Screw Conveyor Component / Bearing Series

Component Series

The recommended component series for bulk materials are listed in the Bulk Material Table. The alphabetical series codes refer to the minimum construction requirements for a screw conveyor used to convey a specific bulk material. Series A and B construction can be used for most light, nonabrasive and free-flowing bulk materials. Series C and D construction are recommended for dense, abrasive and sluggish bulk materials. Please consult KWS Engineering for further assistance.

Series A

Light Duty Construction – Series A bulk materials such as barley, cocoa beans, fish meal and sawdust are light, non-abrasive and very free-flowing. Light duty construction is very cost-effective and consists of the thinnest gauge materials available for screws, troughs and covers. Helicoid screws and angle flange troughs are recommended for Series A bulk materials.

Series B

Medium Duty Construction – Series B bulk materials such as alfalfa pellets, dry bagasse, activated carbon and crushed ice are slightly higher in bulk density, have some abrasiveness and are slightly less free-flowing when compared to Series A bulk materials. Medium duty construction is cost-effective and consists of slightly heavier gauge materials for screws, troughs and covers. Helicoid screws and angle flange troughs are recommended for Series B bulk materials.

Series C

Heavy Duty Construction – Series C bulk materials such as alumina fines, spent distiller’s grain, foundry sand and sodium sulphate are dense, abrasive and sluggish when compared to Series A and B bulk materials. Heavy duty construction is required to prevent excessive maintenance or downtime and consists of heavy duty screws, troughs and covers. Sectional screws and formed flange troughs are recommended for Series C bulk materials.

Series D

Extra Heavy Duty Construction – Series D bulk materials such as adipic acid, blast furnace slag, cement clinker and lignite coal are very dense, extremely abrasive and very sluggish when compared to Series A, B or C bulk materials. Extra heavy duty construction is required to prevent excessive maintenance or downtime and consists of extra heavy duty screws, troughs and covers. Sectional screws with weld-on hardsurfacing and formed flange troughs are recommended for Series D bulk materials.

The recommended bearing series for bulk materials are listed in the Bulk Material Table. The numerical series codes refer to the minimum requirements for screw conveyor hanger bearings used for a specific bulk material. Series 1 and 2 bearing materials are used for most non-abrasive bulk materials. Series 3 and 4 bearing materials are recommended for abrasive and extremely abrasive bulk materials. Please consult KWS Engineering for further assistance.

Series 1

Hanger bearings manufactured from engineered plastics such as Nylatron, Plastech and UHMW as well as oil-impregnated wood and ball bearings are recommended for non-abrasive bulk materials.

Series 2

Hanger bearings manufactured from engineered plastics such as Plastech as well as composite materials such as Gatke and ball bearings are recommended for bulk materials that have some abrasiveness when compared to Series A bulk materials.

Series 3

Hanger bearings manufactured from bronze and hard iron metals are recommended for bulk materials that are abrasive when compared to Series A and B bulk materials.

Series 4

Hanger bearings manufactured from ceramic, hard iron, stellite, and hardsurfaced metals are recommended for bulk materials that are extremely abrasive when compared to Series A, B or C bulk materials.