| Due to lots of inhaled particles and heavy metals in the high temperature gas dusts were emitted form coal fired power generetion plants,it became increasingly serious air pollution of hightemperature gas dusts.it must be reduced them temperature and coolling treated,then these high temperature gas dusts could be dust-removalled and cleanned.At this moment,heat was lost,heat-utilizing was low,energy consuming was huge,and dust cleaning effect was bad,the routine methods of dust removal were not satisfacted with the rigorous standard environmental protection.Used porous ceramics to clean inhaled particles and heavy metals toxicants of new filtering ways had quite recognized.It took on excellent high temperature and high pressure resistance,good acid and alkali eorrosion resistance,high filtration efficiency and long service life.But its fetal weakness were lowly intensity,badly brittleness.Aimed at this issue,the paper was put forward to rein-forced porous ceramic relying on ceremic fiber rein-forced and zirconia transformation toughening mechanisms.The resultant theory and method are given to design and optimize the ceramic filter element.Firstly,This subject was used cold-simulation testing method to the actual environmental conditions,the filtration resistance and the filtration velocity was accorded with the linear law,and got the fitting curve.The filtering efficiency of the ceramic fiber products was also tested,The effect was not very good,some of the experimental data was negative,The reason that was the ceramic fiber products containing crystalline particles and microfibers.Secondly,using ceramic fiber products and the zirconia transformation toughening mechanism,with grouting film method,The'ratio of different samples and testing and firing process of ceramic fiber products.The zirconia toughened alumina,silica and kaolin ceramic matrix of porous ceramic filter material sample were created And silica,alumina,zirconia and kaolin four basic ceremic power materials were tested them performance,including the average sizes,size distributions and chemical contents.The thermal analysis of sintering bodies were studied by TG,DTA,DTG and DSC.In order to determine the sintered body,the XRD of four ceramic powders were applied,some samples taken place the zirconia martensitic transformation,which was the transformation toughening zirconia ceramic matrix changes.microstructure were analyzed and observed by SEM.But in the process of sintering,ceramic powders and some liquid phase filled and blocked among the aggregate pores,water absorption, density,porosity were also tested,density was 1.0094-1.8255g/cm~3;water absorp tion was 20-60%,Mainly sample porosity was 30%-70%,bending strength was 3.5MPa, compressive strength was 16 MPa.The sintering strength with the sintering time,the slow increase in bending strength and compressive strength to increase significantly.By drying the sample and rate of change sintering line test for the performance of the overall direction of the width of the length of the shrinkage and the thickness direction of expansion.By sintering body after apparent density test,the apparent density was 0.34～0.84g/cm~3,whicf was meeted the high-porous ceramic filter results.With the sintering temperature and holding time of the extension,the porosity of the sample showed a gradual downward trend,ceramic sintered slow increase in strength,porosity loss increased to reduce the porosity.Finally,the composite ceramic filter materials were tested by colding-state,filters pressure and wind speeds was accorded with the quadratic law,ceramic filter through the filter efficiency of the board of the test.Filtration efficiency of 30%-40%,although the effect of filtering is not optimal,yet to some extent to the strength of materials and mechanical properties improved.Preparation of the porous ceramic filter had its innovations and improvements,the study has some significance great economical value in heat utilization and extensive applications foreground. |
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