I. Sludge dehydrator introduction
Screw press sludge dewatering machine is an efficient and reliable solution to sludge water management and wastewater treatment. It utilizes a screw mechanism to transport and compress sludge, separating the water from the solid materials. The dewatered sludge cake is with reduced moisture content and volume, making it easier to handle and dispose of.
It adopts the screw extrusion principle. The rotation of the screw shaft produces a great internal pressure under the blocking action of the backpressure plate while pushing the sludge transportation so that the volume is continuously reduced, and the purpose of dewatering is finally achieved.
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II. Sludge dehydrator description
DAGYEE's Sludge Dewatering Screw Press Machines are known for their robust design and exceptional performance, making them a trusted choice for applications in municipal wastewater treatment plants, industrial facilities, and more. With a commitment to sustainability and eco-friendliness, our machines contribute to cleaner and greener water management practices, enhancing operational efficiency while meeting stringent environmental regulations. Choose RPE for cutting-edge solutions that set new benchmarks in sludge dewatering technology, ensuring a cleaner and more sustainable future.

III. Sludge dehydrator process
The dehydrator is mainly composed of sludge premix module, concentration and dewatering module and electric control system. In the actual working process, the sludge is pumped to the metering tank by an external conveying pump. The sludge after distillation further flows into the flocculation tank, reacts with the flocculant fully under the stirring of the agitator to produce stable alum, and then enters the dewatering screw through the upper part of the flocculation tank. In the dehydrated body, alum flowers concentrate in the concentrated section by gravity and advance to the dehydrated section at the same time. In the process of propulsion, with the filter clearance and pitch gradually reduced, and the back pressure plate blocking effect.
The main body of the screw press dehydrator is a filter device which is superimposed by a plurality of fixed rings and floating rings, and the screw shaft runs through it. The anterior segment is concentrated and the posterior segment is dehydrated. Sludge concentration and dewatering are done in one cylinder. During the spiral rotation, the floating ring and the fixed ring will form a dislocation movement, and the water will be discharged from the gap between the floating ring and the fixed ring. It replaces the traditional filter cloth filtering method with a unique and subtle filter pattern.
Following the principles of force and water in the same direction, thin layer dehydration, appropriate pressure, and prolonged dehydration path, the screw press solves the problems of easy blockage, inability to handle low-concentration sludge and oily sludge, high energy consumption, and complex operation. The dehydration goal of high efficiency and energy saving was achieved.

IV. Sludge dehydrator overall composition
The dehydrator is mainly composed of sludge premix module, concentration and dewatering module and electric control system.

The main body of the screw press dehydrator is a filter device which is superimposed by a plurality of fixed rings and floating rings, and the screw shaft runs through it. The anterior segment is concentrated and the posterior segment is dehydrated. Sludge concentration and dewatering are done in one cylinder.
The screw press, with conical screw shaft and cylindrical screen, consists of three treatment zones: an inlet and drive zone, a three-part thickening and dewatering zone and a press zone with a pneumatic counterpressure cone. Cost-effective sludge dewatering with independent sludge treatment.
In the first part of the thickening and dewatering zone, the supernatant is quickly removed by a feed pump through a large free filter surface at low primary pressure. A pressure probe in the feed zone controls the primary pressure, thus ensuring consistent filtrate quality.
In the second part of the screen, the volume of material between the screw threads is reduced by means of a conical screw and the sludge is pressed against the inner surface of the screen, thus dewatering the sludge and decreasing the cake thickness. The screen aperture in this screen section is much smaller.
In the third part of the screen, the remaining water is pressed out of the sludge with minimum cake thickness by a pneumatic counterpressure cone at the press-out. The dewatered sludge is pushed by a screw conveyor over the pressure cone into the discharge chamber. The residence time of the sludge in the screw press as well as the filtering time can be adjusted by adjusting the speed of the screw shaft to meet individual requirements.
The initial section of dewatering drum is the thickening Zone, where the solid-liquid separating process takes place and where the filtrate will also be discharged. The pitch of the screw and the gap between the rings decrease at the end of dewatering drum, hence increasing its internal pressure, end Plate further increases the pressure, so as to discharge dry sludge cake.

V. Sludge dehydrator complete practical operation steps
The operation of a Multi-disc Screw Press follows these basic steps:
Sludge Conditioning
Polymer is mixed with the incoming sludge to agglomerate the solid particles, forming larger flocs. This increases filtration efficiency.
Sludge Feeding
The conditioned sludge is fed into the dewatering drum.
Thickening and Dewatering
The drum consists of a screw shaft that rotates slowly. Surrounding this screw are alternating fixed and moving rings. As the screw rotates, it transports the sludge toward the outlet. During this movement: Water is drained through the narrow gaps between the discs. Pressure increases as the pitch of the screw tightens and the volume decreases, squeezing more water out of the sludge.
Cake Discharge
The dewatered sludge (now a semi-solid cake) is pushed out from the end of the screw shaft for disposal or reuse.
Sludge is first flow into the Control Tank and then flows down into the Flocculation Tank, Where polymer coagulant is added. From there, the flocculated sludge overflows into the dewatering drum where it is filtered and compressed. The entire operation sequence, including sludge feed control, polymer makeup, dosing and sludge cake discharge are controlled by the built-in timer and sensors of the PLC.
The sludge is delivered to the metering tank through the sludge pump, and then the sludge flows into the flocculation mixing tank. The excess sludge flows back to the sludge tank from the overflow pipe. Inject polymer flocculants into the flocculation mixing tank, alum floc formed after stirring, and then enters into a dewatering section of a screw press after gravity concentration (pre-treatment) section. Flocculation and dewatering are carried out in sequence, so that we have a three-stage separation process: flocculation, dewatering and concentrate recovery.
The sludge enters the dewatering machine and the sludge moves towards the sludge cake outlet under pressure from the helical screw blades. Since the pitch becomes narrower towards the outlet of the sludge cake, the sludge bears heavier pressure and begins to dewater. Water comes out from the space between fixed and moving rings while dry solids exits from the outlet.
In the actual working process, the sludge is pumped to the metering tank by an external conveying pump. The sludge after distribution further flows into the flocculation tank, reacts with the flocculant fully under the stirring of the agitator to produce stable alum flocs, and then enters the dewatering screw through the upper part of the flocculation tank. In the dehydrated body, alum flowers concentrate in the concentrated section by gravity and advance to the dehydrated section at the same time. In the process of propulsion, with the filter clearance and pitch gradually reduced, and the back pressure plate blocking effect. During the spiral rotation, the floating ring and the fixed ring will form a dislocation movement, and the water will be discharged from the gap between the floating ring and the fixed ring. It replaces the traditional filter cloth filtering method with a unique and subtle filter pattern.

VI. Sludge dehydrator model
| Model | DS Capacity (kg/h) Min | DS Capacity (kg/h) Max | 2g/L | 5g/L | 2g/L (m³/h) | 5g/L (m³/h) | 10g/L | 20g/L | 25g/L | 50g/L | Spiral Diameter | Discharge Distance |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| DL101 | 3 | 5 | 1.5 | 0.6 | 1.5 | 0.6 | 0.5 | 0.25 | 0.2 | 0.1 | Φ100×1 | 215 |
| DL131 | 6 | 10 | 3 | 1.2 | 3 | 1.2 | 1 | 0.8 | 0.4 | 0.2 | Φ130×1 | 260 |
| DL132 | 12 | 20 | 6 | 2.4 | 6 | 2.4 | 2 | 1 | 0.8 | 0.4 | Φ130×2 | 250 |
| DL202 | 18 | 30 | 9 | 3.6 | 9 | 3.6 | 3 | 1.5 | 1.2 | 0.6 | Φ200×2 | 350 |
| DL301 | 30 | 50 | 15 | 6 | 15 | 6 | 5 | 2.5 | 2 | 1 | Φ310×1 | 495 |
| DL302 | 60 | 100 | 30 | 12 | 30 | 12 | 10 | 5 | 4 | 2 | Φ310×2 | 495 |
| DL303 | 90 | 150 | 45 | 18 | 45 | 18 | 15 | 7.5 | 6 | 3 | Φ310×2 | 495 |
| DL352 | 120 | 200 | 60 | 24 | 60 | 24 | 20 | 10 | 8 | 4 | Φ350×2 | 580 |
| DL353 | 180 | 300 | 60 | 36 | 60 | 36 | 30 | 15 | 12 | 6 | Φ350×3 | 580 |
| DL402 | 120 | 200 | 60 | 24 | 60 | 24 | 20 | 10 | 8 | 4 | Φ410×2 | 585 |
| DL403 | 180 | 300 | 60 | 36 | 60 | 36 | 30 | 15 | 12 | 6 | Φ410×3 | 585 |
VII.Sludge dehydrator advantages
(1) Adopt independent research and development technology
The main shaft adopts the self-developed technology of taper shaft and variable pitch. The sludge increases the axial and radial bidirectional pressure during the operation of the screw shaft, which improves the dehydration rate and work efficiency. [Read also: Screw Press Sludge Dewatering: An Effective Solution for Wastewater Treatment.
(2) Laser cutting and leveling processing technology
Using laser cutting and leveling technology processing technology, the flatness of the laminated sheet increases the dewatering rate of the equipment, and the sludge cake is dried to clear the water effect, and the stacked screw sludge dewatering machine will not leak mud, run mud, and appear thin mud soup.
(3) Long service life
The body of the sludge dewatering machine is made of 304 stainless steel, which is corrosion-resistant and wear-resistant.
(4) Automated procedures, saving water and electricity, and reducing project costs
Due to the use of low-speed screw extrusion technology, the power consumption is very low. At the same time, it is equipped with an automatic spray system, which avoids clogging and does not require a lot of water to rinse.

VIII. Sludge dehydrator key features
Wastewater Treatment Plants and SewerSystems
DAGYEE is expert in providing superior products,machines and solutions for wastewater treatmentplants and sewer networks.
Industrial Companies
DAGYEE is your experienced, reliable partner forvarious industrial branches and offers a full range ofprocesses,solutions and machines for treatment ofwastewater sludge and waste.
Drinking Water Suppliers
DAGYEE has products and solutions for the treat.ment, storage and distribution of drinking water.
Residentialand Commercialreal Estate
DAGYEE has developed solutions for heating andcooling with wastewater as a regenerative energysource -an important contribution to sustainablebuilding technology.
IX. Sludge dehydrator applications
Screw press dewatering machine is widely used in fruit and vegetable juicing, agricultural waste dewatering, distiller’s grains dewatering, crushing and dewatering of fruit waste and vegetable waste, decomposition of food waste, extrusion dewatering of domestic waste, solid-liquid separation of animal feces, dewatering of pulp, sawdust, and sludge.
The versatility of the Sludge Dewatering Machine allows it to handle a wide variety of sludge types.
It is suitable for:
Industrial wastewater coagulation sedimentation sludge
Urban sewage treatment surplus sludge
Community sewage sludge
Adding chemicals to agglomerate sludge in the water purification plant
Water and fertilizer treatment of surplus sludge
Solid-liquid separation in the factory manufacturing process
Whether dealing with oily sludge, organic sludge, or fibrous sludge, it can adapt and deliver consistent performance.

Contact us:
Name: Ashely Li
Mobile:+8613961861780
Tel:+8613961861780
Whatsapp:8613961861780
Email:info@dagyee.com
Add:Room 302, Building 11-4, Hongyi Road, Xinan Town, Xinwu District, jiangsu Province, China