JPH06315534A - Oxygen concentrating device - Google Patents

Abstract

PURPOSE:To maintain adsorption performance stable over a long period of time in the pressure fluctuation adsorbing oxygen concentrating device. CONSTITUTION:The adsorption bed 1 of this PSA type oxygen concentrating device has perforated plates 7, 9 for regulating the flow of air at the top end and bottom end of an adsorbent packed part and the intermediate part of this adsorbent packed part has a member 12 for holding the particles of the adsorbent 11 for preventing mixing of the particles of the adsorbent 11. Further, one of the perforated plates 7, 9 at the top end and bottom end is provided with a spring for holding the perforated plates 7, 9 in the state of pressing these plates to the adsorbent side.

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 to inhale 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 an oxygen concentrator that separates 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 a selective oxygen 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 under pressure to obtain an oxygen-enriched gas. Then, the oxygen-concentrated 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 for pressure and rinse for desorption of the adsorbent bed.

[0006]

In the above-mentioned adsorption bed, the phenomenon in which the adsorbent particles in the adsorption bed slightly change their positions due to repeated adsorption / desorption steps and convection in the bed for a long time occurs. Seen. This is not preferable in order to use the adsorption bed stably and maintain the performance. In addition, this is one of the phenomena that must be avoided especially in an adsorption bed in which a plurality of types of adsorbents are packed in layers.

[0007]

As a result of intensive research aimed at solving the problems in the conventional oxygen concentrators, the present inventor has found that the method of filling the adsorbent in the adsorbent bed is used for the spring-loaded porous method. The present inventors have found that it is very effective to combine a plate and a member having fine apertures through which particles of an adsorbent do not pass, and arrived at the present invention.

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 swing adsorption (PSA) 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, the adsorbent bed has an adsorbent filling section. A perforated plate for rectifying the flow of air at the upper and lower ends of the adsorbent, and an adsorbent particle holding member for preventing admixture of adsorbent particles in the middle part of the adsorbent filling part, and the upper end The present invention provides an oxygen concentrator, characterized in that one of the lower part and the lower end of the perforated plate is provided with a spring means for holding the perforated plate in a state of being pressed against the adsorbent side.

In the apparatus of the present invention, the adsorption bed is one, and the compressor means functions as a compressor when supplying compressed air to the adsorption bed, and functions as a vacuum pump during the desorption process of the adsorption bed. An oxygen concentrator that is adapted to do so is included.

Further, in the apparatus of the present invention, the adsorbent particle holding member is positioned substantially perpendicular to the air flow in the adsorption bed, and does not substantially cause flow resistance of the air in the adsorption bed. Therefore, an oxygen concentrating device in which the adsorbent filling portion is divided into 2 to 4 regions is included.

Further, in the device of the present invention, at least a part of the internal space of the surge tank means is filled with an adsorbent capable of adsorbing oxygen, and the oxygen enriched gas from the adsorption bed is supplied to the surge tank means. Inflow conduit means for inflow is open in the adsorbent unfilled area of the surge tank means, and outflow conduit means for outflow of oxygen enriched gas from the surge tank means is adsorbent filled area of the surge tank means. An oxygen concentrator is included which is open at, the outlet conduit means is connected to the product tank means via a check valve means, and the oxygen tank gas supply means is connected to the product tank means.

Further, in the apparatus of the present invention, 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.

Further, in the apparatus of the present invention, 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 within the adsorbent filling area. An oxygen concentrator located in the center of the lower layer such that the gas flow is symmetrical with respect to the opening.

The oxygen concentrator of the present invention will be described in more detail below with reference to the drawings as needed.
Generally, in a pressure fluctuation type adsorption (PSA) apparatus, the position of the adsorbent packed in the adsorption bed may change according to the pressure fluctuation of the process. One-tower type P as described in JP-A-4-279173 and Japanese Patent Application No. 4-30693
This phenomenon is also observed in the SA device of the type that functions as a compression pump to ensure desorption.

This phenomenon is particularly remarkable in the conventionally used type shown in FIG. 1, and the packing density becomes high with the passage of time, and a space is formed at the upper part. In this case, the adsorbent convects inside the tower as if the water were convection due to a temperature difference (density difference). It can be said that these are fatal in the medical PSA type oxygen concentrator which requires a delicate adsorption zone formation. In order to improve these, there is also a type in which the upper part is spring-loaded. (Only the upper part of FIG. 2). However, even this cannot completely prevent the flow. This is because the flow is not uniform in the inflow method in the lower part of FIG. 1, and the flow of the particles of the adsorbent during adsorption and desorption cannot be avoided. Therefore, a structure that produces substantially only the axial flow component in the adsorption bed is preferable (see FIG. 3).

In the adsorbent bed of the present invention, a rapid temperature change partially occurs in the portion into which the compressed air flows. In other words, during desorption, the desorption is sufficiently carried out and heat is dissipated due to the endothermic reaction, resulting in a significant decrease in temperature. The temperature may drop 10 ° C or more from room temperature. In addition, during the adsorption, the inflowing air causes a rapid adsorption of nitrogen, so the temperature rises violently due to the exothermic reaction.

In the case of FIG. 1 showing a conventional adsorption bed, a complicated temperature distribution and temperature change occur around the inflow section. This indicates that the adsorbent has not been effectively used to increase the oxygen concentration. That is, the contact between the gas and the solid is not effectively performed.

By improving as shown in FIG. 2, a wide oxygen concentration up was obtained. These are especially necessary when downsizing the apparatus and downsizing the adsorption bed, and are necessary techniques for improving the productivity of the adsorbent.

In the case of continuous operation for a long time, in order to further prevent the flow of the adsorbent in the bed, the adsorption of the nonwoven fabric, wire mesh, etc. shown in FIG. 3 which is an example of the adsorption bed in the oxygen concentrator of the present invention. Adsorbent particle holding member 12 as agent flow prevention means
Is effective.

For example, in FIG. 3, the lowermost part is filled with an adsorbent which is relatively strong against moisture (humidity) in the air to supply air, and the upper part is filled with an adsorbent such as nitrogen and oxygen separation performance. For filling, for example, a nonwoven fabric or the like provided between them is effective.

The purpose of this non-woven fabric is merely to prevent the movement of the adsorbent particles, and it is sufficient as long as it has openings through which the particles do not pass. There is no need to specially fix it to the adsorption bed wall (for example, an aluminum cylinder), and it is sufficient to lay it in the middle when filling the adsorbent.

Therefore, as seen elsewhere, for example, in an industrial large-scale adsorption tower with a large diameter, the flow in the central portion of the tower is fast, so that the so-called redistribution is made in order to make the retention time uniform and the intermediate partition tower. There is also an example in which a structure that regulates the flow pattern is provided. It causes a flow in a direction perpendicular to the so-called flow direction (axial direction) and is fundamentally different from the adsorbent particle holding member of the present invention.

[0023]

INDUSTRIAL APPLICABILITY The oxygen concentrator of the present invention is excellent in that the position of each adsorbent particle in the adsorption bed is easily fixed, and the performance of the adsorbent can be stably maintained even during long-term continuous operation. Produce the effect.

[Brief description of drawings]

FIG. 1 is a schematic illustration of a conventional adsorption bed.

FIG. 2 is a schematic illustration of a conventional adsorption bed.

FIG. 3 is a schematic illustration of an adsorption bed in the oxygen concentrator of the present invention.

[Explanation of symbols]

 1 Adsorbent Bed 2 Compressed Air Inlet 3 Oxygen Concentrated Air Outlet 4 Lid 5 Adsorbent Holding Spring 6 Seal Packing 7,9 Perforated Plate 8,10 Nonwoven Fabric 11 Adsorbent 12 Adsorbent Particle Holding Member 13 Adsorbent Filling Port 14 Empty Space

Claims (6)

[Claims] 1. An adsorption bed filled with an adsorbent capable of selectively adsorbing nitrogen over oxygen, a compressor means for supplying compressed air to the adsorption bed, and an oxygen-enriched gas from the adsorption bed. Surge tank means for storing,
In a pressure fluctuation adsorption type oxygen concentrator equipped with an oxygen-concentrated gas supply means for providing an oxygen-concentrated gas for use, the adsorption bed is for rectifying the flow of air to the upper end and the lower end of the adsorbent filling section. A perforated plate is provided, and an adsorbent particle holding member is provided in the middle part of the adsorbent-filled portion to prevent adsorbent particles from mixing, and the perforated plate is adsorbed on one of the upper and lower end perforated plates. An oxygen concentrator, comprising spring means for holding the agent in a pressed state. 2. A single adsorbent bed, wherein the compressor means functions as a compressor when supplying compressed air to the adsorbent bed, and as a vacuum pump during the desorption process of the adsorbent bed. An oxygen concentrator according to claim 1. 3. The adsorbent particle holding member is positioned substantially perpendicular to the flow of air in the adsorbent bed and does not substantially cause flow resistance of the air in the adsorbent bed, The oxygen concentrator according to claim 1 or 2, wherein the filling portion is divided into 2 to 4 regions. 4. A part of the internal space of the surge tank means is filled with an adsorbent capable of adsorbing at least oxygen,
Inflow conduit means for the oxygen enriched gas from the adsorbent bed to enter the surge tank means is open in the adsorbent unfilled region of the surge tank means, and the oxygen enriched gas flows out of the surge tank means. Outflow conduit means open in the adsorbent fill region of the surge tank means, the outflow conduit means being connected to the product tank means via a check valve means, the product tank means containing the oxygen enriched gas. The oxygen concentrator according to any one of claims 1 to 3, wherein a supply means is connected. 5. The oxygen concentrator according to claim 1, wherein the step of reversely flowing the oxygen-enriched gas stored in the surge tank means to the adsorption bed is included in the pressure fluctuation adsorption step. 6. 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 such that the flow of gas within the adsorbent filling area is 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.