Development of an electro-pneumatic system for pre-stratified charge emissions control (PSC)

A control system was required to modulate the flow of supplementary air to 4-cycle rich-burn gas-fueled engines. The supplementary air is used in an exhaust emission control system for three engines known as PSC. Because the flow of this air affects combustion, other engine characteristics such as startability, load-carrying ability, and engine dynamic performance are affected, and must be taken into account in the design or the supplementary air control system. An electro-pneumatic design was developed and tested to meet these requirements.