GB411918A - Improvements in the methods and means for producing active charcoal or for re-activating spent charcoal - Google Patents

Abstract

<PICT:0411918/III/1> In a continuous process for the activation or reactivation of carbon wherein the activatinggases and the carbonaceous material move in counter-current, the resultant gases are passed through a layer of glowing fuel so that the aqueous vapour content is converted to water gas thus increasing the calorific value of the gases. The layer of glowing fuel may be the fuel on the grate of the furnace serving to heat the exterior of the activating retorts or it may be constituted by the hot charcoal in one of the retorts. To increase the amount of water gas produced, an amount of steam in excess of that required for activation purposes is supplied together with supplementary air, and the gases from one activating retort may be passed to a number of zones in a second. In the case of a battery of retorts, these are operated in series and the gases are passed in counter-current with the carbonaceous material, except as regards the last retort through which they pass in the same direction as the material and are led to the furnace. Retorts 1 . . 4 are arranged vertically in a brick structure a through which heating gases from a furnace b pass in the direction of arrows c, baffles d being provided for this purpose. Conveyers f feed the carbon to be treated which is withdrawn at g. To the retorts 1, 2, 3 the activating-gases are supplied by a pipe h to the lower hot end and to the upper cold end of the retort 4 by a pipe h<1>. Hot gases leaving the activating zone of the retort and serve to heat and dry the material entering at the top and the moisture laden gases are conveyed by a pipe j to the lower end of the retort 2, any air necessary to maintain the temperature being introduced by a valve j<1>. From the upper end of the retort 2, the gases may be fed by a pump n to different points in the retort 3 by pipes o<1>, o<2>, o<3>, excess of gas being passed by a pipe t to the lower side of the grate b<1> of the furnace. From the upper end of the retort 3, the gases pass by a pipe p to the upper end of the retort 4 and move down with the activating-gases so as to pass through the glowing carbon at the base of the retort whereby all the moisture content is converted to water gas and conveyed to the furnace by a pipe s.