Automatic valve system

Abstract

To provide an automatic valve system which can reliably determine both a valve-opening leaving state of a bypass valve and a liquid leak state of an automatic valve while having a simple structure.SOLUTION: A branch pipe 11 having a steam trap 3 is provided with a bypass pipe 12. A bypass valve 4 is attached to the bypass pipe 12. A connecting pipe 13 connecting the branch pipe 11 and the bypass pipe 12 is also provided, and sight glass 2 having an oscillation ball 28 arranged in a glass pipe 25 is arranged in the connecting pipe 13. When there is a valve-opening leaving state such as due to omission to close the bypass valve 4, the oscillation ball 28 moves to the bypass pipe 12 side to indicate the valve-opening leaving state. Also, when steam leakage occurs at the steam trap 3, the oscillation ball 28 moves to the branch pipe 11 side due to a pressure difference in piping to indicate steam leakage.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The automatic valve system according to the present application relates to a technology of the configuration of an automatic valve system in which a bypass pipe and a bypass valve are provided for an automatic valve.

Background Art

[0002] As an automatic valve system in which a bypass pipe and a bypass valve are provided for an automatic valve, there is an automatic valve system using a steam trap or a drain trap. This steam trap or drain trap is installed in a branch pipe of a steam piping system and discharges drain (condensate) generated by heat exchange of steam to the outside of the pipe. And a bypass pipe having a bypass valve is connected to the branch pipe where the steam trap or the drain trap is provided, and backup and assistance of the steam trap or the drain trap are performed.

[0003] As such an automatic valve system, there is a drain trap system disclosed in Patent Document 1 described below. In this system, an inlet valve 3, a strainer 4, a drain trap 5, and an outlet valve 6 are sequentially provided in a drain pipe 2 branched and connected from a steam pipe 1. And a bypass pipe 8 having a bypass valve 9 is connected to the drain pipe 2 on the inlet side of the inlet valve 3 and the outlet side of the outlet valve 6.

[0004] Further, a surface thermometer 10 is provided on the surface of the drain trap 5, and the surface thermometer 10 is connected to a recorder 12 through a signal cable 11. And the recorder 12 is further connected to an alarm generation circuit 13, and an alarm from this alarm generation circuit 13 is displayed in a central operation room 14. Thereby, the operation and inoperation of the drain trap 5 are monitored.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the system disclosed in the above Patent Document 1, there are the following problems. First, the bypass valve 9 provided in the bypass pipe 8 may be left open due to oversight or the like. When such an open-valve state occurs, steam continues to flow out from the bypass pipe 8, resulting in a problem of loss due to steam loss.

[0007] In particular, for the bypass valve 9, a ball valve that moves the valve body in the vertical direction is often used to enhance the certainty of opening and closing, and since a rotary round handle is attached, it is difficult to visually check the open-valve state of the bypass valve 9. For this reason, it is necessary for the operator to rotate the round handle each time to check whether the bypass valve 9 is properly closed, resulting in a decrease in work efficiency.

[0008] Next, in the system disclosed in the above Patent Document 1, it is necessary to install devices such as a surface thermometer 10, a recorder 12, and an alarm generation circuit 13 to detect malfunction of the drain trap 5, resulting in a problem of system complexity.

[0009] In steam traps and drain traps, a malfunction of steam leakage may occur where steam leaks despite being in a closed-valve state. In such a case, a loss due to steam loss is incurred. To detect a malfunction of steam leakage, for example, it is necessary to attach a vibration detector that detects leakage sound to the steam trap or drain trap and provide a circuit that processes the vibration signal, similarly resulting in system complexity.

[0010] Therefore, the automatic valve system according to the present application aims to provide an automatic valve system that can reliably grasp both the open-valve state of the bypass valve and the fluid (such as steam) leakage state in automatic valves such as steam traps and drain traps, while having a simple configuration to solve these problems.

Means for Solving the Problems

[0011] The automatic valve system according to the present application is a basic flow path through which fluid passes inside, an automatic valve provided in the basic flow path for blocking or allowing the passage of the fluid from the inlet side to the outlet side, which is normally in a closed valve state to block the passage of the fluid and automatically opens in an open valve state during operation to allow the passage of the fluid, a bypass path connecting the basic flow path on the inlet side of the automatic valve and the basic flow path on the outlet side of the automatic valve, a bypass on-off valve provided in the bypass path for blocking or allowing the passage of the fluid from the inlet side to the outlet side, which blocks the passage of the fluid when in the closed valve state and allows the passage of the fluid when in the open valve state, pressure difference display means for displaying corresponding to the pressure difference between the basic flow path on the inlet side of the automatic valve and the bypass path on the inlet side of the bypass on-off valve, and is characterized by comprising the above.

Advantages of the Invention

[0012] In the automatic valve system according to the present application, the pressure difference display means displays corresponding to the pressure difference between the basic flow path on the inlet side of the automatic valve and the bypass path on the inlet side of the bypass on-off valve.

[0013] For example, when an open valve left state occurs where the bypass valve is left open, a pressure difference is generated due to the pressure in the bypass path being lower than the pressure in the basic flow path, and the pressure difference display means displays corresponding to this pressure difference. Therefore, it is possible to surely grasp the open valve left state of the bypass valve with a simple configuration.

[0014] Also, when a fluid leakage state of the automatic valve occurs while the bypass valve is closed, a pressure difference is generated due to the pressure in the bypass path being higher than the pressure in the basic flow path, and the pressure difference display means displays corresponding to this pressure difference. Therefore, it is possible to surely grasp the fluid leakage state of the automatic valve of the bypass valve with a simple configuration.

[0015] As described above, in the automatic valve system according to the present application, although it has a simple configuration, it is possible to surely grasp both the open state of the bypass valve left open and the fluid leakage state in the automatic valve.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0017] [Term Explanation in the Embodiment] The main terms shown in the embodiment respectively correspond to the following elements of the automatic valve system according to the present application.

[0018] Sight glass 2... Pressure difference display means Steam trap 3... Automatic valve Bypass valve 4... Bypass on-off valve Branch pipe 11... Basic flow path Bypass pipe 12... Bypass path Connection pipe 13... Detection connection path Glass pipe 25... Display part, cylindrical body Swinging ball 28... Moving body Drain or air, etc... Fluid

[0019] [First Embodiment] A first embodiment of the automatic valve system according to the present application will be described with reference to the drawings. In this embodiment, an automatic valve system including a steam trap, which is a type of self-acting automatic valve, will be exemplified.

[0020] (Overall configuration of the system) FIG. 1 is a configuration diagram of a piping system for steam transfer installed in an industrial plant or the like. The main pipe 10 transfers high-temperature and high-pressure steam from the upstream to the downstream. Drain is generated in the main pipe 10 due to heat exchange of the transferred steam. To discharge this drain, branch pipes 11 are connected to the main pipe 10 at various locations, and steam traps 3 are provided in each branch pipe 11. Note that, following the flow of steam in the branch pipe 11, the upstream side (primary side) is the inlet side and the downstream side (secondary side) is the outlet side when viewed from the steam trap 3.

[0021] An inlet valve 41 is provided in the branch pipe 11 on the upstream side of the steam trap 3, and an outlet valve 42 is provided in the branch pipe 11 on the downstream side of the steam trap 3. The inlet valve 41 and the outlet valve 42 are configured by, for example, ball valves and are provided with lever-type handles.

[0022] The steam trap 3 is an automatic valve that appropriately discharges drain to the outside of the pipe and operates so as to minimize steam leakage. There are various structures for steam traps, but the float-type steam trap has a hollow float built into the valve chamber. And, normally, this float closes the drain outlet formed near the bottom of the valve chamber (closed valve state) and blocks the passage of drain through the valve chamber. On the other hand, when drain flows into the valve chamber, this float floats up during operation following the retention of the drain (open valve state), and automatically opens the drain outlet to open the valve.

[0023] When the drain outlet is opened, the passage of the drain through the valve chamber is allowed, and the drain remaining in the valve chamber is automatically discharged from the drain outlet under the influence of the high pressure in the pipe. After the drain is discharged, the float descends and resets, closing the drain outlet again. Note that although the float repeatedly rises and falls to discharge the drain in this way, since the drain outlet is always submerged in the drain, no steam leakage occurs from the steam trap 3 during normal operation.

[0024] Here, a bypass pipe 12 connecting the upstream side of the inlet valve 41 and the downstream side of the outlet valve 42 is provided in the branch pipe 11, and a bypass valve 4 is attached to this bypass pipe 12. This bypass valve 4 is composed of, for example, a ball valve that moves the valve body in the vertical direction and is equipped with a round handle. Note that following the flow of steam in the bypass pipe 12, the upstream side (primary side) is the inlet side and the downstream side (secondary side) is the outlet side when viewed from the bypass valve 4.

[0025] The bypass valve 4 provides backup and assistance for the steam trap 3 provided on the branch pipe 11. That is, when it becomes necessary to replace the steam trap 3 due to equipment failure or the like, first open the bypass valve 4 to allow steam or the like to pass through the bypass pipe 12. Then, close the inlet valve 41 and the outlet valve 42 sequentially to interrupt the flow of steam or the like in the branch pipe 11, and then replace the steam trap 3. After that, as a restoration operation, open the outlet valve 42 and the inlet valve 41 sequentially, and then close the bypass valve 4 to block the passage of steam in the bypass pipe 12.

[0026] Also, at the start-up of the piping system, the pipe is filled with initial air, and in order to eliminate air binding (air obstruction) caused by this initial air, it is necessary to exhaust the initial air outside the pipe. In such a case, by fully opening the bypass valve 4, rapid exhaust is performed through the bypass pipe 12. Furthermore, in order to supplement the drain discharge function of the steam trap 3, the opening degree of the bypass valve 3 may be adjusted to constantly discharge a small amount of drain through the bypass pipe 12.

[0027] By the way, in the present embodiment, a connecting pipe 13 is provided to connect a branch pipe 11 on the upstream side of the inlet valve 41 and a bypass pipe 12 on the upstream side of the bypass valve 4. And a sight glass 2 is installed in this connecting pipe 13.

[0028] FIG. 2 is an enlarged plan view of the sight glass 2. The sight glass 2 has bases 21a and 21b supported by a plurality of columns 23, and these bases 21a and 21b are fixed to the connecting pipe 13 respectively. Display labels 22a and 22b are respectively attached to the bases 21a and 21b.

[0029] A transparent glass tube 25 is provided between the bases 21a and 21b. Through holes are formed in the central portions of the bases 21a and 21b, so that the glass tube 25 communicates with the connecting pipe 13. Note that the inner diameter of the glass tube 25 is formed to be sufficiently larger than the inner diameter of the connecting pipe 13.

[0030] A swing ball 28 is arranged in the glass tube 25. This swing ball 28 is formed in a spherical shape with, for example, fluororesin, and the diameter of the swing ball 28 is substantially the same as the inner diameter of the glass tube 25. And the swing ball 28 is arranged in the glass tube 25 in a state where it can swing in the directions of arrows 91 and 92 along the central axis of the glass tube 25.

[0031] FIG. 2 shows the normal state of the sight glass 2 in normal times. In normal times, although the steam trap 3 repeats draining, no steam leakage occurs, so steam is not discharged from the outlet side of the steam trap 3. Also, in normal times, since the bypass valve 4 is in a closed state, steam is not discharged from the outlet side of the bypass valve 4.

[0032] Therefore, there is no pressure difference between the pressure in the connecting pipe 13 on the branch pipe 11 side sandwiching the sight glass 2 and the pressure in the connecting pipe 13 on the bypass pipe 12 side sandwiching the sight glass 2. For this reason, the swing ball 28 of the sight glass 2 is located at the center of the glass tube 25 while maintaining balance.

[0033] For this reason, by visually observing that the swing ball 28 of the sight glass 2 is located at the center of the glass tube 25, the operator can easily and surely recognize that the bypass valve 4 is properly closed and there is no steam leakage from the steam trap 3.

[0034] (Operation of the sight glass 2 in the state where the bypass valve 4 is left open) The bypass valve 4 may be left open due to being forgotten to be closed, etc. The operation of the sight glass 2 in such a state where it is left open will be described based on FIG. 3.

[0035] When the bypass valve 4 is left open, since steam continues to pass through and flow out of the bypass pipe 12, the static pressure in the bypass pipe 12 decreases by the amount of its dynamic pressure. On the other hand, since the steam trap 3 is configured such that no steam leakage occurs during normal operation, the static pressure in the branch pipe 11 is maintained at a high pressure.

[0036] As a result, a pressure difference occurs based on the fact that the pressure in the connecting pipe 13 on the bypass pipe 12 side sandwiching the sight glass 2 is lower than the pressure in the connecting pipe 13 on the branch pipe 11 side sandwiching the sight glass 2. According to this pressure difference, the swing ball 28 moves inside the glass tube 25 toward the bypass pipe 12 side (moves in the direction of arrow 91) and reaches the limit position on the base 21a side. FIG. 3 shows this state.

[0037] For this reason, by visually observing that the swing ball 28 of the sight glass 2 is located on the limit position side on the base 21a side inside the glass tube 25, the operator can easily and surely recognize that the bypass valve 4 is in a state of being left open due to being forgotten to be closed, etc.

[0038] In addition, in the present embodiment, a display label 22a marked with "Bypass Valve Open and Left" is attached to the base 21a. Therefore, the operator can more surely recognize the open and left state of the bypass valve 4.

[0039] (Operation of the sight glass 2 in the steam leakage state of the steam trap 3) Steam leakage malfunctions may occur in the steam trap 3 where steam leaks despite being in the closed valve state. The operation of the sight glass 2 in such a steam leakage state will be described with reference to FIG. 4.

[0040] When steam leakage occurs in the steam trap 3, since steam passes through and leaks from the branch pipe 11, the static pressure in the branch pipe 11 decreases by the amount of the dynamic pressure. On the other hand, since the bypass valve 4 is normally closed, the static pressure in the bypass pipe 12 is maintained at a high pressure.

[0041] As a result, a pressure difference occurs based on the fact that the pressure in the connecting pipe 13 on the bypass pipe 12 side across the sight glass 2 is higher than the pressure in the connecting pipe 13 on the branch pipe 11 side across the sight glass 2. According to this pressure difference, the swing ball 28 moves inside the glass tube 25 toward the branch pipe 11 side (moves in the direction of arrow 92) and reaches the limit position on the base 21b side. FIG. 4 shows this state.

[0042] Therefore, by visually observing that the swing ball 28 of the sight glass 2 is located at the limit position on the base 21b side inside the glass tube 25, the operator can easily and surely recognize that steam leakage has occurred in the steam trap 3.

[0043] In addition, in the present embodiment, a display label 22b marked with "Steam Leakage of Steam Trap" is attached to the base 21b. Therefore, the operator can more surely recognize the steam leakage of the steam trap.

[0044] [Other Embodiments] In the foregoing embodiments, an automatic valve system equipped with a steam trap was exemplified as the automatic valve system. However, the present invention is not limited thereto, and the automatic valve system according to the present application can be applied to a system equipped with other self-acting automatic valves.

[0045] Further, as the pressure difference display means, as long as it performs a display corresponding to the pressure difference between the basic flow path (such as the branch pipe 11) on the inlet side of the automatic valve (such as the steam trap 3) and the bypass path (such as the bypass pipe 12) on the inlet side of the bypass on-off valve (such as the bypass valve 4), other configurations may be adopted.

[0046] Furthermore, in the foregoing embodiments, the sight glass 2 in which the swing ball 28 is movably arranged in the glass tube 25 was exemplified as the pressure difference display means. However, the present invention is not limited thereto, and other shapes and structures may be adopted. For example, although the glass tube 25 provided in the sight glass 2 was exemplified, a transparent window portion may be formed in a part of the non-transparent cylindrical body, and a moving body (such as the swing ball 28) may be arranged so as to be visible from the outside through this window portion.

[0047] In addition, although the spherical swing ball 28 was exemplified as the moving body, as long as it moves according to the pressure difference between the basic flow path (such as the branch pipe 11) on the inlet side of the automatic valve and the bypass path (such as the bypass pipe 12) on the inlet side of the bypass on-off valve (such as the bypass valve 4), other shapes and structures can be adopted. For example, the moving body can be configured in a disk shape or other shapes other than the spherical shape.

Explanation of Reference Numerals

[0048] 2: Sight glass 3: Steam trap 4: Bypass valve 11: Branch pipe 12: Bypass pipe 13: Connecting pipe 25: Glass tube 28: Swing ball

Claims

1. A basic flow path through which a fluid passes inside; An automatic valve provided in the basic flow path, which shuts off or allows the passage of the fluid from the inlet side to the outlet side. The automatic valve is normally in a closed state to shut off the passage of the fluid and automatically opens during operation to allow the passage of the fluid; A bypass path connecting the basic flow path on the inlet side of the automatic valve and the basic flow path on the outlet side of the automatic valve; A bypass on-off valve provided in the bypass path, which shuts off or allows the passage of the fluid from the inlet side to the outlet side. The bypass on-off valve shuts off the passage of the fluid when in the closed state and allows the passage of the fluid when in the open state; Pressure difference display means for performing a display corresponding to the pressure difference between the basic flow path on the inlet side of the automatic valve and the bypass path on the inlet side of the bypass on-off valve; An automatic valve system characterized by comprising the above.

2. In the automatic valve system according to Claim 1, It includes a detection connection path connecting the basic flow path on the inlet side of the automatic valve and the bypass path on the inlet side of the bypass on-off valve, The pressure difference display means is provided in the detection connection path. An automatic valve system characterized by the above.

3. In the automatic valve system according to Claim 2, The pressure difference display means is a cylindrical body having a display portion and a moving body movably incorporated in the cylindrical body and moving according to the pressure difference, The movement of the moving body is displayed through the display portion. An automatic valve system characterized by the above.

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