SynopsisCoke oven operations are greatly affected by the properties of charging coal. Especially, fluctuations of moisture content of charging coal have a great adverse effect on the stable operation of coke ovens. We have always aimed at an ideal operational condition that the moisture content of charging coal is reduced and controlled economically to a constant level regardless o f weather. For this purpose, the new control technique of coal moisture using waste heat from coke ovens effectively was developed successfully. The first equipment o f ' this process came on stream at Nos. I and 2 coke oven batteries of Oita Works in September, 1983. The operation results have been better than expected.Features of this equipment are as follows:(1) This equipment is able to apply to coke oven in operation.(2) The moisture content of charging coal is controlled to 5 %.(3) The whole o f charging coal is dried.(4) In this process, the sensible heat of combustion waste gas from coke oven and of generated gas in coke oven recovered by heat exchangers using a heat carrying medium. This recovered heat is utilized at a dryer and the heat carrier is recirculated.(5) The capacity o f dryer is 260 t-dry coal/h and the moisture content of charging coal can be reduced from 11 to 5 %. Moisture content can be reduced from 9 to 5 % using only the recovered heat. For reducing from 11 to 9 %, a heating furnace is installed to heat circulating medium up.The effects of this process are a decrease in heat consumption (actual: 9093Mcal/t-dry coal, expected: 78 Meal/t-dry coal) and an improvement of coke quality (JIS DI15°-actual: 1.5, expected : 0.8), an increase of productivity (actual: 11 %, expected: 10 %).On the other hand, the carry-over to the larry car system and the ascension pipe increased. This affected adversely the gas cleaning process and the tar quality. However, these problems were not substantial and overcame by our operational improvements.This process has been operating satisfactorily.
Synopsis Nippon Steel Corporation began pulverized coal injection at No. 1 blast furnace (inner volume: 4 158 m3, top pressure: 2.5 x 104 kg/m2) at Oita Works in June, 1981. Since then, both the pulverized coal injection system and No. 1 BF have been working smoothly with no serious troubles. This report describes the development of application techniques of pulverized coal injection to a large blast furnace with high top pressure and high blast temperature, and introduces the results of operation at Oita No. 1 BF in comparison with those of oil injection and all-coke operations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.