HUBER Disc Dryer RotaDry®: Trial disc dryer for small-scale tests

The HUBER Disc Dryer RotaDry® is designed for homogeneous partial drying of dewatered sewage sludge. Due to its compact design and high specific water evaporation, it is ideally suited not only for use in new sewage sludge mono-incineration plants, but also for capacity expansions of existing plants. The dryer can dry exactly to the required DR content, thus enabling self-sustaining combustion in the fluidised bed incinerator. The HUBER Disc Dryer RotaDry® is available in different sizes, so that a water evaporation of two to six tons per hour and dryer can be achieved.

The perfect sewage sludge dryer in combination with a mono-incineration plant

By using different disc diameters and numbers of discs, the dryer surface can be optimally adapted to the amount of generated sludge and the dryer can be operated in the ideal capacity range. Thermal drying of sewage sludge is an indispensable process component to ensure the sewage sludge has the right dry residue. The subsequent mono-incineration of the sewage sludge achieves an enormous reduction in volume and mass and provides for the recovery of phosphorus. At the same time, the heat required for drying is provided and, depending on the size of the plant, electricity is also generated by means of a steam turbine. A reliable condensate removal system, an innovative concept for moisture control, optimized feeding and a steam control line with minimized pressure loss characterize the HUBER Disc Dryer RotaDry® as the perfect sewage sludge dryer in combination with a mono-incineration plant.

New RotaDry® trial disc dryer enables drying of sewage sludge on a pilot scale

The project-specific assessment of sewage sludge drying is extremely important to assess risks and optimise process designs. For this reason, HUBER SE decided in 2021 to develop a compact trial disc dryer. Together with its cooperation partner Oestergaard, HUBER downscaled the dryer and adapted the throughput to the size of a test plant. The aim was to design a transportable dryer that can be used for testing purposes at the headquarters in Berching, Germany, as well as for more extensive tests at interested customers' sites. The limiting factor here is the sludge throughput of the dryer, as not unlimited amounts of dewatered sewage sludge can be shipped to Berching for tests.

HUBER Disc Dryer RotaDry® in a 20-foot high-cube container

The 20-foot high-cube container houses the disc dryer, the feed and discharge screw, a small shell-and-tube condenser and the vapour extraction fan. The HUBER Screw Conveyor Ro8 T units of size 219 are of course "Made in Berching" and have been manufactured directly in HUBER's adjacent production hall.

Unlike its large, steam-heated "dryer brothers", the disc dryer is heated with thermal oil. HUBER was able to use an electrically heated thermal oil unit from its stock, which offers advantages over a steam generator, especially due to its easier handling. In addition, a control cabinet is installed in the container, which houses the electrical instrumentation and control (I&C) technology. To operate the dryer, only a 63 A power supply and cooling water are required externally.

 
If you are interested in a customised test with the trial disc dryer, please contact HUBER Sales, Sludge Drying at sludge@huber.de.