JP2013132359A - Oxygen concentrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxygen concentrator for safely treating high concentration oxygen stored in a tank.SOLUTION: The oxygen concentrator includes: ducts 101A, 101B for returning high concentration oxygen stored in a product tank 41 to sieve beds 33A, 33B; and discharge valves 102A, 102B for closing the ducts 101A, 101B when the oxygen concentrator 1 is used and opening the ducts 101A, 101B when the oxygen concentrator 1 is not used. Thus, when the oxygen concentrator 1 is not used, the high concentration oxygen stored in the product tank 41 is mixed with nitrogen inside the sieve beds 33A, 33B, so that the oxygen concentration is reduced. Consequently, the high concentration oxygen stored in the product tank 41 is safely treated.

Description

  The present invention relates to an oxygen concentrator that introduces air to produce high-concentration oxygen. In particular, the present invention relates to an oxygen concentrator having a tank for storing generated high-concentration oxygen.

  Some oxygen concentrators are used in home oxygen therapy (HOT) in which patients with respiratory diseases inhale oxygen at home. This type of oxygen concentrator is described in Patent Document 1, for example.

  The oxygen concentrator compresses indoor air taken in through a filter and an intake tank by a compressor. The oxygen concentrator passes this compressed air through a sieve bed (adsorption tower). The sieve bed is filled with an adsorbent (for example, zeolite) having a property of adsorbing nitrogen to pressurized air and desorbing nitrogen to decompressed air. With this configuration, the sheave bed generates high-concentration oxygen by separating nitrogen from the compressed air. The high concentration oxygen produced in this way is stored in a tank. The stored oxygen is subjected to a treatment such as humidification, and is supplied to the patient through the oxygen outlet and through the nasal cannula worn by the patient.

JP 2006-263441 A

  By the way, the high-concentration oxygen stored in the tank is kept stored in the tank as it is when the oxygen concentrator is not used, or is gradually discharged from the tank into the room via the oxygen outlet. Is done.

  Here, it is preferable that the high concentration oxygen stored in the tank should not remain in the tank at a high concentration when the oxygen concentrator is not used, considering an emergency such as a fire or transportation. it is conceivable that. However, if high-concentration oxygen is simply exhausted from the tank into the room, there may be a danger when there is a fire nearby.

  In spite of such a current situation, sufficient studies have not been made so far regarding proper handling of high-concentration oxygen in the tank when the oxygen concentrator is not used.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an oxygen concentrator that can appropriately (safely) handle high-concentration oxygen stored in a tank.

  One aspect of the oxygen concentrator of the present invention includes a sieve bed that generates high-concentration oxygen by separating nitrogen from compressed air, a tank that stores high-concentration oxygen generated by the sheave bed, and the tank And a pipe line connecting the sheave bed, and when the oxygen concentrator is used, the state of the pipe line is set so that the high concentration oxygen does not return from the tank to the sheave bed, and the oxygen concentrator And a control unit that sets the state of the pipe line to a state in which the high-concentration oxygen can be returned from the tank to the sheave bed when the is not used.

  According to the present invention, when the oxygen concentrator is not used, the high concentration oxygen stored in the tank is returned to the sheave bed and mixed with nitrogen, so that the oxygen concentration is lowered. As a result, the high concentration oxygen stored in the tank can be handled appropriately (safely).

The figure which shows schematic structure of the oxygen concentrator which concerns on one embodiment of this invention. The block diagram which shows schematic structure of the control system of the oxygen concentrator of embodiment

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a piping system of an oxygen concentrator according to an embodiment of the present invention. The oxygen concentrator 1 illustrated in FIG. 1 is a PSA (Pressure Swing Adsorption) type oxygen concentrator including an air intake unit 10, a compressor 20, a PSA unit 30, an oxygen storage unit 40, and an oxygen supply unit 50.

  The air intake unit 10 is a part that takes outside air that is raw material air into the housing, and includes an intake filter 11, a hepa filter 12, and the like. The intake filter 11 removes airborne particles such as dust and dust from the raw air introduced through the air intake port 13 provided in the housing. The hepa filter 12 removes fine particles that have not been removed by the intake filter 11.

  The compressor 20 compresses the raw air introduced through the air intake unit 10 to generate compressed air.

  It is desirable to dispose an expansion silencer (silencer) that exerts a silencing effect on the operation sound of the compressor 20 upstream of the compressor 20 (downstream of the hepa filter 12).

  The PSA unit 30 functions as a high concentration oxygen generation unit. The PSA unit 30 separates nitrogen from the compressed air generated by the compressor 20 to generate high-concentration oxygen, and sends this to the oxygen storage unit 40. The PSA unit 30 includes a flow path switching unit 31, an exhaust silencer 32, sheave beds (adsorption towers) 33A and 33B, a purge orifice 34, a pressure equalizing valve 35, check valves 36A and 36B, and the like.

  The flow path switching unit 31 is composed of a manifold (manifold) having four switching valves SV1 to SV4, and alternately sends the compressed air generated by the compressor 20 to the sheave beds 33A and 33B, and the sheave bed 33A. , 33B are alternately opened to atmospheric pressure to discharge nitrogen-enriched air.

  Specifically, in the flow path switching unit 31, the flow path from the compressor 20 toward the sheave bed 33A is opened by setting the switching valve SV1 to “open” and the switching valve SV2 to “closed”. The flow path from the sheave bed 33A toward the exhaust silencer 32 is closed. At the same time, in the flow path switching unit 31, the switching valve SV3 is "closed" and the switching valve SV4 is "opened", whereby the flow path from the compressor 20 toward the sheave bed 33B is closed, while the sheave bed 33B. To the exhaust silencer 32 is opened. In this case, compressed air generated by the compressor 20 is sent to the sheave bed 33A, and nitrogen-enriched air is released from the sheave bed 33B and exhausted through the exhaust silencer 32.

  Further, when the switching valves SV1 to SV4 are in the opposite state, the compressed air generated by the compressor 20 is sent to the sheave bed 33B, and nitrogen-enriched air is discharged from the sheave bed 33A and exhausted. The air is exhausted through the silencer 32. The open / close state of the switching valves SV1 to SV4 is switched at intervals of 10 seconds, for example.

  The exhaust silencer 32 is connected to an exhaust port (not shown) provided in the casing of the oxygen concentrator 1, and exhausts when the nitrogen-enriched air discharged from the sheave beds 33A and 33B is discharged to the outside of the casing. Mute the sound.

  The sieve beds 33 </ b> A and 33 </ b> B separate nitrogen from the compressed air sent via the flow path switching unit 31 to generate high-concentration oxygen. The sieve beds 33A and 33B are filled with an adsorbent such as zeolite having the property of adsorbing nitrogen faster than oxygen.

  When the flow path from the compressor 20 is opened by the flow path switching unit 31, the sheave beds 33A and 33B are pressurized by being fed with compressed air. At this time, in the sieve beds 33A and 33B, nitrogen and moisture are adsorbed and only oxygen passes, so that high-concentration oxygen is generated (adsorption process).

  The concentration of the high-concentration oxygen generated in the sieve beds 33A and 33B is adjusted to, for example, about 90%. Further, since zeolite adsorbs not only nitrogen but also moisture, the high-concentration oxygen produced in the sieve beds 33A and 33B is extremely dry (for example, humidity 0.1 to 0.2%).

  On the other hand, when the flow path to the exhaust silencer 32 is opened by the flow path switching unit 31, the sheave beds 33 </ b> A and 33 </ b> B are released to the atmospheric pressure and are in a reduced pressure state. At this time, nitrogen and moisture adsorbed on the zeolite are desorbed, nitrogen-enriched air is released from the sieve beds 33A and 33B, and exhausted through the exhaust silencer 32. Thereby, the adsorption capacity of the sheave beds 33A and 33B is regenerated (regeneration step).

  The sheave beds 33A and 33B are connected to the product tank 41 of the oxygen storage unit 40 via check valves 36A and 36B. The check valves 36A and 36B prevent the high concentration oxygen stored in the product tank 41 from flowing back to the sheave beds 33A and 33B.

  Further, the downstream side of the sheave beds 33A and 33B is connected by a pipe having a purge orifice 34. The high-concentration oxygen generated in one sheave bed 33A (or 33B) is sent to the oxygen storage section 40 via the check valve 36A (or 36B), and the other sheave bed 33B via the purge orifice 34. (Or 33A). A part of the generated high-concentration oxygen is sent to the other sheave bed 33B (or 33A), whereby the regeneration process of the sheave bed 33B (or 33A) is efficiently performed. The flow rate of high-concentration oxygen in each flow path is controlled by the orifice diameter of the purge orifice 34.

  Further, the downstream side of the sheave beds 33 </ b> A and 33 </ b> B is connected by a pipe having a pressure equalizing valve 35. When the sieve beds 33A and 33B in the regeneration process are switched to the adsorption process, if compressed air is allowed to flow in under reduced pressure (atmospheric pressure), the nitrogen adsorption efficiency is poor. Therefore, the pressure equalizing valve 35 is “open” at the time of switching, and the pressures in the sheave beds 33A and 33B are averaged.

  The oxygen storage unit 40 is a part that temporarily stores the high concentration oxygen generated by the PSA unit 30. The oxygen storage unit 40 includes a product tank 41, a pressure adjustment unit (pressure regulator) 42, an oxygen sensor 43, a pressure sensor 44, a flow rate adjustment unit 46, and the like.

  The product tank 41 is a container for storing high-concentration oxygen produced in the sheave beds 33A and 33B. Since the high concentration oxygen delivered from the sheave beds 33A and 33B is once stored in the product tank 41, the concentration fluctuation and pressure fluctuation of the high concentration oxygen are suppressed. Concentrated oxygen can be supplied.

  The pressure adjusting unit 42 adjusts the pressure of the high concentration oxygen to a constant pressure suitable for use in order to control the flow rate of the high concentration oxygen to be supplied. The pressure of the high-concentration oxygen stored in the product tank 41 varies not a little as long as there is an inflow to the product tank 41 or an outflow from the product tank 41. In this case, accurate flow rate control becomes difficult, and accurate concentration measurement by the oxygen sensor 43 becomes difficult. Considering this, the high-concentration oxygen is adjusted to a constant pressure by the pressure adjusting unit 42.

  The oxygen sensor 43 detects the concentration of high-concentration oxygen delivered from the pressure adjustment unit 42 at a predetermined interval (for example, 20 minutes) or continuously. As the oxygen sensor 43, for example, a zirconia type sensor or an ultrasonic sensor is suitable. Since the accurate measurement becomes difficult if the pressure of the high-concentration oxygen to be measured fluctuates, generally, the oxygen sensor 43 is connected to the downstream of the pressure adjustment unit 42 via the flow restriction orifice 45.

  The pressure sensor 44 detects the pressure of high-concentration oxygen stored in the product tank 41. Based on the detection result by the pressure sensor 44, it can be confirmed whether the pressure of the high concentration oxygen stored in the product tank 41 is maintained in a normal range.

  The flow rate adjusting unit 46 adjusts the flow rate of the high concentration oxygen sent from the pressure adjusting unit 42. As the flow rate adjusting unit 46, for example, an orifice type flow rate setting device having a plurality of orifices and selecting an orifice suitable for a desired flow rate or a needle valve type flow rate setting device is used. Can do.

  The oxygen supply unit 50 is a part that discharges the high-concentration oxygen sent from the oxygen storage unit 40 from the oxygen outlet 55. The oxygen supply unit 50 includes a bacterial filter 51, a pressure sensor 52, a flow restriction orifice 53, and a humidification unit 54.

  The bacteria filter 51 collects and disinfects bacteria contained in the high concentration oxygen in order to supply clean high concentration oxygen to the user.

  The pressure sensor 52 is a sensor for detecting the discharge pressure in the case of continuous use and the user's respiration in the case of the synchronous type, and is connected to the downstream side of the bacteria filter 51 via a flow restriction orifice 53. High concentration oxygen humidified by the humidifying unit 54 is supplied to the oxygen outlet 55. The humidified high concentration oxygen is supplied to the user through a nasal cannula or oxygen mask connected to the oxygen outlet 55.

  In addition to such a configuration, the oxygen concentrator 1 of the present embodiment is provided with pipe lines 101A and 101B for returning the high concentration oxygen stored in the product tank 41 to the sheave beds 33A and 33B. The conduits 101A and 101B are provided with discharge valves 102A and 102B, respectively.

  The discharge valves 102A and 102B are “closed” when the oxygen concentrator 1 is used, and are “open” when the oxygen concentrator 1 is not used. Thereby, when the oxygen concentrator 1 is used, high concentration oxygen is stored in the product tank 41, and when the oxygen concentrator 1 is not used, high concentration oxygen in the product tank 41 is discharged to the sheave beds 33A and 33B. (Returned).

  Here, “when the oxygen concentrator 1 is being used” means that the user performs an operation to turn on the power or start an operation in the operation unit of the oxygen concentrator 1, and the oxygen concentrator 1 is in operation. It is the state that is said. Conversely, “when the oxygen concentrator 1 is not being used” means that the user performs an operation to turn off the power or an operation to stop the operation at the operation unit of the oxygen concentrator 1, and the oxygen concentrator 1 stops operating. It is a state that is considered to be inside.

  In the oxygen concentrator 1 of the present embodiment, when the oxygen concentrator 1 is not used, the high concentration oxygen stored in the product tank 41 is returned to the sheave beds 33A and 33B, so that the inside of the product tank 41 The amount of high-concentration oxygen is reduced. Moreover, the high concentration oxygen returned to the sheave beds 33A and 33B is mixed with nitrogen in the sheave beds 33A and 33B, so that the oxygen concentration becomes low. As a result, the product tank 41 is safer than being stored in high concentration.

  Here, in order to reduce the oxygen concentration by mixing with nitrogen in the sieve beds 33A and 33B, the sieve bed containing a large amount of nitrogen immediately before the use is stopped, of the two sieve beds 33A and 33B. It is more preferable to return oxygen to a high concentration. In other words, as described above, the sieve beds 33A and 33B have an adsorption process for generating high-concentration oxygen by adsorbing nitrogen and moisture in a pressurized state in which compressed air is fed, and nitrogen through the exhaust silencer 32. Since the regeneration process in which the enriched air is discharged is alternately repeated, it is preferable to select which sheave bed 33A, 33B to return the high concentration oxygen to, based on what state the sheave bed 33A, 33B is. .

  For example, if the use is stopped before passing the midpoint between the adsorption process and the regeneration process, the sieve bed that has undergone the regeneration process will contain more nitrogen than the sieve bed that has undergone the adsorption process. Therefore, when the use is stopped, the discharge valve 102A of the pipe line 101A or the discharge valve 102B of the pipe line 101B connected to the sheave bed that has been performing the regeneration process is preferably opened. On the contrary, when the use is stopped after passing the intermediate point between the adsorption process and the regeneration process, the sheave bed that has been performing the adsorption process has more nitrogen than the sieve bed that has been performing the regeneration process. Since it is considered that many are included, when the use is stopped, the discharge valve 102A of the pipe 101A connected to the sheave bed that has been performing the adsorption process or the discharge valve 102B of the pipe 101B may be opened.

  However, it is not always necessary to return high-concentration oxygen only to the sieve bed containing a large amount of nitrogen, and high-concentration oxygen may be returned to both sheave beds 33A and 33B.

  By the way, if the pressure in the sheave beds 33A and 33B is higher than the pressure in the product tank 41, high concentration oxygen cannot flow into the sheave beds 33A and 33B even if the discharge valves 102A and 102B are opened. When stopping, in addition to opening the discharge valves 102A and 102B, the switching valves SV1 and SV3 provided between the sieve beds 33A and 33B and the compressor 20 are opened. It is preferable to reduce the pressure in 33A and 33B. Further, when the use is stopped, the pressure in the sheave beds 33A and 33B may be reduced by opening the switching valves SV2 and SV4. In short, the pipe line provided on the upstream side of the sheave beds 33A and 33B may be opened when the use is stopped. However, if the discharge pipe is kept open, the zeolite in the sieve beds 33A and 33B may deteriorate due to humidity. Therefore, after the pressure is reduced, the discharge pipe is returned to the closed state, and the zeolite in the sieve beds 33A and 33B is deteriorated. It is preferable to prevent.

  Further, a sheave bed 33A, 33B is connected to a discharge pipe different from the flow path switching unit 31 shown in FIG. 1, and when the use is stopped, the discharge pipe is set to “open” so that the sheave bed 33A, The inside of 33B may be depressurized. Also in this case, it is preferable to prevent the zeolite in the sieve beds 33A and 33B from being deteriorated by returning the discharge pipe to the closed state after the pressure reduction.

  In the configuration of the present embodiment, the high-concentration oxygen in the product tank 41 is mixed with nitrogen in the sheave beds 33A and 33B and discharged after the oxygen concentration is lowered. The remaining oxygen can be discharged safely compared to the case where the remaining oxygen is discharged directly from the product tank 41 or from the oxygen outlet 55.

  FIG. 2 is a diagram showing a schematic configuration of a control system of the oxygen concentrator according to the present embodiment.

  As shown in FIG. 2, the control unit 60 includes a CPU (Central Processing Unit) 61, a RAM (Random Access Memory) 62, a ROM (Read Only Memory) 63, and the like. The CPU 61 reads a program corresponding to the processing content from the ROM 63 and develops it in the RAM 62, and controls the operation of each block of the oxygen concentrator 1 in cooperation with the developed program.

  Specifically, the control unit 60 receives detection signals from the oxygen sensor 43 of the oxygen storage unit 40, the pressure sensor 52 of the oxygen supply unit 50, the temperature sensor 71 installed inside the housing, and other various sensors. Entered. In addition, an operation signal for instructing a set flow rate is input to the control unit 60 when, for example, a user sets a supply flow rate in the operation unit 81 having operation buttons and the like. When the user performs an operation for turning off the power of the oxygen concentrator 1 or an operation for stopping the operation of the oxygen concentrator 1 in the operation unit 81, an operation signal indicating the operation is input to the control unit 60. .

  Based on these input signals, the control unit 60 controls the number of rotations of the drive motor of the compressor 20, controls the open / close state and opening of the switching valves SV1 to SV4 of the flow path switching unit 31, and adjusts the flow rate. The adjustment flow rate by the part 46 is set. By such control, high concentration oxygen is supplied from the oxygen concentrator 1 at a set flow rate.

  Further, the control unit 60 closes the discharge valve 102 when the oxygen concentrator 1 is used, and opens the discharge valve 102 when the oxygen concentrator 1 is not used (as described above). One of the discharge valves 102A and 102B may be opened, or both the discharge valves 102A and 102B may be opened).

  In addition, the control unit 60 performs control related to display on the display unit 82 including a liquid crystal display (LCD) and a light emitting diode (LED), and control related to audio output from the speaker 83. . The display unit 82 and the speaker 83 are used when notifying the user of various types of information.

  Although not shown, the oxygen concentrator 1 is provided with an interface that can be connected to a communication network such as a wireless local area network (LAN) or Bluetooth (registered trademark) so that various data can be transmitted to and received from an external device. Also good.

  As described above, according to the present embodiment, the pipes 101A and 101B for returning the high concentration oxygen stored in the product tank 41 to the sheave beds 33A and 33B and the oxygen concentrator 1 are used. There is provided a control unit 60 that sometimes closes the pipes 101A and 101B and opens the pipes 101A and 101B when the oxygen concentrator 1 is not used.

  Thereby, when the oxygen concentrator 1 is not used, the high concentration oxygen stored in the product tank 41 is mixed with nitrogen in the sheave beds 33A and 33B, so that the oxygen concentration is lowered. As a result, the high concentration oxygen stored in the product tank 41 can be handled appropriately (safely).

  In the above-described embodiment, the case where the pipe lines 101A and 101B are provided and the high concentration oxygen stored in the product tank 41 is returned to the sheave beds 33A and 33B using the pipe lines 101A and 101B has been described. However, the configuration of the present invention is not limited to this. For example, without providing the pipe lines 101A and 101B, the pipe lines between the check valves 36A and 36B and the product tank 41, the pipe lines between the sheave beds 33A and 33B and the check valves 36A and 36B, The same configuration as that of the above-described embodiment can be performed by providing a pipe line for connecting the pipes and further providing a discharge valve for opening and closing the pipe line. Further, in place of the check valves 36A and 36B, an electromagnetic valve that can return the high concentration oxygen stored in the product tank 41 to the sheave beds 33A and 33B may be provided.

  In the above-described embodiment, the pipe lines 101A and 101B are closed when the oxygen concentrator 1 is used, and the pipe lines 101A and 101B are opened when the oxygen concentrator 1 is not used. However, the present invention is not limited to this, and when the oxygen concentrator 1 is not used, it is not always necessary to keep the conduits 101A and 101B open. For example, the open state may be maintained for a certain period of time and closed when the amount of high-concentration oxygen in the product tank 41 falls below a target value.

  In short, when the oxygen concentrator 1 is being used, the state of the pipeline is set so that high concentration oxygen does not return from the product tank 41 to the sheave beds 33A and 33B, and when the oxygen concentrator is not being used. What is necessary is just to set the state of a pipeline to the state which can return high concentration oxygen from the product tank 41 to the sheave beds 33A and 33B.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and can be changed without departing from the gist thereof.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Oxygen concentrator 10 Air intake part 20 Compressor 30 PSA part 31 Flow path switching part 32 Exhaust silencer 33A, 33B Sheave bed SV1-SV4 Switching valve 40 Oxygen storage part 41 Product tank 50 Oxygen supply part 60 Control part 101A, 101B Pipe line 102A, 102B discharge valve

Claims (4)

A sieve bed that produces high-concentration oxygen by separating nitrogen from compressed air,
A tank for storing high-concentration oxygen produced by the sieve bed;
A conduit connecting the tank and the sheave bed;
When the oxygen concentrator is used, the state of the pipeline is set so that the high-concentration oxygen does not return from the tank to the sheave bed, and when the oxygen concentrator is not used, the state of the pipeline A control unit that sets the high-concentration oxygen to a state in which the high-concentration oxygen can return from the tank to the sheave bed;
An oxygen concentrator comprising: In addition to setting the state of the conduit to a state in which the high-concentration oxygen can return from the tank to the sheave bed when the oxygen concentrator is not used, Open the pipeline provided on the upstream side of the bed,
The oxygen concentrator according to claim 1. The pipe line that is provided on the upstream side of the sheave bed and is in an open state is a pipe line that includes between the sheave bed and the compressor.
The oxygen concentrator according to claim 2. The pipe line that is provided on the upstream side of the sheave bed and is in an open state is a pipe line that includes between the sheave bed and the exhaust silencer.
The oxygen concentrator according to claim 2.

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