GB563461A - Improvements relating to the manufacture of charcoal - Google Patents

Abstract

563,461. Drying and carbonising wood. HELLER, O. Jan. 5, 1943, No. 2228/44. Divided out of 563,906, [Group IV]. [Class 34 (ii)] [Also in Group XII] In the manufacture of charcoal from wood, peat, or lignite, the material is dried prior to carbonisation by a stream of hot inert gases, such as combustion products, which are passed alternately in opposite directions through the material which is maintained at nearly but not more than 270‹ C. The wood, for example, is charged into drying columns 26, and drying gas ducts 46, 47 leading from upper and lower branches 40, 43 are brought to opposite sides of a drum 48 from which branches 73 lead by duct 78 to a mixing chamber 50 at the top of a, combustion chamber 51. Branch 74 leads to a fan 49, duct 77, and the chamber 50,. a chimney 79 exhausting surplus combustion products. By turning a baffle 75 in the drum 48 the direction of the heating gases through the columns may be reversed, and, by adjustment of valves 80, 81, a limited amount of air may be drawn through the furnace to provide inert gases. As the drying of the wood in one of the columns is completed this column is disconnected and hot combustion products are passed through it to start the carbonisation. The charcoal is discharged by opening a flap 37 at the base of the column. Each column in turn is carbonised to complete a cyclic operation. Alternatively, the dried wood may be transferred to a carbonising tower of the kind described in Specification 563,460, [Group XII]. In Fig. 4, three drying columns 26 are arranged at the top of a carbonising tower with connections to a hot gas circuit as previously described for drying the wood which is subsequently discharged from each column in turn into a carbonising chamber 1 more fully described in Specification 563,460, [Group XII]. The apparatus shown in Fig. 1 may be rendered transportable by being made in sections, the joints between which are luted with clay.