Energy efficient, inexpensive extraction of oxygen from ambient air for portable and home use

An apparatus for separating oxygen from air and supplying the oxygen for use at atmospheric pressure, the apparatus comprising:

• (a) a vessel for confining gases;
• (b) an ambient air input including an ambient air inlet passage leading from the atmosphere to the vessel;
• (c) a cryocooler having a cooled surface in the vessel for directly condensing oxygen from the air, the cryocooler having a control system for cooling the cold surface to a temperature greater than the boiling point temperature of nitrogen and not greater than the boiling point temperature of oxygen for condensing oxygen from air in the vessel;
• (d) a liquid/gas separator connected to the vessel to receive liquid oxygen drained from the cooled surface and separate the liquid from residual gases remaining in the vessel;
• (e) an oxygen output including an oxygen outlet passage connected to a liquid output of the separator for directing oxygen away from the vessel;
• (f) a residual gases output including a residual gas outlet passage connected to a gas output from the separator for exhausting residual gases from the vessel at substantially atmospheric pressure;
• (g) an air impeller for propelling air through the ambient air inlet passage, the residual gas passage and the vessel, the impeller developing a pressure gradient of less than 1 bar;
• (h) a heat exchanger having at least two passages separated by a gas impervious, thermally conductive wall for conducting heat from gas in a first passage to gas in a second passage, the first heat exchanger passage being connected in the air input passage and the second passage being connected in the residual gas outlet passage for transferring heat from incoming air to outgoing residual gases;
• and
• (i) a water passage connected in communication with said first passage of the heat exchanger for draining water condensed in the ambient air inlet passage, the water passage being connected to the oxygen outlet passage for returning water to outgoing oxygen gas.