Biosolids Loadout Screw Conveyor for Jessamine Creek WWTP Nicholasville, KY

General Description

The City of Nicholasville, KY is home to more than 28,000 residents and many businesses. The Jessamine Creek Wastewater Treatment Plant services the city and processes an average of 4.5 MGD with a peak of 14 MGD. The state of Kentucky has an initiative to reduce negative environmental impacts from their treatment plants. The Jessamine Creek WWTP has surpassed the goals established by the government and received numerous awards for water quality with no violations in the past 5 years.

The Jessamine Creek WWTP had an issue with biosolids spillage when loading dumpsters. The existing load out system had only one discharge point. When a dumpster became full and needed to be removed and transported to landfill, biosolids would continue to discharge from the load out conveyor causing a spillage and housekeeping issue. Engineers from KWS Environmental met with the plant supervisors to determine a feasible, cost effect solution. The resulting screw conveyor was reversible in operation with two discharge points. Dumpsters could be located under each discharge point and one dumpster filled at a time. As a dumpster became full, the screw conveyor would reverse and start filling the second dumpster. The full dumpster could then be removed and replaced with another empty dumpster.

Design Parameters

KWS Advantages

Due to the limited scope of the project and funds available, KWS Environmental was responsible for both designing and manufacturing the load out screw conveyor. Engineers from KWS worked with the operators at Jessamine Creek WWTP to define the needs of the process, determine space constraints and specify any necessary features of the screw conveyor. With over 45 years in the conveying industry, KWS Environmental helped define a load out conveyor that met the needs of the customer with minimal initial cost and low total cost of ownership.

Special Features

KWS Environmental supplied a shafted screw conveyor made from heavy duty carbon steel construction. The screw conveyor was very cost-effective and had a minimal number of components to maintain or replace. CEMA standard components such as hanger bearings and trough ends were used where ever possible. KWS designed the screw with ribbon flights in order to prevent the sticky biosolids from adhering to the flights and causing a reduction in conveying capacity.

Special mounting lugs were welded to the sides of the screw conveyor so that it could be easily hung from the ceiling joists. The plant personnel wanted to utilize the same type of mounting lugs as other equipment in the plant and provide a consistent method of supporting equipment.

The KWS shafted screw conveyor is reversible with use of a selector switch, which allows one of two dumpsters to be filled at any time. The system can run continuously as a full dumpster is replaced with an empty one.