1 School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran

2 Department of Mechanical Engineering, Hacettepe University, Ankara, Turkey

3 Department of Chemical Engineering, Middle East Technical University, Ankara, Turkey

4 University of Tehran



Attrition of 300 µm natural zeolite particles was studied in a laboratory scale draft tube spouted bed (DTSB) and spout-fluid bed (DTSFB). It was shown that the attrition rate decreases with time and reaches to an almost constant value. The results showed that the prevailing attrition mechanism in the consitions of this work is surface abrasion which occurs due to collisions of particles. It was found that increasing the cone angle from 30º to 60º in the DTSB, causes decrease in extent of attrition. In addition, with increasing the spouting air velocity and height of the entrainment zone in DTSB, the extent of attrition increases due to more energetic collision of particles as well as increased circulation rate of solids. Increasing the auxiliary air velocity in the DTSFB increases the rate of attrition. A comparison between attrition in DTSB and DTSFB was conducted which indicated that applying the auxiliary air flow causes up to 6% increase in the extent of attrition. An empirical correlation is derived for evaluating the extent of attrition in DTSB and DTSFB. This empirical correlation is in a good agreement with the experimental data.