Dynamic granular bed and its gas–solid separation process

Abstract

In this work, a new concept of dynamic granular bed was proposed based on the inertial number theory of powder mechanics. Compared with conventional moving granular bed, a fast-moving granular layer was formed on dynamic granular bed, which can capture the dust particulates and transport them away rapidly. The dust cake can be kept at a certain amount of thickness even after long-term operation. Hence the blowback process is not required in dynamic granular bed. Periodic working moving granular bed is then changed to continuous and steady working dynamic granular bed. Two kinds of dynamic granular beds were numerically and experimentally investigated in this work, i.e., vertical and inclined dynamic granular bed. It is found that inclined dynamic granular bed is superior to vertical dynamic granular bed. The experimental results show that there exist optimal parameters of both filtration superficial velocity and mass flow rate of filter granules for dynamic granular bed. Specifically the best collection efficiency occurred at a filtration superficial velocity of 0.3m/s and a mass flow rate of 300g/min for both vertical and inclined dynamic granular bed in the experiments.