Design And Experimental Study Of Self-adjusting Slotted Distributor Fluidized Bed

Fluidization technology is widely used in chemical industry,metallurgy,energy,materials,environment and other fields due to its effective mass and heat transfer characteristics.Fluidized bed equipment made of fluidization technology is mostly used in drying,combustion and other processes.For the fluidized bed,the gas-solid fluidized bed is more widely used,and the gas distribution plate is the key component of the gas-solid fluidized bed,which not only supports the material,but also realizes the functions of uniform gas distribution.In the current research,most of the gas distributor with different structures and functions are studied,and few of them are dynamic.In order to make the gas distributor distribute the air more evenly,and realize the automatic adjustment in the fluidization process according to the actual fluidization needs,so as to adapt to a wider fluidization medium,In this study,a new type of gas distributor,the slit distributor with variable opening rate,is designed.The distributor adopts a double-layer structure,through the guide rail structure,the lower distributor realizes the relative movement to the upper distributor,so as to change the opening rate of the distributor and achieve the dynamic change effect.It is found that the pressure drop of the distributor increases with the increase of the wind speed.When the opening ratio of the distributor is 2.9%,the pressure drop of gas passing through the distributor is large.When the opening rate of the distributor increases from 2.9%to 11.4%,the pressure drop of the distributor decreases with the increase of the opening rate of the distributor at different wind speeds.Based on the slotted distribution plate with variable opening rate,the fluidization effect of Geldart class D particles was studied in a fluidized bed.It was found that the minimum fluidization speed of particles entering the fluidized bed stage was slightly different under different opening rate.In the fixed bed stage,when the opening rate of distribution plate was 8.6%,the bed pressure drop was the largest and the critical fluidization speed was the smallest,about 0.9 m/s.When the opening ratio is 2.9%,the bed pressure drop is the lowest and the critical velocity is the highest,about 1.1 m/s.Through the regression analysis of the test data,not only the relationship between the pressure drop and the gas velocity under the different opening rate of the distribution plate is qualitatively analyzed,but also the modified equation of Ergun formula is obtained quantitatively,and the self-regulation control system is designed.