Patent GB-267369-A (GB)
Title: Improved process for the separation and recovery of gases and vapours by solid absorbents and apparatus for carrying out said process
IPC: B01D53/04
Filed: 1926-06-10
Abstract: 267,369. Godel, A. June 10, 1926. Gases, separating mixtures of.-Regeneration of a solid adsorbent such as activated charcoal is effected in two stages, the first stage consisting in heating the adsorbent, without appreciably moistening it, by means of gaseous convection currents produced in the mass, and the second stage comprising distillation of the adsorbed product by steam, superheated or not, while maintaining the convection currents if desired. The convection currents may be produced by fans, blowers, or steam injectors, and may be heated by contact with pipe coils, electric resistances, or the walls of the adsorption chamber. Subsequent cooling may also be effected by convection currents. In one form of apparatus, the adsorbent is supported by a grating B, Fig. 1, within a sheet-metal receptacle C separated by a narrow annular space from the wall of a chamber A. Near its lower end the receptacle C is grooved to form a circular channel c, which is connected by radial pipes d to the cone D of a steam injector. When the steam jet j is opened and a disc valve S raised, gas is drawn through the grating B and the charcoal &c., and forced through the pipes d, channel c, and annular space between the receptacle C and wall A to the top of the receptacle, in which is a grating B<1> above the adsorbent substance. Meanwhile the wall A is heated by hot gases passed through a jacket Q, so that the charcoal &c. is preheated by the internal circulation of gas and steam, excess of which, together with any of the adsorbed substance re-evaporated, passes through a pipe h, to a condenser. When the charcoal &c. is sufficiently hot, superheated steam is passed through it from a pipe H to the outlet h'; or steam in increased quantity, superheated or not, may be supplied by the injector jet, in which case heating is effected by the jacket Q. After steaming, the charcoal &c. is dried by the gas to be treated, or by circulating air or waste gas, which may be heated. Cooling is then effected by supplying cold water to the jacket Q and circulating gas through the adsorber. A pipe p and water-trap P drain off any condensate from the channel c. In the adsorption stage, the gas to be treated enters by the pipe H and escapes by a pipe H<1>. The heating of the wall A may be begun before the termination of the adsorption stage. In another form of apparatus, the inlet and outlet pipes for the gas treated are horizontal and parallel, the inlet communicating with an outer chamber and the outlet with the closed upper end of an inner chamber fitted at the bottom with a grating supporting the charcoal &c. Between the walls of the chambers a coil is provided, which may be used for cooling the gas. treated and for heating during circulation. A steam injector is arranged in a pipe which connects the inlet and outlet pipes outside the chambers, so that circulation may be produced through these pipes, the charcoal, the grating, and the space containing the steam coal; additional steam, superheated or not, may simultaneously be supplied by a second pipe. A similar arrangement of the steam injector S across the inlet and outlet pipes H, H<1> is shown in Fig. 5. in which, however, a central column 1 of charcoal &c., and an annular column 2, are arranged in series, and adapted for treating rich petroleum and other gases developing heat upon adsorption. These columns rest on gratings and within inner and outer bells c, c<1>, the gas to be treated passing from the pipe H around the outer bell, upward through column 2, down an annular space between the bells, and up through the column 1 to the outlet H<1>. A steam coil q or q<1> is arranged around each bell, for use during closed circulation of gas by the injector. Condensates from the two columns are drained off through pipes h<1>, h<2>. During the adsorption stage, the gas may be cooled by the coil q<1> in its passage from one column to the other. More than two columns may be similarly arranged.