JP2006297200A - Degassing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a degassing apparatus which is capable of more promptly detecting liquid leakage than usual and of controlling the invasion of liquid into the side of a decompression device to be connected. <P>SOLUTION: The degassing apparatus is provided with a vacuum chamber with an inflow port and an outflow port in which the liquid to be degassed is circulated and which has a first connection port to be connected with the decompression device, a gas permeable tube which is connected with one end of the inflow port and stored in the vacuum chamber under connection with the other end of the outflow port, and through which the liquid to be degassed entering the inflow port passes the inside and an exhaust pipe having one end connected with the first connection port and the other end arranged to reach the proximity of the bottom of the vacuum chamber. Further, the degassing apparatus is provided with a porous filter permitting permeation of gas and inhibiting permeation of the liquid and arranged in at least one selected from the exhaust pipe and the first connection port so as to block the exhaust passage of the discharge pipe. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a deaeration device for degassing a gas contained in a liquid.

  The dissolved gas in the liquid causes corrosion of the pipe body through which the liquid flows, a decrease in pressure and heat exchange rate due to the generation of bubbles, and uneven application of the liquid due to the generated bubbles. For this reason, deaeration is required depending on the usage method and purpose of the liquid.

For deaeration of the liquid (liquid to be deaerated), for example, a deaeration device (see FIG. 7) disclosed in Patent Document 1 can be used. 7 includes a gas permeable tube 103 accommodated in a vacuum chamber 102 having an inlet 111 and an outlet 112 for a liquid to be degassed, and both ends of the gas permeable tube 103 are respectively connected to the inlet. 111 and the outlet 112. In addition, a vacuum pulling tube 104 reaching the bottom of the decompression chamber 102 is attached to the decompression chamber 102, and the vacuum pulling tube 104 is connected to a vacuum pulling port 113 included in the decompression chamber 102. In such a deaeration device 101, the liquid to be degassed flows from the inlet 111 to pass through the gas permeable tube 103, and the inside of the decompression chamber 102 is decompressed by the decompression device connected to the vacuum suction port 113. Thus, the liquid to be deaerated can be deaerated.
JP-A-11-333206

  When liquid leakage occurs in the decompression chamber, it becomes difficult to perform stable deaeration depending on the amount of liquid leakage. For this reason, when deaeration of the liquid to be deaerated, it is important to detect a liquid leak of a predetermined amount or more as quickly as possible and stop the operation of the deaerator.

  In the deaeration device 101 shown in FIG. 7, the leaked liquid is sucked out of the deaeration device 101 through the vacuuming tube 104, thereby detecting a liquid leak. One end of the evacuation tube 104 is disposed in the vicinity of the bottom of the decompression chamber 102, and the time from when the liquid leakage starts until the leaked liquid is sucked into the evacuation tube 104 is shortened. It is planned. However, in the method of detecting the sucked liquid, there is a limit to shortening the time until the liquid is actually detected by the detector, and a deaeration device that can detect liquid leakage more quickly is required.

  Further, in the deaeration device 101, the leaked liquid is sucked to the decompression device side to detect the fluid leakage. For example, the leakage sensor or the vacuum pump included in the decompression device is protected. A mechanism such as a liquid trap is required on the decompression device side. In particular, in order to use the deaeration device 101 for a liquid that damages the decompression device or precipitates the contained solid content in the decompression device, a more complicated mechanism is required.

  Therefore, an object of the present invention is to provide a deaeration device that can detect liquid leakage promptly and can prevent liquid from entering the decompression device.

  The deaeration device of the present invention includes an inflow port and an outflow port through which a liquid to be degassed flows, a decompression chamber in which a first connection port for connecting a decompression device is formed, and one end portion at the inflow port. A gas permeable tube that is connected and accommodated in the decompression chamber with the other end connected to the outlet, and through which the liquid to be degassed flowing from the inlet passes. And an exhaust pipe disposed so that the other end reaches the vicinity of the bottom in the decompression chamber, and transmits gas and transmits liquid. The porous filter which becomes an obstacle is arranged in at least one selected from the exhaust pipe and the first connection port so as to block the exhaust passage of the exhaust pipe.

  According to the present invention, one end of the exhaust pipe is disposed in the vicinity of the bottom in the decompression chamber, and a porous filter that permeates gas but obstructs liquid permeation is disposed so as to block the exhaust path of the exhaust pipe. By doing so, it is possible to provide a deaeration device capable of detecting liquid leakage promptly and suppressing the intrusion of liquid into the decompression device side.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals are assigned to the same members, and duplicate descriptions may be omitted.

  FIG. 1 shows an example of the deaeration device of the present invention. The deaeration device 1 shown in FIG. 1 includes an inflow port 11 and an outflow port 12 through which the liquid to be degassed flows, and a decompression chamber 2 in which a first connection port 13 for connecting the decompression device is formed. The decompression chamber 2 accommodates a gas permeable tube 3 having one end connected to the inlet 11 and the other end connected to the outlet 12. The gas liquid passes through the inside of the gas permeable tube 3 and then flows out from the outlet 12. Further, the deaeration device 1 is arranged so that one end is connected to the first connection port 13 and the other end (end A shown in FIG. 1) reaches the vicinity of the bottom in the decompression chamber 2. An exhaust pipe 4 is provided, and the inside of the decompression chamber 2 can be decompressed via the exhaust pipe 4. At the end A of the exhaust pipe 4, a porous filter 5 that allows gas to pass but obstructs liquid permeation is disposed so as to block the exhaust path of the exhaust pipe 4. The decompression chamber 2 includes a lid portion 21 and a housing 22, and the lid portion 21 and the housing 22 are fixed to each other so that airtightness in the decompression chamber 2 is maintained.

  In the deaeration device 1, a depressurization device is connected to the first connection port 13, and the degassed liquid is circulated in the gas permeable tube 3 in a state where the depressurization chamber 2 is depressurized to a predetermined pressure. The liquid to be deaerated can be deaerated.

  During the deaeration process, if the end A of the exhaust pipe 4 enters below the liquid level of the liquid staying at the bottom in the decompression chamber 2 due to liquid leakage, gas permeation to the exhaust pipe 4 is not performed. Instead, the permeation of the liquid into the exhaust pipe 4 is hindered, and the air pressure in the exhaust pipe 4 and the decompression device varies. In the deaeration device 1 of the present invention, it is possible to detect liquid leakage due to such a pressure fluctuation. Liquid leak detection due to fluctuations in atmospheric pressure can be performed more quickly than when sucked liquid is detected, especially when the liquid leak rate is low or the amount of liquid leak to be detected is small. The effect is great.

  Further, it is easier to detect atmospheric pressure fluctuations than liquid detection, and the detection mechanism provided in the decompression device can be further simplified. For example, the deaeration process may be stopped by disposing a pressure gauge on the decompression line of the decompression apparatus connected to the deaeration apparatus 1 and detecting the fluctuation of the pressure gauge. As will be described later, a detection mechanism such as a pressure gauge can be disposed on the deaeration device 1 side.

  Furthermore, in the deaeration device 1, the arrangement of the porous filter 5 can suppress the intrusion of liquid into the decompression device side, so that the mechanism on the decompression device side can be further simplified. In particular, the effect is large when the liquid to be deaerated is a liquid that damages the decompression device or precipitates the contained solid content in the decompression device.

  The porous filter 5 may be an obstacle to the permeation of the liquid, but it is preferable that the porous filter 5 does not substantially permeate the liquid. The occurrence of fluctuations in atmospheric pressure due to liquid leakage can be more reliably performed, and liquid can be more reliably prevented from entering the decompression device.

  The specific structure of the porous filter 5 is not specifically limited, For example, what is necessary is just a porous filter containing the porous film | membrane of a fluororesin or polyolefin resin. Since it is excellent in liquid repellency, it is preferable to include a porous film of fluororesin, and it is particularly preferable to include a porous film of polytetrafluoroethylene (PTFE). The fluororesin porous film is excellent in chemical resistance. The porous film of PTFE can be formed by, for example, stretching after forming and rolling a paste containing PTFE particles.

  The porous filter 5 may include a breathable reinforcing layer in addition to the porous film, and the strength of the porous filter 5 can be improved by stacking the reinforcing layers. What is necessary is just to set arbitrarily the lamination | stacking number of the porous membrane and the reinforcement layer which the porous filter 2 contains, respectively.

  The material and structure of the reinforcing layer are not particularly limited, but it is preferable to have better air permeability than the porous membrane. For the reinforcing layer, for example, a woven fabric, a nonwoven fabric, a mesh, a net, a sponge, a foam, a foam, a porous body, or the like made of resin or metal may be used. The specific material used for the reinforcing layer may be selected according to the type of liquid to be deaerated.

  The reinforcing layer may be bonded to the porous film, and the bonding may be performed by a technique such as adhesive laminating, heat laminating, heat welding, or ultrasonic welding.

  The porous filter 5 may be subjected to liquid repellent treatment (water repellent treatment and / or oil repellent treatment), and the liquid repellent treatment can further suppress the intrusion of liquid into the decompression device side. The liquid repellent treatment may be performed by, for example, applying a substance having a small surface tension to the porous filter 5 and curing it after drying. As the liquid repellent used for the liquid repellent treatment, for example, a solution containing a polymer material having a perfluoroalkyl group may be used. Application of the liquid repellent to the porous filter 5 may be performed by an impregnation method or a spray method, which are general techniques for liquid repellent treatment.

  Although the thickness of the porous filter 5 is not specifically limited, Usually, it is the range of 50 micrometers-10 mm.

  The porosity and average pore diameter of the porous filter 5 are not particularly limited, but in order to obtain a porous filter through which liquid does not substantially permeate, the average pore diameter is, for example, in the range of 0.01 μm to 10 μm. The range of 0.5 μm to 5 μm is preferable. For example, the porosity may be in the range of 10% to 90%, and preferably in the range of 30% to 80%.

  The position where the porous filter 5 is disposed is not particularly limited as long as it is at least one selected from the exhaust pipe 4 and the first connection port 13, but in order to more surely generate the fluctuation of atmospheric pressure due to liquid leakage. Is preferably disposed inside the exhaust pipe 4, and in particular, an end of the exhaust pipe 4 opposite to the end connected to the first connection port 13 (near the bottom in the decompression chamber 2). Arranged end: It is more preferable that the end is disposed at the end A) shown in FIG.

  The arrangement method of the porous filter 5 at the end A of the exhaust pipe 4 is not particularly limited. For example, as shown in FIG. 2, the porous filter 5 may be arranged at the tip of the exhaust pipe 4, As shown in FIG. 3 or FIG. 4, a porous filter 5 may be disposed in the exhaust pipe 4. In order to detect liquid leakage more quickly, a porous filter 5 is preferably disposed at the tip of the exhaust pipe 4.

  The porous filter 5 only needs to be fixed to the exhaust pipe 4 by a technique such as heat welding, ultrasonic welding, or adhesion using an adhesive.

  The structure and configuration of the exhaust pipe 4 are not particularly limited, and may be set arbitrarily including its shape.

  The exhaust pipe 4 may be made of a material having chemical resistance to the liquid to be degassed, such as PTFE, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, ethylene-tetrafluoroethylene copolymer, A fluororesin such as polychlorotrifluoroethylene or a polyolefin such as polyethylene or polypropylene may be used.

  A general method may be used as a method of connecting the exhaust pipe 4 to the first connection port 13.

  What is necessary is just to set arbitrarily the distance of the edge part A of the exhaust pipe 4 and the bottom part in the decompression chamber 2 according to the amount of liquid leaks etc. which should be detected. From the viewpoint of ensuring the deaeration capability until the deaeration device 1 stops even when the liquid leaks, the tip of the exhaust pipe 4 should be positioned at the bottom of the decompression chamber 2 rather than the lower end of the gas permeable tube 3. Is preferred. In this case, the liquid leakage can be detected before the gas permeable tube 3 is immersed in the leaked liquid.

  The gas permeable tube 3 may be a tube generally used for a deaeration device. Specifically, for example, PTFE, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, ethylene-tetrafluoroethylene copolymer, tubes made of fluororesins such as polychlorotrifluoroethylene, polyolefins such as polyethylene and polypropylene What is necessary is just to use the tube which consists of a kind. In order to increase the membrane area per unit volume, a tube in which a large number of hollow fiber bodies are converged is preferable. In this case, the diameter of one hollow fiber body is usually several tens of μm to the inner diameter. It is in the range of several millimeters, and the number of focusing is usually in the range of several to several hundreds.

  Although the shape in which the gas permeable tube 3 is accommodated in the decompression chamber 2 is not particularly limited, from the viewpoint of improving the deaeration capability of the deaeration device 1, as shown in FIG. Preferably it is.

  A general method may be used to connect the gas permeable tube 3 to the outlet 11 and the inlet 12. For example, as shown in FIG. 5, after fixing the metal fitting 55 to the end of the gas permeable tube 3 using a wedge 52 and a cap nut 51, the metal fitting 55 to which the gas permeable tube 3 is fixed, What is necessary is just to fix to the opening part of the decompression chamber 2 using the O-ring 53 and the nut 54. FIG.

  The structure and configuration of the decompression chamber 2 are not particularly limited as long as it can withstand the pressure difference between the inside of the chamber and the external environment. For example, the vacuum chamber 2 may be formed using metal (especially stainless steel is preferable because of its excellent chemical resistance), glass, plastic, etc., and fluororesin or polyolefin is usually used as the plastic.

  Although the decompression chamber 2 shown in FIG. 1 is comprised by the cover part 21 and the housing 23, the method of fixing the cover part 21 and the housing 23 mutually is not specifically limited.

  Another example of the deaeration device 1 of the present invention is shown in FIG. The deaeration device 1 shown in FIG. 6 has the same configuration as the deaeration device 1 shown in FIG. 1, but the second connection port 14 is formed in the lid portion 21 of the decompression chamber 2.

  In the deaeration device 1 of the present invention, when the end A of the exhaust pipe 4 enters below the liquid level of the liquid staying at the bottom in the decompression chamber 2 due to liquid leakage during the deaeration process, Not only does the pressure inside the apparatus fluctuate, but the pressure inside the decompression chamber 2 also fluctuates (since exhaust through the exhaust pipe 4 is not performed, the pressure inside the decompression chamber 2 increases). In the deaeration device 1 as shown in FIG. 6, it is possible to detect liquid leakage by connecting a device for measuring the pressure in the decompression chamber 2, for example, a pressure gauge, to the second connection port 14. The detection mechanism disposed on the decompression device side can be simplified. By optimizing the pressure measuring device connected to the second connection port 14, it is possible to omit the detection mechanism arranged on the pressure reducing device side.

  In the deaeration device 1 of the present invention, a plurality of such second connection ports 14 may be formed, and any device and / or member can be connected to each connection port.

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

  In this example, leakage detection between the case where a porous filter made of a PTFE porous membrane is arranged at one end of the exhaust pipe (Example sample) and the case where it is not arranged (Comparative example sample). And the presence or absence of intrusion of leaked liquid into the decompression device side was evaluated.

  A method for manufacturing each sample will be described.

(Example sample)
First, a vacuum chamber made of stainless steel (with an internal volume of 2400 cm ³ and an inflow port, an outflow port, a first connection port and a second connection port formed in the lid) was prepared, and the prepared decompression chamber was A gas permeable tube in which 130 hollow fiber bodies (inner diameter: 1.0 mm, thickness: 0.13 mm, length: 5 m) made of PTFE were converged was accommodated in a multi-coil shape. When accommodating the gas permeable tube, one end thereof was connected to the outflow port and the other end was connected to the inflow port by the mechanism shown in FIG.

  Next, an exhaust pipe (made of PTFE: inside diameter 4 mm) in which a porous filter composed of a porous PTFE membrane (average pore diameter 0.5 μm, porosity 80%, thickness 150 μm) is fixed to one end is prepared and prepared. The exhaust pipe was accommodated in a vacuum chamber. When accommodating the exhaust pipe, the end opposite to the end (end A) to which the porous filter is fixed is connected to the first connection port, and the end A and the bottom in the vacuum chamber are connected. The distance was 3 mm.

  Next, a pressure gauge was connected to the second connection port to produce a deaeration device 1 as shown in FIG.

(Comparative example sample)
First, a vacuum chamber made of stainless steel (with an internal volume of 2400 cm ³ , an inflow port, an outflow port, and a first connection port formed in the lid) was prepared, and in the prepared decompression chamber, the same as the example sample The gas permeable tube was accommodated in a multiple coil shape. When accommodating the gas permeable tube, one end thereof was connected to the outflow port and the other end was connected to the inflow port by the mechanism shown in FIG.

  Next, an exhaust pipe similar to the example sample (however, a porous filter is not arranged) is prepared, and the prepared exhaust pipe is accommodated in a decompression chamber to produce a deaeration device. It was. When accommodating the exhaust pipe, one end of the exhaust pipe was connected to the first connection port, and the distance between the other end and the bottom of the decompression chamber was 3 mm.

  After connecting the 1st connection port in each deaerator sample produced in this way to a vacuum pump, when pure water was poured from an inflow port and the inside of a decompression chamber was decompressed, both an example sample and a comparative example sample The vacuum pressure of about −720 mmHg (gauge pressure) could be maintained in the vacuum chamber. In addition, the liquid trap which can visually observe the inside was arrange | positioned between the comparative example sample and the vacuum pump.

  Next, the liquid flow and pressure reduction were temporarily stopped, and after opening a hole in one of the 130 hollow fiber bodies, the liquid flow and pressure reduction were performed again. Due to fluctuations in the pressure gauge connected to the second connection port, in the comparative sample, liquid leakage is detected by confirming the pure water sucked into the liquid trap placed between the sample and the vacuum pump. We were able to. At this time, in the example sample, it was possible to confirm the fluctuation of the pressure gauge almost simultaneously with the end A of the exhaust pipe being below the surface of the pure water staying in the decompression chamber, whereas in the comparative example sample, The pure water sucked into the exhaust pipe is not accommodated in the liquid trap until about 30 seconds have elapsed after the end A of the exhaust pipe becomes below the surface of the pure water staying in the decompression chamber. It was.

  In the example sample, no entry of pure water into the exhaust pipe was confirmed, but in the comparative sample, a large amount of pure water was sucked into the liquid trap.

  ADVANTAGE OF THE INVENTION According to this invention, the deaeration apparatus which can detect a liquid leak quickly and can suppress the penetration | invasion of the liquid to the decompression device side can be provided.

It is sectional drawing which shows typically an example of the deaeration apparatus of this invention. It is sectional drawing which shows typically an example of the arrangement | positioning method of the porous filter in the deaeration apparatus of this invention. It is sectional drawing which shows typically another example of the arrangement | positioning method of the porous filter in the deaeration apparatus of this invention. It is sectional drawing which shows typically another example of the arrangement | positioning method of the porous filter in the deaeration apparatus of this invention. It is sectional drawing which shows an example of the connection method of the gas permeable tube in the deaeration apparatus of this invention. It is sectional drawing which shows typically another example of the deaeration apparatus of this invention. It is sectional drawing which shows an example of the conventional deaeration apparatus typically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Deaeration device 2 Depressurization chamber 3 Gas permeable tube 4 Exhaust pipe 5 Porous filter 11 Inlet 12 Outlet 13 1st connection port 14 2nd connection port 21 Lid part 22 Housing 51 Cap nut 52 Wedge 53 O-ring 54 Nut 55 Metal fitting 101 Deaeration device 102 Decompression chamber 103 Gas permeable tube 104 Vacuum evacuation tube 111 Inlet 112 Outlet 113 Vacuum evacuation port

Claims (6)

An inflow port and an outflow port through which the liquid to be degassed flows, and a decompression chamber in which a first connection port for connecting a decompression device is formed;
One end is connected to the inflow port, and the other end is connected to the outflow port, and is accommodated in the decompression chamber. A gas permeable tube passing through;
An exhaust pipe disposed so that one end is connected to the first connection port and the other end reaches near the bottom in the decompression chamber;
A porous filter that transmits gas and obstructs the permeation of liquid is disposed in at least one selected from the exhaust pipe and the first connection port so as to block the exhaust passage of the exhaust pipe. A deaeration device characterized by comprising:   The deaeration apparatus according to claim 1, wherein the porous filter does not substantially transmit liquid.   The deaeration apparatus according to claim 1, wherein the porous filter is disposed at the other end of the exhaust pipe.   The deaeration apparatus according to claim 1, wherein the porous filter includes a porous film of a fluororesin.   The deaerator according to claim 4, wherein the fluororesin is polytetrafluoroethylene.   The deaeration device according to claim 1, wherein a second connection port for connecting a device for measuring the pressure in the decompression chamber is further formed in the decompression chamber.

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