Six practical ways to handle rotary airlock valve leakage
Because of the way a rotary airlock valve is designed, it's normal for a small amount of conveying air to leak back through the airlock as it feeds bulk solid material to a pressure pneumatic conveying system. But if you don't take steps to properly vent this leakage air from your equipment, it can create several problems. This article describes six practical ways of arranging your pneumatic conveying equipment to vent airlock leakage so you can avoid these problems.
While a rotary airlock valve is the most common valve for feeding dry bulk materials into a pressure pneumatic conveying system, it isn't a perfect sealing device. In fact, air leakage (also called blow-by) is inherent to the airlock's design, and the device leaks conveying air (or other conveying gas) at a rate proportional to the pressure differential across the airlock. The pressure below the airlock is created by resistance to flow as material is transferred.