（ 二 一 三 年 六 月 本科畢業(yè)設計 外文文獻翻譯 學生姓名 ： 學 院 ： 機械學院 系 別： 機械系 專 業(yè)： 機 械 電 子 工 程 班 級： 機電 09 指導教師 ： 講師 學校代碼： 10128 學 號： 內蒙古工業(yè)大學本科畢業(yè)設計說明書 原文： COMMINUTION IN A NON-CYLINDRICAL ROLL CRUSHER* P. VELLETRI and D.M. WEEDON Dept. of Mechanical & Materials Engineering, University of Western Australia, 35 Stirling Hwy, Crawley 6009, Australia. E-mail .au Faculty of Engineering and Physical Systems, Central Queensland University, PO Box 1319 Gladstone, Qld. 4680, Australia (Received 3 May 2001; accepted 4 September 2001) Velletri and Weedon, 2000 P. Velletri and D.M. Weedon, Preliminary investigations into a roll crusher with non-cylindrical rolls, Proc. Minprex 2000 International Congress on Mineral Processing and Extractive Metallurgy, AIMM, Melbourne (2000), pp. 321328. ABSTRACT Low reduction ratios and high wear rates are the two characteristics most commonly associated with conventional roll crushers. Because of this, roll crushers are not often considered Jor use in mineral processing circuits, and many of their advantages are being largely overlooked. This paper describes a novel roll crusher that has been developed in order to address these issues.Referred to as the NCRC (Non-Cylindrical Roll Crusher), the new crusher incorporates two rolls comprised of an alternating arrangement of plane and convex or concave surfaces. These unique roll profiles improve the angle of nip, enabling the NCRC to achieve higher reduction ratios than conventional roll crushers. Tests with a model prototype have indicated thar even for very hard ores, reduction ratios exceeding l0:l can be attained. In addition, since the comminution process in the NCRC combines the actions of roll and jaw crushers there is a possibility O that the new profiles may lead to reduced roll wear rates. 2001 Elsevier Science Ltd. All rights reserved. Keywords: Comminution; crushing INTRODUCTION Conventional roll crushers suffer from several disadvantages that have led to their lack of popularity in mineral processing applications. In particular, their low reduction ratios (typically limited to about 3:1) and high wear rates make them unattractive when compared to other types of comminution equipment, such as cone crushers. There are, however, some characteristics of roll crushers that are very desirable from a mineral processing point of view. The relatively constant operating gap in a roll crusher gives good control over product size. The use of spring-loaded rolls 內蒙古工業(yè)大學本科畢業(yè)設計說明書 make these machines tolerant to uncrushable material (such as tramp metal). In addition, roll crushers work by drawing material into the compression region between the rolls and do not rely on gravitational feed like cone and jaw crushers. This generates a continuous crushing cycle, which yields high throughput rates and also makes the crusher capable of processing wet and sticky ore. The NCRC is a novel roll crusher that has been developed at the University of Western Australia in order to address some of the problems associated with conventional roll crushers. The new crusher incorporates two rolls comprised of an alternating arrangement of plane and convex or concave surfaces. These unique roll profiles improve the angle of nip, enabling the NCRC to achieve higher reduction ratios than conventional roll crushers. Preliminary tests with a model prototype have indicated that, even for very hard ores,reduction ratios exceeding 10:I can be attained (Vellelri and Weedon, 2000). These initial findings were obtained for single particle feed. where there is no significant interaction between particles during comminution. The current work extends the existing results by examining multi-particle comminution in the NCRC. It also looks at various other factors that influence the performance of the NCRC and explores the effectiveness of using the NCRC for the processing of mill scats. PRINCIPLE OF OPERATION The angle of nip is one of the main lectors effecting the performance of a roll crusher. Smaller nip angles are beneficial since they increase the likelihood of particles being grabbed and crushed by the rolls. For a given feed size and roll gap, the nip angle in a conventional roll crusher is limited by the size of the rolls. The NCRC attempts to overcome this limitation through the use of profiled rolls, which improve the angle of nip at various points during one cycle (or revolution) of the rolls. In addition to the nip angle, a number of other factors including variation m roll gap and mode of comminution were considered when selecting the roll profiles. The final shapes of the NCRC rolls are shown in Figure I. One of the rolls consists of an alternating arrangement of plane and convex surfaces, while the other is formed from an alternating arrangement of plane and concave surfaces. 內蒙古工業(yè)大學本科畢業(yè)設計說明書 The shape of the rolls on the NCRC result in several unique characteristics. The most important is that, for a given particle size and roll gap, the nip angle generated m the NCRC will not remain constant as the rolls rotate. There will be times when the nip angle is much lower than it would be for the same sized cylindrical rolls and times when it will be much higher. The actual variation in nip angle over a 60 degree roll rotation is illustrated in Figure 2, which also shows the nip angle generated under similar conditions m a cylindrical roll crusher of comparable size. These nip angles were calculated for a 25ram diameter circular particle between roll of approximately 200ram diameter set at a I mm minimum gap. This example can be used to illustrate the potential advantage of using non-cylindrical rolls. In order for a particle to be gripped, the angle of nip should normally not exceed 25 . Thus, the cylindrical roll crusher would never nip this particle, since the actual nip angle remains constant at approximately 52 . The nip angle generated by the NCRC, however, the below 25 once as the rolls rotate by (0 degrees. This means that the non-cylindrical rolls have a possibility of nipping the particle 6 times during one roll revolution. EXPERIMENTAL PROCEDURE The laboratory scale prototype of the NCRC (Figure 3) consists of two roll units, each comprising a motor, gearbox and profiled roll. Both units are mounted on linear bearings, which effectively support any vertical component of force while enabling horizontal motion. One roll unit is horizontally fixed while the other is restrained via a compression spring, which allows it to resist a varying degree of horizontal load. 內蒙古工業(yè)大學本科畢業(yè)設計說明書 The pre-load on the movable roll can be adjusted up to a maximum of 20kN. The two motors that drive the rolls are electronically synchronised through a variable speed controller, enabling the roll speed to be continuously varied up to 14 rpm (approximately 0.14 m/s surface speed). The rolls have a centre-to-centre distance ,at zero gap setting) of I88mm and a width of 100mm. Both drive shafts are instrumented with strain gauges to enable the roll torque to be measured. Additional sensors are provided to measure the horizontal force on the stationary roll and the gap between the rolls. Clear glass is fitted to the sides of the NCRC to facilitate viewing of the crushing zone during operation and also allows the crushing sequence to be recorded using a high-speed digital camera. Tests were performed on several types of rocks including granite, diorite, mineral ore, mill scats and concrete. The granite and diorite were obtained from separate commercial quarries; the former had been pre-crushed and sized, while the latter was as-blasted rock. The first of the ore samples was SAG mill feed obtained from Normandy Minings Golden Grove operations, while the mill scats were obtained from Aurora Golds Mt Muro mine site in central Kalimantan. The mill scats 內蒙古工業(yè)大學本科畢業(yè)設計說明書 included metal particles of up to 18ram diameter from worn and broken grinding media. The concrete consisted of cylindrical samples (25mm diameter by 25ram high) that were prepared in the laboratory in accordance with the relevant Australian Standards. Unconfined uniaxial compression tests were performed on core samples (25mm diameter by 25mm high) taken from a number of the ores. The results indicated strength ranging from 60 MPa for the prepared concrete up to 260 MPa for the Golden Grove ore samples. All of the samples were initially passed through a 37.5mm sieve to remove any oversized particles. The undersized ore was then sampled and sieved to determine the feed size distribution. For each trial approximately 2500g of sample was crushed in the NCRC. This sample size was chosen on the basis of statistical tests, which indicated that at least 2000g of sample needed to be crushed in order to estimate the product P80 to within +0.1ram with 95% confidence. The product was collected and riffled into ten subsamples, and a standard wet/dry sieving method was then used to determine the product size distribution. For each trial, two of the sub-samples were initially sieved. Additional sub-samples were sieved if there were any significant differences in the resulting product size distributions. A number of comminution tests were conducted using the NCRC to determine the effects of various parameters including roll gap, roll force, feed size, and the effect of single and multi-particle feed. The roll speed was set at maximum and was not varied between trials as previous experiments had concluded that there was little effect of roll speed on product size distribution. It should be noted that the roll gap settings quoted refer to the minimum roll gap. Due to the non-cylindrical shape of the rolls, the actual roll gap will vary up to 1.7 mm above the minimum setting (ie: a roll gap selling of l mm actually means 1-2.7mm roll gap). 內蒙古工業(yè)大學本科畢業(yè)設計說明書 譯文： 在非圓柱輥式破碎機 中 粉碎 P. VELLETRI and D.M. WEEDON 機械與材料工程，西澳大利亞大學，斯特林 HWV35 部， 克勞利 6009，澳大利亞。電子郵箱 .au 工程學院和物理系統(tǒng)，中央昆士蘭大學，郵政信箱 1319 格萊斯頓， QLD。 4680，澳大利亞 （ 2001 年 5 月 3 日收稿， 2001 年 9 月 4 日接受） 韋萊特里和威登， 2000 年 P.韋萊特里和 D.M.威登，與非圓柱輥， PROC 的輥式破碎機進行初步調查。 Minprex2000 選礦和冶煉， AIMM，墨爾本國際大會（ 2000年），頁 321-328。 摘 要 低的破碎比和高的磨損率是與傳統(tǒng)的破碎機相聯(lián)系的很常見的兩個特性。因為這點，在礦石處理流程的應用中，很少考慮到它們，并且忽略了很多它們的優(yōu)點。本文描述了一個已被發(fā)展起來的新穎的對輥破碎機，旨在提出這些論點。作為 NCRC,這種新式破碎機結合了兩個輥筒，它們由一個交替布置的平面和一個凸的或者凹的表面組成。這種獨特的輥筒外形提高了嚙合角，使 NCRC 可以達到比傳統(tǒng)輥式破碎機更高的破碎比。用一個模型樣機做的試驗表明：即使對于非常硬的礦石，破碎比任可以超過 10。另外，既然在 NCRC 的破碎處理中結合了輥式和顎式破碎機的作用 ，那就有一種可能：那種新的輪廓會帶來輥子磨損率的降低。 關鍵字： 粉碎；破碎 介 紹 傳統(tǒng)的輥筒破碎機因為具有幾個缺陷而導致了其在礦石處理應用中的不受內蒙古工業(yè)大學本科畢業(yè)設計說明書 歡迎。尤其是當與其它的一些破碎機比起來，諸如圓錐破碎機等，它們的低破碎比（一般局限在 3 以內）和高的磨損率使它們沒有吸引力。然而，從礦石處理這一點來說，輥筒破碎機有一些非?？扇〉奶攸c：輥筒破碎機的相對穩(wěn)定的操作寬度可以很好控制產物粒度。彈簧承重的輥子的使用使這些機器容許不可破碎的物料（諸如夾雜金屬等）。另外，輥筒破碎機是這樣工作的：將物料牽引至輥子之間 的擠壓區(qū)而不是象圓錐和顎式破碎機那樣依靠重力。這產生了一個連續(xù)的破碎周期，避免了高通過率，同時也使破碎機可處理潮濕的和膠粘的物料。 NCRC 是一種新穎的破碎機，發(fā)明于澳大利亞西部大學，為得是提出一些與傳統(tǒng)輥筒破碎機相聯(lián)系的一些問題。新的破碎機結合了兩個輥子，由間隔布置的平面和凸的或者凹的表面組成。這種獨特的輥子輪廓提高了嚙合角，使 NCRC 可達到比傳統(tǒng)輥筒破碎機更高的破碎比。用一個模型樣機的初步試驗已表明：即使非常硬的物料，超過 10 的破碎比也可以實現(xiàn)。這些初期的發(fā)現(xiàn)是通過單一顆粒進給而獲得的，在破碎中沒有顯 著的物塊間的相互作用。目前的工作在 NCRC 中用多物塊試驗延伸了現(xiàn)存的結果。同時也顧及了各種其他因素：影響 NCRC 特性和探索 NCRC 在選礦處理中使用效率。 操作原理 嚙合角是影響輥筒破碎機性能的重要因素之一。小的嚙合角是有利的，因為它們增大了物塊被輥筒抓住的可能性。對于一個給定的入料粒度和輥隙，傳統(tǒng)的輥筒破碎機的嚙合角受限于輥筒的尺寸。 NCRC 試圖通過有特殊輪廓的輥筒克服這種限制，這種輪廓提高了輥筒在一轉中變化點的嚙合角。至于嚙合角，在選擇輥面時，很多其他的因素，包括變化的輥隙，破碎的方式都考慮了。最終 NCRC輥筒形狀如圖 1 所示。其中一個輥子由間隔布置的平面和凸面組成，而另一個是由間隔布置的平面和凹面組成。 NCRC 輥筒的形狀導致了幾個獨特的特點。其中最重要的就是在輥筒轉動時，對于一個給定物塊粒度和輥隙， NCRC 所產生的嚙合角將不再保持穩(wěn)定。時而嚙合角比相同尺寸的圓柱輥筒低很多，時而高很多。輥子轉動中嚙合角的實際變化量超過 60 度，如圖 2 所示，圖 2 也表示了相同情況下，可相比尺寸的圓柱輥筒破碎機所產生的嚙合角。這些嚙合角是對一個直徑為 25 毫米的圓形物塊放在輥徑大約 200 毫米、最小輥隙 1 毫米的輥筒間計算出來的。這 個例子可以用來描述內蒙古