溢流直连三产品旋流器消涡装置与方法研究

发布时间：2018-03-03 10:23

本文选题：旋流器　切入点：串联　出处：《太原理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：旋流器作为一种分离设备在选煤、化工、环保等工业领域有着广泛的应用，因为它具有结构简单、易于操作、低占用面积、可靠耐用、零转动部件且便于维修等优点。有时，为了工业生产的需要或者达到某些特定目的，需要将多个旋流器组合使用，例如串联、并联等。如果需要对某个旋流器的溢流产品继续分选或者分级，，则需要在该旋流器溢流出口串联相应的旋流器，以继续进行分选或者分级，该两段旋流器系统通常被称为溢流直连的三产品旋流器系统。溢流直连的三产品旋流器系统存在的一个根本问题是一段旋流器的溢流往往是高速旋转的涡流，而这种涡流将对二段旋流器的分选/分级性能产生何种影响则较少有学者涉及。由于溢流直连的三产品旋流器系统在很多作业单位存在应用，研究涡流入料对旋流器分选/分级性能的影响以及如何消除一段旋流器溢流的涡流、提高溢流直连的三产品旋流器系统总体的工艺性能是十分有必要的。本研究首先利用特定的装置（实际为入口规格不同、底流口封死的两个分选旋流器）产生了两种涡流强度不同的溢流，将它们作为分级旋流器的入料，连同直流入料的情况，共得到三种不同涡流强度入料（流量相同）条件下分级旋流器的分级效果。比较得到的分级曲线发现，分级旋流器的分级性能随着入料涡流强度的增大而降低。在搞清涡流入料对旋流器分级性能的危害以后，一十字叶片装置被安装在一段分选旋流器与二段分级旋流器之间的连接管路中，以图消除一段溢流的涡流、提高二段分级效率和提高该三产品旋流器系统的总体工艺性能。试验结果表明，十字叶片装置可有效消除一段溢流的涡流、提高二段分级效率，然而，它也会对一段溢流造成一定的阻力、导致一段底流口出料量加大。针对十字叶片装置对一段溢流阻力较大的问题，我们设计了两种新型的螺旋导流叶片装置，一为空心十字叶片，另一为螺旋导流叶片。试验结果表明，就二段分级旋流器分级效果而言，在粗颗粒分级效率都接近100%的前提下，安装螺旋导流叶片底流细粒夹带现象更轻，同时，螺旋导流叶片对一段溢流造成的阻力相对较小，综合这两方面来看，所设计螺旋导流叶片是一种性能更加优异的导流装置；而所设计的空心管结构并未表现出在减小一段溢流阻力方面的优越性，螺旋叶片相比于直叶片在减小对一段溢流阻力方面表现出一定的优越性。在螺旋导流叶片阻力相对较小的情况下，通过改变一段旋流器结构（增大锥角、缩小底流口等），实现一段底流出料量与不加导流叶片时基本一致、二段分级性能大幅度提升从而提升整个三产品旋流器系统的想法是完全可行的。同时，CFD数值模拟技术被用来对“入料涡流强度对旋流器分级性能的影响”和“不同导流叶片的消涡效果”进行数值模拟，发现：分级旋流器流场中的切向速度显著降低和流场的不稳定性是涡流入料导致分级旋流器分级性能下降的根本原因；而由于导流叶片阻力导致的一段旋流器流场中的下降流加强是其导致一段底流出料量加大的根本原因。数值模拟的结果很好的解释和印证了试验现象。
[Abstract]:As a kind of cyclone separation equipment in coal, chemical industry, environmental protection and other industrial fields have a wide range of applications, because it has the advantages of simple structure, easy operation, low occupancy area, reliable and durable, zero rotating parts and the advantages of easy maintenance. Sometimes, the needs of industrial production or to achieve certain goals, needs to be more than the hydrocyclone used in combination, such as series, parallel and so on. If you need a product of overflow cyclone sorting or grading will need to continue, in the hydrocyclone overflow outlet cyclone series corresponding, to continue sorting or grading, the two section cyclone system is often referred to as the three product cyclone overflow direct system a fundamental problem. There are three product cyclone overflow system is directly connected to a cyclone overflow is often high rotational, and this will be on the two stage separation / vortex cyclone classification The performance impact of few scholars involved. The three product cyclone overflow direct application in many existing operating units, research on the eddy current feeding on hydrocyclone separation / classification performance and how to eliminate the influence of a vortex cyclone overflow, overflow straight even improve the three product cyclone system overall process performance it is very necessary.
In this study, using a specific device (the actual entrance for different specifications, underflow sealed two separation hydrocyclone) produced two different overflow swirl intensity, feeding them as classifying cyclone, together with DC feed, there are three different swirl intensity (feed flow rate at the same) grading efficiency of cyclone conditions. By comparing the grading curve showed that the classification performance of classifying cyclone decreases with increasing feeding swirl intensity.
After feeding to eddy harm to the classification performance of the cyclone, a connecting pipe cross blade device is installed between a separation hydrocyclone and hydrocyclone in the two step, in order to remove a vortex of flooding, improve the efficiency of two stage classification and improve the overall process performance of the three product cyclone system. The test results show that the cross blade device can effectively eliminate the eddy overflow, improve the efficiency of two stage classification, however, it will also cause some resistance to a section of the overflow, underflow discharge leads to a volume increase.
The leaves on a larger cross device overflow resistance problems, we designed two kinds of spiral guide vane device of the utility model, a hollow cross blade, a spiral guide vane. The experimental results show that the two step cyclone effect, in the premise of coarse efficiency is close to 100%. Installation of spiral guide vane underflow fine entrainment phenomenon is lighter, at the same time, resulting in a spiral guide vane of overflow resistance is relatively small, the combination of these two aspects, the design of the spiral guide vane is the guiding device of a more excellent performance; and the design of the hollow tube structure did not show superiority in reducing a relief the resistance of the spiral blade compared to the straight blade in a decrease of the overflow resistance showed certain advantages. The spiral guide vane resistance is relatively small, the A variable structure (the hydrocyclone cone angle increases, reduce the underflow etc.), to achieve a bottom discharge amount is consistent with and without guide vanes, two segment classification performance is greatly improved so as to enhance the entire three product cyclone system idea is feasible.
At the same time, CFD numerical simulation technology is used to influence feeding swirl intensity on the classification performance of the cyclone and different guide vane vortex suppression effect was simulated, found that the flow field of classifying cyclone in the tangential velocity decreased and flow instability is the root cause of eddy current feed grade flow decrease for the performance of the classifier; and because of the decline of a guide vane cyclone flow field resistance led to the flow of strengthening is the lead to a fundamental reason to increase the amount of material flows out from the bottom. The numerical simulation results well explain and confirm the experimental phenomena.

【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD94;TD455

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