Service Life Extension Technology for Coke Ovens at Nippon Steel

摘要

At Nippon Steel Corporation, 17 coke oven batteries are in operation(Tab.1). They range from coke ovens with an oven height of 5 m that were brought into operation in 1964 and have service life of over 3 7 years and those of the preheated coal charging type with an oven height of 6.5 m, which were brought into operation in 1979. In recent years, deterioration has been proceeding gradually in all these coke ovens and service life extension technology for coke ovens has become an important issue. condition by an index was established around 1980. This technique is for relatively evaluating the diagnosed age of a coke oven with respect to its calendar age and on the basis of this index Nippon Steel has worked toward the improvement and development of coke-oven inspection and repair techniques, coke-oven operation techniques, etc. Owing to the results of the above improvement and development, the service life of the coke ovens has been extended. However, the greater part of the coke ovens have now service life of more than 30 years and it has become necessary to develop new techniques because accurate repair plans cannot be formed by macroscopic diagnostic techniques and because there is a limit to on-target action for operation control.