JP4313087B2 - Oxygen concentrator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oxygen concentrator and a control method therefor, and an oxygen concentrator capable of always supplying oxygen stably regardless of a set flow rate when performing treatment using a low-purity gas for breathing and a method therefor It relates to a control method.
[0002]
[Prior art]
The adsorption-type oxygen concentrator is an oxygen concentrator that feeds compressed air from the atmosphere into two adsorbing cylinders, adsorbs nitrogen by the adsorbent filled in the adsorbing cylinders, and absorbs only oxygen. The product is stored in a product tank, and the oxygen concentration is maintained at about 90% so that it can be appropriately supplied. Moreover, the patient who uses this oxygen concentrator can arbitrarily set the oxygen flow rate according to the symptom, for example, can be set to a continuous use state in the range of 0.1 to 5 liters per minute. By using this adsorption-type oxygen concentrating oxygen concentrating device, for example, oxygen with an oxygen concentration of 90% can be supplied to patients with chronic respiratory failure.
[0003]
On the other hand, a membrane oxygen concentrator using an oxygen separation membrane has been put into practical use. The model based on the principle of operation using this oxygen separation membrane can stably supply oxygen with an oxygen concentration of about 40%, so it is mainly used for the treatment of chronic lung diseases in infants that do not require high concentrations of oxygen. Yes.
[0004]
Further, a specific configuration for arbitrarily setting an oxygen flow rate and an oxygen concentration in an adsorption-type oxygen concentration apparatus has been proposed (Patent Document 1).
[0005]
[Patent Publication 1]
JP-A-6-315533 [Problems to be Solved by the Invention]
The adsorption-type oxygen concentrator described above is generally configured so that oxygen with an oxygen concentration of 40% can be continuously supplied stably for respiration. This oxygen concentration contributes to oxygen consumption. It is known to fluctuate with it. That is, when the oxygen flow rate is set large, the oxygen concentration decreases. Conversely, when the oxygen flow rate is set small, the oxygen concentration tends to increase. Furthermore, it is also affected by the temperature of the use environment.
[0006]
Accordingly, the present invention has been made in view of the above problems, regardless of the oxygen flow rate to be set, are intended to provide oxygen enriched equipment that the oxygen concentration can be maintained stably.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems and achieve the object, according to the present invention, compressed air is introduced into the interior from the inlet, nitrogen is adsorbed by the adsorbent filled therein, and oxygen is introduced from the outlet. Two suction cylinders to be discharged;
The compressed air is alternately introduced into the two adsorption cylinders, and when the adsorbent of one adsorption cylinder is saturated, nitrogen is discharged to the outside, and oxygen is extracted from the other adsorption cylinder. A switching valve piped to the inlet for switching,
An equal pressure valve that is piped between the outlet portions of the two adsorption cylinders and that is opened when one of the two adsorption cylinders reaches a predetermined internal pressure, thereby equalizing pressure;
An oxygen concentrator having piped oxygen supply means for sending out the discharged oxygen at an oxygen concentration of 40% and a set flow rate,
Concentration detection means connected to the oxygen supply means for detecting oxygen concentration;
When the oxygen concentration detected by the concentration detecting means is higher than 40%, the opening time of the equal pressure valve is lengthened according to the difference, and when lower than 40%, the opening of the equal pressure valve is increased according to the difference. is characterized by comprising a correction means for shortening the time.
Further, according to the present invention, the two adsorbing cylinders that introduce compressed air into the inside from the inlet portion, adsorb nitrogen by the adsorbent filled in the inside, and discharge oxygen from the outlet portion; To alternately introduce the compressed air into one adsorption cylinder and discharge nitrogen to the outside when the adsorbent in one adsorption cylinder is saturated and to switch out oxygen from the other adsorption cylinder Are connected between the switching valve connected to the inlet and the outlet of the two adsorption cylinders, and are opened when one of the two adsorption cylinders reaches a predetermined internal pressure. An oxygen concentrator comprising a pressure equalizing valve and an oxygen supply means for sending out the discharged oxygen at an arbitrarily set concentration and a set flow rate, wherein the oxygen concentration device is piped to the oxygen supply means, Concentration detection means for detecting oxygen concentration and the oxygen supply means When the oxygen concentration detected by the concentration detection means is higher than the set concentration, the open time of the equal pressure valve is lengthened according to the difference, and the setting is performed. When the concentration is lower than the concentration, correction means is provided for shortening the opening time of the equal pressure valve according to the difference.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.
[0016]
FIG. 1 is a piping diagram of an adsorption-type oxygen concentrating oxygen concentrating device that also serves as a block diagram. In the drawing, a thick solid line is a pipe 36, which shows air, oxygen, and nitrogen gas flow paths. A thin solid line indicates power supply or electric signal wiring.
[0017]
In this figure, the filter 33 that performs the initial filtration of the raw material air that flows into the pipe 36 is provided on the uppermost stream side of the pipe 36 in accordance with the flow direction of the raw material air and the flow direction of oxygen and nitrogen gas. Is connected. An intake filter 30 for further filtering fine dust is connected to the downstream side, and dust and dust are removed. An intake silencer 37 that silences the filtered raw material air is connected downstream of the intake filter 30, and the intake sound is silenced. A compressor 38 is connected to the downstream via a pipe 36. In the compressor 38, after the raw material air after filtration is introduced from the intake port, the compressed air is generated by being compressed in the two compression chambers. Then, it is sent out to the heat exchanger 40 piped downstream. The heat exchanger 40 is for cooling the compressed air whose temperature has been increased by the compressor 38, and the surface area is increased by making a metal pipe such as an aluminum pipe excellent in heat dissipation effect into a coil shape.
[0018]
The heat exchanger 40 is disposed near the compressor 38 and receives air from the pair of cooling fans 39 and 39 for directly sending external air introduced into the apparatus from the outside simultaneously with the compressor 38. Thus, the compressed air can be cooled by cooling the metal pipe. The compressed air that has been sufficiently cooled by the heat exchanger 40 is alternately supplied to the two first adsorption cylinders 43 and the inlet parts 43a and 44a of the second adsorption cylinders 44 that are piped downstream. Supplied. In order to supply the compressed air to the inlet portions of the adsorption cylinders 43 and 44 by alternately switching in this way, the flow paths are individually switched in two directions by electromagnetic valves that are electromagnetically driven. Switching valves 1, 2, 3, 4 are connected as shown.
[0019]
Specifically, four two-way valves 1, 2, 3, 4 are connected in a ring shape, pipes are drawn out from between adjacent valves, and a pipe 36 from the compressor 38 is connected to the switching valve 2. 3 is branched and connected, the pipe from the switching valve 1 is connected to the inlet 43a of the first adsorption cylinder 43, and the pipe from the switching valve 4 is connected to the inlet 44a of the second adsorption cylinder 44. Yes. The pipes from the switching valves 1 and 4 are connected to a silencer 42, and after the exhaust sound due to nitrogen and moisture released from the first adsorption cylinder 43 and the second adsorption cylinder 44 is reduced, the outside of the apparatus To exhaust.
[0020]
The first adsorbing cylinder 43 and the second adsorbing cylinder 44 are formed as cylinders further having outlet portions 43b and 44b on the upper side, are fixed in an upright state, and are granular as an adsorbent inside. Zeolite is packed, and by increasing the surface area, it can function as a catalyst carrier for nitrogen adsorption and oxygen generation. When one of these adsorption cylinders 43 and 44 is in the adsorption process, the other is applied to the regeneration of the adsorbent, and the switching valve is switched at a predetermined timing for each cycle as described later. To generate oxygen.
[0021]
On the other hand, one of the two adsorbing cylinders 43, 44 has a predetermined internal pressure when the compressed air is sent to the outlet portions 43b, 44b of the first adsorbing cylinder 43 and the second adsorption cylinder 44. An equal pressure valve 5 that is electromagnetically driven so as to be equalized with each other by being opened is provided. Further, throttle valves 6 are arranged and piped on the equal pressure valve 5. Or the equal pressure valve 5 is comprised as an electromagnetic solenoid valve which integrated the throttle valve.
[0022]
Further, a first check valve 46a is connected to the outlet portion 43b side of the first adsorption cylinder body 43, and a second check valve 46b is connected to the outlet portion 44b side of the second adsorption cylinder body 44 as shown in the figure. ing. Further, as shown in the figure, a pipe 36 is formed on the downstream side of each check valve so as to join at a joining point, and a pressure sensor 29 for detecting the pressure in each adsorption cylinder 43, 44 at this joining point. Are connected, and control described later is performed according to the output result from the pressure sensor 29.
[0023]
A product tank 47 for storing oxygen generated in each adsorption cylinder is connected to a pipe branched from the pressure sensor 29. Further, a pressure regulator 31 for adjusting the pressure for taking out oxygen is provided downstream of the product tank 47. A bacteria filter 32 for sterilizing bacteria is piped downstream of the pressure regulator 31 so that oxygen after sterilization is sent to a flow rate setting dial 27 which is a flow rate setting means. Further, as shown in the figure, the pipe 36 is branched from the middle, and oxygen is sent to the oxygen concentration sensor 48 which is a concentration detecting means, the oxygen concentration is detected, and the detection result is sent to a control board described later. Yes.
[0024]
Oxygen produced by the adsorption of nitrogen by the zeolite built in each adsorption cylinder causes the thirst if the patient inhales as it is because the humidity is almost zero. Therefore, a humidifier 20 that stores purified water is provided downstream, and humidity is given to oxygen in the process of passing the purified water as fine bubbles. A humidity sensor and a flow rate sensor 50, which is a flow rate detecting means, are connected to the downstream side of the humidifier 20, and it is constantly monitored that a set flow rate of oxygen is supplied to the oxygen outlet pipe 10. I am doing so. A coupler 11 is connected to the oxygen outlet pipe 10, and a nasal cannula 13 is connected via a tube 12 connected to the coupler 11. The patient sets the nasal cannula 13 in the nasal cavity and inhales oxygen.
[0025]
On the other hand, the above-described sensors and the two-way switching valves 1, 2, 3, 4 and the equal pressure valve 5 are connected to the control board 51 so that switching control of the solenoid valves described later is performed. Yes. The control board 51 is further connected to an inspection board 23 disposed at a position where inspection can be easily performed, and also receives power supply from a stabilized power supply 52 connected to the commercial power supply 19, and automatically when a power failure occurs. A secondary power source 34 such as a rechargeable battery that switches to a state in which power can be supplied is further connected.
[0026]
2 (a) to 2 (c) are diagrams schematically showing the switching valves 1, 2, 3, 4 and the equal pressure valve 5 for explaining the operation of FIG. In this figure, components that have already been described are denoted by the same reference numerals and description thereof is omitted. First, in FIG. 2A, the switching valves 1, 2, 3, 4 are switched to the illustrated state. The compressed air from the pipe 36 is supplied only to the first adsorption cylinder 43. At this time, the equal pressure valve 5 is closed, and a very small amount of oxygen is supplied to the second adsorption cylinder 44 through the throttle valve 6. In this state, nitrogen is adsorbed by the zeolite in the first adsorption cylinder 43, and oxygen is supplied into the product tank 47 through the check valve 46a. Eventually, the zeolite in the first adsorption cylinder 43 is saturated with nitrogen. This state is detected by the pressure sensor 29 as the internal pressure is increased.
[0027]
Then, as shown in FIG. 2 (b), the equal pressure valve 5 is opened, so that oxygen generated in the first adsorption cylinder 43 is sent to the outlet portion of the second adsorption cylinder 44, thereby incorporating the internal pressure valve 5. The zeolite is cleaned. Subsequently, by switching the switching valves 3 and 4 so that the pipe 36 is connected to the inlet portions of the adsorption cylinders 43 and 44, the left and right pressures are equalized, and then the switching valve 1 is silenced. By switching so as to connect the piping of 42 and the inlet of the first adsorption cylinder 43, the nitrogen accumulated in the first adsorption cylinder 43 is exhausted to the outside.
[0028]
Subsequently, in FIG. 2C, the switching valves 1, 2, 3, 4 are switched to the state shown in the figure to shift to a state in which compressed air from the pipe 36 is supplied only to the second adsorption cylinder 44. To do. At this time, the equal pressure valve 5 is closed, and a very small amount of oxygen is supplied to the first adsorption cylinder 43 through the throttle valve 6. In this state, nitrogen is adsorbed by the zeolite in the second adsorption cylinder 44, and oxygen is supplied into the product tank 47 through the check valve 46b. Eventually, the zeolite in the second adsorption cylinder 44 is saturated with nitrogen. This state is detected by the pressure sensor 29 when the internal pressure is increased.
[0029]
Then, as shown in FIG. 2 (d), when the equal pressure valve 5 is opened, oxygen generated in the second adsorption cylinder 44 is sent to the outlet portion of the first adsorption cylinder 43, thereby incorporating the internal pressure valve 5. The zeolite is cleaned. Subsequently, by switching the switching valves 1 and 2 so that the pipe 36 is connected to the inlet portions of the adsorption cylinders 43 and 44, the left and right pressures are equalized, and then the switching valve 4 is connected to the silencer 42. By switching so as to connect between the pipe and the inlet of the first adsorption cylinder 44, the nitrogen accumulated in the second adsorption cylinder 44 is exhausted to the outside. By repeating the above switching operation at a predetermined timing, continuous stable supply of oxygen is possible.
[0030]
FIG. 3 (a) is obtained by measuring the relationship between the oxygen flow rate and the oxygen concentration% when the cycle of FIG. 2 is executed in a state where the opening time of the equal pressure valve 5 is fixed in an environment at a temperature of 15 ° C. Is a chart.
[0031]
As can be seen from this chart, when the opening time of the equal pressure valve 5 is fixed at, for example, 2.15 seconds, the oxygen concentration becomes 40% when the flow rate of oxygen is set to 6 liters per minute using the setting dial 27. Was confirmed. In other words, when the maximum flow rate is set to 6 liters per minute, the opening time of the equal pressure valve 5 is set to 2.15 seconds so that the oxygen concentration can be maintained at 40%. However, if the opening time of the equal pressure valve 5 is fixed in this way, it has been confirmed that the oxygen concentration becomes 80% when the flow rate of oxygen is set to a smaller value, for example, 2 liters per minute. Furthermore, it was also measured that the oxygen concentration would be 90% when set to 1 liter per minute.
[0032]
Therefore, as shown in the chart of FIG. 3B, the opening time of the equal pressure valve 5 is lengthened as the flow rate set without fixing the opening time of the equal pressure valve 5 decreases, and the cycle of FIG. As a result of the execution, a relationship of 40% of the oxygen concentration was obtained according to the fluctuation of the oxygen flow rate.
[0033]
That is, as can be seen from the chart in FIG. 3B, when the flow rate of oxygen is set to 6 liters per minute when the opening time of the equal pressure valve 5 is 2.15 seconds, the oxygen concentration becomes 40%. It was confirmed that the oxygen concentration would be 42% by setting the opening time of the equal pressure valve 5 to a longer 3.54 seconds when the flow rate of 2 liters was set to be smaller, for example, 2 liters per minute, and was set to 1 liter per minute. Occasionally, it was also measured that the oxygen concentration was 42% by setting the opening time of the equal pressure valve 5 to 3.75 seconds. In this way, the flow rate (L / min) −the opening time interval of the equal pressure valve is tabulated and stored in the storage unit, and the opening time of the equal pressure valve 5 is corrected to be longer or shorter so that the oxygen during adsorption by zeolite is reduced. Since the ratio of nitrogen partial pressure can be changed, the oxygen concentration can be kept constant. In particular, an oxygen gas having a relatively high oxygen concentration flows in the initial stage when the equal pressure valve 5 is opened. However, as the opening time gradually increases, the oxygen gas having a lower concentration and mainly containing a large amount of nitrogen is on the opposite side. It is sent to the adsorption cylinder. As a result, the oxygen concentration generated inside the adsorption cylinder decreases. When the discharge flow rate decreases and the oxygen concentration rises, the open time of the equal pressure valve 5 is extended and the low concentration gas is sent to the opposite side, the generated oxygen concentration is lowered, and conversely, the oxygen concentration is lowered. In this case, it is possible to make the oxygen concentration substantially constant by shortening the opening time and increasing the oxygen concentration. As described above, the oxygen supply can be stably performed by correcting the opening time of the equal pressure valve 5.
[0034]
4 (a) is a timing chart of the whole after power-on of the apparatus, and FIG. 4 (b) is a timing showing the energization state of each switching valve 1, 2, 3, 4 and the equal pressure valve 5. It is a chart. FIG. 5 is a flowchart for explaining the operation executed in the control board 51 described above.
[0035]
Referring to FIGS. 4 and 5, the correction means is incorporated as a predetermined program in a circuit mounted with a microcomputer mounted on control board 51. When the oxygen concentration is equal to or higher than the set concentration, the pressure equalizing valve It functions to correct the opening time longer, and to correct the opening time of the equal pressure valve to be shorter than the set concentration. The correction means is performed every elapse of a predetermined time interval, temporarily stores the correction value of the correction performed last time, and uses the temporarily stored correction value for the next correction. Alternatively, the chart shown in FIG. 3B may be stored in advance in the storage element, and the time for opening the equal pressure valve may be determined from the relationship between the set flow rate and the oxygen concentration.
[0036]
Further referring to the block diagram of FIG. 1 in FIGS. 4 and 5, when the apparatus is turned on, the process proceeds to step S1 in the flowchart for explaining the operation of FIG. By repeating the operation d), oxygen is stored in the product tank 47. At this time, the opening time of the equal pressure valve 5 is fixed to 2.16 seconds, for example, so that oxygen having an oxygen concentration of 40% can be supplied at a flow rate of 6 liters per minute. If it is determined in step S2 that about 5 minutes have passed after that, the process proceeds to step S3, where the oxygen concentration sensor 48 and the flow rate sensor 50 detect the oxygen concentration and the oxygen flow rate. Will be sent. In the next step S4, after the detection by each sensor in step S3 waits for the elapse of a certain period of time, the detection error is eliminated, and then the process proceeds to step S5, where the oxygen concentration is detected again to determine whether or not the set concentration is reached. . If it is determined that the density is the set concentration, the process returns to step S3 and the detection loop is repeated again. The elapsed time in step S4 is determined with the set oxygen flow rate, because the oxygen concentration change time changes with the set flow rate.
[0037]
On the other hand, if it is determined in step S5 that the oxygen concentration deviates from the set oxygen concentration, the process proceeds to step S6, and the opening time of the equal pressure valve 5 is changed by the correcting means. Specifically, when the oxygen concentration is higher than the set oxygen concentration, the opening time of the equal pressure valve 5 is lengthened, and when the oxygen concentration is low, the opening time of the equal pressure valve 5 is shortened. This correction amount is determined by the deviation concentration amount where the oxygen concentration deviates from the set oxygen concentration. When the oxygen concentration greatly deviates, a large correction amount is added. Thereafter, the value corrected in step S7 is stored. When the device continues to operate in step S8, the process returns to step S3, and various sensors are read until a certain elapsed time.
[0038]
FIG. 6 is a chart showing the relationship between the flow rate and the oxygen concentration under use environments at different temperatures.
[0039]
As can be seen from this chart, when the flow rate of oxygen is set to 6 liters per minute using the setting dial 27 at an ambient temperature of 15 ° C. and the oxygen concentration is set to 40%, the lower temperature 5 It was also confirmed that the oxygen concentration was 40% at 6 liters per minute similarly at 35 ° C., which is as high as 35 ° C.
[0040]
However, for example, when the flow rate is set to 1 liter per minute at 5 ° C., the oxygen concentration increases to 50%, and when the flow rate is set to 1 liter per minute at 35 ° C., the oxygen concentration decreases to 32%. It was confirmed. This phenomenon is more susceptible to temperature as the equal pressure valve 5 is opened longer. Further, due to the temperature characteristics of the adsorbent, the oxygen gas partial pressure sent to increase the amount of adsorption at low temperatures increases. Seems to rise. The opposite is true at high temperatures.
[0041]
Therefore, by changing the time during which the equal pressure valve 5 is opened every predetermined time interval as described above so that the temperature detected by the temperature sensor 60 shown in FIG. It will be possible to prevent fluctuations.
[0042]
As described above, in order to perform the control by the correction means, it is only necessary to rewrite the program of the semiconductor element mounted on the control board 51, so that there is an advantage that no hardware change is required. In particular, the opening time of the equal pressure valve 5 is generated because the temperature varies depending on the temperature of the installation environment and varies depending on the influence of the raw material air that fluctuates due to the clogging of the filter and the amount of zeolite filled. It is ideal to detect and correct as appropriate. Thus, although feedback control for changing the opening time of the equal pressure valve 5 as described above is effective, the amount of change in oxygen concentration due to temperature change is calculated in advance from experiments, and the oxygen concentration is approximately 40% of the predetermined concentration. The temperature (° C.) − The flow rate (L / min) −the opening time (seconds) of the equal pressure valve may be tabulated as a parameter and stored in the storage unit.
[0043]
Note that the flow rate detection means is for the control board to read the set value of the flow rate setting device for determining the oxygen flow rate to be used as described above, but when the flow rate drops due to disturbance factors such as tube breakage. In addition, a flow sensor for measuring the actual flow rate may be provided.
[0044]
【The invention's effect】
As described above, according to the present invention, it is possible to provide an oxygen concentrator capable of stably maintaining an oxygen concentration regardless of the arbitrarily set oxygen flow rate.
[Brief description of the drawings]
FIG. 1 is a piping diagram of an adsorption-type oxygen concentrating oxygen concentrator that also serves as a block diagram according to an embodiment of the present invention.
2A to 2C are operation explanatory views schematically showing the switching valves 1, 2, 3, 4 and the equal pressure valve 5 of FIG.
FIG. 3 (a) shows the relationship between the oxygen flow rate and the oxygen concentration% when the cycle of FIG. 2 is executed in a state where the opening time of the equal pressure valve 5 is fixed, in an environment at a temperature of 15 ° C. (B) is a chart obtained by varying the opening time of the equal pressure valve 5 in accordance with the fluctuation of the oxygen flow rate.
4A is an overall timing chart after turning on the power to the apparatus, and FIG. 4B is a timing chart showing energization states of the switching valves 1, 2, 3, 4 and the equal pressure valve 5. FIG. .
FIG. 5 is a flowchart for explaining operations executed in the control board 51; It is.
FIG. 6 is a chart showing the relationship between the flow rate and oxygen concentration under operating environments at different temperatures.
[Explanation of symbols]
1, 2, 3, 4 Switching valve 5 Equal pressure valve 6 Throttle valve 10 Oxygen outlet pipe 11 Coupler 12 Tube 13 Nasal cannula 20 Humidifier 36 Pipe 37 Silencer 38 Compressor 39 Cooling fan 40 Heat exchanger 41 Switching valve 42 Silencer 43 First adsorption cylinder 44 Second adsorption cylinder 45 Equal pressure valves 46a, 46b Check valve 47 Product tank 48 Oxygen concentration sensor 50 Flow rate sensor 51 Control board

Claims (3)

Two adsorbing cylinders for introducing compressed air into the interior from the inlet, adsorbing nitrogen with the adsorbent filled therein, and discharging oxygen from the outlet;
The compressed air is alternately introduced into the two adsorption cylinders, and when the adsorbent of one adsorption cylinder is saturated, nitrogen is discharged to the outside, and oxygen is extracted from the other adsorption cylinder. A switching valve piped to the inlet for switching,
An equal pressure valve that is piped between the outlet portions of the two adsorption cylinders and that is opened when one of the two adsorption cylinders reaches a predetermined internal pressure, thereby equalizing pressure;
An oxygen concentrator having piped oxygen supply means for sending out the discharged oxygen at an oxygen concentration of 40% and a set flow rate,
Concentration detection means connected to the oxygen supply means for detecting oxygen concentration;
When the oxygen concentration detected by the concentration detection means is higher than 40%, the opening time of the equal pressure valve is lengthened according to the difference, and when it is lower than 40%, the opening of the equal pressure valve is increased according to the difference. And an oxygen concentrating device comprising a correcting means for shortening the time . Two adsorbing cylinders for introducing compressed air into the interior from the inlet, adsorbing nitrogen with the adsorbent filled therein, and discharging oxygen from the outlet;
The compressed air is alternately introduced into the two adsorption cylinders, and when the adsorbent of one adsorption cylinder is saturated, nitrogen is discharged to the outside, and oxygen is extracted from the other adsorption cylinder. A switching valve piped to the inlet for switching,
An equal pressure valve that is piped between the outlet portions of the two adsorption cylinders and that is opened when one of the two adsorption cylinders reaches a predetermined internal pressure, thereby equalizing pressure;
An oxygen concentrator having piped oxygen supply means for sending out the discharged oxygen at a set concentration and a set flow rate arbitrarily set,
Concentration detection means connected to the oxygen supply means for detecting oxygen concentration;
A flow rate detection means that is connected to the oxygen supply means and detects an oxygen flow rate;
When the oxygen concentration detected by the concentration detection means is higher than the set concentration, the open time of the equal pressure valve is lengthened according to the difference, and when the oxygen concentration is lower than the set concentration, the equal pressure valve according to the difference. Correction means for shortening the opening time of
An oxygen concentrator comprising: Comprising flow rate setting means for setting the set flow rate,
The oxygen concentrator according to claim 1 or 2, wherein the flow rate setting means can set a flow rate of 6 liters per minute as a maximum set flow rate.

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