Slagging in the biomass boiler: the surface determines the cleaning intervals

In a biomass boiler, ash deposits are rarely the real problem — the problem is how quickly they come back. In many plants, slagging is accepted as unavoidable. Yet the surface of the refractory lining plays a major part in determining how firmly slag and alkali deposits take hold — and therefore in determining the cleaning intervals.

Five levers from our biomass CHP projects

• A dense surface instead of porosity: a smoothly finished, monolithically compacted lining offers slag less to attack.
• Material selection according to flue gas zone: chlorine and alkalis load the hot area differently from the afterburning area — the materials are specified to suit each zone.
• Minimise joints: every joint is a potential deposit site. Prefabricated components reduce the number of joints.
• Prefabrication in Putzbrunn: critical components are cast and dried in our workshop — during the shutdown they are simply exchanged. That saves days.
• Document the cleaning intervals: whoever records when and where slag builds up plans the next overhaul instead of suffering it.