Multistage air pump with adjustable inter-stage mass transfer and inter-stage sorbent cartridge

Abstract

A hand operated reciprocating multistage pump has an upstream stage and a downstream stage, each stage having a compression chamber. A regulating valve controls a mass of compressed air passing from the upstream stage to the downstream stage. By controlling the mass of compressed air passing to the downstream stage, the required force to operate the compression chamber of the downstream stage can be controlled. A sorbent cartridge can be located between the upstream stage and the downstream stage, such that the partially compressed air passes through a sorbent such as a desiccant before being compressed in the compression chamber of the downstream stage.

1 . A multistage air pump comprising:
 (a) an upstream stage having a first compression chamber pressurizing a volume of a gas to a pressure above ambient pressure;   (b) a downstream stage having a second compression chamber fluidly connected to the first compression chamber; and   (c) a regulating valve for selectively venting a portion of the pressurized gas to reduce a mass of pressurized gas passing to the second compression chamber.   
     
     
         2 . The multistage air pump of  claim 1 , wherein the second compression chamber is partly defined by a downstream stage inlet, and the downstream stage inlet includes an inlet valve. 
     
     
         3 . The multistage air pump of  claim 2 , wherein the downstream stage inlet is formed by the inlet valve. 
     
     
         4 . The multistage air pump of  claim 1 , wherein the regulating valve precludes ambient air from passing through the regulating valve into the first compression chamber. 
     
     
         5 . The multistage air pump of  claim 1 , wherein the regulating valve is moveable between a closed position precluding pressurized gas from passing from the first compression chamber through the regulating valve to an ambient pressure and an opening position permitting at least a portion of pressurized gas to pass from the first compression chamber to ambient pressure. 
     
     
         6 . The multistage air pump of  claim 1 , further comprising a transfer tube intermediate the upstream stage and the downstream stage. 
     
     
         7 . The multistage air pump of  claim 6 , further comprising a sorbent cartridge in the transfer tube. 
     
     
         8 . The multistage air pump of  claim 1 , further comprising a sorbent cartridge fluidly intermediate the upstream stage and the downstream stage. 
     
     
         9 . The multistage air pump of  claim 1 , wherein the regulating valve is fluidly connected to the second compression chamber. 
     
     
         10 . A multistage air pump, comprising:
 (a) an upstream stage having an upstream stage inlet and an upstream stage outlet, the upstream stage increasing a pressure of a gas from the upstream stage inlet to the upstream stage outlet;   (b) a downstream stage having a downstream stage inlet fluidly connected to the upstream stage outlet and a downstream stage outlet; and   (c) a regulating valve in fluid communication with at least one of the upstream stage outlet and the downstream stage inlet, the regulating valve selectively passing pressurized gas prior to the downstream stage inlet to decrease a mass of pressurized gas passing through the downstream stage inlet.   
     
     
         11 . The multistage air pump of  claim 10 , wherein the regulating valve decreases a volume of pressurized gas passing through the downstream stage inlet. 
     
     
         12 . The multistage air pump of  claim 10 , wherein the regulating valve decreases a mass of pressurized gas passing through the downstream stage inlet. 
     
     
         13 . A method of operating a multistage air pump, the method comprising:
 (a) increasing a gas pressure in a first compression chamber of an upstream stage to a first pressure; and   (b) selectively venting a portion of the pressurized gas prior to entering a second compression chamber in a downstream stage, the venting reducing a mass of pressurized gas transferred from the first compression chamber to the second compression chamber.   
     
     
         14 . The method of  claim 13 , wherein the venting occurs during each stroke of the pump. 
     
     
         15 . The method of  claim 13 , wherein the venting occurs through a regulating valve fluidly connected to the first compression chamber. 
     
     
         16 . The method of  claim 13 , wherein the pressurized gas vents from the first compression chamber. 
     
     
         17 . A multistage air pump comprising:
 (a) an upstream stage having an upstream stage piston assembly and a first compression chamber;   (b) a downstream stage fluidly connected to the upstream compression chamber, the downstream stage having a downstream stage piston assembly and a second compression chamber;   (b) a handle operably connected to the upstream stage piston assembly and the downstream stage piston assembly; and   (c) a sorbent cartridge fluidly intermediate the upstream stage and the downstream stage.   
     
     
         18 . The multistage air pump of  claim 17 , wherein the sorbent cartridge is located to pass pressurized gas from the upstream compression chamber to the downstream compression chamber. 
     
     
         19 . The multistage air pump of  claim 17 , further comprising a regulating valve selectively venting a portion of pressurized gas from the first compression chamber to reduce a mass of pressurized gas passing to the second compression chamber. 
     
     
         20 . The multistage air pump of  claim 17 , further comprising a transfer tube fluidly intermediate the upstream stage and the downstream stage, wherein the transfer tube is sized to retain the sorbent cartridge.