Patent GB-227309-A (GB)
Title: Improved process of and apparatus for separating a gas from a mixture of gases
IPC: B01D53/08
Filed: 1924-03-11
Abstract: 227,309. Wade, H., (Silica Gel Corporation). March 11, 1924. Gases, separating mixtures of.-A gas is separated from a gaseous mixture by means of pulverized adsorbing material, which is continuously injected into the gas stream so as to be carried along by it, separated from the gas stream, reactivated, and returned into the gas stream for re-use. One form of apparatus is shown in Fig. 3, in which a stream of gas drawn through a conduit 12 and chamber 11 by an adjustable fan 13 is treated with pulverized adsorbing material introduced by a conveyer 15; the chamber 11 is preferablv provided with a cooling coil 22 which acts also as a baffle. The gas carrying the adsorbent in suspension passes to a continuous separator 26, from which the unadsorbed gas passes out by way of a bag-separator 27<a> and a conduit 27 while the adsorbent charged with adsorbed gas falls down a pipe 29 into a hopper 56. To prevent the passage of gas through the pipe 29, a plate 85 is fixed immediately below its lower end, this plate being oscillated in a horizontal plane by mechanism comprising a rotating disc 92 carrying a crank pin 91 to which is attached a link 90 connected at its other end to a shaft 86 on which the plate 85 is mounted. The plate 85 is balanced by a weight 88, and the extent of oscillation is such that the. end of the pipe 29 is never uncovered. The charged adsorbent on reaching the hopper 56 is fed by a conveyer 31 into an activator comprising a rotating cylinder 33 having heating tubes 34 through which hot gases from a furnace 39 are. drav-n by a fan 41. The pulverized adsorbent is drawn through the activator by a blower 43 together with a small quantity of air or steam drawn in through a valve 33a. The stream of liberated gases, air or steam, and adsorbent passes by way of a pipe 43<a> to a separator 45, from which the gases pass through a bag-separator 47 to a condenser 48 or to the atmosphere. The reactivated adsorbent falls down a pipe 46 into a hopper 16 in which it is cooled by a coil 51 and from which it is returned by the conveyer 15 into the gas stream. The lower end of the pipe 46 is sealed by a device similar to that employed in conjunction with the pipe 29. To prevent the intake of an excessive amount of air or steam by way of the valve 33a, a pipe 50 is provided along which part of the gases separated in the separator 45 is drawn by the blower 43. A number of adsorbing units of the kind described may be arranged in series in conjunction with a single activator, the feed of the adsorbent from unit to unit being in the opposite direction to that of the passage of the gases. One such series is described in which each adsorbing unit has a fan corresponding to the fan 13, but in a simpler modification, as shown in Fig. 1, the flow of gas through the series of adsorbers is effected by a single blower. This blower 209 forces the gaseous mixture along a conduit 212 into a chamber 211 into which adsorbent is fed from a pipe 217. As in the single apparatus previously described, the mixture of gases and adsorbent passes to a separator 226 from which the unadsorbed gases pass by way of a pipe 201 to a second adsorbing chamber 211<2> supplied with adsorbent through a pipe 217<2>. Thence the gases carrying adsorbent in suspension pass to a second separator 226<2> and, by way of a pipe 201<2>, to a third adsorbing chamber 211<3> supplied with adsorbent through a pipe 217<3>. From the chamber 211<3> the mixture of gases and adsorbent passes to a third separator 226<3>, from which the unadsorbed gas passes out through a bagseparator 247 and pipe 202. The adsorbent separated in the separator 226 falls down a pipe 229 to a conveyer 231 which feeds it to an activator 233. Flow of gas down the pipe 229 is prevented by causing the conveyer 231 to feed the adsorbent to an inclined pipe 232 along which the conveyer-worm does not extend. The pipe 232 is thus kept filled with adsorbent, which prevents the passage of gas. The activator 233 is slightly inclined so that the adsorbent passes to a settling chamber 234 from which the ga.s liberated in the activator passes through a pipe 251 to a condenser 48 while the adsorbent is fed by a conveyer 235a into a pipe 237. A blower 238 forces the adsorbent along the pipe 237 to a separator 226<4> from which gas passes out through a bag-separator 247<2> and pipe 253 and from whicn the adsorbent falls down a pipe 229<3> into the pipe 217<3> supplying the third adsorbing chamber 211<3>. The newly reactivated adsorbent is thus brought into contact with previously treated gas. From the vessel 211<3> the adsorbent is fed in turn through the vessels 211<2>, 211 and is finally passed again to the activator. As in the form first described, a pipe 250 is provided to return part of the gas separated in the separator 226<4> to the blower 238. The pipes 229<1> - - 229<3> are sealed against the passage of gas in the same way as the pipe 229. A modified method of sealing is described in which, as shown in Fig. 6, the adsorbent is fed along a pipe 315, having an outlet 316 in its upper side, by a conveyer 315a which does not extend along the whole length of the pipe. the end of the pipe is thus kept filled with adsorbent, which prevents the passage of gas. The process may be applied to the removal of moisture from air or other gases, and to the recoverv of sulphur dioxide, ether, acetone, benzol, gasoline, and the like from mixtures with air or other gases. The adsorbent material is preferably silica gel, but other adsorbents having pores of comparable size, such as activated carbon, gels derived from two or more colloidal oxides, or gels of tin, tungsten, aluminium, thorium, and iron, may also be employed. Specification 137,284 is referred to.