WWTP Mannheim
Modernization of sludge drying
Engineering services
Engineering structures, LPH 1-9
Technical equipment, LPH 1-9
Structural engineering, LPH 1-6
Special services
- electrical engineering inventory
- local construction supervision
Client
Stadtentwässerung Mannheim
Karl-Imhoff-Str. 50
68307 Mannheim
Contractual relationship
Consortium
Processing period
Planning: 2014 - 2019
Construction: 2019 - 2023
Contact
Dr.-Ing. Tankred Börner
Project Management
T +49 61 51 85 95-10
t.boerner@dahlem-ingenieure.de
Short description
The sludge treatment process at the Mannheim wastewater treatment plant consisted of sludge digestion, dewatering, drying, and sludge gasification (out of service). Due to its age, the existing sewage sludge drying plant (drum dryer) was becoming increasingly prone to malfunctions and was also energy-inefficient. Therefore, the sludge drying system was to be replaced.
Three drying lines, each with a capacity of 1.50 Mg H₂O/h, were installed, for which the existing drying building was expanded. The new drying plant operates using low-temperature heat from the existing CHP units. The existing hot gas generators are no longer needed. The resulting exhaust air undergoes two-stage chemical cleaning and is then passed through a biofilter.
To maintain drying operations with at least two old/new lines, the three new lines were installed sequentially over a period of four years.
The sludge treatment process at the Mannheim wastewater treatment plant consisted of sludge digestion, dewatering, drying, and sludge gasification (out of service). Due to its age, the existing sewage sludge drying plant (drum dryer) was becoming increasingly prone to malfunctions and was also energy-inefficient. Therefore, the sludge drying system was to be replaced.
Three drying lines, each with a capacity of 1.50 Mg H₂O/h, were installed, for which the existing drying building was expanded. The new drying plant operates using low-temperature heat from the existing CHP units. The existing hot gas generators are no longer needed. The resulting exhaust air undergoes two-stage chemical cleaning and is then passed through a biofilter.
To maintain drying operations with at least two old/new lines, the three new lines were installed sequentially over a period of four years.
Project data
- Expansion size of the WWTP: 725,000 PE
- Replacement of drum dryers due to susceptibility to failure and to save energy
- Evaporator capacity: 4.5 t/h
- 3-line drying as belt dryer
- Low-temperature drying at approx. 80 °C
- Use of CHP waste heat
- Integration into the existing sludge dewatering
- New construction of the low-voltage switchgear with connection to the central process control technology
- Max. connected load approx. 530 kW, max. simultaneous power requirement approx. 390 kW
- Hall extension as a steel frame hall
- Foundations with well ring foundation
- Chemical scrubbers and biofilters for exhaust air treatment
- Replacement during ongoing operation. The three new lines were installed one after the other
