Wyeth - Case Study
Paddle Dryer turns waste into income for food processing plant.
A northeast food processor turns its activated biological sludge waste from its manufacturing process into income by recycling the waste as an ingredient for organic fertilizer.
When the state banned landfilling of the biological waste, a study was conducted that showed the waste contained enough nutrients to be considered a fertilizer ingredient.
The company discovered the best way to produce this fertilizer ingredient was to indirectly dry the sludge to a granular state. First. a Komline-Sanderson Kompress Belt Filter Press partially dewaters the sludge to 11.5% solids. Then a steam heated K-S/Nara Model 8WL Paddle Dryer dries the belt filter press sludge cake to a granular 90% solids.
Waste water from the processing plant is aerated and clarified. Thickened sludge from the clarifier is conditioned using polymers prior to dewatering on a 2-meter wide Komline-Sanderson Kompress - Belt
Filter Press Model G-GRS (Photo 1 background).
The partially dewatered sludge enters the paddle dryer background/
Photo 2, left) through a choke screw conveyor at a rate of 2800 pounds per hour. The choke screw is used to minimize air infiltration.
The dryer consists of an omega-shaped trough with two agitators. Hollow, heated, wedge-shaped blades are mounted on the agitator's hollow shafts, This configuration provides a very high ratio of heat transfer surface area to process volume. The heat transfer surface area in this particular application is 553.1 square feet.