Two chamber regenerative thermal oxidizer

A two chamber regenerative thermal oxidizer comprises an oxidizing chamber and a pair of regenerator chambers. Inlet and outlet valves control fluid flow to and from said regenerator chambers. A transition duct communicates with a contaminated fluid feed duct upstream of the regenerator inlet valves and with the oxidizing chamber of said oxidizer. Electronic control means opens and closes valves, selectively, in a prearranged sequence whereby the inlet and outlet valves in an individual regenerator are never open at the same time, thereby precluding short circuiting of the regenerative chamber, yet all of the inlet and outlet valves to the regenerative chambers are never simultaneously closed thereby to maintain the pressure of fluid flow through said regenerator chambers relatively constant.