Experimental study on filtration performance of a sliding granular bed filter

Abstract

A new sliding granular bed filter (SGBF), coupling the features of fixed and moving granular bed filters, was presented. An inclined granular bed was used and filter grains slid down along the inclined bed in SGBF. The grains slid fastest at bed surface and are slowed down along bed depth. According to the movement of grains, SGBF is classified as partial SGBF (P-SGBF) and whole SGBF (W-SGBF). Our results showed that P-SGBF exhibited a similar pressure drop with W-SGBF, whereas its collection efficiency was close to that of the fixed bed. The filter quality factor was adopted to estimate the performance of SGBF by coupling the effects of collection efficiency and pressure drop. P-SGBF was superior to W-SGBF and fixed granular bed filters with increasing filtration time. In addition, effects on the performance of SGBF including granular flow rate, gas velocity and inlet dust concentration were further discussed.