JP2009145120A - Leaking fluid collection structure and fluid leakage detection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a leaking fluid collection structure for collecting fluid leaking from a gap between a stem and a gland packing of a flow control valve; and a fluid leakage detection system for detecting the collected fluid. <P>SOLUTION: In this system, fluid leaking from a gap between a stem 32 and a gland packing 33 flows from a gap 48 formed in the outer circumference of the stem 32 to a communication hole 36 disposed on a packing follower 35. Then, it flows to a circumferential groove 6 of a collecting part 2 disposed along the outer circumference of the packing follower 35 and is collected by a collecting member 1. The collected leaking fluid is drawn out of a takeout opening 9 through a passage 7 from the circumferential groove 6 and detected by being introduced to a sensor 20 installed in a sensor storage part 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fluid collection device that collects fluid leaking from the periphery of a stem that slides or rotates in a flow control valve, and a fluid leakage detection system that detects leakage.

In recent years, due to the need for increasing the cruising distance of fuel cell vehicles, there is a need for hydrogen infrastructure development that can accommodate fuel cell vehicles that use high-pressure hydrogen at a higher pressure of 70 MPa than the conventional 35 MPa. For this reason, the flow rate control valve needs to correspond to a higher pressure of 70 MPa from the conventional 35 MPa.
The flow rate control valve corresponding to the high pressure of 70 MPa is more likely to leak the fluid than the flow rate control valve corresponding to the 35 MPa because the fluid flowing inside the valve is at a high pressure. In particular, when hydrogen is used as the fluid to be adjusted, hydrogen is explosive and dangerous, so it is necessary to reliably detect leakage from the flow control valve.

Conventionally, fluid leakage from the gap between the stem directly connected to the valve body and the gland packing in the flow control valve is estimated from the time the stem has moved according to the valve opening of the valve body and the unit estimated leak amount. It was. (For example, patent document 1). The unit estimated leak amount is calculated from the gap in the packing and the pressure in the flow control valve.
The amount of leakage can also be estimated from the moving distance of the stem that moves according to the valve opening of the valve body and the unit surface area of the stem. This estimates the amount of leakage by which the fluid adhering to the stem surface is pushed out by the reciprocating motion of the stem by calculation.

JP 2001-147171 A

  Since the conventional fluid leakage detection system is configured as described above, there is a problem in that it is not possible to directly measure the amount of fluid leaking from the gap between the stem and the gland packing. For this reason, even if the amount of fluid leakage increases due to, for example, breakage of the gland packing, it could not be detected.

  The present invention has been made to solve the above-described problems, and leaks from the gap between the stem and the gland packing in order to directly detect the amount of fluid leaking from the gap between the stem and the gland packing. An object is to obtain a leaking fluid collecting structure for collecting fluid.

  The leakage fluid collecting structure according to the present invention includes a gland packing that covers the outer peripheral surface of the stem connected to the valve body, a packing follower that inserts the stem and holds the gland packing, and a side that contacts the gland packing of the packing follower. The flow regulating valve has a leakage fluid collecting structure including a packing flange that is fitted to the side and fixes the gland packing in place, and the packing follower is a reduced diameter portion provided on the side that is fitted to the packing flange. And a communication hole that communicates with the outer peripheral surface of the stem, and the collecting member has a flow path that communicates the communication hole formed in the packing follower and the outside outlet, and is fitted to the reduced diameter portion. At the same time, it is sandwiched between a packing flange and a packing follower.

  In the leakage fluid collecting structure according to the present invention, the packing follower has a plurality of communication holes, and the collecting member is connected to the plurality of communication holes and provided with a circumferential groove communicating with the flow path.

  A fluid leakage detection system according to the present invention includes the leakage fluid collection structure described above, and further includes a leakage detection unit that is connected to an extraction port of the collection member and detects the fluid collected by the collection member. Fluid leakage detection system.

  According to this invention, the gland packing that covers the outer peripheral surface of the stem connected to the valve body, the packing follower that presses the gland packing through the stem, and the side that contacts the gland packing of the packing follower are fitted to the opposite side. The leakage follower fluid collecting structure of the flow control valve having a packing flange for fixing the gland packing in place, the packing follower includes a reduced diameter portion provided on the side to be fitted with the packing flange, and a stem outer peripheral surface The collection member has a flow path that connects the communication hole formed in the packing follower and the take-out port to the outside. The collecting member is fitted to the reduced diameter portion and has a packing flange and a packing follower. To obtain a leaking fluid collecting structure of the flow control valve that collects the fluid leaking from the gap between the stem and the gland packing. Kill.

Embodiment 1 FIG.
1 is a cross-sectional view showing a configuration of a leakage fluid collecting structure for a flow control valve according to Embodiment 1 of the present invention. FIG. 2 is an external perspective view showing the leakage fluid collecting structure of the flow control valve according to Embodiment 1 of the present invention. FIG. 1 is a cross-sectional view taken along line AA shown in FIG.
FIG. 3 is an exploded perspective view showing a main part constituting the leakage fluid collecting structure of the flow rate regulating valve according to Embodiment 1 of the present invention. 1 to 3, the same or corresponding parts are denoted by the same reference numerals.

  In the leakage fluid collecting structure of the flow rate control valve 30 shown in FIGS. 1 to 3, the collection member 1 is attached to the flow rate adjustment valve 30 and collects the leaked fluid leaking from the gap between the stem 32 and the gland packing 33. The collection unit 2, the sensor housing 3 to which the sensor (leakage detection unit) 20 for detecting the leakage by measuring the leaked fluid collected by the collection unit 2 is connected, and the collection unit 2 and the sensor housing unit 3 are connected to leak. It has a drawer 4 that draws fluid to the sensor housing 3, and a discharge 5 that discharges the leaked fluid measured by the sensor 20 in the sensor housing 3 to the outside.

  1 to 3 includes a valve body 31 including a valve body (not shown) for adjusting the flow rate of the fluid flowing through the flow control valve 30, and a vertical movement to control the valve opening degree. A stem 32 inserted in a rotatable or rotatable manner and a gland packing 33 for preventing fluid leakage from the valve body 31 to the outside are provided.

  A packing presser 34 and a packing follower 35 for pressing the gland packing 33 are attached to the flow rate control valve 30. The lower part of the packing follower 35 has a cylindrical shape, and a disc spring 37 is arranged inside the cylinder. Further, a reduced diameter portion having a small outer diameter is provided at the upper portion of the cylinder, and a gap portion 48 is provided on the inner peripheral side. Four communication holes 36 are formed in the radial direction at the height position where the gap 48 of the packing follower 35 is provided. The communication hole 36 communicates the outer peripheral surface of the stem 32 and the gap 48 of the packing follower 35, and the number of holes may be one or plural.

  The gland packing 33, the packing presser 34, the packing follower 35, and the disc spring 37 are provided with a hole portion through which the stem 32 is inserted at the center of each portion. The packing flange 38 fixes the gland packing 33 via the packing retainer 34 and the packing follower 35 in a state where the reduced diameter portion of the packing follower 35 and the stem 32 are inserted. The packing flange 38 and the valve body 31 are fastened by a stud bolt 39 and a nut 40. As a result, the gland packing 33 receives a load from the packing follower 35 or the like stacked above and is fixed at a predetermined position to seal the fluid.

  Further, the gap between the packing retainer 34 and the valve main body 31 is sealed by an O-ring 42 that is attached around the outer periphery of the packing retainer 34 as shown in FIG. The gap between the packing follower 35 and the stem 32 is sealed by the seal portion 43 and an O-ring 44 that is circumferentially attached along the outer periphery of the seal portion 43 and an O-ring 47 that is circumferentially attached along the outer periphery of the stem 32. The In FIG. 3, the O-rings 42, 44 and 47 are not shown.

The collecting member 1 is formed with a collecting portion 2 which is a hole having a diameter through which the stem 32 and the packing follower 35 surrounding the stem 32 are inserted. A circumferential groove 6, which is a concave groove having a substantially U-shaped cross section that goes around the inner wall, is formed on the inner wall of the collection portion 2.
A flow path 7 is provided inside the flow path section 4, and the flow path 7 introduces the fluid in the circumferential groove 6 into the sensor accommodating section 3. One flow path 7 is provided at the center of the flow part 4 in the vertical and horizontal directions. In addition, while the circumferential groove 6 connects the four communication holes 38 and communicates with the flow path 7, no matter which communication hole 36 of the plurality of communication holes 36 that penetrates the packing follower 35 flows out, The leaked fluid circulates in the circumferential groove 6 and flows into the flow path 7.

  The sensor accommodating portion 3 of the collecting member 1 is a cylindrical space in which an extraction port 9 is formed. By attaching the sensor 20 inside the cylinder, the sensor 20 detects the leaked fluid introduced from the outlet 9. The sensor 20 accommodated in the sensor accommodating portion 2 may be any sensor that can detect this fluid in accordance with the type of fluid flowing through the flow control valve 30. Further, a rectifying plate 10 to be described later is installed in the sensor housing 3, and the leaked fluid introduced from the take-out port 9 to the sensor housing 3 is sent to the sensing unit 21.

  A space for the discharge portion 5 is formed below the sensor housing portion 3. In addition, a discharge hole 8 is formed in the partition plate that partitions the sensor housing unit 3 and the discharge unit 5. The discharge hole 8 is a hole for discharging the leaked fluid measured by the sensor 20 from below the collecting member 1 to the outside through the discharge unit 5. Further, a filter unit 50 is installed in the discharge unit 5. The filter portion 50 is filled with silica gel, activated carbon, or the like, and a hole portion through which the fluid discharged from the discharge hole 8 is passed is provided on the upper surface. Further, a moisture-permeable waterproof material such as Gore-Tex (registered trademark) is attached to the lower surface of the filter unit 50 to prevent water from entering the filter unit 50 and the sensor storage unit 3 from below. Furthermore, a lid 51 having a hole formed in the center is fitted to the lower end of the discharge unit 5, and the lid 51 holds the filter unit 50.

  The collecting portion 2 of the collecting member 1 is fitted to the reduced diameter portion of the packing follower 35. The upper side of the collecting part 2 is pressed by a packing flange 38. In addition, the lower side of the collecting portion 2 is held at the lower end of the reduced diameter portion of the packing follower 35 by a shoulder portion formed by a portion having a larger diameter than the reduced diameter portion. Thus, the collection member 1 is sandwiched between the packing flange 38 and the packing follower 35.

  Furthermore, in order to seal the fluid from the joining surface of the collection part 2 and the packing follower 35 or the packing flange 38, an O-ring 46 is attached to the lower surface of the packing flange 38 along the collection part 2. A groove is formed, and a groove for circumferentially attaching the O-ring 45 along the collecting portion 2 is formed on the upper surface of the packing follower 35. Since the collection member 1 has a shape that can be sandwiched and fixed between the packing flange 38 and the packing follower 35, the collection member 1 can be attached without changing the basic structure of the general-purpose flow control valve. Become. In FIG. 3, the O-rings 45 and 46 are not shown.

  Next, the rectifying plate 10 installed in the sensor housing 3 will be described with reference to FIGS. 1 and 4. FIG. 4 is an external perspective view showing a rectifying plate installed in the leakage fluid collecting structure of the flow control valve according to Embodiment 1 of the present invention. In FIG. 4, the same or equivalent parts as in FIG. In the following description of the current plate 10, a case where a hydrogen sensor is used as the sensor 20 attached to the sensor housing 3 is taken as an example. It is assumed that the hydrogen sensor includes a spherical surface acoustic wave hydrogen sensor 21 that is a sensing unit, and the spherical surface acoustic wave hydrogen sensor 21 is covered and protected by a metal mesh 22. In this case, hydrogen gas is assumed as the leakage fluid.

  The rectifying plate 10 is connected to the inflow portion 11, one end of which is a hole for allowing the leakage fluid flowing out from the outlet 9 to flow into the sensor accommodating portion 3 on the upper surface of the rectifying plate 10. A plurality of rectifying grooves 12 each being a groove formed to extend are provided. An outflow portion 14 is formed at the center of the rectifying plate 10, and an annular groove 13 is formed on the outer diameter side of the outflow portion 14. The other end opposite to the one end connected to the inflow portion 11 of the rectifying groove 12 is connected to the annular groove 13.

  The leaked fluid introduced from the take-out port 9 flows from the inflow portion 11 of the rectifying plate 10 into the sensor housing portion 3. Then, it flows from the inflow portion 11 through the rectifying groove 12 to the annular groove 13. Since a wall protrudes between the annular groove 13 and the outflow portion 14, the leaked fluid that has entered the annular groove 13 cannot directly go out from the outflow path 14, and the rectifying groove 13 is opposed to the inflow path 11. Flows toward the spherical surface acoustic wave hydrogen sensor 21. The leaked fluid reaches the spherical surface acoustic wave hydrogen sensor 21 through the metal mesh 22 covering the spherical surface acoustic wave hydrogen sensor 21, and then flows downward from the outflow portion 14. By adding the rectifying plate 10 to the leaking fluid collecting structure, there is no possibility that the leaking fluid collected by the collecting member 1 is mixed with external ambient air. Therefore, it is possible to reliably detect leaked fluid using the sensor 20.

  Next, a leakage fluid collecting structure that collects leakage fluid that leaks from around the stem 32 of the flow control valve 30 will be described with reference to FIG. A valve drive unit (not shown) is connected to the stem 32 via the stem adapter 41, and moves the stem 32 up and down or rotates according to the valve opening. When the fluid flowing through the valve body leaks from the gap between the stem 32 and the gland packing 33 due to sliding or rotation of the stem 32, the leakage fluid is the gap between the stem 32 and the packing retainer 34, the stem 32 and the disc spring 37. And the gap between the stem 32 and the seal portion 43 sequentially reach the gap 48 in the packing follower 35. The leaked fluid that has reached the gap 48 flows through the communication hole 36 and flows out to the circumferential groove 6 formed inside the collecting portion 2 of the collecting member 1.

  The leaked fluid that has flowed out to the circumferential groove 6 passes through the flow path 7 as it is, and is introduced from the take-out port 9 into the sensor housing 3. Next, the leaked fluid enters the sensor 20 through the outlet 9 by the rectifying plate 10, and the sensor 20 detects the leak. Thereafter, the leaked fluid is introduced into the discharge portion 5 through the outflow portion 14 of the rectifying plate 10 and the discharge hole 8 of the collecting member 1, passes through the filter portion 50, and is discharged to the outside from the central hole portion of the lid portion 51. Is done.

  As described above, according to the first embodiment, the gland packing 33 that covers the outer peripheral surface of the stem 32 connected to the valve body, the packing follower 35 that inserts the stem 32 and presses the gland packing 33, and the packing follower are fitted. And a leaking fluid collecting structure for a flow rate control valve having a packing flange 38 for fixing the gland packing 33 in a predetermined position. The packing follower 35 has a reduced diameter portion provided at one end and a gap on the outer peripheral side of the stem 32. And the collecting member 1 has a flow path 7 for communicating the communication hole 6 formed in the packing follower 35 and the outlet 9 for taking out fluid to the sensor accommodating portion 3. It was configured as follows. The collection member 1 is fitted into the reduced diameter portion of the packing follower 35 and is sandwiched between the packing flange 38 and the packing follower 35. For this reason, the leakage fluid collection structure of the flow control valve which collects the fluid which leaks from the clearance gap between the stem 32 and the gland packing 33 reliably can be obtained.

  Further, according to the first embodiment, the packing follower 35 has a plurality of communication holes 36, and the collecting member 1 is connected to the plurality of communication holes 36 and provided with the circumferential groove 6 that communicates with the flow path. Therefore, the leaked fluid passing through the communication hole 36 formed in the packing follower 35 can be reliably collected and allowed to flow to the sensor housing 3.

  Furthermore, according to the first embodiment, the sensor 32 that is connected to the take-out port 9 of the collecting member 1 and detects the fluid collected by the collecting member 1 is attached to the sensor housing portion 3, and therefore the stem 32. And the gland packing 33 can directly detect the amount of fluid leaking from the gap.

  In the first embodiment, the collection member 1 includes the collection unit 2, the sensor storage unit 3, the circulation unit 4, and the discharge unit 5, and the sensor 20 is attached to the sensor storage unit 3. The configuration may be such that only the collecting part 2 and the circulation part 4 are provided, and the circulation part 4 and the sensor 20 are directly connected using a tube or the like. In that case, the sensor accommodating part 3, the discharge part 5, and the rectifying plate 10 become unnecessary.

  In the first embodiment, the single flow path 7 is formed at the center of the circulation part 4, but the present invention is not limited to this, and a flow rate necessary for detecting a leaked fluid by the sensor 20 is allowed to flow. What is necessary is just to form so that it may have the volume which can be. When the axial length of the stem 32 including the packing flange 38 is limited, or when it is necessary to shorten the axial length, the collecting member 1 installed therebetween may be thinned. . If the required volume cannot be ensured simply by reducing the thickness of the drawer portion 4 of the collecting member 1 and forming only one channel 7 inside the drawer portion 4, a plurality of channels 7 may be formed.

  In the first embodiment, the O-ring 45 and the O-ring 46 that hold the upper and lower sides of the collecting member 1 on the collecting portion 2 side are respectively mounted in the grooves provided on the upper surface of the packing follower 35 and the lower surface of the packing flange 38. However, a structure may be employed in which grooves are provided on the upper, lower, upper, or lower surfaces of the collecting portion 2 and these O-rings are mounted. In the case of this configuration, it is not necessary to provide an O-ring groove for the leakage collecting structure 1 in the packing follower 35 and the packing flange 38, and it is easy to apply to a flow rate control valve having a general-purpose packing follower and packing flange. Become.

It is sectional drawing which shows the structure of the leakage fluid collection structure of the flow regulating valve which concerns on Embodiment 1 of this invention. It is an external appearance perspective view which shows the leakage fluid collection structure of the flow control valve which concerns on Embodiment 1 of this invention. It is a disassembled perspective view which shows the principal part which comprises the leakage fluid collection structure of the flow regulating valve which concerns on Embodiment 1 of this invention. It is an external appearance perspective view which shows the baffle plate installed in the leakage fluid collection structure of the flow control valve concerning Embodiment 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Collection member 2 Collection part 3 Sensor accommodating part 4 Drawer part 5 Outlet part 6 Outlet part 6 Circumferential groove 7 Flow path 8 Outlet hole 9 Outlet 10 Rectification plate 11 Inflow part 12 Rectification groove 13 Annular groove 14 Outflow part 20 Sensor (leakage detection) Part)
21 spherical surface acoustic wave hydrogen sensor 22 metal mesh 30 flow control valve 31 valve body 32 stem 33 gland packing 34 packing presser 35 packing follower 36 communication hole 37 disc spring 38 packing flange 39 stud bolt 40 nut 41 stem adapters 42, 44, 45, 46, 47 O-ring 43 Sealing part 48 Gap part 50 Filter part 51 Lid part

Claims (3)

A gland packing covering the outer peripheral surface of the stem connected to the valve body;
A packing follower for inserting the stem and holding the gland packing;
A leakage fluid collecting structure for a flow control valve comprising a packing flange for fitting the gland packing to a side opposite to the side on which the gland packing contacts the packing follower,
The packing follower has a reduced diameter portion provided on the side to be fitted with the packing flange, and a communication hole communicating with the stem outer peripheral surface,
And it has a flow passage that communicates the communication hole formed in the packing follower and the outlet to the outside, and provides a collecting member that fits into the reduced diameter portion,
A leakage fluid collecting structure for a flow control valve, wherein the collecting member is sandwiched between the packing flange and the packing follower. The packing follower has a plurality of communication holes,
2. The leakage fluid collecting structure for a flow control valve according to claim 1, wherein the collecting member is connected to the plurality of communication holes and provided with a circumferential groove communicating with the flow path. The leakage fluid collecting structure according to claim 1 or 2,
And the fluid leak detection system provided with the leak detection part connected to the taking-out port which a collection member has, and detecting the fluid which the said collection member collected.

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