Rotary Valves

A rotary valve is used in bulk material handling technology for discharging and metering bulk materials. The functionality and design of rotary valves are similar to those of pumps and compressors. While the fluid in pumps is liquid and in compressors gaseous, rotary valves transport bulk materials and other solids.

The rotary valve is used for the metered conveyance of bulk materials. It transports materials such as powder, granules, grain, or pellets between two areas, even with different pressure conditions.

Inside the rotary valve, a cell wheel or rotor rotates with several chambers – called cells or chambers. These collect the bulk material at the inlet and convey it to the outlet. The gap between the rotary valve and the housing ensures that the system remains pressure-tight to a certain degree, which is especially crucial for pneumatic conveying.

Yes, there are many variants. Depending on the application and demands, a distinction is made between standard rotary valves, blow-through valves for pneumatic conveying, rotary valves, and tangential valves.

Rotary valves are nowadays frequently used as protective systems in many potentially explosive atmospheres under the EU Directive 2014/34/EU.

In general, the directive distinguishes between devices that are designed to be free of ignition sources or pressure shock-resistant and autonomous protective systems.

Autonomous protective systems are flameproof and serve for explosion isolation or as safety devices for burn-back protection. These are very often also referred to as flameproof devices.

The correct design of a rotary valve depends on factors such as flow rate, material and material properties, type of bulk material, ambient temperature, pressure conditions, installation location, and environmental conditions. Hygiene requirements or the use of rotary valves in ATEX areas also play an important role. A customized design ensures optimal function and a long service life of the system.