JPH04279173A - Oxygen concentrator - Google Patents

Abstract

PURPOSE:To provide an oxygen concentrator by making a set flow rate hard to change as set by a flow rate setting means of an oxygen concentrate gas to be used in a pressure change absorbing type oxygen concentrator. CONSTITUTION:A surge tank means 3 is connected to an absorbing bed 1 and a product tank 2 is connected to the surge tank means 3 through a counterflow preventing means 8 to supply an oxygen concentrate gas for use from the product tank 2.

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 particularly, the present invention relates to a pressure fluctuation adsorption type oxygen concentrator, and provides an improved oxygen concentrator that can supply oxygen-enriched gas to a user at a more stable flow rate.

0002

[Prior Art] It is said that the number of patients suffering from respiratory system diseases such as asthma, emphysema, and chronic bronchitis has been increasing in recent years, and one of the most effective treatments for these diseases is There is an oxygen inhalation method.

[0003] The oxygen inhalation method involves having the patient inhale oxygen gas or oxygen-enriched air, and although oxygen gas cylinders have traditionally been used as the source of the oxygen gas or oxygen-enriched air, in recent years Since the development of oxygen concentrators that separate oxygen-enriched gas from the air, they have become increasingly popular due to their convenience in use and ease of maintenance.

[0004] There are two main types of oxygen concentrators: a membrane type oxygen concentrator that uses an oxygen selective permeability membrane, and an adsorption type oxygen concentrator that uses an adsorbent that can selectively adsorb nitrogen or oxygen.
Although there are various types, the present invention seeks to improve adsorption type oxygen concentrators.

[0005] The main type of adsorption type oxygen concentrator up to now is a pressure fluctuation adsorption type oxygen concentrator using a compressor. Such devices usually perform an adsorption process in which compressed air pressurized by a compressor is introduced into an adsorption bed filled with an adsorbent capable of selectively adsorbing nitrogen, and nitrogen is adsorbed under pressure to obtain an oxygen-enriched gas. An oxygen-enriched gas is obtained by alternately performing a desorption process in which desorption is performed 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. It is often used for rinsing for pressurization and desorption of adsorption beds.

[0006]

[Problems to be Solved by the Invention] As mentioned above, in the conventional pressure fluctuation adsorption type oxygen concentrator that uses a surge tank for oxygen-enriched gas downstream of the adsorption bed, it is difficult to rinse and re-desorb the adsorption bed. When the backflow of oxygen-enriched gas for pressurization becomes large, the internal pressure of the surge tank decreases, and the next pressure (upstream pressure) of the flow rate setting means placed downstream fluctuates, resulting in However, there is a problem in that the flow rate setting by the flow rate setting means tends to be inaccurate.

[0007]

[Means for Solving the Problems] As a result of intensive research aimed at solving the problems in the conventional oxygen concentrators, the present inventor has found that, on the upstream side of the flow rate setting means,
We have discovered that it is very effective to provide a product tank separate from the conventional surge tank, and have arrived at the present invention.

That is, the present invention provides an adsorption bed filled with an adsorbent capable of selectively adsorbing nitrogen over oxygen, compressor means for supplying compressed air to the adsorption bed, and oxygen concentration from the adsorption 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 making the oxygen enriched gas available for use, product is supplied to the surge tank means through a backflow prevention means. The present invention provides an oxygen concentrator characterized in that a tank is connected to the product tank means and the oxygen enriched gas supply means is connected to the product tank means.

The present invention includes a pressure fluctuation adsorption type oxygen concentrator in which the pressure fluctuation adsorption step includes a step in which the oxygen enriched gas stored in the surge tank means flows back into the adsorption bed;
and a flow rate setting in which the oxygen-enriched gas supply means is provided with a plurality of openings having different flow resistances for the oxygen-enriched gas, and the flow rate of the oxygen-enriched gas is set by switching the openings through which the oxygen-enriched gas flows. An oxygen concentrator equipped with means is included.

The present invention will be explained in more detail below.

The adsorbent used in the adsorption bed of the present invention may be any material as long as it can selectively adsorb nitrogen over oxygen, such as molecular sieve zeolite 5A, 13X, etc. Modified products are available.

[0012] The number of adsorption beds in the present invention may be either one or two or more, but in the case of a small-sized oxygen concentrator for medical use, the number of adsorption beds is preferably two or less. It is excellent in that it is easy to make the whole thing compact.

[0013] The oxygen concentrator of the present invention is configured such that oxygen enriched gas from the surge tank means flows back into the adsorption bed for rinsing during the adsorption bed repressurization process and desorption process. is desirable for achieving the effects of the invention.

Further, in the oxygen concentrating device of the present invention, the oxygen concentrating gas supply means is provided with a flow rate setting means for setting the supply amount of the oxygen concentrating gas according to the user's wishes or a doctor's prescription, for example. It is desirable to be present. In this case, the flow rate setting means may be a needle valve combined with a commonly used rotameter, but for example, as described in Japanese Patent Laid-Open No. 62-140026, a plurality of needle valves with different gas flow resistances may be used. It is better in practice to have an opening that allows the flow rate to be set by selecting the opening that matches the desired flow rate.

The product tank, which is a major feature of the present invention, is
It is provided downstream of the commonly used surge tank means for storing oxygen enriched gas and upstream of the flow rate setting means. Usually, a pressure reducing valve is used upstream of the flow rate setting means,
In that case, a product tank is provided upstream of the pressure reducing valve. By providing a product tank independent of the surge tank in this way, back mixing of oxygen-enriched gas can be prevented.
It becomes easier to obtain concentrated gas with higher concentration.

Between the product tank and the surge tank means,
Backflow prevention means are provided. As this backflow prevention means, a check valve with a simple structure and general use is usually preferably used, but for example, an automatic open/close valve such as a solenoid valve that is controlled to close only when backflow is likely to occur may be used. May be used.

Although the product tank and the surge tank may be separate, it is better to integrate the product tank and the surge tank by, for example, disposing a partition plate airtightly between one tank. is compact, which is preferable for practical use. In this case, the backflow prevention means may be provided in the conduit means provided on the outside of the tank, or may be provided in the partition plate.

[0018] The capacity of the product tank can be selected as appropriate, but it must be capable of ensuring a sufficient total amount of oxygen-enriched gas for use during periods other than the adsorption process. Particularly during that period, it is preferable to ensure that the product tank has enough volume to prevent the internal pressure of the product tank from decreasing to the extent that the flow rate at the flow rate setting means varies substantially. Filling such a product tank with an adsorbent capable of adsorbing oxygen to increase the actual capacity of the product tank is effective in making the product tank more compact.

The surge tank means in the present invention may be one that is commonly used, but the oxygen-enriched gas that flows into the adsorption bed near the beginning of the adsorption process and the oxygen-enriched gas that flows near the end of the adsorption process are substantially A structure that prevents mixing is superior in that it is easier to obtain gas with a high oxygen concentration. Examples of specific structures include thin tube-shaped tanks, cylindrical or box-shaped tanks with partition plates housed in them to lengthen the flow path, and multiple tanks in parallel with the adsorption bed. For example, a supply means may be connected to a tank into which the gas at the initial stage of adsorption flows, so that the oxygen-enriched gas flows into the tank at different stages of the adsorption process. In addition, in these surge tank means, at least the tank into which the oxygen-enriched gas flows in at the initial stage of adsorption, or the most downstream region of the surge tank, is filled with an adsorbent such as molecular sieve zeolite or molecular sieve carbon that can adsorb oxygen. Therefore, it is desirable to increase the oxygen concentration.

[0020] The use of the oxygen concentrator of the present invention is not particularly limited, and is suitable for medical use, for example, at home.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the oxygen concentrator of the present invention will be described in more detail below, using drawings as necessary.

FIG. 1 shows one example of a preferred embodiment of the oxygen concentrator of the present invention. In the figure, an adsorption bed 1 is filled with an adsorbent 10 such as molecular sieve 5A, which adsorbs nitrogen more easily than oxygen, and a compressor 4 equipped with a relief valve 25 is a two-channel type compressor 4 which is a flow path switching valve. It is connected to the adsorption bed 1 by a conduit through a poppet valve 5 , and the surge tank 3 is further connected to the adsorption bed 1 by a conduit through an automatic on-off valve 12 . Further, the flow path switching valve 5 is provided with an intake conduit including an intake muffler and the like, and an exhaust conduit including an exhaust muffler and the like. Further, a product tank 2 is connected to the surge tank 3 via a check valve 8. Further product tank 2
A conduit 23 for taking out oxygen-enriched air is provided with a pressure reducing valve 19 and the like. In addition, this conduit 23 further includes an automatic on-off valve 18, a sterilization filter 20, and a flow rate setting device 22.
, a humidifier 7, a nasal cannula (not shown), and the like are preferably provided from a practical standpoint. Further, the pressure detection means 21 detects the pressure on the upstream side of the flow rate setting device 22, and transmits information to means (not shown) for generating an alarm when an abnormality in the pressure occurs.

[0023] The conduit means 14 to 23 and their equipment usually constitute the oxygen enriched gas supply means referred to in the present invention. Further, the surge tank 3 is equipped with a number of partition plates 31 having openings 30, and the most downstream area is filled with an adsorbent such as molecular sieve 5A. Note that the surge tank 3 in FIG. 1 is schematically shown in a side view for convenience.

As an example of the operating mode of the oxygen concentrator shown in FIG. 1, pressurized air is introduced into the adsorption bed 1 by the compressor 4 through the valve 5 as shown in FIG. 1 with the solenoid valves 12 and 18 open. Nitrogen is adsorbed and the resulting oxygen-enriched gas is passed through conduit 1.
3 and is stored in the surge tank 3. The oxygen-enriched gas stored in the surge tank 3 flows into the product tank 2 via the check valve 8, is pressure regulated by the pressure reducing valve 19, is sterilized by the sterilizing filter 20, and is adjusted to a predetermined level by the flow rate setting device 22. The air is humidified by the humidifier 7 and supplied to patients with respiratory diseases through a nasal cannula connected to the conduit 23. After continuing adsorption for a predetermined period of time, the compressor 4 is turned on by closing the valve 12 and switching the valve 5.
is used as a vacuum pump to reduce the pressure inside the adsorption bed 1 and perform desorption. After attaching and detaching for a predetermined time, valve 5
By switching the switch to introduce pressurized air into the adsorption bed 1, and then opening the valve 12 to allow the oxygen-enriched gas to flow back from the surge tank 3, the adsorption bed is re-pressurized and the pressurized air continues to be adsorbed. The adsorption step is carried out while being introduced into bed 1. Note that even if the internal pressure of the surge tank becomes lower than that of the product tank during this repressurization, the pressure will not flow back from the product tank. These steps are then sequentially repeated.

Furthermore, by providing the product tank 2, the valve 12 is opened slightly earlier, about 1 second, than the time when the compressor 4 is switched from the vacuum pump function to the compression function, and the oxygen-enriched gas is transferred from the surge tank 3 to the adsorption bed. By rinsing with reverse flow to 1, the interior of the adsorption bed can be repressurized with a higher oxygen concentration, and an oxygen-enriched gas of a predetermined concentration can be obtained even if the adsorption pressure is generally slightly lowered. By performing the rinsing step in this manner, the purification effect can be enhanced, and the power consumption of the compressor can also be reduced by lowering the operating pressure.

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

FIGS. 2 and 3 schematically show an integrated surge tank and product tank used in the oxygen concentrator of the present invention. In FIG. 2, 42 is a surge tank, 43 is a product tank, 44 is a partition plate, 4
5 is a solenoid valve controlled by a separately provided control means, and 46 is a conduit. Note that a check valve may be used instead of the electromagnetic valve 45. In Figure 3, 52 is a surge tank;
53 represents a product tank, 54 a partition plate, and 55 a check valve. Note that in these figures, 13 and 14 represent the conduits 13 and 14 of FIG. 1, respectively.

[0028]

[Effects of the Invention] The oxygen concentrator of the present invention is improved so that a stable flow rate of oxygen-enriched gas can be supplied to the user. Furthermore, there is also the effect that oxygen-enriched gas of increased concentration can be more stably supplied to the user. In addition, in the apparatus of the present invention, the total volume of the surge tank and the product tank can be made to be about the same or smaller than that when only the conventional surge tank is used.

[Brief explanation of the drawing]

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

FIG. 2 is a schematic diagram of a preferred embodiment of the surge tank means and product tank used in the oxygen concentrator of the present invention.

FIG. 3 Same as FIG. 2.

Claims (3)

[Claims] 1. An adsorption bed filled with an adsorbent capable of selectively adsorbing nitrogen over oxygen, compressor means for supplying compressed air to the adsorption bed, and receiving oxygen-enriched gas from the adsorption bed. In a pressure fluctuation adsorption type oxygen concentrator equipped with a surge tank means for storing oxygen enriched gas and an oxygen enriched gas supply means for providing the oxygen enriched gas for use, a product tank is connected to the surge tank means via a backflow prevention means. An oxygen concentrating device characterized in that the oxygen concentrating gas supply means is connected to the product tank means. 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 oxygen-enriched gas supply means is provided with a plurality of openings having different flow resistances for the oxygen-enriched gas, and the flow rate of the oxygen-enriched gas is set by switching the openings through which the oxygen-enriched gas flows. 2. The oxygen concentrator according to claim 1, further comprising a flow rate setting means.