摘要 |
In a coking process, coal to be coked is preheated in a cascaded whirling bed drier into which the coal is charged from above and exposed to an indirect heat transfer while whirling in a coal-steam mixture. Hot gas applied to the heating pipes in respective cascades of the drier is branched off from the total amount of hot gases discharged from a dry cooler in which hot coke from the coke oven is cooled by recirculating cooler gas constituted by a partial gas stream discharged from the cascades of the drier and reunited with the other partial stream subject to a heat exchange for generating steam. Steam from the whirling beds is discharged from the cascaded drier, separated from the entrained dust particles, and then the excessive steam is drained in a branch conduit and the remaining steam is compressed and reintroduced into the lowermost whirling bed in the drier. |