Wood panel industry
2006 Energy plant for the wood panel industry
50 MW hot gas generator with integrated thermal oil heating
for Egger in Hexham (UK) & Rion (F)
After returning to Germany from South Africa, Dipl. Ing. Michael Kaden founded the Alera GmbH in 2004. This company soon was engaged in the supply of turn key energy plant, especially for the wood based panel industry. To cater for the special energy requirements of the wood panel industry, the technology employed was based on the technology introduced already in 1984 with the integration of hot gas generation and water / thermal oil heating. This system was further optimised and was introduced to the industry under the name LignoEnergy . With this system, the heating of thermal oil is directly effected through the membrane furnace wall construction. To control the hot gas heat and the thermal oil heat independently, surplus heat absorbed by the furnace wall is reintroduced into the combustion process via air preheaters.
With this system, a separate bypass thermal oil heater is not necessary and therefore the plant is compact, economic and easy to maintain. The hot gas temperature can be maintained at a high temperature over a wide range of operation conditions which results in a high efficiency for the whole process.
With this link a process schemata can be opened
Alera GmbH has supplied two turn key plant for the Austrian wood panel manufacturer Egger for their production plants in Hexham (UK) and Rion (F). The two units are identical and have the following technical data:
- Fuel: waste wood from the production, bark and sander dust.
- Firing capacity: 40 MW thermal oil cooled travelling grate; and 4 x 6,5 MW dust burner.
- Total firing capacity: 50 MW
- Hot gas at 850 °C = 36 MW
- Thermal oil heating through furnace walls = 12 MW
- Heating balance control with thermal oil / air heat exchanger.
The heart of the plant is the thermal oil cooled furnace. consisting of gas tight welded membrane walls. The construction is supported by a steel frame, which also holds the thermal oil cooled travelling grate.
A specially designed, low pressure loss, hot gas cyclone cleans the flue gases at 850 °C with 99 % of all particles > 0,1 mm by only needing 2 mbar pressure loss.
The plants are equipped with "state of the art" electrical, measurement and control systems. All large motors with control function are fitted with variable speed drives. For the control of the plants a SIEMENS PLC S7 is installed and the man machine interface is effected via a Wonderware InTouch visualisation system. In this way, the energy plant can be fully operated from the main press control room and no operators are needed in the boiler house.