JP2009061110A - Oxygen concentrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve noise of an oxygen concentrator by reducing air flow noise to be caused in discharging pilot pressure (air pressure) when a pilot type solenoid valve is used as a flow path switching valve to be mounted on an adsorption type oxygen concentrator. <P>SOLUTION: The pressure swing adsorption type oxygen concentrator comprises at least one adsorbing cylinder filled with adsorbent preferably adsorbing nitrogen rather than oxygen; the flow path switching valve for repeating in fixed timing a desorbing process for decompressing the adsorbing cylinder and regenerating the adsorbent; an air compressing means having at least one or more compression chambers for supplying pressurized air to the adsorbing cylinder; and a sound insulation box for preventing the noise of the air compressing means. In the oxygen concentrator, the flow path switching valve is the pilot type solenoid valve, the pilot pressure discharge port of the flow path switching valve is introduced into the sound insulation box, and the noise to be caused by the pilot pressure to be discharged from the flow path switching valve is prevented by the sound insulation box. <P>COPYRIGHT: (C)2009,JPO&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 in 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 decompression step of regenerating the adsorbent by purging 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 a pressure adsorption process, the other adsorption cylinder is set to a decompression process, and both processes are sequentially switched. By implementing this, oxygen-enriched gas can be continuously generated. However, 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, a pilot-type solenoid valve may be used as the flow path switching valve. The pilot-type solenoid valve is a small valve as a pilot valve that is driven by electric power. Since the large main valve is operated by the pilot pressure (air pressure), the power consumption of the flow path switching valve can be reduced. (Patent Document 1, Patent Document 2, and Patent Document 3).

  However, in an oxygen concentrator using a pilot-type flow path switching valve, there is a process in which a pilot pressure is exhausted when the valve is opened and closed. As a solution to this problem, a pilot-type solenoid valve with a silencer made of sintered metal attached to the pilot pressure exhaust port is commercially available. The effect is not enough. In addition, a method of exhausting the pilot pressure to the piping for purging nitrogen gas and silencing with a nitrogen purge silencer has been proposed, and oxygen concentrators equipped with it are also commercially available. Since the timing and the timing of the nitrogen purge overlap, the back pressure becomes high, and as a result, sufficient pilot pressure exhaust is not performed, causing a malfunction in the opening and closing of the main valve.

  As a method for solving these problems, a method has been proposed in which the flow path switching valve body is surrounded by a sound insulation box to silence the noise generated from the changeover valve. However, it is difficult to reduce the size and weight of the apparatus, and various problems remain such as deterioration in assemblability and maintainability (Patent Document 4).

JP 2006-62932 A JP 2005-329251 A JP-A-62-140619 Japanese Patent Laid-Open No. 7-255851

  The present invention improves the air flow noise associated with exhausting pilot pressure in an oxygen concentrator using a pilot type solenoid valve as a flow switching valve by reviewing the flow switching valve piping of such a device. An object of the present invention is to provide a device that realizes the system.

  As a result of diligent studies on the problem, the present inventors have found the following oxygen concentrator. That is, the present invention provides at least one adsorption cylinder filled with an adsorbent that preferentially adsorbs nitrogen over oxygen, and a flow path for repeating the desorption process of depressurizing the adsorbent and regenerating the adsorbent at a fixed timing. Pressure fluctuation adsorption type oxygen concentrating apparatus comprising a switching valve, an air compression means having one or more compression chambers for supplying compressed air to the adsorption cylinder, and a sound insulation box for preventing noise from the air compression means The flow path switching valve is a pilot-type solenoid valve, and includes a connection line connecting the pilot pressure exhaust port of the flow path switching valve and the sound insulation box, and the pilot pressure discharged from the flow path switching valve It is an object of the present invention to provide an oxygen concentrator that is soundproofed by introducing noise generated in the sound insulation box.

  In the present invention, the flow path switching valve is a pilot-type electromagnetic valve, and is a two-way valve capable of switching the flow path in one direction or a three-way valve capable of switching the flow path in two directions. An oxygen concentrator is provided.

  By using the oxygen concentrator of the present invention, particularly noise of 2 kHz or less can be greatly reduced, and the quietness of the oxygen concentrator can be improved.

Embodiment examples of the oxygen concentrator of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic device configuration diagram illustrating a pressure fluctuation adsorption type oxygen concentrator as an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an oxygen concentrator, and 3 denotes 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 adsorbed material 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. Also, 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. In this figure, 601 is a flow path switching valve manifold, 602 is a pilot solenoid valve, 603 is a pilot pressure exhaust pipe, and 501 is a compressor box. The source air supplied from the compressor side passes through the source air supply pipe 604, the flow path is switched by each pilot solenoid valve 602, and is supplied to the adsorption cylinder 105. Further, in the desorption process, the adsorption cylinder 105 passes through the pilot solenoid valve 602 and is exhausted through the nitrogen exhaust pipe 605.

  When each flow path switching valve is driven, it is driven by the pilot pressure. In the normally closed pilot type solenoid valve used in the present invention, the main valve is closed and the pilot pressure is exhausted when the pilot pressure is applied. The main valve operates to open when not added. When the main valve operates from closing to opening, the pilot pressure is exhausted. At this time, a large air flow noise is generated. In the present invention, pilot pressure exhaust is introduced into a compressor box 501 having soundproof performance and exhausted to realize a silent oxygen concentrator.

  Hereinafter, preferred specific examples of the oxygen concentrator of the present invention will be described. The oxygen concentrator used in this example is composed of two adsorption cylinders filled with Li-X zeolite as an adsorbent capable of selectively adsorbing nitrogen rather than oxygen, and a compressor for supplying compressed air to the adsorption cylinder The oxygen which can be produced | generated and the density | concentration of 90 volume% or more and the apparatus which has the capability of the maximum oxygen flow rate of 3 L / min were used. A rigid nylon tube was used for the pilot pressure exhaust pipe.

  As a comparative example, a comparison was made between the case where pilot pressure exhaust was exhausted directly outside the switching valve manifold and the case where sound was silenced by a silencer made of sintered metal (configuration in FIG. 3). The method of exhausting pilot pressure exhaust gas to the nitrogen exhaust pipe (configuration shown in FIG. 4) is not presented in this embodiment because basic performance such as reduction in product oxygen concentration and increase in power consumption is reduced.

  The operating conditions and the environmental conditions of the oxygen concentrator were all the same, and the A characteristic sound pressure level was measured when the operation was stabilized at a maximum oxygen flow rate of 3 L / min at an environmental temperature of 25 ° C. As a result, as shown in FIG. 5, by using the oxygen concentrator of the present invention, the noise of 2 kHz or less is greatly reduced, and it can be seen that the noise of the oxygen concentrator can be improved.

The schematic diagram of the pressure fluctuation adsorption type oxygen concentrator which is an embodiment of the oxygen concentrator of the present invention. The structural diagram of the flow-path switching valve mounted in the oxygen concentration apparatus of this invention. The block diagram of the flow-path switching valve which uses a general silencer for the silence of pilot pressure exhaust. FIG. 3 is a structural diagram of a flow path switching valve in which pilot pressure exhaust is introduced into a nitrogen gas exhaust pipe to achieve silence. A characteristic sound pressure level when pilot pressure exhaust is exhausted directly outside the switching valve manifold, when the exhaust is silenced through a silencer made of sintered metal, and when the configuration according to the present invention is implemented.

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: Check valve
107: Product tank
108: Pressure regulating valve
109: Flow rate setting method
110: Particle filter
201: Humidifier
301: Oxygen concentration sensor
302: Flow sensor
401: Control means
501: Compressor box
502: Cooling fan
503: Nitrogen exhaust silencer
504: Pilot pressure exhaust piping
601: Flow path switching valve manifold
602: Pilot type solenoid valve (two-way valve)
603: Pilot pressure exhaust pipe
604: Raw material air supply piping
605: Nitrogen gas exhaust pipe
606: Pilot pressure exhaust silencer (sintered metal silencer)

Claims (3)

  An adsorption cylinder filled with an adsorbent that preferentially adsorbs nitrogen over oxygen, an air compression means for supplying compressed air to the adsorption cylinder, and pressurizing the adsorption cylinder to adsorb nitrogen in the compressed air Pressure fluctuation adsorption provided with a flow path switching valve for repeating an adsorption process for generating oxygen and a desorption process for depressurizing the adsorption cylinder and regenerating the adsorbent at a fixed timing, and a sound insulation box surrounding the air compression means In the oxygen concentration apparatus, the flow path switching valve is a pilot-type solenoid valve, and the oxygen concentration apparatus is provided with a connection pipe line that connects the pilot pressure exhaust port of the flow path switching valve and the sound insulation box apparatus.   2. The oxygen concentrator according to claim 1, wherein the flow path switching valve is a pilot-type electromagnetic valve and is a two-way valve capable of switching the flow path in one direction.   2. The oxygen concentrator according to claim 1, wherein the flow path switching valve is a pilot type electromagnetic valve and is a three-way valve capable of switching the flow path in two directions.

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