Head of Project Sales
A new power and heat plant in Nancy, France will convert replaced railway sleepers and other surrounding wood waste into energy for hundreds of thousands of homes. The 65MWth / 14.6 MWe biomass-fired grate type boiler replaced two coal-fired boilers. Our long-term partner once again chose Laitex as a supplier of ash handling systems.
Laitex’s supply included wet and dry ash handling. Wet ash handling is used for bottom ash, while dry ash handling is used for fly ash and flue gases. In addition, Laitex was responsible for the design of the fly ash silo and its unloading systems into the truck. Erection supervision and cold and hot commissioning guaranteed seamless implementation of the system.
A 24.8 meter long wet ash conveyor runs under the grate boiler, into which the bottom ash of the boiler settles. The water inside the conveyor cools the bottom ash, after which the ash is conveyed to the ash storage. Due to the steep angle of the conveyor, excess water drains away and the conveyor collects only ash.
The dry ash handling system deals with the larger particles of ash flying from the boiler along with the flue gases. Majority of the dry ash falls down onto the cooling screw, which rapidly cools the hot ash. Some of the dry ash can be recycled back into the incineration process, while some is conveyed directly to the ash silo. In addition, it’s possible to direct the material flow to a wet ash conveyor. The solution greatly facilitates maintenance work and creates flexibility in the process.
The plant uses Bag House Filters to collect flue gases. After collecting the ash from the filters, a pneumatic conveyor sends the fly ash to the fly ash silo. From the bottom of the silo hopper, the ash is unloaded into a truck, which transports the ash for further processing.
Laitex’s strengths are especially great design skills and very robust equipment, which is especially suitable for extreme conditions such as ash handling. By being responsible for the entire ash handling process, we were able to guarantee our customer’s success.