Stainless Steel Shaftless Classifier

General Description

Customer needed a solution for conveying struvite pellets (magnesium ammonium phosphate) out of a water-based slurry. The slurry is discharged from low solids anaerobic digesters. The digesters break down organic materials in the slurry using naturally occurring microorganisms to make biogas. Biogas can then be processed to produce renewable clean energy. The slurry is fed into the inlet hopper of the classifier in a batch operation. The struvite settles to the bottom of the classifier hopper and is conveyed out by the shaftless screw conveyor. Once the water drains out it gets sent to Environmental facilities for further processing. Struvite gets conveyed and discharged into containers and used as an additive in solid organic fertilizers.

Design Parameters

KWS Advantages

Engineers from Layne Heavy Civil, Environ, and KWS worked together to design a stainless steel shaftless classifier for the application. Process and site information provided by Layne Heavy Civil and Environ combined with KWS engineering knowledge of conveying ensured that the project would be a success.

Special Features

KWS designed and manufactured a special hopper and shaftless classifier trough that was completely water and gas tight. A removable drain was used for cleanout of the trough for any excess Struvite that might have settled in the bottom. The shaftless spiral was constructed out of 304 stainless steel for corrosion resistance. A special KWS flanged drive shaft was used to attach the screw mounting plate to the flange connection of the drive shaft making it easy to remove the screw without removing the drive.