齒輥破碎機(jī)的設(shè)計(jì)【新型的輥顎破碎機(jī)】
齒輥破碎機(jī)的設(shè)計(jì)【新型的輥顎破碎機(jī)】,新型的輥顎破碎機(jī),齒輥破碎機(jī)的設(shè)計(jì)【新型的輥顎破碎機(jī)】,破碎,設(shè)計(jì),新型
畢業(yè)設(shè)計(jì)（論文）任務(wù)書
I、畢業(yè)設(shè)計(jì)(論文)題目：
齒輥破碎機(jī)
II、畢 業(yè)設(shè)計(jì)(論文)使用的原始資料(數(shù)據(jù))及設(shè)計(jì)技術(shù)要求：
1、齒輥破碎機(jī)的結(jié)構(gòu)分析與設(shè)計(jì)結(jié)構(gòu)合理
2、齒輥破碎機(jī)齒輥工作面有一定耐磨性及其整體強(qiáng)度要求
3、要保證被破碎的物料粒度均勻及過粉率低
III、畢 業(yè)設(shè)計(jì)(論文)工作內(nèi)容及完成時(shí)間：
1、通過圖書館、上網(wǎng)查找大量書籍及相關(guān)資料 2周
2、齒輥破碎機(jī)的電機(jī)選擇及傳動(dòng)機(jī)構(gòu)設(shè)計(jì) 3周
3、帶傳動(dòng)、齒輪傳動(dòng)的計(jì)算 3周
4、齒輥參數(shù)計(jì)算 3周
5、鍵的選擇及其校核 2周
6、畢業(yè)論文整理及答辯準(zhǔn)備 2周
Ⅳ 、主 要參考資料：
1 .陳灝. 機(jī)械設(shè)計(jì)手冊(cè)，第2版.機(jī)械工業(yè)出版社，2000
2 .唐大放，馮曉寧，楊現(xiàn)卿.機(jī)械設(shè)計(jì)工程學(xué).徐州：中國(guó)礦業(yè)大學(xué)出版社,2001
3 .胡宗武，徐履冰，石來(lái)德.非標(biāo)準(zhǔn)機(jī)械設(shè)備設(shè)計(jì)手冊(cè)，2002
4 .甘永立.幾何量公差與檢測(cè).上海：上海科學(xué)技術(shù)出版社，2001
5. 單輝祖.材料力學(xué).北京：高等教育出版社，1999
航空工程 系 機(jī)械設(shè)計(jì)制造及自動(dòng)化 專業(yè)類 0881054 班
學(xué)生（簽名）：
填寫日期： 2012 年 2 月 20 日
指導(dǎo)教師（簽名）：
助理指導(dǎo)教師(并指出所負(fù)責(zé)的部分)：
系主任（簽名）：
附注:任務(wù)書應(yīng)該附在已完成的畢業(yè)設(shè)計(jì)說(shuō)明書首頁(yè)。
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本人聲明，所呈交的論文是本人在導(dǎo)師的指導(dǎo)下獨(dú)立完成的研究成果。除了文中特別加以標(biāo)注引用的內(nèi)容外，本論文不包含法律意義上已屬于他人的任何形式的研究成果,也不包含本人已用于其他學(xué)位申請(qǐng)的論文或成果。對(duì)本文的研究作出重要貢獻(xiàn)的個(gè)人和集體，均已在文中以明確方式表明。本人完全意識(shí)到本聲明的法律后果由本人承擔(dān)。
作者簽名： 日期：
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本學(xué)位論文作者完全了解學(xué)校有關(guān)保留、使用學(xué)位論文的規(guī)定，同意學(xué)校保留并向國(guó)家有關(guān)部門或機(jī)構(gòu)送交論文的復(fù)印件和電子版，允許論文被查閱和借閱。本人授權(quán)南昌航空大學(xué)科技學(xué)院可以將本論文的全部或部分內(nèi)容編入有關(guān)數(shù)據(jù)庫(kù)進(jìn)行檢索，可以采用影印、縮印或掃描等復(fù)制手段保存和匯編本學(xué)位論文。
作者簽名： 日期：
導(dǎo)師簽名： 日期：
畢業(yè)設(shè)計(jì)（論文）
題目： 齒輥破碎機(jī)
系 別 航空與機(jī)械工程系
專業(yè)名稱 機(jī)械設(shè)計(jì)制造及其自動(dòng)化
班級(jí)學(xué)號(hào) 088105439
學(xué)生姓名 朱芊全
指導(dǎo)教師 封立耀
二OO 年 月
畢業(yè)設(shè)計(jì)（論文）開題報(bào)告
題目 齒輥破碎機(jī)
專 業(yè) 名 稱 機(jī)械設(shè)計(jì)制造及自動(dòng)化
班 級(jí) 學(xué) 號(hào) 088105439
學(xué) 生 姓 名 朱芊全
指 導(dǎo) 教 師 封立耀
填 表 日 期 年 月 日
一、選題的依據(jù)及意義：
隨著國(guó)家經(jīng)濟(jì)建設(shè)的快速發(fā)展,將對(duì)礦藏資源需求量更高、更好，國(guó)家有限的資源量將無(wú)法滿足更多的需求，雙齒輥式破碎機(jī)不僅要具有高效性、環(huán)保性，更要具有復(fù)合性。通常使用的破碎機(jī)在工作時(shí)只能粗略的對(duì)礦石進(jìn)行破碎，很多還需要二次破碎，仍無(wú)法滿足生產(chǎn)生活需要，為此就不得不改變物料的破碎方式，物料的破碎效率，物料破碎的安全性環(huán)保性等多方面問題，為解決此問題在老師的指導(dǎo)下我設(shè)計(jì)這臺(tái)雙齒輥式破碎機(jī)，它可以有效的解決上述問題。我相信這臺(tái)破碎機(jī)能有效的節(jié)省和利用資源，對(duì)于提高生產(chǎn)、率環(huán)境保護(hù)和降低成本將會(huì)起到?jīng)Q定性作用，它一定會(huì)有很廣闊的市場(chǎng)前景!
二、國(guó)內(nèi)外研究概況及發(fā)展趨勢(shì)（含文獻(xiàn)綜述）：
輥式破碎機(jī)出現(xiàn)于1806年，它是一種較為古老的破碎設(shè)備。但是，由于它的結(jié)構(gòu)簡(jiǎn)單、緊湊輕便、易于制造、工作可靠，特別是它的產(chǎn)品過粉碎少，因此，至今仍在選煤、冶金燒結(jié)、水泥、玻璃、陶瓷等工業(yè)部門，以及小型選礦廠中使用，而且有新的改進(jìn)與發(fā)展。輥式破碎機(jī)被廣泛用于破碎軟質(zhì)和中等硬度的物料，對(duì)破碎濕料和黏性物料和堅(jiān)硬物料，使用范圍受到了限制。
近年來(lái)，國(guó)外輥式破碎機(jī)發(fā)展的得很快，種類也很齊全。按輥?zhàn)拥臄?shù)目，輥式破碎幾可以分為單輥、雙輥、三輥、和四輥四種；按輥面形狀，可以分為光輥、齒輥、槽輥破碎機(jī)，輥式破碎機(jī)等等
就其結(jié)構(gòu)而言，大多采用自動(dòng)移動(dòng)輥機(jī)結(jié)構(gòu)，液壓調(diào)整，油—液控制系統(tǒng)等新技術(shù)、新結(jié)構(gòu)。但各制造廠所采用的結(jié)構(gòu)形式和控制系統(tǒng)各有不同，獨(dú)具特色。如美國(guó)Pettibone公司生產(chǎn)的雙輥破碎機(jī)，應(yīng)用橡膠輪胎傳動(dòng)，液壓調(diào)整機(jī)構(gòu)，采用自動(dòng)定位滾子軸承，運(yùn)轉(zhuǎn)平穩(wěn)，使用壽命較長(zhǎng)。還有美國(guó)Portec公司生產(chǎn)的三輥破碎機(jī)，由一個(gè)固定輥和兩個(gè)移動(dòng)輥組成。移動(dòng)輥由彈簧保持壓力及固定工作位置。固定輥由齒輪驅(qū)動(dòng)，移動(dòng)輥由橡膠輪胎傳動(dòng)，可進(jìn)行單向給料破碎和雙向給料破碎。三輥破碎機(jī)由單輥破碎機(jī)和雙輥破碎機(jī)組合而成。而四輥破碎機(jī)由兩個(gè)雙輥破碎機(jī)組合而成，這種破碎機(jī)能完成粗碎和終碎兩道工序，破碎效率很高。輥式破碎機(jī)的規(guī)格用輥?zhàn)又睆紻和長(zhǎng)度L表示，例如輥?zhàn)又睆綖?200mm，輥?zhàn)娱L(zhǎng)度為為1000mm的輥式破碎機(jī)表示為：Φ1200mm×1000mm輥式破碎機(jī)。
3、 研究?jī)?nèi)容及實(shí)驗(yàn)方案：
設(shè)計(jì)目標(biāo)：
提高雙輥齒破碎機(jī)齒輥耐磨性和整體強(qiáng)度，使得齒輥在整個(gè)破碎工作過程中，不會(huì)因雙齒輥破碎機(jī)輥齒的長(zhǎng)時(shí)間工作和物料粒度過大而發(fā)生變形，降低事故率，提高破碎效率，保證生產(chǎn)的正常進(jìn)行，提高勞動(dòng)生產(chǎn)率。
研究?jī)?nèi)容：
（1）結(jié)構(gòu)分析設(shè)計(jì)；
（2）分析雙齒輥破碎機(jī)齒輥工作面耐磨性及其整體強(qiáng)度；
（3）整體結(jié)構(gòu)優(yōu)化。
四、目標(biāo)、主要特色及工作進(jìn)度
1、通過圖書館、上網(wǎng)查找大量書籍及相關(guān)資料 2周
2、齒輥破碎機(jī)的電機(jī)選擇及傳動(dòng)機(jī)構(gòu)設(shè)計(jì) 3周
3、帶傳動(dòng)、齒輪傳動(dòng)的計(jì)算 3周
4、齒輥參數(shù)計(jì)算 3周
5、鍵的選擇及其校核 2周
6、畢業(yè)論文整理及答辯準(zhǔn)備 2周
5、 參考文獻(xiàn)
1 .陳灝. 機(jī)械設(shè)計(jì)手冊(cè)，第2版.機(jī)械工業(yè)出版社，2000
2 .唐大放，馮曉寧，楊現(xiàn)卿.機(jī)械設(shè)計(jì)工程學(xué).徐州：中國(guó)礦業(yè)大學(xué)出版社,2001
3 .胡宗武，徐履冰，石來(lái)德.非標(biāo)準(zhǔn)機(jī)械設(shè)備設(shè)計(jì)手冊(cè)，2002
4 .甘永立.幾何量公差與檢測(cè).上海：上?？茖W(xué)技術(shù)出版社，2001
5. 單輝祖.材料力學(xué).北京：高等教育出版社，1999
6 .付峻青等.MMD625分級(jí)破碎機(jī)的應(yīng)用研究.煤炭科學(xué)技術(shù)，2001
8 .煤科院唐山分院.齒形結(jié)構(gòu)及齒的布置形式研究報(bào)告，1998
9 .錢振倫.移動(dòng)式和半移動(dòng)式破碎機(jī)的發(fā)展方向.礦山機(jī)械，1993
10.許居午等.新型輥式破碎機(jī)軸承座的有限元計(jì)算.礦山機(jī)械，1993
11.周杰等.新型強(qiáng)力分級(jí)破碎機(jī)的設(shè)計(jì)研究.煤炭加工與綜合利用，1999
12.梁金剛.煤用齒輥式破碎機(jī)的現(xiàn)狀及新發(fā)展.選煤技術(shù)，2001
13.方昆凡.公差與配合技術(shù)手冊(cè).北京：北京出版社，1998
齒輥破碎機(jī)
學(xué)生姓名：朱芊全 班級(jí)：088105439
指導(dǎo)老師：封立耀
摘要：新型雙齒輥破碎機(jī)由于結(jié)構(gòu)緊湊，破碎物料機(jī)理合理，適應(yīng)性強(qiáng)等突出的優(yōu)點(diǎn)，在露天礦物料粗碎應(yīng)用中很有發(fā)展前途，是較為理想的露天礦巖石破碎機(jī)。
本設(shè)計(jì)所涉及的新型的輥顎破碎機(jī)結(jié)合了顎式破碎機(jī)和齒輥破碎機(jī)的優(yōu)點(diǎn)，使生產(chǎn)能力得到了很大的提高，出料粒度的均一性得到了很好的保證，使物料得到了有效的破碎，這是有生產(chǎn)的實(shí)踐為證的。本文首先對(duì)新型雙齒輥破碎機(jī)進(jìn)行了電機(jī)的選擇、傳動(dòng)機(jī)構(gòu)的設(shè)計(jì);然后對(duì)齒輥的參數(shù)進(jìn)行計(jì)算，包括：輸入軸、偏心軸、小齒輥軸的結(jié)構(gòu)設(shè)計(jì)及校核等；最后進(jìn)行鍵的選擇及校核，包括：電機(jī)軸上、輸入軸上、偏心軸上、小齒輥軸上的鍵。
關(guān)鍵詞：新型雙齒輥破碎機(jī) 顎式破碎機(jī) 結(jié)構(gòu)設(shè)計(jì)
指導(dǎo)老師簽名：
Teeth roll crusher
Student name： Zhu Qianquan Class: 088105439
Supervisior: Feng Liyao
Abstract: Mineral sizer because the structure is compact, broken material mechanism is reasonable, strong adaptability of such prominent advantages, the original material crushing application promising, is the ideal open-pit mine rock crusher.
The design of the new type of roller involved jaw crusher combines jaw crusher and the advantages of the teeth roll crusher, make the production capacity were greatly increased, the grain-size homogeneity of got a very good guarantee, make the material effectively of broken, it is the practice of production for the card. This paper first to mineral sizer the choice of the motor, a transmission mechanism design; And then the teeth roll the parameters of the computation, including: input shaft, eccentric shaft, small teeth of the roller structure design and check; The last key selection and checking, including: motor shaft, input shaft, eccentric shaft on small teeth, the key on the roller.
keywords: mineral sizer jaw crusher structure design
Signature of Supervisior:
外文資料翻譯
題目： 齒輥破碎機(jī)
系 別 航空與機(jī)械工程系
專業(yè)名稱 機(jī)械設(shè)計(jì)制造及自動(dòng)化
班級(jí)學(xué)號(hào) 088105439
學(xué)生姓名 朱芊全
指導(dǎo)教師 封立耀
二O一二 年 三 月
第 18 頁(yè)
翻譯
英文原文
COMMINUTION IN A NON-CYLINDRICAL ROLL CRUSHER*
P. VELLETRI ~ and D.M. WEEDON ~
~[ Dept. of Mechanical & Materials Engineering, University of Western Australia, 35 Stirling Hwv,
Crawley 6009, Australia. E-mail piero@mech.uwa.edu.au
§ Faculty of Engineering and Physical Systems, Central Queensland University, PO Box 1!:;19,
Gladstone, Qld. 4680, Australia
(Received 3 May 2001; accepted 4 September 2001)
ABSTRACT
Low reduction ratios and high wear rates are the two characteristics ntost commonh" associated with conventional roll crushers. Because of this, roll crushers are not often considered Jor use in mineral processing circuits, attd many of their advantages are being largely overlooked. This paper describes a novel roll crusher that has been developed ipt order to address these issues.Relbrred to as the NCRC (Non-Cylindrical Roll Crusher), the new crusher incorporates two rolls comprised qf an alternating arrangement of platte attd convex or concave su@wes. These unique roll prqfiles improve the angle qf nip, enabling the NCRC to achieve higher reduction ratios than conventional roll crushers. Tests with a model prototype have indicated thar evell fi)r very hard ores, reduction ratios exceeding lO:l can be attained. In addition, since the comminution process in the NCRC combines the actions of roll arM jaw crushers there is a possibili 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 lcd 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 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 feeci ~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 dcveloped at the University of Western Australia in ordcr 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 surfaccs. Thcse 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 oics,
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 bv examining inulti-particle comminution inthe NCRC. It also looks at various othcr factors that influencc the perli~rmance 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 effccting the performance of a roll crusher. Smaller nip angles
are beneficial since they increase tl~e likelihood of parlictes bcing grabbed and crushed by lhe rolls. For a
given feed size and roll gap, the nip angle in a conventional rtHl crusher is limited by the size of thc 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 commmution were considered when selecting
Ille roll profiles. The final shapes of the NCRC rolls are shown in Figure I. One of the rolls consists {sI an
alternating arrangement of plane and convex surfaces, while the other is formed from an alternating
arrangement of phme and concave surlaccs.
The shape of the rolls on the NCRC result in several unique characteristics. Tile most important is that, lk)r
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 highcr. 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, thc
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, tidls below 25 ° once as the rolls rotate by (~0 degrees. This means that the non-cylindrical
rolls have a possibility of nipping the particlc 6 times during one roll rewHution.
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
componcnt 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.
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 zonc during operation and also allows the crushing sequence to
bc 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 Mining's Golden Grove operations, while the mill scats were obtained from
Aurora Gold's Mt Muro mine site in central Kalimantan. The mill scats 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).
RESULTS
Feed material
The performance of all comminution equipment is dependent on the type of material being crushed. In this
respect, the NCRC is no different. Softer materials crushed in the NCRC yield a lower P80 than harder
materials. Figure 4 shows the product size distribution obtained when several different materials were
crushed under similar conditions in the NCRC. It is interesting to note that apart from the prepared concrete
samples, the P80 values obtained from the various materials were fairly consistent. These results reflect the
degree of control over product size distribution that can be obtained with the NCRC.
Multiple feed particles
Previous trials with the NCRC were conducted using only single feed particles where there was little or no
interaction between particles. Although very effective, the low throughput rates associated with this mode
of comminution makes it unsuitable for practical applications. Therefore it was necessary to determine the
effect that a continuous feed would have to the resulting product size distribution. In these tests, the NCRC
was continuously supplied with feed to maintain a bed of material level with the top of the rolls. Figure 5
shows the effect that continuous feed to the NCRC had on the product size distribution for the Normandy
Ore. These results seem to show a slight increase in P80 with continuous (multi-particle) feed, however the
shift is so small as to make it statistically insignificant. Similarly, the product size distributions would seem
to indicate a larger proportion of fines for the continuously fed trial, but the actual difference is negligible.
Similar trials were also conducted with the granite samples using two different roll gaps, as shown in
Figure 6. Once again there was little variation between the single and multi-particle tests. Not surprisingly,
the difference was even less significant at the larger roll gap, where the degree of comminution (and hence
interaction between particles) is smaller.
All of these tests would seem to indicate that continuous feeding has minimal effect on the performance of
the NCRC. However, it is important to realise that the feed particles used in these trials were spread over a
very small size range, as evident by the feed size distribution shown in Figure 6 (the feed particles in the
Normandy trials were even more uniform). The unilormity in feed particle size results in a large amount of
free space, which allow:s for swelling of the broken ore in the crushing chamber, thereby limiting the
amount of interaction between particles. True "choke" feeding of the NCRC with ore having a wide
distribution of particle sizes (especially in the smaller size range) is likely to generate much larger pressures
in the crushing zone. Since the NCRC is not designed to act as a "'high pressure grinding roll" a larger
number of oversize particles would pass between the rolls under these circumstances.
Roll gap
As with a traditional roll crusher, the roll gap setting on the NCRC has a direct influence on the product
size distribution and throughput of the crusher. Figure 7 shows the resulting product size distribution
obtained when the Aurora Gold ore (mill scats) was crushed at three different roll gaps. Plotting the PSO
values taken from this graph against the roll gap yields the linear relationship shown in Figure 8. As
explained previously, the actual roll gap on the NCRC will vary over one revolution. This variation
accounts for the difference between the specified gap setting and product Ps0 obtained from the crushing
trials. Figure 8 also shows the effect of roll gap on throughput of the crusher and gives an indication of the
crushing rates that can be obtained with the laboratory scale model NCRC.
Roll force
The NCRC is designed to operate with minimal interaction between particles, such that comminution is
primarily achieved by fracture of particles directly between the rolls. As a consequence, the roll force only
needs to bc large enough to overcome the combined compressive strengths of the particles between the roll
surlaces. If the roll force is not large enough then the ore particles will separate the rolls allowing oversized
particles to lall through. Increasing the roll force reduces the tendency of the rolls to separate and therefore
provides better control over product size. However, once a limiting roll force has been reached (which is
dependent on the size and type of material being crushed) any further increase in roll force adds nothing to
the performance of the roll crusher. This is demonstrated in Figure 9, which shows that for granite feed of
25-3 Imm size, a roll force of approximately 16 to 18 kN is required to control the product size. Using a
larger roll force has little effect on the product size, although there is a rapid increase in product P80 if the
roll force is reduced bek>w this level.
As mentioned previously, the feed size distribution has a significant effect on the pressure generated in the
crushing chamber. Ore that has a finer feed size distribution tends to "choke" the NCRC more, reducing the
effectiveness of the crusher. However, as long as the pressure generated in not excessive the NCRC
maintains a relatively constant operating gap irrespective of the feed size. The product size distribution
will, therefore, also bc independent of the feed size distribution. This is illustrated in Figure 10, which
shows the results of two crushing trials using identical equipment settings but with feed ore having
different size distributions. In this example, the NCRC reduced the courser ore from an Fs0 of 34mm to a
Ps0 of 3.0mm (reduction ratio of 11:1), while the finer ore was reduced from an Fs0 of 18mm to a Pso of
3.4mm (reduction ratio of 5:1). These results suggest that the advantages of using profiled rolls diminish as
the ratio of the feed size to roll size is reduced. In other words, to achieve higher reduction ratios the feed
particles must be large enough to take advantage of the improved nip angles generated in the NCRC.
Mill scats
Some grinding circuits employ a recycle or pebble crusher (such as a cone crusher) to process material
which builds up in a mill and which the mill finds hard to break (mill scats). The mill scats often contain
worn or broken grinding media, which can find its way into the recycle crusher. A tolerance to uncrushable
material is therefore a desirable characteristic for a pebble crusher to have. The NCRC seems ideally suited
to such an application, since one of the rolls has the ability to yield allowing the uncrushable material to
pass through.
The product size distributions shown in Figure 1 1 were obtained from the processing of mill scats in the
NCRC. Identical equipment settings and feed size distributions were used for both results, however one of
the trials was conducted using feed ore in which the grinding media had been removed. As expected, the
NCRC was able to process the feed ore containing grinding media without incident. However, since one
roll was often moving in order to allow the grinding media to pass, a number of oversized particles were
able to fall through the gap without being broken. Consequently, the product size distribution for this feed
ore shows a shift towards the larger particle sizes, and the Ps0 value increases from 4ram to 4.7mm. In spite
of this, the NCRC was still able to achieve a reduction ratio of almost 4:1.
Wear
Although no specific tesls were conducted to determine the wear rates on the rolls of the NCRC, a number
of the crushing trials were recorded using a high-speed video camera in order to try and understand the
comminution mechanism. By observing particles being broken between the rolls it is possible to identify
portions of the rolls which are likely to suffer from high wear and to make some subjective conclusions as
to the effect that this wear will have on the perlbrmance of the NCRC. Not surprisingly, the region that
shows up as being the prime candidate for high wcar is the transition between the flat and concave surfaces.
What is surprising is that this edge does not play a significant role in generating the improved nip angles.
The performance of the NCRC should not be adversely effccted by wear to this edge because it is actually
the transition between the fiat and convex surfaces (on the opposing roll) that results in the reduced nip
angles.
The vide() also shows that tor part of each cycle particles are comminuted between the flat surfaces of the
rolls, in much the same way as they would be in a jaw crusher. This can be clearly seen on the sequence of
images in Figure 12. The wear on the rolls during this part of the cycle is likely' to be minimal since there is
little or no relative motion between the particles and the surface of the rolls.
CONCLUSIONS
The results presented have demonstrated some of the factors effecting the comminution of particles in a
non-cylindrical roll crusher. The high reduction ratios obtained from early single particle tests can still be
achieved with continuous multi-particle feed. However, as with a traditional roll crusher, the NCRC is
susceptible to choke feeding and must be starvation fed in order to operate effectively. The type of feed
material has little effect on the performance of the NCRC and, although not tested, it is anticipated that the
moisture content of the feed ore will also not adversely affect the crusher's per[Brmance. Results from the
mill scat trials are particularly promising because they demonstrate that the NCRC is able to process ore
containing metal from worn grinding media. The above factors, in combination with the flaky nature of the
product generated, indicate that the NCRC would make an excellent recycle or pebble crusher. It would
also be interesting to determine whether there is any difference in the ball mill energy required to grind
product obtained from the NCRC compared that obtained from a cone crusher.
中文譯文
摘要
低的破碎比和高的磨損率是與傳統(tǒng)的破碎機(jī)相聯(lián)系的很常見的兩個(gè)特性。因?yàn)檫@點(diǎn)，在礦石處理流程的應(yīng)用中，很少考慮到它們，并且忽略了很多它們的優(yōu)點(diǎn)。本文描述了一個(gè)已被發(fā)展起來(lái)的新穎的對(duì)輥破碎機(jī)，旨在提出這些論點(diǎn)。作為NCRC,這種新式破碎機(jī)結(jié)合了兩個(gè)輥筒，它們由一個(gè)交替布置的平面和一個(gè)凸的或者凹的表面組成。這種獨(dú)特的輥筒外形提高了嚙合角，使NCRC可以達(dá)到比傳統(tǒng)輥式破碎機(jī)更高的破碎比。用一個(gè)模型樣機(jī)做的試驗(yàn)表明：即使對(duì)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(jié)合了輥式和顎式破碎機(jī)的作用，那就有一種可能：那種新的輪廓會(huì)帶來(lái)輥?zhàn)幽p率的降低。
關(guān)鍵字：
介紹
傳統(tǒng)的輥筒破碎機(jī)因?yàn)榫哂袔讉€(gè)缺陷而導(dǎo)致了其在礦石處理應(yīng)用中的不受歡迎。尤其是當(dāng)與其它的一些破碎機(jī)比起來(lái)，諸如圓錐破碎機(jī)等，它們的低破碎比（一般局限在3以內(nèi)）和高的磨損率使它們沒
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