Screw Conveyor for Dewatered Solids

General Description

The US Environmental Protection Agency (EPA) Test and Evaluation facility in Cincinnati, OH conducts experimental research on new water and hazardous waste treatment technologies to build the scientific foundation and technical solutions needed to protect human health and public water infrastructure.

As part of an ongoing project, the EPA is processing dewatered solids from a centrifuge for a drying process. Dewatered solids are typically damp, dense, and cohesive bulk materials with variable moisture content. These materials are commonly generated from wastewater treatment, environmental remediation, drilling, mining, and other separation processes where liquids are removed from slurries or a waste stream.

Nicholson Construction specializes in geotechnical construction solutions for complex civil, industrial, and infrastructure projects and was contracted by the EPA to improve the dewatering and drying process. An angled chute below the centrifuge discharge was plugging and interrupting material flow. Nicholson Construction needed a reliable screw conveyor solution to transfer dewatered solids from the centrifuge discharge to the next step in the drying process while improving cleanability and reducing maintenance concerns.

New KWS Screw Conveyor Being Installed Under Centrifuge

Design Parameters

Product Type: Dewatered Solids
Material Density: 45-100 Lbs. per Cubic Foot
Capacity: 40 Cubic Feet per Hour
Duty: Intermittent

KWS Advantages

KWS worked with Nicholson Construction to replace the problematic angled chute with a properly designed screw conveyor engineered for controlled transfer of dewatered solids. The screw conveyor eliminated the shallow transition that was causing plugging and provided positive movement of material away from the centrifuge discharge. KWS designed the inlet area to match the centrifuge discharge and promote smooth material flow into the conveyor. Because the process operates intermittently, KWS focused on accessibility, cleanability, and dependable restart after shutdown. The custom screw conveyor provided Nicholson Construction with a reliable solution that reduced plugging, improved housekeeping, and helped maintain consistent operation of the drying process.

KWS Special Features

The new KWS screw conveyor was designed with special features to solve the material handling and cleaning challenges associated with dewatered solids. A custom inlet transition chute was fabricated to properly mate with the centrifuge discharge and direct material into the screw conveyor without creating ledges or dead spots where solids could accumulate.

A drop bottom cleanout was located directly below the inlet to provide quick access to the area most likely to collect material during intermittent operation. The cleanout allowed operators to remove buildup and inspect the inlet area without disassembling the conveyor.

The screw conveyor was also supplied with an expanded metal cover to allow water spray cleaning while maintaining a guarded cover over the rotating screw. This feature improved washdown access and helped keep the conveyor clean between operating cycles. The combination of the custom inlet transition, drop bottom cleanout, and expanded metal cover provided a practical, maintenance friendly solution for conveying dewatered solids from the centrifuge to the drying process.