Abstract: The present invention concerns the apparatus for producing oxygen, comprising: a first zeolite bed connected to an external air pressurizing device and a depressurizing device for increasing or decreasing an internal pressure thereof; a second zeolite bed connected to the first zeolite bed in parallel and connected to the external air pressurizing device and the depressurizing device for decreasing or increasing an internal pressure thereof, the first and second zeolite beds being arranged such that the internal pressure of the second zeolite bed is decreased when the internal pressure of the first zeolite bed is increased, and the internal pressure of the second zeolite bed is increased when the internal pressure of the first zeolite bed is decreased; and a carbon molecular sieve bed communicated in fluid with the first and second zeolite beds for receiving and adsorbing oxygen produced in the first and second zeolite beds and discharging the produced oxygen to the outside and discharging selectively some of

Abstract: This invention concerns the apparatus for producing oxygen, comprising a zeolite bed system connected to an external air pressurizing means and a vacuum pump to increase or decrease the internal pressure for producing oxygen; a carbon molecular sieve bed system adsorbing oxygen generated in the zeolite bed system and supplying oxygen which is not adsorbed into the zeolite bed, and then the carbon molecular sieve bed producing oxygen by decreasing the inner pressure, it further relates the method for controlling the above apparatus, comprising; the first step of increasing the internal pressure of the zeolite bed system to adsorb nitrogen and to produce oxygen; the second step of supplying oxygen produced in the zeolite bed system to the carbon molecular sieve bed system to increase the pressure in the carbon molecular sieve bed system and to adsorb oxygen; the third step of supplying oxygen which is not adsorbed in the carbon molecular sieve bed system to the zeolite bed system; and the fourth step of decreas