.

B. Braun Melsungen AG

Overall planning

Melsungen, Germany

Operational since 12/2014

.

The project

The PROLIGNIS GmbH & Co. KG in Ingolstadt developed the project at the Melsungen site and subsequently implemented it through the newly established company HHKW Melsungen GmbH & Co. KG. The Viessmann Deutschland GmbH was contracted by the project company to supply, install, and commission the plant equipment for the wood-fired combined heat and power plant. As a service provider for the Viessmann Deutschland GmbH, SEEGER ENGINEERING AG provided the process engineering planning, approval planning, and construction management for the plant. Construction work began in October 2013, and the installation of the plant equipment started in March 2014 at the heat and power plant. After successful installation, the warm commissioning phase began in October 2014. The first synchronization took place in mid-December 2014. Since early 2015, the B. Braun Melsungen AG has been continuously supplied with heat and steam from the new wood-fired combined heat and power plant. The generated electricity is fed into the public power grid and compensated in accordance with the EEG 2012.

The plant concept

The wood-fired combined heat and power plant utilizes renewable resources, specifically forest residual wood and landscape maintenance cuttings, as fuel. The fuel is delivered to the fuel feed hopper through a push floor system, a vibrating chute with foreign material separation, and a subsequent scraper chain conveyor. From the fuel feed hopper, the fuel is fed into the combustion grate. The combustion grate is designed as an inclined reciprocating grate. The water inside the boiler is vaporized and subsequently superheated. The ash generated on the grate is collected and discharged in a wet ash extractor. At the end of the boiler, the flue gas exits, undergoes dust removal in an electrostatic precipitator, and is emitted through a chimney. The superheated steam is expanded in a turbine, and the resulting mechanical work is converted into electricity by a generator. Steam is extracted from the turbine through controlled extraction and tapping points. The extracted steam is provided as process steam and for internal consumers. The tapped steam is used for heat supply to B. Braun Melsungen AG and for internal consumers. The steam condenses in an air condenser, and the heat is released to the ambient air.

Technical data

Firing

Grate firing with inclined reciprocating grate

Combustion heat capacity

max. 22,6 MWth

Fuel

Landscape maintenance cuttings and clearance and forest residual wood

Fuel storage

Open storage

11.700 m³

Push floors

approx. 700 m³

Steam boiler

Steam capacity

max. 24 t/h

Type

Vertical water-tube boiler

Steam temperature/pressure

485 °C/65 barabs

Turbine system

Type

Extraction-condensing turbine

Steam parameters

Inlet

64 barabs/480 °C

Controlled extraction

17 barabs/315 – 320 °C

Uncontrolled extraction

1,5 – 5 bar/150 – 250 °C

Exhaust steam

0,1 bara

Electrical power

max. 4,4 MWel

Flue gas dedusting

Dry electrostatic precipitator