Studies on multiphase reactor experimental investigation in stirred fluidized bed

Abstract

Fluidized beds are widely used in chemical process industries, food, pharmaceutical, biotechnology and petrochemical industries. Fluidized beds offer excellent heat and mass transfer, uniform temperature distribution and are able to process materials with a wide particle size distribution. In order to enhance the quality of fluidized bed, along with aeration, mechanical stirring can be employed. Hence, an attempt was made to study the fluidization characteristics of fluidized bed with a stirrer. Hydrodynamic studies are important to understand the characteristics of stirred fluidized bed. In the present research, hydrodynamics study in two phase stirred fluidized bed was carried out using air-water system. Pressure drop is the most important factor which affects the behaviour of fluidized bed. Hence, the effects of gas velocity and stirrer speed on pressure drop and power were studied for unstirred and stirred bed conditions. Results indicate that the pressure drop and power increases with the increase in gas velocity and stirrer speed. It is evident that pressure drop and power consumption is low for the stirred bed than the unstirred bed. Estimation of fractional gas holdup is vital as it relates directly to the gas-liquid mass transfer. Therefore, gas holdup studies were carried out in two phase stirred fluidized bed using air-water system. The effects of gas velocity, liquid height and stirrer speed on fractional gas holdup and bulk density were studied in two phase stirred fluidized bed using air-water system. The results show that fractional gas holdup increases with increase in gas velocity, stirrer speed and liquid height. newline