JP2013116217A - Oxygen concentrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxygen concentrator capable of preventing the backflow of dew condensation water to the inside of the concentrator and suitably maintaining the safety of the oxygen concentrator without using power.SOLUTION: In the oxygen concentrator 1, in a gas passage 13 between nitrogen adsorption containers 7a and 7b and an oxygen supply port 35, a check valve 53 for permitting only the inflow of atmosphere from the atmosphere side to the side of the gas passage 13 is arranged. Thus, in the case where the nitrogen adsorption containers 7a and 7b are turned to a negative pressure when the operation of the oxygen concentrator 1 is stopped, since the check valve 53 is opened and the atmosphere is introduced into the gas passage 13, the negative pressure is dissolved. That is, when a sucking action to the side of the nitrogen adsorption containers 7a and 7b is caused by the negative pressure, since the check valve 53 is opened and air flows in from the atmosphere side to the side of the gas passage 13, the backflow of the dew condensation water accumulated in a tube 39 to the inside of the concentrator is prevented.

Description

  The present invention relates to an oxygen concentrator that uses an adsorbent that preferentially adsorbs nitrogen over oxygen and supplies a high concentration of oxygen to a patient or the like by a pressure fluctuation adsorption system.

Conventionally, medical oxygen concentrators have been used for home oxygen therapy as devices that can supply oxygen-enriched gas to patients.
As an oxygen concentrator of this type, as illustrated in FIG. 6, an adsorption type oxygen concentrator in which two or plural nitrogen adsorption containers (adsorption cylinders P1) are filled with an adsorbent that preferentially adsorbs nitrogen over oxygen. Among them, a pressure fluctuation adsorption type oxygen concentrator (P3) using a compressor (P2) as an air supply means is used as a home oxygen therapy device.

  In this pressure fluctuation adsorption type oxygen concentrator, in general, air is supplied to a nitrogen adsorption container and the inside of the container is brought into a pressurized state, thereby adsorbing nitrogen in the air to the adsorbent and The oxygen adsorption gas is continuously generated by repeating the adsorption process to be taken out and the regeneration process of desorbing the adsorbed nitrogen to regenerate the adsorbent by opening the nitrogen adsorption container to the atmosphere and reducing the pressure.

  Furthermore, in order to efficiently obtain a higher concentration of oxygen, the nitrogen adsorption container is opened to the atmosphere and depressurized to desorb the adsorbed nitrogen, and a part of the product gas is used to purge the nitrogen adsorption container to regenerate the adsorbent. On the other hand, a method has been used in which the air supply means is used in reverse to exhaust air until the inside of the nitrogen adsorption container reaches a negative pressure and desorb the adsorbed nitrogen to regenerate the adsorbent.

  In this type of pressure fluctuation adsorption type oxygen concentrator, an adsorbent called synthetic zeolite is used, but nitrogen is preferentially adsorbed over oxygen and at the same time moisture is adsorbed. It becomes a state.

  Therefore, since the patient's nasal cavity is dry and uncomfortable, the oxygen concentrator is generally equipped with a humidifier (P4), and the oxygen-enriched gas humidified by passing through the humidifier. Is supplied to the patient from the oxygen supply port (P5) through the cannula (P6).

  However, when the humidified oxygen-enriched gas passes through the cannula tube connected to the oxygen supply port or the extension tube (P7) connected to the cannula, a temperature difference is generated between the oxygen concentrator and the tube. 7 (for example, the room in which the patient is present differs from the room in which the oxygen concentrator is installed, and an extension tube is pulled from the oxygen concentrator to the room in which the patient is present). Similarly, condensation may occur in the tube.

  As a result, when the oxygen concentrator is in operation, the condensed water is sent to the patient. Therefore, a water trap fixture is installed in the middle of the tube to collect the condensed water. Devices have been developed that take measures to control the humidity of the oxygen-enriched gas humidified by a vessel (see, for example, Patent Documents 1 to 4 below).

Japanese Patent Application Laid-Open No. 06-233821 JP-A-11-137692 JP 2000-135287 A JP 2006-087684 A

  However, in addition to the problems during the operation of the oxygen concentrator described above, when the oxygen concentrator is stopped, if the condensed water remains in the tube, the following problems may occur. There is.

  During operation of the oxygen concentrator, the air compressed by the compressor is sent into the nitrogen adsorption container, so the temperature inside the nitrogen adsorption container rises, but when the oxygen concentrator is stopped, the temperature inside the nitrogen adsorption container is descend. In addition, the synthetic zeolite in the nitrogen adsorption vessel has a characteristic that the amount of nitrogen adsorbed increases as the temperature decreases, so the temperature inside the nitrogen adsorption vessel decreases and the inside becomes negative pressure.

  Therefore, when condensed water droplets aggregate in the tube and become a closed state, the condensed water in the tube flows back into the apparatus by suction from the nitrogen adsorption container that has become negative pressure. As a result, the water accumulated in the apparatus (specifically, between the oxygen supply port and the humidifier) due to the backflow may become a hotbed of various bacteria. In addition, when a device such as a flow meter is disposed between the oxygen supply port and the humidifier, the device may be damaged due to the dew condensation water flowing backward.

  As a means for preventing the reverse flow of the condensed water, a method of installing a shut-off valve near the oxygen supply port of the oxygen concentrator is conceivable. Electric power is required.

  In addition, when this shut-off valve is arranged, the oxygen-enriched gas humidified by the humidifier passes through the shut-off valve, so the inside of the shut-off valve contains scale components (calcium carbonate, silica, etc.) contained in the humidifying water. As a result, the metal parts corrode due to the influence, or the scale components are deposited, which may cause the valve to malfunction.

  The present invention has been made to solve the above-mentioned problems, and its purpose is to prevent the backflow of condensed water into the apparatus without using electric power, and to improve the safety of the oxygen concentrator. The object is to provide an oxygen concentrator that can be maintained.

  (1) The present invention provides, as a first aspect, a nitrogen adsorption container filled with an adsorbent that preferentially adsorbs nitrogen over oxygen, air supply means for supplying air to the nitrogen adsorption container, and the nitrogen adsorption container. Pressurization / decompression switching means for controlling pressurization and depressurization, an oxygen supply port for supplying oxygen-enriched gas generated in the nitrogen adsorption vessel to the outside of the apparatus, and an oxygen-enriched gas from the nitrogen adsorption vessel to the oxygen supply port In the pressure fluctuation adsorption type oxygen concentrator provided with a humidifier that humidifies the oxygen-enriched gas, the oxygen-enriched gas from the nitrogen adsorption vessel to the oxygen supply port A check valve capable of inflowing air from the atmosphere side to the gas flow path side is disposed in the flow path.

  In the first aspect, a check valve (that is, the inflow of the atmosphere is permitted) that allows the inflow of air from the atmosphere side to the gas flow path side into the gas flow path of the oxygen-enriched gas from the nitrogen adsorption container to the oxygen supply port. It is equipped with a check valve that prohibits the flow of oxygen-enriched gas.

  Therefore, even when the inside of the nitrogen adsorption container becomes a negative pressure when the operation of the oxygen concentrator is stopped, because the atmosphere is introduced into the gas flow path through the check valve, the gas flow path becomes the atmospheric pressure. It is possible to prevent backflow of condensed water into the device.

  Specifically, when the tube is closed by condensed water generated in the tube connected to the oxygen supply port when the operation of the oxygen concentrator is stopped, the inside of the nitrogen adsorption container (and hence the gas flow path) becomes negative pressure. However, since the suction force that sucks the condensed water generated in the tube into the device (specifically, between the oxygen supply port and the humidifier) is not generated, the condensed water is prevented from flowing back into the device. be able to.

  As a result, the gas flow path inside the device does not become a hotbed of various bacteria due to the backflowed dew condensation water, and when a device such as a flow meter is arranged between the oxygen supply port and the humidifier , It can prevent the failure of the equipment.

  Further, in the first aspect, since the check valve is arranged as described above, it is not necessary to provide a shut-off valve on the downstream side of the humidifier, so that there is no problem due to the trouble of the shut-off valve. In addition, since a check valve that operates using a normal differential pressure is used instead of a solenoid valve, there is an advantage that power consumption of the apparatus can be saved.

  Here, the “check valve” is an on-off valve that is mechanically operated by the pressure difference between the gas flow paths on both sides divided by the check valve, and permits only one-way gas flow and vice versa. The gas flow in the direction is prohibited (here, only the inflow of the atmosphere from the atmosphere side to the gas flow path side is permitted).

  The “gas flow path of the oxygen-enriched gas from the nitrogen adsorption container to the oxygen supply port” is a gas flow path (branched gas) connected to the gas flow path and having the same pressure in the flow path. Channel).

(2) As a second aspect of the present invention, the check valve is disposed between the nitrogen adsorption container and the flow rate setting device in the gas flow path.
In the second aspect, since the check valve is arranged between the nitrogen adsorption container and the flow rate setting device, it is possible to prevent leakage of oxygen-enriched gas during operation of the apparatus.

  Since a check valve communicating with the atmosphere is arranged in the gas flow path, there is a risk of gas leakage from the check valve during operation. In the check valve, reseal pressure (pressure when the valve body begins to close and the leak amount of the valve body decreases to a specified amount) exists, but pressure higher than the reseal pressure during operation is in the gas flow path. If it is not applied, the valve body cannot be completely closed, and gas leakage occurs. Therefore, the leakage of oxygen-enriched gas can be prevented by disposing a check valve between the nitrogen adsorption container on the higher pressure side in the gas flow path and the flow rate setting device.

(3) The present invention is characterized in that as a third aspect, an outer filter for collecting foreign matters of 10 μm or more is provided on the atmosphere side of the check valve.
In the third aspect, since the outer filter that collects foreign matters of 10 μm or more is provided on the atmosphere side of the check valve, it is possible to prevent foreign matters such as dust from entering the check valve from the atmosphere side. Thereby, the malfunction of the check valve due to foreign matter biting into the check valve can be prevented.

(4) In the present invention, as a fourth aspect, an inner filter that collects foreign matters of 10 μm or more is further provided on the gas flow path side of the check valve.
Since a product tank, a decompression regulator, and the like are usually attached to the gas flow path, some foreign matter (such as a sealing material or metal chips) may be generated from the connection portion. If this foreign matter enters the check valve, the check valve may malfunction.

  On the other hand, in the fourth aspect, since an inner filter for collecting foreign matters of 10 μm or more is provided on the gas flow path side of the check valve, foreign matters are prevented from flowing from the gas flow path side to the check valve side. it can. Therefore, malfunction of the check valve can be prevented.

  In addition, the outer filter and inner filter which collect the foreign material of 10 micrometers or more mentioned above have shown the filter which has a filtration precision (absolute filtration precision) of 10 micrometers.

1 is an explanatory diagram showing a schematic configuration of an oxygen concentrator in Example 1. FIG. (A) is explanatory drawing which shows the humidifier used for the oxygen concentrator of Example 1, (b) is explanatory drawing which shows another humidifier, (c) is explanatory drawing which shows another humidifier. It is explanatory drawing which shows schematic structure of the oxygen concentration apparatus of Example 2 provided with the outer side filter which collects a foreign material. It is explanatory drawing which shows the other example which provided the outer side filter and the inner side filter in the branch gas flow path where the check valve is arrange | positioned. An experimental result is shown, (a) is a graph which shows the change of the pressure of the gas flow path of the conventional oxygen concentration apparatus, (b) is a graph which shows the change of the pressure of the gas flow path of the oxygen concentration apparatus of Example 1. . It is explanatory drawing which shows schematic structure of the conventional oxygen concentration apparatus. It is explanatory drawing which shows the state of the dew condensation water which generate | occur | produces in the tube connected to the conventional oxygen concentration apparatus.

  Embodiments of the present invention will be described below with reference to the drawings.

  In this embodiment, oxygen is concentrated by adsorbing and removing nitrogen from the air using a nitrogen adsorbent (hereinafter referred to as an adsorbent), and this oxygen-enriched gas containing high-concentration oxygen is supplied to the patient. An example is a pressure fluctuation adsorption type medical oxygen concentrator to be supplied (hereinafter referred to as an oxygen concentrator).

a) First, the configuration of the oxygen concentrator of this embodiment will be described.
As shown in FIG. 1, in the oxygen concentrator 1 of the present embodiment, the air introduction path 3 preferentially adsorbs the compressor 5 for compressing the raw material air and the nitrogen in the air from the upstream side. A pair of nitrogen adsorption containers (adsorption cylinders) 7a, 7b filled with a zeolite-based adsorbent (for example, Li-based zeolite) that separates oxygen is provided, and between the compressor 5 and the nitrogen adsorption containers 7a, 7b, Switching valves 9a, 9b, 9c, and 9d that are electromagnetic on-off valves that switch between adsorption and desorption of nitrogen by repeatedly increasing and decreasing the pressure in the nitrogen adsorption containers 7a and 7b are provided. The nitrogen adsorption containers 7a and 7b are provided with an exhaust passage 11 for exhausting nitrogen through switching valves 9c and 9d.

  Furthermore, in the gas flow path 13 on the downstream side of the pair of nitrogen adsorption containers 7a and 7b, a communication path 15 communicating between the nitrogen adsorption containers 7a and 7b, and the nitrogen adsorption containers 7a, A purge valve 17 which is an electromagnetic valve for supplying a purge gas to 7b, orifices 19a and 19b provided on both sides of the purge valve 17, a pair of check valves 21a and 21b for preventing the backflow of oxygen-enriched gas, and oxygen concentration A product tank (surge tank) 23 for storing gas, a pressure regulator (decompression regulator) 25 for adjusting the pressure of the oxygen-enriched gas, a flow rate setting unit 27 for manually setting the flow rate of the oxygen-enriched gas, and a bacteria filter 29 A humidifier 31 for humidifying the oxygen-enriched gas, a flow meter 33 for measuring the flow rate of the oxygen-enriched gas, and an oxygen supply port 35 for supplying the oxygen-enriched gas to the outside of the apparatus.A tube 39 of a cannula 37 is connected to the oxygen supply port 35.

  Among these, the flow meter 33 is disposed in the gas flow path 13 between the humidifier 31 and the oxygen supply port 35. As the flow meter 33, for example, a thermal flow sensor or an ultrasonic flow sensor is used. be able to.

  Further, the humidifier 31 gives moisture to the oxygen-enriched gas by the water vapor in the humidifier 31 because the oxygen-enriched gas that has passed through the synthetic zeolite that is the adsorbent is dry.

  As shown in FIG. 2A, the humidifier 31 includes a container 41 containing water and a lid 43 that seals the container 41. The lid 43 contains oxygen-enriched gas. An upstream pipe 47 for supplying the inside of the container 41 from the upstream side and a downstream pipe 49 for supplying the humidified oxygen-enriched gas to the downstream side are connected. In addition, in this humidifier 31, the opening end 47a of the upstream piping 47 and the opening end 49a of the downstream piping 49 are comprised so that a water surface may not be contacted.

  Returning to FIG. 1, in particular, in this embodiment, as will be described in detail later, a branch gas passage 51 is provided that branches from the gas passage 13 between the check valves 21 a and 21 b and the product tank 23. The branch gas flow path 51 is provided with a known check valve 53 that permits only the inflow of air from the atmosphere side to the gas flow path 13 side.

b) Next, the basic operation of the oxygen concentrator 1 of the present embodiment having the above-described configuration will be briefly described.
As shown in FIG. 1, in the oxygen concentrator 1 of this embodiment, oxygen concentration and adsorbent regeneration are basically performed by alternately repeating pressurization and pressure reduction in the nitrogen adsorption containers 7a and 7b.

  For example, in a state where the switching valves 9a and 9d are opened and the switching valves 9b and 9c are closed, compressed air is sent to one nitrogen adsorption container 7a by the compressor 5, and nitrogen is adsorbed by the adsorbent to concentrate oxygen. When the predetermined time has elapsed, the switching valves 9b and 9c are opened, the switching valves 9a and 9d are switched to the closed state, compressed air is supplied to the other nitrogen adsorption container 7b, and one nitrogen adsorption container 7a is connected to the atmosphere side. The adsorbed nitrogen is discharged from the exhaust passage 11 together with the reduced pressure.

  Further, when switching between pressurization and decompression, the purge valve 17 is opened for a short period of time, with respect to the other nitrogen adsorption vessel 7b that has been decompressed from the one nitrogen adsorption vessel 7a that has been pressurized. The oxygen-enriched gas is supplied in the direction opposite to the normal flow. With this oxygen-enriched gas, nitrogen and moisture adsorbed by the adsorbent in the other nitrogen adsorption vessel 7b are washed away and discharged to the outside through the switching valve 9d and the exhaust path 11.

  In this manner, only the oxygen is extracted at the time of pressurization by the nitrogen adsorption containers 7a and 7b, and the oxygen-enriched gas is supplied to the outside (and hence the patient). By repeating this alternately for both nitrogen adsorption vessels 7a and 7b, an oxygen-enriched gas having a high oxygen concentration can be obtained continuously.

c) Next, the check valve 53 which is a main part of the present embodiment will be described.
As described above, in this embodiment, the gas flow path 13 between the check valves 21 a and 21 b and the product tank 23 is provided with the branch gas flow path 51 so as to branch from the gas flow path 13. The branch gas flow path 51 is provided with a check valve 53 that permits only the inflow of air from the atmosphere side to the gas flow path 13 side.

  This check valve 53 is a valve that is mechanically actuated by the differential pressure of the flow path, and when air flows from the atmosphere side to the gas flow path 13 side (when the pressure in the gas flow path 13 is lower than the atmospheric pressure). The valve opens in the inflow direction and works so that the valve closes in the direction in which the gas flows out from the gas flow path 13 side to the atmosphere side (when the pressure in the gas flow path 13 is higher than the atmospheric pressure).

  Therefore, when the operation of the oxygen concentrator 1 is stopped, if one of the nitrogen adsorption containers 7a and 7b becomes negative pressure and the inside of the gas flow path 13 becomes negative pressure, the check valve 53 is opened. Since the atmospheric air is introduced into the gas flow path 13, the negative pressure is eliminated.

  Specifically, when the operation of the oxygen concentrator 1 is stopped, dew condensation occurs in the tube of the cannula 37 connected to the oxygen supply port 35 (or the extension tube to which the cannula 37 is connected) 39, as shown in FIG. Similarly, when the condensed water droplets aggregate so as to cover the cross section of the tube 39 (that is, when the tube 39 is closed), the inside of the nitrogen adsorption containers 7a and 7b (therefore, inside the gas flow path 13) becomes a negative pressure. When the suction action into the nitrogen adsorption containers 7a and 7b occurs, the check valve 53 is opened and air flows into the gas flow path 13 from the atmosphere side, so that the nitrogen adsorption containers 7a and 7b are opened. The inside can be prevented from becoming negative pressure. In FIG. 1, the direction in which gas is sucked is indicated by dotted arrows.

  This prevents the condensed water accumulated in the tube 39 connected to the oxygen supply port 35 from being sucked into the apparatus (specifically, the gas flow path 13 between the oxygen supply port 35 and the humidifier 31). Can do. As a result, it is possible to prevent the gas flow path 13 inside the apparatus from becoming a hotbed of germs due to the backflow of dew condensation water, and to prevent a failure of the flow meter 33 disposed between the oxygen supply port 35 and the humidifier 31. Can be prevented.

  The gas flow path 13 is provided with check valves 21a and 21b upstream from the branch gas flow path 51. However, due to the characteristics of the check valves 21a and 21b, there is a slight gas leak ( When the oxygen concentrating device 1 is stopped, particularly when the nitrogen adsorbing devices 7a and 7b are at a negative pressure), when the oxygen concentrating device 1 is stopped, the inside of the gas flow path 13 becomes a negative pressure and the condensed water is easily sucked into the device as described above. Become. Therefore, a configuration in which the check valve 53 is arranged as in this embodiment is effective.

  In particular, when the flow rate of the oxygen-enriched gas is set to be small (for example, 10% or less of the maximum flow rate), the humidity of the oxygen-enriched gas becomes high and condensation easily occurs in the tube 39. A configuration that prevents the backflow of condensed water by the check valve 53 of the example is extremely effective.

  Further, in the present embodiment, since the check valve 53 is disposed between the nitrogen adsorption containers 7a and 7b and the flow rate setting device 27, it is possible to prevent the oxygen concentrated gas from leaking during the operation of the oxygen concentrator 1.

  Since the check valve 53 communicating with the atmosphere is arranged in the branch gas flow path 51 connected to the gas flow path 13, there is a risk of gas leakage from the check valve 53 during operation. In the check valve 53, reseal pressure (pressure when the valve body starts to close and the leak amount of the valve body is reduced to a certain amount) exists, but the pressure higher than the reseal pressure during operation is the gas flow path 13. If it is not inside, the valve body cannot be completely closed, and gas leakage occurs. Therefore, by disposing the check valve 53 between the nitrogen adsorption containers 7a and 7b on the higher pressure side in the gas flow path 13 and the flow rate setting device 27, leakage of the oxygen-enriched gas can be prevented.

  Furthermore, in the present embodiment, since the check valve 53 is arranged as described above, it is not necessary to provide a shut-off valve on the downstream side of the humidifier 31, so that the trouble of the shut-off valve does not occur. Moreover, there is an advantage that the power consumption of the apparatus can be saved by using the check valve 53 that is mechanically operated by the differential pressure instead of the electromagnetic valve.

(Other variations)
As another modification, a humidifier 61 having a structure shown in FIG. 2B may be used. In the humidifier 61, the opening end 63a of the upstream pipe 63 is disposed in water, and an opening 65 for preventing water suction is formed at a position higher than the water surface of the upstream pipe 63.

  Furthermore, as another modified example, a humidifier 71 having a structure shown in FIG. 2C may be used. The humidifier 71 includes a humidifier 73 similar to that of the first embodiment, and a well-known hollow fiber humidifier 77 (which humidifies using moisture in the air) is disposed in the upstream pipe 75 of the humidifier 73. It is a thing.

  When such a humidifier 71 is used, the humidity of the oxygen-enriched gas becomes high, and condensation easily occurs in the tube 39. Therefore, the check valve 53 of the present embodiment described above is arranged to remove moisture. A configuration that prevents backflow is extremely effective.

Next, the second embodiment will be described, but the description of the same contents as the first embodiment will be omitted.
As shown in FIG. 3, the oxygen concentrator 81 of the present embodiment is similar to the first embodiment in that the compressor 83, the switching valves 85a to 85d, the nitrogen adsorption vessels 87a and 87b, the check valves 89a and 89b, the gas A flow path 91, a product tank 93, a pressure regulator 95, a flow rate setting device 97, a bacteria filter 99, a humidifier 101, a flow meter 103, an oxygen supply port 105, and the like are provided. 109 (or an extension tube to which the cannula 107 is connected) 109 is connected.

  Also in the present embodiment, the check valve 113 is connected to the branch gas flow path 111 branched from the gas flow path 91 as in the first embodiment. A filter 115 is arranged.

This outer filter 115 is a porous (porous) air filter and has a performance (filtration accuracy) that foreign matter such as dust of 10 μm or more cannot pass through.
Therefore, in this embodiment, the same effect as in the first embodiment is obtained, and the outer side filter 115 is provided in the branch gas passage 111 on the atmosphere side of the check valve 113. Intrusion into the check valve 113 can be prevented. As a result, it is possible to prevent malfunction of the check valve 113 (open / close failure, etc.) due to foreign matter biting into the check valve 113 or the like.

(Other variations)
As another modification, as shown in FIG. 4, a check valve 125 similar to that of the first embodiment is provided in the branch gas flow path 123 of the gas flow path 121, and the check valve 125 is further connected to the atmosphere side. In addition, an outer filter 127 similar to that of the second embodiment may be disposed, and an inner filter 129 having the same performance as the outer filter 127 may be disposed on the gas flow path 121 side of the check valve 125.

In this case, even when a foreign substance is generated on the gas flow path 121 side, the foreign substance can be prevented from entering the check valve 125, and thus the malfunction of the check valve 125 can be prevented.
<Experimental example>
Next, an experimental example in which it is confirmed that a negative pressure is generated in the gas flow path in the apparatus when the oxygen concentrator is stopped will be described.

  In the experiment, the conventional oxygen concentrator shown in FIG. 6 and the oxygen concentrator of Example 1 (as an example of the present invention) were used. As the oxygen concentrator, a 5 L vessel (maximum supply flow rate 5 L / min) was used, and as the configuration for humidification, the humidifier shown in FIG. 2C was used.

  Each oxygen concentrator was placed in a room at a room temperature of 35 ° C. and a humidity of 90% RH at a set flow rate of 0.5 L / min and operated overnight (12 hours). After that, the operation of each oxygen concentrator is stopped and the room is moved to a room temperature of 5 ° C. (humidity is expected). After the oxygen concentrator is stopped, the oxygen concentrator in the gas flow path between the humidifier and the oxygen supply port The change in pressure was measured. The result is shown in FIG.

As is clear from FIG. 5A, in the case of the conventional oxygen concentrator, it can be seen that the pressure in the gas flow channel has greatly decreased after the oxygen concentrator is stopped.
On the other hand, in the case of the present invention example, as shown in FIG. 5 (b), it can be seen that the pressure in the gas flow channel hardly decreases even after the oxygen concentrator is stopped.

Therefore, in the case of the example of the present invention, it is clear that there is no fear of sucking the condensed water in the tube, which is extremely preferable in terms of the safety of the apparatus.
[Relationship between Claims and Examples]
The air supply means in the present invention corresponds to the compressor of the first embodiment, and the pressure increase / decrease switching means corresponds to the switching valve of the first embodiment.

  As mentioned above, although the Example of this invention was described, this invention is not limited to the said Example, In the range which does not deviate from the summary of this invention, it is possible to implement in various aspects.

(1) For example, the number of nitrogen adsorption containers is not limited to two, and may be one or three or more nitrogen adsorption containers.
(2) The position where the check valve is provided is not limited to the position between the nitrogen adsorption container and the flow rate setting device, but the downstream side of the flow rate setting device (between the flow rate setting device and the oxygen supply port: for example, the humidifier and the oxygen supply port. Between).

  Furthermore, the position where the check valve is provided is not limited to the branch gas flow path, and may be disposed directly in the gas flow path (for example, the tubular pipe), or the check valve is connected to a product tank, for example. May be.

That is, if the atmosphere can be introduced to the gas flow path side (between the nitrogen adsorption container and the oxygen supply port), the arrangement is not particularly limited.
(3) As a performance of the outer filter or the inner filter, a filter having a performance (filtration accuracy) of collecting foreign matters having a predetermined value or more within a range of 5 to 10 μm can be adopted.

DESCRIPTION OF SYMBOLS 1, 81 ... Oxygen concentrator 5, 83 ... Compressor 7a, 7b, 87a, 87b ... Nitrogen adsorption container 9a, 9b, 9c, 9d, 85a, 85b, 85c, 85d ... Switching valve 13, 91, 121 ... Gas flow path 27, 97 ... Flow rate setting device 31, 61, 73, 101 ... Humidifier 33, 103 ... Flow meter 35, 105 ... Oxygen supply port 37, 107 ... Cannula 39, 109 ... Tube 51, 111, 123 ... Branch gas flow path 53, 113, 125 ... (introducing air) check valves 115, 127 ... outer filter 129 ... inner filter

Claims (4)

A nitrogen adsorption container filled with an adsorbent that preferentially adsorbs nitrogen over oxygen;
Air supply means for supplying air to the nitrogen adsorption container;
Pressurization and depressurization switching means for controlling pressurization and depressurization of the nitrogen adsorption container;
An oxygen supply port for supplying oxygen-enriched gas generated in the nitrogen adsorption container to the outside of the apparatus;
A humidifier disposed in a gas flow path of the oxygen-enriched gas from the nitrogen adsorption container to the oxygen supply port, and humidifies the oxygen-enriched gas;
In the pressure fluctuation adsorption type oxygen concentrator equipped with
An oxygen concentrator comprising a check valve capable of inflowing air from the atmosphere side to the gas flow path side in a gas flow path of the oxygen concentrated gas from the nitrogen adsorption container to the oxygen supply port .   2. The oxygen concentrator according to claim 1, wherein the check valve is arranged between the nitrogen adsorption container and a flow rate setting unit in the gas flow path.   The oxygen concentrator according to claim 1 or 2, wherein an outer filter that collects foreign matters of 10 µm or more is provided on the atmosphere side of the check valve.   The oxygen concentrator according to claim 3, further comprising an inner filter that collects foreign matters of 10 μm or more on the gas flow path side of the check valve.

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