外文翻译--斗轮取料机的性能【中英文文献译文】
外文翻译-斗轮取料机的性能【中英文文献译文】,中英文文献译文,外文,翻译,斗轮取料机,性能,机能,中英文,文献,译文
Full Text :COPYRIGHT 2008 Reed Business Information Ltd. All Rights Reserved.Jamie Wade With the help of a lifting solutions company engineers at ThyssenKrupp reduced the assembly time of building an urgently needed big bucket wheel reclaimer. *Rod Lindblade writes Increasing the capacity of Australias big coal shipping ports is vital - sighting the huge queues of ships waiting weeks and weeks to load is totally unacceptable to many people and does not reflect the ability of innovative, energetic, can do Australians to get things done - on time. However, an interesting example of Australian ingenuity and getting things done on time recently emerged at the Hay Point Coal Terminal, 30 km south of Mackay on the central Queensland coast. It was a procedure that reduced the assembly time of an urgently needed big bucket wheel reclaimer and a procedure that saved significant construction time and dollars, said Jim Carr, general manager business development and customer solutions at Boom Logistics when initially discussing the project with Australian Mining. The engineers at ThyssenKrupp, the company selected to design and build the new reclaimer, believed a better and faster way could be found to build the main boom, finish it by adding all components and then attaching the boom to the Stacker / Reclaimer in the completed state. Having developed a revised way of assembling their new machine, ThyssenKrupp engineers then called in Boom Logistics Heavy Haulage Division to see if their idea could be made to work, and if Boom had the unique equipment required for this procedure. Previously, with this sort of project, the building process would involve the 60 m long boom being progressively assembled after attaching the base unit of the boom to the machine, explained Peter Chapman of ThyssenKrupp. The alternative process that the ThyssenKrupp engineers visualised was one of building the boom of the reclaimer at ground level and, when more-or-less completed, moving it close to the machine and then lifting it up and into position for attaching to the slewing deck. We chose to discuss the process with the heavy haulage experts at Boom Logistics, said Chapman. They were able to confirm that the proposed process could be carried out and, importantly, they had the equipment to do the job, he added. The process was a push, pull, carry and lift process, said Darren Jones of Mackay depot of Boom Logistics Heavy Haulage Division. The 205 tonne boom of the reclaimer was sitting on stools at a height, just over 2.4 m above ground. As can be seen in the accompanying photo, we located our low profile prime mover and float under the far end of the boom, and we could do that as the prime mover, adapted from a CLR Mack chassis and powered by a 210 hp engine, is only 1.2 m in overall height. Then, with a lift mechanism on our float we were able to lift the reclaimers boom up off the stands with the 125 tonne weight of that end of the boom then carried by the float, explained Darren. The crew were then able to bring in the big full size 550 hp Mack Titan prime mover with a specially engineered front mounted drawbar and connect it to the float. With the other end of the reclaimers boom to be lifted by a Manitowoc 200 tonne ringer crane, all was ready for the lift and shift. First, the end of the boom to be lifted by the ringer crane was raised 12 m, being the final height for attaching to the slew deck before the moving process commenced. The crane, with the load suspended, was in free slew mode, so the reclaimer boom could be moved forward towards the machine. With ringer crane holding up the reclaimers boom, as well as slewing its own boom and the low profile prime mover - aided by the push from the big Mack -we were able to move forward 1 m at a time. Then, as we neared the machine, extreme care was exercised. The reclaimers boom was inched into position for attaching to the mounting point. Absolute precision was required in order to insert the 180 kg pins through the bearings in the boom, added Darren. With this process, using Booms heavy haulage equipment and crew, ThyssenKrupp were able to make considerable savings and more importantly, reduce the risk of working at height, when compared with the earlier technique of fitting out the reclaimer boom when it was located up in the air nearer its working position and attached to the machine. First saving was the need for only one large crane, in lieu of two. Second saving was eliminating many working at height issues. And third saving was completing the job in far shorter time - about six weeks shorter. That translates to far less waiting time for the huge fleet of coal carrying ships anchored off Hay Point, all at a huge cost. Australians are can do people, as has been seen many times in the resources sector. Just let them get on with the job. *Written by Rod Lind blade for Boom Logistics Ltd . For more information, call Rod at Northfield Communications - Business-to-Business advertising and journalism on 03 9681 9585, or email rodnorthcom.net.au. Jim Carr Boom Logistics jcarrboomlogistics.com.au www.boomlogistics.com.au全文: 2008年Reed商业信息有限公司保留所有权利。Jamie Wade在蒂森克虏伯公司中负责起重解决方案的工程师们的帮助下,减少了建立大型斗轮取料机的装配时间,Rod Lind blade写道。增加澳大利亚煤炭运输港口吞吐能力的任务迫在眉睫船舶长时间等待装载货物的状况对大多数人是无法接受的,这事与澳大利亚人做任何事都很准时的原则相违背。然而,一个有趣例子最近出现在马偕中央昆士兰海岸以南30公里处的干草点煤码头,这个例子反映了澳大利亚人的聪明才智和做事按时的原则。“这是一个关于减少斗轮取料机装配时间的程序,并且能节省重要的时间和金钱”,在与澳大利亚矿业部门初步讨论这个项目时,负责业务发展和客户解决方案经理Jim Carr说。蒂森克虏伯公司设计和建造了新的取料机,并且该公司的工程师们相信可以找到更快更好的方法来建立主臂,然后把所有组件都装在主臂上,最后再把主臂安装在已制造完成的堆取料机上。蒂森克虏伯公司制订了组装新机器的新方式,然后工程师们在物流重型运输公司做试验,验证他们的想法是否能付诸实际运行,并测试主臂是否需要一个独特的设备来支持程序的运行。“以前在进行此类工程时,从主臂的基础部分依附到主机器还需要60米长的臂来进行逐步组装”,蒂森克虏伯的Peter Chapman解释道。蒂森克虏伯工程师们设想的方法是在地面建造取料机的主臂,并在差不多完成的时候把主臂移近机器,然后把它举至能依附在回转甲板的位置。“我们选择与负责物流的重型运输专家讨论这个工程”,Chapman说道。“他们能够判断拟议的进程是否可行,重要的是他们有设备去做这项工作”,Chapman说道。“这是一个推、拉、执行和解除的过程”,麦凯车厂物流重型运输司的Darren Jones说道。“205吨重的取料机主臂安装在离地只有2.4米高的基座上。然后,我们能够把125吨重的主臂举起并搬动“,Darren解释道。当取料机主臂的一端被200的吨林格马尼托瓦克起重机举起的时候,所有运作都已准备好。首先,主臂一端被林格起重机举升到12米高度,这是在移动进程开始之前,为了使主臂能依附到回转甲板所选的最终位置。吊车暂停在自由转换模式,所以主臂可移至主机器。在林格起重机举着取料机主臂时,回转主臂计算机辅助控制我们能使主臂向前推动1米。然后,当我们接近机器时,要小心控制,取料机的主臂微升到安装点的位置。绝对精度要求能使重达180公斤的插脚插入主臂的轴承,Darren说道。在这一过程中,利用重型运输设备和操纵人员,蒂森克虏伯公司能得到相当大的节省,更重要的是,相比先前的技术装备,降低了高空作业的危险性 。一是只需要一台大型起重机,以替代两个。二是消除了许多高空工作问题。三是缩短了工作完成的时间约6个星期。这就解释了为什么能够减少在海伊停泊点上进行煤炭装载所需的时间。澳大利亚人是“无所不能”的人民,并在实际工程中屡见不鲜。只要放手让它们做。Jim CarrBoom LogisticsBUCKET WHEEL RECLAIMERSAUTHOR: MR. W KNAPPEMAN TAKRAF Frdertechnik GmbHPerformance of Bucket Wheel Reclaimers(Method of Calculation in Principle)A: IntroductionThe objective of the following is to consider bucket wheel reclaimers with a slewable boom moving on a rail track adjacent to or between stockpiles.(Picture 1)Picture 1 Stockpiles with BW ReclaimerThe reclaiming capacity of the bucket wheel is a characteristic quantity for which a number of definitions are used. These will be explained further in this summary.The most interesting factor for the owner of bucket wheel reclaimers is, however, the performance of the machine. If a power station has to be supplied with coal, it is important to know how much coal will, for example, reach the coal fire silos in 4 hours. If a ship has to be loaded, how long will it take to load the ship? The term nominal capacity will not provide adequate information to satisfactorily reply to these questions.The following is an introduction to the definitions of reclaiming quantities and to the interacting and influencing factors for determining the average reclaiming capacities to be expected with various shapes of stockpiles and reclaiming methods.B: Definition of Reclaiming Capacities at the Bucket Wheel1. GeneralThe bucket wheel speed is assumed as a constant referred to a certain handled material with defined density.The aim is to have constantly full buckets. The bucket filling is a product of the cutting height, the cutting depth and the cutting width.Bucket volume VB = CH x CD x CW (m)The reclaiming capacity is the product of bucket volume and number of fills.Reclaiming capacity Q = VB x f x ND (m/h)2. Theoretical or Design CapacityThe theoretical reclaiming capacity is the capacity for which the bucket wheel is sized, irrespective of the grain and viscosity of the handled material and the position (inclination) of the bucket wheel.To determine the theoretical capacity, the volume of the bucket with the corresponding proportion of the cell or of the annular space is calculated with the water cross-section, which signifies the filling factor f = 1.3. Maximum CapacityThe maximum reclaiming capacity is of interest for the subsequent belt conveyors in order to avoid overfilling.The maximum reclaiming capacity takes the most favorable conditions into account, but these are not necessarily always present.The filling factor f may in this case be up to 1.2 and takes into account a filled annular space (cell) with additional overload on the buckets.4. Nominal CapacityThe nominal capacity is the actual bucket wheel reclaiming amount to be expected. In this case, the available filling capacity of the buckets is examined which will vary depending on whether pellets, HBI or power station coal are to be filled. The grain size is also important as well as the inclination of the bucket wheel.The filling factor is corrected here to the design capacity. The correction is carried out basing on the experience of the manufacturer in close agreement with the owners.C: Performance of the Bucket Wheel ReclaimerThe performance of a bucket wheel reclaimer is determined not only by the nominal capacity but is also influenced by other factors, such as described hereunder.Direct influencesShape and size of the stockpileNumber of benches to be reclaimedPrepared shape of stockpile for initial cut and endTravel, slew and hoist speeds of the reclaimerAccelerations of the movementsReclaiming methodIndirect influencesMaximum reclaiming amount must be restricted for other reasonsInterruptions in operationStarting and braking of the conveyor systemWeather influencesEnclosed particles in the material which have to be removed by manuallyCaving in of stockpilesIntolerable stockpile construction deviationsFrom the above list it is apparent that only the direct influences can be accounted for when performing the calculation.The indirect influences are dependent on the type and design of the whole conveyor system and on the consumer and cannot be further looked into at this stage.D: Shape of stockpile and block heightsBucket wheel reclaimers are familiar at triangular piles, trapezoidal piles and at trapezoidal piles with side banks. (Picture 2)Picture 2 Stockpile ShapesThe number of blocks are selected in accordance with the height of the stockpile and the diameter of the bucket wheel. The height of cut should not exceed 0.65 x bucket wheel diameter as otherwise there is a risk of undercutting and of the stockpile caving in.E: Speeds and accelerationsThe slew speed (depth of cut) is already determined when selecting the bucket wheel.The accelerations (decelerations) should not exceed a = 0.1 m/s as otherwise a special stress analysis verification will be required.The travelling speed is usually limited to 30 m/min and the hoisting/lowering speed is 8 m/min.F: Control of the bucket wheel reclaimerDiagram 1 shows the reclaiming capacity as a function of a constant slew speed.Diagram 1 Constant slew speedThe reclaiming capacity drops as the cutting depth is reduced during slewing. By increasing the cutting width the volume in the buckets can be compensated for. This is done by increasing the slew speed.With controlled slew speed, the diagram 2 is as follows:Diagram 2 Controlled slew speedIn order to achieve a constant volumetric flow, a belt scale can be used to measure the reclaiming amount. The belt scale can only be used in the boom conveyor. Due to it being positioned here, it will have an idle time of several seconds which is no longer permissible for the control system and is - on its own - thus unsuitable.We can measure the direct influence of decreasing or increasing material flow on the bucket wheel. The motor power absorbed is our standard size.The belt scale is, however, also necessary, but only corrects the nominal capacity as selected.G: Reclaiming SystemsWhen making the following considerations, one proceeds as a rule on the assumption that in the area of automatic control 100% nominal capacity is also ensured. Lower capacities are performed when there is a need to accelerate or decelerate. Travelling and lifting/lowering of the boom must be considered separately.1. Long Travel ReclaimingIn long travel operation, cutting is performed by travelling the whole reclaimer alongside the stockpile. The cutting depth is set after each travel movement by advancing the bucket wheel boom. Face operation is possible both with slewable reclaimers and with TRENCHER reclaimers.Let us assume here that the machine moves with an average speed of 20 m/min and travels over a distance of about 200 m in one direction, then acceleration and braking must be additionally taken into account.Picture 3 Long Travel ReclaimingDuring acceleration/braking the full nominal capacity is no longer achieved which means that we must add in each case half the acceleration times to the reclaiming time with full reclaiming quantity.At an average travelling speed of 20 m/min, the acceleration/declaration time is all of 3.3 seconds.If we add in each case half of these times to the face reclaiming time, we arrive at a degree of operational efficiency of 99.5%.If the travelling time is assumed at only 50 m equivalent to 2.5 minutes, the degree of efficiency is still 97.8%.In the light of this high degree of efficiency of the reclaimer, it is not necessary to make an electronic calculation of the exact conditions. The control circuit tolerance of +/- 5% also has to be taken into account.2. Slew ReclaimingIn slew operation, the pile is reclaimed in benches by slewing the boom. After completion of each individual slewing movement the machine is advanced for the new cutting depth.To illustrate this procedure we can observe the motion diagram - speed of the bucket wheel over slew angle - as an example for the middle bench.The slewing process begins on the side near the runway by the acceleration of slewing. The acceleration ends at the point of intersection at the speed curve of the increasing height of cut. From this point of intersection, the control begins.The control ends when the maximum slew speed has been reached or when deceleration commences.2.1 Block ReclaimingOn block reclaiming, the stockpile is reclaimed in benches over a specified length. (Picture 4) The graph shows the development of the movements. After positioning the bucket wheel at the uppermost block, automatic operation will commence.Picture 4 Block Reclaiming SystemThe travel advance is performed during the deceleration phase and does not occur as additional idle time.At the end of the pile the machine has to move back to the position of the next bench. Only the travelling time is taken into account. Lowering of the boom and slewing into the new starting position is overlapped by the travelling time.The working cycle ends when the bucket wheel has reached the end of the pile in the lowest bench.2.2 Pilgrim Step ReclaimingThe graph for pilgrim step reclaiming is in principle built up on block reclaiming.However, in order to be able to reclaim the pile completely, a number of the travel advances have to be defined. The number of travel advances should be an even number in order to ensure that return travel takes place in a safe area of the pile.Picture 5 Pilgrim Step ReclaimingSlewing and lowering the boom into the next reclaiming position can take place during return travel and does not have to be especially taken into account.After new positioning, reclaiming can be resumed at the lowest block height.The working cycle ends in this case also when the bucket wheel has reached the end of the stockpile in the lowest bench.H: Easy Calculation MethodThe relations shown are normally calculated by a PC. The result is, however, relatively easy to calculate without a computer.The control system is the basis as this ensures that 100% nominal capacity is always achieved where the control is effective.If we take the cross section of a bench height and the reclaiming length, we arrive at the total reclaiming volume.If we divide the reclaiming volume by the nominal capacity we arrive at the reclaiming time at 100% nominal capacity.If we add the idle times indicated above to the reclaiming time we arrive at the degree of efficiency of the reclaimer by dividing the 100% reclaiming time by the reclaiming time with idle times.The idle times are approximated as follows:1. Acceleration/deceleration on slewingOn the runway side accelerate on an average up to a slew speed of 25 m/min or decelerate from a speed of 25 m/min. For the estimation 1/3 of the time will be considered.At about 75 the bucket wheel achieves the maximum slew speed and thus leaves the control range.The maximum slew speed is on average 40 m/min. The slewing time resulting with this slew speed up to deceleration shall be taken into account to an extent of 2/3. Likewise, 2/3 of the deceleration time following this shall be added on.2. Travelling timesOne travel advance occurs per slew movement. This shall not be taken into consideration as it is overlapped by deceleration.At the end of the reclaiming path and in pilgrim step operation at the end of the specified steps, the bucket wheel must be positioned for the following height of cut. The full return travel time shall be taken into account as idle time.3. Lowering and slewing for positioning the bucket wheelLowering and slewing times for positioning the bucket wheel are overlapped by the travelling time and do not, therefore, have to be additionally taken into account.This method of calculation results in a maximum error of 2% against the computer calculation.4. Results (guide values)4.1 Long travel reclaimingSee above4.2 Block reclaimingTrapezoidal pile Triangular pile- uppermost benchabt. 70%abt. 50%- middle benchabt. 85%abt. 70%- lowest benchabt. 95%abt. 85%- on averageabt. 88%abt. 75%4.3 Pilgrim step reclaiming- on average abt. 80%I: Improvements of the average reclaiming rate1. Adapting the cutting depthThe maximum cutting depth is normally determined as the cutting depth possible in the lower bench.The initial angle is larger in the upper benches and thus the cutting depth is smaller.If one adjusts the cutting depth referred to the initial angle and thus the travel advance, this will result in less slew movements over the length of the pile and one is able to improve the degree of efficiency of the reclaimer by about 2%.2. Longer boomA longer boom automatically means a trapezoidal pile. However, even in the case of already calculated trapezoidal piles it is possible to achieve an improvement in the average reclaiming rate by extending the length of the boom, as the bucket wheel is longer in contact per slew movement.3. Higher cutting height in the upper blockThis measure will not bring about any improvement in the average reclaiming rate but it will increase the degree of efficiency in the upper bench.4. Limiting the maximum slew angleAt a slew angle of about 70 the maximum slew speed is reached. The cutting depth then only amounts to about 1/3 of the initial angle.If upon reaching the max
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