Study On The Performance Of Cyclone Separator With Limiter

Cyclone separator is often used in gas-solid fluidized bed system for separation and recovery of circulating catalysts.The separator sends the catalysts back to the fluidized bed through the dipleg to participate in gas-solid reaction.In order to ensure the normal discharge and sealing of diplegs in industry,the length of diplegs is longer,which indirectly leads to the limited design height of main separation space of cyclone separator,and then affects the performance of cyclone separator.In view of the above problems,the previous studies show that the installation of a limiter can reduce the dipleg drag force,but the reduction of dipleg drag force has not been clearly explained,and the impact of the limiter on the performance of the separator is also controversial.In this paper,the effects of cyclone arrester on the dipleg drag force,pressure drop and efficiency of cyclone are investigated through experiments and simulations.The research contents and conclusions are as follows:(1)Experiments and simulations of separators with and without plate limiters were carried out.The results show that the installation of plate limiters can reduce the dipleg drag force,about 20%-30%,increase the pressure drop of the separators about 100 Pa and reduce the separation efficiency.The analysis of the flow field inside the separator shows that the installation of a limiter near the end of vortex tail can restrain the further downward extension of the swing of the vortex tail,control the swing of the vortex core in the legs and weaken the rotational strength of the air flow.To reduce the suction force of diplegs,and the installation of the plate limiter makes the airflow passing through the space impact the surface of the plate limiter,increasing the energy loss,increasing the pressure drop to a certain extent,but the increase is not significant;the large upstream flow in the expansion bin space drives the partially separated particles back into the internal swirl flow and reduces the separation efficiency.(2)In order to alleviate the problem of lower separation efficiency,the method of increasing the height of the cylinder is adopted to compensate for the efficiency.When the height of the cylinder increases to a certain extent,it can meet the requirements of reducing the pulling force of the legs,reducing the pressure drop and ensuring the separation efficiency does not decrease.(3)Combining with the previous mathematical models,the correlation formulas between dipleg drag force,pressure drop,efficiency and cylinder structure parameters,inlet gas velocity are established.With the help of dimension theory and origin 8.0 plotting software,the correlation formulas are solved,and the performance of cyclone separator with or without plate limiter structure is obtained,which is in good agreement with the experimental values,and provides a basis for the performance comparison of the subsequent research of limiters.(4)The structure of the limiter itself also has some influence on the separation performance.Because the apex cone limiter can make the air flow rotate on the surface of the cone,it has more obvious influence on reducing the pulling force of the legs and ensuring the efficiency than the impact of the plate limiter,and the increase of the pressure drop is smaller.The structure of the central hole blockage weakens the air flow in the space below the limiter more.The strength of center rotation reduces the dipleg drag force.