JPH08268701A - Oxygen concentrator - Google Patents

Abstract

PURPOSE: To provide a pressure-swing adsorption-type oxygen concentrator having stabilized performance by combining specified flow rate setting means. CONSTITUTION: This pressure-swing adsorption-type oxygen concentrator is provided with an adsorption tower 1 packed with an adsorbent 10 adsorbing nitrogen in preference to oxygen, an air compressing means 4 to send air to the tower 1, a vessel means 2 to transiently store concd. gaseous oxygen from the tower 1 and a supply means (duct means 23 and others) to use the concd. gaseous oxygen, and the following constitution is added. Namely, the flow rate setter 22 is provided to the duct means on the downstream side of the vessel means 2. The setter consists of a means to set the flow rate of the concd. gaseous oxygen to be used and a means to set the purge amt., both means are furnished with plural openings having a different resistance to flow and are the orifice-type flow rate setters capable of being used with the openings selected in accordance with the flow rate. The supply means is connected to the downstream side of the flow rate setter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for supplying a respiratory gas containing oxygen at a concentration higher than that of air, including an oxygen concentrator for separating oxygen-concentrated gas from the atmosphere for use. More specifically, it is a pressure fluctuation adsorption type oxygen concentrator, which is easier to perform when using a gas having a high oxygen concentration for chest disease (for example, 40% oxygen concentration) for respiration. The present invention provides an improved oxygen concentrating device that can supply an oxygen enriched gas to a user by various operations.

[0002]

2. Description of the Related Art In a pressure fluctuation adsorption type oxygen concentrator, the oxygen concentration is generally maintained at about 90%, and the required oxygen amount is adjusted by adjusting and changing the flow rate in a breathing gas supply means. For patients using a medical oxygen concentrator, if the required oxygen amount is small, the flow rate is 0.1 to 0.5.
It may be about 1 liter / minute, and may be about 4 to 6 liter / minute if it is large.

On the other hand, a membrane type oxygen concentrator using an oxygen separation membrane generally has an oxygen concentration of about 40%. These may be used properly depending on the patient's condition (medical condition, adult or dwarf, etc.). The membrane oxygen concentrators that have been put into practical use are currently about 40% in the mainstream.

It is known that the adsorption-type oxygen concentrator can change the oxygen concentration by changing the cycle time of adsorption and desorption, changing the capacity of the air supply means, and changing the product gas flow rate.

For example, Japanese Patent Laid-Open Publication No. 6-315533 discloses a medical oxygen supply method for supplying oxygen-enriched air generated by a pressure swing adsorption (PSA) method. The method for supplying medical oxygen, characterized in that the total amount of the oxygenated air is kept constant and the oxygen concentration in the oxygen-enriched air is maintained at a predetermined concentration even when the supply amount fluctuates. Is disclosed. In addition, in Japanese Patent Laid-Open No. 61-155201 and Japanese Patent Laid-Open No. 61-155205, which relate to a membrane type oxygen concentrator, which is often compared with an adsorption type oxygen concentrator, the flow rate of the oxygen concentrated gas supplied to the user is also described. It is disclosed that a control valve for purging the excess oxygen-enriched gas is provided on the upstream side of the meter to control the purge amount, and both of them are operated at substantially constant flow rates.

As a method specifically described in Japanese Patent Application Laid-Open No. 6-315533, after setting the concentration and the outflow amount of the oxygen-enriched gas obtained by the pressure fluctuation adsorption operation at the opening degree of the main valve 21, etc., Flow meter 23 again
It is intended to set the flow rate by adjusting the opening degree of the relief valve 22 while checking the flow rate. However, it is often difficult in practice to make the sum of the supply amount and the relief amount to the user constant only by operating the relief valve 22 side. There is a high possibility that it is necessary to perform the operation of the main valve 21 each time, or to provide a control valve or the like in the supply passage to the user side. As a result, it tends to be difficult to stably supply the oxygen-enriched gas with a constant concentration to the user.

[0007]

In such conventional pressure fluctuation adsorption type oxygen concentrators, it is often difficult to surely set the concentration and flow rate of the oxygen concentrated gas supplied to the user by a simple operation. It was Further, in the pressure fluctuation adsorption type oxygen concentrators up to now, even if the characteristics of the adsorbent change due to deterioration or the like, it is difficult to correct the concentration and flow rate of the oxygen concentrated gas supplied to the user. Furthermore, in the conventional pressure fluctuation adsorption type oxygen concentrator, even when the flow rate of the oxygen concentrated gas supplied to the user is low, the operation is performed in the same adsorption / desorption cycle as when the flow rate is high, etc. In many cases, the power consumption of the compressor used was constant.

The present invention is intended to solve the problems in the conventional pressure fluctuation adsorption type oxygen concentrator.

[0009]

The inventor of the present invention has conducted extensive studies in order to solve the above problems in the pressure fluctuation adsorption type oxygen concentrator, and as a result, it is effective to combine a unique flow rate setting means. The present invention has been discovered and has reached the present invention.

That is, according to the present invention, an adsorption tower filled with an adsorbent that preferentially adsorbs nitrogen over oxygen, an air compression means for sending air to the adsorption tower, and an oxygen-enriched gas from the adsorption tower are temporarily supplied. In a pressure fluctuation adsorption type oxygen concentrating device equipped with a container means for storing the oxygen-concentrated gas and a supply means for supplying the oxygen-concentrated gas, the flow rate of the oxygen-concentrated gas to be used for the conduit means on the downstream side of the container means is changed. A flow rate setting means for setting and a purge amount setting means for setting a purge amount are provided, and both the use flow rate setting means and the purge amount setting means are provided with a plurality of openings having different flow resistances and an opening corresponding to the flow rate. It is an orifice type flow rate setting device which can be used by selecting a part, and provides an oxygen concentrating device characterized in that the supply means is connected to a downstream side of the use flow rate setting device. .

In the apparatus of the present invention, the used flow rate setting means and the purge amount setting means are integrated so that both openings corresponding to respective flow rates can be selected by the same operation. An oxygen concentrator, which is a

Further, in the apparatus of the present invention, oxygen concentration detecting means for measuring the concentration of the oxygen-enriched gas, and adsorption when the oxygen concentration deviating from a predetermined width determined in advance is adsorbed,
An oxygen concentrator having a feedback control means for changing the desorption cycle time to keep the oxygen concentration within the range is included.

Further, in the apparatus of the present invention, the number of the adsorption tower is one, and the air compression means can be used for decompression / desorption of the adsorption tower, and oxygen for use is used. An oxygen concentrator having control means for setting the desorption time corresponding to the flow rate of the concentrated gas is included.

The present invention will be described in more detail below with reference to the drawings as necessary. In the present invention,
The number of adsorption towers is preferably 1 or 2, and particularly preferably 1.

FIG. 1 shows an example of a preferred embodiment of the oxygen concentrator of the present invention. In the figure, the adsorbent bed 1 is filled with an adsorbent 10 such as a molecular sieve 5A that is more likely to adsorb nitrogen than oxygen, and the compressor 4 equipped with a relief valve 25 is a flow passage switching valve. A pipette is connected to the adsorption bed 1 via a poppet type valve 5, and a surge tank 2 is further connected to the adsorption bed 1 via a pipe via an automatic opening / closing valve 12. The flow path switching valve 5 is provided with an intake conduit having an intake muffler and the like and an exhaust conduit having an exhaust muffler and the like. Further, the surge tank 2 is provided with a conduit for taking out oxygen-enriched air provided with a pressure regulating valve 19 and the like.

A flow rate setter 22 is also connected to this conduit, which is also an ON-OFF valve having no flow rate adjusting function, an automatic opening / closing valve 18, a sterilization filter 20, and a purging conduit 24.
It is practically preferable that the humidifier 7 and the nasal cannula (not shown) are provided. Further, the pressure detection means 21 detects the pressure on the upstream side of the flow rate setting device 22 and transmits information to a means (not shown) that issues an alarm when an abnormality in the pressure occurs. In addition, the conduit means 23 and the nasal cannula (not shown) and the like provided therein generally form the oxygen-concentrated gas supply means referred to in the present invention.

Here, the flow rate setting device 22 has a use flow rate setting means for setting the flow rate of the oxygen-enriched gas to be used and a purge amount setting means for setting the purge amount, and the use flow rate setting means and the purge Both of the quantity setting means are orifice type flow rate setting devices which are provided with a plurality of openings having different flow resistances of gas due to different opening areas so that the openings corresponding to the flow rate can be selected and used. .

As an example of the operation mode of the oxygen concentrator of FIG. 1, the valve 5 as shown in FIG.
Compressed air is introduced into the adsorption bed 1 via the compressor 4 to adsorb nitrogen, and the resulting oxygen-enriched gas is stored in the surge tank 2 via the conduit 13. The oxygen-enriched gas stored in the surge tank 2 is pressure-regulated by the pressure regulating valve 19, sterilized by the sterilization filter 20, set to a predetermined use flow rate and purge flow rate by the flow rate setting device 22, and the humidifier 7 And is supplied to a patient having a respiratory disease through a nasal cannula (not shown) connected to the conduit 23. After continuing adsorption for a predetermined time, the valve 12 is closed and the valve 5 is switched to use the compressor 4 as a vacuum pump to reduce the pressure in the adsorption bed 1 to perform desorption. After desorption for a predetermined time, the valve 5 was switched to introduce pressurized air into the adsorption bed 1, and further the valve 12 was opened to flow the oxygen-enriched gas back from the surge tank 2 to re-add the adsorption bed. After pressurizing, the adsorption step is carried out while continuously introducing pressurized air into the adsorption bed 1. Thereafter, these steps are sequentially repeated.

Further, if necessary, the surge tank 2
By installing a product tank through the check valve on the downstream side of
In the adsorption bed by opening the valve 12 at a time slightly earlier than the time when the compressor 4 is switched from the vacuum pump function to the compression function and opening the valve 12 to flow the oxygen-enriched gas back into the adsorption bed 1 from the surge tank 2. It is desirable that the oxygen can be repressurized in a state where the oxygen concentration is higher, and the oxygen-concentrated gas having a predetermined concentration can be obtained even if the adsorption pressure is generally slightly lowered. By performing the rinsing process in this manner, the refining effect can be enhanced, and the operating pressure can be reduced to reduce the power consumption of the compressor.

In FIG. 1, the blower 6 is mainly used to flow cooling air for cooling the compressor 4.

FIG. 2 shows the oxygen concentrator of the present invention in which the used flow rate setting means and the purge amount setting means are integrated, and both openings are selected by the same operation corresponding to each flow rate. It is an example of what is made possible.

In FIG. 2, reference numeral 31 is an inflow portion of the oxygen-enriched gas to which the upstream conduit is connected. An orifice-type purge flow rate setting unit 33 includes a plurality of openings having different opening areas, such as the opening 32, so that the openings can be selected and used according to the purge amount. 35 is the opening 3
This is an orifice type flow rate setting unit that is provided with a plurality of openings having different opening areas, such as 4, so that the openings can be selected and used according to the flow rate of oxygen-enriched gas used.
As shown in FIG. 2, the purge flow rate setting unit 33 and the use flow rate setting unit 34 are integrated.

Reference numeral 36 is a lead-out portion for discharging the oxygen-enriched gas to be purged, and its downstream side is open to the atmosphere. Reference numeral 37 is a derivation unit for the oxygen-enriched gas to be supplied to the user, and a humidifier, a nasal cannula, or the like is connected to the downstream side thereof as required. Reference numeral 38 denotes a rotary shaft for setting a desired use flow rate and a desired purge flow rate by the same rotation operation of both the purge flow rate setting unit 33 and the use flow rate setting unit 34 which are integrated. A knob (not shown) for facilitating the operation is further attached to the left end portion thereof.

Further, 40 is a display plate for displaying the flow rate set by the used flow rate setting unit 35. 41
When the rotating shaft 38 is rotated, the opening selected from the purging opening 32 and the like matches the opening 42 through which the gas to be purged passes, and the opening selected from the used gas opening 34 and the like. The part is a positioning member for fixing at a predetermined position so that the part fits into the opening 43 through which the gas to be supplied to the user passes.

In the oxygen concentrator shown in FIG. 1, it is desirable to use the one shown in FIG. 2 as the flow rate setting device 22. In the device of FIG. 1, the valve 5 and the solenoid valve 1
Opening and closing of Nos. 2 and 18 are controlled by a valve control means (not shown) to perform pressure fluctuation adsorption in a predetermined adsorption / desorption cycle. For example, the oxygen concentration of 40%, 60%, etc. Gas is obtained via conduit 23.

In the apparatus of the present invention, it is preferable that the withdrawal amount, that is, the use flow rate and the purge flow rate are determined in advance, and the concentration is determined by changing the cycle time of adsorption and desorption.

For example, in FIG. 1, the combination of the flow rate used by the flow rate setting device 22 and the purge flow rate is selected in advance so that the oxygen concentration obtained from the conduit 23 falls within a predetermined range, and then the adsorption / desorption cycle is performed. It is desirable to set. The combination of the flow rate used by the flow rate setter 22 and the purge flow rate may be such that the sum of both flow rates falls within a predetermined range, but the sum is changed as necessary. You can leave it.

In the apparatus shown in FIG. 1, for example, the pressure regulating valve 1
9 or an oxygen concentration detecting means (not shown) for measuring the concentration of the oxygen-enriched gas is provided somewhere in the middle of the flow rate setting device 22 to detect an oxygen concentration deviating from a predetermined width. Further, it is desirable to provide a valve control means with a feedback function for changing the cycle time of adsorption and desorption to keep the concentration within the range. A specific example of the valve control means is a microcomputer. As a result, even if the oxygen concentration of the obtained concentrated gas changes due to, for example, changes in the temperature and humidity of the atmosphere or deterioration of the adsorbent, the concentrated gas having a predetermined oxygen concentration can be stably supplied to the user.

In the apparatus of the present invention, the normal operating condition is that the adsorption time is, for example, 15 seconds or less, and the desorption time is also preferably 15 seconds or less. In the desorption process, the pressure of the adsorption tower is set to the vacuum side, preferably -0.3 kg / cm ² G
The following high vacuum is preferable.

In the apparatus of FIG. 1, it is desirable that the valve control means for controlling the adsorption / desorption cycle be provided with the function of setting the desorption time corresponding to the flow rate of the oxygen-enriched gas to be used.

The valve control means controls the opening / closing of the automatic opening / closing valve means in addition to performing the cycle of the adsorption process and the desorption process for pressure fluctuation adsorption, and the desorption is performed according to the above-mentioned set flow rate. The time can be set to a predetermined length. When the set value of the used flow rate is low, the desorption time can be set longer than when the set value is high. It is practically preferable that the time of the adsorption step is controlled to be substantially constant. As a specific example of the control means provided with means for setting the desorption time to a predetermined length, there is a microcomputer means in which a predetermined desorption time length corresponding to a flow rate set value is stored in a storage means in advance.

As the flow rate setting device, a device having a contact switch or a non-contact switch for generating a signal relating to the used flow rate setting value can be mentioned. Specific examples of the contactless switch include those using a photo sensor, a magnetic sensor, or the like. These are effective means for generating the flow rate set value as a signal.

By adopting such a system,
It is possible to reduce the power consumed by the compressor and the like.

[0034]

According to the apparatus of the present invention, it is possible to provide a PSA apparatus which is adapted to a predetermined oxygen concentration and which is improved so as to obtain stable performance.

[Brief description of drawings]

FIG. 1 is a schematic illustration of an oxygen concentrator of the present invention.

FIG. 2 is a view showing an example in which a used flow rate setting means and a purge amount setting means used in the oxygen concentrator of the present invention are integrated.

Claims (4)

[Claims] 1. An adsorption tower filled with an adsorbent that preferentially adsorbs nitrogen over oxygen, air compression means for sending air to the adsorption tower, and oxygen-enriched gas from the adsorption tower is temporarily stored. In a pressure fluctuation adsorption type oxygen concentrator equipped with a container means and a supply means for providing an oxygen concentrated gas for use,
The flow rate setting means for setting the flow rate of the oxygen-enriched gas to be used for the conduit means on the downstream side of the container means and the purge amount setting means for setting the purge amount, and the use flow rate setting means and the purge amount setting Both of the means are orifice type flow rate setting devices which are provided with a plurality of openings having different flow resistances so that the openings corresponding to the flow rate can be selected and used, and the supply means is provided on the downstream side of the used flow rate setting device. An oxygen concentrator, which is characterized by being connected. 2. The use flow rate setting means and the purge amount setting means are integrated so that both openings corresponding to respective flow rates can be selected by the same operation. Item 1. The oxygen concentrator of Item 1. 3. An oxygen concentration detecting means for measuring the concentration of oxygen-enriched gas, and when the oxygen concentration deviates from a predetermined width determined in advance, the oxygen concentration is changed by changing the cycle time of adsorption and desorption. The oxygen concentrating device according to claim 1, further comprising a feedback control means within the range. 4. The number of the adsorption tower is one, and the air compression means can be also used for decompression / desorption of the adsorption tower, which corresponds to the flow rate of the oxygen-enriched gas to be used. The oxygen concentrator according to claim 1, further comprising control means for setting the desorption time.