5 tanks, 3 technologies, 1 solution: Tailor-made agitation technology in perfect coordination

16 July 2026 | SUMA Rührtechnik GmbH

• Energy

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As part of the renovation of a biogas plant in the Netherlands, SUMA implemented a customized agitation concept that is precisely tailored to the requirements of the five biogas tanks with three different types of agitators.

The plant has a total volume of around 10,000 m³ and processes approximately 72,000 tons of substrate per year with a dry matter content of between 8 and 14%. Feeding, consisting of animal manure and pasture products, takes place at thirty-minute intervals. In the future, 2,250 m³/h of biogas will be produced, of which 750 m³/h will be used on site for power generation via a CHP system and 1,500 m³/h will be processed into biomethane.

End-to-end project management from a single source
As part of the plant setup, SUMA was responsible for the technical design carried out by its in-house engineering team, as well as the delivery, installation, and commissioning of the agitators by qualified service technicians.

Combined agitator technologies in perfect harmony
The selection of the respective agitator types is based on the respective tank and substrate parameters as well as flow analyses using CFD simulations from SUMA.

In four of the five tanks, GIANTMIX FT long axis agitators and ASTRAMIX paddle agitators are used in combination. The long axis agitators installed on the sides ensure horizontal movement of the substrate thanks to their high thrust. This type of agitator is the only one in the world that can be adjusted horizontally and vertically up to +/- 30°.

Thanks to its modular design, the long axis agitator can be individually configured and is available with different geared motors from 15.0 to 18.5 kW and pipe lengths from 4 to 6CFD simulation comparison: on the right, with a central mixer to stir the entire tank.CFD simulation comparison: on the right, with a central mixer to stir the entire tank. m.

The supplementary paddle agitators cause the targeted dissolution of floating and sinking layers as well as vertical mixing of the tank. With a motor power of 15 kW, the agitator is suitable for a dry matter content of up to 15%.

Flexible product portfolio for complex tank geometries
Another tank posed special challenges due to its four internal columns. Initially, it was designed exclusively with long axis agitators. CFD simulation showed, nonetheless, that the columns completely shielded the center of the tank, creating a dead zone. Thanks to SUMA's wide range of products, it was possible to use the Z-MIX central mixer as an optimization solution, ensuring that the area between the columns could also be mixed effectively. With its flow-optimized paddles, the Z-MIX ensures axial mixing effects.The central mixer is available with a motor power of up to 55 kW and a nominal speed range of 10-60 rpm.