What is a Screw Press Dewatering Machine?

The screw press sludge dewatering machine is a new type of solid-liquid separation device that utilizes the screw extrusion principle.It applies strong squeezing force generated by the variation in screw diameter and pitch,along with the tiny gaps between the moving and fixed rings,to achieve sludge dewatering through compression.

1.Components of the Screw Press Dewatering Machine

1)Screw Press Body
-Consists of fixed rings,moving rings,a spiral shaft,bolts,spacers,and connecting plates.
-The fixed rings are connected by six bolts,with spacers and moving rings placed between them.Both fixed and moving rings are made of wear-resistant materials to ensure long service life.
-The spiral shaft runs through the center of the fixed and moving rings,with the moving rings loosely fitted around it.

2)Spiral Shaft
-Composed of a shaft and spiral blades.The shaft is welded from a solid shaft and a hollow shaft.
-During assembly,the solid and hollow shafts are welded first,then rough-turned to ensure coaxiality.The spiral blades are then fully welded to the shaft.

3)Drive Unit
-Serves as the power source of the machine,directly affecting overall performance.
-High-performance motors are typically used,with a protection rating of IP54 and insulation class F.

4)Filtrate Tank
-A welded structure used to collect filtrate discharged during dewatering.
-Mounted to the frame with screws and equipped with flanges for external connections.

5)Mixing System
-Ensures thorough mixing of sludge and flocculant to form flocs before entering the dewatering section.

2.Working Principle of the Screw Press

After preliminary gravity thickening in the concentration zone,the sludge is transported to the dewatering zone.As it moves forward,the decreasing gap between rings and pitch of the spiral shaft,combined with the resistance from the back-pressure plate,generates high internal pressure,continuously reducing volume and achieving efficient dewatering.

1)Concentration
-As the spiral shaft rotates,multiple stacked rings move relative to each other,allowing water to filter out through the gaps under gravity,achieving rapid concentration.
2)Dewatering
-The concentrated sludge advances with the spiral shaft’s rotation.
-Toward the outlet,the pitch and gaps between rings gradually decrease,compressing the sludge.
-The back-pressure plate increases internal pressure,forcing water out and producing a high-solid-content sludge cake.
3)Self-Cleaning Mechanism
-The rotation of the spiral shaft drives the moving rings,creating continuous relative motion between fixed and moving rings to prevent clogging.

3.Operation Procedure

-Startup:Activate the spray system 10 minutes before feeding sludge.Excess sludge flows back through the overflow port.
-Process:Sludge mixes with flocculant in the mixing tank to form flocs,then enters the dewatering section.Water drains through ring gaps,while the sludge is compressed and discharged as a dry cake.
-Shutdown:Run the spray system 30 minutes before stopping to clean residual sludge from the shaft and rings.
3.Advantages
-Automation:Fully automated operation reduces labor costs.
-High Efficiency:Continuous processing with large capacity and high dewatering rate.
-Anti-Clogging:Self-cleaning design ensures stable long-term operation.
-Durability:Wear-resistant materials extend equipment lifespan.