| The filtration mechanisms and the characteristics of the hot gas ceramicfilter for advanced coal-fired combined cycles are studied. The resultant theoryand method are given to design and optimize the ceramic filter element.The concept of "the minimum thickness in actual grading"was putforward on the basis of the analyses of factors that affect the performance of theceramic filter element. The base and method of optimization design for theceramic filter element are provided.The effects of some flow and structure parameters on the filtrationefficiency and pressure drop of the ceramic filter are analyzed. The resultsshow that the filtering medium made of the ceramic particles whose diametersare about 20 μm leads to excellent grading filter efficiency for the dust particleswhose diameters are 5 μm or so, and the pressure drop is not too large, therelated minimal thickness of the actual grading is of the order of hundreds ofμm. Such a kind of ceramic filter medium is suitable for the hot gas ceramicfilter used in IGCC.On the Basis of the analyses of a series of formulae on the variablefraction void vacuum (FVV), the velocity in void vacuum and the pressure dropbetween the inner and outer surface of the element along the axis, an idea aboutthe FVV of the ceramic medium along the axis of the ceramic filter elementwas first put forward. It is, maybe, of value to apply the variable FVV along theaxis of the ceramic filter element in order to reduce or eliminate the "bridging"phenomena of the dust among the ceramic filter elements.The experimental setup of the ceramic filter was improved. Thecalibration test of the screw feeder of tiny solid particles indicates that the fluxcan be accurately controlled between 0.1g/min to 5g/min for the Shenmu coalpowders of average diameter 20 μm or so, it can be also accurately controlledin the range of 0.3g/min to 16g/min for the quartz powder of average diameter10 μm or so.The experimental results show that the pressure drop and velocity in the...
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