Hydrodynamic characteristic study of a three phase co-current trickle-bed system

Abstract

Trickle-bed has been extensively used in chemical process industries mainly in petrochemical and refinery process since it provide flexibility and simplicity of operation as well as high throughputs. The basic parameter which is used in the design, scale-up and operations of a trickle bed reactor are the pressure gradient and liquid saturation. Knowledge of these hydrodynamics parameters and prevailing flow regime is the fundamental parameters for the design and performance evaluation of the reactor. But trickle bed reactor involves complex interaction of gas and liquid phase with packed solid which is very difficult to understand. Many computational models have been developed and extensive computational fluid dynamics study of hydrodynamics parameters has been done in last few decades to understand the behaviour of trickle bed reactor. In the present study experiments have been carried out in a concurrent downflow air water trickle bed reactor to investigate the pressure drop and dynamic liquid saturation in trickle flow and pulse flow regime. In trickle flow regime it is found that dynamic liquid saturation increases with increase in liquid flow rate followed by decrease when transition to pulse flow regime begins. However, in the pulse flow regime a dip in the dynamic liquid saturation curve is found. A sudden rise in pressure drop is observed when transition from trickle to pulse flow regime occurs.