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
  • Homogenization and solid suspension
  • Agitation in aerobic and anoxic mixing
  • Sludge mixing and prevent floating crust
Submersible mixer type ABS XRW 210 to 900 hotspot image

Main design features
  • Optimized propeller designs ensure superior mixing performance
  • Pioneering efficient motor options such as PMSM deliver low energy consumption
  • Innovative self-cleaning propellers reduce maintenance requirements and improve reliability
  • Smart features designed to inform preventative maintenance decisions
  • Range of sizes ensures a cost-effective solution to suit all wastewater mixing applications
  • Easy installation and retrofitting
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 equipped 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
  • Sulzer provided premium efficiency mixing solutions for high-level wastewater treatment
    The Aquaviva wastewater treatment plant receives effluents from eight cities around Cannes and treats almost 16 million m³ wastewater annually. The process is optimized through the variable speed and constant torque of a Sulzer self-cleaning mixer.

  • Sulzer provides turnkey mixer installation to improve reliability and energy efficiency
    Wastewater treatment works (WWTWs) need to operate around the clock, and all the processes require electrically powered equipment to transport and treat the water. As such, reliability and efficiency are key priorities so when a pair of mixers used in the activated sludge process (ASP) of a large plant experienced fundamental reliability issues, the operator turned to Sulzer for a more effective solution. The turnkey installation of the company’s XRW mixers offered an extended service life and provided the potential for energy savings of up to 25%.

  • Case studies
    Wherever fluids are pumped, mixed, controlled or applied, we are there. See how our solutions create value for customers and learn how we can make your pumping and mixing processes more efficient and profitable, safeguarding your production and ensuring lasting reliability.
  • 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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