NEW RUBBER LINING SYSTEMS AS CORROSION PR OTECTION IN FLUE-GAS DESULFURIZATION PLANTS

In flue gas desulfurization plants (FGD) of hard coal fired power plan ts rubber linings as corrosion protection of steel surfaces have now r eached service lives of more than 14 years while shorter service lives are expected with FGDs of lignite fired power plants with up to 25-de grees-C higher operation temperatures. Important criteria for the asse sment of the service life of rubber linings are their diffusion tightn ess to corrosive substances, their absorption of media as well as thei r resistance to mechanical damage. Several concepts to prolong the ser vice life have been described. They include the consideration of the b utyl rubber qualities IIR, CIIR, or BIIR as well as an increase in the rubber lining thickness. In FGD areas which are severaly exposed to m echanical stress, linings with ceramic bricks are provided. New soluti on proposals for FGD areas with a high partial pressure of water vapou r have been offered using a combination of a PTFE sheet or a vinyl est er resin coating together with the rubber lining.