Submersible mixer type ABS XRW 210 to 900

Submersible mixers for wastewater treatment

The XRW submersible mixer range is our premium range of submersible mixers with outstanding life-cycle economy and superior reliability. The range provides solutions to match mixing tasks in industry, municipal wastewater treatment plants and agriculture.

XRW submersible mixers for wastewater treatment mixing applications
Main benefits
  • Lowest energy consumption
  • Compact, water pressure-tight design
  • Full stainless steel version available
  • Shorter mixing times
  • Minimal risk of motor overloading
  • Superior reliability and long operating life
  • Easy installation
  • Small space requirements
  • As an option, triple seal system with dual oil chamber enhances motor protection for full peace of mind
Main applications
  • Mixing and stirring applications in wastewater treatment plants and industrial areas
  • Homogenization of highly-concentrated sewage sludge

Main design features
  • Easy installation
  • Small space requirements
  • Integral Premium Efficiency IE3 motors or equivalent from 0.8 to 25 kW (1.2 - 35.5 hp)
  • Mechanical seal protected by a solids deflection ring
  • Seal monitoring using multiple sensors
  • Thermo-Control System (TCS) provides timely warnings and auto switch-off
Key characteristics

XRW range

Mixing flow 0.23 - 1.79 m3/s (3'650- 28'300 USgpm)
Propeller diameter 210 - 900 mm (8 in. - 3 ft.)
XRW 210-300

The high-speed submersible mixer range XRW 210 and XRW 300 are equiped with squirrel-cage induction motor of IE3 standard.


50 Hz (IE3) 60 Hz (IE2 / IE3)
Propeller diameter 210 / 300 mm  8 / 12 in (210 / 300 mm)
Motor power 0.8 – 2.9 kW 1.2 – 4.7 hp (0.9 – 3.5 kW)
Motor efficiency up to 85% up to 85%
Mixing flow up to 0.23 m3/s up to 3'650 USgpm (up to 0.23 m3/s)
XRW 330, 400, 480 and 650

In the medium-speed range XRW 330, 400, 480 and 650, IE3-equivalent permanent-magnet motors provides the lowest possible energy consumption.


50 Hz (IE3 equivalent) 60 Hz (IE3 equivalent)
Propeller diameter 330 / 400 / 480 / 650 mm 13 / 16 / 19 / 26 in. (330 / 400 / 480 / 650 mm)
Motor power 3 – 10 kW 4 – 13.4 hp (3 – 10 kW)
Motor efficiency up to 91% up to 91%
Mixing flow up to 0.83 m3/s up to 13'200 USgpm (up to 0.83 m3/s)
XRW 750 and 900

The medium-low speeds mixer range XRW 750 and XRW 900, are equipped with squirrel-cage induction motor of IE3 standard and a gear box as speed reducer.


50 Hz (IE3) 60 Hz (IE3)
Propeller diameter 750 / 900 mm 30 / 35 in. (750 / 900 mm)
Motor power up to 22 kW up to 33.5 hp (up to 25 kW)
Motor efficiency up to 92.3% up to 93%
Mixing flow up to 1.79 m3/s up to 28'300 USgpm (up to 1.79 m3/s)
Case studies
  • Biological process
    The target of the biological process in wastewater treatment is to remove organic, biodegradable substances via the metabolism of microorganisms and related biochemical processes.

  • Equalization
    The task of mixing in the equalization process is to blend the wastewater in order to prevent sedimentation, stratification and odor formation. It may also be necessary to mix and homogenize wastewater streams that arrive from different sources. Because the water level in the equalization tanks varies significantly and can sometimes be very low, high demands are placed upon the mixers.

  • Selector
    The purpose of the selector tank is to control and limit the growth of filamentous bacteria, and then to enhance the sedimentation ability of the sludge. Sulzer provides a number of solutions for creating optimal conditions in the selector.

  • Sludge buffer tank
    The sludge buffer tank can be used for a variety of purposes. The most common application is the blending and homogenization of highly concentrated primary, secondary or digested sludge. The solution used to mix the sludge itself, or to mix the sludge with the dosed thickening chemicals, depends on the design and volume of the sludge buffer tank. Submersible mixer types ABS XRW and RW, as well as the agitator type Scaba, can be used to provide highly efficient mixing. Positive displacement, progressing cavity transfer pumps and Muffin Monster™ grinders are used for solids reduction and sludge transfer from sludge feed to sludge dewatering process.

  • Tertiary treatment
    Treated wastewater may occasionally require further treatment. Local discharge rules may pose strict limits that cannot be fulfilled by even the most effective process, or a higher quality of effluent may be requested for its reuse. When tertiary treatment is needed, various levels of filtration can be applied, including very fine filtration. Often, however, a final step of mixing and aeration is sufficient to achieve the target. When this is the case, Sulzer's submersible mixer types ABS XRW and RW can be used, along with submersible aerator type ABS TA–TAK and disc diffuser system types ABS PIK, DS and Sucoflow.

Data sheets

Dimension drawings


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