Drycon Ash Handling System from Clyde Bergemann Senior Thermal

New 800 MW coal-fired plant in Germany receives dry bottomash handling by Clyde Bergemann

Wesel/Germany, November 2009
German-based AE&E Inova awarded the contract for a dry bottomash handling system at the new 800 MW hard coal fired Lünen powerplant, located in North Rhine Westphalia, Germany to ClydeBergemann. As an eco-friendly alternative to water, DRYCON usesfresh air to cool bottom ash while conveying. Worldwide, the wetbottom ash handling is still the predominant procedure but growingenvironmental awareness in industrialised countries and increasingwater shortage at many power plant sites are causing more andmore a shift to the dry technique.

A special advantage of DRYCON is the additional gain of heatenergy from ash by using the re-burning effect. For this purpose,Clyde Bergemann applies a hydraulic driven Jaw Type Crusher/SlideGate combination, located between the furnace and the DRYCONsystem, which crushes hot ash lumps directly where they appear.The hot cores of ash lumps got reduced to many small ones at once,falling down at the DRYCON conveyor belt where air in countercurrentflow fans the re-burning effect. This reduces the unburnedcarbon level and frees up additional thermal energy which is returnedto the steam generating process within the boiler. This arrangementincreases boiler efficiency, reduces coal usage and CO2 emissions.

Further on, compared to wet bottom ash handling, DRYCON haslower life-cycle costs and as no precious water is wasted for ashcooling and conveying, all related water treatment costs are avoided.By using dry bottom ash handling, the ash quality is ready for sale tobuilding and cement industry for re-use.

The scope of supply comprises engineering, delivery, erection andcommissioning of DRYCON, crusher plant, ash conveying system,ash silo including steel works for storage and unloading facilities aswell as supply of a control system which will be connected to thecontrol room.

The DRYCON system appeals by its rugged and modular design,both important features already being proved in numerousapplications. A particular profitably support to economical plantoperation provides the modular design. It ensures that the lengthwidthratio of the conveyor can be adjusted flexibly to the individualplant and process conditions. This guarantees efficient ash cooling atmaximum extraction rate making DRYCON to a technologicallyadvanced solution for dry bottom ash handling.

Another remarkable feature is the conveying angle based on thechain based transportation. For example, in an Asian reference, aconveyor with an angle of 40° has been realised successfully. Thisconstructive flexibility is important for both, new-builds and retrofits.

Besides DRYCON, Clyde Bergemann offers a comprehensive rangeof solutions for fly and bottom ash conveying as well as for bulkmaterialshandling. With its engineering and turn-key skills, thecompany has become a market leader. Worldwide, ClydeBergemann has built an installed base of over 500,000 MW in coalfiredpower stations.

"We are very proud of having now our first DRYCON reference inGermany. Several power plants outside Europe are already equippedwith our system. It is an enormous success for us to apply ourDRYCON solution to this high efficient power plant and it isdemonstrating our competitiveness," amends Franz Bartels,President & CEO of the Clyde Bergemann Power Group.