Method for determining the fluidised-bed height in furnaces

摘要

It is known to provide fluidised-bed installations with downstream filters and to return the precipitated filter dust to the combustion chamber in order to maintain the required fluidised bed and to return the still unburnt ash-like residues into the furnace so as to achieve as high as possible a degree of combustion. In order to keep as high as necessary the fluidised-bed height in a fluidised-bed boiler fired with fossil fuels it is proposed, according to the invention, to suspend filter cartridges (2) in the, or touching the, boiler stack, which have filter surfaces facing the flow direction and open only on one side and which return their filter surface cakes after dedusting directly into the combustion chamber without additional conveying processes, the fluidised-bed height being determined solely by the discharge of the ash from the combustion chamber. The filter cartridges (2) are designed so as to have reinforcements which preferably at the same time have a catalytic effect for the purpose of reducing NOx. <IMAGE>