JPH03186313A - Oxygen enrichment device - Google Patents

Abstract

PURPOSE:To make it possible to process a large amount of air by superposing oxygen-nitrogen separation membranes having an oxygen permeation coefficient of specific value or more and parallelly disposed wires alternately on one another to form them into a body. CONSTITUTION:The air delivered from a fan 4 is passed through a filter 5 to be cleaned thereby and sent through a piping 6 into layers Y of an oxygen enrichment device 1. The air in layers X of the device 1 is drawn by means of pressure reducing pump 7 and passed through oxygen-nitrogen separation membranes, whereby the oxygen enriched air is taken out through a piping 8 from the pump 7. For the oxygen-nitrogen membranes, poly[1-(trimethylsilyl)-1- propyne], organopolysiloxane, natural rubber, etc., are employed. Oxygen permeation coefficient of these membranes is 1X10<-10>cm<3>.cm/cm<2>.sec.cmHg or more. As a result, low cost is achieved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention applies to gasoline, kerosene, light oil, 9 heavy oil, LNG (liquefied natural gas), and LPG (liquefied petroleum gas).

Oxygen-enriched air is used in internal combustion engines such as automobiles and aircraft that mix fuel such as city gas with air and burn it as a combustible gas mixture, as well as in combustion devices such as cement kilns, boilers, and household gas ranges. Devices for producing oxygen-enriched air to increase combustion efficiency, or oxygen supply sources useful for oxygen inhalation therapy performed on hypoxemic patients with chronic bronchitis, emphysema, sequelae of pulmonary tuberculosis, etc. Relating to a device for producing enriched air.

[Prior Art] Conventionally, as a method for producing such oxygen-enriched air, a method using an organic polymer thin film is known. This method is
This is an attempt to generate oxygen-enriched air by concentrating the oxygen in the air by utilizing the difference in gas permeability that passes through organic polymer thin films, increasing the oxygen concentration in the atmosphere (21%) by 30 to 40%.
If it can be used in a combustion device, it will be possible to reduce fuel consumption and save energy, and it can also be used as an oxygen supply source for medical purposes.

The conventional oxygen production method, cryogenic air separation, compresses and
After cooling, fractional distillation is performed using the difference in boiling points.
Compared to consuming huge amounts of electrical energy, the production of oxygen-enriched air using an oxygen-enriched membrane requires only 1 at.
This method is attracting attention as an inexpensive method because of its simple mechanism, in which air with a high concentration of oxygen is sent through the membrane, and the pressure on the other side of the membrane is reduced to about 0.1 stm, thereby generating air with a high oxygen concentration.

Oxygen enrichment membranes that have been announced so far include dimethylpolysiloxane-polycarbonate block copolymer membrane (GE Corp., USA) and polyhydroxystyrene-dimethylpolysiloxane-polycarbonate block copolymer membrane (Kenko Denki Sangyo). and so on.

However, conventional membranes of this type have a small amount of gas permeation, and are only applicable to small oxygen inhalers for medical use. The fuel weight ratio, that is, the air-fuel ratio is approximately 15, and the fuel consumption is 10 km/β and 40 km/hr.
Assuming that the vehicle is traveling at a constant speed, the amount of air required for this combustion is:
40/l0X15=60℃/hr. ) is only at the research stage.

[Problems to be solved by the invention] The properties of polymer membranes are generally determined by the oxygen/nitrogen separation coefficient (hereinafter referred to as P
. , / p , , marked. Although it is easy to form a thin film with a polymer film with a large ), the gas permeability coefficient is small, and a polymer film with a large gas permeability coefficient is difficult to form a thin film with P. */PHm tends to be small. That is, the oxygen permeability coefficient (hereinafter referred to as P ox) is the maximum value among conventionally known polymers (3,52X 10-"Cm"°
cra/cta"-sea-cmHg (hereinafter, the unit is omitted) is PG
! /P□ is as low as 1.94, and thin film formability is 20-30μ
m is the limit and P. ! Polyvinyl acetate, which has the highest I/Pl value (7,03) among polymer films, has a P 02 of 2.25X10- even though it is possible to form a film with a thickness of 1 μm or less.
”, which is three orders of magnitude smaller. Therefore, from the viewpoint of thin film formation, the current practice is to make compromises by sacrificing the gas permeability coefficient, such as by copolymerizing organopolysiloxane with other resins. be.

The present inventors used organopolysiloxane as a base resin and filled it with various powder materials to produce Po
1 liter is increased several times to several tens of times that of organopolysiloxane,
They were conducting research to supplement thin film deposition performance, but in the process they realized that there were limits to developing film materials alone, and that they needed to develop an oxygen-enriching device.

The present inventors have discovered that an oxygen-enriched membrane made of a polymer membrane material is P. t
, P, , /P□, and found that there is a limit in terms of balancing the thin film formation performance, and found that the limit can be overcome by creating a device using these films.

Therefore, it is an object of the present invention to provide an oxygen enrichment device capable of processing large volumes of air.

[Means for Solving the Problems] In order to achieve the above object, the oxygen enrichment device of the present invention includes an oxygen/nitrogen separation membrane having an oxygen permeability coefficient of 1×1o-10 or more and parallel array wires. , the separation membranes are formed by alternately stacking and integrating, and the adjacent separation membranes are separated from each other,
and the wires are formed so that the arrangement direction is substantially orthogonal between the upper and lower layers, and the separation membrane is made of organopolysiloxane filled with high silica zeolite. be.

The oxygen enrichment device of the present invention will be explained based on the accompanying drawings.

FIG. 1 is a schematic perspective view of an example of the oxygen enrichment device of the present invention, and FIG. 2 is a schematic diagram showing an oxygen enrichment system using the oxygen enrichment device of the present invention.

FIG. 1 depicts a device 1 consisting of seven oxygen/nitrogen separation membranes with three layers each for the air supply layer and the oxygen-enriched air suction layer.

The oxygen/nitrogen separation membranes 2 are laminated in the Z-axis direction, and parallel array wires 3 are sandwiched and integrated between the oxygen/nitrogen separation membranes 2, and these parallel array wires are alternately stacked in the X-axis direction for each layer. and are arranged in the Y-axis direction. These wire layers need to be orthogonal to each other, but this is strictly geometrically 9
It doesn't have to be 0 degrees, it just needs to be substantially orthogonal,
A range of 80 degrees to 100 degrees is preferable.

These wire layers are arranged in order from the bottom: X1 layer, IYI layer, X layer, Y layer.
If we have layer layer, X8 layer, and ys layer, 1 atm of air becomes Y
It is sent from the axial direction to the Y layer, and the X layer is
When suctioned in the axial direction, the oxygen-enriched air that has passed through the oxygen/nitrogen separation membrane is taken out from the X3 layer, X2 layer + Xs layer. In this way, the permeation flow rate increases in proportion to the number of calendars,
A large amount of oxygen-enriched air can be obtained.

In FIG. 1, sealing of the end surface opposite to the oxygen-enriched air outflow surface in the X-axis direction is not illustrated, but it is natural that the end surface is sealed for use. Furthermore, since both sides are open in the Y-axis direction, air can flow in through the membrane and unnecessary nitrogen-enriched air can be exhausted at the same time.

Such oxygen-enriched air can be effectively produced using, for example, an oxygen enrichment system shown in FIG.

That is, the air sent by the ventilation fan 4 is purified by passing through the filtration filter 5, and is sent into the Y layer of the oxygen enrichment device 1 of the present invention through the piping system 6. Further, the X layer of the device 1 is sucked by a vacuum pump 7 and passes through an oxygen/nitrogen separation membrane, and the oxygen-enriched air is passed through a piping system 8.
Nitrogen-enriched air which is removed from the vacuum pump through the membrane and which does not pass through the separation membrane is exhausted from the Y-layer of the device, usually on the opposite side of the piping system 6.

As the oxygen/nitrogen separation membrane according to the present invention, poly[1-(
trimethylsilyl)-1-propyne] (Pog=7.7
3X 10-'Pot/PHx=1.55; Hereinafter, P o- and P ox/ P- will be omitted and the numerical values will be written in parentheses in this order. ), organopolysiloxane (3
, 52X10-”, 1.94), natural rubber (2,34X
10-”, 2.46), polybutadiene (1,9X10
-”, 2.95), ethylcellulose (1,47X10
-', 3.32), ethylene-vinyl acetate copolymer (8
, OX 10-”2.76), low density polyethylene (2
, 89X10-”, 2.98), polystyrene (2,0
1X 10-” 6.38), polycarbonate (1
, 4X10-” 4.67), butyl rubber (1,3X
10-”, 4.0), etc. Among these, organopolysiloxane has a low p O-/p nt, but
It is most preferable to use organopolysiloxane because it is extremely superior as an oxygen/nitrogen separation membrane in that its o2 is one to two orders of magnitude higher.

Regarding dimethylpolysiloxane, which is the basic system of organopolysiloxane, the present inventors measured P using a gas permeability measuring device. When z+Pox/Psi was actually measured, they were (3 to 7)xlO-'' and 1.8 to 2.1, respectively.

P from organopolysiloxane. 8 is one digit higher than poly [1
-(trimethylsilyl)-1-propyne] is Pox
However, if this problem is solved, it will become a promising oxygen/nitrogen separation membrane according to the present invention.

The thinner the gas permeable membrane is, the higher the permeation flow rate, but as mentioned above, dimethylpolysiloxane has poor thin film forming properties on its own, and the maximum thickness is 20 to 30 μm. It is preferable to use it by forming a thin film. This porous support membrane includes polypropylene,
Examples include porous films made of polysulfone, polyimide, aromatic polyester, and the like.

In addition, according to the research of the present inventors, a thin film made by blending and filling this dimethylpolysiloxane with high silica zeolite,
Several times to several tens of times more P than dimethylpolysiloxane film. The use of this thin film is more preferable since it is possible to obtain 3.

The composition formula of zeolite is, for example, naturally occurring mordenite is NaO''Ag* Os'l OS i 016H*O
1 go or zeolite type A is Nag 0-AQz Os・2
SiOi 4.5H* 0 is a porous crystal body in which SiO4 tetrahedrons and (A I!, 04)-tetrahedrons are combined in a three-dimensional network, and has countless pores with a diameter of approximately 1 nm. in,
Because it exhibits unique adsorption performance, it is used in dehydrating agents, desiccants, molecular sieves, adsorbents, catalysts, ion exchange agents, etc. High silica zeolide is also called ZSM-5 type zeolite and is S i Ox /A12m Os
The ratio shows large values ranging from 15 or more to infinity. Among these, Silicalite 8 [Stow] manufactured by UCC in the United States is famous as a zeolite with infinite S i Ot /AQx Os. ] There is. The pore structure of this silicalite crystal has a diameter of 0.57×0.51n.
m elliptical 10-membered ring straight channel of oxygen atoms and a diameter of 0
．． It has a structure in which a zigzag channel of a 54 nm approximately circular 10-membered oxygen atom ring is combined, and the present inventors believe that when dimethylpolysiloxane is filled with 60% by weight or more of this, P. It has been experimentally confirmed that 2 can be increased several times to several tens of times.

That is, P using a gas permeability measuring device. 2 is based on actual measurements, dimethylpolysiloxane single film is 4.0X1
0-" Dimethylpolysiloxane membrane filled with 60% silicalite is 15X10-'~20XIO-" Dimethylpolysiloxane membrane filled with 80% silicalite is 4
0.times.10-s, 90% by weight silicalite filled dimethylpolysiloxane membrane can obtain values as high as 135.times.10-'.

P of these membranes. */ p,, actual value is 1.8 to 2
It was in the range of 1°.

The above-mentioned high-silica zeolite-filled dimethylpolysiloxane membrane has poor thin film forming properties of dimethylsiloxane. However, according to the research of the present inventors, the above-mentioned poly[1-( )-limethylsilyl)-1-propyne], it was found that thin film formability could be improved and a POI several times higher than that of dimethylpolysiloxane alone could be obtained. According to the film-forming experiments conducted by the present inventors, when these are blended at a ratio of 50:50, it is possible to form a film of approximately 2 to 3 μm.
P at this time. 2 Actual value is 20~30)xlO-',
P,,/P,, the actual value was 1.8.

Examples of the method for forming the oxygen/nitrogen separation membrane according to the present invention include a solution casting method, a T-die method, an extrusion method, an inflation method, a calender roll method, an l-axis or biaxial stretching method, and the like.

Further, examples of the method for forming a film on the support film include gravure roll coating, Meyer bar coating, doctor knife coating, reverse roll coating, air knife coating, microgravure coating, and the like.

The thinner the oxygen/nitrogen separation membrane is, the better it is to the extent that it does not cause pinholes when processing a large amount of air. However, if it is not a composite membrane with a porous support membrane, handling From the viewpoint of ease of use, it is desirable that the thickness be 1 μm or more. When forming a composite membrane with a porous support membrane, it is preferable to use a membrane with a submicron thickness within a range that does not cause pinholes. The upper limit of the film thickness is 1100 μm, preferably about 30 μm in terms of air throughput.

Examples of the array wire according to the present invention include metal wires made of stainless steel, nickel, copper, nickel silver, brass, phosphor bronze, etc., or polymer linear bodies such as polyester, polyamide, aromatic polyamide, etc. For manufacturing reasons, it is more preferable to use a metal wire that has excellent strength and does not expand or contract.

If the diameter of the array wire is too small, the spacing between the separation membranes will become narrow and air will not be able to flow in. If it is too thick, the spacing between the separation membranes will become large and the stacking density of the separation membranes will decrease, resulting in oxygen-enriched air. The diameter φ is usually disadvantageous because the amount of φ produced is small.
Those with a diameter of 10 um to φ3 mm are used. Preferably φ
It is in the range of 50 μm to φ1 mm.

The arrangement pitch of the parallel arrangement lines is usually 0.5 to 50, because if it is too small, it will impede the inflow of air, and if it is too large, it will prevent the separation between adjacent separation membranes and impede the inflow of air.
A range of 111 is used. In particular, a range of 1 to 2 mm is desirable.

The method of adhering the array wire and the separation membrane is to laminate the uncured separation membrane to the brimer-treated array wire and then bond them together using a die press, or to apply an adhesive to the cured separation membrane. There is a method of laminating the coated array wires and then bonding them together using a die press, but the latter method is more practical considering the handling of thin films and the handling of thin films coated on porous supports.

[Function] According to the oxygen enrichment device configured as described above, the injected air passes through a large number of oxygen/nitrogen separation membranes stacked in multiple stages via array wires, and is enriched with a large amount of oxygen. The nitrogen-enriched air, which is efficiently extracted as air and does not pass through the separation membrane, is easily discharged.

[Example] Liquid dimethylpolysiloxane with a viscosity of 60 Pa-s,
KE1935A/B (manufactured by Shin-Etsu Chemical, trade name) 4
0% by weight, high silica zeolite, silicalite”
(Manufactured by UCC, trade name) 60% by weight and dissolved in toluene/kerosene mixed solvent, viscosity 50Pa-s
As a solution, Teflon" TFE (E, 1
．． Coated on a separator (product name manufactured by Dupont), evaporated the solvent at 100°C for 10 seconds, and crosslinked at 180°C for 30 minutes to a thickness of 25 μm.
- A membrane body was obtained.

When this high-silica zeolite-filled dimethylpolysiloxane membrane was peeled off from the separator and measured using a pressurized gas permeability measuring device, Gas Balm'-100 (manufactured by JASCO Corporation, trade name), the Pot was 20X10- ”
is about 5 times that of dimethylpolysiloxane, and P os/
P Ml was 2.0, which corresponds to dimethylpolysiloxane.

, φ which was treated with silane-based brimer using the device's ゛PPM wiring equipment (manufactured by Shin-Etsu Polymer ■, transparent touch panel manufacturing equipment)
0.2mm 5US-304 wire, wiring pitch 1
．． 0mm, and two-component RTV silicone rubber, TSE-3360 (manufactured by Toshiba Silicone ■,
The high silica zeolite-filled dimethylpolysiloxane film described above was laminated in multiple layers so that the wiring directions were substantially perpendicular to each other for each upper and lower layer, and then placed in a press mold and integrated by press molding. .

Next, this end face is polished to a vertical (X-axis direction)
mm x horizontal (Y-axis direction) 300 mm x height (Z-axis direction) 3
A laminated block with a thickness of 0.00 mm was formed, and the surface opposite to the enriched air outflow direction in the X-axis direction was sealed with silicone epoxy resin.

Using the device manufactured in this way, we manufactured and tested the oxygen enrichment system shown in Figure 2 above. It was possible to obtain oxygen-enriched air with a measured oxygen concentration of approximately 35% by a flow rate of 100 Q/hr.

[Effects of the Invention] According to the oxygen enrichment device of the present invention, conventionally known oxygen/nitrogen separation membranes such as dimethylpolysiloxane membranes and copolymer membranes of dimethylpolysiloxane and other resins, as well as high By using an oxygen/nitrogen separation membrane such as a silica zeolite-filled dimethylpolysiloxane membrane, combining it with parallel wires, and simply stacking it in multiple layers, you can create an inexpensive oxygen enrichment device that can separate and process a large amount of air at once. can be provided. Furthermore, because of its structure, it can be miniaturized, so it can be used not only for producing small amounts of oxygen-enriched air for medical purposes, but also for combustion by being mounted on an automobile.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the oxygen enrichment device of the present invention. FIG. 2 is a schematic diagram showing an oxygen enrichment system using the oxygen enrichment device of the present invention. 1...Oxygen enrichment device 2...Oxygen/nitrogen separation membrane 3...Parallel array wire 4...Blower fan 5...Filtration filter 6.8...Piping system 7...Reducing pressure bomb

Claims (1)

[Claims] 1. Oxygen permeability coefficient is 1×10^-^1^0cm^3・c
It is made by laminating and integrating oxygen/nitrogen separation membranes of m/cm^2・sec・cmHg or more and parallel array wires,
An oxygen enrichment device characterized in that the adjacent separation membranes are formed so as to be spaced apart from each other and the arrangement directions of the wires are substantially orthogonal between the upper and lower layers. 2. The oxygen enrichment device according to claim 1, wherein the oxygen/nitrogen separation membrane is made of organopolysiloxane filled with high silica zeolite.