The present invention relates to an oxygen concentrating apparatus including a cooling device for a compressor which supplies compressed air to a plurality of adsorption columns filled with an adsorbent such as zeolite.
Oxygen inhalation therapy has been employed as a most effective method of treatment for respiratory system diseases such as asthma, pulmonary emphysema or chronic bronchitis. In oxygen inhalation therapy, an oxygen concentrated gas is supplied to the patient. For this purpose, package-type oxygen concentrating apparatuses have been developed for use in the home. The package-type oxygen concentrating apparatus includes an oxygen concentrating unit for producing oxygen gas by separating nitrogen gas from the air, a compressor for supplying compressed air to the oxygen concentrating unit and a case for accommodating the oxygen concentrating unit and the compressor in order to insulate the noise. Japanese Unexamined Patent Publications (Kokai) No. 62-140619 and No. 63-218502 disclose examples of such apparatuses.
Recently, some oxygen concentrating apparatus further include a compressor housing, disposed in the case, for accommodating the compressor in order to minimize the noise emission from the apparatus. However, the compressor housing prevents the compressor, disposed therein, from being cooled.
Therefore, the objective of the invention is to provide an oxygen concentrating apparatus improved to efficiently cool the compressor disposed in the compressor housing while an increase in the weight of the apparatus is minimized.
According to the invention, there is provided an oxygen concentrating apparatus which comprises an oxygen concentrating unit, including an adsorption column filed with an adsorbent material which selectively adsorbs nitrogen gas more than oxygen gas, a compressor for supplying compressed air to the oxygen concentrating unit, a compressor housing for accommodating the compressor, the compressor housing including a plurality of air inlet ports for introducing the air into the compressor housing and an air outlet opening for discharging the air from the compressor housing, a cooling fan mounted on the compressor housing at the air outlet opening for drawing the air from the compressor housing and the air inlet ports being disposed adjacent the side wall of the compressor to direct the air flow induced by the cooling fan perpendicularly to the side wall of the compressor. The capacity of the cooling fan and the diameter of the air inlet ports are selected to ensure that a velocity of the air flow through the air inlet ports is equal to or lower than 15 m/sec.
With reference to
An oxygen concentrating apparatus 10 according to the embodiment of the invention includes an oxygen concentrating unit 12, a compressor unit 14 for supplying the compressed air to the oxygen concentrating unit 12, a tank 16 for containing the oxygen concentrated gas from the oxygen concentrating unit 12, a battery as an electric power source 18 for the oxygen concentrating unit 12 and the compressor unit 14, electric circuit boards 20 and 22 for controlling the oxygen concentrating unit 12 and the compressor unit 14, and a case 24 accommodating all of the above elements 12-22. The oxygen concentrating apparatus 10 further includes a plurality of conduits or pipes (not shown) for fluidly connecting the oxygen concentrating unit 12, the compressor unit 14 and the tank 16. The case 24 includes an air inlet opening 24a, through which the air is introduced into the case 24, and a gas outlet opening 24b through which the nitrogen gas, separated from the air by the oxygen concentrating unit 12, is exhausted.
Preferably, the oxygen concentrating unit 12 may comprise a pressure swing type gas separator. In this particular embodiment, the oxygen concentrating unit 12 includes a plurality of adsorption columns 12a filled with an adsorbent such as zeolite which selectively adsorbs nitrogen gas more than oxygen gas. The oxygen concentrating unit 12 further includes switching mechanisms 12b and 12c for sequentially selectively switching the adsorption columns to which the air is supplied from the compressor unit 14, and the adsorption columns from which the absorbed nitrogen is released, for regeneration of the adsorbent so that the respective adsorption columns repeatedly absorb nitrogen gas and release the absorbed nitrogen gas according to an absorption-regeneration cycle.
With reference to
The compressor housing 28 preferably has a configuration similar to the exterior configuration of the compressor 26 to efficiently pass the air along the surface of the compressor 26. The compressor housing 28 includes a plurality of air inlet ports 28a, an air outlet opening 28b and at least side walls facing the cylindrical side walls of the cylinders 26a and defining the inlet ports 28a. A cooling fan 30 is mounted on the compressor housing 28 at the air outlet opening 28b. In this particular embodiment, the housing 28 includes twenty-eight (28) air inlet port 28a having diameter of 6 mm. The air inlet ports 28a are disposed around the cylinders 26a to direct the air flow, induced by the cooling fan 30, through the air inlet ports 28a perpendicularly to the outer surfaces of the cylinders 26a adjacent the ends thereof where the temperature of the air in the cylinders 26a is increased by the compression of the air and the friction between the pistons and the inner surfaces of the cylinders 26a. This configuration allows the air flow to impinge against the outer surfaces of the cylinders 26a and to increase the cooling effect of the air flows. The air introduced into the compressor housing 28 through the air inlet ports 28a is exhausted into the case 24 through the air outlet opening 28b.
With reference to
In the conduit 112 between the dummy heater unit 110 and the vacuum pump 120, a valve 124 and a flowmeter 126, for controlling and measuring the flow rate of the air through the conduit 122, are provided. The experimental apparatus 100 further includes temperature sensors (not shown) for detecting the temperature difference between the outer surface of the heater unit 112 and the room temperature. When the vacuum pump 120 draws the air in the housing 114, the air flow through the nozzles 116 impinges perpendicularly on the outer surface of the heater unit 112 to cool it.
As shown in
The compressor 26 is cooled by the air induced by the cooling fan 30. The cooling air flow is selected so that the temperature difference ΔT between the temperature Ts of the outer surfaces of the cylinders 26a of the compressor 26 and the room temperature Tr is kept lower than 30° C. As is well known in the art, the higher the power of the compressor, the larger the required flow rate of the cooling air.
With reference to
As described above, the pressure loss becomes excessively high when the velocity of air flow through the nozzles 116 is higher than 15 m/sec. On the other hand, sufficient cooling of the compressor allows it to operate for long time. Further, in order to provide a large amount of cooling air, a large cooling fan is required, which will result in increase in the volume, weight, noise and power consumption of the apparatus. Therefore, in order fulfill these conditions, according to the invention, the velocity of the cooling air relative to the power of the compressor is selected to be, or to be larger than, 0.05 m/sec W, preferably in a range of 0.05 m/sec W-0.1 m/sec W. When a 100 W compressor is used, the diameter of the air inlet ports 28 is selected so that the velocity of the cooling air through the air inlet port 28 falls in a range of 5-15 m/sec and, preferably, in a range of 5-10 m/sec.
Number | Date | Country | Kind |
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2004-037831 | Feb 2004 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2005/002671 | 2/15/2005 | WO | 00 | 6/14/2006 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2005/077824 | 8/25/2005 | WO | A |
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4511377 | McCombs | Apr 1985 | A |
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Number | Date | Country |
---|---|---|
1481703 | Dec 2004 | EP |
62-140619 | Jun 1987 | JP |
62-218502 | Sep 1987 | JP |
63-218502 | Sep 1988 | JP |
2003-246607 | Sep 2003 | JP |
WO-03074113 | Sep 2003 | WO |
WO-03090903 | Nov 2003 | WO |
Number | Date | Country | |
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20070163441 A1 | Jul 2007 | US |