Advanced sludge dewatering equipment including multi-disc presses and screw conveyors for effective water removal, volume reduction, and solids handling.
Groundwater treatment for tunnel dewatering operations. Remove suspended solids, adjust pH and manage contaminated water.
Dewatering water treatment for pits, tunnels and underground mines.
Complete sludge handling solutions. Thickening, dewatering, drying and disposal preparation for wastewater treatment plants.
Sludge management solutions including thickening, dewatering, and disposal.
Mechanical Water Removal Process
Sludge dewatering reduces volume by separating bound and free water from a porous solid matrix. Free water drains under gravity; capillary and surface-bound water require mechanical pressure or shear. Each percent increase in dry solids (DS) typically halves the residual mass that must be transported to disposal.
2–5% DS
Cationic polymer 3–8 g/kg DS
Pressure & shear
18–25% DS
Cake Filtration, Specific Resistance and Polymer Conditioning
Mechanical dewatering follows the classical cake filtration model. Filtrate flux is governed by Darcy’s law applied across a growing compressible cake of conditioned solids.
Instantaneous filtrate flux:
dV/dt = A·ΔP / [μ·(α·c·V/A + Rm)]
where ΔP is the applied pressure, μ water viscosity, c the dry solids concentration, α the specific cake resistance and Rm the medium resistance. Pressing time per cycle scales with V2, which is why thin-cake, high-shear devices outperform deep-cake batch presses on flux.
Sludge filterability is captured by the specific resistance to filtration, α (m/kg). Raw activated sludge: 1013–1015 m/kg — effectively undewaterable. Cationic polymer conditioning reduces α by 2–3 orders of magnitude (≤1012 m/kg) by neutralising the negative surface charge (zeta potential typically −15 to −25 mV) and bridging EPS-bound flocs.
Real sludge cakes are compressible: α = α0·(ΔP)s. The compressibility coefficient s typically ranges 0.6–1.0 for biological sludge and 0.2–0.5 for primary or chemical sludge. Above a critical pressure (5–7 bar for waste activated sludge) the cake collapses and additional pressure yields diminishing – even negative – returns, which sets the design envelope for screw and disc presses.
| Technology | Feed DS | Cake DS | Polymer (g/kg DS) | Driving Force | Solids Capture |
|---|---|---|---|---|---|
| Gravity belt thickener | 0.5–1% | 4–7% | 2–5 | Gravity drainage | ≥95% |
| Rotary drum thickener | 0.5–1% | 5–8% | 3–6 | Gravity + drum shear | ≥95% |
| Multi-disc screw press | 2–5% | 18–25% | 3–8 | Compression in tapered channel | ≥97% |
| Belt filter press | 2–5% | 18–25% | 4–9 | Belt tension 5–8 N/mm | 92–97% |
| Decanter centrifuge | 2–5% | 22–32% | 5–10 | 2,500–3,500 g | 92–97% |
| Plate & frame filter press | 4–6% | 30–50% | 2–6 + lime/FeCl3 | 10–16 bar batch | ≥99% |
Ranges are typical for municipal mixed primary + WAS; industrial and digested sludges shift the envelope. CST (Capillary Suction Time) and time-to-filter (TTF) jar tests should be used to fix the design polymer dose during pilot work.
Modern sludge dewatering device using innovative construction of moving and static discs. Effective, energy-efficient water removal. Low operating overheads, quiet operation, minimal chemical consumption.
Sludge inlet
Gravity drainage
Disc compression
Dry solids out
Moving and static discs create self-cleaning filtration zones
Low power consumption compared to belt and centrifuge systems
Fully automated operation with minimal supervision required
Enclosed design minimises odour emissions
Reliable screenings transport from press to disposal. Simple, robust construction ensures smooth process flow minimising blockage risk. Low energy consumption, easy operation, high durability.
SCADA Integration Available
Our dewatering equipment can be fully integrated with SCADA systems for automated operation and monitoring. Track sludge feed rates, monitor cake dryness, receive maintenance alerts, and optimise polymer dosing from a centralised control interface.
Reduce Disposal Rates
Dewatering reduces sludge volume by 70-90%, significantly cutting transportation and disposal expenses
Multi-disc press technology uses significantly less energy than centrifuges or belt presses
Simple mechanical design reduces spare parts inventory and maintenance labour costs
Efficient design requires less polymer for conditioning compared to other dewatering methods
Select the Right Equipment for Your Application
| Parameter | Multi-disc Press | Belt Press | Centrifuge | Screw Press |
|---|---|---|---|---|
| Energy Consumption | Very Low | Medium | High | Low |
| Noise Level | Very Low | Medium | High | Low |
| Water Consumption | None | High | None | None |
| Chemical Requirement | Minimal | Medium | Medium | Low |
| Operator Attention | Minimal | High | Medium | Low |
| Maintenance | Low | High | High | Low |
| Odour Control | Enclosed | Open | Enclosed | Enclosed |
Meeting Industry Standards
Food processing, pulp & paper, textile, chemical, and pharmaceutical industry sludge
Primary and secondary sludge dewatering at municipal wastewater treatment plants
All equipment meets European machinery directives and safety standards
Energy-efficient design supports sustainability goals and carbon reduction
Complete Your Treatment System
Automated polymer preparation for optimal sludge conditioning.
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View Lamella SeparatorScientific guides to thickening, conditioning, dewatering, stabilisation, drying and disposal compliance
Gravity and mechanical thickening, the solids-flux function and limiting-flux sizing for gravity, drum and belt thickeners.
View GuideCharge demand, capillary suction time and polymer optimisation that govern cake dryness and capture.
View GuideBelt, screw, filter and multi-disc presses and centrifuges compared on cake solids and capture rate.
View GuideVolatile-solids reduction, biogas yield and pathogen reduction toward energy-neutral treatment.
View GuideHeat and mass balance, the latent-heat demand and heat recovery for high dry-solids product.
View GuideLand application, pathogen and vector-attraction classes, metals limits and disposal-route rules.
View GuideContact Our Engineers to discuss your sludge dewatering requirements and find the most efficient solution for your application.
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