外文翻譯--斗輪取料機(jī)的性能【中英文文獻(xiàn)譯文】

外文翻譯--斗輪取料機(jī)的性能【中英文文獻(xiàn)譯文】,中英文文獻(xiàn)譯文,外文,翻譯,斗輪取料機(jī),性能,機(jī)能,中英文,文獻(xiàn),譯文 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 Australia's 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 reclaimer's 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 reclaimer's 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 reclaimer's 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 reclaimer's 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 Boom's 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 rod@northcom.net.au. Jim Carr Boom Logistics jcarr@boomlogistics.com.au www.boomlogistics.com.au 全文： ? 2008年Reed商業(yè)信息有限公司保留所有權(quán)利。 Jamie Wade 在蒂森克虜伯公司中負(fù)責(zé)起重解決方案的工程師們的幫助下，減少了建立大型斗輪取料機(jī)的裝配時(shí)間，Rod Lind blade寫道。 增加澳大利亞煤炭運(yùn)輸港口吞吐能力的任務(wù)迫在眉睫——船舶長(zhǎng)時(shí)間等待裝載貨物的狀況對(duì)大多數(shù)人是無法接受的，這事與澳大利亞人做任何事都很準(zhǔn)時(shí)的原則相違背。 然而，一個(gè)有趣例子最近出現(xiàn)在馬偕中央昆士蘭海岸以南30公里處的干草點(diǎn)煤碼頭，這個(gè)例子反映了澳大利亞人的聰明才智和做事按時(shí)的原則。 “這是一個(gè)關(guān)于減少斗輪取料機(jī)裝配時(shí)間的程序，并且能節(jié)省重要的時(shí)間和金錢”，在與澳大利亞礦業(yè)部門初步討論這個(gè)項(xiàng)目時(shí)，負(fù)責(zé)業(yè)務(wù)發(fā)展和客戶解決方案經(jīng)理Jim Carr說。 蒂森克虜伯公司設(shè)計(jì)和建造了新的取料機(jī)，并且該公司的工程師們相信可以找到更快更好的方法來建立主臂，然后把所有組件都裝在主臂上，最后再把主臂安裝在已制造完成的堆取料機(jī)上。 蒂森克虜伯公司制訂了組裝新機(jī)器的新方式，然后工程師們?cè)谖锪髦匦瓦\(yùn)輸公司做試驗(yàn)，驗(yàn)證他們的想法是否能付諸實(shí)際運(yùn)行，并測(cè)試主臂是否需要一個(gè)獨(dú)特的設(shè)備來支持程序的運(yùn)行。 “以前在進(jìn)行此類工程時(shí)，從主臂的基礎(chǔ)部分依附到主機(jī)器還需要60米長(zhǎng)的臂來進(jìn)行逐步組裝”，蒂森克虜伯的Peter Chapman解釋道。 蒂森克虜伯工程師們?cè)O(shè)想的方法是在地面建造取料機(jī)的主臂，并在差不多完成的時(shí)候把主臂移近機(jī)器，然后把它舉至能依附在回轉(zhuǎn)甲板的位置。 “我們選擇與負(fù)責(zé)物流的重型運(yùn)輸專家討論這個(gè)工程”，Chapman說道。 “他們能夠判斷擬議的進(jìn)程是否可行，重要的是他們有設(shè)備去做這項(xiàng)工作”，Chapman說道。 “這是一個(gè)推、拉、執(zhí)行和解除的過程”，麥凱車廠物流重型運(yùn)輸司的Darren Jones說道。 “205噸重的取料機(jī)主臂安裝在離地只有2.4米高的基座上。 然后，我們能夠把125噸重的主臂舉起并搬動(dòng)“，Darren解釋道。 當(dāng)取料機(jī)主臂的一端被200的噸林格馬尼托瓦克起重機(jī)舉起的時(shí)候，所有運(yùn)作都已準(zhǔn)備好。 首先，主臂一端被林格起重機(jī)舉升到12米高度，這是在移動(dòng)進(jìn)程開始之前，為了使主臂能依附到回轉(zhuǎn)甲板所選的最終位置。 吊車暫停在自由轉(zhuǎn)換模式，所以主臂可移至主機(jī)器。 在林格起重機(jī)舉著取料機(jī)主臂時(shí)，回轉(zhuǎn)主臂——計(jì)算機(jī)輔助控制——我們能使主臂向前推動(dòng)1米。 然后，當(dāng)我們接近機(jī)器時(shí)，要小心控制，取料機(jī)的主臂微升到安裝點(diǎn)的位置。絕對(duì)精度要求能使重達(dá)180公斤的插腳插入主臂的軸承，Darren說道。 在這一過程中，利用重型運(yùn)輸設(shè)備和操縱人員，蒂森克虜伯公司能得到相當(dāng)大的節(jié)省，更重要的是，相比先前的技術(shù)裝備，降低了高空作業(yè)的危險(xiǎn)性 。 一是只需要一臺(tái)大型起重機(jī)，以替代兩個(gè)。 二是消除了許多高空工作問題。 三是縮短了工作完成的時(shí)間——約6個(gè)星期。 這就解釋了為什么能夠減少在海伊停泊點(diǎn)上進(jìn)行煤炭裝載所需的時(shí)間。 澳大利亞人是“無所不能”的人民，并在實(shí)際工程中屢見不鮮。只要放手讓它們做。 Jim Carr Boom Logistics BUCKET WHEEL RECLAIMERS AUTHOR: MR. W KNAPPE MAN TAKRAF Frdertechnik GmbH Performance of Bucket Wheel Reclaimers (Method of Calculation in Principle) A: Introduction The 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 Reclaimer The 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 Wheel 1. General The 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 Capacity The 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 Capacity The 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 Capacity The 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 Reclaimer The 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 influences Shape and size of the stockpile Number of benches to be reclaimed Prepared shape of stockpile for initial cut and end Travel, slew and hoist speeds of the reclaimer Accelerations of the movements Reclaiming method Indirect influences Maximum reclaiming amount must be restricted for other reasons Interruptions in operation Starting and braking of the conveyor system Weather influences Enclosed particles in the material which have to be removed by manually Caving in of stockpiles Intolerable stockpile construction deviations From 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 heights Bucket wheel reclaimers are familiar at triangular piles, trapezoidal piles and at trapezoidal piles with side banks. (Picture 2) Picture 2 Stockpile Shapes The 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 accelerations The 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 reclaimer Diagram 1 shows the reclaiming capacity as a function of a constant slew speed. Diagram 1 Constant slew speed The 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 speed In 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 Systems When 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 Reclaiming In 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 Reclaiming During 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 Reclaiming In 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 Reclaiming On 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 System The 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 Reclaiming The 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 Reclaiming Slewing 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 Method The 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 slewing On 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 times One 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 wheel Lowering 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 reclaiming See above 4.2 Block reclaiming Trapezoidal pile Triangular pile - uppermost bench abt. 70% abt. 50% - middle bench abt. 85% abt. 70% - lowest bench abt. 95% abt. 85% - on average abt. 88% abt. 75% 4.3 Pilgrim step reclaiming - on average abt. 80% I: Improvements of the "average reclaiming rate" 1. Adapting the cutting depth The 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 boom A 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 block This 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 angle At 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