Abstract A method for drying coal. The coal, in the form of coal particles, is fed into a drying chamber where the coal is suspended in a fluidized bed while being dried in an atmosphere of steam which is at a temperature too low to release oxygen but high enough to extract sulphur from the coal particles. The temperature of the atmosphere in the fluidized bed where the drying of the coal takes place is regulated with heating coils which directly contact the coal particles while the latter are suspended in the fluidized bed, so that further drying is achieved by direct contact between the coal particles and the heating coils. The coal with its reduced sulphur and moisture content is taken in a preheated condition from the dryer and delivered to a coke oven to reduce the extent to which coal must be heated therein. Gas extracted from the dryer is treated to have water condensed therefrom and to extract sulphur therefrom. In addition, pellets of calcium oxide and/or magnesium oxide are delivered to the fluidized bed together with the coal particles for further extracting sulphur from the atmosphere in the fluidized bed, these pellets also being subsequently treated, as by roasting, to extract sulphur therefrom.
In a coal-drying method, feeding coal particles which are to be dried to a drying chamber, drying the coal in said chamber with heating coils supplied with steam, heating the latter steam in the heating coils with a heat exchanger while deriving heat for the heat exchanger from coke-cooling gas used during dry-quenching of coke from a coke oven, feeding to the drying chamber simultaneously with the coal particles pellets which have a composition which will extract sulphur from the atmosphere in the drying chamber, the pellets being selected from the group consisting of calcium oxide and magnesium oxide.
Claim 2
Dependent Claim
184 words
In a coal-drying method, feeding coal particles which are to be dried to a drying chamber, drying the coal in said chamber with heating coils supplied with steam, heating the latter steam in the heating coils with a heat exchanger while deriving heat for the heat exchanger from coke-cooling gas used during dry-quenching of coke from a coke oven, the coal particles having a size on the order of 1/8 inch, maintaining the drying steam in the form of a fluidized bed in a temperature range of 100*-250*C, controlling the temperature in the drying chamber with heating coils having therein steam at a temperature range of approximately 250*-450*C, utilizing for the coils pipes of approximately 2 feet diameter and forming parts of partitions which define between themselves spaces in the fluidized bed having a width on the order of 4 inches, feeding to the fluidized bed pellets selected from the group consisting of calcium oxide and magnesium oxide and having a diameter on the order of 1/2 inch, discharging the pellets and the dry coal from the drying chamber, and then roasting the pellets.
Claim 3
Dependent Claim
80 words
In a coal-drying method, feeding coal particles wHich are to be dried to a drying chamber, drying the coal in said chamber with heating coils supplied with steam, heating the latter steam in the heating coils with a heat exchanger while deriving heat for the heat exchanger from coke-cooling gas used during dry-quenching of coke from a coke oven, extracting fluid from the drying chamber, condensing water therefrom, and utilizing said water for quenching gas issuing from a coke oven.