Screw Press Sludge Dewatering Machine Supplier in BD
Turn watery ETP and STP sludge into a lighter, easier-to-haul cake. The TECHANGE screw press runs continuously, cleans its own rings and sips wash water. Techno Bangla Creation Ltd. supplies it, installs it and stays after the handover.
What Is a Screw Press for Sludge Dewatering?
The TECHANGE screw press squeezes water out of polymer-treated sludge. A slow screw pushes the sludge through stacked fixed and moving rings. Water slips out through tiny gaps while the solids compress into cake. Ring movement wipes the gaps clean, so the machine rarely clogs and rarely needs a flushing crew.
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.
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.
Frequently Asked Questions
How much does a TECHANGE screw press cost in Bangladesh?
Price depends on capacity (5 ~ 640 kg/h), ring and body material, motor, control panel and the polymer and feed system you add. We quote per sludge and per plant, not from a flat list. Send flow, solids percentage and power supply, and engineers reply with a free quotation.
What are the disadvantages of a screw press?
The cake is usually wetter than a filter press gives. It needs polymer almost every time. Sandy or gritty sludge wears the rings, and very high flows need other machines. In one full-scale municipal test, a decanter reached 22.7% cake solids against 18.1% for a screw press, though the screw press used far less power.
Is a screw press cheaper to run than a decanter centrifuge?
Often yes on electricity, not always overall. The same municipal comparison found about six times lower direct power for the screw press, but the decanter cut polymer use by about 60% and wash water by about 3.2 times. Cheaper to run depends on your power tariff, polymer price and how much you pay to haul sludge.
Can a TECHANGE screw press handle oily or DAF sludge?
Yes. Oily and DAF float sludge is a common use, because moving rings wipe the gaps clear instead of letting grease blind a screen. Polymer choice matters more here, so run a jar test first. Heavy grit is the real enemy, not grease.
How much polymer does a screw press use?
An industry guide puts activated-sludge dewatering at about 3 to 8 kg of polymer per tonne of dry solids. Your number depends on sludge age, solids and polymer type. Bench-test before you order, and ask us to size the dosing pump and flocculation tank with the press.
What must be ready before the machine arrives?
A flocculation tank with polymer dosing, a feed pump that will not shear the flocs, a 380 V three-phase supply, a drain line for the filtrate back to the ETP, and a bin or trolley for the cake. Remove grit upstream. Our engineers check this list during site survey.
Who supplies spare parts and service in Bangladesh?
Techno Bangla Creation handles installation, commissioning and after-sales support from Dhaka. Rings and seals are the wear parts, so ask for a spare-parts list with your quotation and keep a set on site.
Can I test my sludge before buying?
Yes, start with a jar test on your sludge to choose polymer and dose. Send a sample or lab data (flow, solids %, sludge type) and our engineers confirm which model suits it and what cake to expect. Treat any dryness figure as a range until it is measured on your sludge.
