Thermally responsive valve

Abstract

To provide a thermally-actuated valve capable of preventing damage to a diaphragm or the like.SOLUTION: When low-temperature drain flows in a direction of an arrow 91, a valve element portion 4 of a movable valve element 10 opens a valve hole 55 so as to discharge the drain in a direction of an arrow 92, and when high-temperature drain or steam flows into a valve chamber 45, the valve element portion 4 of the movable valve element 10 closes the valve hole 55 so as to inhibit outflow of the steam. When the drain flows back due to a back pressure, a spherical valve 2 positioned in a lower communication hole 15b of the valve element portion 4 functions as a check valve, and inhibits the drain mixed with foreign matter from intruding into an intervening space 19.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The technology disclosed herein relates to a thermostatic valve.

Background Art

[0002] As a thermostatic valve, there is a thermostatic steam trap disclosed in Patent Document 1 described later. In the valve chamber 3 of this thermostatic steam trap, a valve seat member 7 having a lead-out passage 8 formed therein is provided, and a temperature control element 9 is disposed above the valve seat member 7.

[0003] The temperature control element 9 has a housing chamber 13 sealed by a first diaphragm 14, and a temperature-sensitive liquid 15 is enclosed in the housing chamber 13. The temperature-sensitive liquid 15 expands in response to a high ambient temperature and contracts in response to a low ambient temperature.

[0004] Further, the temperature control element 9 has a second diaphragm 18 located below the first diaphragm 14, and a valve member 16 is fixed to the second diaphragm 18. The valve member 16 is a valve body that seats and unseats from the valve seat member 7 to open and close the lead-out passage 8. A central hole that communicates the space between the first diaphragm 14 and the second diaphragm 18 and the valve chamber 3 is formed along the vertical direction at the center of the valve member 16.

[0005] When low-temperature condensate flows from the inlet 4 of this thermostatic steam trap into the valve chamber 3, the temperature-sensitive liquid 15 contracts, and the first diaphragm 14 and the second diaphragm 18 are deformed and lifted by the fluid pressure in the valve chamber 3. As a result, the valve member 16 fixed to the second diaphragm 18 unseats from the valve seat member 7 to open the lead-out passage 8. By opening the lead-out passage 8, the condensate is discharged from the outlet 5.

[0006] Thereafter, when high-temperature steam flows into the valve chamber 3, the temperature-sensitive liquid 15 expands, and the valve member 16 seats on the valve seat member 7 through the deformation of the first diaphragm 14 and the second diaphragm 18 to close the lead-out passage 8. This prevents the outflow of steam.

Prior Art Documents

[0007] [Patent Document 1] Japanese Patent Publication No. 2013-151960 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, in the case of the heat-responsive steam trap disclosed in the aforementioned Patent Document 1, if backflow of drain occurs due to back pressure, the backflowing drain may enter the space between the first diaphragm 14 and the second diaphragm 18 through the central hole of the valve member 16.

[0009] The backflowing drain may contain foreign matter such as dust and scale, and if this foreign matter enters the space between the first diaphragm 14 and the second diaphragm 18, the expansion or contraction of the temperature-sensing liquid 15 may cause the first diaphragm 14 and the second diaphragm 18 to deform, potentially leading to damage to these components due to the presence of the foreign matter. In particular, if the first diaphragm 14, which seals the temperature-sensing liquid 15, is damaged, the temperature-sensing liquid 15 will leak out, preventing the temperature control element 9 from functioning properly.

[0010] Therefore, the objective of the thermally responsive valve according to this application is to prevent damage to the diaphragm and other components even when drain water flows back. [Means for solving the problem]

[0011] The thermally responsive valve relating to this application is A main body through which fluid can flow along a channel formed from the inlet to the outlet, A valve seat is provided on the outlet side of the main body, with a valve hole formed through it, A thermally responsive valve comprising a movable valve body provided on the inlet side of the main body, which opens and closes the valve hole by seating with and separating from the valve seat, The movable valve body is A temperature-sensitive medium that expands or contracts in response to temperature, A first diaphragm that deforms in response to the expansion or contraction of the temperature-sensitive medium, A second diaphragm is positioned across space from the first diaphragm and deforms in accordance with the deformation of the first diaphragm, A valve body portion attached to the second diaphragm, which can seat and detach from the valve seat and has a communication hole that connects the space and the flow path, The device is characterized by having a check valve body that closes the communication hole to prevent fluid from flowing into the space when fluid flows backward from the outlet to the inlet. [Effects of the Invention]

[0012] In the thermally responsive valve according to the present invention, the check valve body is movably positioned in the flow path, and when the fluid flows in the opposite direction to the forward direction, it moves in response to the backflow and prevents the fluid from flowing into the communication hole.

[0013] Therefore, it is possible to prevent foreign matter from entering the space formed between the first diaphragm and the second diaphragm through the communication hole. Consequently, damage to the first or second diaphragm, which are composed of diaphragms, can be prevented. [Brief explanation of the drawing]

[0014] [Figure 1] This is a cross-sectional view showing the overall configuration of a thermal responsive valve 1, which represents a first embodiment of the thermal responsive valve according to the present application. [Figure 2] Figure 1 is an enlarged cross-sectional view of the vicinity of the movable valve body 10, showing the state when the valve is open. [Figure 3] Figure 1 is a bottom view of the movable valve body 10. [Figure 4] Figure 1 is an enlarged cross-sectional view of the vicinity of the movable valve body 10, showing the state when the valve is closed. [Figure 5] Figure 1 is an enlarged cross-sectional view of the vicinity of the movable valve body 10, showing the state during backflow. [Mode for Carrying Out the Invention]

[0015] [Term Explanation in Embodiment] The main terms shown in the embodiment respectively correspond to the following elements of the thermal expansion valve according to the present application.

[0016] Sphere valve 2... Check valve body Thermosensitive liquid 9... Temperature-responsive medium Upper communication hole 15a... Communication hole Intervening space 19... Space Casing 40... Main body Inlet 41... Inlet Valve chamber 45 and valve hole 55... Flow path Outlet 42... Outlet Arrows 91, 92... Forward direction Steam or drain... Fluid

[0017] [First Embodiment] The first embodiment of the thermal expansion valve according to the present application will be described by taking the thermal expansion valve as an example. The thermal expansion valve is, for example, provided in a piping system for steam transfer installed in an industrial plant, and is a steam trap that automatically discharges the drain generated from the steam outside the pipe.

[0018] (Explanation of the Overall Configuration of the Thermal Expansion Valve 1) FIG. 1 is a cross-sectional view showing the overall configuration of the thermal expansion valve 1 according to the present embodiment. The casing 40 has a valve chamber 45 inside, and an inlet 41 and an outlet 42 communicating with the valve chamber 45 are formed. The inlet 41 and the outlet 42 each have a substantially cylindrical shape with the axis L1. The inlet 41 is formed above the casing 40 and is connected to, for example, a branch pipe (not shown) of the piping system. The outlet 42 is formed below the casing 40 and is connected to, for example, a discharge pipe (not shown) for drain discharge.

[0019] A substantially cylindrical valve seat 50 is screwed into the casing 40 and fixed at the bottom of the valve chamber 45. A valve hole 55 for draining is formed through the center of the valve seat 50. A movable valve body 10 having a valve body portion 4 is positioned above the valve seat 50. This movable valve body 10 is supported and fixed within the valve chamber 45 by a holder 47. The valve body portion 4 of the movable valve body 10 is positioned close to the upstream end of the valve hole 55 of the valve seat 50. The axes of the valve seat 50 and the movable valve body 10 are aligned with the center line L1.

[0020] The movable valve body 10 expands or contracts in response to ambient temperature, thereby opening and closing the upstream end of the valve port 55. When low-temperature condensate flows into the valve chamber 45 in the direction of arrow 91, the movable valve body 10 can open the upstream end of the valve port 55 to discharge the condensate in the direction of arrow 92. When high-temperature condensate or steam flows into the valve chamber 45, the movable valve body 10 can close the upstream end of the valve port 55 to prevent the condensate or steam from flowing out.

[0021] Figure 2 is an enlarged cross-sectional view of the area including the movable valve body 10, showing the state when the valve is open. The movable valve body 10 is composed of a first case 21 and a second case 22 (see Figure 3), which have a roughly disc shape, and forms an internal space 29 inside. In the internal space 29, a first diaphragm 11 and a second diaphragm 12 are arranged in a double layer in the vertical direction.

[0022] The first diaphragm 11 and the second diaphragm 12 are sandwiched between the first case 21 and the second case 22. The first case 21 and the second case 22 are fixed together by welding their edges together while sandwiching the first diaphragm 11 and the second diaphragm 12.

[0023] The first diaphragm 11 and the second diaphragm 12 are flexible, substantially disc-shaped sheet members, and are not flat plates but rather members with multiple wave-shaped sections formed concentrically. Due to this flexibility and wave-shaped section, the first diaphragm 11 and the second diaphragm 12 can be deformed more significantly in the direction of the central L1 axis, especially in areas closer to the center.

[0024] A sealed liquid chamber 39 is formed between the first diaphragm 11 and the first case 21, and a temperature-sensing liquid 9 is sealed in this liquid chamber 39. This temperature-sensing liquid 9 is composed of water, a liquid with a lower boiling point than water, or a mixture thereof, and when it exceeds a predetermined reference temperature it vaporizes and expands the liquid chamber 39, and when it falls below the reference temperature it liquefies and contracts the liquid chamber 39.

[0025] An injection opening 28 is formed through the center of the first case 21, through which the temperature-sensitive liquid 9 is injected. After the injection of the temperature-sensitive liquid 9, the injection opening 28 is fixed by welding with a stopper 35, sealing the temperature-sensitive liquid 9. The first case 21 is also provided with a stopper 25 that protrudes toward the first diaphragm 11, restricting upward deformation of the first diaphragm 11.

[0026] The second diaphragm 12 forms an intervening space 19 between itself and the first diaphragm 11. A central hole is provided in the center of the second diaphragm 12, and the valve body 4 is mounted in a position including the area around the central hole. A central opening 23 is formed in the center of the second case 22, and the lower surface of the valve body 4 protrudes downward from this central opening 23, with the lower surface of the valve body 4 facing and close to the upstream end of the valve seat 50. The second case 22 also has four peripheral openings 24 that connect the valve chamber 45 (Figure 1) and the internal space 29 (Figure 3).

[0027] A communication hole 15 is formed in the central part of the valve body 4, penetrating in the direction of the center line L1. The communication hole 15 is composed of an upper communication hole 15a located at the top and a lower communication hole 15b located at the bottom. The inner diameter of the upper communication hole 15a is smaller than the inner diameter of the lower communication hole 15b, thereby forming a stepped portion at the connection between the upper communication hole 15a and the lower communication hole 15b.

[0028] Furthermore, the valve body 4 sandwiches the second diaphragm 12 between itself and the contact portion 14 located within the intervening space 19. The valve body 4 and the contact portion 14 are fixed together by welding with the second diaphragm 12 sandwiched between them. The contact portion 14 also has a central hole that penetrates in the direction of the center line L1, and the intervening space 19 and the valve chamber 45 (Figure 1) are in communication through the communication hole 15 of the valve body 4, the central hole of the second diaphragm 12, and the central hole of the contact portion 14.

[0029] As described above, the movable valve body 10 has a double diaphragm structure in which a first diaphragm 11 and a second diaphragm 12 are arranged in superposition. This is to prevent damage to the diaphragm, which deforms repeatedly according to the operation of the movable valve body 10, by providing a first diaphragm 11 for sealing the temperature-sensitive liquid 9 in the liquid chamber 39 and a second diaphragm 12 to which the valve body 4 is fixed separately.

[0030] Furthermore, the double-layered diaphragm structure may make it difficult for the temperature of steam and condensate flowing into the valve chamber 45 to be transmitted to the temperature-sensing liquid 9. For this reason, a communication hole 15 is provided in the valve body 4, a central hole in the second diaphragm 12, and a central hole in the contact portion 14, so that the steam and condensate from the valve chamber 45 can enter the intervening space 19. This makes it easier for the temperature of the steam and condensate that enter the intervening space 19 to be transmitted to the temperature-sensing liquid 9, thereby improving responsiveness.

[0031] In this embodiment, a spherical valve 2, which serves as a check valve, is provided within the lower communication hole 15b of the valve body 4. This spherical valve 2 can be made of, for example, a steel ball. The diameter of the spherical valve 2 is smaller than the inner diameter of the lower communication hole 15b. Also, the length of the lower communication hole 15b in the direction of the centerline L1 is greater than the diameter of the spherical valve 2. Therefore, the spherical valve 2 can float freely within the lower communication hole 15b along the direction of the centerline L1.

[0032] The floating of the spherical valve 2 is restricted by the stepped portion between the upper communication hole 15a and the lower communication hole 15b. When the spherical valve 2 reaches the limit of its floating position, it can close the upper communication hole 15a by coming into contact with the lower end of the upper communication hole 15a.

[0033] As shown in Figure 3, a stopper 5 is fixed to the lower surface of the valve body 4, passing perpendicular to the center line L1 and crossing the lower communication hole 15b. This stopper 5 supports the spherical valve 2 to prevent it from falling out of the lower communication hole 15b.

[0034] (Explanation of the operation of thermally responsive valve 1) Next, the operation of the thermal-responsive valve 1 will be explained. First, immediately after the equipment is started up, the valve chamber 45 of the thermal-responsive valve 1 is filled with air. As a result, the temperature-sensitive liquid 9 sealed in the liquid chamber 39 is contracted due to the influence of the low-temperature air, and the lower surface of the valve body 4 separates from the upper surface of the valve seat 50, opening the valve hole 55, and the thermal-responsive valve 1 is in the open state shown in Figure 2. When steam is supplied to the piping system under pressure in this state, the transfer pressure pushes the air in the valve chamber 45 out of the valve hole 55 to the outlet 42 in the direction of arrow 92 (Figure 1).

[0035] When high-temperature condensate or steam flows into the valve chamber 45 from the inlet 41 in the direction of arrow 91 (Figure 1), the high-temperature condensate or steam passes around the side circumference of the movable valve body 10 and wraps around to the underside of the movable valve body 10. Then, the condensate or steam in the valve chamber 45 enters the internal space 29 through the central opening 23 and the surrounding opening 24 formed in the second case 22.

[0036] Furthermore, high-temperature condensate or steam enters the intervening space 19 through the gap between the lower surface of the valve body 4 and the upper surface of the valve seat 50, passing through the communication hole 15 of the valve body 4, the central hole of the second diaphragm 12, and the central hole of the contact portion 14. At this time, the spherical valve 2 located in the lower communication hole 15b of the valve body 4 remains in contact with the stopper 5 due to its own weight. As high-temperature condensate or steam passes around the movable valve body 10, and as high-temperature condensate or steam enters the internal space 29 and the intervening space 19, the temperature-sensitive liquid 9 sealed in the liquid chamber 39 expands in response to the temperature of the condensate or steam.

[0037] When the temperature-sensitive liquid 9 expands, the central part of the first diaphragm 11 deforms so that it extends downward along the center line L1. This state is shown in Figure 4. The deformed first diaphragm 11 presses the upper surface of the contact portion 14 with its lower surface, pushing down the second diaphragm 12. As a result, the deformation of the first diaphragm 11 is transmitted to the second diaphragm 12, the lower surface of the valve body 4 comes into contact with the upper surface of the valve seat 50, the valve body 4 seats on the valve seat 50, and the thermal-responsive valve 1 closes. The closing of the thermal-responsive valve 1 prevents steam leakage from the thermal-responsive valve 1.

[0038] Next, if steam condenses within the piping system and generates condensate, the low-temperature condensate flows from the inlet 41 into the valve chamber 45 of the thermal-responsive valve 1 in the direction of arrow 91, and enters the internal space 29 and the intervening space 19. As a result, the temperature-sensitive liquid 9 sealed in the liquid chamber 39 contracts in response to the low temperature of the condensate.

[0039] In response to this contraction, the first diaphragm 11 deforms upward along the center line L1 due to its own restoring force and the fluid pressure in the valve chamber 45, returning to the state shown in Figure 2. The upward deformation of the first diaphragm 11 is restricted by the stopper 25, and the position where it contacts the stopper 25 is the limit of the upward deformation of the first diaphragm 11.

[0040] Following the deformation of the first diaphragm 11 upward and its subsequent return to its original position, the second diaphragm 12 similarly deforms upward due to its own restoring force and the fluid pressure within the valve chamber 45. As a result, the lower surface of the valve body 4 separates from the upstream end of the valve seat 50, and the thermally responsive valve 1 opens.

[0041] When the thermal-responsive valve 1 opens, the drain is automatically discharged through the valve hole 55 of the valve seat 50 and the outlet 42 in the direction of arrow 92 (Figure 1) due to the force of the high pressure in the piping. After the drain has been discharged, when high-temperature drain or steam flows back into the valve chamber 45, the temperature-sensitive liquid 9 expands, and as shown in Figure 4, the valve body 4 seats on the upstream end of the valve seat 50, causing the thermal-responsive valve 1 to close.

[0042] Incidentally, in the thermally responsive valve 1, drain may flow back from the discharge pipe through the outlet 42 due to back pressure. The backflowing drain may contain foreign matter such as dust and scale, and if such foreign matter enters the intervening space 19 formed between the first diaphragm 11 and the second diaphragm 12, the first diaphragm 11 and the second diaphragm 12 may be damaged by the presence of the foreign matter when the first diaphragm 11 and the second diaphragm 12 deform.

[0043] In this embodiment, the spherical valve 2 located in the lower communication hole 15b of the valve body 4 functions as a check valve, preventing drain from entering the intervening space 19. That is, as shown in Figure 5, the spherical valve 2 floats up due to the force of back pressure and the backflow of drain in the direction of arrow 93. It then abuts against the stepped portion formed at the connection between the upper communication hole 15a and the lower communication hole 15b of the valve body 4, and contacts the upper communication hole 15a from below, closing the upper communication hole 15a.

[0044] This prevents foreign matter from entering the intervening space 19 and prevents damage to the first diaphragm 11 and the second diaphragm 12. When the backflow of drain in the direction of arrow 93 stops, the spherical valve 2 descends by its own weight and returns to a state that opens the upper communication hole 15a.

[0045] [Other embodiments] In the embodiments described above, the thermally responsive valve 1 was exemplified as a thermally responsive valve, but the thermally responsive valve according to the present invention can be applied to other automatic valves as long as they open and close the valve holes of the valve seat according to the temperature of the incoming fluid.

[0046] Furthermore, in the above-described embodiment, the first diaphragm 11 was exemplified as the first diaphragm and the second diaphragm 12 as the second diaphragm, but other shapes and structures can be used as long as they are configured to deform in response to the expansion or contraction of the temperature-sensitive liquid 9, etc.

[0047] Furthermore, in the embodiments described above, the thermosensitive liquid 9 was exemplified as water, a liquid with a lower boiling point than water, or a mixture thereof. However, other liquids or non-liquid materials can be used as long as they expand or contract in response to ambient temperature.

[0048] Furthermore, although the above-described embodiment exemplified a spherical valve 2 composed of steel balls as the check valve body, other shapes and structures can be used as long as they come into contact with the communication hole 15, etc., and prevent the fluid (steam or drain, etc.) from flowing back into the intervening space 19, etc. For example, a hollow spherical body can be used, and a disc-shaped member can also be used instead of a spherical one. [Explanation of Symbols]

[0049] 1: Heat-sensitive valve 2: Spherical valve 4: Valve body 9: Temperature-sensitive liquid 10: Movable valve body 11: First diaphragm 12: Second diaphragm 15: Communication hole 19: Intervening space 40: Casing 41: Inlet 42: Outlet 45: Valve chamber 55: Valve opening

Claims

1. A main body through which fluid can flow along a channel formed from the inlet to the outlet, A valve seat is provided on the outlet side of the main body, with a valve hole formed through it, A thermally responsive valve comprising a movable valve body provided on the inlet side of the main body, which opens and closes the valve hole by seating with and separating from the valve seat, The movable valve body is A temperature-sensitive medium that expands or contracts in response to temperature, A first diaphragm that deforms in response to the expansion or contraction of the temperature-sensitive medium, A second diaphragm is positioned with respect to the first diaphragm, with space between them, and deforms in accordance with the deformation of the first diaphragm. A valve body portion is attached to the second diaphragm, can seat and detach from the valve seat, and has a communication hole that connects the space and the flow path, A thermally responsive valve having a check valve body that closes the communication hole to prevent fluid from flowing into the space when fluid flows backward from the outlet to the inlet.

2. In the thermally responsive valve according to claim 1, The aforementioned check valve body is a spherical valve, a thermally responsive valve.

Images