JP5275671B2 - Oxygen concentrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oxygen concentrator for lowering noises. <P>SOLUTION: The oxygen concentrator of a pressure swing absorption type has: an absorption cylinder for filling up an absorption material for absorbing nitrogen in favor of oxygen; an air compressing means for supplying the absorption cylinder with compressed air; and a flow path switch valve for repeating an absorption process for pressuring the absorption cylinder, absorbing nitrogen in the compressed air, and generating oxygen unabsorbed and a process of attachment/removal for reducing pressure in the absorption cylinder to regenerate the absorption material with regular timing. When two or more flow path switch valves simultaneously operate, timing at which the respective flow path switch valves switch has a minute time deviation. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a pressure fluctuation adsorption type oxygen concentrator using an adsorbent that preferentially adsorbs nitrogen over oxygen, and is particularly used for oxygen inhalation therapy performed on patients with chronic respiratory diseases. The present invention relates to a medical oxygen concentrator. More specifically, the pressure fluctuation that can improve noise by improving the pilot pressure exhaust flow path of the pilot-type flow path switching valve that switches the gas flow path to generate pressure fluctuation in the adsorption cylinder filled with the adsorbent The present invention relates to an adsorption-type oxygen concentrator.

  In recent years, the number of patients suffering from respiratory organ diseases such as asthma, emphysema, and chronic bronchitis has been increasing. One of the most effective treatment methods is oxygen inhalation therapy. Such oxygen inhalation therapy is to allow a patient to inhale oxygen gas or oxygen-enriched air. Oxygen concentrators, liquid oxygen, oxygen gas cylinders, and the like are known as supply sources, but oxygen concentrators are mainly used for home oxygen therapy because of convenience during use and ease of maintenance.

  The oxygen concentrator is a device that concentrates and supplies about 21% of oxygen in the air, and includes a membrane oxygen concentrator using a membrane that selectively permeates oxygen and nitrogen or oxygen preferentially. There is a pressure fluctuation adsorption type oxygen concentrator using an adsorbent that can be adsorbed, but the pressure fluctuation adsorption type oxygen concentrator is the mainstream in terms of the obtained oxygen concentration.

  The pressure fluctuation adsorption type oxygen concentrator is an air compressed by a compressor in an adsorption cylinder filled with molecular sieve zeolite such as 5A type, 13X type, and Li-X type as an adsorbent that selectively adsorbs nitrogen rather than oxygen. By adsorbing nitrogen under pressurized conditions to obtain unadsorbed oxygen-enriched gas, and reducing the pressure in the adsorption cylinder to atmospheric pressure or lower and adsorbing to the adsorbent By alternately repeating the pressure reduction / desorption (regeneration) step of regenerating the adsorbent by purging the generated nitrogen, high-concentration oxygen gas can be continuously generated.

  The oxygen concentrator as in the present invention usually has two or more adsorption cylinders. When one adsorption cylinder is an adsorption process, the other adsorption cylinder is set as a desorption process, and both processes are sequentially switched. Thus, the oxygen-enriched gas can be continuously generated. In order to switch these adsorption cylinders at a constant cycle, a two-way valve or a three-way valve switching valve is used. Since current oxygen concentrators require low power consumption, pilot-type solenoid valves are sometimes used as flow path switching valves. The pilot type solenoid valve can make the solenoid valve part smaller than the direct acting type, but the structure of the valve part is the same except that the drive method is different. Noise is generated during operation.

  In order to provide an oxygen concentrator in which these noises are attenuated and silenced, there has been proposed a method in which a noise source is placed in a storage case composed of a shielding plate and a sound absorbing material (Patent Documents 1 and 2). ). However, this method has a problem that the dead space in the storage case becomes large and the main body of the oxygen concentrator becomes large.

  As another method, a method of soundproofing before noise spreads by attaching a cover made of soundproofing material to the noise generating part itself has been proposed. There is no fundamental solution to the problem. (Patent Document 3)

JP 2004-188123 A JP 2008-11933 A JP 2007-222378 A

  It is an object of the present invention to provide an oxygen concentrating device that reduces the operation noise of the flow path switching valve and realizes low noise by reviewing the operation timing of the flow path switching valve used in such an apparatus. .

  As a result of diligent investigations, the present inventor has found that when switching between the adsorption process and the desorption process, the switching timing when two or more of the flow path switching valves operate simultaneously has a slight time lag. It was found that noise reduction can be realized by operating the

  That is, the present invention has a raw material supply end connected to an air compression means or an exhaust pipe at one end, and a product end for taking out product oxygen at the other end, and is filled with an adsorbent that preferentially adsorbs nitrogen over oxygen. An adsorbing cylinder, an air compression means for supplying compressed air to the adsorbing cylinder, an exhaust pipe for exhausting nitrogen adsorbed on the adsorbent to the atmosphere, and pressurizing the adsorbing cylinder to adsorb nitrogen in the compressed air and unadsorb The air compression means, the adsorption cylinder, and the exhaust pipe are repeated at a fixed timing to repeat the adsorption process for generating oxygen and the desorption process for reducing the adsorption cylinder and desorbing and exhausting the adsorbed nitrogen to regenerate the adsorbent. And a plurality of flow path switching valves for switching the flow path between the two and the flow path switching valves at the time of the process switching, The switching timing of the path switching valve There is provided an oxygen concentrator characterized in that it comprises a by causing passage switching control means operating with a record.

  In the present invention, the flow path switching control means is a means for operating each flow path switching valve with a minute time lag of 0.2 seconds to 0.4 seconds as to the switching timing of each flow path switching valve, or It is an object of the present invention to provide an oxygen concentrator that is a means for operating each flow path switching valve with a time lag that falls within a range of 2 to 10 dBA than the maximum sound pressure when the flow path switching valve is operated alone.

  Further, according to the present invention, the adsorption cylinder is composed of two adsorption cylinders A and B, the flow path switching valve is a two-way electromagnetic valve, and the switching provided in the flow path between the air compression means and the adsorption cylinder A Valve A, switching valve B provided in the flow path between the adsorption cylinder A and the exhaust pipe, switching valve C provided in the flow path between the air compression means and the adsorption cylinder B, between the adsorption cylinder B and the exhaust pipe A switching valve D provided in the flow path, and the flow path switching control means is a means for controlling the switching timing of the switching valves A, B, C, D, the adsorption cylinder A, and the adsorption cylinder A A pressure equalizing flow path including a pressure equalizing valve for connecting the product end sides of the cylinder B, and the flow path switching means controls the switching timing of the pressure equalizing valve and the switching valves A, B, C, D An oxygen concentrator is provided.

  The present invention also provides the above-described oxygen concentrator, wherein the flow path switching valve is a pilot solenoid valve or a direct acting solenoid valve.

  By using the oxygen concentrator of the present invention, noise generated when the flow path switching valve is operated can be reduced, and the oxygen concentrator can be silenced.

Embodiment examples of the oxygen concentrator of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic apparatus configuration diagram illustrating a pressure fluctuation adsorption type oxygen concentrator as an embodiment of the present invention. In FIG. 1, 1 is an oxygen concentrator, and 3 is a user (patient) who inhales humidified oxygen-enriched air. The pressure fluctuation adsorption type oxygen concentrator 1 includes an external air intake filter 101, an intake silencer 102, a compressor 103, a flow path switching valve 104, an adsorption cylinder 105, a check valve 106, a product tank 107, a pressure regulating valve 108, a flow rate setting means. 109 and a particle filter 110 are provided. Thereby, oxygen-enriched air obtained by concentrating oxygen gas from the raw material air taken in from the outside can be produced. Further, the humidifier 201 for humidifying the generated oxygen-enriched air, the set value of the flow rate setting means 109, and the measured values of the oxygen concentration sensor 301 and the flow rate sensor 302 are used in the casing of the oxygen concentrator. A control means 401 for controlling the compressor and the flow path switching valve, a compressor box 501 for preventing noise from the compressor, and a cooling fan 502 for cooling the compressor are incorporated.

  First, raw material air taken in from the outside is taken in from an air intake port provided with an external air intake filter 101 and an intake silencer 102 for removing foreign matters such as dust. At this time, the normal air contains 1.2% of oxygen gas of about 21%, nitrogen gas of about 77%, argon gas of 0.8%, water vapor and the like. In such an apparatus, only oxygen gas necessary as a breathing gas is concentrated and extracted.

  The oxygen gas is taken out from the adsorption cylinder filled with an adsorbent made of zeolite or the like that selectively adsorbs nitrogen gas molecules rather than oxygen gas molecules. While the cylinders are sequentially switched, the source air is pressurized and supplied by the compressor 103, and approximately 77% of nitrogen gas contained in the source air is selectively adsorbed and removed in the adsorption cylinder.

The adsorption cylinder is formed of a cylindrical container filled with the adsorbent, and usually a multi-cylinder type of three or more cylinders is used in addition to the one-cylinder type and the two-cylinder type. In order to produce oxygen-enriched air from raw material air, it is preferable to use a multi-cylinder type adsorption cylinder. As the compressor, a swing type air compressor may be used, and a rotary type air compressor such as a screw type, a rotary type, or a scroll type may be used. Further, the power source of the electric motor that drives the compressor may be alternating current or direct current.
Oxygen-enriched air mainly composed of oxygen gas that has not been adsorbed by the adsorption cylinder 105 flows into the product tank 107 through a check valve 106 provided so as not to flow backward to the adsorption cylinder.

  Further, the nitrogen gas adsorbed by the adsorbent filled in the adsorption cylinder needs to be desorbed from the adsorbent in order to adsorb the nitrogen gas again from the newly introduced raw material air. For this purpose, the pressurized state realized by the compressor is switched to the reduced pressure state (for example, the atmospheric pressure state or the negative pressure state) by the flow path switching valve, and the adsorbent is regenerated by desorbing the adsorbed nitrogen gas. In this desorption process, in order to increase the desorption efficiency, oxygen-enriched air may be allowed to flow back as a purge gas from the product end side or product tank of the adsorption cylinder during the adsorption process. In general, a loud air flow noise is generated when nitrogen is desorbed, so a nitrogen exhaust silencer 503 is generally used.

  Oxygen-enriched air generated from the raw air is stored in the product tank. The oxygen-enriched air stored in this product tank contains high concentration oxygen gas, for example, 95%, and the humidifier is controlled while the supply flow rate and pressure are controlled by the pressure regulating valve 108 and the flow rate setting means 109. Supplied to 201 and humidified oxygen-enriched air is supplied to the patient. In such a humidifier, a moisture permeable membrane module having a moisture permeable membrane takes in moisture from external air and supplies it to dry oxygen-enriched air, a bubbling humidifier using water, Alternatively, a surface evaporation humidifier can be used.

  Further, the set value of the flow rate setting means 109 is detected, and the control means 401 controls the number of rotations of the compressor motor, thereby controlling the amount of air supplied to the adsorption cylinder. When the set flow rate is low, the amount of generated oxygen can be suppressed and the power consumption can be reduced by reducing the rotation speed.

  Since the compressor usually generates annoying noise, the compressor is installed in the compressor box 501 to prevent the noise. In addition, since most of the calorific value of the oxygen concentrator is generated from the compressor, a cooling fan 502 is installed in the compressor box to cool the compressor. As the cooling fan, an axial flow type cooling fan, a centrifugal blower, or the like is used. The driving method may be alternating current or direct current. In order to prevent overcooling and reduce noise, the rotation speed of the cooling fan is also controlled. The direction of the cooling air may be either a forced convection method that ventilates the air in the compressor box or a forced air cooling method that directly applies the cooling air to the compressor.

  FIG. 2 shows the flow path switching valve 104 used in the oxygen concentrator of the present invention in more detail. Although this figure shows a method using four two-way valves, a method using two three-way valves may be used.

  FIG. 3 shows an example of the operation timing of the flow path switching valve when four flow path switching valves are used as shown in FIG. When four flow path switching valves are used as shown in this figure, when switching the adsorption cylinder A105A to the pressure adsorption process and the adsorption cylinder B105B to the vacuum exhaust process, the switching valve 104A and the switching valve 104D are opened, This is possible by closing 104B and 104C. Further, when the adsorption cylinder A104A is in the decompression exhaust process and the adsorption cylinder B104B is in the pressure adsorption process, it is possible to close the switching valves 104A and 104D and open the switching valves 104B and 104C. According to this figure, it can be seen that at timing A and timing B, three flow path switching valves are simultaneously operated.

  When two channel switching valves that generate noise of the same sound pressure level are operated at the same time, the noise increases by 3 dB from when one is operated alone, and when three are operated simultaneously. Although the noise increases by 5 dB, in the oxygen concentrator according to the present invention, these flow path switching valves operate with a slight time lag, so that each flow path switching valve operates individually and generates noise at the same time. Therefore, almost the same noise level as when operated alone can be realized.

  Hereinafter, preferred specific examples of the oxygen concentrator of the present invention will be described. The flow path switching valve used in this example uses four pilot type solenoid valves manufactured by SMC, which are operated at the operation timing shown in FIG. 3 with a time difference of ± 0.3 seconds. The generated noise was measured. As a comparative example, noise generated when three flow path switching valves having the same configuration as in the example were simultaneously operated at the operation timing shown in FIG. 3 was measured. The measurement was performed in an anechoic chamber with a background noise level of 17 dBA, and the distance between the sound collection microphone and the flow path switching valve was separated by 1.0 m, and the A characteristic sound pressure level was measured.

FIG. 4 shows the noise level when one of the flow path switching valves used in this example is operated alone. From this figure, it can be seen that the operating noise of one flow path switching valve is about 35 dBA.
FIG. 5 is a noise level showing the present embodiment, and shows that the three flow path switching valves are operating with a time difference of 0.3 seconds. From this figure, it can be seen that the maximum noise level is 35 dBA, which is almost the same as when operating alone. FIG. 6 is a noise level showing a comparative example, and it can be seen that noise of about 40 dBA is generated when three flow path switching valves are operated simultaneously.

  When three flow path switching valves are operated at a time difference of 0.1 seconds, the noise level (35 dBA) of each single operation rises by about 2 dBA to 37 dBA, but it operates at the same time (zero time difference). Compared to 40 dBA in the case of making it, the noise reduction effect is recognized. Further, when the three flow path switching valves are operated with a time difference of 0.2 seconds, the noise level is increased by 1 dBA to 36 dBA with respect to the noise level of the single operation. Note that even if the operation is performed with a time difference longer than 0.4 seconds, the noise level does not become lower than the single operation noise level, which adversely affects the adsorption sequence. Similarly, when the sound pressure level difference between two sound sources is 2 to 4 dB (0.1 second difference, 33 dBA), +2 dB (37 dBA), and when the sound pressure level difference is 5 to 9 dB (0.2 second difference, 28 dBA), +1 dB (36 dBA) When the sound pressure level difference is 10 dB or more, the smaller sound is masked and only the larger sound is heard. Therefore, if the sound pressure level difference between the two sound sources is in the range of 2 to 10 dBA, especially when the time difference is about 10 dBA and the time difference is 0.3 seconds, the effect on the adsorption sequence is minimized. It is preferable also from a surface.

  From these results, it is possible to reduce the noise level by using the technique of the present invention without attaching a special soundproof cover.

The schematic diagram of the pressure fluctuation adsorption type oxygen concentrator which is an embodiment of the oxygen concentrator of the present invention. The schematic diagram which showed the structure of the flow-path switching valve which is the example of an embodiment of the oxygen concentration apparatus of this invention. The schematic diagram which showed the action | operation timing of the flow-path switching valve which is the example of an embodiment of the oxygen concentration apparatus of this invention. Noise level when one of the flow path switching valves used in the embodiment of the present invention is operated alone. The noise level which shows the Example of this invention. Noise level shown in the comparative example.

Explanation of symbols

1: Oxygen concentrator 2: Waterless humidifier 3: User
101: External air intake filter
102: Intake silencer
103: Compressor
104: Flow path switching valve
105: Adsorption cylinder
106: Pressure equalizing valve
107: Check valve
108: Product tank
109: Pressure regulating valve
110: Flow rate setting method
111: Particle filter
201: Humidifier
301: Oxygen concentration sensor
302: Flow sensor
401: Control means
501: Compressor box
502: Cooling fan
503: Silencer

Claims (5)

A raw material supply end connected to an air compression means or an exhaust pipe at one end, a product end for taking out product oxygen at the other end, and an adsorption cylinder filled with an adsorbent that preferentially adsorbs nitrogen over oxygen; Air compression means for supplying compressed air to the adsorption cylinder, an exhaust pipe for exhausting the nitrogen adsorbed on the adsorbent to the atmosphere, and adsorption that pressurizes the adsorption cylinder and adsorbs nitrogen in the compressed air to generate unadsorbed oxygen A flow path between the air compression means, the adsorption cylinder and the exhaust pipe for repeating the process and the desorption process of depressurizing the adsorption cylinder and desorbing and exhausting the adsorbed nitrogen to regenerate the adsorbent at a fixed timing. A pressure fluctuation adsorption type oxygen concentrating device comprising a plurality of flow path switching valves for switching between,
When controlled to operate the plurality of flow path switching valve during the process is switched at the same time, the switching timing of each of the respective flow passage switching valve, the flow paths with a deviation of 0.4 seconds or less short time An oxygen concentrator having flow path switching control means for operating a switching valve . Passage switching control means, the cut conversion example timing of each of the flow path switching valve, the channel switching with time lag to be reduced in a range of 2~10dBA than the maximum sound pressure when the flow path switching valve alone operation The oxygen concentrator according to claim 1, which is a means for operating a valve. The adsorption cylinder is composed of two adsorption cylinders A and B, the flow path switching valve is a two-way solenoid valve, and the switching valve A and the adsorption cylinder provided in the flow path between the air compression means and the adsorption cylinder A Switching valve B provided in the flow path between A and the exhaust pipe, switching valve C provided in the flow path between the air compression means and the adsorption cylinder B, provided in the flow path between the adsorption cylinder B and the exhaust pipe was selector valve provided with a D, the channel switching control means switching valve a, B, C, oxygen concentrator according to claim 1 or 2 which is a means for controlling the cut-conversion example timing of D. A pressure equalizing flow path provided with a pressure equalizing valve for connecting the product end sides of the adsorption cylinder A and the adsorption cylinder B, and the flow path switching means switches the pressure equalizing valve and the switching valves A, B, C, D. oxygen concentrator according to claim 3, wherein the means for controlling the conversion example timing. The oxygen concentrator according to any one of claims 1 to 4 , wherein the flow path switching valve is a pilot solenoid valve or a direct acting solenoid valve.

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