JPH05220224A - Oxygen condensing device - Google Patents

Abstract

PURPOSE:To provide a pressure fluctuation adsorption type oxygen condensing device using a surge tank on the downstream side of an adsorption floor and easily obtaining the product gas having high oxygen concentration even if the gas having low oxygen concentration enters the surge tank at the time near the completion of the adsorption process. CONSTITUTION:An adsorbent capable of adsorbing oxygen is partially filled in a surge tank means 3, the oxygen condensed gas is fed into a non-fill section 32, and the oxygen condensed gas is discharged from a fill section 33 and guided to a product means 2 via a backflow preventing means 36 in a pressure fluctuation adsorption type oxygen condensing device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen concentrator for separating and using an oxygen enriched gas from the atmosphere. More specifically, the present invention relates to a pressure fluctuation adsorption type oxygen concentrator, and to provide an improved oxygen concentrator capable of supplying an oxygen-concentrated gas to a user at a more stable concentration.

[0002]

2. Description of the Related Art Recently, it is said that the number of patients suffering from diseases of respiratory organs such as asthma, emphysema, chronic bronchitis and the like tends to increase. There is an oxygen inhalation method.

The oxygen inhalation method is a method of inhaling oxygen gas or oxygen-enriched air into a patient, and an oxygen gas cylinder has been conventionally used as a supply source of the oxygen gas or oxygen-enriched air. Since the development of oxygen concentrators that separate oxygen-enriched gas from the air, it has become increasingly popular due to its convenience in use and ease of maintenance.

The oxygen concentrator mainly comprises a membrane type oxygen concentrator using an oxygen selective permeable membrane and an adsorption type oxygen concentrator using an adsorbent capable of selectively adsorbing nitrogen or oxygen.
Although there are types, the present invention seeks to improve the adsorption type oxygen concentrator.

The main adsorption type oxygen concentrators so far used are pressure fluctuation adsorption type oxygen concentrators using a compressor. Such an apparatus is usually an adsorption step in which compressed air compressed by a compressor is introduced into an adsorption bed filled with an adsorbent capable of selectively adsorbing nitrogen to adsorb nitrogen in a pressurized state to obtain an oxygen-enriched gas. Then, the oxygen-enriched gas is obtained by alternately performing the desorption step of desorbing by reducing the internal pressure of the adsorption bed. In this case, a surge tank is used to temporarily store the oxygen-enriched gas from the adsorption bed, and the oxygen-enriched gas stored in the surge tank is caused to flow back to the adsorption bed to re-add the adsorption bed. Often used as a rinse for pressure and adsorption bed desorption.

[0006]

As described above, in the conventional pressure fluctuation adsorption type oxygen concentrator using the surge tank for oxygen enriched gas on the downstream side of the adsorption bed, near the end of the adsorption step in the adsorption bed. In the adsorbent bed, nitrogen is not sufficiently adsorbed and removed, and the oxygen-enriched gas containing a relatively large amount of nitrogen easily flows into the surge tank, and as a result, the oxygen concentration of the oxygen-enriched gas taken out from the surge tank for use is reduced. There was a problem that it was easy to get low.

[0007]

As a result of intensive research aimed at solving the problems in the conventional oxygen concentrators, the present inventor filled a part of a surge tank with an adsorbent and The present invention has been found out that it is very effective to provide a product tank different from the surge tank.

That is, the present invention is directed to an adsorbent bed filled with an adsorbent capable of selectively adsorbing nitrogen over oxygen, a compressor means for supplying compressed air to the adsorbent bed, and an oxygen concentration from the adsorbent bed. In a pressure fluctuation adsorption type oxygen concentrator equipped with a surge tank means for receiving and storing gas and an oxygen enriched gas supply means for using the oxygen enriched gas for use, at least a part of the internal space of the surge tank means Is filled with an adsorbent capable of adsorbing oxygen, and an inflow conduit means for allowing oxygen-enriched gas from the adsorption bed to flow into the surge tank means is opened in an adsorbent-free area of the surge tank means. An outflow conduit means for the oxygen enriched gas to flow out of the surge tank means is open in the adsorbent filling region of the surge tank means, Is connected to the product tank means via the check valve means, the product tank is connected to the surge tank means via the check valve means, and the oxygen-enriched gas supply means is connected to the product tank means. The present invention provides an oxygen concentrator characterized by the above.

According to the present invention, the pressure fluctuation adsorption type oxygen concentrator in which the pressure fluctuation adsorption step includes a step in which the oxygen concentrated gas stored in the surge tank means flows back to the adsorption bed;
And the adsorbent filling region is located below the surge tank means, and the opening of the outflow conduit means in the adsorbent filling region is such that the flow of gas within the adsorbent focused region is relative to the opening. It includes an oxygen concentrator located centrally in the lower layer so that it is symmetrical.

The present invention will be described in more detail below with reference to the drawings as necessary.

The adsorbent used in the adsorption bed of the present invention may be any adsorbent capable of selectively adsorbing nitrogen rather than oxygen, such as molecular sieve zeolite 5A, 13X or the like. Modified ones are given.

Further, the adsorption bed in the present invention may be either one unit or two or more units, but in the case of a small-sized oxygen concentrator for medical use, two or less units are preferable, and particularly one unit is the unit. It is easy to make the whole compact.

In the oxygen concentrator of the present invention, the oxygen enriched gas in the surge tank means flows back into the adsorbent bed due to rinsing in the repressurizing step and desorption step of the adsorbent bed. Is desirable for exerting the effect of the invention.

Further, in the oxygen concentrator of the present invention, the adsorbent filling area in the surge tank is located below, and the inlet conduit means for the oxygen enriched gas from the adsorption bed is opened at the upper end of the space above this. On the other hand, the outflow conduit means for outflowing the oxygen enriched gas from the surge tank ensures that the flow of the oxygen enriched gas in the adsorbent-filled region is uniform, i.e. the gas flow to the opening of the outflow conduit means. It is preferable to open the central portion of the lower layer of the adsorbent-filled region so that the symmetry is in order to exert the effect of the invention more effectively.

In the oxygen concentration apparatus of the present invention, the oxygen-concentrated gas supply means is provided with a flow rate setting means for setting the supply amount of the oxygen-concentrated gas in accordance with, for example, the user's request or the doctor's prescription. Is desirable. The flow rate setting means in this case may be a needle valve combined with a commonly used rotor meter, but a plurality of different flow resistances of gas as described in JP-A-62-140026, for example. It is practically better to provide an opening for each of the openings and select an opening suitable for the desired flow rate so that the flow rate can be set.

The oxygen concentrator of the present invention using such a flow rate setting means may be improved so that the oxygen concentrated gas can be supplied to the user in a stable state.

The surge tank means in which a partial space inside is filled with an adsorbent, which is a major feature of the present invention, is the surge tank means as in the preferred embodiment of the oxygen concentrator of the present invention shown in FIG. 3 comprises an adsorbent non-filled region 32 and an adsorbent filled region 33, and the opening 31 of the inflow conduit means 13 for the oxygen-enriched gas from the adsorption bed 1 to flow in is arranged in the adsorbent non-filled region. , Surge tank means 3
Outflow conduit means 35 for outflowing oxygen enriched gas from
The opening 34 is located in the adsorbent filling area.

As the adsorbent filled in the surge tank 3, at least oxygen can be adsorbed, such as molecular sieve zeolite or molecular sieve carbon, and nitrogen is selected over the oxygen filled in the adsorption bed 1. It may be an adsorbent such as a molecular sieve zeolite capable of adsorbing physically. In this case, the concentration of oxygen in this portion can be expected, which is more preferable. However, the main function of the adsorbent filled in the surge tank is to adsorb oxygen.

Generally, in the latter half of the adsorption process in the adsorption bed 1, the oxygen-concentrated gas discharged from the adsorption bed 1 has a lower oxygen concentration than that in the initial stage of the adsorption process, and it is disadvantageous to mix the entire surge tank. Therefore, as in the present invention, the latter half gas is retained in the space 32 of the surge tank 3 of FIG.
At the time of rinsing (the initial stage of the desorption process), the adsorption bed 1 is preferentially returned. From the beginning of the adsorption process to the middle-half oxygen-enriched gas,
It passes through the adsorbent filling area 33 in the surge tank 3, is further refined, and stays in the product tank 2, so that the concentration can be improved.

Regarding the ratio of the adsorbent-non-filled region and the adsorbent-filled region in the surge tank according to the present invention, the adsorbent-non-filled region is preferably in the range of 0.2 to 0.7 of the whole.

As shown in FIG. 1, at the open end in the adsorbent filling region 33 of the outflow conduit means 35 through which the oxygen-enriched gas from the surge tank 3 flows out, the gas flow in the adsorbent filling region 33 becomes more uniform. Thus, in other words, it is desirable to arrange the lower layer in the adsorbent-filled region 33, more preferably, substantially in the center of the lowermost part so as to be symmetrical about the opening end. Incidentally, it is desirable that the open end 31 of the inflow conduit means and the open end 34 of the outflow conduit means are provided with filter means.

The product tank means which is another feature of the present invention is provided on the downstream side of the surge tank means, and more preferably, a flow rate setting means is further provided on the downstream side. Normally, a pressure reducing valve is used on the upstream side of the flow rate setting means. In that case, a product tank is provided on the upstream side of the pressure reducing valve. By thus providing the product tank independently of the surge tank, it is possible to prevent back mixing of the oxygen-enriched gas, and it is easy to obtain a concentrated gas of higher concentration.

As shown in FIG. 1, the oxygen enriched gas outflow conduit means 35 between the product tank means 2 and the surge tank means 3 is provided with a backflow prevention means 36. As this backflow prevention means, a check valve having a simple structure and a general structure is usually preferably used, but for example, an automatic opening / closing valve such as a solenoid valve controlled to close only when a backflow is likely to occur is used. You may use.

The product tank 2 and the surge tank 3 may be separate, but, for example, as shown in FIG. 1, a partition plate 37 is airtightly arranged between the one tank and the product tank 2 and the surge tank 3 are provided. It is preferable for practical use that the whole is made compact because the whole is compact.

The capacity of the product tank means can be appropriately selected, but it is necessary that the total amount of the oxygen-enriched gas to be used during the period other than the adsorption step can be sufficiently secured.
In particular, during that period, it is preferable to secure a dose in the product tank such that the internal pressure of the product tank does not decrease to such a degree that the flow rate in the flow rate setting means changes substantially. By increasing the adsorbent capable of adsorbing oxygen into such a product tank, it is possible to substantially increase the holding dose of the product tank.
It is effective in making the product tank compact.

The apparatus of the present invention combines the surge tank with the product tank in a unique manner to make the gas flow in the outflow conduit means 35 shown in FIG. The adsorbent particles do not flow in the surge tank and the adsorbent particles are not damaged, and stable operation is possible. It should be noted that the device 12 of the present invention also includes a device capable of making the total volume of the surge tank and the product tank equal to or smaller than the case where only the conventional surge tank is used.

The use of the oxygen concentrator of the present invention is not particularly limited, and it is suitable for medical use such as home use.

[0028]

EXAMPLES Specific examples of the oxygen concentrator of the present invention will be described in more detail below with reference to the drawings, if necessary.

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 which 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 pipe is connected to the adsorption bed 1 via a poppet type valve 5, and a surge tank 3 is connected to the adsorption bed 1 via a pipe via an automatic opening / closing valve 12. Further, 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 product tank 2 is connected to the surge tank 3 via a check valve 36. Further, the product tank 2 is provided with a conduit 23 for taking out oxygen-enriched air provided with a pressure reducing valve 19 and the like.

The conduit 23 is further provided with an automatic opening / closing valve 1
8, sterilization filter 20, flow rate setting device 22, humidifier 7,
It is practically preferable that a nasal cannula (not shown) or the like is provided. The pressure detecting means 21 is a flow rate setting device 22.
The information is transmitted to a means (not shown) that detects the pressure on the upstream side of the device and issues an alarm when the pressure is abnormal. In addition, the conduit means 14 to the conduit means 23 and those provided therein form the oxygen enriched gas supply means usually referred to in the present invention.

The surge tank means 3 comprises an adsorbent non-filled area 32 and an adsorbent filled area 33, and the opening 31 of the inflow conduit means 13 for the oxygen-enriched gas from the adsorption bed 1 to enter is not filled with the adsorbent. The opening 34 of the outflow conduit means 35, through which the oxygen-enriched gas from the surge tank means 3 flows out, is arranged in the adsorbent filling area.

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 oxygen-enriched gas obtained is stored in the surge tank 3 via the conduit 13. The oxygen-enriched gas stored in the surge tank 3 flows into the product tank 2 through the check valve 8, is pressure-regulated by the pressure reducing valve 19, is sterilized by the sterilization filter 20, and is predetermined by the flow rate setting device 22. Is set to a flow rate of, is humidified by the humidifier 7, and is supplied to a patient or the like having a respiratory disease via a nasal cannula connected to the conduit 23. After adsorption is continued 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 period of time, the valve 5 is switched to introduce pressurized air into the adsorption bed 1, and further, the valve 12 is opened to reversely flow the oxygen-enriched gas from the surge tank 3 to re-add the adsorption bed. After pressing
Then, the adsorption step is carried out while introducing pressurized air into the adsorption bed 1. Even if the internal pressure of the surge tank is lower than that of the product tank during this repressurization, the surge current does not flow back from the product tank. Thereafter, these steps are sequentially repeated.

Further, by providing the product tank 2, the valve 12 is opened at a time slightly earlier than about 1 second from the time when the compressor 4 is switched from the vacuum pump function to the compression function, and the oxygen enriched gas is adsorbed from the surge tank 3 to the adsorption bed. By backflowing to 1 and rinsing, it is possible to re-pressurize the inside of the adsorption bed in a state where the oxygen concentration is higher, and it is possible to obtain an oxygen-concentrated gas of a predetermined concentration 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.

Note that, in FIG. 1, the blower 6 is mainly for flowing cooling air for cooling the compressor 4.

As a preferred embodiment of the apparatus of the present invention, the compressor 4 and the blower 6 are housed in a sound deadening box, and a partition plate having an opening is provided in the box to provide a chamber upstream of the cooling air flow. In addition, the blower 6 is arranged in the lower chamber, the compressor 4 is arranged in the downstream chamber, and the open end of the intake side conduit means of the flow path switching valve 5 is located in the chamber accommodating the blower. Incidentally, it is desirable that a filter is provided at the intake port for the cooling air of the apparatus.

In such a configuration, the flow of cooling air from the cooling blower-side chamber to the compressor-side chamber is one-way, and by arranging the compressor intake port in the blower-side chamber, the ambient air Clean air can be inhaled at a temperature close to the temperature. The temperature of the room on the compressor side easily rises due to heat radiation from the compressor, and introducing air from there to the intake port of the compressor may be detrimental to performance.

[0037]

The oxygen concentrator of the present invention also has the effect of more stably supplying the oxygen-concentrated gas having an increased concentration to the user.

[Brief description of drawings]

FIG. 1 is a schematic flow chart schematically showing a preferred embodiment of an oxygen concentrator of the present invention.

Claims (3)

[Claims] 1. An adsorbent bed filled with an adsorbent capable of selectively adsorbing nitrogen over oxygen, a compressor means for supplying compressed air to the adsorbent bed, and an oxygen-enriched gas from the adsorbent bed. Surge tank means for storing,
In a pressure fluctuation adsorption type oxygen concentrator equipped with an oxygen-enriched gas supply means for supplying an oxygen-enriched gas, an adsorbent capable of adsorbing at least oxygen is filled in a part of an internal space of the surge tank means. An inflow conduit means for allowing oxygen-enriched gas from the adsorption bed to flow into the surge tank means is opened in an adsorbent-free region of the surge tank means, and the oxygen-enriched gas flows out from the surge tank means. An outlet conduit means for opening in the adsorbent filling area of the surge tank means, the outlet conduit means being connected to the product tank means via a check valve means, wherein the oxygen concentration in the product tank means An oxygen concentrator, characterized in that a gas supply means is connected. 2. The oxygen concentrator according to claim 1, wherein the step of causing the oxygen-enriched gas stored in the surge tank means to flow back into the adsorption bed is included in the pressure fluctuation adsorption step. 3. The adsorbent filling area is located below the surge tank means, and the opening of the outflow conduit means in the adsorbent filling area is the flow of gas within the adsorbent filling area. The oxygen concentrator according to claim 1, wherein the oxygen concentrator is located in the center of the lower layer so as to be symmetrical with respect to the opening.