JP2011092622A - Oxygen enriching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oxygen enriching device capable of restraining a load of a compressor at the time when the device stops, capable of restraining a noise and vibration from being generated, capable of restraining therein an adsorbent from being deteriorated with moisture adsorption after the device stops, and provided thereby with a function for discharging surely, to an outside, adsorbed water staying in a piping system and dew-condensed water in a pipe. <P>SOLUTION: This oxygen enriching device carries out sequentially controls of (1) executing an operation at a regular sequence until finishing a purge generation process or until finishing a purge exhaustion process, when recognizing an operation stop signal of the device, (2) operating the compressor 102 under the condition where closing an equalizer valve 107, where opening supply valves 104a, 104b and exhaust valves 104c, 104d of purge generation process side adsorption cylinders 105a, 105b, and where closing supply valves 104a, 104b of purge exhaustion process side adsorption cylinders 105a, 105b and opening exhaust valves 104c, 104d thereof, and (3) stopping the compressor 102 under the condition where opening all of the supply valves 104a, 104b and the exhaust valves 104c, 104d. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an oxygen concentrator for separating and using oxygen from the atmosphere.

  In recent years, the number of patients suffering from chronic respiratory diseases such as pulmonary emphysema, pulmonary tuberculosis sequelae and chronic bronchitis tends to increase. As a treatment method for such patients, oxygen inhalation therapy for inhaling high concentration oxygen is performed. Oxygen inhalation therapy is a treatment method in which the diseased patient is inhaled with oxygen gas or oxygen-enriched gas. Examples of the supply source of therapeutic oxygen gas or oxygen-enriched gas include the use of high-pressure oxygen cylinders, liquid oxygen cylinders, oxygen concentrators, etc., which can withstand long-term continuous use and are easy to use. For this reason, cases of using oxygen concentrators are increasing.

  The oxygen concentrator is an apparatus that can separate and concentrate oxygen in the air. As such an oxygen concentrator, a pressure fluctuation adsorption type oxygen concentrator in which an adsorbent capable of selectively adsorbing nitrogen in the air is filled in an adsorption cylinder is widely used from the viewpoint that high concentration oxygen of 90% or more can be obtained. Known and used. Such an apparatus usually supplies compressed air from a compressor to a plurality of adsorbent beds filled with an adsorbent that selectively adsorbs nitrogen, adsorbs nitrogen by applying pressure to the inside of the adsorbent bed, It is an apparatus that obtains high concentration oxygen by repeating an adsorption step for obtaining high concentration oxygen and a desorption step for desorbing nitrogen by depressurizing the inside of the adsorption bed. The pressure fluctuation adsorption method includes the PSA (Pressure Swing Adsorption) method for reducing the desorption process to atmospheric pressure, and the VPSA (Vacuum Pressure Swing Adsorption) for reducing the adsorption cylinder to a vacuum pressure using a compressor in order to increase the regeneration efficiency of the adsorbent. ) And is used as a medical oxygen concentrator.

Japanese Patent Laid-Open No. 2003-79735 Japanese Patent Laid-Open No. 2003-235982 JP 2000-281315 A JP 2008-228970 A

  Such an apparatus normally adsorbs nitrogen by supplying compressed air from a compressor to one or a plurality of adsorption beds filled with an adsorbent that selectively adsorbs nitrogen to pressurize the inside of the adsorption bed. This is an apparatus for obtaining high concentration oxygen by repeating an adsorption process for obtaining unadsorbed oxygen and a desorption process for desorbing and regenerating the adsorbed nitrogen by depressurizing the inside of the adsorption bed.

  Such a device is basically used regardless of whether the patient is eating or drinking or going to bed, and may be used continuously throughout the day, particularly in the case of severe respiratory disease patients. In many cases, a device is installed beside a patient, and noise and vibration generated from such a device may directly enter the ears of the patient, the patient's family, etc. and cause discomfort. Especially when sleeping, the influence of noise is large, and there is a concern that the patient or the family of the patient may be disturbed and adversely affect mental health. The largest noise and vibration generating element of the pressure fluctuation adsorption type oxygen concentrator is a compressor.

  Various measures have been taken for medical oxygen concentrators to reduce compressor noise and prevent vibration. For example, as a method for reducing noise generated by the compressor itself, Japanese Patent Laid-Open No. 2003-79735 describes an oxygen concentrator equipped with a low noise helical compressor. As a countermeasure for silencing noise, Japanese Patent Laid-Open No. 2003-235982 describes an oxygen concentrator equipped with a resonance silencer on an intake line that sends air to a compressor. Furthermore, in Japanese Patent Laid-Open No. 2000-281315, among the means in the housing, the means that is the source of vibration and the means that is affected by the vibration are individually arranged in the air by a vibration isolating member. Thus, an oxygen concentrating device characterized in that it is held elastically is disclosed.

  In addition to the above-mentioned hardware noise and anti-vibration measures, the operation sequence at the time of stopping the VPSA type oxygen concentrator was improved as a software response. JP 2008-228970 A discloses a device stop command. After receiving the signal, the pressure equalizing valve is opened, and the control to stop the compressor drive when the pressure in the suction cylinder falls below the specified pressure can be controlled to suppress vibration when the compressor stops. Has been.

  Thus, by reducing the load applied to the compressor, it is possible to prevent the compressor from generating noise and vibration when the apparatus is stopped. For this purpose, an operation for lowering the pressure in the adsorption cylinder when the apparatus is stopped is required, but in order to maintain long-term oxygen concentration performance, an operation for regenerating the adsorbent when the apparatus is stopped is also required. However, in the pressure fluctuation adsorption method, while one of the adsorption cylinders is pressurized to generate oxygen, the adsorbent is regenerated by evacuating and purging oxygen in the other adsorption cylinder. Oxygen is continuously generated by switching the flow path. Therefore, with respect to the adsorbent of any one of the adsorption cylinders, the apparatus stops in a state where nitrogen and moisture in the atmosphere are adsorbed. Moreover, the condensed water condensed in the middle of the piping may remain as it is.

  The present invention suppresses the load on the compressor when the apparatus is stopped, suppresses the generation of noise and vibration, suppresses the moisture absorption deterioration of the adsorbent after the apparatus is stopped, and uses the adsorbed water accumulated in the piping system and the condensed water in the piping. An oxygen concentrator having a function of reliably discharging to the outside is provided.

  The present invention provides the following oxygen concentrator. That is, the present invention includes a plurality of adsorption cylinders filled with an adsorbent capable of selectively adsorbing nitrogen rather than oxygen, a compressor that supplies pressurized air to the adsorption cylinder, and an adsorption cylinder downstream of the adsorption cylinder. A pressure equalizing valve for equalizing pressure, a supply valve for connecting a flow path between the compressor and each adsorption cylinder on the upstream side of the adsorption cylinder, and an exhaust valve for connecting a flow path between each adsorption cylinder and the exhaust pipe. An adsorption process for supplying pressurized air to extract concentrated oxygen, a desorption process for evacuating the adsorption cylinder after completion of the adsorption process to regenerate the adsorbent, and a desorption process for opening the pressure equalizing valve from the adsorption process side adsorption cylinder In the pressure fluctuation adsorption type oxygen concentrator equipped with a control means for repeating the purge process for introducing the adsorbent into the side adsorption cylinder and purging the adsorbent and the pressure equalizing process for communicating between the adsorption cylinders at a predetermined timing, the control means stops the apparatus. Sometimes all of the supply valve and the exhaust valve Providing an oxygen concentrator, characterized in that in the opened state is a means to perform a control of stopping the compressor.

The present invention also provides an oxygen concentrator, which is a means for controlling such a control means to lower the speed of the compressor in a stepwise manner when the apparatus is stopped.
According to the present invention, the adsorption cylinder includes two adsorption cylinders, and the control means performs opening / closing control of the flow path switching means and the pressure equalizing valve, whereby an adsorption process, a purge generation process, A steady-state sequence is performed in which the pressure equalization process, desorption process, purge exhaust process, and pressure equalization process are alternately switched between the desorption process, purge exhaust process, pressure equalization process, adsorption process, purge generation process, and pressure equalization process for the other adsorption cylinder. When the operation stop signal of the apparatus is recognized, (1) the operation is performed in a steady sequence until the end of the purge generation process or the end of the purge exhaust process, and (2) the pressure equalization valve is closed and the purge generation process side Open the supply valve and the exhaust valve of the adsorption cylinder, and operate the compressor with the supply valve of the adsorption cylinder on the purge exhaust process side closed and the exhaust valve open, and (3) the supply valve and the exhaust All valves opened Providing an oxygen concentrator, characterized in that in stopping the compressor, it is successively performed means controls the step from that (1) (3).
Further, the present invention provides an oxygen concentrator, which is a means for controlling such a control means to operate in a state where the rotational speed of the compressor is lower than the rotational speed in the steady sequence at the time of step (2).

  When the oxygen concentrator of the present invention receives the stop signal of the apparatus by turning off the operation switch, the operation is continued until the purge process of the normal operation sequence is completed, so that the adsorbent of the adsorption cylinder of the purge exhaust process side adsorption cylinder is maintained. Exhaust the adsorbed moisture completely. By closing the pressure equalizing valve and opening the supply valve and exhaust valve to the purge generation process side adsorption cylinder, the purge generation process side adsorption cylinder is evacuated to exhaust the adsorbed water, and the purge exhaust process side adsorption cylinder supply valve is closed. In addition, by maintaining the exhaust valve in an open state, exhaust is performed until the pressure in the adsorption cylinder becomes atmospheric pressure. During this time, by reducing the compressor speed, the exhaust efficiency is increased and the load on the compressor is reduced. Finally, all the supply valves and exhaust valves are opened, and the compressor is operated to remove condensed water in the piping. Drain everything, lower the pressure in the cylinder, and stop the compressor. Thereby, the load of the compressor when the apparatus is stopped can be suppressed, and the generation of noise and vibration can be suppressed.

The flowchart of the oxygen concentration apparatus of this invention. The operation | movement figure of the completion | finish sequence of the oxygen concentrator of this invention.

  An embodiment of the oxygen concentrator of the present invention will be described with reference to the following drawings. FIG. 1 is a schematic apparatus configuration diagram illustrating a two-cylinder PSA type pressure fluctuation adsorption type oxygen concentrator as an embodiment of the present invention.

  The oxygen concentrator of the present invention includes a compressor 102 that supplies raw air, adsorption cylinders 105a and 105b that are filled with an adsorbent that selectively adsorbs nitrogen over oxygen, and a switching valve that switches between adsorption and desorption processes (supply valve, exhaust valve) ) 104 and a pressure equalizing valve 107, and the oxygen gas separated and generated from the raw air is adjusted to a predetermined flow rate by the flow rate setting device 110 and then supplied to the user using the cannula 115.

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

  The oxygen gas is extracted by adsorbing cylinder 105 filled with an adsorbent such as sodium 5A type, 13X type, or Li-X type molecular sieve zeolite that selectively adsorbs nitrogen molecules rather than oxygen molecules. On the other hand, while the target adsorption cylinders 105a and 105b are sequentially switched by the switching valve 104, the raw material air is pressurized and supplied from the compressor 102, and about 77% of nitrogen gas contained in the raw material air in the adsorption cylinder 105 is supplied. Selectively remove by adsorption. The adsorbing cylinder 105 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 two-cylinder or multi-cylinder type adsorption cylinder.

  Further, as the compressor 102, 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. Further, the power source of the electric motor that drives the compressor 102 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 108 via check valves 106a and 106b provided so as not to flow back to the adsorption cylinder 105.
The nitrogen molecules adsorbed on the adsorbent must be desorbed from the adsorbent in order to adsorb nitrogen gas again from the newly introduced raw material air. For this purpose, the adsorption cylinder in the pressurized state is connected to the exhaust line by the exhaust valves 104c and 104d and switched to the atmosphere open state, and the nitrogen molecules adsorbed in the pressurized state are desorbed to regenerate the adsorbent. Further, in this desorption process, in order to increase the desorption efficiency, the oxygen-enriched gas is caused to flow back as a purge gas from the product end side of the adsorption cylinder during the adsorption process via the pressure equalizing valve 107.

  Oxygen-enriched gas is produced from the raw air and stored in the product tank 108. The oxygen-concentrated gas stored in the product tank 108 contains high-concentration oxygen gas, for example, 95%, and the supply flow rate and pressure are controlled by the flow rate setting means 110 such as the pressure regulating valve 109 and the control valve. , Supplied to the humidifier 113, and humidified oxygen is supplied to the patient.

  Such a humidifier 113 includes a moisture permeable membrane module having a moisture permeable membrane, and takes in moisture from external air and supplies it to dry oxygen-enriched air, or a bubbling humidifier using water Alternatively, a surface evaporation humidifier can be used.

  The flow rate and oxygen concentration of the oxygen-enriched gas supplied to the user are detected by an ultrasonic oxygen concentration / flow rate sensor 112, the rotation speed of the compressor 102, the opening / closing time of the flow path switching valve 104, and the opening degree of the control valve 110 It is also possible to control oxygen production by feedback control.

  In the PSA-type oxygen concentrator, when one adsorption cylinder 105a is performing an adsorption process, the other adsorption cylinder 105b performs a desorption process, and the adsorption process and the desorption process are sequentially switched in reverse phase, Is generated continuously. In order to increase the regeneration efficiency, a purge process (purge generation process, purge exhaust process) in which a part of oxygen generated in the adsorption process flows to the desorption process side adsorption cylinder via the pressure equalizing valve 107, after the completion of the adsorption process / purge generation process Incorporates a pressure equalization process that connects the adsorption cylinder and the adsorption cylinder after completion of the desorption process and purge exhaust process, and collects energy by pressure transfer. Adsorption process, purge generation process, pressure equalization process, desorption of one adsorption cylinder 105a The process, purge exhaust process, and pressure equalization process are efficiently performed by performing a steady sequence that alternately switches the desorption process, purge exhaust process, pressure equalization process, adsorption process, purge generation process, and pressure equalization process for the other adsorption cylinder. Can produce oxygen.

  When stopping the oxygen concentrator device, the adsorption bed must be stopped in any of the operation sequence of the adsorption process, purge generation process, pressure equalization process, desorption process, purge exhaust process, and pressure equalization process. become. From the viewpoint of regeneration of the adsorbent, it is most efficient to stop the apparatus after the desorption process and the purge exhaust process are completed and the nitrogen molecules in the adsorbent are completely removed. However, in the other adsorption cylinder, since the operation sequence is switched in the reverse phase state, it is always completed in the purge generation process in which oxygen is generated while purging. It is in an adsorbed state. Furthermore, one of the two adsorption cylinders is in a state of maximum pressure after the purge generation process is completed, and the other is in a state of minimum pressure of substantially atmospheric pressure after the purge exhaust process is completed. When the compressor is stopped in this state, a large load is applied, and a large vibration and noise are generated. Further, when the pressure equalizing valve is opened to reduce the pressure in the adsorption cylinder, gas flows from the adsorption cylinder on the purge generation process side into the adsorption cylinder in which the adsorbent regeneration after the purge exhaust process is completed.

  In the oxygen concentrator of the present invention, when the apparatus is stopped, the pressure equalizing valve 107 is closed, and the compressor 102 is stopped with all the solenoid valves of the supply valves 104a and 104b and the exhaust valves 104c and 104d being the flow path switching means opened. Operation control means is provided.

When the device stop signal is recognized during device operation, the following steps (1) to (3), that is,
(1) Operate in a steady sequence until the end of the purge generation process or the end of the purge exhaust process,
(2) Close the pressure equalizing valve, open the supply valve and the exhaust valve of the purge generation process side adsorption cylinder, close the supply valve of the purge exhaust process side adsorption cylinder, and open the exhaust valve. Drive
(3) Stop the compressor with all the supply valves and the exhaust valves open.
The control is sequentially performed.

Specifically, the supply valves 104a and 104b, the exhaust valves 104c and 104d, and the pressure equalizing valve 107 shown in FIG. 2 are controlled to open and close and the rotation speed of the compressor 102 is controlled.
Even if the stop switch is pressed during any of the adsorption process, purge generation process, pressure equalization process, desorption process, purge exhaust process, and pressure equalization process during steady operation, the next purge is performed as the end sequence (1). The operation is performed until the generation process or the purge exhaust process. As a result, regeneration of the adsorbent is always completed in one of the adsorption cylinders (adsorption cylinder 105b).

  Next, by closing the pressure equalizing valve 107 that was opened in the purge process, the gas flow into the adsorption cylinder 105b that has been regenerated is shut off, and the exhaust valve 105c on the adsorption cylinder 105a side that was performing nitrogen adsorption and oxygen generation is opened. Thus, decompression regeneration of the adsorption cylinder 105a starts. During this time, the compressor 102 is driven and thus receives supply air. However, since the exhaust valve 104c is open, nitrogen, oxygen, and moisture adsorbed by the adsorption cylinder 105a are desorbed and exhausted from the exhaust valve 104c according to the pressure difference. Condensed water collected in the piping is also blown out of the system by the pressurized air from the compressor and exhausted. At this time, exhaust efficiency can be increased by reducing the rotation speed of the compressor 102 to about 1/2. Since the exhaust valve 104d of the adsorption cylinder 105b is open, the residual pressure can be exhausted to near atmospheric pressure.

Finally, by opening all of the supply valves 104a and 104b and the exhaust valves 104c and 104d of the flow path switching valve 104, all the condensed water remaining in the connecting pipe between the compressor and the adsorption cylinder 105a and the adsorption cylinder 105b is exhausted. I can do it.
By performing such an end sequence, it is possible to regenerate the adsorbent in the adsorption cylinders 105a and 105b and exhaust the residual pressure, and to discharge all the moisture in the adsorbent and the pipe. By performing this process, the internal pressure of the adsorption cylinder decreases to near atmospheric pressure, so when the compressor 102 is stopped, the pressure load on the compressor drive unit can be minimized, and vibration and noise at the time of stop can be suppressed. I can do it.

  In this apparatus, compared with the case where the compressor is stopped at the maximum internal pressure of the adsorption cylinder 105a immediately after the purge process is finished, the vibration when the compressor is stopped after the completion sequence (1) to (3) is about 2 / 3 and noise is also reduced by 10%. In step (2), the compressor speed can be reduced to about 1/2 by reducing the compressor speed in two stages by reducing the speed of the compressor to 1/2 compared to the steady sequence. .

  The oxygen concentrator of the present invention is used as a medical oxygen concentrator as an oxygen supply source for oxygen inhalation therapy for patients suffering from respiratory organ diseases such as asthma, emphysema, and chronic bronchitis. In particular, the present invention provides an oxygen concentrator capable of suppressing the regeneration and moisture absorption deterioration of an adsorbent while suppressing vibration and noise when the apparatus is stopped, and ensuring the stability of long-term operation.

101 Intake silencer
102 Compressor
103 Compressor box
104 Channel switching valve
104a Supply valve a
104b Supply valve b
104c Exhaust valve c
104d Exhaust valve d
105a Adsorption cylinder a
105b Adsorption cylinder b
106a, 106b Check valve
107 pressure equalizing valve
108 Product tank
109 Pressure regulator
110 Flow rate setting device
111 Filter
112 Oxygen concentration / oxygen flow sensor
113 humidifier
114 filters
115 cannula
116 Humidifier attachment sensor
117 Exhaust silencer
118 Cooling fan
119 Pressure sensor
120 relief valve

Claims (4)

A plurality of adsorption cylinders filled with an adsorbent capable of selectively adsorbing nitrogen rather than oxygen, a compressor for supplying pressurized air to the adsorption cylinder, and a pressure equalizing valve for equalizing pressure between the adsorption cylinders downstream of the adsorption cylinder A supply valve for connecting the flow path between the compressor and each adsorption cylinder upstream of the adsorption cylinder, and an exhaust valve for connecting the flow path between each adsorption cylinder and the exhaust pipe, and supplying pressurized air to the adsorption cylinder The adsorption process for extracting concentrated oxygen, the desorption process for depressurizing the adsorption cylinder after completion of the adsorption process and regenerating the adsorbent, and introducing the concentrated oxygen from the adsorption process side adsorption cylinder into the desorption process side adsorption cylinder by opening the pressure equalizing valve In the pressure fluctuation adsorption type oxygen concentrator equipped with a control means for repeating a purge process for purging the adsorbent and a pressure equalizing process for communicating between the respective adsorption cylinders at a predetermined timing,
The oxygen concentrating apparatus, wherein the control means is a means for performing control to stop the compressor while all the supply valve and the exhaust valve are open when the apparatus is stopped.   2. The oxygen concentrating apparatus according to claim 1, wherein the control means is a means for performing control to stop the apparatus by decreasing the rotational speed of the compressor stepwise when the apparatus is stopped. The adsorption cylinder consists of two adsorption cylinders,
The control means performs opening / closing control of the flow path switching means and the pressure equalizing valve, thereby performing an adsorption process, a purge generation process, a pressure equalization process, a desorption process, a purge exhaust process, and a pressure equalization process for one adsorption cylinder. A means for performing a steady sequence of alternately switching the desorption process, purge exhaust process, pressure equalization process, adsorption process, purge generation process, pressure equalization process for the other adsorption cylinder,
When the operation stop signal of the device is recognized,
(1) Operate in a steady sequence until the end of the purge generation process or the end of the purge exhaust process,
(2) The pressure equalizing valve is closed, the supply valve and the exhaust valve of the purge generation process side adsorption cylinder are opened, and the supply valve of the purge exhaust process side adsorption cylinder is closed and the exhaust valve is opened. Drive
(3) Stop the compressor with all the supply valves and the exhaust valves open.
3. The oxygen concentrator according to claim 2, wherein the oxygen concentrator is a means for sequentially performing control.   The oxygen concentrator according to claim 3, wherein the control means is a means for controlling the compressor to operate in a state in which the rotational speed of the compressor is lower than the rotational speed in the steady sequence at the time of the step (2).

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