JP2010264405A - Degassing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely fix a degassing element to a vacuum chamber. <P>SOLUTION: The degassing device 100 is provided with the vacuum chamber 3, the degassing element 4, a connector 9 and a locking member 14. The connector 9 includes a first part 9a engaged with a connection port 2 of the vacuum chamber 3 and a second part 9b projected from the connection port 2. The outer peripheral surface of the second part 9b has a non-circular cross-sectional profile. The degassing element 4 has a gas permeating tube 6 and a connection piece 8 covering the end part of the gas permeating tube 6. A welded part 20 is formed to be astride the connection piece 8 and the connector 9. The locking member 14 has a holding hole 18 having a shape corresponding to the second part 9b of the connector 9. The locking member 14 is fixed to the vacuum chamber 3 while inserting the second part 9b into the holding hole 18. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a deaeration device.

  The dissolved gas in the liquid causes piping corrosion, an increase in pressure loss, a decrease in heat exchange rate, and uneven application of liquid. Therefore, it is necessary to remove dissolved gas from the liquid according to the usage method and purpose of the liquid. As a degassing device for removing dissolved gas from a liquid, for example, there is the one shown in FIG. According to the deaeration device 101, a liquid is caused to flow through the deaeration element 103 disposed in the vacuum chamber 102. Thereby, the dissolved gas can be removed from the liquid.

  The deaeration element 103 is typically made of a number of hollow fibers that are gas permeable. Joining pieces 106 are respectively provided at both ends of the deaeration element 103. A connection member 104 is fixed to the upper lid of the vacuum chamber 102. A joining piece 106 of the deaeration element 103 is fitted to the connection member 104 via the ferrule 107. The connecting member 104, the ferrule 107, and the joining piece 106 are integrally tightened with a nut 108 so that the joining piece 106 does not come off from the connecting member 104. With such a structure, the deaeration element 103 is fixed to the vacuum chamber 102 via the connection member 104.

  If the tightening force (torque) of the nut 108 is too weak, the deaeration element 103 may be detached from the connection member 104. Conversely, if the tightening force of the nut 108 is too strong, the nut 108 may be damaged. Further, since the deaeration element 103 and the connection member 104 are fastened in a so-called caulking structure using the ferrule 107 and the nut 108, high dimensional accuracy is required for the joining piece 106 and the connection member 104. This hinders reduction of component costs and improvement of product yield.

  On the other hand, in Patent Document 2, a connecting member and a joining piece are joined using resin powder having heat-fusibility, and the connecting member is thermally welded to a vacuum chamber to fix the deaeration element to the vacuum chamber. The technology is described. According to this technique, the deaeration element, the connection member, and the vacuum chamber can be fixed to each other without adopting a caulking structure. The accuracy required for each part is not as high as required for the caulking structure.

Japanese Patent No. 3585077 JP 2007-319854 A

  However, the connection structure of the deaeration device described in Patent Document 2 has room for further improvement. An object of the present invention is to securely fix a deaeration element to a vacuum chamber.

That is, the present invention
A vacuum chamber having a connection port;
A first portion fitted in the connection port; and a second portion protruding from the connection port outside the vacuum chamber, wherein the outer peripheral surface of the second portion has a non-circular cross-sectional profile. A cylindrical connector attached to the connection port;
A deaeration element disposed in the vacuum chamber, having a gas permeable tube and a joining piece that covers an end of the gas permeable tube and is fixed to the vacuum chamber via the connector When,
A welded portion formed in a manner straddling the joining piece and the connector;
The vacuum chamber has a holding hole having a shape corresponding to the non-circular cross-sectional profile, and the second part is inserted into the holding hole so as to prevent a change in posture of the first part with respect to the connection port. A locking member fixed to
A deaeration device is provided.

  According to the present invention, the connector holding the joining piece of the deaeration element is fitted into the connection port of the vacuum chamber. The joining piece of the deaeration element is welded to the connector. The connector includes a first part fitted in the connection port of the vacuum chamber and a second part protruding from the connection port. The outer peripheral surface of the second portion has a non-circular cross-sectional profile. A locking member is provided outside the vacuum chamber so that the connector does not come off the vacuum chamber. The locking member has a holding hole having a shape corresponding to a non-circular cross-sectional profile. With the second part of the connector inserted into the holding hole, the locking member is fixed to the vacuum chamber. Thereby, the change of the attitude | position of the 1st part with respect to a connection port is blocked, ie, it prevents that a connector remove | deviates from a connection port. According to such a structure, the deaeration element can be reliably fixed to the vacuum chamber without using a caulking structure.

The longitudinal cross-sectional view of the deaeration apparatus concerning one Embodiment of this invention Top view of the vacuum chamber top lid Longitudinal section of the upper lid Side view of upper lid Side view of the first connector Cross section of the first connector Top view of the locking member Longitudinal sectional view of the locking member Perspective view of the deaeration element joint piece Schematic enlarged view of weld Side view of the second connector Process diagram showing welding method Longitudinal section of a conventional deaerator

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, the deaeration device 100 of this embodiment includes a vacuum chamber 3, a deaeration element 4, a first connector 9, a second connector 12, and a locking member 14. An end of the deaeration element 4 is welded to the first connector 9, and the deaeration element 4 is fixed to the vacuum chamber 3 via the first connector 9. In order to maintain the attachment state of the first connector 9 to the vacuum chamber 3, a locking member 14 is provided. A liquid is allowed to flow through the deaeration element 4 while evacuating the vacuum chamber 3 with a decompression device such as a vacuum pump. Thereby, the dissolved gas can be removed from the liquid.

  The vacuum chamber 3 includes a cylindrical main body 3a, a lower lid 3b, and an upper lid 3c. The openings at both ends of the main body 3a are closed by the lower lid 3b and the upper lid 3c so that the airtightness in the vacuum chamber 3 can be maintained. As shown in FIGS. 2A and 2B, the upper lid 3c is provided with two connection ports 2 penetrating the upper lid 3c in the thickness direction. One connection port 2 is an inlet for liquid to be degassed, and the other connection port 2 is an outlet for liquid that has been degassed. One end and the other end of the deaeration element 4 are connected to these connection ports 2 from the inside of the vacuum chamber 3, respectively.

  The upper lid 3c is further provided with a suction port 5, a recess 11 and a screw hole 16. The suction port 5 is connected to a decompression device for evacuation. The recess 11 is a part for accommodating the locking member 14 and is provided corresponding to each of the two connection ports 2. The screw hole 16 is used to screw the locking member 14 to the upper lid 3c. As shown in FIG. 2C, a male screw 17 (taper screw) is formed on the outer peripheral surface of the upper lid 3c. An upper lid 3c is screwed to the main body 3a so that the airtightness in the vacuum chamber 3 is maintained. This structure is the same for the lower lid 3b. The structure for fixing the lids 3b and 3c to the main body 3a is not limited. For example, the lids 3b and 3c may be welded to the main body 3a.

  As a material of the vacuum chamber 3, a resin, preferably a thermoplastic resin such as a fluororesin or a polyolefin can be used. Part or all of the vacuum chamber 3 may be made of other materials, such as metal or glass. Suitable metals include stainless steel.

  As shown in FIGS. 1 and 5, the deaeration element 4 has a tube bundle 10 and a joining piece 8. The tube bundle 10 is composed of a plurality of gas permeable tubes 6. The joining piece 8 covers the end of the tube bundle 10. The number of gas permeable tubes 6 in the tube bundle 10 is usually in the range of several to several hundreds. The liquid flows through each gas permeable tube 6. In FIG. 1, the deaeration element 4 has a U-shape, but the deaeration element 4 may have another shape. For example, the deaeration element 4 may be wound in a coil shape.

  The gas permeable tube 6 includes polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene, and the like. A tube made of fluororesin or a tube made of polyolefin such as polyethylene or polypropylene can be used. Typically, as the gas permeable tube 6, a hollow fiber made of a resin porous membrane is used. The gas permeable tube 6 usually has an inner diameter in the range of several tens of μm to several mm. The deaeration element 4 only needs to include at least one gas permeable tube 6.

  The plurality of gas permeable tubes 6 can be bundled according to a known method. For example, the tube bundle 10 can be formed if the ends of the gas permeable tubes 6 are bound to each other using a thermoplastic resin having heat-fusibility. As the thermoplastic resin having heat-fusibility, fluororesins such as PFA, tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ETFE and the like can be used.

  The joining piece 8 plays a role of covering the end of the tube bundle 10 and a role of fixing the deaeration element 4 to the first connector 9. In the present embodiment, a member having a cylindrical shape is used as the joining piece 8. As the material of the joining piece 8, a thermoplastic resin can be suitably used. Examples of the thermoplastic resin include fluororesins such as PTFE, PFA, ETFE, and polychlorotrifluoroethylene (PCTFE). PFA is recommended because it is easy to cover the tube bundle 10 due to its heat shrinkability and can hold the tube bundle 10 reliably.

  As shown in FIG. 1, the first connector 9 is a member having a cylindrical inner peripheral surface. The joining piece 8 of the deaeration element 4 is inserted into the first connector 9 and is held by the first connector 9. A joining piece 8 is inserted into the first connector 9 from the inside of the vacuum chamber 3. The joining piece 8 is fixed to the first connector 9 by heat welding. The first connector 9 is attached to the connection port 2 while maintaining the state where the joining piece 8 is inserted. That is, the deaeration element 4 is fixed to the vacuum chamber 3 via the first connector 9. According to such a structure, the deaeration element 4 can be reliably fixed to the vacuum chamber 3 without using a caulking structure or an O-ring. The caulking structure and the O-ring are not essential and may be provided.

  Specifically, the first connector 9 includes a first portion 9a and a second portion 9b. The first portion 9 a is a portion fitted into the connection port 2, and the second portion 9 b is a portion protruding from the connection port 2 outside the vacuum chamber 3. Specifically, the second portion 9 b penetrates the locking member 14 and protrudes above the locking member 14. As shown to FIG. 3A, the external thread is formed in the outer peripheral surface of the 1st part 9a. A female screw corresponding to the male screw is formed on the inner peripheral surface 13 (see FIG. 2B) of the connection port 2 of the upper lid 3c. That is, the first connector 9 is screwed into the connection port 2, whereby the first connector 9 is fixed to the upper lid 3 c.

  In the present embodiment, the male screw formed on the outer peripheral surface of the first portion 9a and the screw formed on the inner peripheral surface 13 of the connection port 2 of the upper lid 3c are each a tapered screw. A fluororesin seal tape may be interposed between the first portion 9 a of the first connector 9 and the connection port 2. If a taper screw and seal tape are used in combination, air leakage can be prevented more reliably. Further, since the taper screw is easier to loosen than the straight screw, the significance of providing the locking member 14 increases.

  On the other hand, as shown in FIG. 3B, the outer peripheral surface of the second portion 9b has a non-circular cross-sectional profile. When the second portion 9b has such a shape, the first connector 9 can be prevented from rotating only by fitting the second portion 9b into the holding hole 18 of the locking member 14. That is, it can prevent that the 1st connector 9 rotates and the 1st part 9a loosens.

  As long as the rotation of the first connector 9 can be prevented, the shape of the outer peripheral surface of the second portion 9b is not particularly limited. Specifically, as “non-circular”, one shape selected from the group consisting of a polygon, an ellipse, a combination of a plurality of curves having different curvature radii, and a combination of a straight line and a curve is used. Can be adopted. In the present embodiment, the outer peripheral surface of the second portion 9b has an oval cross-sectional profile. The oval shape is an example of a shape formed by a combination of a straight line and a curved line, and has an advantage that it can be easily formed by cutting a part of a cylindrical member.

  As shown in FIGS. 4A and 4B, the locking member 14 is a disc-shaped member. The locking member 14 is formed with a holding hole 18 having a shape corresponding to a non-circular cross-sectional profile in the second portion 9 b of the first connector 9. The size of the holding hole 18 is adjusted to be slightly larger than that of the second portion 9b so that the second portion 9b of the first connector 9 can be inserted. As shown in FIG. 1, the locking member 14 is fixed to the vacuum chamber 3 with the second portion 9 b inserted into the holding hole 18 so as to prevent a change in the posture of the first portion 9 a with respect to the connection port 2. Yes. A screw hole 19 is also formed in the locking member 14 so that the locking member 14 can be fixed to the upper lid 3c with the screw 7. Instead of the screws 7, other stoppers such as bolts and keys can be used. Further, the locking member 14 may be welded to the upper lid 3c.

  As shown in FIG. 1, the second connector 12 includes a large-diameter portion 12a and a small-diameter portion 12b. The large diameter portion 12 a is a portion joined to the first connector 9. The small diameter portion 12 b is a portion for connecting a tube for supplying the liquid to be deaerated to the deaeration element 4 or a tube for recovering the degassed liquid from the deaeration element 4. The large diameter portion 12 a is thermally welded to the end face of the first connector 9. Specifically, the second connector 12 is butt welded to the second portion 9 b of the first connector 9. In this way, the second connector 12 can be easily joined to the first connector 9 without using a caulking structure or an O-ring. It is also possible to omit the second connector 12 and connect the above-mentioned tube directly to the first connector 9.

  In the present embodiment, the deaeration element 4 is thermally welded to the first connector 9, and the second connector 12 is also thermally welded to the first connector 9. Specifically, as shown in FIG. 6, the deaeration element 4 is inserted into the first connector 9 until the end surface of the second portion 9 b and the end surface of the joining piece 8 are flush with each other. And the welding part 20 is formed in the form straddling the joining piece 8 of the deaeration element 4 and the 2nd part 9b of the 1st connector 9 regarding the radial direction of the 1st connector 9. As shown in FIG. Further, the welded portion 20 extends between the first connector 9 and the second connector 12 in the axial direction (longitudinal direction) of the first connector 9. That is, the welded portion 20 straddles the end surface of the second portion 9 b, the end surface of the joining piece 8, and the end surface of the second connector 12. If it does in this way, deaeration element 4, the 1st connector 9, and the 2nd connector 12 can be joined firmly mutually.

  In the present embodiment, each of the first connector 9 and the second connector 12 is made of a resin (specifically, a thermoplastic resin). As long as the weld 20 can be formed, the first connector 9 and the second connector 12 may contain materials other than resin. The type of resin constituting the first connector 9 and the second connector 12 is not particularly limited, and can be selected from those listed above as the resin of the joining piece 8. For example, as a material for the first connector 9 and the second connector 12, a fluororesin can be suitably used.

  That is, a fluororesin can be suitably used as at least one selected from the group consisting of a resin that constitutes the first connector 9, a resin that constitutes the second connector 12, and a resin that constitutes the joining piece 8. These resins may be different from each other, but by using the same resin (for example, PFA), strong bonding by heat welding becomes possible.

  In the present embodiment, the inner diameter and the outer diameter of the first connector 9 are equal to the inner diameter and the outer diameter of the large-diameter portion 12b of the second connector 12, respectively. In this way, butt welding with high accuracy becomes possible. However, these may be different from each other. For example, the inner diameter of the large-diameter portion 12 b of the second connector 12 can be made larger than the inner diameter of the first connector 9.

  In addition, as shown in FIG. 7, if the convex part 12c is provided in the end surface of the 2nd connector 12 before welding, it will become easy to abut the 2nd connector 12 to the 1st connector 9, and to weld. Further, if the convex portion 12c is provided, a thick welded portion 20 (so-called build-up welded portion) can be formed based on the fact that the convex portion 12c is melted and solidified as shown in FIG. Strength is improved.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the examples shown below.

  First, as the gas permeable tube 6, four PTFE tubes having an inner diameter of 0.95 mm, a thickness of 0.11 mm, and a length of 300 mm were prepared. After applying PFA powder to the outer peripheral surfaces of both ends of the four PETF tubes, both ends were sandwiched between molds and heated and pressurized at 370 ° C. for 5 minutes. As a result, four PTFE tubes were bonded to each other to obtain a tube bundle 10. Next, a cylindrical PFA pipe (outer diameter 6 mm) having heat shrinkability was prepared as the joining piece 8. After applying PFA powder to the inner peripheral surface of the PFA pipe, the PFA pipe was attached to the end of the tube bundle 10. The end of the tube bundle 10 and the PFA pipe were heated to integrate the PFA pipe with the tube bundle 10. Thus, the deaeration element 4 having an outer diameter of 6 mm and an effective length of 200 mm was obtained.

  The first connector 9 (inner diameter 6 mm) described with reference to FIGS. 3A and 3B was produced. PFA was used as the material for the first connector 9. A PT1 / 8 taper male screw was formed on the outer peripheral surface of the first portion 9a. The second portion 9b was formed so that the cross-sectional profile of the outer peripheral surface was oval.

  A polypropylene cylindrical pipe having an inner diameter of 52 mm and a length of 130 mm was prepared as the main body 3a. Tapered female screws having a taper angle of 60 ° and a pitch of 2.0 mm were formed on the inner peripheral surface in the vicinity of the opening of the main body 3a. Next, a polypropylene plate was extruded and cut to produce a lower lid 3b and an upper lid 3c. A tapered male screw having the same taper angle and screw pitch as the main body 3a was formed on the outer peripheral surface of each lid. As described with reference to FIGS. 2A and 2B, the upper lid 3 c is provided with the connection port 2, the suction port 5, the recess 11, and the screw hole 16. An Rc1 / 8 taper female thread was formed on the inner peripheral surface of the connection port 2. An Rc1 / 8 taper female thread was also formed on the inner peripheral surface of the suction port 5.

  The 2nd connector 12 demonstrated with reference to FIG. 7 was produced. PFA was used as the material for the second connector 12. The inner diameter of the large diameter portion 12a was set to 6 mm.

  Using a polypropylene plate, the locking member 14 (fixed plate) described with reference to FIGS. 4A and 4B was produced by cutting.

  A seal tape (No. 95 manufactured by Nitto Denko Corporation) was wound around the first connector 9 and screwed into the upper lid 3c. After the joining piece 8 of the deaeration element 4 was inserted into the first connector 9 from the inside of the vacuum chamber, the upper lid 3c and the lower lid 3b were assembled to the main body 3a. The end face of the joining piece 8 and the end face of the first connector 9 were flush with each other. Next, the locking member 14 was fitted into the upper lid 3c so that the first connector 9 was not loosened, and was fixed with a stainless steel screw 7.

  Next, as shown in FIG. 8, the first connector 9 and the second connector 12 are disposed to face each other via a plate-like far infrared heater 24. The heater 24 was energized to melt the end faces of the first connector 9, the joining piece 8, and the second connector 12 over 2 minutes. During energization, the vacuum chamber 3 and the locking member 14 were covered with the heat insulating material 22. Thereafter, the heater 24 was removed, and the second connector 12 was abutted against the first connector 9. The first connector 9, the joining piece 8 of the deaeration element 4, and the second connector 12 were joined to each other by slow cooling at room temperature for 2 minutes. In this way, the deaerator 100 having the structure shown in FIG. 1 was manufactured.

  A degassing experiment was performed using the manufactured degassing apparatus 100. First, the inside of the vacuum chamber 3 of the deaerator 100 was evacuated to a pressure of 4 kPa by a vacuum pump. While maintaining this pressure, a cycle of stopping water supply for 60 seconds after supplying water to the deaeration element 4 through the second connector 12 at a water pressure of 0.3 MPa for 10 seconds was repeated 100,000 times. After 100,000 cycles, the vacuum pump was stopped and the change in the degree of vacuum inside the vacuum chamber 3 was examined. Even after the vacuum pump was stopped, the degree of vacuum in the vacuum chamber 3 hardly changed, and the bonding state between the first connector 9 and the vacuum chamber 3 was good. Further, the vacuum chamber 3 was opened to check for water leakage. As a result, water did not leak into the vacuum chamber 3.

2 Connection port 3 Vacuum chamber 3c Upper cover 4 Deaeration element 6 Gas permeable tube 7 Screw 8 Joint piece 9 First connector 9a First part 9b Second part 10 Tube bundle 12 Second connector 14 Loosening prevention member 18 Holding hole 20 Welding Part 100 deaerator

Claims (9)

A vacuum chamber having a connection port;
A first portion fitted in the connection port; and a second portion protruding from the connection port outside the vacuum chamber, wherein the outer peripheral surface of the second portion has a non-circular cross-sectional profile. A cylindrical connector attached to the connection port;
A deaeration element disposed in the vacuum chamber, having a gas permeable tube and a joining piece that covers an end of the gas permeable tube and is fixed to the vacuum chamber via the connector When,
A welded portion formed in a manner straddling the joining piece and the connector;
The vacuum chamber has a holding hole having a shape corresponding to the non-circular cross-sectional profile, and the second part is inserted into the holding hole so as to prevent a change in posture of the first part with respect to the connection port. A locking member fixed to
A degassing device. A screw is formed on the outer peripheral surface of the first part, and a female screw is formed on the inner peripheral surface of the connection port,
The deaeration device according to claim 1, wherein the connector is screwed into the connection port. The male screw and the female screw are each a tapered screw,
The deaeration apparatus according to claim 2, wherein a seal tape made of a fluororesin is interposed between the first part and the connection port. The vacuum chamber includes a cylindrical main body and a lid that closes an opening of the main body,
The connection port is provided in the lid;
The deaeration device according to any one of claims 1 to 3, wherein the loosening prevention member is constituted by a disk-like member and is fixed to the lid by a stopper such as a bolt or a screw.   The deaeration device according to any one of claims 1 to 4, further comprising a second connector that is butt welded to the second portion of the connector. The end surface of the second part and the end surface of the joining piece are flush with each other,
The deaeration apparatus according to claim 5, wherein the welded portion straddles an end surface of the second portion, an end surface of the joining piece, and an end surface of the second connector.   The non-circular cross-sectional profile is a cross-sectional profile of one shape selected from the group consisting of a polygon, an ellipse, a combination of a plurality of curves having different radii of curvature, and a combination of a straight line and a curve. The deaeration device according to any one of claims 1 to 6.   The deaeration apparatus according to claim 1, wherein the joining piece and the connector are each made of a thermoplastic resin.   The deaeration apparatus according to claim 8, wherein the thermoplastic resin is a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer.

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