Rotary Airlocks usually serve as part of a pneumatic conveying system. On the input side, vanes inside the airlock spin and receive bulk raw materials while discharging air from the pressurized side of the system. As they spin around, they then discharge the bulk raw materials into the conveying system with a minimum of air pressure lost.
Electro-Sensors' Speed Switches are used on Rotary Airlocks to monitor critical speed, and guard against slowdown or stoppage that can result in costly process downtime, machine damage, and material waste. Speed Switch Tutorial.
Ratemeters and Tachometers are commonly used in this type of application to display the RPM of the conveyor.