JPS58205523A - Supply device of oxygen enriched air - Google Patents

Abstract

PURPOSE:To economize charging energy for the entire part of a supply device for oxygen enriched air and to reduce the contamination of a filter by circulating part of oxygen lean air to a module accommodating chamber. CONSTITUTION:When a fan 4 is operated, the outside air passes through a filter 2 so as to be removed of dust and enters a module accommodating chamber 12. When an evacuation pump 3 is operated, the air in the chamber 12 is withdrawn through oxygen selective permeable membranes into modules 1 having said membranse on the surface. This air is discharged as oxygen enriched air through the discharge port 13 of the pump 3 past a header 8. On the other hand, the remaining oxygen lean air in the chamber 12 is discharged through a discharge port 6 by the fan 4, and part of the air is returned through a by-pass pipe 5 into the chamber 12. A control valve 7 for the flow rate of oxygen lean air and control valves 9-11 for the concn. and flow rate of the oxygen enriched air are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oxygen-enriched air supply device using an oxygen-selective permeable membrane module having an oxygen-selective permeable membrane on its surface.

Oxygen-enriched air is normal air (oxygen concentration 21vo1%)
It means air with a higher oxygen concentration ratio than that of air, and can be widely used for combustion air, treatment of people with respiratory disorders, sludge aeration treatment, and other industrial uses.

When this oxygen-enriched air is used for the above-mentioned purposes, the oxygen concentration may be relatively low, for example, about 23 to 30% for combustion, but it is desired that it be obtained at low cost. Such oxygen-enriched air can be easily obtained by diluting high-purity oxygen with normal air. When oxygen is used, there are many problems such as cost and safety that hinder its practical application. For this reason, in recent years, various attempts have been made to directly concentrate and separate oxygen from air using organic polymer membranes. This method uses a so-called oxygen-selective permeable membrane in which oxygen and nitrogen, which are the constituents of air, permeate more easily than nitrogen, and creates an appropriate pressure difference on both sides of the membrane. Then, air permeates through this membrane 1. At this time, oxygen permeates more easily than nitrogen, so the air that has passed through the membrane has a higher oxygen concentration than the original normal air! : h < becomes oxygen-enriched air. In a practical embodiment, the oxygen-selective permeable membrane is modularized into a certain shape, one membrane surface is exposed to air, the other membrane is kept airtight, and connected to, for example, a vacuum pump. When the vacuum pump is activated, air is drawn in from the membrane surface, enters the inside of the module, passes through the vacuum pump, and
Oxygen-enriched air is discharged from the discharge port of the vacuum pump. One specific configuration of such a system includes a module room that houses multiple modules, piping that collects permeate gas from each module, a vacuum pump connected to this piping, and a vacuum pump installed to adjust the flow rate. It is formed from valves. Others □ Various adjustment mechanisms will be added to this as necessary.

It is desirable to install a suitable filter in the air intake section of the module room to remove dust and other particles from the air, and also to install a blower (air intake) in order to create an air flow over the module surface. fresh air is introduced into the module room through a filter, and the remaining nitrogen-enriched air is removed by the module section. It is desirable to eliminate the With this configuration, sufficient oxygen-enriched air can be produced, but the amount of dust in the air is higher than expected, and the filter often requires cleaning. The amount of energy needed to blow air against the pressure loss is not small.

The present invention aims to improve these drawbacks by reducing the amount of filter cleaning required, reducing the energy consumption of the blower fan, and providing an oxygen-enriched air supply device using an oxygen-selective permeation method that achieves higher efficiency as a whole system. 1.

That is, the present invention uses an oxygen-selective permeable membrane module having an oxygen-selective permeable membrane on its surface, and uses this and a vacuum pump system to supply oxygen-enriched air. One end is open to the outside through a filter that removes dust, and the other end is used to exhaust oxygen-depleted air, and a portion of the oxygen-depleted air is returned to the module storage room. The oxygen-enriched air supply device is an oxygen-enriched air supply device □, and further, the rate of return of the oxygen-depleted air to the module storage chamber is 1, and the amount of oxygen-enriched air generated is
It is characterized in that it is the remaining Hayabusa that has been discharged out of the system at least six times as much.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an overall view of an oxygen enrichment supply device according to an embodiment of the present invention, in which 1 is a module having an oxygen-selective permeable membrane on its surface, and 2 is a filter.

4 is a blower; when the blower 4 is activated, the outside air passes through the filter 2, removes dust, and enters the module storage chamber 1.
Enter 2. When the vacuum pump 3 is operated, the air in the module storage chamber 12 is drawn into the module 1 through the oxygen-selective permeable membrane 1, and then passes through the ladder T8 to the discharge port 13 of the vacuum pump 3. 3 discharged as enriched air
) On the other hand, the remaining oxygen-depleted air in the module storage chamber 12 is discharged from the exhaust port 6 by the blower 4. At this time, a portion of this oxygen-depleted air is returned to the module storage chamber 12 via the bypass pipe 6. Reference numeral 7 denotes a control valve for controlling the amount of oxygen-depleted air to be returned. 9, 10° 11 are valves that adjust the oxygen concentration, flow rate, etc. of the generated oxygen-enriched air.

In such a configuration, the amount of air returning to the module storage chamber 12 via the bypass pipe 6 is changed by the valve 7, and the results of examining the oxygen concentration of the oxygen-enriched air obtained are
As shown in the figure. In this case, the achieved oxygen concentration differs depending on the total amount of air flowing into the module storage chamber 12 through the filter 2 and the amount of oxygen-enriched air discharged from the decompression pump 3.

The vertical axis in FIG. 2 indicates the oxygen concentration in oxygen-enriched air, and the horizontal axis indicates the amount of return air. Curve 21 in the figure shows the case where the flow rate ratio between the total inflow air amount and oxygen-enriched air is 10:1, and curve 22 shows the case where the flow rate ratio between the total inflow air amount and oxygen-enriched air is 20:1. In both cases, a polydimemethylsiloxane copolymer with a ratio of oxygen permeability coefficient to nitrogen permeability coefficient of approximately 2 is used as the membrane material, and the characteristics are obtained when the degree of vacuum is set such that the pressure ratio on both sides of the membrane is 6. It is. If there is no return from the bypass pipe 6, in the former case, that is, when the flow rate ratio is 10=1, the achieved oxygen concentration is 31.6 cm, and the return amount is about 26% of the total amount of oxygen-depleted air discharged. Up to this point, the oxygen concentration reached gradually decreases as the amount of return is increased, but it is sufficient for practical use as oxygen-enriched air. However, when the amount of feedback exceeds about 26 inches, the oxygen concentration in the module storage chamber 12 decreases significantly, and the oxygen concentration reached also decreases significantly. On the other hand, the latter
In other words, when the flow rate ratio is 20:1, the reached oxygen concentration is 32.5 when there is no return from the bypass pipe 6.
%, and when the oxygen-depleted air is returned through the bypass pipe 6, the oxygen concentration reached gradually decreases until the return amount reaches about 50%, but it is sufficient for practical use as oxygen-enriched air. However, if it exceeds about 60 inches, the oxygen content in the module storage chamber 12 will decrease significantly, and the oxygen concentration of the obtained oxygen-enriched air will also decrease, which is not preferable.

In this way, the amount of oxygen-depleted air that can be returned to the module storage chamber 12 varies depending on the ratio of the total amount of incoming air to the oxygen-enriched air obtained, and the larger this ratio is, the more oxygen-depleted air that can be returned. The amount can also be increased. Therefore, by changing the ratio between the total amount of air and the amount of oxygen-enriched air, and changing the amount of oxygen-depleted air discharged outside the system and the amount returned to the module storage room, the amount of oxygen-depleted air that is substantially generated is changed. As a result of measuring conditions under which the oxygen concentration in oxygen-enriched air is maintained above a certain level, the amount of oxygen-depleted air discharged outside the system is relative to the amount of oxygen-enriched air generated. It has been found that the remaining oxygen-depleted air can be returned to the module storage chamber by adjusting the amount to be at least 5 times or more, preferably 7.5 times or more.

When a part of the oxygen-depleted air is returned as described above, this air is already clean air from which dust has been removed by the filter 2, and the amount of fresh air flowing through the filter 2 is As a result, the energy consumption of the blower 4 for introducing air is reduced, and the contamination of the filter 2 is also reduced.

As described above, the present invention connects a vacuum pump system to an oxygen-selective permeable membrane having an oxygen-selective permeable membrane on its surface to obtain oxygen-enriched air that has passed through the oxygen-selective permeable membrane. In the oxygen-enriched air supply system, part of the oxygen-depleted air that was conventionally discharged outside the system is returned to the module storage room and reused. It is industrially very effective because it saves the overall input energy and reduces filter contamination.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an oxygen-enriched air supply device according to an example of the present invention, and Fig. 2 is a relationship between the oxygen-depleted air return amount and the achieved oxygen concentration of the oxygen-enriched air supply device according to the present invention. 1) 1...Module, 2.
...filter, 3.0...reducing pump, 4.
...Blower, 5...Life/bypass pipe, 6
...Discharge port, 7,9,10°11...
Control valve, 8... Header, 12... Module storage chamber.

Claims (2)

[Claims] (1) an oxygen-selective permeable membrane module having an oxygen-selective permeable membrane on its surface; and a module storage chamber that stores the oxygen-selective permeable membrane module and has an open end opened to the outside through a dust removal filter; A vacuum pump system connected to the oxygen-selective permeable membrane module, means for discharging oxygen-depleted air from the module storage chamber, and means for returning a portion of the exhausted oxygen-depleted air to the module storage chamber. 4. j. Oxygen-enriched air supply device. (2) The return needle for the oxygen-depleted air is a residual stitch from which at least six times the amount of oxygen-enriched air generated is discharged from the system. An oxygen-enriched air supply device according to claim 1.