GB722419A - Process and apparatus for distillation of solid material - Google Patents

Abstract

<PICT:0722419/III/1> The distillation of solids such as coal, lignite, bituminous schist, wood and other ligneous materials, is effected by passing the solid material downwardly through a retort and forcing through it a countercurrent stream of gaseous material obtained from the distillation vapours by removal therefrom of condensible products (oil, tar, &c.), the gaseous material being heated in part in an external heater and in part by passage through the hot solid product of the distillation, in order to raise it to a temperature sufficient to ensure distillation of the solid material. The hot gaseous material from the external heater may be introduced through a manifold surrounding a lower section of the retort. Cold gaseous material, moistened with water, may be introduced into the base of the retort, in order to cool the solid distillation residue discharged therefrom. The initially cool gas is thereby heated and the water converted into steam; and both assist in the distillation of the solid in the upper part of the retort. The solid is fed through feeder 10 into the top of thermally-insulated retort 1. Hot gas from manifold 13 is introduced into the retort through radial ducts at a height two-thirds from the top. Cool gas, moistened with water from reservoir 9 is introduced into the base of the retort through intake 12. The distillation vapours formed in the section of the retort above manifold 13, are discharged from the top through outlet 14. The distillation residue is cooled in the section of the retort below the manifold 13, and is then discharged from the base by mechanical unloader 11, which is provided with a water seal. The vapours from outlet 14 are passed to separator 2 (which may be a condenser, or a mechanical or electrostatic device) where the condensible components are liquefied. The liquid is discharged from the separator through siphon 15, and the remaining gas is exhausted by blower 3. Part of the gas is conveyed to heater 6 and the remainder is in part conveyed to the base of the retort and in part discharged from circulation; the proportions being controlled by valves 4, 5 and 7. The gas leaving heater 6 is passed to manifold 13. A separator 8 is provided to remove from the discharged gas those traces of condensible components not removed in separator 2. The discharged gas may be used as fuel in the combustion chamber 17 of heater 6. The pressure in the apparatus is controlled by valve 7.