Engineered For Your Success

The Flottweg C-series
Wastewater Decanter

Full power with reduced energy consumption

Decanter centrifuges for sewage sludge and waste water applications

The demands on the quality and efficiency of sewage treatment plants are growing from year to year, not least due to rising energy and disposal costs. As a result, using decanters to dewater sludge means using state-of-the-art technology. The C-series decanters from Flottweg achieve high performance with reduced energy consumption.

Over the last five decades, Flottweg has acquired a wealth of experience in the field of sewage sludge thickening and dewatering.
We are aware of the special requirements of sewage treatment plants and the water industry. That is why we have developed our own decanter series exclusively for separation tasks in the sewage sludge sector and for the treatment drinking water. This is where our latest insights from the fields of mechanical engineering and manufacturing as well as measurement and control technology come together. A new generation of environmental centrifuges was created, characterized by the well-known Flottweg quality and reliability, as well as an optimal price-performance ratio.

Thanks to the interaction between a powerful and energy-efficient drive, the Flottweg Simp Drive®, and the continuously optimizing decanter geometry, Flottweg decanter centrifuges achieve separation values that are several percentage points higher than those of other models. The right machine is available for every plant size. The further ongoing development of the Flottweg decanter centrifuges guarantees optimum sludge thickening (OSE) and the highest possible sludge dewatering (HTS). 

Application area: sewage sludge and waste water


Municipal waste water and drinking water treatment

Our C-series is used as OSE decanters and HTS decanters in various areas of sludge treatment.

How does a Flottweg C-series Decanter work?

The concept corresponds to the fundamental function of a decanter centrifuge. The Flottweg C-series accelerates the supplied separation medium particularly effectively, thus saving energy. The solids are thrown onto the inner wall of the bowl by acceleration and discharged via the decanter scroll to the conical bowl end.

In contrast to other decanter centrifuges, the C-series decanter have a double cone and a baffle plate. The double cone reduces the distance between decanter bowl and scroll. This presses the solids against the baffle plate and increases the pressing effect. The separated water flows away without pressure along the screw. 

Functionality of a decanter centrifuge

Product features


Behind the designation C-series is a waste water treatment decanter centrifuge with an optimum price/performance ratio. The decanter bowl is designed to increase the volume of sedimentation in the bowl. This increases the power density. Nevertheless, the decanter centrifuge requires only little space.
The special design of the scroll ensures the highest dry solids values in the discharged material. If the DS value can be increased from 23 percent to 25 percent, Flottweg customers achieve a reduction in sludge volume of about eight percent. This also reduces transport and disposal costs by 8% - an enormous savings potential for sewage treatment plants. The powerful Simp Drive® drive supports the performance of the decanter centrifuge. It allows the bowl speed and differential speed to be controlled independently during operation. This ensures a constant dry solids value in the discharged material under varying feed conditions.
The optimized geometry of the bowl and scroll reduces the need for flocculants. This further saves operating costs.

  • High dry solids values in the discharged material
  • Higher power density within a small footprint
  • Powerful Flottweg Simp Drive® drive
  • Reduction of operating costs due to reduced need for flocculant

Power requirements

Our decanters of the C-series are considered to be genuinely economical both in terms of flocculant consumption and energy needs. The special design of the centrifuge and the Simp Drive® drive makes the waste water decanter particularly economical.
The energy consumption of the decanter can be further reduced with the installation of the Recuvane® system. The decanter must consume energy to accelerate the product to the working speed. This is when most of the energy is consumed. After separation, the liquid (centrate) leaves the system pressure-free. The energy contained in the water is lost. Customers recover part of this rotational energy through the Flottweg Recuvane® system.  The special design of the Recuvane® system allows the centrate to be selectively discharged. The energy recovered during the discharge supports the main drive. Depending on the depth of the pond and the composition of the product, 10 to 30 percent of the drive energy can be saved.

  • Additional energy recovery with the Flottweg Recuvane® system
  • Economical bowl and scroll drive
  • Reduces the energy consumption of your decanter by 10 to 30 percent.


The C-series is designed for easily maintenance access. Rotor and scroll can be quickly mounted and dismounted. This reduces downtime and lowers maintenance and service costs. Worn parts can be easily replaced on site. In addition, the decanter centrifuges are equipped with a comprehensive wear protection package. The inlet and outlet openings are especially protected against wear. All components in contact with the product are made of high-quality stainless steel. This additionally extends the service life of the waste water decanter and reduces the expenditure for maintenance and servicing.

  • Fast assembly and disassembly of rotor and scroll reduce service and maintenance costs
  • Comprehensive abrasion protection package
  • All decanter components that are in contact with the product are made of high-quality stainless steel
  • Easy maintenance on site due to simple replacement of wearing parts


Numerous automation options allow the decanter centrifuges to operate 24 hours a day, thus reducing personnel requirements. This in turn reduces costs incurred by the waste water treatment plant. Bowl and differential speeds can be automatically controlled via the Simp Drive®. Fluctuations in the feed can be compensated at any time in order to always achieve optimum dry solids in the dewatered material. 
On request, the dosing of the flocculant can also be automated. The demand is monitored in real time. This reduces polymer consumption and saves operating costs. In addition to a low polymer consumption, all options for remote monitoring and remote service are available - for Enterprise 4.0 operation.
Our C-series decanter centrifuges are part of an overall waste water treatment process. All its components must work together optimally to ensure that the system operates efficiently and safely. Therefore, the centrifuge control of our waste water decanters can be individually integrated into the complete sewage treatment plant control system for more efficiency and operational safety.

  • Minimal personnel required all the way to automatic 24-hour operation
  • Fully automatic regulation of bowl and differential speed at all times for optimum dewatered dry solids
  • On request, all remote monitoring options and maintenance options are available
  • Automatic flocculant dosing additionally reduces polymer consumption (optional)
  • Individual integration of the centrifuge control system into your overall control system for maximum efficiency and operational safety of your plant

Decanter centrifuge wins over belt press

Decanters and belt presses are in constant competition for the dewatering of sewage sludge in sewage treatment plants. 

However, the experience of the West Central Conservancy District sewage treatment plant in Indianapolis speaks for itself.  You can see the results in this video.

Our decanter services and benefits


Mobile dewatering systems

Sludge dewatering within a container - connect and dewater.


Rental machine service

You would like to assure yourself of the performance? Use our rental machines.


Training on the machine

We will show you how you can carry out simple maintenance work on the separator.


Dimensions [mm/ft]*

2700x900x800 / 8,86x2,95x2,62

Weight [kg/lb]*

1400 / 3080


Dimensions [mm/ft]*

3000x1100x900 / 9,77x3,61x2,92

Weight [kg/lb]*

1765 / 3883


Dimensions [mm/ft]*

3500x1100x1000 / 11,55x3,74x3,35

Weight [kg/lb]*

2760 / 6072


Dimensions [mm/ft]*

4100x1500x1200 / 13,35x4,95x3,97

Weight [kg/lb]*

5030 / 11066


Dimensions [mm/ft]*

4800x1700x1400 / 15,74x5,64x4,56

Weight [kg/lb]*

8200 / 18040


* The values are approximate and may differ from the actual values.

Dimensions [mm/ft]*

5900x2000x1500 / 19,39x6,56x4,82

Weight [kg/lb]*

13070 / 28754

Features for process optimization


Decanter scroll

The scroll is the conveying tool in the decanter or Tricanter®. Subjected to a centrifugal force, solids settle on the inner wall of the bowl. For best separation results, Flottweg offers individual scroll geometries as well as a large selection of different scrolls based on decades of experience.

About the decanter scroll

Decanter bowl

The medium reaches the maximum speed in the decanter bowl, which causes the solids to settle on the inner wall of the bowl. The decanter bowl of the C-series is specially designed to meet the needs of sewage and water treatment plants - with an increased sedimentation volume and a longer clarification section.

More information about the decanter bowl

Wear protection

Flottweg offers various types of wear protection to reduce wear and abrasion to a minimum. This extends the service life of the decanter. Maintenance costs are reduced because only wearing parts have to be replaced.

For wear protection

Simp Drive®

The Simp Drive® drive regulates the differential speed between the decanter bowl and scroll as a function of the prevailing scroll torque. The differential speed defines the residence time of the solids in the bowl and thus has a considerable influence on the separation process. Simp Drive® offers a high economic efficiency due to a consistently high dry solids value (DS) - the higher this value, the drier the separated solids will be. 

Here you can find more information about Simp Drive®

Pond depth

An optimally set pond depth causes a higher dehumidification of the solids and thus an improved product result. Our decanters for waste water treatment are equipped with a deep pond for higher clarification performance and optimum separation of solids and water.

More about pond depth


With Flottweg's Recuvane®, some of the energy that is normally lost when the treated water drains away can be recovered. The energy is then returned to the main drive.

More about the Flottweg Recuvane®


The closed design of the Flottweg decanter centrifuges prevents the escape of dirt or odors. The sealing of the centrifuges shields the environment against odor nuisance and sewage sludge aerosols. Depending on the application, there are various options for sealing.

More about sealing

Overflow weir

The clarified liquid runs off through openings in the bowl cover in which precisely adjustable weir plates are located. These can be used to adjust the pond depth in the bowl.

About overflow weir

Would you like to know more about our waste water decanters?

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