Screw Press Sludge Dewatering Machine Supplier in Bangladesh
TECHANGE multi-plate screw press for ETP and STP sludge. Continuous, self-cleaning and low on wash water, supplied with installation and after-sales support by Techno Bangla Creation.
What Is a Screw Press for Sludge Dewatering?
A screw press for sludge dewatering is a machine that squeezes water out of flocculated sludge using a slowly turning screw inside a stack of fixed and moving rings. Water drains through narrow gaps while the solids are pressed into a drier cake. It runs continuously, and the moving rings clean the gaps as they turn.
A screw press does not remove the sludge itself. It removes water, so the sludge is lighter and cheaper to haul. For the driest cake, a batch filter press is the usual choice. A screw press is a better fit when you want continuous, low-labour dewatering.
- Self-cleaning rings that resist blocking
- Low wash water and a slow, low-energy screw
- Suited to ETP, STP, textile, paper, pharmaceutical and food sludge
- Installation and after-sales support in Bangladesh
Screw Press Sludge Dewatering Machine Specifications
- Type
- Multi-plate (multi-disc) screw press, continuous operation
- Capacity
- 5 kg/h ~ 640 kg/h
- Application
- ETP, STP, paper mill, textile, pharmaceutical, food and beverage
- Typical industry result
- Feed of about 0.5 ~ 5% solids, cake of about 18 ~ 25% dry solids
- Brand
- TECHANGE
- Origin
- China
Screw press capacity is normally quoted as kilograms of dry solids per hour. The "typical industry result" is a general range for multi-disc screw presses, not a guarantee. Cake dryness, power, size and materials depend on the model and your sludge. Send us a sludge sample or lab data and our engineers will confirm the datasheet values.
How Does a Multi-Disc Screw Press Work?
- Polymer Flocculates the SludgeA dosing unit adds polymer in a flocculation tank, so fine solids join into larger flocs.
- Sludge Enters the ScrewThe flocculated sludge flows into the concentration zone of the screw barrel.
- Water Drains Through the GapsFree water escapes through narrow gaps between the fixed and moving rings.
- Pressure Builds Toward the OutletThe screw pitch and ring gaps shrink, so the sludge is squeezed harder as it moves.
- Rings Self-Clean, Cake DischargesMoving rings shift against fixed rings and clear the gaps. The drier cake leaves at the end.
Screw Press vs Belt Press vs Filter Press
All three remove water from sludge. They trade dryness, speed and labour differently.
| Feature | Screw Press | Belt Filter Press | Plate Filter Press |
|---|---|---|---|
| Operation | Continuous, slow, can run with little supervision | Continuous, needs closer supervision | Batch, with fill, press and discharge cycles |
| Typical cake dryness | About 18 ~ 25% dry solids | About 18 ~ 28% dry solids | Highest of the three, often 25 ~ 40% dry solids |
| Wash water | Low, because the rings self-clean | High, because belts are washed continuously | Cloths are washed between cycles |
| Energy use | Low, due to the slow screw | Higher than a screw press | Driven mainly by the feed pump |
| Throughput | Low to medium | High | Medium, limited by cycle time |
| Clogging risk | Low, moving rings clear the gaps | Oil and grease can blind the belt | Cloth can blind and needs washing |
| Best fit | Small and medium ETP and STP, minimal labour | Large, high-flow plants | Maximum dryness to cut disposal volume |
Values are typical figures from equipment-maker and engineering guides. Results vary with sludge type and polymer conditioning. See our filter press for batch dewatering.
Which Sludge Can a Screw Press Handle?
Sludge type decides how well any dewatering machine performs.
| Sludge type | Fit | Note |
|---|---|---|
| Biological (activated) sludge from ETP and STP | Good | Needs polymer conditioning |
| Chemical sludge from coagulation, such as dyeing effluent | Good | Run a jar test to pick the polymer |
| DAF float and oily sludge | Common use | The self-cleaning rings suit greasy sludge |
| Food, paper and pharmaceutical sludge | Good | Listed applications for this machine |
| Sandy or gritty sludge | Poor | Grit wears the rings, so remove it upstream first |
| Very thin sludge, under about 0.5% solids | Pre-thicken | Thicken with a settler or DAF before the press |
This is a general guide. Confirm the feed solids range and sludge limits on the datasheet of the exact model.
Key Benefits
A dewatering machine you do not have to babysit is worth more than a fast one.
- Continuous process that can run with little operator attention
- Self-cleaning rings that resist blocking and cut flushing water
- Slow screw, so energy use is generally lower than belt press or centrifuge
- Lighter, drier sludge cake means fewer trips and lower haulage cost
- Compact body suits small and medium plants with limited space
- Local engineering and after-sales support from Techno Bangla
Is a Screw Press Right for Your Plant?
Choose a Screw Press When
- Your sludge comes from an ETP or STP and flow is small to medium
- You want continuous dewatering with little labour
- Wash water and power are limited or costly
- Floor space is tight
- You can run a polymer dosing programme
Choose Another Machine When
- You need the driest cake possible. Use a filter press
- Sludge flow is very high, as in a large municipal plant
- Your sludge is sandy or gritty and cannot be de-gritted
- You cannot dose polymer
- A small sludge volume is already handled by drying beds
Where Screw Presses Are Used
Any plant that ends its treatment with a wet sludge to dispose of.
- Textile and Dyeing ETP
- Garment Factory ETP
- STP Sludge
- Paper Mill
- Pharmaceutical Plant
- Food and Beverage
- DAF Float Sludge
- Oily Sludge
How to Choose the Right Screw Press
Share these details with our engineers and we will recommend a suitable model and size.
- Sludge type and solids. Biological, chemical or oily sludge behave differently. Give us the feed solids percentage, or a lab test.
- Capacity in dry solids. Dry solids (kg/h) is about sludge flow in m³/h times solids % times 10. For example, 2 m³/h at 1% solids is about 20 kg/h.
- Polymer conditioning. Plan a flocculation tank and polymer dosing. A jar test picks the polymer. See our dosing pumps and mixing agitator.
- Feed pump. Use a pump that does not shear the flocs. See our air operated diaphragm pump.
- Materials, power and cake handling. Ask for the ring material, confirm the power supply (380 V, 3-phase, 50 Hz is common in Bangladesh), and plan where the cake goes.
Why Sludge Dewatering Matters for Bangladesh ETPs
Proper sludge management is mandatory under the Bangladesh Environment Conservation Act, 1995 (amended 2010). The DoE sludge guidelines ask industries to submit a sludge management plan and to reduce sludge volume before disposal.
Training material for ETP operators notes that some Bangladesh ETPs have no sludge dewatering at all, and many rely on filter presses or drying beds. A screw press gives a continuous option. See our ETP plant and sewage treatment plant pages.
Installation and After-Sales Support
Techno Bangla Creation supplies treatment plant equipment together with installation, commissioning and after-sales support for factories, businesses and organizations across Bangladesh.
Our team is based in Mohakhali, Dhaka. Send your sludge type, flow and solids, and our engineers will recommend a suitable screw press, polymer dosing set and feed pump.
Frequently Asked Questions
What is a screw press for sludge dewatering?
A screw press for sludge dewatering is a machine that squeezes water out of flocculated sludge using a slowly turning screw inside a stack of fixed and moving rings. Water drains through narrow gaps while the solids are pressed into a drier cake. It runs continuously, and the moving rings clean the gaps as they turn.
How does a multi-disc screw press work?
Polymer-treated sludge enters a screw barrel built from fixed and moving rings. Water drains through the gaps while the screw carries the solids forward. The screw pitch and ring gaps shrink toward the outlet, so pressure rises and a drier cake discharges. The rings move against each other and clear the gaps.
How dry is the cake from a screw press?
Industry guides put screw press cake at about 18 to 25% dry solids, depending on sludge type and polymer. That is close to a belt press, which is usually 18 to 28%. A plate filter press normally gives a drier cake. Your exact result depends on your sludge, so a trial or lab test helps.
Which is better, a screw press, belt press or filter press?
A screw press suits small and medium plants that want continuous, low-labour dewatering with little wash water. A belt press suits high flow. A filter press gives the driest cake but runs in batches. Choose by your sludge flow, the dryness you need and the labour you have.
Does a screw press need polymer?
Yes, in almost every case. Polymer flocculates the fine solids into larger flocs that the screw can hold while water drains away. The right polymer and dose depend on your sludge, so a jar test is the usual first step. A dosing pump and flocculation tank complete the set.
What does a capacity of 5 to 640 kg/h mean?
Screw press capacity is normally quoted as kilograms of dry solids per hour, not litres of sludge. To convert, multiply sludge flow in m³/h by the solids percentage and by 10. For example, 2 m³/h of 1% sludge is about 20 kg/h. Our engineers confirm the basis on the datasheet.
What maintenance does a screw press need?
Self-cleaning rings keep flushing needs low, but the rings are wear parts. Abrasive or gritty sludge wears them faster, and ring material affects life. Plan regular checks of the rings, screw, seals and polymer system, and remove grit upstream. Ask us for a spare-parts list with your quotation.
How can I get a quotation for a screw press?
Send your sludge type, flow, feed solids percentage and power supply to our engineers by phone or email. We reply with a free quotation for your ETP, WTP, STP or water treatment equipment.
