Abstract: 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-stream 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.

Abstract: Coal is pretreated for a coking plant so that it is passed in two stages through two throughflow driers successively connected with one another, the driers are supplied with a heat carrier formed by a steam overheated to a temperature between 400.degree. and 600.degree. C., dust is removed from the steam after passing the throughflow driers, and the steam is heated after the dust removal in a heat exchange with a circulating gas of a coke dry cooler.

Abstract: 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.