MECHANICAL FOAM BREAKING - A PHYSICAL MODEL FOR IMPACT EFFECTS WITH HIGH-SPEED ROTORS

During recent years in chemical engineering processes for instance wit h aerated stirred tanks containing surface-active components foams and their mechanical control have become very important. However, there a re still no rules for calculating mechanical foam breakers. As a contr ibution to foam control the present paper discusses the fundamentals o f foam breaking by means of foam densities and gives a physical model for the mechanisms of a mechanical foam breaker when the main breaking effect is based on impact. The mechanisms were proved by measuring pr essures in a foam breaker box. Diameters of secondary foam bubbles pro duced by foam breakers are calculated and discussed. Experimental inve stigations were made with different surfactants in aqueous solutions. The paper points out their influence on the process of foam breaking.