Controlling Pulsed Incompressible Flow

Abstract

Unit operations continue to be evolved for the production of fuel from waste. One such device, the active pulsed‐flow air classifier, called for the design of a valve to pulse the airflow. This valve had to be capable of pulsing airflow at frequencies ranging from 0.5–5 Hz; approximating a sawtooth waveform; inducing and varying pulse asymmetry; working in incompressible flow; handling large flow volumes; posing minimal obstruction to the airflow when fully open; closing to varying degrees; and consuming a minimum of power. This work discusses the development of testing of three configurations. Design of the valve elements most affected by special operational requirements is discussed. Techniques of analysis are presented. The louvered valve is identified as the best valve; its design equations are developed. The best control system was electropneumatic. It was geographically impossible to combine the two, although they are forecast to make up the best system.