Apparatus for compressing and storing oxygen enriched gas

Abstract

Methods and apparatus for storing high-pressure, high-purity oxygen in a pressure vessel for use in the home health care or related fields as for ambulatory patients, persons confined to wheelchairs, and those who are bedridden. The Oxygen may be produced from air an oxygen-enriched gas and stored in a concentrator product tank. After reaching a predetermined pressure, the gas is fed to a compressor where it is compressed to a high pressure and stored in a mobile or portable high-pressure container. A patient can thus have increased mobility through use of the portable, one or more high-pressure oxygen containers.

1 . A multiple-stage gas compressor, comprising:
 a compressor having a plurality of pistons, including at least one wobble piston for compressing a gas; and   at least one cylinder piston for further compressing said pressurized gas from said at least one wobble piston.   
     
     
         2 . A multiple-stage gas compressor according to  claim 1 , wherein said wobble piston is connected to a first drive shaft, and wherein said cylinder piston is connected to a second drive shaft. 
     
     
         3 . A multiple-stage gas compressor according to  claim 2 , including an accumulator tank between said wobble piston and said cylinder piston, and wherein said first drive shaft rotates at a higher RPM than said second drive shaft. 
     
     
         4 . A multiple-stage gas compressor according to  claim 3 , wherein said compressor is operatively connected to a storage tank capable of containing oxygen enriched gas and wherein said compressor compresses said oxygen enriched gas. 
     
     
         5 . A multiple-stage gas compressor according to  claim 4 , including a bleed off valve located downstream from one of said cylinder pistons for effective noise reduction when said compressor is disengaged from said storage tank. 
     
     
         6 . A multiple-stage gas compressor according to  claim 3 , including a second cylinder piston for further compressing said gas from said first cylinder piston, and wherein said second cylinder piston is connected to said second drive shaft. 
     
     
         7 . A multiple-stage gas compressor according to  claim 6 , wherein said first and second cylinder pistons are substantially longitudinally aligned, and wherein said second drive shaft rotates at a slower rate than said first drive shaft. 
     
     
         8 . A multiple-stage gas compressor according to  claim 7 , wherein the area of the piston head of said first cylinder piston is smaller than the area of said wobble piston head, and wherein the area of said second cylinder piston head is smaller than the area of said first cylinder piston head. 
     
     
         9 . A multiple-stage gas compressor according to  claim 8 , wherein each piston head has a plurality of piston rings, and wherein said plurality of piston rings includes at least one guide ring and at least one seal ring. 
     
     
         10 . A method of providing a portable source of oxygen utilizing a home health care oxygen concentrator having a patient flow line to deliver product gas from a product tank to a patient comprising the steps of:
 setting a minimum concentration of oxygen for the product gas and measuring the oxygen concentration of the product gas to establish that the minimum is met;   setting a minimum delivery flow rate of said product gas to said patient; measuring the delivery flow rate to said patient, and if the minimum delivery flow rate and the minimum concentration are met, directing excess product gas to compressor to compress said product gas, said compressor having at least a first compression stage and a second compression stage.   
     
     
         11 . A method according to  claim 10 , wherein an excess product gas is directed to said compressor only so long as both the minimum delivery flow rate and the minimum concentration of oxygen in the product gas are met. 
     
     
         12 . A method according to  claim 11 , wherein said first compression stage precedes said second compression stage and utilizes said wobble piston. 
     
     
         13 . A method according to  claim 12 , wherein said second compression stage utilizes multiple non-wobble pistons. 
     
     
         14 . A method as set forth in  claim 10 , wherein a buffer tank contains product gas at a pressure of from about 7 to about 14 psi and the portable storage unit includes compressed product gas at a pressure of form about 500 to about 3,000 psi. 
     
     
         15 . A method as set forth in  claim 14 , wherein said first stage compresses said product gas to a pressure of from about 10 to about 60 psi. 
     
     
         16 . A method as set forth in  claim 10 , wherein said delivery flow rate is from about 0.1 to 6 liters per minute. 
     
     
         17 . A multiple-stage gas compressor containing a two-part piston assembly, comprising:
 a plurality of pistons each of which linearly reciprocates in a separate cylinder, each of said pistons having a piston head and a separate piston base connected by a piston rod, the area of a first piston base being approximately the same as the area of every other piston base, and   each piston assembly having a connecting rod connected at one end to said piston base and the other end being able to be connected to a crankshaft.   
     
     
         18 . A multiple-stage gas compressor according to  claim 17 , wherein each remaining piston head is utilized to sequentially compress a gas after it is compressed b said first piston head, and wherein each sequential piston head has a smaller area than the preceding piston head utilized for compressing the gas. 
     
     
         19 . A multiple-stage gas compressor according to  claim 18 , wherein said piston head has a plurality of piston rings. 
     
     
         20 . A multiple-stage gas compressor according to  claim 19 , wherein said plurality of piston rings includes at least one guide ring and at least one seal ring. 
     
     
         21 . A multiple-stage gas compressor according to  claim 20 , wherein said seal ring is substantially U-shaped and communicates with the gas during compression thereof.