Sludge Drying Project Holenbrunn, Wunsiedel

BURKHARDT supplies DRYLINE®, wood gasifier and CHPs

Exhaust air treatment and reduced emissions are good for the environment

Around 17,000 t of local sewage sludge (25% DR) will be dried in the course of approx. 8,000 operating hours per year in Wunsiedel. The DRYLINE®’s drying capacity is about 4,700 t dried sludge (90% DR) per year. Six BURKHARDT wood gasifiers (6x 70 kWth) with five downstream combined heat and power plants (4 x 200 kWth, 1 x 380 kWth) are used for heat generation. The heat needs for sludge drying will be covered with a total of approx. 12,000 MWh/a.

The pre-drained sludge is delivered by truck and unloaded into one of the two drive-in silos (300 m³ each) available for intermediate buffer storage. A wheeled loader will unload the sludge and fill it into the 100 m³ feed hopper (moving floor container). The sludge will be transported from the container to the belt dryer through the screw pump by means of a hydraulic moving floor system. The sludge is spread evenly onto the top layer of the two-belt dryer by means of a dispensing head and dried by an efficient circulating air system.

The belt dryer’s exhaust air is channelled to a chemical wet scrubber. This reduces ammonia emissions. The exhaust air is cleaned of all of its contents by means of a UV photo-oxidation plant with downstream activated carbon filter and released into the environment without any odour.

Key technical data

  • Total sludge recycled (25 % DR): approx. 17,000 t/a
  • Dried sludge production (90 % DR): approx. 4,700 t/a
  • Feed hopper: 120 m³
  • Drive-in silos as intermediate buffers: 2 x 300 m³
  • Storage for dried sludge: 230 m³
  • Wood gasifier / CHP heat production at 7,500 OpHrs: approx. 12,000 MWh/a

BURKHARDT scope of supply and service

  • Overall planning
  • Building and infrastructure
  • DRYLINE® sludge belt drying, including sludge feeding
  • Ventilation technology
  • Heat supply with wood gasifiers and combined heat and power plants
  • Exhaust air treatment
  • Dry sludge handling and storage
  • Heating technology and piping
  • Electrical and mechanical assembly
  • Drying process control system

Planning support from eta Energieberatung GmbH, Pfaffenhofen a.d. Ilm

  • Obtaining permit applications as well as handling any proceedings with authorities required to simplify the approval procedure in accordance with the Federal Immission Control Act, including all process flow charts, drawings etc.
  • Creating planning documents, descriptions and calculations as well as seeking offers for necessary assessments, such as immission forecasts, stack height calculations and site-specific EIA, among others.
  • Review of energy design for typical operating modes
  • Process supervision
  • General information about eta Energieberatung GmbH:


Energy generated by means of wood gasifier for the Holenbrunn sludge dryerOutside view of sludge drying system in HolenbrunnTop view of sludge drying system in Holenbrunn

Any questions about the BURKHARDT belt dryer? Get in touch with us!

Your contact for sludge drying:

« back to the overview