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Process Wastewater Technologies Volute Dewatering Press

PWTech Volute Dewatering PressThe PWTech volute dewatering press is a unique product, originally developed in Japan that offers many advantages over current sludge management practices.

Process Description

Sludge is fed into a mixing tank where polymer is thoroughly mixed in. The sludge then passes through a flocculation tank where gentle mixing and flocculation occurs. From there, the sludge overflows into the dewatering drum and is pressed. The entire operation is controlled by the volute dewatering press control panel.

Operation and Maintenance

The Volute dewatering press requires very little operator attention, other than periodic inspection and chemical replenishment. As a fully automated process, it controls the operation of wasting sludge directly from the biological process or clarifier, chemical make-up and dosing, flocculation and then dewatering. Depending on operating conditions a partial overhaul of the dewatering drums may be required every three years. This two hour operation is undertaken in the field, with minimal disruption to plant operation.


  • No need for thickeners, sludge storage, or separate dosing facilities
  • No need for regular operator attendance
  • Produces high quality filtrate, does not need to return to the head works
  • Low power consumption
  • Low noise and odor generation
  • Low wash water consumption
  • Able to handle oily sludge
volute dewatering press