Screw Press 20

The Alfa Laval Screw Press 20 is a simple, low power solution for high-performance dewatering of flocculated sludge from municipal and industrial water and wastewater treatment. It has a dewatering capacity of 5 m3/h digested sludge or 10 m3/h waste activated sludge (WAS).

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This high-performance screw press is a user-friendly, reliable and robust piece of machinery characterized by high uptime. The moderate rotational speed results in a low power consumption, which gives a direct positive impact on operational costs.

Alfa Laval controls ensure consistent continuous operation with minimal need for supervision. Operqation with low rotational speed results in an extremely low noise level, ensuring a positive working environment, and low spare parts demand.

Applications include dewatering of municipal wastewater plant sludge (primary, secondary, mixed or digested sludge), as well as industrial bio-solids and biogas residues. The screw press provides numerous benefits to processing these waste streams by reducing sludge volume, for lower transportation and disposal costs.

Benefits - Screw Press 20

  • User-friendly, minimal supervision
  • High performance and uptime
  • Cleaning during operation
  • Low power demand and operational costs
  • Low noise level, improving work environment
  • Polymer mixing valve included
  • Simple maintenance and conveyor extraction tool

How it works

Separation takes place in an inclined drum with a wedge wire screen forming the cylinder wall, and a screw conveyor. By introducing the flocculated sludge suspension (after addition of a polymer solution) into the inlet chamber, the first section of the drum is used to drain off free water that has been released.

Gradually, the sludge suspension increases in dryness as it enters into the pressure zone of the drum. By virtue of the counter-pressure created by a restricted outlet, more free water is released from the sludge cake as it progresses towards the outlet.

The released water is drained off to the outlet underneath the drum. The wedge wire screen is kept clean by intermittent flushing from the outside of the screen, and by a material at the tip of the screw conveyor flight.