Rotating airlock valves are also known as rotary feeders, rotary valves, or simply rotary airlocks. These valves, which are used in pneumatic conveying systems with both pressure and vacuum styles, work as a "lock" to stop air loss while also carrying out essential material handling tasks.
A rotary airlock feeder lets material flow through while separating a pressure differential. The best way to understand how it operates is to picture a building's rotating door—it permits material to pass through while preserving the pressure difference between the inside and outside of the structure.