JP2006062932A - Oxygen concentrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oxygen concentrator capable of reducing power consumption without deteriorating reliability and durability. <P>SOLUTION: In switching valves 41, 42, 51 and 52 for switching a pressurizing step of sending compressed air to nitrogen adsorbers 31 and 32 and an evacuating step of discharging a gas containing nitrogen which is sent and adsorbed to the adsorbers 31 and 32 to outside, a valve which is a pilot type solenoid valve and whose main valve is composed of a diaphragm is used. A large main valve can be opened and closed by opening and closing a small pilot valve with a low electric power since a conventional direct acting solenoid valve is not used and the pilot type solenoid valve is used. Therefore, a compressor having a small discharge quantity can be used since an effective flow passage cross section area is greatly secured and flow loss is reduced. And also, the reliability is enhanced since the diaphragm type main valve is used and a sliding part for a valve seat is eliminated and the complication of a structure is not incurred as compared with a spool type and a poppet type. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an oxygen concentrator, and more particularly to an oxygen concentrator used for oxygen inhalation therapy effective as a treatment method for diseases of respiratory organs such as chronic bronchitis.

  This type of oxygen concentrator (also referred to as an oxygen concentrator; hereinafter simply referred to as a device) separates and concentrates oxygen in the air as an oxygen concentrating method that permeates oxygen and selectively (preferentially) adsorbs nitrogen. So-called adsorption-type oxygen concentrators using adsorbents such as zeolite are widely used. This oxygen concentrator usually supplies air compressed by a compressor into a nitrogen adsorption container (adsorption cylinder) filled with an adsorbent capable of preferentially adsorbing nitrogen over oxygen, and in a pressurized state. By adsorbing nitrogen, pressurizing process (adsorption process) to obtain high oxygen concentration gas (oxygen-enriched air) and exhausting (releasing) the adsorbed nitrogen to the outside by reducing the pressure in the nitrogen adsorption container It is configured so that a high oxygen concentration gas is continuously generated (manufactured) by alternately (sequentially) performing a decompression step (regeneration step) for regenerating the adsorbent (Patent Document 1, Patent Document 2). The high pressure, high oxygen concentration gas generated in this way is sent to a tank (reservoir) that temporarily stores the gas, and the pressure and flow rate are adjusted by a regulator and a flow rate setting device, and processing such as humidification is performed. And then supplied to the patient.

  Usually, two (two) nitrogen adsorption containers in such an apparatus are provided. In this apparatus, piping for supplying compression from a compressor and piping for exhaust are connected to each nitrogen adsorption container. And when the pressurization process is performed in one container, the switching valve (two-way valve) provided in each pipe is alternately switched (open / closed) so that the decompression process is performed in the other container. It is configured as follows. That is, a high oxygen concentration gas is continuously obtained by repeatedly performing a pressurizing step and a depressurizing step in a constant time cycle.

By the way, since this type of oxygen concentrator is used continuously for a long period of time by the patient day and night (always), including during sleep, a motor for driving a compressor, etc. A considerable amount of power is consumed, including power consumption. Therefore, it is extremely important to save power so as to reduce the burden of electricity bills for patients who are at home. Patent Document 1 discloses a method of using an adsorbent having a high nitrogen adsorption capacity for power saving. Patent Document 2 proposes a technique for optimizing a time sequence for opening and closing a switching valve that switches between a pressurizing process and a depressurizing process.
Japanese Patent Laid-Open No. 9-20503 JP 2002-79030 A

  However, sufficient power saving is not achieved by the above-described means alone, and stronger power saving is demanded. Under these circumstances, the present inventor has conducted research and development on power saving from a completely different viewpoint from the above means, and switching between the pressurization step and the decompression step required in the conventional oxygen concentrator. The optimization of the selection of each switching valve for pressurization or depressurization in order to perform the process was considered to contribute to the reduction of power consumption. The reason is as follows.

  Conventionally, a direct acting (direct acting) electromagnetic valve has been used as a switching valve for performing such pressurization and decompression. This is because the direct-acting solenoid valve itself is low-cost, and when this is used, the piping and the like are simplified because the pilot piping is not necessary. However, in such a direct acting solenoid valve, a flow rate loss is large because a valve having a small effective channel cross-sectional area is used. For this reason, in the conventional oxygen concentrator, a compressor having a larger discharge amount must be used, and thus the power consumption required for driving the compressor increases, resulting in an increase in power consumption of the oxygen concentrator. I was invited. On the other hand, flow loss can be reduced by using a direct-acting solenoid valve with a large flow path cross-sectional area when the valve is opened, but a large force is required to operate the valve. This type of switching valve that consumes a large amount of electric power consumes a large amount of electric power. Therefore, it is not possible to employ a direct acting electromagnetic valve having such a large cross-sectional area of the flow path.

  Therefore, it can be proposed to use a pilot solenoid valve instead of such a direct acting solenoid valve. According to the pilot type solenoid valve, the small valve as the pilot valve is driven as the solenoid valve, and the large main valve is operated and switched by the pilot pressure (air pressure). Even if a large one is used, the power consumption required for switching the valve can be kept small. Therefore, according to this electromagnetic valve, since a thing with a large channel cross-sectional area can be used, flow loss can be reduced and the discharge flow rate of a compressor can be made small. Thus, the power consumption of the apparatus can be reduced as a result of reducing the power consumption required to drive the compressor, which is the main power consuming device in the apparatus.

  However, even if a pilot type solenoid valve is used, if the main valve is of the spool type, the movement of the spool becomes unsmooth when a minute solid matter adheres between the spool and the sleeve inner surface forming the valve body. There is a problem in reliability or durability. Since the oxygen concentrator is used by a patient for a long period of time as a therapy for a long period of time, extremely high reliability is required. Therefore, this cannot be adopted. Moreover, in the pilot type solenoid valve whose main valve is a poppet type, there is a problem that the size of the main valve is increased in order to ensure a large flow path cross-sectional area. In addition, this is also questionable in terms of reliability and durability in that the internal structure becomes complicated based on the fact that there is a sliding part (poppet shaft), etc., and it is also expensive. There is also a problem.

  The present invention has been made in view of these problems, and provides an oxygen concentrator capable of reducing power consumption without reducing the reliability or durability of a switching valve that performs pressurization or decompression. Is the purpose.

In order to achieve the above object, the present invention according to claim 1 is characterized in that a high oxygen concentration gas is supplied by supplying compressed air into a nitrogen adsorption vessel filled with an adsorbent capable of preferentially adsorbing nitrogen over oxygen. A high oxygen concentration gas is obtained by alternately and repeatedly performing a pressurizing step to obtain and a depressurizing step of regenerating the adsorbent by exhausting nitrogen adsorbed by reducing the pressure in the nitrogen adsorption vessel to the outside. A pressure fluctuation adsorption type oxygen concentrator of the type,
There are two or more nitrogen adsorption containers, and each nitrogen adsorption container is connected to a pipe for supplying compressed air from a compressed air supply source and a pipe for exhausting the adsorbed nitrogen to the outside. In each of these pipes, provided with a switching valve for switching between the pressurization step and the pressure reduction step,
At least one of the switching valves is a pilot solenoid valve, and a main valve is a diaphragm valve.

  According to a second aspect of the present invention, in the first aspect, in place of using at least one of the switching valves as a pilot solenoid valve and using a diaphragm valve as a main valve, The oxygen concentrator is characterized in that all are pilot type solenoid valves and the main valve is a diaphragm type valve. According to a third aspect of the present invention, there is provided the oxygen concentrating device according to the first or second aspect, wherein each pilot-type electromagnetic valve is manifolded.

  In the oxygen concentrator of the present invention, a pilot system is provided for a switching valve between a pressurizing step (hereinafter, also referred to as pressurization or simply pressurization) and a depressurization step (hereinafter also referred to as depressurization or simply depressurization) of the nitrogen adsorption container. Therefore, even when the power consumption is the same, it is possible to use one having a larger effective flow path cross-sectional area when the main valve is open than when a direct acting solenoid valve is used. Accordingly, since the flow loss can be reduced, the discharge flow rate of the compressor can be reduced, so that the power consumption required for driving the compressor can be reduced. As a result, power saving as the oxygen concentrator can be achieved.

  In addition, in the present invention, the main valve is a diaphragm type among the pilot-type solenoid valves as the pressurizing / depressurizing switching valve for the nitrogen adsorption container, so that the main valve is slid for the valve seat. There is no moving part. In addition, because of its structure, compared to a spool type or poppet type, the structure is not complicated, and thus reliability and durability can be improved. In addition, since the cross-sectional area of the flow path can be easily increased, the flow loss can be reduced. Thus, according to the oxygen concentrator of the present invention, it is possible to save power without reducing the reliability or durability of the switching valve for pressurization or decompression. The merit of power saving corresponds to the number of pilot type solenoid valves whose main valves are diaphragm type valves. However, as in the invention according to claim 2, all of the switching valves are provided in the switching valve. When a pilot type solenoid valve having a diaphragm type valve is used, extremely high power saving can be achieved.

  Further, as in the present invention according to claim 3, since each of the pilot type solenoid valves is made a manifold, simplification of the piping and space saving can be achieved as compared with the case where the switching valves are individually provided in the middle of each piping. (Compact) is achieved. Therefore, the connection work of piping becomes efficient and it can contribute also to the compactness of the whole oxygen concentrator. Note that the form of manifolding (manifold structure) may be a unitary manifold in which the manifold main body is integrated or may be divided into two.

  The best mode for carrying out the present invention will be described in detail with reference to FIG. 1 and FIG. FIG. 1 is a piping system (block) diagram showing a schematic configuration of an oxygen concentrator 101 according to the present invention. As shown in this circuit diagram, the oxygen concentrator 101 according to the present embodiment converts the air taken in from the air intake port 2 through the dust-proof filter 4a, the intake filter 4b, and the intake muffler 4c, which is a compressor 21 that is a compressed air supply source. The compressed air and the compressed air are connected by pressurizing pipes (pressurizing pipes) for supplying two compressed air to the nitrogen adsorption containers (adsorption cylinders) 31 and 32 arranged in parallel. Although not shown in the drawings, the nitrogen adsorption containers 31 and 32 are filled with, for example, zeolite powder as a nitrogen adsorbent that selectively adsorbs nitrogen over oxygen. A cooling fan 23, a heat exchanger 24, and a pressure sensor 25 are provided in the middle of the compressor 21, the nitrogen adsorption containers 31 and 32, and the piping.

  The pressurizing pipe is connected to the nitrogen adsorption containers 31 and 32 by branching into two pipes on the secondary side of the pressure sensor 25. In the middle of each branch pipe, pilot-type solenoid valves (two-port valves) are used as switching valves (open / close valves) 41 and 42 for pressurization to the nitrogen adsorption vessels 31 and 32, and the main valve A diaphragm type (not shown) is attached.

  Further, in the middle of the piping connecting the switching valves 41 and 42 for pressurization and the nitrogen adsorption containers 31 and 32, after the nitrogen adsorption containers 31 and 32 are pressurized, the nitrogen adsorbed inside is externally provided. Each of the pipes for pressure reduction for exhausting is branched, and each part of the pipe is a pilot type solenoid valve (two-port valve) as a switching valve (open / close valve) 51, 52 for pressure reduction. A valve (not shown) having a diaphragm type is attached. In this embodiment, the pressure reducing piping is connected to the secondary side of the pressure reducing switching valves 51 and 52 to form one exhaust pipe, and the exhaust muffler 60 is attached to the outer end (exhaust port). ing. In this embodiment, the switching valves (electromagnetic valves) 41, 42, 51, and 52 are controlled so that the left and right nitrogen adsorption containers 31 and 32 alternately pressurize and depressurize alternately. Has been. Details will be described later.

  On the other hand, on the secondary side (upper side of FIG. 1) of the two nitrogen adsorption vessels 31, 32, pipes for feeding the generated high oxygen concentration gas to the product tank 71 are connected, and each is connected to one main pipe. It is connected to the product tank 71. In this embodiment, check valves 61 and 62 are provided on the secondary side of each nitrogen adsorption container, respectively, on the primary side of the check valve, and two of the two nitrogen adsorption containers 31 and 32 are provided. The secondary side is connected by piping via a two-way valve (direct acting solenoid valve) 64. The operation of the two-way valve 64 will be described later. The secondary pipe of the tank 71 has a regulator (flow rate adjusting valve) 73, a bacteria filter 75, a flow rate setting unit 77, an oxygen sensor 79, a pressure sensor 91, and a humidifier 92 while reaching the oxygen outlet 100. Etc. are attached.

  In the apparatus 101 of this embodiment, the air taken in from the air intake port 2 is compressed by the compressor 21, and the switching valves 41, 42, 51, 52 for pressurization or depressurization are switched and controlled. In the adsorption containers 31 and 32, high oxygen concentration gas is continuously generated and supplied by alternately repeating generation of high concentration oxygen gas by adsorption of nitrogen and pressurization and decompression for regeneration of the adsorbent in a constant cycle. It is configured as follows. The high oxygen concentration gas sent to the tank 71 is subjected to appropriate processing such as flow rate adjustment, and then supplied to the patient from the oxygen outlet 100 via a conduit such as a cannula.

  In the apparatus 101 of this embodiment, while compressed air is supplied to one nitrogen adsorption vessel 31 and pressurized to generate a high oxygen concentration gas, the other nitrogen adsorption vessel 32 exhausts the adsorbed nitrogen ( The adsorbent is regenerated and the adsorbent is regenerated, and each switching valve is controlled to be opened and closed by a control device (not shown) so as to repeat this alternately and periodically. Specifically, it is as follows. For example, when pressurized air is supplied to the nitrogen adsorption container 31 on the left side of the figure to pressurize, the pressure switching valve (hereinafter also referred to as a pressure valve) 41 on the left side of the figure is replaced with a pressure reduction switching valve (hereinafter referred to as a pressure switching valve). (Also referred to as a pressure reducing valve) 51 is opened, and the pressure valve 42 on the right side in the figure is closed while the pressure valve 41 on the left side in the figure is opened. Then, in the state in which the pressurizing valve 42 on the right side in the figure is closed, the pressure reducing valve 52 on the right side in the figure is opened to decompress the inside of the nitrogen adsorption container 32 on the right side in the figure. On the contrary, when pressurized air is supplied to the right side nitrogen adsorption container 32 and pressurized, the pressure valve 42 on the right side of the figure is opened with the pressure reducing valve 52 on the right side closed. The pressure valve 41 on the left side of the figure is closed while the pressure valve 42 on the right side of the figure is opened. Then, in the state in which the pressure valve 41 on the left side in the figure is closed, the pressure reduction valve 51 on the left side in the figure is opened to decompress the inside of the nitrogen adsorption container 31 on the left side in the figure.

  As described above, in this embodiment, on the primary side of the check valves 61 and 62, the secondary side of the two nitrogen adsorption containers 31 and 32 is connected via the two-way valve (direct acting solenoid valve) 64. Piping is connected. This is because when one of the left and right nitrogen adsorption containers shown in the figure is depressurized, a part of the product gas generated in the other nitrogen adsorption container is used as a purge gas to regenerate the adsorbent. It is provided to promote the opening and closing control according to the exhaust. A fixed throttle is provided on each port side of the two-way valve 64.

  As described above, the oxygen concentrator 101 of this embodiment has the same piping configuration as that of the conventional one, but what is important is for pressurization and decompression of the nitrogen adsorption vessels 31 and 32 (all in this embodiment). The switching valves 41, 42, 51, 52 are pilot type solenoid valves, and the main valve is a diaphragm type. That is, since pilot type solenoid valves are used for them, a solenoid valve having a large diameter can be used as compared with the case of using a direct acting type solenoid valve with the same power consumption. The volume can be reduced. That is, according to the pilot type solenoid valve, it is a small valve as a pilot valve that is driven as a solenoid valve, and it opens and closes by operating a large main valve with pilot pressure (air pressure). For this reason, even when a flow passage having a large cross-sectional area is used, the power consumption required for switching the valve can be kept small. In other words, since a pilot type solenoid valve is used, it is possible to use a valve having a large cross-sectional area of the flow path, so that the gas flow loss can be reduced in both the pressurization and decompression steps. Therefore, since the discharge flow rate of the compressor 21 to be used can be reduced, the power consumption required for driving the compressor 21 can be reduced, and thus power saving as the apparatus can be achieved.

  Moreover, the switching valves 41, 42, 51, and 52 used for such pressurization and decompression are not only pilot type solenoid valves, but also because the main valve is a diaphragm type. The main valve has no sliding part for the valve seat. Therefore, as compared with the spool type or poppet type, the structure is not complicated and the reliability can be improved. In addition, since the main valve is a diaphragm type, it is possible to easily increase the cross-sectional area of the flow path, so that the flow loss can be kept small, which can contribute to further power saving. . As described above, the apparatus 101 according to the present embodiment can be an oxygen concentrator that can save power without lowering reliability or durability, which is a gospel for a patient who is at home.

Incidentally, the power consumption required for driving a direct acting solenoid valve having an effective flow path cross-sectional area of 6 mm ² used in a conventional apparatus is 10 W, whereas the effective flow cross-section area is 10 W. Is an 18 mm ² pilot type solenoid valve, and the main valve is a diaphragm type, the power consumption required for driving it is 1 W, and the power consumption required for driving the solenoid valve is 1/10. Also, the same compressor (with a DC brushless motor installed, and the number of revolutions can be varied by inverter control when using such a direct-acting solenoid valve and when using the pilot-type solenoid valve. The generated oxygen concentration is 93 vol. The power consumption of the entire oxygen concentrator was compared. The result was 140 W when the direct acting solenoid valve was used, and 100 W when the pilot solenoid valve was used, which was reduced by about 30%. This proves the effect of the present invention. This is because when the pilot-type solenoid valve described above is used, the effective flow cross-sectional area of the main valve can be secured three times that when a direct-acting solenoid valve is used. As a result, the load on the compressor can be reduced, and as a result, the power consumption of the oxygen concentrator can be greatly reduced.

  In the above embodiment, the four switching valves 41, 42, 51, and 52 have been described as being independent of each other and provided in the middle of each pipe. However, as shown in FIG. It is good to make a manifold. That is, it is assumed that the valve body 201 is formed of, for example, one metal block, and the valves 41, 42, 51, 52 and the flow path (shown by a thick solid line) P forming the above-described piping parts are formed therein. Good. In the same figure, a connection port 203 for supplying compressed air is provided in the lower left portion of the valve body 201 in the figure, and connection ports 205 and 206 for supply to the adsorption containers 31 and 32 are provided on both sides of the upper end in the figure. An exhaust connection port 207 for pressure reduction is provided between them. In FIG. 3, the exhaust connection port 207 is provided on the drawing so that the flow paths do not cross each other, but the circuit is the same as that shown in FIGS. In this case, it is not necessary to provide individual and independent solenoid valves in the middle of each pipe, so that the piping space in the oxygen concentrator can be omitted and the efficiency of the piping work can be improved. In addition, as a form of manifolding, it is good also as what joined the two-way (2 port) change-over valve made into the double connection type.

  The present invention is not limited to the above-described embodiment, and can be embodied by appropriately modifying the design. For example, in the above description, the present invention is embodied as having two nitrogen adsorption containers, but the number can be three or more. The pilot type solenoid valve may be an internal pilot type or an external pilot type. Further, instead of the compressor, an air pump may be used as a compressed air supply source (compressed air supply means).

  Further, a check valve may be provided in a pipe between the switching valve and the nitrogen adsorption container in order to prevent the gas from flowing backward from each switching valve for pressurization. Also. Such a check valve may be provided on the primary side of the switching valve.

The circuit diagram of the oxygen concentration apparatus of this invention. The figure which shows the principal part of FIG. The schematic diagram for description of the 1 aspect which manifolded the some pilot type solenoid valve.

Explanation of symbols

21 Compressor (Compressed air supply source 31, 41 Nitrogen adsorption vessel 41, 42 Pressurizing switching valve 51, 52 Depressurizing switching valve 101 Oxygen concentrator

Claims (3)

Adsorption by reducing the pressure in the nitrogen adsorption vessel and the pressurization process to obtain high oxygen concentration gas by supplying compressed air into the nitrogen adsorption vessel filled with the adsorbent that can adsorb nitrogen preferentially over oxygen A pressure fluctuation adsorption type oxygen concentrator of a method of obtaining a high oxygen concentration gas by alternately and repeatedly performing a decompression step of regenerating the adsorbent by exhausting the generated nitrogen to the outside,
There are two or more nitrogen adsorption containers, and each nitrogen adsorption container is connected to a pipe for supplying compressed air from a compressed air supply source and a pipe for exhausting the adsorbed nitrogen to the outside. In each of these pipes, provided with a switching valve for switching between the pressurization step and the pressure reduction step,
An oxygen concentrator using at least one of the switching valves as a pilot type solenoid valve and a main valve as a diaphragm type valve.   In Claim 1, instead of using at least one of the switching valves as a pilot solenoid valve and using a diaphragm valve as the main valve, all of the switching valves are pilot solenoid valves as a main solenoid valve. An oxygen concentrator using a diaphragm type valve.   The oxygen concentrator according to claim 1 or 2, wherein each pilot type solenoid valve is manifolded.

Images