Biogas Pre-Processing · Agitators
Agitators
Submersible Mixer
A submersible propeller mixer that keeps the digester moving — holding solids in suspension so conditions stay homogeneous throughout the tank, and preventing the sedimentation and settling that would otherwise cut digester efficiency and biogas output. Nine models in cast iron and stainless steel, 2 to 15 HP, with propellers from 260 to 790 mm.
- Motor power
- 2 – 15 HP (1.5 – 11 kW)
- Propeller diameter
- 260 – 790 mm
- Propeller speed
- 232 – 980 rpm
- Thrust
- 290 – 2900 N
What it’s for
Keeping the Digester Homogeneous
Feedstock left undisturbed separates. Heavier solids settle to the floor of the digester and lighter material floats, and both reduce the volume actually taking part in digestion — so gas output falls while the tank fills with material that isn't working. An agitator holds the contents in suspension so the whole volume stays active.
The propeller produces a low tangential flow with force, rather than a violent stir: enough movement to keep solids suspended and to circulate the tank, without the energy cost of high-speed mixing. The blade is self-cleaning, so fibrous material can't twine around it or block it, and the mechanical seal is corrosion-resistant tungsten carbide. Paired with an aerator in a treatment tank, the same movement raises the aeration rate while lowering overall energy consumption.
Construction
How It’s Built
Specifications
Technical Data
- PM-260/980-2.0
- 1.5 kW / 2.0 HP · 4 A · 260 mm propeller · 980 rpm · 290 N thrust · 65 kg
- PM-320/740-3.0
- 2.2 kW / 3.0 HP · 5.9 A · 320 mm propeller · 740 rpm · 582 N thrust · 70 kg
- PM-320/960-5.0
- 4 kW / 5.0 HP · 10.3 A · 320 mm propeller · 960 rpm · 609 N thrust · 70 kg
- PM-640/232-7.5
- 5.5 kW / 7.5 HP · 13.5 A · 640 mm propeller · 232 rpm · 1800 N thrust · 230 kg
- PM-640/303-10.0
- 7.5 kW / 10.0 HP · 17.5 A · 640 mm propeller · 303 rpm · 2600 N thrust · 275 kg
- PM-790/303-15.0
- 11 kW / 15.0 HP · 25.4 A · 790 mm propeller · 303 rpm · 2900 N thrust · 200 kg
- PM-620/480-5.0
- 4 kW / 5.0 HP · 14 A · 620 mm propeller · 480 rpm · 1400 N thrust · 230 kg
- PM-620/480-7.5
- 5.5 kW / 7.5 HP · 18.2 A · 620 mm propeller · 480 rpm · 1800 N thrust · 230 kg
- PM-620/480-10.0
- 7.5 kW / 10.0 HP · 27 A · 620 mm propeller · 480 rpm · 2600 N thrust · 275 kg
Cast iron mixers — six models
Stainless steel mixers — three models
- Voltage / phase
- 415 V / 3 ph
- Speed range
- 232 – 980 rpm
- Protection
- IP 68
- Insulation
- Class F
- Duty
- S1 (continuous)
- Medium temperature
- 40 °C maximum
- Cable length
- 10 m
- Blade
- Self-cleaning — prevents debris twining or blocking
- Mechanical seal
- Corrosion-resistant tungsten carbide
- Housing
- Cast iron or stainless steel, by model
- Installation
- Compact and light — simple to install and maintain
- Worked example
- PM-260/980-2.0
- PM
- Submersible mixer
- 260
- Propeller diameter, in mm
- 980
- Propeller speed, in rpm
- 2.0
- Motor power, in HP
Electrical
Construction
How to read the model code
Applications
Where It’s Specified
Maintains homogeneous conditions throughout the digester, preventing the sedimentation and settling that would otherwise reduce efficiency and biogas output — working with the uniform slurry the macerator delivers.
Municipal sewage treatment plants and industrial wastewater treatment plants, producing a low tangential flow with force to keep tank contents circulating.
Creates the circulating flow these stages depend on, and is used in phosphorus removal for the same reason.
Run together with an aerator, the mixer raises the aeration rate while lowering energy consumption across the pair.
Common questions
Frequently Asked Questions
Cast iron or stainless steel?
Cast iron covers the full range — six models from 2 to 15 HP, with propellers from 260 to 790 mm. Stainless steel is offered in three models from 5 to 10 HP, all on a 620 mm propeller at 480 rpm, for duties where corrosion resistance matters more than reach of range.
How do I read the model number?
PM-260/980-2.0 reads as: submersible mixer, 260 mm propeller, 980 rpm, 2.0 HP. The code carries the three numbers that decide the duty, so sizing can be checked straight off the model.
What stops fibrous material fouling the blade?
The blade is self-cleaning, so debris can't twine around it or block it, and the mechanical seal is corrosion-resistant tungsten carbide. Both matter on feedstock that has already been through shredding and maceration but still carries fibre.