Screw Conveyor for the city of Yelm, WA

General Description

Yelm is a rapidly growing city in southeastern Thurston County, WA and recognized as the historic “Gateway to Mount Ranier”. The installation of a Bioforcetech (BFT) biodryer and septage receiving station represents the next phase in the city’s comprehensive modernization of its water reclamation facility. This innovative technology supports the city’s commitment to sustainability while enhancing operational efficiency and long-term resource management. The addition of the biodryer provides the capability to process its own septage and waste activated sludge onsite, eliminating the need to transport material to an offsite facility at an annual cost of over \$300,000.00.

The City of Yelm selected KWS to provide the additional screw conveyors required for the biodryer system expansion, leveraging KWS’s extensive experience and the seamless integration of the new equipment with the existing KWS conveyors already in service at the facility.

KWS Shaftless Screw Conveyors Transfer Biosolids to Bioforcetech (BFT) Dryer

Design Parameters

Product Type: Biosolids or Sludge
Material Density: 65 Lbs. per Cubic Foot
Capacity: 307 Cubic Feet per Hour
Design Temperature: Ambient
Duty: Intermittent

KWS Advantages

KWS engineering personnel worked closely with Parametrix, the consulting engineering firm supporting the City of Yelm, to ensure the new KWS screw conveyors would seamlessly receive material from the existing process equipment. KWS developed detailed three-dimensional models of the screw conveyors for integration into the overall facility model, allowing for layout verification and coordination. Following installation, a KWS field service representative conducted comprehensive equipment commissioning and operator training, ensuring successful system integration and a smooth startup of the conveying system.

KWS Special Features

To enhance safety and protect equipment, the screw conveyors feature a cable-actuated emergency stop system and a speed monitoring sensor. The emergency stop system allows operators to immediately halt conveyor operation through an externally mounted cable that runs the conveyor’s perimeter and connects to a central control unit. The speed monitoring sensor detects when the conveyor spiral is not moving and sends a signal to upstream control panels, triggering an automatic shutdown of connected machinery in the event of a sudden jam or mechanical failure. Together, these safety features provide comprehensive protection for both personnel and equipment.

KWS shaftless screw conveyors are designed for exceptional durability and dependable long-term performance in demanding operating environments. Each conveyor is equipped with heavy-duty ultra-high molecular weight (UHMW) polyethylene liners that provide outstanding resistance to wear and abrasion, helping to maximize equipment life and minimize maintenance requirements. To ensure long-term corrosion resistance and structural integrity, all external components—including the conveyor troughs, inlet chutes, and support structures—are fabricated from 304 stainless steel.

Customer Testimonial

“The KWS screw conveyors are operating perfectly with no issues. Installation went smoothly and easily. Thanks for the onsite assistance and training!”

Brian E. Bunker, Senior Consultant – Parametrix