JP2008272350A - Oxygen concentrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oxygen concentrator realizing the reduction of noise and power consumption by dispensing with an excessive cooling of the concentrator. <P>SOLUTION: This oxygen concentrator is provided with at least one adsorption bed 3 filled with adsorbent for adsorbing nitrogen preferentially to oxygen, an air compression means 2 supplying compressed air to the adsorption bed, making it adsorb the nitrogen and generating oxygen-concentrated gas, a temperature detection means 8 for detecting the temperature of the air compression means, and an air blower means 7 for cooling the air compression means; and is further provided with a control means 9 for controlling the actuation of the air blower means based on the temperature acquired by the temperature detection means, when the temperature detection means detects an upper limit temperature value or higher, controlling the air blower means to increase the air blowing volume and, when it detects a lower limit temperature or lower, controlling the air blower means to decrease the air blowing volume. <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.

  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 for concentrating and supplying about 21% oxygen present in the air to the user, and includes a membrane oxygen concentrator using a membrane that selectively permeates oxygen, nitrogen or There is a pressure fluctuation adsorption type oxygen concentrator using an adsorbent capable of preferentially adsorbing oxygen, but the pressure fluctuation adsorption type oxygen concentrator is the mainstream in terms of the obtained oxygen concentration.

  As such a pressure fluctuation adsorption type oxygen concentrator, an oxygen concentrator in which one or a plurality of adsorbents such as zeolite capable of selectively adsorbing nitrogen or oxygen is filled is known. Usually, an adsorption process, adsorption, in which oxygen-concentrated gas is obtained by supplying compressed air to one or more adsorption cylinders filled with an adsorbent capable of selectively adsorbing nitrogen and adsorbing nitrogen in a pressurized state. A desorption process in which nitrogen is desorbed by reducing the internal pressure of the cylinder to regenerate the adsorbent, and a portion of the dry oxygen-concentrated gas that has already been generated just before the desorption process is backflowed to improve the regeneration efficiency and increase the pressure. This is an apparatus for obtaining an oxygen-enriched gas by sequentially performing the pressure step in a constant cycle.

JP 2004-018313 A Japanese Patent Laid-Open No. 2003-246607 Japanese Patent Laid-Open No. 2001-278606

In order to use such oxygen concentrators for home use and medical applications, it is essential to reduce the size of the device, extend its life, and stabilize the device. Cooling the compressor, which accounts for the majority of heat generation in the device, is an essential requirement. Become.
As a method for cooling the compressor in the apparatus for obtaining the oxygen-enriched gas, as shown in Japanese Patent Laid-Open No. 2001-278606, cooling air is forced from above the compressor box by a cooling fan (blower means) such as a fan or a blower. It is common to convect and exhaust from the lower exhaust port.

  Furthermore, as a method for uniformly and efficiently cooling an oscillating and reciprocating compressor housed in a compressor box used in an oxygen concentrator, JP 2003-246607 A includes a cooling fan at the top of the compressor box. The oxygen flow is characterized in that the air flow by the cooling fan is sucked from the intake opening disposed at the lower part of the box, diffracted at the lower surface of the compressor, and then discharged from the exhaust opening disposed at the upper part of the box. A concentrator is described.

  Japanese Patent Laid-Open No. 2004-18313 discloses an installation environment temperature and / or a compressed air temperature as an oxygen concentrator for home medical care that can easily secure a predetermined oxygen concentration in a low temperature environment such as winter. Temperature detecting means for detecting is provided, and the driving of the cooling air blowing means is controlled based on either the detected installation environment temperature or the compressed air temperature so that the compressed air becomes a predetermined target temperature corresponding to the oxygen concentration condition. An apparatus with drive control means is described.

Cooling of the oxygen concentrator housing, especially the compressor that accounts for the majority of the heat source, is an essential element for maintaining the long-term durability of the equipment. In the meantime, it is equipped with a cooling fan that has the required equipment cooling capacity under guaranteed operating conditions. Large cooling fans consume more power and generate more noise.
It is an object of the present invention to provide an apparatus that reduces noise and power consumption by measuring the temperature of the compressor of such an apparatus and controlling the blowing means according to the situation to eliminate excessive cooling.

  The present invention provides an oxygen concentrator as described below as means for solving such problems. That is, the present invention generates at least one adsorbent bed filled with an adsorbent that preferentially adsorbs nitrogen over oxygen, and generates oxygen-enriched gas by supplying compressed air to the adsorbent bed to adsorb nitrogen. In the oxygen concentrating apparatus provided with the air compression means for detecting the temperature, the temperature detection means for detecting the temperature of the air compression means, and the air blowing means for cooling the air compression means, the air blowing means based on the temperature obtained by the temperature detection means Control means for controlling the driving of the air supply, and when the temperature detection means detects a value equal to or higher than a preset upper limit temperature value, the control for increasing the air flow rate of the blower means detects a value lower than the lower limit temperature value. In such a case, an oxygen concentrating device is provided which is a means for performing control to reduce the amount of air blown by the air blowing means.

  The present invention also provides an oxygen concentrator characterized in that the air blowing means is a cooling fan driven by PWM control or a cooling fan driven by switching an applied voltage.

  The oxygen concentrator of the present invention can be applied to a medical oxygen concentrator used for oxygen inhalation therapy performed for patients with chronic respiratory diseases and the like, and is a cooling means according to the use environment of the device. By controlling the operation of the blowing means, it is possible to reduce noise and power consumption.

  An oxygen concentration apparatus of pressure fluctuation adsorption type as an embodiment of the present invention detects an air compression means for compressing and supplying raw material air, a blowing means for cooling the air compression means, and a temperature of the air compression means. A temperature detection unit is provided, and a drive control unit that monitors the state of the air compression unit based on the temperature detection unit and controls the driving of the blower unit is provided. Specifically, the driving state of the air blowing means is controlled when the air compression means reaches a predetermined switching temperature.

  The pressure fluctuation adsorption type oxygen concentrator having such a configuration compresses intake air by an air compression means, and sends the compressed air to an adsorption bed to adsorb nitrogen and send out concentrated oxygen. Since the air blowing means determines whether or not the air compressing means is excessively cooled based on the temperature of the air compressing means detected at this time and controls it, noise and power consumption can be reduced.

An embodiment of the oxygen concentrator of the present invention will be described with reference to the drawings.
A system configuration diagram of the pressure fluctuation adsorption type oxygen concentrator is shown in FIG. Oxygen concentrator 1 is a product tank for temporarily storing concentrated oxygen generated through a compressor 2 that sucks and compresses air, and adsorption cylinders 3 and 3 filled with an adsorbent that selectively adsorbs nitrogen from the compressed air. 4. Consists of a pressure regulator 5 that adjusts the pressure of product oxygen, and the cannula 6 supplies concentrated oxygen to the user.

  This oxygen gas is extracted by filling the material air with adsorbents such as zeolites such as 5A, 13X, Li-X, and MD-X that selectively adsorb nitrogen gas molecules over oxygen gas molecules. While the target adsorption cylinder is sequentially switched by the switching valve to the adsorption cylinder, the raw material air is pressurized and supplied by the compressor, and approximately 77% nitrogen gas contained in the raw air is selectively contained in the adsorption cylinder. Remove by adsorption.

  The adsorbing cylinder 3 is formed of a cylindrical container filled with the adsorbent, and usually a multi-cylinder type of 3 or more cylinders is used in addition to the 1-cylinder type and the 2-cylinder type. In order to produce oxygen-enriched air from raw material air, it is preferable to use a two-cylinder or multi-cylinder type adsorption cylinder.

  As the compressor 2, a two-head type oscillating air compressor is used as a compressor having a compression function and a vacuum function, and a rotary air compressor such as a screw type, a rotary type, a scroll type, or the like is used. Sometimes used. The power source of the motor that drives the compressor 2 may be alternating current or direct current.

  Specifically, the compressor 2 includes a cooling fan 7, a temperature sensor 8 that detects the motor temperature, and a cooling fan control circuit 9. The control circuit 9 performs an operation determined according to the detection value of the temperature sensor 8. The air flow rate of the cooling fan 7 is controlled. In addition to the cooling fan 7 that cools only the compressor 2, it also has a cooling fan 7 ′ that takes outside air into the device and cools the entire interior including the electrical components. By controlling the number of revolutions, the cooling efficiency of the entire device is optimized. The cooling fan 7 and the cooling fan 7 'can be an axial fan, a sirocco fan, etc., and the motor rotation speed of each cooling fan can be controlled continuously by PWM control or switching of applied voltage such as 24V, 12V, 0V, etc. Rotational speed control by control can be employed.

Further, the intake pipe 10 of the compressor 2 includes an intake filter 11, an intake filter 12, a silencer 13, and the like. An air supply pipe 15 is connected to the discharge side via a heat exchanger 14. A silencer 17 is connected to the exhaust pipe 16.
The two adsorbing cylinders 3 and 3 are respectively provided with switching valves 18 and 18 for controlling the flow of compressed air, the pressure-feeding valve 20 on the delivery side, and the check valves 21 and 21 respectively. Is connected to the product tank 4 for temporary storage.
Further up to the cannula 6, a pressure regulator 5, an oxygen concentration sensor 19, a flow rate regulator 22, and a particle filter 13 are provided.

  In the pressure fluctuation type oxygen concentrator having the above-described configuration, the concentrated oxygen is delivered by compressing the raw material air and sending it to the nitrogen adsorption section. Since the cooling fan controller monitors the motor temperature of the compressor, it grasps the temperature state of the compressor and operates the cooling fan. For example, the temperature of the compressor is measured at intervals of 0.5 seconds, and the driving state of the cooling fan is controlled by determining whether the temperature is low, usually high. Without temperature control, the cooling fan is always driven, which causes overcooling of the compressor and unnecessary power consumption. However, monitoring the temperature of the compressor eliminates overcooling of the compressor and reduces noise and consumption. Realize power reduction.

  In recent years, any electronic device is required to have low power consumption. In particular, in home medical equipment such as this device, a reduction in power consumption leads to a reduction in the burden on the user, which is important from the viewpoint of improving QOL. Compared to conventional continuous cooling fan operation, overcooling prevention of the cooling fan by monitoring the temperature of the compressor can stop the cooling fan when cooling is unnecessary, and power consumption is reliably reduced.

  This device is often used at home and in hospitals, and noise reduction is an important item for users as well as low power consumption. In conventional fan continuous operation, wind noise from the fan is large, and noise reduction has been desired. According to this apparatus, since the cooling fan is stopped when cooling is unnecessary, there is no wind noise generated by the cooling fan, and low noise can be realized.

  Effect on power consumption and noise reduction by controlling the rotation of the cooling fan based on the detection result of the compressor temperature using the pressure fluctuation adsorption type oxygen concentrator having the maximum oxygen production capacity of 2 L / min shown in FIG. Confirmed the effect. Such a device includes a sirocco fan 7 'for cooling the entire device and two axial fans 7 and 7 for directly cooling the cylinder portion of the two-head type reciprocating compressor 2 as cooling fans.

  The operating temperature of the cooling fan was changed by changing the temperature of the compressor by changing the external environmental temperature to −5 ° C., 25 ° C., and 35 ° C. while operating the compressor at a constant rotational speed.

  The number of rotations of the cooling fan is controlled for the sirocco fan 7 'when the compressor temperature is less than 30 ° C, and is continuously operated when the compressor temperature is less than 30 ° C. For the axial fan 7, the compressor temperature is less than 30 ° C and 0V, 30 ° C or more Control was performed to drive at a voltage of 12V below 65 ° C and 24V above 65 ° C.

  At an ambient temperature of -5 ° C, the compressor temperature t is 30 ° C or less and the cooling fans 7 and 7 'are both OFF. At an ambient temperature of 25 ° C, the compressor temperature t is 30 ° C or more and less than 65 ° C, and the sirocco fan 7 'Was driven at 12V, and the axial fan 7 was operated continuously. Furthermore, at an environmental temperature of 35 ° C., the compressor temperature was 65 ° C. or higher, and the sirocco fan 7 ′ was driven at 24V.

  The results are shown in Tables 1 and 2. As a comparison, the results of power consumption and noise measurement when the cooling fan control is not performed (OFF) are shown. Reduce power consumption by a maximum of 5.39 [W] (average power consumption at an ambient temperature of -5 ° C) and a minimum of 3.18 [W] (average power consumption at an ambient temperature of 35 ° C), depending on whether the cooling fan is controlled or not. I was able to. Regarding noise, the noise is reduced from 0.2 [dBA] to 3.2 [dBA]. As a result of measuring the noise at the front, rear, left and right of the device, it became clear that the noise on the right rear side, especially when looking at the machine base with the exhaust vent in front, is greatly influenced by the presence or absence of control of the cooling fan.

Explanatory drawing of the example of an embodiment of this invention.

Explanation of symbols

1. 1. oxygen concentrator Compressor (Air compression means)
3. Adsorption cylinder (adsorption bed)
4). Product tank 5. Pressure regulator 6. Cannula 7. Cooling fan 8. Temperature sensor 9. 9. Cooling fan control circuit Intake pipe 11. Intake filter 12. Intake filter 13. Silencer 14. Heat exchanger 15. Air pipe 16. Exhaust pipe 17. Silencer 18. Switching valve 19. Oxygen concentration sensor 20. Equalizing valve 21. Check valve 22. Flow regulator

Claims (3)

  At least one adsorption bed filled with an adsorbent that preferentially adsorbs nitrogen over oxygen, and air compression means for generating oxygen-enriched gas by supplying compressed air to the adsorption bed and adsorbing nitrogen In the oxygen concentrator provided with the temperature detecting means for detecting the temperature of the air compressing means and the blowing means for cooling the air compressing means, the driving of the blowing means is controlled based on the temperature obtained by the temperature detecting means. Control means, and when the temperature detection means detects a value equal to or higher than the upper limit temperature value, the control for increasing the air flow rate of the blower means is performed. An oxygen concentrator, characterized in that it is a means for performing control to reduce the amount of air blown.   2. The oxygen concentrator according to claim 1, wherein the blowing means is a cooling fan driven by PWM control.   2. The oxygen concentrator according to claim 1, wherein the blower is a cooling fan that is driven by switching an applied voltage.