Screw Conveyor

Screw conveyors are used to convey the material continuously with the help of a rotating helical screw blade (known as flights) by shear and tumbling effect inside a U shaped trough or a round tube. They are generally used for handling fines of coal, crushed material, powders, cement, chemicals etc.

The periphery of leading side of the helix is provided with hard face welding for handling abrasive material. We offer screw conveyors in standard and customized solution to address varied requirements.

DEMECH also offers water cooled screw conveyor for handling and cooling material with very high temperature. We have supplied such conveyors for temperatures upto 900ºC.

Screw conveyors have the following applications - 

  1. Cement Industry: Cement, Dry & Damp Fly Ash, Coal Mill Dust, Clinker Dust, ESP Dust, Sepax Dust, Raw Mill / Kiln Cooler Dust.
  2. Food Industry : Soya bean cake and seeds, De-oiled cakes, Solvent extraction System for Edible oil industry, Sugar (Finished Goods)
  3. Chemical Industry: Stable Bleaching Powder, Soda Ash, Pue PTA, Hydrated Lime for Paper Industry, Polyfibre Industry and Bleaching Powder Industry, Carcinogen.
  4. Power Industry: Alternative Fuel ( Rice Husk /Cow Dung)
  5. Paint Industry: Sludge
  6. Steel Industry: Sinter Dust, Iron Oxide Dust, Burnt Lime, Calcined Lime, Pellet Dust
  7. Paper Industry: Burnt Lime
  • Standard screw conveyors are made out of carbon steel or stainless steel depending on the operating conditions.
  • Sizing of screw conveyor and pitch of flight is determined with the reference to CEMA standards.
  • Intermediate hanger bearings are provided for long conveyors for the screw to maintain allowable sag in the rotating member.
  • Proper selection of angular speed for the screw conveyor is critical in order to avoid wobbling effect during operation.
  • The tough filling factor is selected according to nature of material and also with reference to CEMA standard with typically value of around 30%; however, the drive power rating is calculated based on 100% filling factor.
  • For high temperature applications, a jacketed trough and box type flights are provided with circulating cooling water through, shaft & box flights. The quantity of cooling water depends on the properties & temperature of conveying material. If required, hollow flight configuration with cooling water circulated through their internal cavity can be provided to reduce temperature of the conveyed material.