| 摘要 |
<p>2A blast furnace operation method whereby the combustion temperature can be increased even if the volatile amount of pulverized coal is no more than 25 mass% and a high pulverized coal ratio operation is being used whereby the pulverized coal ratio is at least 150 kg/t and as a result CO emissions can be reduced by: using a double piped lance (4) for blowing in fuel from a tuyere (3); blowing in the pulverized coal from the inner pipe of the double piped lance (4); blowing in oxygen from the outer pipe of the double piped lance (4); and having the oxygen concentration being at least 35 vol% for the gas comprising the carrier gas for the pulverized coal and the gas blown in from the outer pipe. In addition the oxygen concentration is less than 70 vol% when the pulverized coal ratio is at least 170 kg/t. Furthermore increased concentration of pulverized coal flow is prevented and fuel efficiency can be maintained by arranging the double piped lance (4) such that the pulverized coal flows blown in from the two pipes of the double piped lance (4) do not overlap.</p> |
