Which devices are the main energy consumers of DAF Sludge Dewatering System

Screw-type or reciprocating air compressors

Typically 7.5–30 kW per unit, depending on air flow (10–50 Nm³/h)

Isothermal inefficiency (20–30% heat loss), pressure drop in pipelines (>0.1 MPa), and unloaded cycling during pressure stabilization.

Example: A 22 kW compressor running at 8 bar consumes ~180 kWh/day, with 60 kWh lost to thermal dissipation.

Centrifugal pumps for recirculating process water (3–15 m³/h) and pressurizing dissolved air

5.5–18.5 kW per pump, influenced by head pressure (15–40 m) and recirculation ratio (15–30% of influent flow)

Cavitation erosion (reducing pump efficiency by 10–15% over 6 months) and friction losses in narrow-diameter pipes ().

Example: A 11 kW pump operating at 30 m head may waste 3.3 kWh/day due to impeller wear.

Mechanical agitators (paddle or turbine types) and static mixers

2.2–7.5 kW per agitator, dependent on tank volume (50–200 m³) and mixing intensity (tip speed 1–3 m/s)

Viscous drag from high-solids sludge (up to 5% TS), requiring 2–3 times more power than clear water mixing.

Example: An agitator in a 100 m³ tank with 3% TS sludge consumes ~50 kWh/day, 40% more than standard water applications.

Sludge transfer pumps (progressive cavity or lobe types), belt filters, or centrifuges

Transfer pumps (3–11 kW) and dewatering equipment (15–55 kW for centrifuges)

Sludge viscosity—thickened sludge (8–10% TS) requires 50% more pump power than raw sludge (1–3% TS).

Example: A 7.5 kW transfer pump for 10% TS sludge may consume 180 kWh/day versus 120 kWh for 3% TS.