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.

Technical Details
  • 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 application 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.
Demech refer CEMA standards for sizing, power calculation and construction of screw feeders / conveyors.
  • Screw feeders are supplied with variable pitch.
  • Standard screw flights are continuous, however, variation in Screw conveyor flights can be provided depending upon the properties of the Material to be handled – e.g. Cut Flight; Cut & Folded Flight & Ribbon Flight.

Demech has supplied conveyors of trough diameters of 150 to 800 mm, length from 3 meters to 50 meters and material handling capacities varying from 0.6 TPH to 100 TPH.

Water cooled screw conveyors supplied by Demech are handling Material having temperatures upto 900°C. Such conveyors are manufactured from special high temperature Stainless steel.

Applications area
  • Cement Industry - Cement, Dry & Damp Fly Ash, Coal Mill Dust, Clinker Dust, ESP Dust, Sepax Dust, Raw Mill / Kiln Cooler Dust.
  • Food Industry - Soya bean cake and seeds, De-oiled cakes, Solvent extraction System for Edible oil industry, Sugar (Finished Goods)
  • Chemical Industry - Stable Bleaching Powder, Soda Ash, Pue PTA, Hydrated Lime for Paper Industry, Polyfibre Industry and Bleaching Powder Industry, Carcinogen.
  • Power Industry - Alternative Fuel ( Rice Husk /Cow Dung)
  • Paint Industry - Sludge
  • Steel Industry - Sinter Dust ; Iron Oxide Dust ; Burnt Lime , Calcined Lime, Pellet Dust
  • Paper Industry - Burnt Lime
Salient Features
Trough Conveyor
  • These conveyors are fabricated in Mild Steel and / or Stainless Steel material.
  • The conveyors are dust sealed with felt, 'O' rings or oil seals.
  • Designed for Pressure and vapor-tight requirements.
  • Hard facing on carrying side of flight with 350-400 BHN hardness

Water Cooled Screw Conveyors
  • DEMECH has manufactured and supplied Water Cooled Screw conveyors for material with temperature up to 9000C to handle
    • - Clinker Dust
    • - Coal & Sludge Bottom Ash
    • - Bed Ash
  • Such conveyors are provided by circulating cooled water through jacket around trough and the central shaft.
  • If required, hollow flight configuration with cooling water circulated through their internal cavity are provided to reduce temperature of the conveyed material.
Clients Served
1. Humbold Wedag, New Delhi, Project:Raysut, Oman
2. Thermax Limited, Chinchwad, BILT-Sabah Forest Industries, Malaysia
3. Outotech India Pvt.Ltd, Project: Ilmenite Smelting Plant , Dubai
4. Madras Cements Ltd., Chennai, Project: Jayanthipuram
5. Jaypee Rewa Plant (A Unit of Jaiprakash Associates Ltd.)
6. Murli Industries Limited Cement Unit, Chandrapur
7. ACC Limited, Thane, Project: ACC- Bargarh
8. Prism Cement - Unit II, Satna (M.P.)
9. Megha Technical & Engineers Pvt. Ltd. (Cement Project)
10. ETS-ELEX (India) Pvt.Ltd, Thane, Project: Humboldt Wedag
11. Proj: Humboldt Wedag (P)Ltd, New Delhi, Proj: Lafarge Ashaka Lignite
12. Sabhash Engg Pvt.Ltd, Chennai, (Cement Project)
13. Ballarpur Industries Ltd, Mehrauli, Gurgaon road, Haryana
14. Bihar Caustic & Chemicals, Garhwa Road, Rehla, Jharkhand
15. Tata Iron & Steel, Jamshedpur
16. JSW Steel Ltd., Vijaynagar , Karnataka
17. Visa Steel Limited, Kalinganagar, Jakhapura
18. SMS India Pvt.Ltd, New Delhi, Project: Visakhapatnam Steel Plant
19. Thermax Ltd, Enviro Division, Project: JSPL
20. Greenesol Power Systems, Bangalore (Power Sector)
21. Veesons Energy Systems Pvt.Ltd., Trichy