一种新型的摩擦分离机构

一种新型的摩擦分离机构邮电部第三研究所颜立锋一、摩擦分离装置的现状分离机构在邮政通信设备上应用广泛，在信函处理上又是一种必须采用的装置。目前信函的大量集中处理基本采用负压吸气附助摩擦阻尼的分离机构。而在信函分散过戳、盖销处理中则采用摩擦分离。摩擦分离...

一种油棕果壳破碎分离机设计

针对目前油棕果壳破壳不完全和壳仁分离不彻底导致棕仁油提炼不纯的问题,基于敲击式破壳机理和摩擦分离原理设计一种小型油棕果壳破碎分离机,通过分析计算确定滚筒的几何参数,打击机构的压缩弹簧的自由长度为95 mm、有效圈数为11圈以及分离机构的传送带与水平面的夹角为20°。利用含水率为14%,横向长度为15~17 mm,纵向长度为17.5~20 mm的油棕果壳进行破碎分离试验,试验结果:脱壳率为88.2%、分离率为79.7%。

汽车车轮模型的开发与仿真验证

针对现有轮胎模型应用中存在的不足,开发了考虑气胎弹性的汽车车轮模型。模型用六向弹簧阻尼器模拟了气胎的弹性,并为接地印迹块外力计算创造了条件,接地印迹块与地面的接触摩擦采用动静摩擦分离的建模方法进行建模,准确计算了车辆在零速度附近的受力。通过对零速度工况、原地转向工况、转向小干扰工况、操纵稳定性工况的仿真,验证了模型的正确性。

关于静电防护措施的探讨

根据多年实际工作阐述了卫星通信设备的实际维护维修工作经验,从实践上升到理论,并从实际应用的角度来描述静电防护措施,并提出相应的管理建议。

Dry coal fly ash cleaning using rotary triboelectrostatic separator

More than 80 million metric tons of fly ash is produced annually in the U.S. as coal combustion by-product. Coal fly ash can be converted to value-added products if unburned carbon is reduced to less than 2.5%. However, most of fly ash is currently landfilled as waste due to lack of efficient purification technologies to separate unburned carbon from fly ash. A rotary triboelectrostatic separator has been developed and patented recently at the University of Kentucky with unique features. Several fly ash samples have been used to understand the effects of major process parameters on the separation performance. The results show that compared to existing triboelectrostatic separators, the rotary triboelectrostatic separator has significant advantages in particle charging efficiency, solids throughput, separation efficiency, applicable particle size range.

Beneficiation study of Eshidiya phosphorites using a rotary triboelectrostatic separator

This study was performed to investigate the feasibility of applying a Rotary Triboelectrostatic Separator（RTS） to the beneficiation of Eshidiya phosphate minerals.RTS separation tests were carried out on phosphatic bed A_1,phosphatic bed A_3 and slime samples.The bed A_1 and slime samples were tested without desliming.Two sets of tests were performed using the A_3 sample： one was performed without desliming and the other with the A_3 sample deslimed.RTS separation tests as initially performed on the bed A_1 and slime samples gave products that had essentially the same P_2O_5 content.This indicated that adsorbed clay particles on the phosphate surface are responsible for the poor separation of un-deslimed phosphates.Better triboelectrostatic separation was observed with the undeslimed A_3 phosphate sample;these tests resulted in a highest product grade of 26%P_2O_5.The deslimed A_3 sample showed far more effective separation than the undeslimed A_3 one.In fact,a concentrate of 34%P_2O_5 was obtained from the triboelectrcstatic separation of deslimed A_3.The results indicate that with deslimed A_3 P_2O_5 recovery was about 65%for a concentrate of 28%P_2O_5 and about 45%for a concentrate of 30%P_2O_5.These results clearly show the importance of desliming for effective beneficiation of phosphate by the RTS.A more efficient separation can be expected from optimized operating conditions and circuit configuration.

Influence of Fine Sediment on the Fluidity of Debris Flows

Debris flows include a great diversity of grain sizes with inherent features such as inverse grading, particle size segregation, and liquefaction of fine sediment. The liquefaction of fine sediment affects the fluidity of debris flows, although the behavior and influence of fine sediment in debris flows have not been examined sufficiently. This study used flume tests to detect the effect of fine sediment on the fluidity of laboratory debris flows consisting of particles with various diameters. From the experiments, the greatest sediment concentration and flow depth were observed in the debris flows mixed with fine sediment indicating increased flow resistance. The experimental friction coefficient was then compared with the theoretical friction coefficient derived by substituting the experimental values into the constitutive equations for debris flow. The theoretical friction coefficient was obtained from two models with different fine-sediment treatments： assuming that all of the fine sediments were solid particles or that the particles consisted of a fluid phase involving pore water liquefaction. From the comparison of the friction coefficients, a fully liquefaction state was detected for the fine particle mixture. When the mixing ratio and particle size of the fine sediment were different, some other eases were considered to be in a partially liquefied transition state. These results imply that the liquefaction of fine sediment in debris flows was induced not only by the geometric conditions such as particle sizes, but also by the flow conditions.

Flexible PDMS-based triboelectric nanogenerator for instantaneous force sensing and human joint movement monitoring

Flexible wearable sensors with excellent electric response and self-powered capability have become an appealing hotspot for personal healthcare and human-machine interfaces.Here,based on triboelectric nanogenerator(TENG),a flexible self-powered tactile sensor composed of micro-frustum-arrays-structured polydimethylsiloxane(PDMS)film/copper(Cu)electrodes,and poly(vinylidenefluoride-trifluoroethylene)(P(VDF-TrFE))nanofibers has been demonstrated.The TENG-based self-powered tactile sensor can generate electrical signals through the contact-separation process of two triboelectric layers under external mechanical stimuli.Due to the uniform and controllable micro-frustum-arrays structure fabricated by micro-electro-mechanical system(MEMS)process and the P(VDF-TrFE)nanofibers fabricated by electrostatic spinning,the flexible PDMS-based sensor presents high sensitivity of 2.97 V kPa^-1,stability of 40,000 cycles(no significant decay),response time of 60 ms at 1 Hz,low detection pressure of a water drop(~4 Pa,35 mg)and good linearity of 0.99231 in low pressure region.Since the PDMS film presents ultra-flexibility and excellent-biocompatibility,the sensor can be comfortably attached on human body.Furthermore,the tactile sensor can recognize various types of human body movements by the corresponding electrical signals.Therefore,the as-prepared TENGs are potential on the prospects of gesture detection,health assessment,human-machine interfaces and so on.