Rauchgasreinigung Flue Gas Cleaning - Hitachi Power Europe ...

Fabric Filters and Tube FiltersCleaning of dry flue gasesFabric filters and tube filters are used for dedusting dustburdened dry flue gases in thelow temperature range of up to a maximum of 250 °C. You can attain degrees of separationgreater than 99 % at pressure losses between 15 – 20 mbar; this method is especiallysuitable for dedusting fine dusts < 1 μm.Here, the dustburdened flue gases are passed through a porous tissue or felt layer, whichseparates the carrier gas from the dust particles. The dust which collects on the filter layer isremoved at defined time intervals by countercurrent flushing of the filter with air, and thendrops into the dust bunker.Systems with compressed air cleaning mechanisms are particularly widespread amongfabric filters. The individual filter tubes, which are subject to flow from outside inwards,are reinforced with filter baskets on the inside, which prevent the fabric tubes fromcollapsing.The externally deposited filter cake is removed during the ongoing operation by a rush ofcompressed air injected into the tube’s interior, briefly interrupting the flow of flue gas in therespective filter tube. The jerky inflation of the filter tube breaks off the filter cake. The purgeair, pressed through the filter in quick blasts, moreover effects a deep-cleaning of the filterfabric.The dedusting phases are optionally triggeredvia the filter element or at fixed timeintervals by a control mechanism, dependingon the pressure differential. The chamberlikeconstruction allows decoupling subsectionsfor maintenance purposes during operation.SchlauchquerschnittTube cross-section11 AbreinigungsvorgangDedusting process2 FiltrationsvorgangFiltration process3 StützkorbSupport4 FiltermediumFilter medium234Flue Gas Cleaning 19