Gas induction characteristics of hollow self-inducing impeller

Abstract

The mechanism of self induction has been investigated for the case of hollow pitched blade downflow turbines. The pressure difference between the orifice and the reactor head space results into self induction of gas. The dependence of pressure difference as well as the rates of gas induction on various parameters like impeller speed, blade angle, orifice location and the number of open orifices was investigated. Gas side and liquid side resistances were experimentally measured for blade angles of 30°, 45° and 60°. An attempt has been made to propose a predictive procedure for the rate of gas induction on the basis of pressure driving force as well as the gas and the liquid side resistances. The gas induction rates for wide range of blade angle (viz. PBTD 30°, 45° and 60°), various hole combinations (viz. 1; 1,2 and 1,2,3,4,5,6) and for submergence of S = 2T/3 and for 1,2,3,4,5,6 holes at S = T/3 submergences have been predicted with this procedure. The predictions are in good agreement with the experimental results.