Numerical Simulation and Optimization of the Gas-Solid Coupled Flow Field and Discharging Performance of Straw Crushers

The quality of crushing,power consumption,and discharging performance of a straw crusher are greatly influenced by the characteristics of its internalflowfield.To enhance the straw crusher’sflowfield properties and improve the efficiency with which crushed material is discharged,first,the main structural parameters influencing the airflow in the crusher are discussed.Then,the coupled gas-solidflowfield in the straw crusher is numerically calculated through solution of the Navier-Stokes equations and application of the discrete element method(DEM).Finally,the discharge performance index of the crusher is examined through detailed analysis of the crushed material dynamics.Additionally,a multi-island genetic algorithm is used to optimize the structure and operational factors that have significant effects on the discharge performance.With optimization,the accumulation rate of crushed materials in the bottom region of the straw crusher decreases by 20.08%,and the massflow rate at the discharge outlet increases by 11.63%.

Multi-object optimization design for differential and grading toothed roll crusher using a genetic algorithm

Our differential and grading toothed roll crusher blends the advantages of a toothed roll crusher and a jaw crusher and possesses characteristics of great crushing,high breaking efficiency,multi-sieving and has,for the moment,made up for the short- comings of the toothed roll crusher.The moving jaw of the crusher is a crank-rocker mechanism.For optimizing the dynamic per- formance and improving the cracking capability of the crusher,a mathematical model was established to optimize the transmission angleγand to minimize the travel characteristic value m of the moving jaw.Genetic algorithm is used to optimize the crusher crank-rocker mechanism for multi-object design and an optimum result is obtained.According to the implementation,it is shown that the performance of the crusher and the cracking capability of the moving jaw have been improved.

Influence of some rock strength properties on jaw crusher performance in granite quarry

The influence of rock strength properties on Jaw Crusher performance was carried out to determine the effect of rock strength on crushing time and grain size distribution of the rocks.Investigation was conducted on four different rock samples namely marble,dolomite,limestone and granite which were representatively selected from fragmented lumps in quarries.Unconfined compressive strength and Point load tests were carried out on each rock sample as well as crushing time and size analysis.The results of the strength parameters of each sample were correlated with the crushing time and the grain size distribution of the rock types.The results of the strength tests show that granite has the highest mean value of 101.67 MPa for Unconfined Compressive Strength(UCS) test,6.43 MPa for Point Load test while dolomite has the least mean value of 30.56 MPa for UCS test and 0.95 MPa for Point Load test.According to the International Society for Rock Mechanic(ISRM) standard,the granite rock sample may be classified as having very high strength and dolomite rock sample,low strength.Also,the granite rock has the highest crushing time(21.0 s) and dolomite rock has the least value(5.0 s).Based on the results of the investigation,it was found out that there is a great influence of strength properties on crushing time of rock types.

Application of analytical hierarchy process to selection of primary crusher

Selection of crusher required a great deal of design based on the mining plan and operation input. Selection of the best primary crusher from all of available primary crushers is a Multi-Criterion Decision Making （MCDM） problem, in this paper, the Analytical Hierarchy Process （AHP） method was used to selection of the best primary crusher for Golegohar Iron Mine in Iran. For this reason, gyratory, double toggle jaw, single toggle jaw, high speed roll crusher, low speed sizer, impactor, hammer mill and feeder breaker crushers were considered as alternatives and capacity, feed size, product size, rock compressive strength, abrasion index and mobility of crusher were considered as criteria. As a result of our study, the gyvratory crusher was offered as the best primary crusher for the studied mine.

Fuzzy TOPSIS method to primary crusher selection for Golegohar Iron Mine(Iran)

Selection of the crusher required a great deal of design regarding to the mine planning. Selection of suitable primary crusher from all of available primary crushers is a multi-criterion decision making(MCDM) problem. The present work explores the use of technique for order performance by similarity to ideal solution(TOPSIS) with fuzzy set theory to select best primary crusher for Golegohar Iron Mine in Iran. Gyratory, double toggle jaw, single toggle jaw, high speed roll crusher, low speed sizer, impact crusher, hammer mill and feeder breaker crushers have been considered as alternatives. Also, the capacity, feed size, product size, rock compressive strength, abrasion index and application of primary crusher for mobile plants were considered as criteria for solution of this MCDM problem. To determine the order of the alternatives, closeness coefficient is defined by calculating the distances to the fuzzy positive ideal solution(FPIS) and fuzzy negative ideal solution(FNIS). Results of our work based on fuzzy TOPSIS method show that the gyratory is the best primary crusher for the studied mine.

Material Flow in Jaw Crusher

Jaw crusher is a kind of machine widely used in mining and aggregates industry,but it still has some shortcom- ings,such as liners wear,terrible power draw etc.The lack of research on material flow strongly limits the design improvement. The size reduction of the jaw crusher relies on the moving jaw movement that is a kind of complicated swing.Based on the move- ment analysis of the moving jaw and the single particle breakage characters,the material flow is analyzed.The measure of the breakage force is carried out.Material flow analysis is partly confirmed by the experimental results and some new information is also learned from the crushing force distribution.The job on the material flow will be helpful to the jaw crusher design improve- ment.

.NET程序汉化一例——Cookie Crusher的汉化

前天,在CNET下载到Cookie Crusher这个软件,发现是.net编写的,按照习惯,先检测程序是否被加壳,结果不错,没加,接着用EXEScope打开主程序,发现资源项目下只有图标和版本这两个东东:

Research on Structural Design of Coal Crusher House in Thermal Power Plant

This paper takes the specific characteristics of pulverized coal room in thermal power plant as the starting point,firstly,this paper analyzes the process layout and structure selection,and then the structural design and vibration design requirements of coal crusher house are introduced in this paper.Finally,based on the engineering example,a new structure form of vibration isolation design is creatively proposed,which provides a new design idea for the practical engineering design.

破碎机自主作业轨迹规划研究

对破碎机工作装置工作过程中的运动轨迹进行规划,结合机器人机械臂的研究理论,基于改进型D-H法建立了破碎机工作装置模型;建立工作装置运动学模型,对其进行正向运动学分析,并通过运动学逆解得到回转平台、动臂、斗杆在空间中不同位置下的关节角度;在关节空间内分别使用5次多项式曲线、7次多项式曲线与9次多项式曲线规划了工作装置的运动轨迹。在Matlab平台内通过Robotics Toolbox搭建工作装置D-H参数模型并对3种方法进行仿真,获得了关节回转的角度、角速度和角加速度变化曲线并进行对比分析,发现7次多项式规划的角加速度曲线平滑连续、没有突变且波动较小,能够保证工作装置运动的连续性与平稳性。

含轴承间隙复摆颚式破碎机动态性能分析

在复摆颚式破碎机中,轴承间隙对其稳定性及轴承寿命均有一定影响。为分析轴承间隙对复摆颚式破碎机动态性能的影响,采用拉格朗日乘子法,建立含轴承间隙复摆颚式破碎机的动力学模型,分析了不同偏心轴转速及间隙值对破碎机动态性能的影响;并通过试验验证了其准确性。结果表明,增加偏心轴转速与减小间隙值均可减小破碎机动颚轴承滚子与内外滚道的碰撞力,增强运行稳定性及提高轴承寿命;增加偏心轴转速还可减少轴承的不规则磨损。对于PE150×250颚式破碎机,在提高生产率的同时减弱破碎机中的冲击现象,选择38 rad/s的转速最佳。

基于模糊PID控制的粉碎机转速和位置自适应控制研究

为提高粉碎机的控制性能,提出一种基于模糊PID控制的粉碎机转速和位置自适应控制算法。方法以粉碎机STM86步进电机控制为研究对象,构建粉碎机驱动电机数学模型,并结合PID控制和模糊控制设计基于模糊PID控制算法,以实现粉碎机的自适应控制。结果表明,模糊PID控制算法对粉碎机速度和位置控制的超调量分别为4.20%和0.13%,调节时间分别为0.21 s和0.02 s、平均跟随误差分别为0.02 mm和0.01 r/min;相较于PID控制、模糊滑模控制、模糊自抗干扰控制算法,模糊PID控制算法具有更低的超调量,更短的调节时间和更小的平均跟随误差。由此得出,模糊PID控制方法可实现更优异的粉碎机自适应控制,且具有一定的实际应用价值。

锤式破碎机冲击速率对青砂岩破碎效果及断裂能利用效率的影响

锤式破碎机冲击速率直接影响着岩石破碎效果,为研究锤头冲击速率对青砂岩破碎效果及断裂能利用效率的影响,结合物理试验与细观参数标定,建立了青砂岩宏观−细观力学响应关系,采用颗粒流程序分析了锤式破碎机不同冲击速率下青砂岩的应力链特点、损伤劣化特征、声发射及裂纹变化,并研究了断裂能利用效率。结果表明:①青砂岩在破碎过程中,破坏微单元内部以拉力链为主,破坏边缘以压力链为主,在未破坏微单元内部压力链与拉力链相互交叉成网状,拉力链引起裂纹扩展,最终破坏是压力链和拉力链共同作用的结果。②青砂岩破坏形态分为局部破坏、扩展破坏及加剧破坏阶段,破坏微单元数量分为快速增加、逐渐变缓及稳定阶段。冲击速率越大,破坏微单元数量稳定值增加幅度越大,且破坏微单元数量与冲击速率近似服从直线分布。③随着冲击速率的增加,青砂岩裂纹累计数量分为快速增加与稳定阶段。裂纹萌生阶段,以剪切裂纹为主,初始输入能量主要用于剪切裂纹的生成,而后拉伸裂纹所占的比例逐渐增加,且最终以拉伸裂纹为主。④青砂岩在破坏过程中,断裂能分为快速增加、逐渐变缓及稳定阶段。断裂能利用效率分为快速增加、缓慢增加及缓慢下降阶段,最大值为10.851%,并建立了断裂能利用效率与冲击速率的定量化关系。研究结果不仅从细观角度对青砂岩破碎效果及断裂能利用效率进行了初步探索,也可为锤式破碎机破碎过程中工艺参数的合理选择提供参考。

膜杂捆料多级破碎机设计与试验

针对棉田机收膜杂捆料中膜-土-秆分布不均、相互裹绕且体积过大,无法直接进行有效破碎的问题,通过分析膜杂捆料的破碎过程,确定了一种先破捆、再破碎的破碎方案,并设计了一种包含均匀喂料装置、直刀破捆装置、Y型甩刀破碎装置的膜杂捆料多级破碎机。以破碎刀辊转速、喂入速度、定刀数量作为主要影响因素,以残膜破碎合格率作为评价指标,进行三因素三水平试验,确定优化参数指标为试验在破碎刀辊转速1 125 r/min;喂入速度为0.012 m/s;定刀数量1个的因素水平下,此时膜杂捆料破碎合格率达到75.15%,满足后续加工工艺要求。该装置的研究对残膜资源化利用关键技术问题具有重要意义和应用价值。

水泥环破碎器矩形异形活塞密封性能分析

针对传统圆柱形液压活塞承载力不足问题,提出一种矩形异形活塞,研究其在不同工况下的密封性能。基于Abaqus软件建立异形活塞有限元模型,研究介质压力、密封间隙、活塞运动状态以及摩擦因数对密封性能的影响,并分析异形密封环不同位置处的应力分布和翻转情况。结果显示:静密封时,介质压力越大,密封环的最大Mises应力和最大接触应力越大;密封间隙越小,最大Mises应力与最大接触应力越大;相比静密封,内行程过程中最大Mises应力和最大接触应力都有明显增加,且随摩擦因数增加而增加,而外行程中最大Mises应力和最大接触应力相比静密封差异较小;各工况下应力最大值均出现在密封环圆弧段;在活塞运动过程中密封圈并未发生翻转,只是存在位置的平移情况。研究结果证明了异形活塞的可行性以及良好的密封性能,为活塞结构设计与优化提供了依据。

基于修正Manson-Halford模型的破碎机销轴疲劳分析

以双级锤式破碎机为研究对象,考虑销轴所受载荷的加载次序和载荷之间相互作用对销轴疲劳损伤的影响,对Manson-Halford(M-H)非线性疲劳损伤模型进行了修正,并通过试验数据验证了修正后模型的准确性和可靠性;考虑到破碎过程中锤头与销轴之间存在的非线性碰撞接触和物料颗粒对销轴受力的影响,利用MFBD-DEM双向耦合的方法获取了销轴的动态载荷;最后基于修正后M-H模型对销轴进行了疲劳分析。结果表明,与现有模型相比修正后的M-H模型寿命预测的误差最小;基于修正后M-H模型计算得到销轴的最小疲劳寿命为9.918×10^(6)次(165 h);利用MFBD-DEM双向耦合方法对双级锤式破碎机等大型破碎设备进行疲劳分析是合理可行的。

新型饲草揉碎机可靠性预测与分配的研究

试验针对新型饲草揉碎机工作过程中普遍存在关键零部件故障率较高且整机可靠性较低的问题,采用专家评分法对饲草揉碎机进行可靠性预测,改进综合因素法(IFM)进行可靠性分配。结果显示,饲草揉碎机可靠性预测值为0.668,无法满足我国饲草揉碎机可靠性标准要求。基于预测结果对可靠性进行重新分配,为转子与动力传动部分分配了较低的失效率权重、较高的可靠度;为揉碎机机体分配了较高的失效率权重、较低的可靠度。重新分配各子系统可靠度后,整机的可靠度为0.90259,满足饲草揉碎机系统可靠性要求。研究表明,研究可为饲草加工机械可靠性预测与分配提供方法参考。

基于因果模型的破碎机故障树自动构建方法

圆锥破碎机的安全运行是矿山正常生产的前提,利用故障树对其进行可靠性分析是十分必要的。传统的完全基于专家经验构建故障树的方法自动化程度低,系统迭代升级后需要重新进行安全检查,故障树维护成本高。为了解决上述问题,提出了一种基于因果模型的圆锥破碎机故障树自动构建方法。首先,通过部件故障之间的因果关系检查,将圆锥破碎机无向图转换为对应故障下的有向图;然后,基于此有向图,利用图遍历方法和模块图设计模式自动构建故障树结构。将所提方法应用到实际的圆锥破碎机生产率故障树构建中,应用结果证明了所提方法的实用性和有效性。基于此故障树构建的圆锥破碎机故障自动诊断系统在东鞍山露天矿的实际应用中起到了有效的辅助诊断作用。

一种饲料粉碎机自动化加工控制技术研究

针对传统锤片式饲料粉碎机存在粉碎能耗高和粉碎效果差,导致饲料生成率低的问题,提出一种基于神经网络的自适应PID粉碎机控制方法NN-PID。首先,确定神经网络结构和粉碎机相关参数;然后将神经网络算法输入至S函数中,通过MATLAB-Simulink图形化编程模块构建一个饲料粉碎机粉碎系统PID控制模型;最后通过仿真软件对构建的控制模型进行仿真验证。实验结果表明,在输入为R=1的阶跃信号时,通过该模型进行控制后,饲料粉碎机控制系统上升时间取值为0.662 s、峰值时间为0.987 s,最大超调量为0.044%,调整时间为1.447 s。相较于传统的T-PID模型和F-PID模型,该模型的控制准确性更高,稳定性和鲁棒性更强,在四个性能评价指标中的性能更为优越。由此说明,该模型可降低锤片式饲料粉碎机的粉碎能耗,提升粉碎效果和生产率,满足饲料粉碎机控制系统的自动化控制需求。

静态破碎剂水化释压升温过程的影响因素分析

为探究影响爆破用静态破碎剂水化反应过程中膨胀压力与温度变化的外部因素,基于多水平正交实验进行静态破碎剂的配方优化设计,利用“外管法”测试静态破碎剂膨胀压力,使用温度计探针实时监测破碎剂水化反应温度。从不同水灰比、不同环境温度、不同拌合水温三个方面对静态破碎剂进行水化反应分析研究,结果表明:静态破碎剂反应的峰值温度随水灰比的增加而先增加后降低;随环境温度以及拌合水温的升高而升高,整体水化反应温度经历“平缓—急剧升温—快速降温”的过程;静态破碎剂在测试钢管中的峰值压力随水灰比增大而呈现先增大后减小的趋势,随环境温度升高而升高,但温度过高易导致破碎剂喷孔使膨胀压急剧降低直至失去膨胀力。适当提高拌合水温对静态破碎剂水化反应起促进作用,拌合水温不宜高于35℃。

美卓HP800圆锥破碎机常见故障及处理方法

针对美卓HP800圆锥破碎机常见故障进行了全面、深入的研究,包括机械、液压和电控系统的故障类型,并依据多学科理论如轴承学、流体力学和电子工程,结合实际操作经验,提出了一系列具有针对性和高实用性的解决方案。这些措施有效减少了设备的停机时间,显著提高了整体系统的可靠性和效率,为设备生产的稳定性提供了科学依据,有助于推动相关企业和技术人员在设备管理和维护方面达到更高的工作水平,对矿山设备管理和维护实践具有重要参考价值。