Flex-Wall Belt Conveyor to Transport Dewatered Biosolids Conaway WWTP in Big Rock, VA

End User or Owner

Buchanan County Public Service Authority
Oakwood, VA

Consulting Engineer

Thompson & Litton
Wise, VA

Contractor

T & B Contractors, Inc.
Bristol, TN

Plant Name and Location

Conaway WWTP
Big Rock, VA

General Description

The Buchanan County Public Service Authority (BCPSA) owns and operates a 2.0 million gallon per day (MGD) rated municipal wastewater treatment plant located in western Virginia. At the plant, aerobically digested primary and secondary sludge from a rotating biological contactor system was dewatered using a hydraulically-driven belt filter press which had been in service since the mid-1980’s. The existing press system had reached the end of its service life and a new project was developed to replace the press, the belt conveyor after the press, the polymer system, and the sludge pumps. KWS Environmental provided a flex-wall belt conveyor to transport dewatered biosolids from the press room to an outside discharge location where the sludge accumulates for transfer to load out.

Design Parameters

Product Type: Dewatered Biosolids
Material Density: 50 to 70 Lbs. per Cubic Foot
Design Capacity: 67 Cubic Feet per Hour
Duty: 5 days a week, 12 Hours per Day

Flex-Wall Belt Conveyor to Transport Dewatered Biosolids at Conaway WWTP in Big Rock, VA - KWS Manufacturing

Inlet Section of New KWS Belt Conveyor Receives Biosolids

KWS Advantages

The previous belt conveyor was unreliable and hard to maintain. An engineer from KWS visited the site to understand the application and obtain dimensions of the existing conveyor. KWS also helped the consulting engineer specify a more robust solution for the new conveyor. KWS Environmental was selected as basis of design due to the support provided to the engineer during the design process. The KWS design team utilized the existing project drawings and site measurements to ensure the new KWS belt conveyor interfaced properly with the hopper below the belt filter press. The new belt conveyor was commissioned by a member of the KWS engineering team and the startup went smoothly with only minor adjustments needed.

Special Features

KWS Environmental designed the new flex-wall belt conveyor for the working conditions at the plant. A belt with corrugated side walls and cleats was selected to contain the dewatered biosolids and prevent fall back on the inclined section. The belt conveyor design also included the use of tapered return idlers for proper belt tracking with minimal belt contact. The belt beater on the previous conveyor was motorized and had not been used in a long time because it was poorly designed. KWS provided a non-motorized belt beater to clean dewatered biosolids off the belt.

KWS Environmental made sure the new belt conveyor would perform with little or no maintenance for the life of the equipment. Idler bearings are greased for life and external bearings for the pulleys are easily accessible for maintenance. To eliminate maintenance and safety issues, the drive unit is a helical gear reducer with C-face motor.