JPS6336019Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an oxygen-enriched air supply device, and in particular, reduces the pressure on the downstream side of an oxygen selectively permeable membrane to enrich and supply oxygen concentration in the air flowing through the oxygen selectively permeable membrane. The present invention relates to an oxygen-enriched air supply device.

In conventional oxygen-enriched air supply devices, the downstream side of the oxygen selectively permeable membrane is sucked by a constant volume vacuum pump. However, the selective oxygen permeation membrane has the characteristic that as the differential pressure increases, as shown by curve 1 in FIG. 1, the air flow rate increases, and the obtained oxygen concentration increases, as shown by curve 2. Therefore, it is desirable that the vacuum pump be a pump that can obtain higher suction pressure. Also,
The permeability of the oxygen selectively permeable membrane is thought to deteriorate gradually over time, and with conventional vacuum pumps,
It is difficult to control the suction amount to an appropriate amount in response to the deterioration of the transmittance.

The present invention solves the above-mentioned technical problems, increases the suction pressure to obtain air with a higher concentration of oxygen, and also allows the air flow rate to be easily changed in response to changes in permeability. An object of the present invention is to provide an oxygen-enriched air supply device that can prevent deterioration of oxygen enrichment efficiency.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a system diagram of an embodiment of the present invention.
A conduit 9 including a first regeneration pump 6, a cooler 7, and a second regeneration pump 8 in this order is connected to the downstream side of the oxygen selectively permeable membrane 5. Oxygen selective permeable membrane 5
The first regeneration pump 6 creates a negative pressure of, for example, about -8000 mmAq on the downstream side of the membrane, and the pressure difference between the pressure on the upstream side of the oxygen selective permeable membrane 5 and the approximately atmospheric pressure causes the air to become oxygen selective. It passes through the permeable membrane 5 and is enriched with oxygen. The temperature of the oxygen-enriched air increases due to the heat of compression from the first regeneration pump 6.
For example, minus 5000mmAq
It is sucked into the second regeneration pump 8 with a certain pressure. The second regeneration pump 8 supplies the oxygen-enriched air after being pressurized to approximately atmospheric pressure.

FIG. 3 is a simplified cross-sectional view of the first regeneration pump 6. The casing 11 of the regeneration pump 6 includes a substantially cylindrical main body portion 12 and side covers 13 and 14 that are fixed by closing both ends of the main body portion 12.
including. A partition wall 15 that is orthogonal to the axis is fixedly provided at a central position within the main body portion 12 along the axis. In this way, a space is formed in the casing 11, which includes the main body portion 12 and both side covers 13 and 14, to rotatably accommodate the pair of impellers 16 and 17.

The outer peripheral edges of the side covers 13 and 14 are configured to bulge in opposite directions, and these bulges 18 and 19 form ventilation passages 20 and 21 over almost the entire circumference. . A groove 2 facing each ventilation passage 20, 21 is provided at the outer peripheral edge of both impellers 16, 17.
3 and 24 are formed to be separated from each other, and each groove 23 and 24 is divided into a plurality of grooves along the circumferential direction by a plurality of partition plates 25 and 26 located in a plane including the axis of the drive shaft 22. has been done. In addition, each groove 23, 24
The edge of each partition plate 25, 26 is connected to the reinforcing member 2.
7, 28 may be connected to each other.
Providing these reinforcing members 27 and 28 not only improves the strength of each partition plate 25 and 26, but also allows the air to form a vortex smoothly as shown by the arrow, and the air Efficiency is improved because there is no turbulence in the flow.

Rotation bearings 29 and 30 are provided at the center of the partition wall 15 and the side cover 14, respectively.
A single drive shaft 22 on which both impellers 16 and 17 are fixedly provided passes through the partition wall 15 and the side cover 14 via the two rotation bearings 29 and 30. Furthermore, inside the casing 11, the side cover 1
A rotation and thrust bearing 31 is provided at the center of the drive shaft 2.
2 ends are received. Further, a pulley 32 as a rotating member is detachably fixed to the drive shaft 22 protruding from the side cover 14. This pulley 3
An endless belt 33 serving as a transmission member is wound around 2. Further, the belt 33 is wound around a pulley 36 fixed to an output shaft 35 of a motor 34. Therefore, by driving the motor 34, the drive shaft 22 is rotationally driven.

FIG. 4 is a left side view of FIG. 3. The side cover 13 has a suction port 37 at a position adjacent to the circumferential direction.
and a discharge port 38 are formed, and these suction port 37 and discharge port 38 are communicated with both ends of the ventilation path 20. Note that the ventilation passage 20 is formed to have a central angle from the suction port 37 to the discharge port 38 along the direction shown by the arrow 39. The other side cover 14 is also formed with a suction port 40 and a discharge port 41 in the same manner as described above, and the discharge port 3
8 and the suction port 40 are formed at substantially the same position along the circumferential direction. The discharge port 38 of one side cover 13 is connected to the suction port 40 of the other side cover 14 via a communication pipe 42, so that both ventilation passages 20, 21 are in communication with each other. Note that the suction ports 37, 40 and the discharge ports 38, 41 may be formed on the end surfaces of both side covers 13, 14 as shown in FIG. may be formed.
Furthermore, the discharge port 38 and the suction port 40 are omitted, and a single hole is bored in the partition wall 15, so that both the ventilation channels 20, 21
may be communicated.

The second regeneration pump 8 is the first regeneration pump 6 described above.
It has exactly the same configuration as .

According to such regeneration pumps 6 and 8, after the air is pressurized in one ventilation path 20, it is further pressurized in the other ventilation path 21, so that a higher suction pressure can be obtained. becomes possible. Therefore, the differential pressure across the selectively permeable oxygen membrane 5 can be increased to increase the oxygen enrichment concentration.

Moreover, in each regeneration pump 6, 8, the ventilation passage 2
Since the air passages 20 and 21 are formed on sides separated from each other, the heat generated by compressing the air in each of the ventilation passages 20 and 21 is efficiently radiated from the surface of the casing 12.

By the way, the permeability of the oxygen selectively permeable membrane 5 decreases due to dirt on the surface of the membrane due to long-term use, resulting in the same state where the effective passage area of the oxygen selectively permeable membrane 5 decreases. Therefore, the situation is the same as increasing the air flow rate per effective unit passage area by increasing the suction pressure. However, as shown in FIG. 5, when the suction pressure increases, the power consumption of the regeneration pumps 6 and 8 increases. Therefore, in order to avoid an increase in power consumption, it is necessary to maintain the air flow rate per unit effective area approximately equal to prevent the suction pressure from increasing.

Here, the characteristics of the regeneration pumps 6 and 8 are shown in FIG. In FIG. 6, the curve A shown by a solid line is a characteristic curve when the number of revolutions is relatively high, and the curve shown by a broken line is a characteristic curve when the number of revolutions is relatively low. In addition, in FIG. 6, the characteristic curve C of the oxygen selectively permeable membrane 5 is shown by a two-dot chain line.
As is clear from FIG. 6, when the rotational speed of the regeneration pumps 6 and 8 is reduced, the amount of suction air decreases for the same suction pressure. Therefore, in the regeneration pumps 6 and 8, the diameter of the pulley 32 is changed to reduce the rotation speed, thereby reducing the overall air suction amount while keeping the suction pressure almost constant, and reducing the air flow rate per effective unit passing area. is brought into almost the same state as before the oxygen selectively permeable membrane 5 deteriorates. This makes it possible to maintain the oxygen enrichment concentration at the same level as before the deterioration. Moreover, since the suction pressure does not increase, the power consumption of the regeneration pumps 6 and 8 does not increase.

Since the pulley 32 is detachably fixed to the drive shaft 22, adjustment of the rotational speed of the regeneration pumps 6, 8 can be achieved extremely easily.

In other embodiments of the present invention, the second regeneration pump 8 may be omitted. Also, a belt 33 and pulleys 32, 36 are connected between the drive shaft 22 and the motor 34.
Instead of the connection, the connection may be made by a transmission means consisting of an endless chain and a sprocket wheel, in which case the sprocket wheel may be detachably fixed to the drive shaft 22.

As mentioned above, according to the present invention, a regeneration pump is used in which air is suctioned by passing through a pair of air passages sequentially using a pair of impellers fixed to a single drive shaft, so the suction pressure can be compared. The target size can be increased, thus improving suction efficiency. Moreover, the rotation speed of the regeneration pump can be changed extremely easily.
The oxygen enrichment concentration can be maintained at a substantially constant level by changing the amount of suction air according to the change over time of the oxygen selectively permeable membrane.

[Brief explanation of the drawing]

Figure 1 shows the characteristics of the oxygen selective permeable membrane, Figure 2
The figure is a system diagram of an embodiment of the present invention, Figure 3 is a simplified sectional view of the first regeneration pump 6, Figure 4 is a left side view of Figure 3, and Figure 5 is a diagram showing the suction pressure and pressure of the regeneration pump. A graph showing the relationship between power consumption and FIG. 6 is a graph showing the characteristics of the regeneration pump. 5... Oxygen selective permeation membrane, 6... First regeneration pump, 8... Second regeneration pump, 16, 17... Impeller, 20, 21... Ventilation path, 22... Drive shaft, 2
3, 24...Groove, 32...Pulley, 33...Belt, 34...Motor.

Claims (1)

[Claims for Utility Model Registration] In an oxygen-enriched air supply device that reduces pressure on the downstream side of an oxygen selectively permeable membrane and supplies oxygen-enriched air passing through the oxygen selectively permeable membrane, A pair of mutually communicating ventilation passages are provided on the downstream side of the permeable membrane, and a pair of impellers having a plurality of grooves facing each ventilation passage around the entire circumference are fixed to a single drive shaft, A regeneration pump that sequentially passes through the ventilation path and suctions air is connected, a rotating member is detachably fixed to the drive shaft, and an endless transmission member that transmits the driving force of the motor is wound around the rotating member. An oxygen enriched air supply device characterized in that it can be hung.