The press design is based on the principle of volumetric pressing due to an axial screw with a variable pitch rotating inside the screen-limited space. An additional pressing force creates resistance to the compacted waste when moving it through a discharge pipe with a variable cross-section. A correct combination of the variable pitch and variable cross section of the discharge pipe makes it possible to lift the compacted and washed from the organics sludge not only into the container, but also transport it to a height of up to 5 meters at an angle of up to 45°.

The design of the EPVP press allows its operation both separately and together with the EVK conveyor. Photos on the left show examples of the joint operation of a EPVP press with an EVK conveyor, and one example shows transportation of the dehydrated sludge to a height of four meters at an angle of 45°.

Screw wash press EPVP design

1 –  variable pitch axle screw; 2 – intake opening; 3 – hopper (for EPVP separate operation); 4 – sludge washing nozzle; 5 – sieve; 6 – drive; 7 – pressure chamber; 8 – discharge pipe; 9 – sieve washing nozzles; 10 – sump; 11 – sump washing nozzle; 12 – drain pipe.

The sludge is fed into the press through the intake opening. The axial screw moves with constant pitch in the feeding zone and with variable pitch in the compaction zone. The screw is driven by a drive. When the sludge enters the press, the screw moves it from the feeding zone to the compaction zone, where the sludge is compressed between the screw turns due to its variable pitch.

The compaction zone is limited by the sieve – the waste remains inside the sieve, and the technical and squeezed water enters the sump through a sieve.

Automatic washing system performs washing of waste and periodic washing of the outer surface of the sieve and the press sump.

The compressed and washed waste is fed into the discharge pipe, and then into the collection container. A standard discharge pipe ensures direct or lateral discharge of washed and compacted sludge into a container of up to 1.7 m³ (EN 840; OST 22-1643). In case of removal of washed and compacted sludge to a given point of unloading, the discharge pipe is designed and manufactured individually according to the corresponding requirements of the Customer.

The squeezed and technical water containing organic soluble compounds from the sludge is removed from the press through the drain pipe.

The press is manufactured in three standard versions: EPVP1.150, EPVP2.200 and EPVP4.200, differing in the external diameter of the axial screw (150 and 200 mm), with 1, 2 and 4 m³/h capacity for sludge. The EPVP4.200 modification uses a reinforced screw and sieve, due to which it can be used in the case of transportation of washed and compacted sludge to a given unloading point. In addition, each modification has two versions for the length of the feed opening - 500 mm and 1000 mm. Each of the modifications is equipped with a feed hopper or a lid for the conveyor unloading pipe.

All parts of the press, staying in contact with water and sludge, are made of AISI 304 and AISI 321 stainless steel (optionally of AISI 316).

The delivery package includes a cabinet and remote control panel for the EPVP press, which ensure its operation in manual and automatic modes, as well as protection from abnormal operation modes. In automatic (periodic) mode, the press operates from a signal coming from other equipment that is part of the production line (screen, conveyor, etc.). In the case of delivery of a press with other equipment, the control system can be integrated into the general control cabinet of the equipment system.