Experimental study on the pressure wave attenuation across gas-solid fluidized bed by single bubble injection

In this paper attenuation of the pressure wave has been studied for understanding the nature of pressure wave propagation in a gas-solid fluidized bed. The important aspect of the present work is to obtain more insights about the trend of the attenuation of the pressure wave induced by bubble injection in a fluidized bed in the whole of the bed and in the spatial intervals. Experimental results show that the attenuation of the pressure wave decreases as the diameter of bubble increases. To capture the pressure wave attenuation in the fluidized bed, it is proposed to install the pressure probe in positions approximately higher than AR times of the bubble diameter, where AR is the bubble height to width ratio. Moreover, it has been found that the attenuation in upper levels of the bed is greater than that of the lower levels of the bed. The pressure wave attenuation studies confirm that the dense phase around a bubble in the fluidized bed cannot be considered as a homogeneous phase with the same solid volume fraction.