JP2002295720A - Shut-off valve unit - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To obtain a shut-off valve unit capable of shutting off a flow path by itself and requiring no system construction. SOLUTION: A shutoff valve which is installed in a housing and is provided with an urging force for holding the valve body 22 in a closed position to open and close a flow path, and a locking member 19 for locking the valve body 22 of the shutoff valve. Constitute. The locking member 19 includes a locking portion 24 that is displaceably provided between a locking position for locking the valve body 22 at the open position and a lock release position for releasing locking of the valve body 22 at the open position.
The first spring member 29 made of a shape memory alloy whose elasticity is lost in the low temperature range while the lock portion 24 is held in the locking position by the elastic force in the normal temperature range, and the first spring member 29 in the normal temperature range. A second spring member 30 is provided which allows the spring force of the spring member 29 and displaces the lock portion 24 to the unlocked position by the elastic force due to the loss of the elastic force of the first spring member 29 in a low temperature range. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shut-off valve unit, and more particularly to a shut-off valve unit that closes a flow passage by inflow of a fluid having a predetermined temperature.

[0002]

2. Description of the Related Art For example, equipment for handling a specific fluid such as LNG (liquefied natural gas), which is a dangerous fluid, has a problem that the fluid may flow through a rainwater pan installed under a pipe or a tank, etc. to the outside. A shut-off valve unit is provided so that even if it leaks from a pipe or the like, it does not flow outside.

[0003] The shut-off valve unit is a sensor for detecting fluid leakage (for example, a temperature sensor or a gas detector).
A shut-off valve that opens and closes the flow path with the power source, and a control unit that operates the power source in response to fluid leakage detection information from the sensor to set the shut-off valve to the closed position.

Therefore, in order to operate such a shut-off valve unit, an instrumentation and a system had to be assembled.

[0005]

In such a conventional shut-off valve unit, since a system must be constructed, not only is the apparatus expensive, but also complicated installation work is required. In addition, since the system must be constructed in this way, the apparatus becomes complicated and the maintenance cost is increased.

Accordingly, an object of the present invention is to provide a shut-off valve unit that does not require system construction.

[0007]

To solve the above-mentioned problems, a shut-off valve unit according to the present invention is provided with a housing and a flow passage provided in the housing and provided with an urging force for holding the valve body in a closed position. A shut-off valve for opening and closing the valve, and a lock portion at a locking position for locking the valve body at the open position in the first temperature range, and locking the valve body at the open position in the second temperature range. A locking member provided with a shape memory alloy that allows the lock portion to be displaced to a lock releasing position for releasing, and locking when the temperature changes from the first temperature range to the second temperature range. The lock portion holding the valve body at the position is displaced to the unlocked position, and the valve body is brought to the closed position by the urging force.

Further, the shut-off valve unit according to the present invention is provided with a housing, a shut-off valve installed in the housing, for applying a biasing force for holding the valve body in a closed position to open and close a flow path, and opening the valve body. A lock portion displaceably provided between a lock position for locking at the position and a lock release position for releasing the lock at the open position of the valve body. The lock portion is resiliently provided in the first temperature range. The first spring member made of a shape memory alloy that loses the resilience in the second temperature range and is held in the locking position and reduces the resilience of the first spring member in the first temperature range. A locking member made of a second spring member that allows the lock portion to be displaced to the unlocked position by a resilient force due to a loss of resilience of the first spring member in the second temperature range, Locked when the temperature changes from the first temperature range to the second temperature range Wherein the locking portion holding the valve body location is to the valve body is displaced to the unlocked position is the closed position by the biasing force.

According to the invention, since the locking member itself can detect the temperature and shut off the flow path without using a power source or a heat sensing system, it is not necessary to construct a system. Become.

[0010]

Embodiments of the present invention will be described below more specifically with reference to the drawings. Here, the same reference numerals are given to the same members in the attached drawings,
In addition, duplicate description is omitted. The embodiments of the present invention are particularly useful forms in which the present invention is implemented, and the present invention is not limited to the embodiments.

FIG. 1 is a schematic view showing a plant in which a shut-off valve unit according to an embodiment of the present invention is used, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing a shut-off valve unit according to an embodiment, FIG. 4 is a perspective view showing a locking member in the shut-off valve unit in FIG. 3, and FIG. 5 shows the locking member in FIG. 4 held in a locking position. FIG. 6 is an explanatory view showing the locking member of FIG. 4 held at the unlocking position.

As shown in FIG. 1, a shut-off valve unit 11 according to the present embodiment is installed in a plant 12 that handles, for example, LNG (fluid) that is a low-temperature fluid.

Here, two facilities 13 for handling LNG
Are connected by a pipe 14 through which LNG flows. A rainwater pan 15 is installed under the pipe 14,
As shown in detail in FIG. 2, a drain pipe 16 for discharging the rain water that has flowed down is connected to the rain water pan 15. The drain pipe 16 has the shut-off valve unit 1
1 is installed.

The shut-off valve unit 11 prevents LNG from flowing out of the drain pipe 16 to the outside even if LNG leaks from the pipe 14. Therefore, the shut-off valve unit 11 is in the open position when a normal temperature fluid such as rainwater flows, and is in the closed position when a low temperature fluid such as LNG flows.

As shown in FIG. 3, the shut-off valve unit 11
Includes a housing 17, a shutoff valve 18 installed in the housing, and a locking member 19 for locking the shutoff valve 18.

The shutoff valve 18 comprises an arm 21 swingably fixed to the housing 17 by a hinge pin 20, and a valve body 22 attached to the arm 21 to open and close a flow path. The shut-off valve 18 is installed and used in a vertical direction so that it is in an open position when the valve body 22 is raised and is substantially horizontal and in close contact with the valve seat 23 to be in a closed position. Then, by such vertical installation, the valve body 22 is provided with an urging force that is held at the closed position by its own weight.

Here, in the present specification, the urging force does not mean only the one utilizing the elastic force of an elastic member such as a spring, but also the self-weight effect utilizing gravity as shown in the present embodiment. Things are also included. When the urging force is applied to the valve body 22 by the elastic member, the valve body 22 can be used not only in the vertical direction but also in a direction other than the vertical direction such as a horizontal direction.

A check valve such as a swing check, a ball check, a wafer check, and a lift check is used as the shut-off valve 18, and the shut-off valve 18 can be applied by applying a biasing force held at a closed position to the valve body. It is possible. Therefore, the valve body is not a valve body 22 that swings by a swing fulcrum as shown in the present embodiment, but, for example, a spherical valve body rotatably disposed on a flow path, or in the axial direction of the flow path. A valve body or the like which is displaceable can be used. That is, various types of shut-off valves can be used as long as an urging force for holding the valve body at the closed position is given.

A locking member 19 for locking the shut-off valve 18
As shown in FIG. 4, the frame 26 has a base 26a fixed to the fixing portion 17a of the housing 17 and a mounting portion 26b opposed to the base 26a. The mounting portion 26b is attached to the mounting portion 26b.
A shaft 25 is attached so as to be able to reciprocate so as to protrude and retract from the shaft. An O-ring is incorporated in the shaft 25 to prevent freezing of the shaft 25 to ensure the operation.

At the protruding end of the shaft 25,
A lock portion 24 is provided that can be displaced between a locking position for locking the valve body 22 at the open position and a lock release position for releasing such locking of the valve body 22 at the open position. In the present embodiment, the lock portion 24 and the shaft 25 are separate bodies, but they may be integrally configured,
The valve body 22 may be locked by itself, and the shaft 25 may have a function as the lock portion 24. In this case, the shaft 25 becomes the lock portion 24 as it is.

A cup-shaped piston 27 is mounted coaxially with the shaft 25 at an end of the shaft 25 opposite to the lock portion 24. The piston 27 has a circular opening on the side opposite to the shaft 25, that is, the upper part, and a flange 28 (FIGS. 5 and 6) is formed on the outer peripheral edge thereof. Then, the opening of the piston 27 is communicated to be substantially the same diameter as the circular opening 26a ₁ formed in the base portion 26a of the frame 26, it is arranged so as to be coaxial with each other. Note that the fixing portion 17a of the housing 17, the opening that opens upwardly in communication with the opening 26a ₁ of the base portion 26a (not shown) is formed.

A first spring member 29 is provided in the piston 27.
However, a second spring member 30 is mounted on the outer periphery of the piston 27.

The first spring member 29 is inserted into the piston 27 from the opening of the base 26a, and presses the piston 27 toward the locking position of the lock portion 24. Therefore,
When the frame 26 is fixed to the fixing portion 17a on the housing 17 side, the first spring member 29 comes into contact with the fixing surface, so that the first spring member 29 causes the lock portion 24 to protrude by its elastic force. This is held in the locked position.

Here, the first spring member 29 has an elastic force in a normal temperature range (first temperature range).
In a low temperature range of 40 ° C. or lower (second temperature range), the elastic body is formed of a shape memory alloy that loses elasticity. Therefore, when the temperature is lower than −40 ° C., the lock portion 24 cannot be positively held at the locking position.

The pitch when the first spring member 29 contracts is set to be 4 mm or more. This prevents malfunctions when water droplets attached to the first spring member 29 freeze.

The second spring member 30 is mounted between the flange 28 of the piston 27 and the mounting portion 26b of the frame 26, and moves the piston 27 in the unlocking position of the lock portion 24 in the direction opposite to the locking position. Is pressed. The resilient force is weaker than the resilient force of the first spring member 29 in the normal temperature range, and locks the lock portion 24 at −40 ° C. or less where the resilient force of the first spring member 29 is lost. It is set to such an extent that it can be displaced to the release position. Therefore, in the normal temperature range, the second spring member 30 allows the resilient force of the first spring member 29 to hold the lock portion 24 in the locking position. The locking portion 24 is retracted to the unlocked position by the resilient force.

[0027] Although by generating first spring member 29 resiliently force by utilizing the fixing portion 17a of the housing 17 side in the present embodiment, the first spring to the opening 26a ₁ of the base portion 26a A member that presses the member 29 may be attached, and the member may generate an elastic force.

A cover 31 is attached to such a locking member 19 to prevent intrusion of solids.
A plurality of holes 31a are formed in the cover 31 as a whole, so that the fluid that has flowed into the inside smoothly escapes to the outside, thereby preventing a malfunction from occurring.

In this embodiment, the diameter of the hole 31a is equal to 0.
It is 8 mm, and the operating speed of the lock portion 24 is improved by making the frozen water into a bearing shape.

As shown in FIG. 3, a detachable lid 32 is provided in the housing 17 on the side of the shut-off valve 18. By removing the lid 32 and locking the valve body 22 in the closed position to the lock portion 24, the valve body 22 can be easily returned to the open position. Although the lid 32 of the present embodiment is detachable,
It may be openable and closable using a hinge mechanism or the like.

Next, the operation of the locking member 19 in the shut-off valve unit 11 having such a configuration will be described with reference to FIGS.

When fluid in a normal temperature range, such as rainwater, flows through the shut-off valve unit 11, the elastic force of the first spring member 29 is greater than the elastic force of the second spring member 30. I'm winning. Therefore, as shown in FIG. 5, the lock portion 24 is protruded by the elastic force of the first spring member 29 and is held at the locking position. Therefore, the valve element 22 is locked at the open position by the lock portion 24 at the locked position.

In such a state, for example, the pipe 1
When LNG, which is a low-temperature fluid leaked from the tank 4, flows into the shut-off valve unit 11 from the rainwater pan 15 through the drain pipe 16, a part of the LNG is fixed to the fixing portion 17 a of the housing 17.
From the opening formed in the opening 26a _{1 of the} base 26a.
Through the cup-shaped piston 27.

The first spring member 29 in the piston 27
When the temperature is 40 ° C. or lower, the elastic material is formed of a shape memory alloy that loses elasticity. Then, as shown in FIG.
Due to the resilient force of the spring member 30, the piston 27 moves in the direction to contract the first spring member 29, and accordingly, the lock portion 24 is displaced to the unlocked position.

As a result, the valve body 22 locked by the lock portion 24 comes into close contact with the valve seat 23 due to the urging force thereof to be brought to the closed position.

In order to return the valve body 22 in the closed position to the open position, the lid 32 is removed and the valve
2 may be locked to the lock portion 24. Thereby, it becomes possible to perform a manual return without removing the shut-off valve unit 11.

As described above, according to the shut-off valve unit of the present embodiment, the lock portion 24 is operated by the shape memory alloy, and the lock portion 24 is held at the lock position in the normal temperature range. The body 22 is locked in the open position, and in the low temperature range, the lock portion 24 is displaced to the unlocked position to release the lock of the valve body 22 in the open position. Even if not used, the locking member 19 itself can detect the temperature and shut off the flow path by itself, thereby eliminating the need to construct a system.

Further, since the piston 27 in which the first spring member 29 is located is cup-shaped, fluid accumulates in the piston 27 and the first spring member 29 is easily immersed in the fluid. Thereby, the first spring member 2 for the fluid
9 can increase the response speed.

Since the liquefaction temperature of LNG is -160.degree. C., in this embodiment, the elasticity of the first spring member 29 is lost at -40.degree. The valve body 22 is set to be displaced to the unlocking position, whereby the valve body 22 is brought to the closed position.

However, as the fluid, LNG (liquefaction temperature:-
160 ° C.), for example, liquid nitrogen (liquefaction temperature: −196 ° C.), liquid air (liquefaction temperature: −−
190 ° C.), liquefied ethylene (liquefaction temperature: −104 ° C.), and other various low-temperature fluids can be applied. Therefore, the temperature at which the first spring member 29 loses its elastic force can be set freely according to the temperature of the target fluid.

In the present invention, a high-temperature fluid may be used instead of a low-temperature fluid. Therefore, in this case, the second temperature range may be a high temperature range instead of a low temperature range.

Further, the first temperature range is not a normal temperature range, and the second temperature range is not a low temperature range or a high temperature range. Conversely, the first temperature range is a low temperature range or a high temperature range, and the second temperature range is a low temperature range or a high temperature range. Is the normal temperature range, the open position in the low temperature range or high temperature range,
The lock portion 24 can be set to be in the closed position in the normal temperature range.

The normal temperature range and the low temperature range, and the normal temperature range and the high temperature range are relative concepts, and do not indicate a specific numerical range. That is, the higher the temperature between the normal temperature range and the low temperature range is the normal temperature range, and the higher the temperature between the normal temperature range and the high temperature range is the high temperature range. Therefore, the first temperature range and the second temperature range are also relative concepts and not a concept indicating a specific numerical range, and the higher (lower) temperature is the first temperature range, The lower (higher) temperature is the second temperature range.

Here, in the process of inventing the shut-off valve unit of the present invention described above, the present inventor has made the following use of a shape memory alloy having the property of hardening at room temperature and bending at low or high temperature. Two types of technologies were considered.

The first technique is to directly open and close the valve element with a spring-shaped or plate-shaped shape memory alloy.

However, according to the first technique, the valve body remains in the flow path even at the open position, so that not only can the fluid not flow sufficiently, but also when the valve body is placed outdoors, the valve body is made of solid material. There was a risk that the flow path would be closed at the position. Further, there is also a problem in workability for returning the valve element in the closed position to the open position due to its structure.

The second technique is to hold the open position by making the shape memory alloy a wire and locking the valve directly.

According to the second technique, it is possible to use an oscillating valve element with a hinge that does not remain in the flow path at the open position. Therefore, it is possible to solve the above-described problem in the first technique. it can.

However, it has been found that when trying to ensure flexibility in a low temperature range or a high temperature range, the strength for supporting the valve body in a normal temperature range is insufficient. When the diameter of the wire, which is a shape memory alloy, is increased to avoid such inconvenience, the shape memory alloy does not bend in a low temperature range or a high temperature range, and the valve cannot be closed.

Further, even if the valve body which has been in the closed position in the low temperature range or the high temperature range is to be returned to the open position, if the shape memory alloy is hardened in the normal temperature range at the time of the operation, the valve body is reset. I can't let it.

For such a reason, the second technique could not be adopted.

The present invention relates to the first spring member 29 and the second spring member 29.
The holding of the valve body 22 is ensured because of the actuator type in which the lock portion 24 is actuated with the spring member 30 of FIG. The first spring member 29 made of a shape memory alloy
Even if is cured at room temperature, it is possible to return the valve body 22 by pushing it back. Therefore, the present application has solved the problem in the second technique.

In the present embodiment, the lock portion 24 is moved between the locked position and the unlocked position by the movement of the piston, but other forms such as a swinging motion may be adopted. it can. In other words, various structures can be adopted as the locking member as long as the locking member 24 is driven by the shape memory alloy whose characteristics change depending on the temperature.

[0054]

As apparent from the above description, the following effects can be obtained according to the present invention.

(1) Even without using a power source or a heat sensing system, the locking member itself can detect the temperature and can shut off the flow path by itself, thereby eliminating the need for system construction.

(2) This makes it possible to obtain a shut-off valve unit that is low in cost, easy in installation work, and low in maintenance cost.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a plant using a shut-off valve unit according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view showing a shut-off valve unit according to an embodiment of the present invention.

FIG. 4 is a perspective view showing a locking member in the shut-off valve unit of FIG. 3;

FIG. 5 is an explanatory view showing the locking member of FIG. 4 held at a locking position.

FIG. 6 is an explanatory view showing the locking member of FIG. 4 held at a locking release position.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Shut-off valve unit 12 Plant 13 Equipment 14 Piping 15 Rainwater pan 16 Drainage pipe 17 Housing 17a Fixed part 18 Shut-off valve 19 Locking member 20 Hinge pin 21 Arm 22 Valve body 23 Valve seat 24 Lock part 25 Shaft 26 Frame 26a Base 26a ₁ opening Part 26b mounting part 27 piston 28 flange 29 first spring member 30 second spring member 31 cover 31a hole 32 lid

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoichi Kono 2040 Nagasaka-Kamijo, Nagasaka-cho, Nagakaka-gun, Kita-Koma-gun, Yamanashi F-term in Kitz Nagasaka Plant (Reference) 3H052 AA02 BA25 BA26 BA32 CD02 EA01 3H057 AA06 BB26 BB32 CC04 DD13 FA23 FC04 HH07 3H058 AA07 BB22 BB28 DD13 EE05

Claims (6)

[Claims] 1. A housing, a shutoff valve installed in the housing and provided with a biasing force for holding the valve body in a closed position to open and close a flow path; and opening the valve body in a first temperature range. The lock portion is held at a lock position where the lock portion is locked at the position, and in the second temperature range, the lock portion is allowed to be displaced to a lock release position where the lock at the open position of the valve body is released. A locking member provided with a shape memory alloy, wherein the lock portion holds the valve body at the locking position if a temperature changes from the first temperature range to the second temperature range. Wherein the valve body is displaced to the unlocked position so that the valve body is brought to the closed position by the urging force. 2. A housing, a shut-off valve installed in the housing and provided with a biasing force for holding the valve body at a closed position to open and close a flow path, and a lock for locking the valve body at an open position. A lock portion displaceably provided between a lock position and a lock release position for releasing the lock of the valve body at the open position. In the first temperature range, the lock portion is moved to the lock position by a resilient force. A first spring member made of a shape memory alloy that retains and loses its elasticity in the second temperature range, and allows the elasticity of the first spring member in the first temperature range. A locking member made of a second spring member for displacing the lock portion to the unlocked position by a resilient force due to a loss of resilience of the first spring member in a second temperature range, Temperature changed from the first temperature range to the second temperature range The shut-off valve, wherein the lock portion holding the valve body at the locking position is displaced to the unlocking position so that the valve body is brought to a closed position by the urging force. unit. 3. The locking member includes: a cup-shaped piston having an opening formed therein and having the lock portion attached thereto via a shaft in a direction opposite to the opening; and a piston mounted on the piston. The first spring member that presses in the direction of the locking position of the lock portion; and the first spring member that is attached to the outer periphery of the piston and presses the piston in the direction of the unlocking position of the lock portion that is in a direction opposite to the locking position. 3. The shut-off valve unit according to claim 2, further comprising: the second spring member. 4. The shut-off valve unit according to claim 1, wherein a cover having a plurality of holes formed therein is attached to the locking member. 5. The valve element according to claim 1, wherein the valve element swings by a swing fulcrum provided on the housing, a spherical valve element rotatably disposed on the flow path, or an axial displacement of the flow path. The shut-off valve unit according to any one of claims 1 to 4, wherein the shut-off valve unit is a freely disposed valve body. 6. The shut-off valve unit according to claim 1, wherein a detachable or openable / closable lid is provided on a side of the shut-off valve in the housing.