Studies On The Dust Removal Performance Of Granular Desulphurization Reagent

In the paper, granular filtration theory was presented, and on the basis of predecessor's research results, the model of calculating collection efficiency and pressure loss during non-stationary filtration was established. The model as far as possible contained the parameters that affected granular layer filtration, and reflected the effect of dust deposition on collection efficiency and pressure loss.The effect of the thickness of filter layer, the filtration gas velocity and filter-grain diameter on dust-removing efficiency and pressure loss was investigated in the fixed-bed filter with granular desulphurization reagent. The experiment indicated that, under the appropriate operating condition, the column desulphurization reagent filter could operate at high collection efficiencies,typically exceeding 99%, and low pressure loss.Experiments carried out in the fixed-bed filter under the condition of 0.3m. s~-1 of the superficial gas velocity, 0.6mm of filter-grain diameter and 0.25m, 0.4m, 0.8m of thickness of filter layer respectively showed the effect of the thickness of the filter layer on pressure loss and runtime was obvious. When the thickness exceeded a certain limit, the effect on dust-removing efficiency could become insignificant. For desirable dust-removing efficiency and pressure loss, the suitable thickness of filter layer should be between 0.4m-0.8m.Experiments under the condition of 0.6mm of filter-grain diameter, 0.4m of thickness of filter layer showed when the superficial gas velocity was respectively 0.3 m. s~-1 and 0.4 m. s~-1, the dust-removing efficiency was 99% or more. The dust-removing efficiency was lower when the velocity was 0.48 m. s~-1.In different filter-grain diameter experiments, comparing the efficiency curve of 6mm with one of 8mm showed that the former seemed moderataly stable, but in the latter undulation was big.It was discovered through the experiment that the filtration process of the fixed-bed filter could been divided into three stages, namely rise stage of the dust-removing efficiency, stable stage and drop stage. In the rise stage, the deposition dust obviously improved the dust-removing efficiency, and enabled efficiency to achieve the high stable stage from the low initial efficiency in a short time.In the third stage, the dust content achieved the biggest content of granular layer. The granular layer was penetrated, and the dust removal efficiency dropped.On the basis of fixed bed filter experiment ,the effect of filter media flow rate on collection efficiency of the moving granular bed filter were investigated experimentally.