Screw Conveyors are equipment for movement of free flowing Bulk, Powder or Granular material by Rotating Helical Screw Blades within a tubular chamber. They may be Horizontal or slight Inclined. Relative low capital cost , running cost , its simple & dust free operation ,ability to handle a wide range of granulated & powdered materials, makes it a popular material handling & conveying equipment . The rate at which material is conveyed can be fairly contolled by varying the screw flight design , speed and percentage loading .
Helical /Spiral Blades (flights) continuously welded to a central shaft, free on one end - driven at the other ,forms the basic construction of this equipment . Pitch sizing depends on its function. The entire length of the Screw Conveyor length may be made up of numbers of screws , in lengths varying from 2-3 meters , supported Intermediate Hanger bearings made up of fabricated / cast bodies , self lubricating bushes , coupled by Splined coupling shafts. . The two extreme ends of shaft rest End bearings comprising of CI-Body Plummer block, bearings , Shaft seals ,splined coupling shafts on robust cast iron bearings .
The tubular chamber ( Troughs) are designed and manufactured in modular lengths of 2 to 3 meters , providing flexibility of extending or shortening the length of the Conveyor and also facilitates easy assembly , installation & maintenance . The drive arrangement installed on a sturdy platform coupled to shaft screw could be fixed/ variable , chain / belt driven .
The conveyors may be directly bolted to equipment like Main Bag filter ( MBF ) or suitable quick openable Dust tight and weather proof, top covers to which square/ round inlet openings / nozzles are welded . Outlet openings are provided at trough bottom.
Typical Screw Conveyors are Designed & Manufactured as per standards Conveyor Equipment Manufacturers Association ( CEMA) , A N S I 3 0 0 -1 9 8 1, IS – 5563