Shaftless Screw Conveyor for Johnson County WWTF

General Description

The Jonhson County Wastewater Treatment Facility (WWTF) is in the city of Smithfield, North Carolina and has a nominal capacity of 10 million gallons per day (MGD). The new treatment facility is to replace the existing facility that has been shut down numerous times by flooding from hurricanes by being located adjacent to the Neuse River. The new facility will be located away from the river to prevent potential flooding from shutting down the facility. The new facility required a new KWS Environmental shaftless screw conveyor to transfer screenings from a bar screen to a compactor.

Design Parameters

1. Product Type: Screenings
2. Material Density: 45 Lbs. per Cubic Foot
3. Max Capacity: 150 Cubic Feet per Hour
4. Duty: 24 hours a day, 7 days a week

KWS Advantages

KWS Environmental was selected as the screw conveyor supplier based on engineering capabilities, prior project successes and overall equipment quality. KWS engineers worked with the contractor and engineer to successfully coordinate the design and location of conveyor supports.

KWS has over 1,000 successful installations with proper interface to screens, compactors, and other process equipment. The equipment shipped ahead of schedule and installed cleanly. A degreed mechanical engineer from KWS provided a customized startup procedure, O&M manuals, and on-site training to ensure the equipment was put into service correctly.

KWS Special Features

For conveying and elevating wet screenings, KWS chose a shaftless screw conveyor. The lower end of the conveyor had a drain so that excess liquids could be removed from the process. Made from high-strength Microalloy, KWS shaftless spirals are the strongest and toughest in the industry. The KWS one-piece flanged drive shaft is guaranteed for the life of the equipment.

To prevent corrosion, the conveyor trough and covers were made of 304 stainless steel. KWS engineered a custom inlet chute to connect to the screen outlet and transition to the conveyor. In order to stop the conveyor when there is a loss of screw rotation, a zero-speed switch was included. KWS also included an emergency stop switch that will instantly halt the conveyor in the event that an unfavorable operating situation is detected. The emergency stop and zero-speed switches both contribute to the safety of plant workers and to protect the conveyor and upstream and downstream equipment from damage.