About Screw Feeders
Schwing Bioset offers four models of twin screw feeders to deliver biosolids into the piston pump. Their primary function is to feed non-flowing material into the pump to ensure high pump efficiencies are achieved. The opening length of the screw feeders come in many sizes to accommodate even the most unique Customer needs.
Each screw is supported at the drive end by oil lubricated bearing installed in the screw feeder gear box and at the tail end by outboard grease lubricated bearings. The gear box is sized in accordance with the material to be pumped and the pressure required in the suction housing to ensure good filling efficiency. The entire rotating assembly is designed to provide continuous duty under all anticipated load conditions.
Screw Feeder Features
Transition Pressure Sensor: A pressure sensor is mounted in the transition from the screw feeder to the piston pump to control the speed of the screw feeder augers. The pressure sensor is set to maintain a constant pressure in the transition regardless of pump speed or solids content of the material. As either fluctuate, the screw feeder speed responds to maintain this constant pressure. This pressure sensor maximizes pump cylinder fill efficiency and in turn maximizes the wear life of the wearing parts and minimizes power consumption.
Closed Loop Controls: Schwing Bioset offers hoppers over the twin screw feeders that include level sensors. The level sensor signal automatically controls the speed of the pump, ensuring the hopper never runs empty or overfills. Additionally, Schwing has patented the Closed Loop Controls whereby the hopper level signal also controls the extraction rate of biosolids from an upstream storage bin. This method of control allows for full automation of the Schwing Bioset supplied pump system and allows seamless integration into the plant control system.
Optional Stainless Steel: Standard screw feeder construction is carbon steel. As an option for corrosive applications the screw feeders are also available in stainless steel.
Intermeshing Augers: The counter-rotating screws are designed to be self-cleaning during operation. They also provide thorough mixing in applications where additives are being introduced into the biosolids. Mixers are also available with adjustable paddle flights.
Heavy Duty Gearboxes: SBI's Heavy Duty version offers up to 12,000Nm of torque, allowing even the driest sludge, cake, or biosolids to be fed into the pump. The Heavy Duty gear boxes allow materials previously thought to be unpumpable to be moved with ease.