Multi-disc Screw Press Dehydrator at the WWTP (Savannah, GA, USA)

In February 2017 took place the installation of a complex of mechanical sludge dewatering based on the Multi-disc Screw Press Dehydrator MDQ-403C at the WWTP (Savannah, GA, USA).

Our client is a global manufacturer of food ingredients, pharmaceuticals and food. The Company’s plants are located on six continents. Representatives of the company turned to the Esmil USA Company with the problem associated with sludge dewatering. According to the technological scheme, the stage of mechanical dewatering goes through a mix of sludges after MBBR and DAF. The Client needed to decrease the sludge volume for transportation by 10 times.

Specialists from the ESMIL Company have proposed a solution based on the Dehydrator MDQ-403(C) ESMIL, polymer feeder and Control cabinet for the complex.

The dehydrator operates in continuous mode. The initial sludge is intermittently injected from the external storage tank into the dehydrator dosing tank. The mixing tank that is located in the process tank prevents the stratification of the sludge. The sludge is then supplied by a pump to the dosing tank, and then through the calibrate overflow to the flocculant tank. Sludge excess from the dosing tank returns into the process tank through the control overflow union. The polyelectrolyte solution is supplied into the flocculant tank. The solution is mixed with initial sludge by means of a mixer to form floccules. Then the initial sludge enters into the dewatering drums and moves within the screw to the zone of filter cake discharging, as a result of the screw rotation. As it moves along the drum, the sludge is dewatered and filtrate is drained through clearances between the rings.

Under screw rotation, the movable rings move parallel to the fixed rings to provide self-cleaning of the filter pores. In addition, the external drum surface is flushed by water from nozzles of the flushing unit. The drum exit is partially overlapped by the movable plate or back pressure plate. By changing the distance between the drum exit and the divider, the counter pressure on the sludge moving inside the drum can be regulated, which influences the percentage of sludge dewatering. The dewatered sludge is fed into the receiving hopper of the transporter by gravity feed.

Startup of Dehydrator was successful. Achieved DS concentration – 20% DS