JP2011092905A - Method for manufacturing degassing membrane, envelope-like object, and degassing device using the envelope-like object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a degassing membrane easily manufacturable with an easily stabilizable form of a liquid flow path, and a degassing device manufactured by the method. <P>SOLUTION: The degassing membrane is manufactured by forming a protrusion part to a first air permeating membrane by discharging hot melt resin on the first air permeating membrane, hardening the resin of the protrusion part, and forming a second air permeating membrane on the first air permeating membrane to cover the protrusion part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a deaeration membrane for degassing a gas dissolved in a liquid, an envelope-like product produced by the method, and a deaeration apparatus using the envelope-like material.

  In various fields such as chemical product manufacturing, food manufacturing, medical care, electrical equipment, and semiconductor manufacturing equipment, it is often necessary to degas (gas-liquid separation) the gas dissolved in the liquid. When the liquid contains a solid suspension such as functional particles, a conventional hollow fiber type deaeration module is easily clogged because the diameter of the hollow fiber opening is small.

  As another deaeration device, a device in which a porous polymer film material that allows dissolved gas to permeate is stacked in a roll shape (spiral shape) or a pleat shape to form a module is known. In this type of apparatus, degassing is performed by configuring a removal gas channel in which one side of the membrane material is a liquid channel and the other side of the membrane material is decompressed (Patent Documents 1 to 4).

  For example, in FIGS. 8 to 11 of Patent Document 1, an envelope-like membrane structure made of a synthetic resin thin film and having a closed periphery in a casing forms a liquid channel through which liquid to be deaerated is passed. A deaeration device is described that is stacked in a spiral or pleat shape through a liquid flow path forming material. Further, as shown in FIG. 10 of Patent Document 1 (FIG. 13 of the drawings attached to the present specification), this membrane structure (envelope-like deaeration membrane) 51 forms a flow path for the removal gas therein. A liquid flow path forming material 53 is formed outside the membrane structure 51 by a liquid flow path forming material 53, and the liquid flow path forming material 53 is located inside the membrane structure 51. When the pressure is reduced, the liquid flow path is formed by closely contacting the thin film constituting the membrane structure 1.

JP-A-10-76106 (FIGS. 8 to 11) JP-A-8-332306 (FIGS. 5-7) JP-A-9-225206 (FIGS. 7 to 10) JP-A-10-216403 (FIGS. 8 to 11)

  However, in the conventional degassing apparatus described in Patent Document 1, functional particles are gradually deposited at the intersection of the screen net used as a spacer for the liquid flow path, and the pressure loss increases, which is the worst case. Causes blockage due to clogging.

  In addition, as shown in FIG. 13 of the present specification, when a rib-like (tubular) three-dimensional structure is formed in advance using a liquid channel forming material, the manufacturing process of the membrane structure itself is complicated. Further, as far as judging from FIG. 13, since the liquid flow path forming material is composed of a thread-like material (or a fibrous material), it is considered that (1) it is not easy to form it into a rib shape, (2) It is considered that it is very easily deformed by external stress. Since the film is easily deformed, the rib shape reflected on the surface of the thin film is not always constant due to the degree of decompression and the uneven pressure in the film structure, and the liquid flow becomes unstable. An object of this invention is to provide the manufacturing method of the deaeration membrane which is easy to manufacture and the shape of a liquid flow path is easy to stabilize, and the deaeration apparatus manufactured by this method.

  The method for producing a degassing membrane of the present invention that has achieved the above object comprises a step of forming a protrusion on the first gas permeable membrane by discharging a resin onto the first gas permeable membrane, and a resin for the protruding portion. And a step of forming a second gas permeable film on the first gas permeable film so as to cover the protrusion.

  In the above manufacturing method, it is desirable to use a hot melt resin as the resin of the protruding portion.

  In the above manufacturing method, it is desirable to form the protruding portion in a rib shape.

  In the above manufacturing method, it is desirable to meander the rib-shaped protrusion.

  In the manufacturing method, it is desirable to form the protrusions in a dot shape.

  The envelope-like object of the present invention that has achieved the above object includes covering the gas flow path forming material by covering one side surface of the sheet-shaped gas flow path forming material with the degassing film and the other side surface with a gas permeable film. To do.

  In the envelope-shaped article, it is desirable to use the degassing membrane instead of the gas permeable membrane used on the other side surface.

  In the envelope-shaped object, it is desirable to form a protrusion formed on one side of the gas flow path forming material and a protrusion formed on the other side at the same position on the front and back of the gas flow path forming material. .

  In the envelope-shaped object, it is desirable to form a protrusion formed on one side of the gas flow path forming material and a protrusion formed on the other side at different positions on the front and back of the gas flow path forming material. .

  The deaeration device of the present invention that can achieve the above-mentioned object is one in which the deaeration membrane produced by the above production method is stored in a spiral or pleated form in a casing having a liquid inlet and a liquid outlet. is there.

  In the deaeration device, it is desirable that the ribs of the protrusions are formed at an angle of 5 to 85 degrees with respect to the liquid flow direction in the housing.

  With the method for producing a degassing membrane of the present invention and the degassing device produced by the method, it is possible to provide a method for producing a degassing membrane that is easy to produce and has a stable liquid channel shape. Become. Moreover, the deaeration apparatus manufactured by this method can be provided.

It is a partial perspective view of the envelope-shaped thing in embodiment of this invention. It is a figure which shows the spiral laminated body of the said envelope-shaped thing. It is a figure which shows the pleated laminated body of the said envelope-shaped thing. It is a figure which shows the deaeration apparatus in embodiment of this invention. It is a figure which shows the manufacturing process of the deaeration membrane in embodiment of this invention. The modification of the protrusion part in embodiment of this invention is shown. The modification of the protrusion part in embodiment of this invention is shown. The modification of the protrusion part in embodiment of this invention is shown. The modification of the protrusion part in embodiment of this invention is shown. The modification of the protrusion part in embodiment of this invention is shown. An example of the envelope-shaped object in embodiment of this invention is shown. The other envelope-shaped object in embodiment of this invention is shown. It is a perspective view of the conventional deaeration membrane.

  Hereinafter, a manufacturing method of a deaeration membrane concerning an embodiment of the invention is explained in detail based on a drawing.

  FIG. 1 is a partial perspective view of an envelope 1 having a deaeration membrane according to an embodiment of the present invention. As shown in FIG. 1, an envelope 1 is composed of PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer) films 5 and 10, and a gas flow path formed of nylon, polyester, or the like is formed therein. A knit material 2 as a material, a porous PTFE (polytetrafluoroethylene) film 3 formed on one side of the knit material 2, and a porous PTFE film as a first ventilation film formed on the other side of the knit material 2 4. A rib 6 formed as a protrusion on the porous PTFE membrane 4 is provided. The PFA film 5 as the second gas permeable film has a convex portion 5 a reflecting the three-dimensional shape of the rib 6 in order to cover the rib 6.

  In the present specification, a laminated structure including at least the porous PTFE film 4 that is the first gas permeable film, the rib 6, and the PFA film 5 that is the second gas permeable film is described as a deaeration film. Further, a structure in which an envelope is formed by the PFA film 5 and the PFA film 10 and the porous PTFE films 3 and 4 laminated on both sides of the knit material 2 are inserted into the envelope is referred to as an envelope 1. ing.

  The gas in the liquid to be deaerated is deaerated by the following method. In FIG. 1, the outside of the envelope 1 is a flow path of the degassed liquid, and the degassed liquid flows in the direction of arrow A. On the other hand, the inside of the envelope 1 is in a reduced pressure state. Thereby, the gas dissolved in the liquid moves to the knit material 2 side through the permeable PFA film 5 and the porous PTFE film 4. This gas is then exhausted in the direction of arrow B.

  As described above, in the description of the envelope 1, the knit material 2 and the porous PTFE membrane 3 are used as the gas flow path forming material, but these are not essential constituent requirements of the deaeration membrane manufactured in the present invention. The deaeration membrane itself may be anything as long as it includes at least a laminated structure including the first gas permeable membrane (porous PTFE membrane 4), the protruding portion (rib 6), and the second gas permeable membrane (PFA membrane 5).

  As described above, the gas flow path forming material is preferably formed, but it is not always necessary to use a knit material, and a material capable of moving gas inside may be used. For example, a cloth made of nylon cloth, urethane sponge, polyester, polypropylene net, metal net, etc. can be used, and the form of the cloth is a gas flow path forming material such as woven fabric, knitted fabric, sponge, non-woven fabric, net, etc. can do. The thickness of the gas flow path forming material is desirably 0.1 to 5 mm (preferably 0.3 to 2 mm).

  In the above description, the case where the porous PTFE membrane 4 excellent in waterproofness is used as the first gas permeable membrane has been described. However, not only PTFE but also liquid can be prevented and gas can permeate. Any polyethylene, polypropylene, polystyrene, polyimide, etc. can be used. The first gas permeable membrane preferably has low wettability with respect to the hot melt resin used in the present invention. This is because the hot melt resin has a role of forming protrusions on the first gas permeable membrane.

  When a porous PTFE membrane is used as the first gas permeable membrane, the porosity of the porous PTFE membrane is preferably 20 to 90% (preferably 50 to 80%). The thickness is desirably 5 to 100 μm (preferably 10 to 50 μm).

  In the above description, the case where the PFA membrane 5 is used as the second gas permeable membrane has been described. However, any material can be used as long as it can prevent liquid permeation and allow gas to permeate. Tetrafluoroethylene / hexafluoropropylene Various resins such as copolymers, polyethylene, and polypropylene can be appropriately used alone or as a mixture of two or more. These materials can prevent the permeation of liquid and impart a function of gas permeation (liquid prevention / breathability), and also have high chemical resistance (organic solvent, acid, alkali) and high heat resistance.

  The envelope-like object 1 used in the present invention is preferably attached with an exhaust member (not shown) for evacuation at an appropriate position such as a terminal part or a central part so that the inside thereof is decompressed. As the exhaust member, a tube-shaped member made of an appropriate material can be used. An example of a preferred material is PFA. When PFA is used as an exhaust member, there is an advantage that it is made of the same material as the PFA film 5 and is easily heat-sealed. The outer diameter of the exhaust member is preferably about 4 to 10 mm, and the wall thickness is preferably about 0.5 to 1 mm.

  Another example of a preferable method of attaching the exhaust member is a method of making a hole in the fold of the envelope-like object 1 and attaching it to the envelope-like object 1 through a pipe-like shaft in this hole. For attachment, the envelope-shaped object 1 and the shaft are sandwiched by using a ring-shaped part provided inside the envelope-shaped object 1 and an O-ring provided inside the shaft.

  In the present invention, about 5 to 100 layers of the envelope-like material 1 are stacked to form a laminated body, and this laminated body is housed in a casing made of synthetic resin or metal to constitute a deaeration device. As a form of the laminated body, for example, the envelope-like object 1 may be laminated in a spiral shape as shown in FIG. 2, or may be laminated in a pleated shape as shown in FIG. In any form, since there is a protrusion due to the presence of the rib 6 on the surface of the envelope-like object 1, this protrusion serves as a spacer to form a gap between the envelope-like objects 1 and this is degassed. It becomes a flow path for flowing a liquid.

  FIG. 4 shows a configuration example of a deaeration device in which the above laminate is housed in a housing. In FIG. 4, for example, the pleated laminate shown in FIG. 3 is accommodated in the housing 12 (the accommodated laminate may of course be the spiral laminate shown in FIG. 2). One end of the exhaust member 15 is attached to an appropriate position of the envelope-like object 1, and the other end of the exhaust member 15 is drawn out of the housing 12. The casing 12 is provided with a liquid inlet 13 for the liquid to be degassed, a liquid outlet 14 for the liquid to be degassed, and an air hole 16 for releasing air at the start of degassing. Further, a synthetic resin net 17 is disposed in the casing 12 to prevent the envelope 1 from blocking the liquid inlet 13, the liquid outlet 14 of the liquid to be deaerated, the air holes 16, and the like. Yes. In such a configuration, when the liquid to be degassed is supplied from the liquid inlet 13 and the envelope-like object 1 is decompressed by a vacuum line (not shown) connected to the other end of the exhaust member 15, the liquid channel The gas dissolved in the liquid to be deaerated passed through the PFA film 5 and the porous PTFE film 4 of the envelope 1 is degassed, and the removed gas is the knit material 2. The gas is exhausted from the exhaust member 15 to the outside of the housing 12 through the formed gas flow path.

  However, the housing structure used in the present invention is not limited to those exemplified here, and other known structures can be adopted.

  In addition, the first degassing apparatus according to the present invention includes not only degassing of gas dissolved in ordinary water, aqueous solution, solvent liquid, etc., but also high concentration solvent liquid, oil liquid, liquid containing surfactant, semiconductor Degassing can be performed efficiently even for special liquids used in manufacturing. The gas dissolved in the liquid may be various gases that show a gaseous state at normal temperature and pressure, such as oxygen, carbon dioxide gas, nitrogen gas, and hydrocarbon gas.

  In the method for producing a degassing membrane of the present invention, first, ribs 6 are formed on the porous PTFE membrane 4 by discharging hot melt resin onto the porous PTFE membrane 4 which is the first gas permeable membrane. FIG. 5 is a diagram showing a hot-melt resin discharge process. As shown in FIG. 5, while the hot melt applicator 18 capable of discharging a fixed amount of molten hot melt resin is translated in the direction of arrow C, the softened hot melt resin is discharged on the porous PTFE film 4 in a line shape. As a result, the rib 6 is formed. Since the hot melt applicator 18 shown in FIG. 5 has four discharge nozzles, four ribs 6 can be simultaneously formed in parallel.

  Next, after the rib 6 is solidified, a PFA film 5 as a second gas permeable film is formed on the porous PTFE film 4 so as to cover the rib 6 (see FIG. 1). The PFA film 5 may be adhered to the porous PTFE film 4, but the PFA film 5 adheres to the porous PTFE film 4 when the knit material 2 side is decompressed without being fixed. When the PFA film 5 is bonded to the porous PTFE film 4, the bonding method may be heat fusion or an adhesive, but the air permeability and flexibility are not impaired. Therefore, the thing by heat fusion is preferable.

  The porous PTFE film 4 may be laminated with the knit material 2 and the porous PTFE film 3. The porous PTFE film 3 and the knitted material 2, and the knitted material 2 and the porous PTFE film 4 can be bonded to each other by heat fusion. Of course, you may make it adhere | attach using an adhesive agent.

  As for the shape of the rib 6 which is a protrusion part of this invention, it is still more desirable to satisfy the following conditions. For example, the width of the rib 6 is 0.1 to 3 mm, preferably 0.2 to 1 mm, and more preferably 0.3 to 0.7 mm. The height of the rib 6 is 0.2 to 2 mm, preferably 0.3 to 0.7 mm. The pitch of the ribs 6 (distance between adjacent ribs 6) is 1 to 20 mm, preferably 3 to 10 mm.

  As described above, the case where the hot melt resin is used as the material constituting the rib 6 has been described. However, in the present invention, not only the hot melt resin but also a resin that is cured by cooling from a liquid state or a chemical reaction (photoreaction is performed). A resin that is cured by being included) can be used.

  Specific examples of resins that are cured from a liquid state include (1) epoxy resins, urethane resins, silicone resins, acrylic resins, etc. as reaction-curable resins, and (2) acrylic resins, cyanoacrylate resins as photocurable resins. (3) Solvent-soluble resins such as silicone resins and epoxy resins include natural rubber, styrene butadiene rubber, nitrile rubber, ABS, PVA, and nitrocellulose.

  As the hot melt resin constituting the rib 6, it is desirable to use a modified olefin resin, a urethane resin, a polyamide resin or a copolymer resin thereof. In addition, polyester resins, butyral resins, polyvinyl acetate resins or copolymer resins thereof, cellulose derivative resins, polymethyl methacrylate resins, polyvinyl ether resins, polycarbonate resins, polyvinyl chloride resins, etc. Various resins can be appropriately used alone or as a mixture of two or more.

  In the above description, the case where the linear rib 6 is formed to provide the protrusion on the porous PTFE film 4 has been described. However, the shape of the protrusion is not particularly limited, and various shapes are appropriately adopted. It is also possible.

  6-10 shows the modification of a protrusion part. However, in order to represent the shape of the protruding portion, the second gas-permeable membrane (PFA membrane 5 in FIG. 1) is omitted in each case. FIG. 6 shows a discontinuous portion formed in the rib 6 which is a protruding portion. Since the rib 6 has a shape that is interrupted in the middle, the liquid to be degassed can go back and forth between the ribs 6. Therefore, the pressure loss of the liquid channel can be reduced.

FIG. 7 shows the protrusions in the form of dots. Since there are few things blocking the flow of the liquid to be degassed, the pressure loss is further reduced. However, when the dot density is too low, the role of the spacer between the envelope-like object 1 and the envelope-like object 1 cannot be fulfilled sufficiently, and the pressure loss may increase. In order to keep the pressure loss low, the dot density is desirably 0.1 to 10 / cm ² (preferably 1 to 5 / cm ² ).

  FIG. 8 shows a case where the ribs 6 having the interrupted portions shown in FIG. 6 are used, and the interrupted portions are alternately arranged in every other row. With such an arrangement, it can be expected that the deaeration effect is promoted by stirring the liquid to be deaerated and causing turbulent flow.

  FIG. 9 uses a straight rib 6, but the rib 6 is in a flow direction of the liquid to be deaerated in the housing 12 (arrow A (FIG. 4) parallel to the housing 12). It is formed at an angle of 5 to 85 degrees (preferably 30 to 60 degrees, more preferably 30 to 45 degrees). The direction forming the angle may be either the left or right direction with respect to the direction of the arrow A. By providing the ribs 6 obliquely in this way, the path of the liquid to be deaerated increases, so that more sufficient deaeration can be performed.

  FIG. 10 shows a case where the rib 6 has a meandering shape. Even when the ribs 6 meander, the path of the liquid to be degassed increases, so that more sufficient deaeration can be performed. The meandering shape may be a curved meandering as shown in FIG. 10, or may be a linear meandering with continuous broken lines.

  FIG. 11 shows an envelope 1 that encloses the knit material 2 by forming the above-described degassing film on both the front and back sides of the knit material 2 that is a gas flow path forming material. That is, the difference from the envelope-shaped object 1 shown in FIGS. 6 to 10 is that the ribs 6 according to the present invention are arranged on both side surfaces of the gas flow path forming material. In the envelope-shaped object 1 of FIGS. 6-10, since the length of the 2nd ventilation film (PFA film | membrane 5 and PFA film | membrane 10 (refer FIG. 1)) in the front and back of the knit material 2 differs, an envelope for deaeration When the pressure inside the shaped object 1 is reduced, the envelope-shaped object 1 does not cause a desired deformation and may cause a considerably complicated deformation. Therefore, in order to make the lengths of the PFA film 5 and the PFA film 10 equal on the front and back sides of the knit material 2, it is more desirable that the ribs 6 are arranged on both the front and back sides of the knit material 2 as shown in FIG. 11.

  The position where the back side rib 6 is arranged may be the true back side position corresponding to the front side rib 6 as shown in FIG. 11, that is, the same position on the front side and back side, or as shown in FIG. The positions may be different from each other (for example, alternate positions (positions shifted by a half wavelength)).

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.

  Since the protruding portion of the degassing membrane of the present invention is formed by discharging hot melt resin, it is clear that it is easier to manufacture than the conventional degassing membrane shown in FIG. Since it is clear that the shape of the flow path is stable, an experiment for directly comparing the conventional degassing membrane shown in FIG. 13 with the degassing membrane of the present invention was not conducted.

(Example)
1. Preparation of test sample A three-layer laminate material was prepared by laminating a porous PTFE membrane having a width of 32 cm and a length of 10 m, a knit material, and another porous PTFE membrane by thermal fusion. On this three-layer laminate, ribs of hot melt resin were formed with a width of 1.5 mm, a height of 0.5 mm, and a pitch of 6 mm. The longitudinal direction of the rib was parallel to the direction (short direction) perpendicular to the longitudinal direction of the three-layer laminate material. The method for forming the rib is as follows.

  Using a hot melt applicator (hot melt multiple bead system) manufactured by Nordson Corporation having a multi-head nozzle (H200 mini bead nozzle (6 holes for one nozzle)), modified olefin type hot melt resin (Sekisui Fuller) Manufactured, trade name: Esdyne 8515DA-1) were arranged with a width of 1.5 mm, a height of 0.5 mm, and a pitch of 6 mm. The hot melt resin discharge conditions by the hot melt applicator are as follows.

Heater temperature:
(Tank and hose: 165 ° C)
(Gun part: 170 ° C)
Liquid pressure of liquid resin (heating and melting cylinder):
100 psi (= 0.69 Mpa)
Calibration: 0.13g per 30cm bead
Nozzle distance (distance from nozzle tip to porous PTFE membrane 4): about 2 mm

  The three-layer laminate material on which the ribs were formed was inserted into an envelope formed of a PFA film having a thickness of 25 μm, a hollow shaft for vacuuming was attached to one end of the envelope, and both ends were sealed by heat sealing. When the inside of the PFA envelope was evacuated through the hollow shaft, the PFA film was thin and flexible, so that it closely adhered along the rib and was rolled up around the shaft to form a spiral laminate. This laminate was housed in a stainless steel case 12, led from the center of the flange through the hollow shaft and led out of the case to produce a deaeration device (a deaeration module).

2. Degassing test Pure water was circulated through the degassing module as a liquid to be degassed under two flow conditions, and the dissolved oxygen concentration and pressure loss at the liquid outlet were measured. However, the temperature of pure water at the liquid inlet was 25 ° C., and the concentration of dissolved oxygen saturated at atmospheric pressure was 8.1 mg / liter.

(Comparative example)
Basically, a roll laminate was formed using an envelope-like material in which a three-layer laminate material was sealed in a PFA envelope as in the example. The difference from the examples is that no ribs are formed on the three-layer laminate in the comparative example, and in the comparative example, a PFA mesh (60 mesh, thickness 0.5 mm) is placed outside the envelope. The cylindrical deaeration module was formed by placing and winding up the inside of the PFA envelope while evacuating through the hollow shaft.

  Similarly, in the comparative example, pure water was passed through the degassing module under two kinds of flow conditions, and the dissolved oxygen concentration and the pressure loss at the liquid outlet were measured. The results are shown in Table 2 below. Various conditions of pure water at the liquid inlet are the same as in the example.

  As can be seen from Tables 1 and 2, in the degassing device of the comparative example, there was a large pressure loss between the liquid inlet and the liquid outlet (Tests 3 and 4), but in the degassing device of the example, The pressure loss was well below the target value of 1 kPa and was below the measurement limit. In both Examples and Comparative Examples, it can be seen that if the flow rate is reduced, the dissolved oxygen concentration at the liquid outlet becomes lower and the deaeration function is further enhanced.

DESCRIPTION OF SYMBOLS 1 Envelope 2 Knit material 3, 4 Porous PTFE film 5, 10 PFA film 5a Convex part 6 Rib 7 Roll body 8 Pleated body 11 Deaerator 12 Housing | casing 13 Liquid inflow port 14 Liquid outflow port 15 Exhaust member 16 Air hole 17 Synthetic resin net 18 Hot melt applicator

Claims (11)

  A step of forming a protrusion on the first gas permeable film by discharging a resin on the first gas permeable film; and after the resin of the protrusion is cured, the protrusion is formed on the first gas permeable film. And a step of forming a second gas permeable membrane so as to cover the part.   The method for producing a degassing membrane according to claim 1, wherein the resin of the protruding portion is a hot melt resin.   The method for producing a deaeration membrane according to claim 1 or 2, wherein the protrusion is formed in a rib shape.   The method for producing a deaeration film according to claim 3, wherein the rib-like protrusion is formed by meandering.   The method for producing a deaeration film according to claim 1, wherein the protrusion is formed in a dot shape.   A side surface of the sheet-shaped gas flow path forming material is covered with a degassing membrane manufactured by the method according to any one of claims 1 to 5, and the other side surface is covered with a gas permeable film, thereby the gas flow path forming material. Envelope-like material that contains.   The envelope-like article according to claim 6, wherein a degassing membrane produced by the method according to any one of claims 1 to 5 is used as the gas permeable membrane used for the other side surface.   The protrusion part formed in one side surface of the said gas flow path formation material and the protrusion part formed in the said other side surface are formed in the same position of the front and back of the said gas flow path formation material. Envelope.   The protrusion part formed in one side surface of the said gas flow path formation material and the protrusion part formed in the said other side surface are formed in the position where the front and back of the said gas flow path formation material differ. Envelope.   The deaeration apparatus which accommodated the envelope-shaped object in any one of Claims 6-9 piled up in the spiral form or the pleat form in the housing | casing which has a liquid inflow port and a liquid outflow port.   The deaeration apparatus according to claim 10, wherein the ribs of the protrusions are formed at an angle of 5 to 85 degrees with respect to a liquid flow direction in the casing.

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