| 摘要 |
Apparatus is provided for reducing the concentration of a first gas in a mixture thereof with a second gas to below a limiting maximum concentration thereof in the second gas, comprising, in combination, a pair of vessels; a chamber in each vessel for a bed of particulate friable sorbent having a preferential affinity for the first gas; an influent line for delivering influent gas to each sorbent chamber; an influent flow control valve in the influent line for directing the influent gas to the one of the chambers that is on-stream for adsorption; an effluent line for delivering effluent gas from each sorbent chamber; an effluent flow control valve in the effluent line for directing the effluent gas from the chamber that is on-stream for adsorption; the effluent valve comprising a valve chamber (5) having separate inlets (2, 3) and inlet passages (6. 7) leading thereinto, one from the effluent line from each sorbent chamber; a valve seat (11, 12) across each inlet; and a free-rolling ball (10) valve responsive to effluent line gas pressure at each inlet related to downstream pressure to displace the ball and open the inlet leading from the sorbent chamber on-stream for adsorption, and direct the ball across the other inlet leading from the sorbent chamber off-stream for adsorption and close that inlet, thereby preventing effluent gas flow through that inlet into the off-stream chamber. A bleed line (9) for effluent purge flow can be provided, bypassing the closed inlet and interconnecting the inlet passages or one inlet passage or the valve chamber with one of the effluent lines for reverse purge flow of effluent gas through that effluent line into the sorbent chamber that is off-stream for adsorption but on-stream for regeneration, to regenerate the sorbent bed with such purge flow, and this bleed line can be provided with a valve for adjusting bleed flow therethrough. |
