Screw Conveyor Engineering Guide
Standard Pitch, Single Flight
Conveyor screws with pitch equal to screw diameter are considered standard. They are suitable for a wide range of materials in most conventional applications.
Short Pitch, Single Flight
Flight pitch is reduced to 2/3 diameter. Recommended for inclined or vertical applications. Used in screw feeders. Shorter pitch retards flushing of materials which fluidize.
Half Pitch, Single Flight
Similar to short pitch, except pitch is reduced to 1/2 standard pitch. Useful for vertical or inclined applications, for screw feeders and for handling extremely fluid materials.
Long Pitch, Single Flight
Pitch is equal to l½ diameters. Useful for agitating fluid materials or for rapid movement of very free-flowing materials.
Variable Pitch, Single Flight
Flights have increasing pitch and are used in screw feeders to provide uniform withdrawal of fine, free-flowing materials over the full length of the inlet opening.
Double Flight, Standard Pitch
Double flight, standard pitch screws provide smooth, regular material flow and uniform movement of certain types of materials.
Tapered, Standard Pitch, Single Flight
Screw flights increase from 2/3 to full diameter. Used in screw feeders to provide uniform withdrawal of lumpy materials. Generally equivalent to and more economical than variable pitch.
Single Cut-Flight, Standard Pitch
Screws are notched at regular intervals at outer edge. Affords mixing action and agitation of material in transit. Useful for moving materials which tend to pack.
Cut & Folded Flight, Standard Pitch
Folded flight segments lift and spill the material. Partially retarded flow provides thorough mixing action. Excellent for heating, cooling or aerating light substances.
Single Flight Ribbon
Excellent for conveying sticky or viscous materials. Open space between flighting and pipe eliminates collection and buildup of the material.
Standard Pitch With Paddles
Adjustable paddles positioned between screw flights oppose flow to provide gentle but thorough mixing action.
Adjustable paddles provide complete mixing action, and controlled material flow.