Rotary Valves

This is also commonly called rotary feeder, rotary vane feeder or an airlock feeder. The rotary valve is used to dose or feed dry powder or granular products from a storage hopper or chute into a process below. The rotary feeder is precision machined to allow minimal air leakage losses through the rotor. The two general types are a drop through and a blow through feeder.

n a drop through rotary feeder product that is stored above fills into the pockets of the rotor. When the rotor tuns and a full pocket reaches the open flanged discharge of the feeder, the material drops out under gravity and falls into the process below. A drop through type can also be used for pneumatic conveying, however, it will require a feeding tee which allows the product to fall into the air stream of the conveying system.

The other type of rotary valve, the blow through is almost only used for adding product to a pneumatic conveying system. With this feeder the pressurised air supply (from a blower or fan) is connected onto the one end of the rotary valve and the conveying line onto the other. As the rotor turns, the contents under gravity are exposed to the air stream and become suspended in the air stream.
For both cases, when used in a pneumatic conveying system the air on the underside of the rotary vane feeder has a higher pressure than that above. This pressure differential results in air leakage between the rotor and the housing.

In a quality product such as feeders from DMN Westinghouse, the tolerances are custom machined to the product’s temperature. Another source of leakage air is from the empty pockets that are filled with air at a higher pressure which escapes into the product above when it rotates up. This air can be vented out of the pockets before being released into the material inlet. The DMN rotary valves are supplied with vent holes for this purpose.

DMN Westinghouse has developed rotary valves for all types of applications and industries. For any application where internal cleaning and hygiene is required, they have quick cleaning options which allows the end plate to be removed and the rotor slides out with guides. This is particularly useful in the food and certain chemical industries where no contamination is permissible.

Diverter Valves

The range of DMN Westinghouse diverter valves are designed for splitting or even converging the material stream in a pneumatic conveying line. The diverter valves are designed for specific applications, products and industries in pneumatic conveying lines.

 Plug Diverter: Two channel design with minimal maintenance requirements. The standard valves are suitable for pressures up to 3 bar using static seals, while for pressures up to 6 bar they are supplied with inflatable seals. For abrasive products the plug diverter can be supplied with wear resistant pipes.