Rotary Feeder

Rotary Feeder(also referred to as rotary airlock valve,rotary valve,star feeder or rotary lock)is an essential mechanical device in industrial bulk material handling and pneumatic conveying systems.It is primarily designed to meter,regulate,and discharge dry,free-flowing bulk solids while maintaining an airtight seal to isolate pressure or vacuum differentials between connected equipment.

Working Principle

A rotary feeder operates using a multi-vane rotor that turns inside a precision-machined cylindrical housing.

Material Intake:Bulk material(powders,granules,pellets,etc.)falls from an upper hopper or bin into the pockets created by the rotor vanes.

Sealed Transfer:As the rotor rotates,the vanes maintain a close clearance seal with the housing,preventing air or gas from passing through.

Discharge:The material is carried around the housing and released at the bottom outlet into a pneumatic line or downstream process.

This continuous rotation ensures uniform material flow while blocking air leakage,making it critical for system efficiency.

Core Components

Rotor:The central rotating part with 6–12 vanes forming material pockets;can be closed-end,open-end,or customized for abrasion resistance.

Housing:The main body(cast iron,carbon steel,or stainless steel)with inlet/outlet flanges,enclosing the rotor.

Drive Assembly:Consists of an electric motor and gear reducer to control rotor speed and torque;often paired with a VFD for precise flow control.

Seals&Bearings:End-shaft seals(packing,mechanical,or labyrinth)and bearings to prevent dust ingress and maintain an airtight barrier.

End Plates:Side covers that secure the rotor and bearings,providing structural integrity.

Key Functions

Volumetric Feeding:Delivers a consistent,adjustable flow rate of material.

Pressure Isolation:Acts as an airlock to separate high-pressure and low-pressure zones,preventing system blowback or pressure loss.

Dust Containment:Contains fine powders and dust,protecting the workplace environment and meeting safety standards.

Material Discharge:Reliably unloads materials from cyclones,dust collectors,silos,and hoppers.

Common Types

Drop-Through Rotary Feeder:Standard gravity discharge design for most dry,free-flowing materials.

Blow-Through Rotary Feeder:Optimized for pneumatic conveying,with a through-bore design to inject material directly into the air stream.

Heavy-Duty Feeder:Reinforced construction for abrasive materials(cement,sand,ore,fly ash).

Sanitary Feeder:Polished 304/316 stainless steel for food,pharmaceutical,and chemical applications requiring hygiene.

Easy-Clean Feeder:Quick-disassembly design for frequent cleaning and product changeovers.

Industrial Applications

Food&Agriculture:Grains,flour,sugar,salt,spices,coffee,cereals.

Pharmaceuticals&Chemicals:Active ingredients,pigments,resins,fertilizers,plastics.

Building Materials:Cement,lime,gypsum,sand,fly ash,minerals.

Environmental Protection:Ash and dust discharge in baghouses,cyclones,and dust collectors.

Mining&Minerals:Ore,coal,alumina,and other processed minerals.