JP2003180837A - Medical oxygen concentration device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize the treatment of a patient for a long period by extending the life of the adsorbent of a pressure-swing adsorption type oxygen concentration device which is a medical instrument to be used at home for the long period. <P>SOLUTION: The pressure-swing adsorption type oxygen concentration device is provided with at least one adsorption bed filled with the adsorbent capable of selectively adsorbing nitride than oxygen, an air feeding means for feeding air to the adsorption bed, a pressure increase/reduction switching means for controlling the increase/reduction of pressure of the adsorption bed, and an oxygen feeding means for feeding oxygen-enriched gas obtained from the adsorption bed to a user. The oxygen concentration device is provided with an oxygen- enriched gas storage means on the downstream side of the adsorption bed, and the pressure increase/reduction switching means controls a flow passage so as to make the oxygen-enriched gas flow from the storage means back to the adsorption bed to be purged when the operation of the oxygen concentration device is stopped. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen concentrating device which uses an adsorbent which selectively or preferentially adsorbs nitrogen over oxygen and which concentrates oxygen from the air by a pressure fluctuation adsorption method and supplies it to the user. Regarding More specifically, the purging performed by using a part of the product gas during the adsorption bed regeneration process during the steady operation of the apparatus, by supplying a large amount of purge gas to the adsorption bed during the stationary operation of the apparatus, which is larger than that during the normal operation, The present invention relates to a medical pressure fluctuation adsorption type oxygen concentrator with an improved adsorbent life.

[0002]

2. Description of the Related Art In recent years, the number of patients suffering from respiratory diseases such as asthma, emphysema, and chronic bronchitis tends to increase. One of the most effective treatment methods is oxygen inhalation therapy, Oxygen concentrators that directly separate oxygen-enriched gas from the inside have been developed, and have become increasingly popular as therapeutic devices for oxygen inhalation therapy because of convenience in use and ease of maintenance.

As such an oxygen concentrator, there is known an adsorption type oxygen concentrator in which one or a plurality of adsorbents capable of selectively adsorbing nitrogen over oxygen are filled, and among them, a compressor is used as an air supply means. The pressure fluctuation adsorption type oxygen concentrating device that has been used is used as a device for home oxygen inhalation therapy.

In the pressure fluctuation adsorption type oxygen concentrator,
Generally, air is supplied to the adsorption bed by an air compression means, and the nitrogen in the air is adsorbed by placing the bed in a pressurized state, and an adsorption step for taking out unadsorbed oxygen, and after the adsorption step, The adsorbent bed is opened to the atmosphere and decompressed to desorb adsorbed nitrogen to regenerate the adsorbent, and the adsorbent bed is purged using a part of the product gas while desorbing adsorbed nitrogen by opening the adsorbent bed to the atmosphere and depressurizing. Oxygen-enriched air is regenerated by repeating the desorption process in which the adsorbent is regenerated or the air compression means is used in reverse until the pressure inside the adsorption bed reaches a negative pressure, and the adsorbent is desorbed to regenerate the adsorbent. Is generating.

[0005]

Since such an oxygen concentrator is used for treating a patient, long-term safety and stability are strongly desired. Such an oxygen concentrator includes
Hydrophilic adsorbents such as 5A type and 13X type zeolites, or Li-substituted X type zeolites are often used, and long-term use may adsorb moisture in the atmosphere and reduce the adsorption performance of nitrogen. Are known. However, due to the limitation of installing the device in the patient's house, in order to avoid high power consumption and large size of the device, it is often the case that a function for removing moisture in the atmosphere is not installed as a pretreatment device for intake air. With long-term use, the concentration of concentrated oxygen may gradually decrease. In order to avoid this decrease in oxygen concentration, various adsorbent life extension techniques have been developed. However, a decrease in oxygen concentration is still observed.

As a measure for extending the life of the adsorbent, in addition to the function of draining and removing water in the compressed air, in addition to the oxygen enriching adsorbent on the air supply side of the adsorption bed,
Various known means have been taken such as placing an adsorbent for dehumidification. However, although any of the above-mentioned means has the effect of prolonging the life of the adsorbent by making the apparatus complicated and the life of the hygroscopic agent, it is hard to say that a complete improvement has been taken.

The present invention is intended to solve the above problems and improves the adsorbent life of a pressure swing adsorption type oxygen concentrator, which is a medical device used at home for a long time, and enables long-term treatment of a patient. It is a thing.

[0008]

Means for Solving the Problems As a result of intensive studies made by the present inventor on such a problem, all adsorbent beds were forcibly purged when the oxygen concentrator was stopped, and when the purging was completed, the device was completely removed. It has been found that the life of the adsorbent can be extended by providing the purge supply means for stopping the adsorbent.

That is, according to the present invention, at least one adsorbent bed filled with an adsorbent capable of selectively adsorbing nitrogen over oxygen, air supply means for supplying air to the adsorbent bed, and pressurization and depressurization of the adsorbent bed are provided. In a pressure fluctuation adsorption type oxygen concentrator equipped with a pressure increasing / decreasing switching means for controlling and an oxygen supplying means for supplying an oxygen concentrated gas obtained from the adsorption bed to a user, the oxygen concentrated gas of the oxygen concentration gas is provided on the downstream side of the adsorption bed. A storage means is provided, and the pressurization / depressurization switching control means is a means for controlling the flow path so that the oxygen-concentrated gas flows backward from the storage means to the adsorption bed to purge when the operation of the oxygen concentrator is stopped. A characteristic medical oxygen concentrator is provided.

Further, according to the present invention, the oxygen concentrator comprises a purging step for supplying oxygen-concentrated air generated in the adsorption bed during the desorption / regeneration step of the adsorption bed, and the pressurization / depressurization switching control means stops the operation. When the operation is stopped, the amount of purge gas supplied to the adsorbent bed during the steady operation is particularly high. The present invention provides a medical oxygen concentrator, which is 1.5 times or more and 4 times or less of a purge gas amount.

Further, the present invention is characterized in that the pressurization / depressurization switching control means is a means for performing control for closing the valves on the downstream side and exhaust opening side of all the adsorbent beds for a predetermined time after the operation is stopped. The present invention provides a medical oxygen concentrator.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A medical pressure fluctuation adsorption type oxygen concentrator of the present invention comprises at least one adsorption bed filled with an adsorbent capable of selectively or preferentially adsorbing nitrogen over oxygen, and the adsorption bed. An air supply means for supplying air to the bed, an oxygen supply means for supplying an oxygen-enriched gas obtained from the adsorption bed to a user, and a pressure increase / decrease switching control means for controlling pressure increase / decrease of the adsorption bed. In a medical pressure fluctuation adsorption type oxygen concentrator equipped with a medical device, it is possible to supply a larger amount of purge gas to the adsorption bed than in normal operation by controlling the pressurization / decompression switching control means when the oxygen concentrator is not operating. It is a pressure fluctuation adsorption type oxygen concentrator for use, and the life of the adsorbent mounted on the device is improved by the control of the pressurization / decompression switching control means
It is a device that realizes long-term treatment of patients.

Such an apparatus is provided with a pressurizing / depressurizing control control means capable of supplying an excessive amount of purge gas to the adsorption bed when the apparatus is stopped as compared with a steady operation. Specifically, it is supplied when the apparatus is stopped. This is achieved by storing the purge gas, in other words, preserving a part of the product gas as the purge gas at the time of stop. The easiest way to store the purge gas is to install a storage tank on the product gas outlet side, which is the downstream side of the adsorption bed, but it is also possible to secure the purge gas by giving the product gas flow path itself a volume. Therefore, it is possible to apply to the present invention.

As a basic control method, the air supply means is stopped when the apparatus is stopped, and the internal pressure of all the adsorption beds is released from the exhaust port. At this time, all the adsorption beds may be exhausted at the same time. In this case, the purge gas can be supplied to the adsorption bed at the same time as the exhaust, or at the same time after the exhaust, to all the adsorption beds. Also, the exhaust of the adsorption bed is
It may be performed according to a steady operation sequence. In this case, purging can be performed according to the steady operation sequence, but it is also possible to supply the purge gas simultaneously to all the adsorbent beds according to the steady operation sequence after completion of exhaust. These methods can be arbitrarily selected depending on the configuration of the air supply / exhaust pressure increase / decrease switching control means.

Since the amount of the purge gas supplied when the apparatus is stopped is supplied according to a predetermined condition, the life of the adsorbent is further improved by programming the operation sequence at the end operation in advance.

There is also a method of preliminarily filling a large amount of the adsorbent so as to avoid the use of such control so as to secure the life of the adsorption bed up to a target time, but this leads to an increase in the size of the adsorption bed. Such an apparatus leads to an increase in the air supply amount accompanying the increase in the size of the adsorption bed, leading to an increase in the size of the air supply means, that is, a deterioration in the power consumption of the apparatus. Since such a device is used at home, it is necessary to reduce the amount of power consumption from the viewpoint of reducing the economic burden on the user, and the present invention is effective in the sense of preventing the adsorbent life from being shortened at that time. Is.

The purge gas storage means used in the pressure fluctuation adsorption type medical oxygen concentrator of the present invention is not particularly limited, and tank type, flow path volume type and the like can be used. Further, such an apparatus is independent of the above-mentioned purge gas storage means, and is provided as a supply method when the purge gas is supplied from the purge gas storage means to the adsorption bed when the apparatus is stopped by the pressurization / decompression switching control means of the adsorption bed. A pressurization / depressurization switching control means for controlling the method of supplying the purge gas to the adsorption bed is included.

The pressurizing / depressurizing switching control means is not particularly limited in specific method as long as it can control the gas flow direction and timing. The on-off valve means and the like are used and can be used in the present invention.

Switching of the depressurized flow path when the apparatus is stopped is controlled according to a predetermined condition. In particular, when the rotary on-off valve means is used, it has a rotation speed monitoring means typified by a tachometer and adjusts and stabilizes the rotation speed based on the detection result of the rotation speed monitoring means. By controlling the purge gas supply amount by the rotation speed stabilizing means,
The adsorbent life is further improved.

As a basic method for improving the life of the adsorbent of the apparatus by the pressurization / depressurization switching control means, the depressurization of the adsorption bed is controlled according to a predetermined condition when the apparatus is stopped. After this,
By introducing a part of the product gas stored in advance to the adsorption bed, the water molecules that could not be completely removed during steady operation, which causes the deterioration of the adsorbent performance, are forcibly desorbed, and then the oxygen enrichment system is removed. discharge. At this time, with the same amount of purge gas as during steady operation, it may not be possible to sufficiently desorb the water molecules adsorbed on the adsorbent. It is desirable that the amount be larger than that during steady operation.

There are no special conditions for the amount of purge gas during steady operation, and normally, rather than the viewpoint of regeneration for dehumidification,
The purge gas amount is determined as a setting for obtaining a high concentration of oxygen. Generally, the purge gas amount is determined by the following empirical formula of Skarstrom's "1: 1 volume rule": supply air amount / adsorption pressure = purge gas amount / regeneration pressure.

It is preferable to purge a larger amount of oxygen when the operation is stopped than the amount of purge gas supplied to the adsorption bed in one purge step during the steady operation determined by such conditions.
Particularly, it is preferable to supply at least 1.5 times or more of the amount in order to exhibit the effect of extending the life of the adsorbent.

Further, since the apparatus stores a part of the product gas and performs the purging when the apparatus is stopped as described above,
From the viewpoint of effectively using the produced product gas and avoiding an increase in the size of the storage tank, it is desirable that the amount of purge gas when the device is stopped be kept small. However,
If the adsorbent bed is purged with the product gas for the purpose of removing the residual water content in the adsorbent, if insufficient, the residual water content in the adsorbent will not be sufficiently removed, that is, the effect of extending the life of the adsorbent will not be sufficiently expressed, and it will be the minimum necessary amount. There is a quantity. When the purge gas amount is further increased, the residual water removal amount in the adsorbent increases, but when the purge gas amount exceeds a certain value, the residual water removal amount in the adsorbent remains unchanged. Purge gas beyond this is not effective in extending the life of the adsorbent and is exhausted out of the system unnecessarily. From this point of view, the amount of purge gas when the equipment is stopped should be kept at most four times or less than the amount of purge gas supplied to the adsorption bed in one purge step during steady operation. Effective use of product gas produced and large storage tank size. It is also desirable from the viewpoint of avoiding

[0024]

EXAMPLES Specific examples of the present invention are shown below. [Embodiment 1] A behavior of a general two-cylinder bed pressure fluctuation adsorption type oxygen concentrator, which is an embodiment of the present invention, at the time of stop is shown.
FIG. 1 is an outline of the apparatus, and FIG. 2 shows a control pattern state of the apparatus.

Such an apparatus is a two-cylinder pressure fluctuation adsorption type oxygen enrichment equipped with two adsorption columns (2a, 2b) filled with Li-X type zeolite as an adsorbent for selectively adsorbing nitrogen over oxygen. Device, and solenoid valves (3a, 3b, 4
a, 4b, 5) by opening / closing control, the adsorption process of supplying the pressurized air supplied from the compressor 1, the desorption (exhaust, purge) process of exhausting adsorbed nitrogen, and the pressure equalization process are alternately switched to generate oxygen. It is a device that continuously generates. Figure 2
Shows the process of each adsorption bed and the valve open / close control status.

When the oxygen concentrator is stopped, that is, when the power supply stop signal of the oxygen concentrator is received, the compressor is stopped and the supply of the pressurized air is stopped, and the switching valve 3a for supplying the raw material from the compressor to the adsorption bed is provided. 3b
Are closed, and the valves 4a and 4b for exhausting air from the adsorption bed to the atmosphere are all opened to exhaust the pressurized gas in the adsorption bed to the atmosphere, and are stored in the product tank 7. The pressurized oxygen flows from the orifices 6a and 6b to each adsorption bed to purge the inside of the adsorption bed. The valve opening / closing time was set such that the purge gas amount was twice the purge amount during steady operation.
After the purging is completed, the exhaust valves 4a and 4b are closed and the entire apparatus is stopped.

[0027] Such a device, ambient temperature 35 ℃, ambient humidity 90%
As a result of repeating the operation and stop of the device under the high humidity environment, no decrease in oxygen concentration was observed even after 15 times as shown in FIG. It was confirmed that the life extension of the agent was achieved.

[Embodiment 2] An example in which a device similar to the device of Embodiment 1 is realized by a rotary distributor flow path switching valve (rotary valve) equipped with a commercially available electric motor will be shown. The basic configuration of the device is the same as that of the device of the first embodiment, and the electromagnetic valves (3a, 3b, 4a, 4b) for switching the flow path are realized by one rotary distributor flow switching valve 10 controlled by the inverter (11). It was done. FIG. 3 is an outline of the apparatus, and FIG. 4 shows what process the adsorption bed undergoes by the distributor flow path switching means.

When the oxygen concentrator is stopped, that is, when the power stop signal of the oxygen concentrator is received, the compressor is stopped and the supply of the pressurized air is stopped. Pressurized oxygen stored in the product tank 7 flows through the orifice 6b into one of the adsorption beds 2b to purge the inside of the adsorption bed. The rotation of the rotary distributor flow path switching valve 10 causes the other adsorption bed 2a to be purged. Exhaust and purge steps are performed in one adsorption bed, and the other adsorption bed is a holding step in which no gas flows in and out because the compressor is stopped. By repeating this process and purging the inside of each adsorption bed, the purge gas amount was set to be twice the purge amount in the steady operation. After the purging is completed, the rotation distributor flow path switching valve 10 is stopped in the middle of the flow path to close the system and stop the entire apparatus.

An apparatus having such an environment is used at an ambient temperature of 35.degree.
As a result of repeating the operation and shutdown of the device under the environment of%, it was confirmed that the oxygen concentration did not decrease and the life of the adsorbent was extended.

[0031]

The adsorption-type oxygen concentrator of the present invention improves the adsorbent life by performing purging of the adsorption bed, which is carried out during steady operation, even when the apparatus is stopped, when the apparatus is stopped, thereby improving the life of the adsorbent. Effective in treatment.

Below, the ambient temperature is 35 ° C. and the humidity is 90% RH.
In the environment of No. 2, the comparison is made with or without purging when the apparatus is stopped. As a result of supplying twice as much purge as during steady operation when the apparatus was stopped, a clear effect of extending the life of the adsorbent was recognized as compared with the case without purge.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a medical oxygen concentrator according to a first embodiment of the present invention.

FIG. 2 is a control pattern of the medical oxygen concentrator according to the first embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a medical oxygen concentrator according to a second embodiment of the present invention.

FIG. 4 is a control pattern of the medical oxygen concentrator according to the second embodiment of the present invention.

FIG. 5 is an effect of the medical oxygen concentrator of Example 1 of the present invention.

[Explanation of symbols]

1 compressor 2a adsorption cylinder 2b adsorption cylinder 3a Solenoid valve for switching feed air supply 3b Solenoid valve for switching feed air supply 4a Exhaust switching solenoid valve 4b Exhaust switching solenoid valve 5 Solenoid valve for pressure equalization 6a Orifice 6b orifice 7 product tanks 8 Regulator 9 Flow rate setting device 10 rotary distributor flow switching valve 11 inverter

Claims (4)

[Claims] 1. At least one adsorbent bed filled with an adsorbent capable of selectively adsorbing nitrogen over oxygen, an air supply means for supplying air to the adsorbent bed, and an adsorbent for controlling pressurization and depressurization of the adsorbent bed. In a pressure fluctuation adsorption type oxygen concentrator equipped with a decompression switching means and an oxygen supply means for supplying an oxygen enriched gas obtained from the adsorption bed to a user, an oxygen enriched gas storage means is provided on the downstream side of the adsorption bed. It is characterized in that the pressurization / depressurization switching control means is means for controlling the flow path so that the oxygen-enriched gas flows back from the storage means to the adsorption bed to purge when the operation of the oxygen concentrator is stopped. Medical oxygen concentrator. 2. The oxygen concentrator comprises a purge step of supplying oxygen-enriched air generated in the adsorption bed during a desorption / regeneration step of the adsorption bed, and the pressurization / depressurization switching control means is a purge gas at the time of stopping the operation. 2. The medical oxygen concentrator according to claim 1, which is a means for controlling to supply a larger amount than the purge gas amount during steady operation. 3. The medical device according to claim 2, wherein the amount of purge gas supplied to the adsorption bed when the operation is stopped is not less than 1.5 times and not more than 4 times the amount of purge gas at the time of steady operation. Oxygen concentrator. 4. The pressurization / depressurization switching control means is means for performing control for closing valves on the downstream side and exhaust opening side of all the adsorbent beds after opening for a predetermined time when the operation is stopped. The medical oxygen concentrator according to any one of 1 to 3.