Known by various names, such as rotary valves or rotary airlock feeders, rotary feeders come in diverse configurations. Rotary feeder design can vary significantly depending on the application, though all have the same basic components. Applications for rotary feeders typically reply on the device providing a consistent flow of bulk materials from one process or storage container to another.

Understanding Rotary Feeder Design & Applications 

rotary_airlock_valve_rails_resizedforwebRotary feeders are industrial valves comprised of a shaft, shaft seals, end plates, electric motor, and bearings, all surrounded by a housing to protect these components. Whether a valve is considered a rotary feeder or airlock depends on its purpose. Those tasked with controlling pressure differentials between processes are known as rotary airlocks. Rotary feeders, on the other hand, control product flow either between processes or from storage containers. Sometimes these valves are used as both rotary feeders and airlocks. Besides these two primary functions, rotary feeders can act to moderate or avert explosions and fire during processing.

Rotary Feeder Design & How It Works

Regardless of their purpose, every rotary feeder has the same basic components. The rotor comes with vanes that mounted on its shaft, rotating within a cylindrical housing with an endplate attached capping each end. An inlet on the top of the cylindrical housing, allows material into the rotary feeder, while an outlet on the bottom allows material to exit.

As they spin, the vanes gather material flowing through the inlet.  

The full vanes convey material through the housing, where material flows from the pockets through the discharge. Empty vanes return to the inlet to begin the process again. The vanes and pockets turn continuously, moving material with each rotation.

Applications for Rotary Feeders

Rotary feeders are largely used to transfer bulk materials. Whether used as a rotary feeder or airlock, or both, these devices are used in industries that include agriculture, chemical processing, food processing, mining, plastics manufacturing, and power generation.

Industrial applications for rotary feeders include: 

  • Agriculture: Processing raw agricultural products like almonds, barley, beans, bran, chickpeas, dried fruit, hazelnuts, lentils, oats, peanuts, rice, rye, sesame seeds, soybeans, sunflower seeds, and wheat often requires a rotary feeder. Designed mainly to handle granulated bulk solids, these rotary feeders are normally made from carbon steel or cast iron.  
  • Chemical processing: Rotary valve design for this industry normally relies on rotary feeders functioning as airlocks to prevent contamination. Typically constructed from corrosion-resistant material, rotary feeders for this sector are used for processing chemicals like calcium carbonate, calcium sulfate, copper sulphate, sodium bicarbonate, sodium chloride and zinc chloride.
  • Food processing: Food-grade rotary feeder designs often include stainless steel to make them more hygienic. Rotary feeders are commonly used for producing coffee powder, corn flour, cornstarch, milk powder, sugar, and other dry bulk food items.  
  • Mining: Limestone, quartz, sand, and other raw minerals undergo grinding before being fed through a rotary valve. Designs must be robust, with abrasion-resistant materials often used in their construction.
  • Plastics manufacturing: Processing granulated, pelleted or powdered raw plastics like ABS, PP and PVC requires a rotary feeder. Designs generally focus on preventing material from jamming or shearing, with precision engineered parts that ensure reliable performance.
  • Power generation: Electrical power generation often requires these devices for coal used to power steam turbines. Rotary feeder designs for this application deal with a coal byproduct known as fly ash, which these devices help transfer into baghouse filters and electrostatic precipitator systems into silos or other bulk storage containers.

When used for bulk material handling, rotary feeders are integral parts of these systems.

Rotary Feeders from Prater Industries

Prater Industries makes rotary feeders for multiple applications. For rotary feeders and other equipment, we can also tailor to your needs.  

Prater rotary feeder designs include: 

To learn more about our rotary feeders, contact Prater today.