Fluidization Properties and Mixing Properties of Binary Mixtures of Quartz Sand and Coal Char in Fluidized Bed

Abstract

To study the fluidization properties and mixing properties of binary mixtures of quartz sand and coal char, the experiments were carried out in fluidized bed with an inner diameter of 50 mm. The pressure drop lines and mixing index were obtained under different operating conditions with changing the static bed height and the volume fraction of coal char. A new formula of mixing index was proposed to consider the difference of horizontal mixing behavior. The result showed that the static bed height does not make an appreciable influence to minimum fluidization velocity and fluidization status. However, the volume fraction of coal char affected the minimum fluidization velocity obviously, and the minimum fluidization velocity decreased monotonously with decreasing the volume fraction. Although the small volume fraction of coal char was good for mixing, the effect was limited by the height of bed and the mixing index becomes constant almost at 80mm static bed height when the volume fraction was less than 0.4.