Cold model experiments on gas-solid separation performance of granules moving bed

Pyrolysis as the first step of coal quality conversion technology can achieve efficient utilization of coal under mild conditions, in which the purification of dust-containing pyrolysis gas is one of the key problems to be solved in the large-scale application of this tech¬nology. The granular bed filtration technology has the advantages of high filtration efficiency and low filter material cost. In order to investi¬gate the filtration effectiveness of the granules moving bed for dust removal from pulverized coal pyrolysis gas,wheat was selected as the fil¬ter medium for the cold test,and silica gel powder was used as the experimental dust. The influence of various operating conditions on the filtration efficiency and dust removal efficiency were investigated on a self-designed cold test platform. The results show that the order of influencing factors of filtration efficiency following:apparent speed of wind > thickness of filtration layer >blanking speed of filter material; the filtration efficiency decreases with the increase of apparent wind speed and increases with the rise in filter layer thickness. When the thickness of the filter layer increases to more than 200 mm,the filter efficiency changes is small;while,the blanking speed of the filter ma¬terial increases,the filter efficiency decreases. After the dust particle size reaches to 10 |xm,the filtration efficiency can basically be main-tained at 98%. Under optimized filtration conditions:the thickness of the filter layer is 300 mm,the feeding speed of the filter material is 0.002 m/s,the filtration time is 10 min,the best filtration efficiency can reach to 98.1%. The experimental results not only realize the pre¬diction of the filtration performance of the granules moving bed at room temperature, but also provide a reference basis for designing the hot state dust removal device for pulverized coal pyrolysis.