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II. Necessity of GI-180 (stack lining material)

Why we need GI-180 lining system at this time ?

In the past when environment preservation had not been a major issue in the society, industries using fossil fuels such as thermal power plants, operated it without desulfurization facilities, using fireproof materials such as corbel-based acid resisting and fire proof bricks as lining material of chimneys to exhaust flue gas of which temperature ranges from 125 to 180 degree C. But as environment preservation has become one of major concerns in every society around the world, the desulfurization facility has been mandatorily adopted for keeping air and human health from further pollution. In this case, the exhaust gas temperature ranges from 150 to 160 degree C. and it drops down to 85 ~ 90 degree C as soon as the gas passes through the desulfurization facility and G.G.H. At this stage, strong acid gas high in temperature and rich in moisture is produced due to drastic changes in temperature of flue gas. In this connection, it requires fireproof material that has additional definite quality of acid resistance and moisture proof. But existing corbel-based acid resisting and fireproof brick liners for chimneys are apt to developing cracks from drastic temperature fluctuation in chimney structure materials and inappropriate spacing among corbels. On top of this, as insulation effect reduces generally from partial damages in lining system, concrete could develop more serious cracks, and consequently concrete structure is rapidly weakened by its neutralization and degradation from sulfur dioxide gas. All of these factors seriously influence chimney structure to shorten lifetime in service. And Bumtite C-14 has been widely used as castable mortal for steel chimneys so far. But in general, the acid resistance of the castable rapidly decreases after 10 years operation because high corrosive acid, Fe₂O₃increases from 2 to 12 % in the chimney structure. And when the desulfurization facility is additionally constructed to existing plant, complete internal environment changes in the chimney happen, and the damaged part of the existing chimney structure would degrade rapidly and significantly, curtailing the life cycle of the chimney structure. Thus, reinforcing work for the internal part of chimney must be implemented definitely. In this case, the suitable material to reinforcing work of certain chimney should withstand harsh thermal shock from abrupt and rapid temperature changes as well as severe acidic condition within the chimney. BOROSILICATE CELLULAR GLASS BLOCK is the ideal clue for such renovation and reinforcement works, one of which was carried out by KEPCO (Korea Electric Power Corporation).