開關來起動、停止有關設備。在手動方式下，除上述故障與控制系統(tǒng)存在閉鎖急停關系外，其他保護或故障無停車作用，因此上述故障司機要注意觀察控制臺版面上的有關指示，以便在故障下實施停車。至此，控制系統(tǒng)具備了手動工作方式的條件，這時可操作手動控制方式指令下的相關按鈕完成輸送機的起動。①人為按動停車按鈕②打滑故障時 自動工作方式下正常停車控制程序框圖（3）緊急停車當系統(tǒng)出現(xiàn)下列情況之一時，控制系統(tǒng)進入緊急停車程序。司機可直接按動自動控制指令下的起動按鈕使輸送機自動起動投入正常運行。油壓調(diào)節(jié)：手動控制方式下，用于液粘調(diào)速器控制油壓的增加或減小的調(diào)節(jié)，以實現(xiàn)加速或減速控制。起動、停止指令：用于對輸送機實施開車與停車的控制。潤滑泵是否開啟。起動用于計時器進行累積計時的開始；停止用于計時器的停止；清零用