JPH0549697A - Psa type oxygen concentrator for medical use - Google Patents

Abstract

PURPOSE:To allow the stable control of the humidification of gaseous oxygen up to the relative humidity without replenishing water and to prevent frost condensation by passing a part of the dry air on the primary side outlet of one dehumidifying device via a throttle valve as a purging gas to the secondary side inlet thereof and taking out the gaseous oxygen out of the secondary side outlet of the other dehumidifying device. CONSTITUTION:Compressed raw material air is directly supplied to respective supply ports 6, 7 of two sets of the dehumidifying devices 4, 5 using moisture separating membranes 30, 31 as diaphragms. The outlet 9 of the dehumidifying device 5 is connected via the throttle valve 13 to the outlet 8 of the dehumidifying device 4 and the raw material air past the dehumidifying devices, 4, 5 is supplied to adsorption cylinders 19, 20. Gaseous nitrogen is then separated therefrom to generate the gaseous oxygen which is supplied to the secondary side inlet 11 of the dehumidifying device 5. The gaseous oxygen is taken out of the secondary side outlet 15. The dry air from the outlet 8 of the dehumidifying device 4 is partly passed as a purging gas to the secondary side inlet 10 via a throttling valve 12. Then, the stable dehumidification of the raw material air is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical PSA oxygen concentrator.

[0002]

2. Description of the Related Art Moisture contained in the raw material air of a pressure fluctuation adsorption type (PSA type) oxygen concentrator using a conventional adsorbent is adsorbed by the adsorbent to reduce the amount of gas adsorbed and at the same time diffuse gas. Since it also reduces the speed, it is desirable to remove it as much as possible. As the method, there were a cooling method and a method of dividing the adsorption cylinder into two layers, filling the first layer with alumina or silica gel, and removing it. Further, a method of dehumidifying a water separation membrane in JP-A-2-99113 is a known technique.

In the cooling method, since the refrigerator is operated, electricity is consumed as energy and there is a device having a movable mechanism, so that the failure rate is high. In addition, the method of filling extra silica gel or alumina in the adsorption column requires a larger device.

The technique disclosed in Japanese Patent Laid-Open No. 2-99113 is a new technique, and the regeneration purge gas of the PSA type oxygen concentrator is flown to the secondary side of the dehumidifier using the water separation membrane to dehumidify the raw material air. Although it is a method, the exhaust gas of the PSA oxygen concentrator temporarily flows through the secondary side of the dehumidifier, and the amount thereof is small with only the regenerated purge gas flowing subsequently,
It may be insufficient to dehumidify the raw material air that flows on average. In addition, the concentrated oxygen gas obtained by the PSA oxygen concentrator using an adsorbent is a very dry gas, and when inhaled and used for respiratory therapy, the nasal cavity becomes dry, so it is necessary to humidify the relative humidity to about 50 to 90%. There is. Conventional humidifiers employ a method of aerating oxygen gas into the water in a container containing water.

Further, the humidified oxygen gas is led to the nose of a person and flows up to the nostrils of a person, but the hose extending over several meters thereof becomes cold on the way and the moisture in the oxygen gas is condensed to form water drops on the hose. In other words, oxygen gas may not flow or water may jump out into the nose, so it is necessary to control the humidification state. However, no good method has been found so far. A fine hole is opened in the water surface of the pipe that feeds air into the water of the humidifier, a part of the dry oxygen gas is diverted, and this is mixed with the aerated oxygen gas to cut and try the diameter of the fine hole. The humidity was controlled by adjusting the method.

[0006]

When the feed air of the PSA oxygen concentrator is dehumidified, according to the method of Japanese Patent Laid-Open No. 2-99113, the PSA oxygen concentrator is provided on the secondary side of the dehumidifier using the water separation membrane. With the method of flowing the regeneration purge gas of the apparatus, the amount thereof is small and it may not be possible to uniformly and sufficiently dehumidify the raw material air. In addition, when humidifying the oxygen gas produced by the PSA oxygen concentrator, when using a conventional water container type humidifier, the water must be supplemented with distilled water every day. If it is not kept clean, problems such as bacteria and mold breeding and becoming unsanitary, and the aeration holes becoming clogged due to the mold and the like occur.

Most of these problems can be solved by the technique disclosed in JP-A-2-99113. However, JP-A-2-99
In the method of 113, the temperature and relative humidity differ depending on the season, and the pressure of the raw material air in the medical PSA oxygen concentrator is about ² kgf / cm ² · G at most and 1 kgf is the smallest.
/ Cm ² · G, the temperature inside the equipment may be as high as about 40 ° C in the winter when the air dries, and the humidity of the raw material air may be below the dew point. Since the moisture content of the purge gas is determined by the moisture that has permeated from the air to the exhaust purge gas side of the secondary side, the relative humidity becomes even lower. Since moisture is supplied from the purge gas to the oxygen gas through the moisture separation membrane, the oxygen gas is further lowered, so that the fluctuation is large and the degree of adjustment by the control valve is large.

The adjustment of the humidification of oxygen gas according to Japanese Patent Laid-Open No. 2-99113 creates a flow rate flowing through a dehumidifying device for humidification and a partial flow that flows in a partially dried state, and after humidification, they are combined into one and mixed. I take the method of adjusting. As described above, in this method, the fluctuation of water content obtained by the dehumidifier becomes large, and therefore it is difficult to always obtain a constant relative humidity by uniquely determining the amounts of the main stream and the split stream.

On the other hand, the amount of oxygen gas used by a patient varies from person to person and varies from 0.5 liters / minute to 5 liters / minute. The amount of water provided by the dehumidifier also changes depending on the amount of oxygen gas flowing. Condensation in the pipe is directly affected by the relative humidity of the flowing gas. Therefore, it is desirable to obtain relative humidity that is not affected by the oxygen flow rate used by the patient.

[0010]

Means for Solving the Problems (1) The raw material air compressed in a PSA oxygen concentrator for medical use is directly supplied to the primary inlets of two sets of dehumidifiers having a water separation membrane as a diaphragm. At the outlet on the secondary side, the dehumidifying device is connected to a pipe from the outlet on the primary side of the other dehumidifier through a throttle valve 13,
The raw material air that has passed through the pair of dehumidifiers is supplied to the adsorption column to separate the nitrogen gas and generate oxygen gas.
To the secondary side inlet 11 of the dehumidifying device 4, and a part of the dry air at the primary side outlet of the dehumidifying device 4 is made to flow as a purge gas to the secondary side inlet of the dehumidifying device 4 provided with a throttle valve 12, and the dehumidifying device 5 The oxygen gas was taken out from the outlet on the secondary side.

(2) Dehumidifying device 5 having a water separation membrane as a diaphragm
Part of the raw material air is supplied to the primary side inlet of the dehumidifier 5
A throttle valve 13 whose flow rate can be adjusted is attached to the primary outlet 9 of the dehumidifier 5, and oxygen gas is allowed to pass through the secondary inlet of the dehumidifier 5 to humidify the oxygen gas.
By adjusting the flow rate of the raw material air on the primary side of the dehumidifier 5 in 3, the humidification of the oxygen gas is adjusted.

(3) In the method of humidifying by supplying a part of the raw material gas to the dehumidifying device 5 and flowing an oxygen gas, which is a product gas of the PSA type oxygen concentrator, to the secondary side inlet of the dehumidifying device 5 for humidification. Switchable throttle valve for limiting oxygen gas flow rate 1
4 and the throttle valve 13, which is a raw material gas flow rate restricting orifice, are interlocked with each other to keep the relative humidity constant even when the oxygen gas flow rate is changed. When the amount is large, the raw material air is also increased.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. The suction port of the compressor 3 is connected to the suction filter 1 by the pipe 2, and the air is taken in and supplied as compressed raw material air to the primary side of the membrane surfaces of the dehumidifiers 4 and 5 having the moisture separation membranes 30 and 31 as the diaphragms. Mouth 6 and 7
The compressed raw material air supplied further is taken out from the gas outlets 8 and 9, and the outlet 9 of the dehumidifying device 5 is combined with the outlet 8 through the throttle valve 13 and merges to pass through the switching valve 40 so that the PSA oxygen concentrator The suction cylinders 19 or 20 are connected to the suction pipes 19 and 20 by the pipes 17 and 18, and the air is sent.

At the inlet 10 on the secondary side of the film surface of the dehumidifier 4, a part of the dry gas is discharged from the outlet 8 as a purge gas while being restricted by the throttle valve 12 (orifice) (about 12.5% to 20%). The moisture of the raw material air is taken out and sent out to the atmosphere through the outlet 41.

The adsorption cylinders 19 and 20 are connected to an oxygen tank 25 by a pipe 21 and an orifice 23 and a pipe 22 and an orifice 24, and nitrogen gas or the like is adsorbed and removed by zeolite which is an adsorbent in the adsorption cylinder, so that the oxygen gas is removed. It is concentrated and accumulated.

A pressure reducing valve 27 is connected to the outlet pipe 26 of the oxygen tank 25, and the discharge pressure is 0.2 to 0.3 kgf / cm ^2.
-Depressurized to G, adjusted to the flow rate required for each patient by the throttle valve 14 which is a flow meter, connected to the inlet 11 on the secondary side of the dehumidifier 5 and supplied to the primary side by the time it exits the outlet 15. The humidity of the raw material air is humidified through the moisture separation membrane 31. The throttle valve 14, which is a flow meter, is of a type that switches the orifice hole to switch the flow rate stepwise.
A patient who needs a large amount of oxygen gas needs a large amount of water to obtain the same relative humidity. Therefore, the amount of raw material air on the primary side also inevitably increases.

For this reason, the throttle valve 13 is also an orifice type, and in conjunction with the throttle valve 14 which is a flow meter of oxygen, the flow limiting orifice of the dehumidifier 5 is also switched at the same time, so that the primary side and the secondary side of the dehumidifier 5 can be changed. Balance the side flow rate to keep the relative humidity constant.

When the pressurized raw material air is used for the primary side of the dehumidifier 5, it is a gas with a relative humidity of almost 100%, while the oxygen gas on the secondary side has a dew point of -40 ° C or lower. Since it is a dry gas, it is possible to quantitatively determine the amount of the primary gas with respect to the amount of the secondary gas and determine the flow rate.

Further, if the relative humidity of the humidified oxygen gas is too high, dew condensation will occur in the pipe as described above, so a relative humidity of around 60% is preferable. Set the orifice diameter to obtain the required flow rate. It should be noted that it is better to have some adjustment function due to individual differences among patients.

In this embodiment, the compressed raw material air supplied to the dewatering device 5 for humidification is returned to the main stream, but the amount of air on the primary side containing the water necessary for humidifying the oxygen gas is several liters. Since it may be small, another pressure reducing valve may be inserted in front of the throttle valve 13 and discharged to the atmosphere after the throttle valve 13.
By changing the pressure of the inserted pressure reducing valve, it is possible to change the relative humidity of oxygen gas due to individual differences and seasons, and to use it with the orifice type throttle valve 13 and the orifice type flow meter throttle valve 14. By combining it with a constant humidity control function that matches the oxygen flow rate, finer humidity control can be performed.

When the throttle valve 14 which is a flow meter is composed of a float type flow meter and a needle valve, the throttle valve 13 is a needle type throttle valve, and it is preferable to use the throttle valve 13 while adjusting it. Further, in the present embodiment, the dehumidifying device 4 has a diffusion separation type dehumidifying action, and the dehumidifying device 5 has a diffusion separating type dehumidifying action.

[0022]

EFFECT OF THE INVENTION Stable dehumidification of raw material air can be achieved. The humidification of medical oxygen gas can be controlled stably to the relative humidity without replenishing water, and the trouble of dew condensation can be released. The relative humidity does not have to be adjusted each time the flow rate of oxygen gas used is changed.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of the present invention.

[Explanation of symbols]

 1 Inhalation Filter 2 Piping 3 Compressor 4 Dehumidifying Device 5 Dehumidifying Device 6 Supply Port 7 Supply Port 8 Outlet 9 Outlet 10 Inlet 11 Inlet 12 Throttle Valve 13 Throttle Valve 14 Throttle Valve 15 Outlet 17 Piping 18 Piping 19 Adsorption Cylinder 20 Adsorption Cylinder 23 Orifice 24 Orifice 25 Oxygen tank 27 Pressure reducing valve 30 Moisture separation membrane 31 Moisture separation membrane 40 Switching valve 41 Outlet

Claims (3)

[Claims] 1. In a medical PSA oxygen concentrator, compressed raw material air is supplied to the primary side inlet of each of two sets of dehumidifiers having a water separation membrane as a diaphragm, and the primary side outlet is One of the dehumidifiers is connected via a throttle valve (13) to the pipe exiting from the primary side outlet, and the feed air that has passed through these two or one set of dehumidifiers is supplied to the adsorption cylinder to remove nitrogen gas and the like. The separated oxygen gas is generated and supplied to the secondary side inlet (11) of the dehumidifying device (5), and a part of the dry air at the primary side outlet of the dehumidifying device (4) is turned on by the throttle valve (12). A PSA oxygen concentrator for medical use, characterized in that the dehumidifying device (4) is provided with a secondary side inlet that is made to flow as a purge gas, and the oxygen gas is taken out from the secondary side outlet of the dehumidifying device (5). 2. A dehumidifying device (5) having a water separation membrane as a diaphragm.
A raw material air containing moisture is supplied to the primary side inlet of the dehumidifier, and a throttle valve (13) capable of adjusting the flow rate of the raw material air is attached to the primary side outlet (9) of the dehumidifier (5). When oxygen gas is passed through the secondary inlet of the dehumidifier (5) and the oxygen gas is humidified, the flow rate of the raw material air on the primary side of the dehumidifier (5) is adjusted by the throttle valve (13). The PSA type oxygen concentrator for medical use according to claim 1, wherein the humidity of the oxygen gas is adjusted by controlling the oxygen concentration. 3. Oxygen gas by interlockingly switching an orifice switching type throttle valve for limiting the flow rate of oxygen gas (14) and an orifice switching type throttle valve for limiting the flow rate of raw material air (13). 3. The relative humidity of the oxygen gas can be controlled with respect to changes in the flow rate of the oxygen gas.
The medical PSA oxygen concentrator described.