振动筛双层隔振系统的设计研究

针对大型直线振动筛振动剧烈,噪声大的缺点,分析振动筛的振动噪声特性,根据引入双层隔振理论,提出振动筛隔振设计方案,建立振动微分方程。应用功率流法推导出受到简谐激振力隔振系统的动力传递特性,并应用Matlab软件完成振动筛双层隔振的仿真分析。应用结果证明本设计方案切实可行。     

振动筛的一、二次隔振与反共振技术的应用

振动筛是近些年来全国各洗煤厂对物料进行筛分,以及对选后产品进行脱水与脱介的必要机械设备之一。通常使用一、二次隔振以减少其工作时对地基的动负荷及其所产生的噪音。普通一次隔振振动筛的隔振装置可以减小其带给地基振动的85%~90%,二次隔振振动筛的隔振效果甚至可以达到90%~95%。反共振机械因为有其独特的反共振原理,可以很好地满足系统对振动频率、幅值的要求,并减少对地基的损害以及工作噪声。反共振振动机械在工作时传给基础的动负荷,可以比普通一次隔振振动筛减小大约57%,甚至比一般的二次隔振振动筛还要小。     

改造振动筛隔振系统 消除筛分楼共振现象

简要介绍了朱仙庄煤矿选煤厂的概况及二次重介工艺技术改造的基本情况,阐述了DL30100型振动筛的主要技术参数,分析了该振动筛隔振系统存在的问题和筛分楼产生共振的危害。通过改造该振动筛的隔振系统,即改造一次隔振系统、加装减振梁和改造二次隔振系统,可消除筛分楼的共振现象。     

附加气室空气弹簧隔振的振动筛动力学建模与分析

附加气室空气弹簧在两个气室之间设有节流元件,可吸收振动的能量,具有良好的阻尼特性。作为一种新型隔振元件,附加气室空气弹簧能缩短振动筛过共振区时间,减小共振振幅及附加倾摆运动,提高振动筛运行的平稳性。分析振动筛二自由度动力学模型,并求解运动学微分方程,发现振动筛实际振动方向角不等于激振力作用方向角,振幅和抛掷指数也可用单自由度模型表征;利用热力学和流体力学理论建立附加气室空气弹簧的线性模型,得到其刚度阻尼的表达式,基于此,推导出附加气室空气弹簧的振动筛动力学模型,并建立运动学微分方程;搭建附加气室空气弹簧隔振系统和振动实验台,测试实验台的运动学参数;在MATLAB/Simulink环境下对所建动力学模型进行仿真研究,并与实验台测试结果进行了比较分析。结果表明:模型仿真振幅为5.321 mm,实验测试的稳态振幅为5.372 mm,二者误差仅为1%,具有较高的准确性。模型仿真结果显示:电机转速对振幅影响较小,对抛掷指数影响较大,随着电机转速由840 r/min增加到990 r/min时,振幅由4.549 mm降为4.427 mm,抛掷指数由3.6上升到4.9;改变隔振系统的初始气压可以调节振...     

固相颗粒振动筛的设计与研究

在现场工艺试验的基础上,对固相颗粒直线型振动筛进行了结构上的设计与改进。新型振动筛设计了3排软弹簧隔振支撑系统、筛箱固定装置、卷轴式筛网绷紧装置、卡瓦锁紧机构及筛箱倾角调节装置,筛网安装调整方便、绷紧均匀,提高了产品一次筛分率,降低了振动筛的动载荷,大幅度提高了筛网、轴承等零件的使用寿命。     

混沌振动筛振幅与阻尼比的确定

根据动力吸振基本理论和混沌振动基本理论所提出的混沌动力吸振振动筛，在设计思想上突破了传统的激振形式与被动隔振方式，在结构上采用激振器与筛箱分离，振动能量通过弹     

液压波动激振机理及其在模拟振动筛中的应用

研究液压波动机理,建立以激波器为激振执行机构的激波器-液压缸激振系统,并将激振原理应用于模拟振动筛,解决现有惯性激振存在的问题。系统的激振原理是通过激波器的强制配流在液压管路中产生周期性的液压冲击波,从而使活塞、活塞杆及其固结的负载不断地振动。将激振原理应用于模拟振动筛,并进行试验,研究了模拟振动筛不同工况、不同参数的振动控制规律。试验结果表明：模拟振动筛的振动频率受激波器激振频率的独立控制,振幅大小可通过溢流阀来调节;振幅一定时,压力随激振频率的提高而增大;压力一定时,振幅随激振频率的增加而减小。     

弹性耦合激励振动筛的摆振研究

应用逆式动力吸振原理，研究了具有分布质量的弹性耦合激励振动筛的摆振问题，导质量对称分布时该筛的前六阶固有频率和对谐波激励响应的解析表达式，并讨论了结构参数对振动筛频响特性和基础动荷的影响。     

基于MATLAB的某型号振动筛设计参数的优化

振动筛的主要设计参数包括振动频率、振幅、振动面倾角、隔振系数、筛长和筛宽等,这些参数的优化是振动筛设计工作中极为重要的内容。以国内某型号单轴圆运动筛为例,对其进行运动学、动力学分析,建立一系列运动方程和力学模型,在MATLAB环境下对振动筛进行优化,并获得主要设计参数值。通过对比,优化后振动筛物料相对筛面的平均速度增大,物料下落时的冲击速度和振动筛传给地基的动载荷均减小,提高了振动筛使用性能。     

机载液压锚杆钻机隔振装置的设计

建立机载锚杆钻机的振动力学模型,确定动力参数,根据隔振的需要设计一种隔振装置,降低钻箱传递给机组的动载荷,以提高机组使用寿命。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

唐口煤矿深部复杂开采工作面瓦斯分源涌出规律研究

研究工作面瓦斯涌出规律对工作面瓦斯治理有重要意义。为了得到唐口煤矿深部3号煤层复杂开采条件下工作面回采时期瓦斯涌出时空演化规律,选取6304工作面作为对象,采用实测方法研究6304工作面瓦斯涌出规律。结果表明:6304工作面瓦斯涌出量为6.534 m³/min,其中煤壁占34.27%,落煤占29.62%,采空区占36.11%;沿工作面倾向由低到高,瓦斯浓度整体为上升趋势,其中1—76号架工作面瓦斯浓度小于0.20%,76—102号架瓦斯浓度上升明显,最大为0.387%;上隅角的后部采空区是工作面的瓦斯主要涌出源,上隅角1号测点瓦斯浓度0.78%,上隅角周边3号、5号、7号、8号、9号测点瓦斯浓度平均为0.643%;周期来压时,上隅角瓦斯相对平时较高。研究为针对性的瓦斯分源监控与灾害防治提供基础。