JP2001239124A - Oxygen concentrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxygen concentrator adjusting a supply flow rate of oxygen gas corresponding to a user's state to supply the oxygen gas in a stable flow rate and enabling not only the miniaturization of an adsorbing column and a buffer tank but also the facilitation of the assembling work and maintenance of both of them. SOLUTION: A pressure regulator 41, an automatic flow rate control valve 42, a flow rate adjusting resistor 45 and a control part 50 are provided between the buffer tank 31 and an oxygen taking-out port 12. Inlets and outlets are respectively provided to the upper parts of two adsorbing columns and the intermediate parts of these columns are bent to be formed into an almost U- shape and the buffer tank is arranged between these adsorbing columns to be integrated with the adsorbing columns.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an oxygen concentrator for obtaining concentrated oxygen from air by a compression swing adsorption system.

[0002]

2. Description of the Related Art A conventional oxygen concentrator is known which comprises a plurality of adsorption towers filled with an adsorbent and separates nitrogen and oxygen from air to obtain concentrated oxygen by a compression swing adsorption system. ing. In this type of oxygen concentrator, air compressed by a compressor is sent to one of the adsorption towers via a control valve, and the adsorbent in the adsorption tower adsorbs nitrogen in the compressed air to form concentrated oxygen. Generated and
The nitrogen in the other adsorption tower after the completion of the adsorption step is released to the outside via the control valve. By switching the control valve, the concentrated oxygen generated in each adsorption tower is sequentially taken out and stored in the buffer tank. Oxygen gas is supplied from the buffer tank to the outside through an oxygen outlet.

FIG. 11 shows a structure of an adsorption tower and a buffer tank. Inlets 1a and 2a are provided on the upper surfaces of at least two adsorption towers 1 and 2 formed in a cylindrical shape, respectively.
Compressed air is supplied to two adsorption towers 1 via a control valve (not shown),
Air is alternately sent to 2. Concentrated oxygen obtained by adsorbing nitrogen on the adsorbent in the adsorption towers 1 and 2 passes through check valves 3 and 4 from outlets 1 b and 2 b provided on the lower surface of the adsorption towers 1 and 2 to form a buffer tank. 5 and supplied to the outside through an oxygen outlet (not shown).

A variable throttle valve and a plurality of orifices are provided between the buffer tank and the oxygen outlet so as to be switchable. With this arrangement, the oxygen gas supply supplied from the oxygen outlet to the outside is provided. The flow rate can be adjusted mechanically.

[0005]

However, the conventional oxygen concentrator has the following problems. (1) The oxygen gas supply flow rate is determined by the amount of compressed air generated from the compressor to the adsorption tower and the amount of adsorbent charged in the adsorption tower.
A machine is used which is set to an optimal oxygen gas supply flow rate according to the state of the above. Therefore, when the state of the user changes and the supply flow rate of oxygen gas is changed, it is necessary to replace the oxygen gas supply flow with another machine set to the supply flow rate. (2) If an orifice is provided between the buffer tank and the oxygen outlet, the oxygen gas supply flow rate will not be stable due to variations in the orifice hole diameter and internal pressure, and the actual oxygen gas supply flow rate will differ from the set value. There is. Further, since the actual oxygen gas supply flow rate is not measured, even if the supply flow rate fluctuates significantly for some reason, it is not known. (3) Since at least two adsorption towers and a buffer tank for storing oxygen gas are separately arranged and connected by piping, the number of parts is large, and the space occupied by the adsorption tower and the buffer tank is large. It is getting bigger.
Further, since each pipe is long and complicated, the assembling work is complicated and maintenance is not easy. The present invention solves such a conventional problem, and can adjust the oxygen gas supply flow rate according to the state of the user.
Eliminates variations in the supply flow rate of oxygen gas, can supply oxygen gas at a stable flow rate over a long period of time, and further improves the structure of the adsorption tower and buffer tank to reduce its size, assembling work and maintenance. It is intended to provide an excellent oxygen concentrator that can easily carry out the above.

[0006]

In order to achieve the above object, an oxygen concentrator according to the present invention has an automatic flow control valve disposed between a buffer tank and an oxygen outlet. At the subsequent stage, there is provided a flow rate adjusting resistor composed of a plastic sintered body filter or a columnar fiber bundle filter. In this way, the supply flow rate of oxygen gas can be adjusted according to the state of the user, and the supply flow rate of oxygen gas can be made uniform, and oxygen gas can be supplied at a stable flow rate. The oxygen concentrator of the present invention is also provided at the outlet of the buffer tank and regulates the pressure to a constant value, an automatic flow control valve disposed between the pressure regulator and the oxygen outlet, and a subsequent stage. The flow rate of the oxygen gas passing through the automatic flow rate control valve by detecting the pressure between the flow rate adjustment resistor disposed therein and the automatic flow rate control valve and the flow rate adjustment resistor, and setting a predetermined supply A control unit for controlling the automatic flow control valve to the flow rate.
In this way, the oxygen gas supply flow rate can be adjusted according to the state of the user, and the oxygen gas can be supplied at a stable flow rate over a long period of time. The oxygen concentrator of the present invention also includes a plurality of adsorption towers filled with an adsorbent, the adsorption towers are provided with inlets and outlets respectively above, and formed in a substantially U-shape with an intermediate portion folded back. A buffer tank is arranged between the adsorption towers, and the adsorption tower and the buffer tank are integrated. Further, a check valve is provided by opening a passage in the outlet of the adsorption tower and the partition wall of the buffer tank. In this way, the structure of the adsorption tower and the buffer tank can be improved, the size of the product can be reduced, and the assembling work and maintenance can be easily performed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an oxygen concentrator according to an embodiment of the present invention will be described in detail with reference to the drawings. 1 and 2 show the appearance of the oxygen concentrator. FIG.
As shown in FIG. 1A, an oxygen outlet 12 for supplying oxygen gas to the outside and a display panel 13 for displaying the supply flow rate of oxygen gas are provided at the front of the oxygen concentrator 11, and a one-touch coupler is provided below the display panel 13. A humidifying bottle 15 is detachably attached via. As shown in FIG.
An air intake port 16 is opened in the back of the oxygen concentrator 11, and a handle 17 is mounted on the upper portion thereof. Further, a main power switch 18 is provided at a lower portion of the rear surface. FIG.
As shown in (a), a “+” button B ₁ for setting an oxygen gas supply flow rate is provided at a front part of the upper surface of the oxygen concentrator 11.
An operation panel 19 provided with a “−” button B ₂ and a start button B ₃ is provided. As shown in FIG. 2B, a power cable 20 is provided at a lower portion of the rear surface, and a caster 21 for movement is provided at a lower surface.

FIGS. 3 and 4 show the configuration of the device inside the oxygen concentrator 11, and the block diagram of FIG. 5 shows the entire configuration of the oxygen concentrator. In FIG. 5, the air taken in from the intake port 16 is compressed by the compressor 25. The drive power supply frequency of the compressor 25 (hereinafter simply referred to as “frequency”) is controlled by an inverter device 26. In order to maintain the predetermined oxygen gas concentration and supply flow rate, the control unit 50 controls the inverter device 26, and the frequency is moved up and down to adjust the rotation speed of the compressor 25.

The compressor 25 is provided with a blower 22 for cooling the pump, as shown in FIGS. This blower 22 allows a large amount of air to be supplied to the oxygen concentrator 11.
The pump is cooled by being taken in. The air that has cooled the pump is discharged from the air outlet 23 to the outside. The inlet (not shown) of the blower 22 or the oxygen concentrator 11
By providing an air purifying device 24 such as an air dust collector or a negative ion generator in the exhaust port 23 of the above, the air in the room where the oxygen concentrator 11 is installed can be purified.

In FIG. 5, compressed air from a compressor 25 is sent to one adsorption tower 29 or the other adsorption tower 30 via a control valve 28. These adsorption towers 29, 30
Adsorbent 32 such as natural zeolite or synthetic zeolite
Is filled, and nitrogen in the compressed air is adsorbed by the adsorbent 32 by the compression swing adsorption method, whereby nitrogen and oxygen are separated to generate concentrated oxygen. This adsorption tower 29 or 3
The concentrated oxygen taken out after passing through the buffer tank 3
Stored in 1.

As shown in FIG. 6A, the two adsorption towers 29 and 30 are formed of a synthetic resin in a cylindrical shape,
a, 30a and outlets 29b, 30b are respectively provided on the upper side, and the intermediate portions 29c, 30c are formed in a folded U-shape. Each of the adsorption towers 29 and 30 is divided into upper and lower parts in order to reduce the size of a resin molding die. In this way, the adsorption towers 29 and 30 respectively
A letter-shaped passage is formed. These adsorption towers 29, 3
A buffer tank 31 is arranged between the zero. Adsorption tower 2
Passages are opened in the outlets 29b, 30b of 9 and 30 and the partition wall of the buffer tank 31, and check valves 65 and 66 are provided so that the concentrated oxygen stored in the buffer tank 31 does not flow back to the adsorption towers 29 and 30. It has a structure. Thus, the adsorption towers 29 and 30 and the buffer tank 31 have an integral structure.

The adsorption towers 29 and 30 are assembled as follows. After the adsorption towers 29 and 30 are filled with the adsorbent 32 such as the above-mentioned natural zeolite, as shown in FIG. 6 (b), the adsorption towers 29 and 30 and the buffer tank assembled in an integrated structure having a square shape in a plan view. 31 on top
7 is attached, and pipes 68a, 68a are piped on the inlet 29a, 30a side of the adsorption tower and connected to the control valve 28. At the same time, a pipe 68b is provided on the outlet 31b side of the buffer tank 31, and this pipe is used for
Connected to.

FIG. 7 shows a modification of the adsorption towers 29 and 30. The adsorption towers 29 and 30 are formed in a rectangular tube shape in a plan view, and the entrance 29 is formed by partition walls 291c and 301c.
a, 30a and outlets 29b, 30b.
The lower ends of the partition walls 291c and 301c are attached to the adsorption towers 29 and 30, respectively.
Is formed shorter than the entire length in the height direction. The buffer tank 31 is formed in a substantially square shape. The lower surfaces 29d and 30d of the adsorption tower and the lower surface 31d of the buffer tank are open, respectively, so that resin molding is easy even if they are not vertically divided. In this way, the buffer tank 31 is disposed between the outlet 29b side of the one adsorption tower 29 and the outlet 30b side of the other adsorption tower 30, and the adsorption towers 29, 30 and the buffer tank 31 are integrated. . As described above, the passages are opened in the outlets 29b and 30b of the adsorption tower and the partition wall of the buffer tank 31, and the check valves 65 and 66 are provided in the passages.

The open lower surfaces 29d, 3d of the respective adsorption towers
0d, a rectangular lower lid 6 on the lower surface 31d of the buffer tank
9 is fixed and the lower surfaces 29d, 30d, and 31d are closed, and a U-shaped passage is formed in the adsorption towers 29 and 30.
After the adsorbent 32 is filled in the adsorption towers 29 and 30, FIG.
As shown in (b), an upper lid 70 is attached to the upper surfaces of the adsorption towers 29 and 30 and the buffer tank 31 having a rectangular structure in a plan view, and a pipe 6 is provided at the entrances 29a and 30a of the adsorption tower.
8a and 68a are connected to the control valve 28, and the pipe 68a is connected to the outlet 31b side of the buffer tank 31.
b is connected to a flow control device 40 described later.

By forming the passages in the adsorption towers 29 and 30 in a U-shape in this manner, the adsorption towers 29 and 30 are formed.
The internal volume required for the suction operation can be secured without increasing the overall length of the device. In addition, both adsorption towers 29, 3
0, the buffer tank 31 is disposed, and the adsorption tower 29,
30 and the buffer tank 31 have an integrated structure,
The number of parts can be reduced, and the space occupied by the adsorption towers 29 and 30 and the buffer tank 31 can be reduced. Moreover, while shortening the piping of each pipe 68a, 68b, the outlet 29b of the adsorption tower 29,30,
Since the check valves 65 and 66 are provided by opening the passages in the partition wall of the buffer tank 31 and the partition 30b, the piping structure can be simplified and the assembling work can be facilitated.

In FIG. 5, the compressed air from the compressor 25 is sent to one of the adsorption towers (for example, the adsorption tower 29), and as the adsorption of nitrogen proceeds, the pressure in the adsorption tower 29 increases. Go. When the air sent to the adsorption tower 29 rises to a predetermined pressure, the detection signal of the pressure sensor 33
The control unit 50 determines that the adsorption process of one adsorption tower 29 has been completed. In this case, the control valve 28 is switched so that the compressed air from the compressor 25 is
And nitrogen is adsorbed by the adsorbent 32 in the other adsorption tower 30 to generate concentrated oxygen. At the same time, one of the adsorption towers 29 after the completion of the adsorption step is opened, and nitrogen is discharged to the atmosphere.

Thus, by switching the control valve 28,
The process of adsorbing nitrogen in one adsorption tower 29, opening the other adsorption tower 30 and discharging nitrogen to the outside is sequentially and alternately repeated. In this way, the plurality of adsorption towers 29 and 30 are alternately used, and the concentrated oxygen is continuously generated. Note that, if the moisture in the compressed air sent to the adsorption towers 29 and 30 is high, the nitrogen adsorption efficiency is reduced. Therefore, as shown in FIG.
And an alumina tower 34 is provided between the
By 4, the moisture in the compressed air sent to the adsorption towers 29 and 30 is removed. The removed water is stored in the drain 35.

In FIG. 5, the concentrated oxygen stored in the buffer tank 31 is led out to the oxygen outlet 12,
On the way, a concentration sensor 36 and a flow rate adjusting device 40 are provided to detect whether or not the oxygen gas has a predetermined concentration (90%) and to adjust the supply flow rate of the oxygen gas. The flow control device 40 is provided between the buffer tank 31 and the oxygen outlet 12 as shown in FIG. The flow regulator 40 includes a pressure regulator 41 and an orifice 44 in series from the outlet of the buffer tank 31 in series.
And an automatic flow control valve 42 and a resistor 45. Here, the automatic flow control valve 42 includes a stepping motor 46
The opening area is changed by the drive of, and the passing flow rate is adjusted. A pressure sensor 43 is provided between the automatic flow control valve 42 and the resistor 45, and detects the pressure between the two.

In this manner, the pressure of the oxygen gas extracted from the buffer tank 31 to the orifice 44 is adjusted to a constant level by the pressure regulator 41, and the flow rate of the oxygen gas passing through the orifice 44 is adjusted by the automatic flow control valve 42. Adjusted.

Further, since the resistor 45 is provided at the subsequent stage of the automatic flow control valve 42, the pressure between the automatic flow control valve 42 and the resistor 45 changes according to the opening area of the automatic flow control valve 42. I do. A resistor 45 made of a plastic sintered filter such as a polyethylene shown in FIG. 9A in addition to a normal orifice (not shown) is used as the resistor 45.
a, a resistor 45b made of a columnar fiber bundle filter such as the cigarette filter shown in FIG.

An experiment was conducted using a resistor 45a made of a plastic sintered filter, a porous body having a diameter D of about 7 mm and a length L of about 9 mm, and having a pore H having a diameter of 10 μm. When a conventional orifice is provided at the subsequent stage of the automatic flow control valve 42, as shown by a dotted line in FIG. 10, when the supply flow rate is low at "0" to "3.0", the pressure changes slowly, The resolution when calculating the flow rate from the change in pressure is low, and a flow rate adjustment error is likely to occur. On the other hand, when the resistor 45a made of a plastic sintered body filter is provided, the change in pressure is substantially proportional to the change in supply flow rate, as indicated by the chain line in FIG. In the case where the resistor 45b made of a columnar fiber bundle filter such as a cigarette filter is also provided, the change in pressure and the change in supply flow rate are substantially proportional as shown by the solid line in FIG.

Therefore, if the pressure between the automatic flow control valve 42 and the resistor 45 is detected by the pressure sensor 43 and the corresponding data of the pressure and the flow rate are obtained in advance by an experiment, the pressure detected by the pressure sensor 43 is obtained. Thus, the flow rate of the automatic flow control valve 42 can be accurately calculated. Also, since the actual oxygen gas supply flow rate is measured from the pressure conversion value, the control unit 50
Then, the stepping motor 46 is driven based on the detection value of the pressure sensor 43, and the supply flow rate of the automatic flow control valve 42 can be automatically adjusted so that the supply flow rate is set in advance on the operation panel 19.

The user's operation is performed by the operation panel 19, and the oxygen gas supply flow rate can be arbitrarily changed within a predetermined range according to the state required by the user.
In the present embodiment, the oxygen concentrator 11 has an oxygen gas concentration of 90%.
%, And the maximum supply flow rate is 5 L / min. By operating the “+” button B ₁ or the “−” button B ₂ , “0”, “0.25”, “0.5” “ 0.75 "
“1.0” “1.5” “2.0” “2.5” “3.0”
“3.5” “4.0” “4.5” “5.0” (L / mi
The supply flow rate of 13 steps of n) can be set. The oxygen gas supply flow rate set on the operation panel is digitally displayed on the display panel 13.

Based on this setting, the control unit 50 controls the inverter device 26 to automatically adjust the rotation speed of the compressor 25, and also automatically controls the flow rate control device 40 to obtain the optimum oxygen gas concentration and supply flow rate. Is maintained. A humidifying bottle 15 is located immediately before the oxygen outlet 12.
Is provided in a removable manner. By filling the humidifying bottle 15 with purified water, oxygen gas from which moisture is removed and dried passes through the purified water in the humidifying bottle 15. Oxygen gas can contain moderate humidity.
Therefore, oxygen gas having a predetermined concentration and appropriate humidity can be stably supplied from the oxygen outlet 12 to the outside at a set supply flow rate.

The present invention can be variously modified without departing from the spirit of the present invention, and it is natural that the present invention extends to the modified ones.

[0026]

According to the present invention, as is apparent from the above embodiment, an automatic flow control valve is disposed between a buffer tank and an oxygen outlet, and a plastic sintered filter or a columnar fiber bundle is provided at a subsequent stage. Since a flow control resistor consisting of a filter is provided, the pressure change between the automatic flow control valve and the flow control resistor and the change in the oxygen gas supply flow rate passing through the automatic flow control valve have a substantially proportional relationship. By detecting the pressure, the supply flow rate of oxygen gas can be calculated, and in particular, a pressure change at a low flow rate can be accurately detected. Therefore, the supply flow rate of the oxygen gas can be adjusted according to the state required by the user, and the oxygen gas can be supplied at a stable flow rate without variation in the supply flow rate. The present invention is also provided with a pressure regulator provided at the outlet of the buffer tank to regulate the pressure to a constant value, an automatic flow control valve disposed between the pressure regulator and the oxygen outlet, and a subsequent stage. Detecting the pressure between the resistor and the automatic flow control valve and the resistor to calculate the flow rate of oxygen gas passing through the automatic flow control valve,
A control unit that controls the automatic flow control valve to a preset supply flow rate is provided, so that the control unit automatically controls the opening area of the automatic flow control valve to set according to the state required by the user. The supplied oxygen gas supply flow rate can be supplied. In addition, it is very easy to change the supply flow rate of oxygen gas, and it is not necessary to replace it with another oxygen concentrator each time, and oxygen gas can be supplied at a stable flow rate for a long time. The present invention also comprises a plurality of adsorption towers filled with an adsorbent, these adsorption towers are provided with an inlet and an outlet above, respectively, and the intermediate part thereof is formed in a substantially U-shape by folding, and these adsorption towers are formed. Since the buffer tank is provided between the two and the adsorption tower and the buffer tank are integrated, the space occupied by the adsorption tower and the buffer tank can be reduced and the piping can be simplified. Therefore, the size of the oxygen concentrator can be reduced, and
Assembly work is simplified, and maintenance can be facilitated.

[Brief description of the drawings]

FIG. 1A is a front view showing an appearance of an oxygen concentrator according to an embodiment of the present invention. FIG. 1B is a rear view showing an appearance of the oxygen concentrator.

FIG. 2A is a plan view showing an appearance of the oxygen concentrator. FIG. 2B is a side view showing an appearance of the oxygen concentrator.

FIG. 3A is a front view showing the internal structure of the oxygen concentrator. FIG. 3B is a rear view showing the internal structure of the oxygen concentrator.

FIG. 4 is a side view showing the internal structure of the oxygen concentrator.

FIG. 5 is a block diagram showing the overall configuration of the oxygen concentrator.

FIG. 6 (a) is a perspective view showing a structure before piping of an adsorption tower and a buffer tank provided in the oxygen concentrator. (B) is a perspective view showing a structure of the adsorption tower and buffer tank provided in the oxygen concentrator after piping.

FIG. 7A is a perspective view showing a structure before piping of an adsorption tower and a buffer tank provided in the oxygen concentrator (a modified example). FIG. 7B is a structure after piping of an adsorption tower and a buffer tank provided in the oxygen concentrator. Perspective view showing (change example)

FIG. 8 is a block diagram of a flow control device provided in the oxygen concentrator.

9A is a perspective view of a resistor made of a plastic sintered body filter used in the oxygen concentrator, and FIG. 9B is a perspective view of a resistor made of a columnar fiber bundle filter used in the oxygen concentrator.

FIG. 10 is a graph showing a relationship between a pressure and a flow rate of oxygen gas by a flow rate adjusting device used in the oxygen concentrator.

FIG. 11 is a perspective view showing the structure of an adsorber and a buffer tank used in a conventional oxygen concentrator.

[Description of Signs] 11 Oxygen concentrator 12 Oxygen take-out port 13 Display panel 14 One-touch coupler 15 Humidifier bottle 16 Intake port 17 Handle 18 Main power switch 19 Operation panel 20 Power cable 21 Caster 22 Blower 23 Exhaust port 24 Air purifier 25 Compressor Reference Signs List 26 Inverter 28 Control valve 29 Adsorption tower 29a Inlet 29b Outlet 29c Intermediate part 291c Partition wall 30 Adsorption tower 30a Inlet 30b Exit 30c Intermediate part 301c Partition wall 31 Buffer tank 32 Adsorbent 40 Flow control device 41 Pressure regulator 42 Automatic flow control valve 43 Pressure Sensor 44 Orifice 45 Resistor 45a Resistor made of plastic sintered body 45b Resistor made of columnar fiber bundle filter 46 Stepping motor 50 Control unit 65 Check valve 66 Check valve 67 Lid 68a pipes 68b pipes 69 beneath lid 70 lid

Claims (6)

[Claims] 1. An oxygen concentrator that generates concentrated oxygen by adsorbing nitrogen in compressed air to an adsorbent by a compression swing adsorption method, stores the concentrated oxygen in a buffer tank, and supplies oxygen gas from an oxygen outlet to the outside. An oxygen concentrator, wherein an automatic flow control valve is disposed between a buffer tank and an oxygen outlet, and a flow regulating resistor is provided at a stage subsequent to the automatic flow control valve. 2. The oxygen concentrator according to claim 1, wherein the flow rate adjusting resistor is formed by a plastic sintered body filter. 3. The oxygen concentrator according to claim 1, wherein the flow rate adjusting resistor is formed by a columnar fiber bundle filter. 4. A pressure regulator provided at an outlet of the buffer tank to regulate the pressure to a constant level, an automatic flow control valve disposed between the pressure regulator and the oxygen outlet, and a pressure regulator disposed at a subsequent stage. Detecting the pressure between the flow control resistor and the automatic flow control valve and the resistor to calculate the flow rate of the oxygen gas passing through the automatic flow control valve, and setting the automatic flow control valve to a preset supply flow rate The oxygen concentrator according to any one of claims 1 to 3, further comprising a control unit for controlling. 5. A method comprising a plurality of adsorption towers filled with an adsorbent,
An inlet and an outlet are provided above each of these adsorption towers,
5. The method according to claim 1, wherein an intermediate portion thereof is formed in a substantially U-shape by folding back, a buffer tank is disposed between the adsorption towers, and the adsorption tower and the buffer tank are integrally formed. Oxygen concentrator. 6. The oxygen concentrator according to claim 1, wherein a passage is opened in an outlet of the adsorption tower and a partition wall of the buffer tank to provide a check valve.