Effect of louver baffle on the stability and separation performance of the gas-solid separation fluidized bed

Bed density stability is often the dominant factor restricting the efficiency of coal beneficiation in gas-solid separation fluidized beds (GSSFB). Here, in order to improve the fluidization quality, a louver baffle was introduced into a conventional GSSFB, converting it into a so-called louver baffle separation fluidized bed (LBSFB). The influence of the louver baffle on the flui-dization characteristics and coal separation efficiency of the GSSFB were investigated using a combination of experiments and numerical simulations. The minimum fluidized gas velocity, pressure drop, and cross section density of the bed were measured when baffle was placed at two different positions (H=40 mm and H=80 mm). Meanwhile, the evolution of bubble gen-eration and particle flow were simulated when the baffle was placed at H= 40 mm and the operating gas velocity was 7.52 cm/s. The results showed that the use of a single guide baffle could effectively break up the bubbles in the bed, inhibit bubble growth and particle back-mixing, and restore the uniform distribution of the updraft. When the louver baffle was in-stalled at a height of H = 40 mm and the superficial gas velocity was 7.52 cm/s, the standard deviation of radial density fluctuation in the bed was reduced to 0.028 g/cm3, which is more than 35% lower than that of the conventional GSSFB, and that of the axial density fluctuation was reduced to 0.146 g/cm3. Under these conditions, the separation of 6-13 mm raw coal in a LBSFB resulted in a clean coal yield of 69.97% and a probable error, E, value of 0.082 g/cm3 (c) 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.

Automated summary

The introduction of a louver baffle can effectively improve the fluidization quality and coal beneficiation efficiency in gas-solid separation fluidized beds. Experimental and numerical simulation results show that a single guide baffle can effectively break up bubbles, inhibit bubble growth and particle back-mixing, and restore the uniform distribution of the updraft. Under specific conditions, the use of a louver baffle reduces the standard deviation of radial density fluctuation in the bed to 0.028 g/cm3, which is more than 35% lower than that of the conventional GSSFB, and reduces the standard deviation of axial density fluctuation to 0.146 g/cm3. Under these conditions, the separation of 6-13 mm raw coal in a LBSFB resulted in a clean coal yield of 69.97% and a probable error, E, value of 0.082 g/cm3.