旋流器超细分级及离心重选试验研究

发布时间：2019-06-17 18:11

【摘要】：利用Falcon离心分选机可以实现对细粒煤进行低成本、无污染的高效脱硫降灰,但是-0.045mm粒级高灰细泥容易越过溢流堰进入精煤,造成精煤污染,影响分选效果。本文采用KREBS分级旋流器对细粒煤进行超细分级,并对分级旋流器底流产品进行强化重力场分选试验。利用软件进行试验方案优化最终得到在入料压力为0.03MPa,补加水压0.02MPa,入料浓度为12.50%的操作参数下,最终可以得到91.32%的分级效率。适当的增加入料压力不仅可以降低底流中细粒级的含量,同时可以减少溢流中的跑粗;在入料压力增大到一定程度之前(本次试验研究入料压力界限为0.04MPa),随着入料压力的增加,分级粒度减小,分级效率以及分级精度升高,超过0.04MPa之后,干扰沉降作用加剧,分级效率及分级精度下降。相较与无冲洗水,有冲洗水的条件下可以有效降低底流中细粒级含量,但是冲洗水的添加也会造成临近粒级在溢流中跑粗,并且分级粒度随着冲洗压力的增加而增大;过高的入料浓度会使颗粒因底流浓度过高,造成干扰沉降作用加大,分级粒度增大,分级效率降低;通过试验优化以及验证最终得到旋流器超细分级试验优化参数组合为:入料压力0.03MPa,冲洗水压力0.02MPa,入料浓度12.50%,此时分级效率为91.32%,并且得到分级效率与操作参数之间的函数关系;在精煤灰分要求不高于8%的条件下,Falcon离心分选最终的优化操作参数组合为:转动频率19.02HZ,反冲水压0.02MPa,入料浓度15%。
[Abstract]:Falcon centrifugal separator can realize low cost and no pollution high efficiency desulphurization and ash reduction of fine coal, but-0.045mm high ash fine mud is easy to cross overflow Weir into clean coal, resulting in clean coal pollution and affecting the separation effect. In this paper, KREBS classification cyclone is used to classify fine coal, and the gravity field separation test is carried out on the bottom flow products of the classification cyclone. When the feeding pressure is 0.03 MPA, the water pressure is 0.02 MPA and the feeding concentration is 12.50%, the classification efficiency can be obtained by using the software to optimize the test scheme. Properly increasing the feeding pressure can not only reduce the content of fine particles in the bottom flow, but also reduce the running diameter in the overflow. Before the feeding pressure increases to a certain extent (the feeding pressure limit is 0.04MPa), with the increase of the feeding pressure, the classification particle size decreases, the classification efficiency and classification accuracy increase, after exceeding 0.04MPa, the interference settlement is intensified, and the classification efficiency and classification accuracy decrease. Compared with the non-flushing water, the fine particle size content in the bottom flow can be effectively reduced under the condition of flushing water, but the addition of flushing water will also cause the adjacent grain size to run thicker in the overflow, and the grading particle size will increase with the increase of flushing pressure, too high feed concentration will cause the particles to interfere with and settle, the classification particle size will increase, and the classification efficiency will decrease. Through experimental optimization and verification, the optimal parameter combination of ultra-fine classification test of cyclone is obtained as follows: feeding pressure 0.03 MPA, flushing water pressure 0.02 MPA, feed concentration 12.50%, classification efficiency 91.32%, and the functional relationship between classification efficiency and operation parameters is obtained. Under the condition that the ash content of clean coal is not more than 8%, the final optimal operation parameter combination of Falcon centrifugal separation is as follows: rotation frequency 19.02HZ, recoil water pressure 0.02MPA, feed concentration 15%.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD94;TD922

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