TWI461620B - Relief valve - Google Patents

Description

Release valve

The present invention relates to a release valve for use in a sealed container such as a tank, and when the pressure in the sealed container reaches a set value, the gas in the sealed container is discharged to the outside to ensure the robustness of the sealed container.

In the sealed container, the internal pressure may rise and reach a predetermined pressure or higher due to a change in temperature or a change in internal vapor pressure.

For example, regarding the groove provided as a sealed container such as a chemical liquid ship or a tanker, the internal pressure may increase due to the compression of the gas in the tank due to the loading of the cargo. Further, for safety reasons, an inert gas or the like is filled in the remaining space portion in which the cargo has been loaded. In this case, there is a case where the inert gas expands due to the temperature and the internal pressure rises.

In order to suppress such a pressure rise, a relief valve is provided in the hermetic container, and when the internal pressure reaches the set pressure, the gas in the hermetic container is discharged to the outside to maintain the internal pressure within the set pressure.

For example, in the release valve provided in a chemical liquid ship or the like, the exhaust gas is exhausted upward at a high speed of 30 m/sec or more from the time of opening the valve to the time of closing the valve to prevent fire from entering the tank. Security measures.

In order to maintain the exhaust speed at a high speed of 30 m/sec or more, it is necessary to increase the valve opening speed of the valve body. Regarding the method of using the internal pressure of the tank to accelerate the valve opening speed of the valve body, a first pressure receiving surface for opening the valve body at a set pressure is provided. And a method of increasing the valve opening speed by applying the internal pressure of the groove from the first pressure receiving surface to the second pressure receiving surface, and having the second pressure receiving surface larger than the area. According to this method, since the force for lifting the valve body increases in accordance with the area ratio of the first pressure receiving surface and the second pressure receiving surface, the valve opening speed can be further increased by increasing the area ratio.

However, in this case, if the pressure is not sufficiently lower than the set pressure required to open the valve, the valve is not closed, so that a large amount of inert gas is discharged.

This is because the function of the second pressure receiving surface for speeding up the valve opening is reversed during the valve closing operation.

In this regard, the technique described in Patent Document 1 aims to prevent the repetition of the opening and closing operation of the release valve due to the pressure change of the exhaust gas when the internal gas is discharged, and to provide the valve body to the lower side when the valve is closed. The magnet speeds up the valve closing speed and allows for an early sealing action when the pressure drops below the set pressure.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 4282326

However, there is a problem to be solved by the method of attracting the valve body to the magnet below.

(1) Increasing manufacturing costs with magnets using expensive parts.

(2) Not only magnets, but also the number of parts such as magnet mounting means will increase.

(3) Most of the release valves are installed on oil tankers, etc., so the magnets will be rotted. Corrosive gas and corrosion.

(4) Since the magnet attracts iron, the iron easily adheres to the valve box in which the magnet is present.

Further, the pressure valve described in Patent Document 1 has a space for improvement in reactivity with respect to the valve opening operation.

As a result, the reactivity of the conventional valve opening operation and the reactivity of the valve closing operation are difficult to achieve.

For the above reasons, it is desirable to have a new solution for improving the reactivity in the gas discharge operation at the time of valve opening and the sealing operation at the time of valve closing.

The present invention has been made in view of the above-described problems, and an object of the invention is to provide a gas discharge operation when the pressure in a sealed container exceeds a set value and a reaction of a sealing operation when a pressure is lower than a set value. Novel new technology.

In order to solve the above problem, the release valve according to the first aspect of the present invention includes: a valve body; and a valve box formed with a valve seat that is biased and hermetically abutted by the valve body, and is guided to When the pressure of the gas of the valve box reaches a set value, the valve body is separated from the valve seat by the pressure and the gas in the valve box is discharged to the outside. The release valve is characterized in that: the valve body is provided with The valve body is integrally formed with a movable body that forms a flow path of the gas between the inner wall of the valve casing, and the valve body is formed with a first pressure receiving surface that is constantly subjected to pressure in the valve casing. And a second pressure receiving surface, which is subjected to pressure in the valve box when the valve body leaves the valve seat, and the movable body is formed to be subjected to pressure in the valve box The third pressure receiving surface is formed on the inner wall of the valve casing, and the valve body interacts with the movable body to form a small diameter portion that reduces the flow path when leaving the valve seat.

With such a configuration, when the pressure in the valve box reaches a predetermined pressure, the valve body and the movable body move in the valve opening direction by acting on the first pressure receiving surface formed on the valve body.

At the beginning of the valve opening operation, when the valve body is separated from the valve seat, the second pressure receiving surface formed on the valve body communicates with the valve box, and the pressure in the valve box acts on the second pressure receiving surface. The force acting on the second pressure receiving surface is applied to the valve body to accelerate the valve opening operation of the valve body.

In a state where the valve body is in the valve closing position, the gas pressure surrounding the movable body inside the valve casing is fixed, and therefore the force in the opening and closing direction of the valve does not act on the movable body.

When the valve opening operation is performed by the force acting on the first pressure receiving surface and the second pressure receiving surface, the pressure on the valve body side (ie, the downstream side of the flow path) of the movable body is lowered, and the movable body is directed to the valve opening direction. The force of the movement is newly applied to the upstream side of the flow path of the movable body.

Thereby, the valve opening operation of the valve body is accelerated.

When the valve opening operation is further performed, the movable body moves to the small diameter portion of the valve casing to narrow the flow path in the valve casing, whereby the gas pressure on the upstream side of the movable body rises and acts on the valve opening direction of the movable body. The force is increased to further accelerate the valve opening action of the valve body.

In this way, the force acting on the second pressure receiving surface is applied to the force acting on the first pressure receiving surface, and after the force acting on the movable body is further applied, the force increases as the pressure increases, thereby rapidly performing the valve body. Open the valve.

Further, the valve closing operation is performed in the opposite operation to the above-described valve opening operation, and the movable body is separated from the small diameter portion of the valve casing and located in the large diameter portion before the pressure is effectively applied to the second pressure receiving surface.

At this time, since the gas pressure on the upstream side of the movable body is lowered, the force applied to the movable body in the valve opening direction is reduced.

At this time, when the valve body is moving in the valve closing direction, the valve body is abutted against the valve seat to close the release valve due to the inertial force and the force acting in the valve opening direction acting toward the movable body.

Therefore, the valve body is quickly closed.

Further, the amount of force reduction in the valve opening direction acting toward the movable body can be adjusted by changing the difference in inner diameter between the small diameter portion and the large diameter portion of the design valve box, and if the amount of reduction is set to be larger than the valve closing in advance The force in the valve opening direction generated on the second pressure receiving surface during the operation further accelerates the valve closing operation.

Further, the adjustment of the amount of decrease in the force in the valve opening direction acting on the movable body may be performed by adjusting the pressure at the time of valve closing, thereby setting the valve closing time with respect to the set pressure at the time of valve opening. pressure.

Therefore, the pressure at the time of valve closing can be made close to the set pressure at the time of valve opening, and excessive gas discharge can be suppressed and excessive pressure drop in the sealed container provided with the relief valve can be suppressed.

Further, it is considered that the pressure at the time of valve closing is preferably about 70% to 80% of the set pressure at the time of valve opening.

As described above, when excessive gas discharge is suppressed, for example, it is expected to reduce the management cost by reducing the discharge amount of the inert gas or the like filled based on safety considerations.

Characteristics of the relief valve of the second application of the present invention The area of the third pressure receiving surface described in the first paragraph of the patent application is larger than the first pressure receiving surface.

With such a configuration, the valve opening operation of the valve body can be made more rapid.

The release valve according to the third aspect of the invention is characterized in that the movable body according to the first aspect of the invention has a large diameter portion and a small diameter portion, and is movable when the valve body is separated from the valve seat. The flow path is narrowed between the large diameter portion of the body and the small diameter portion of the valve box.

In such a configuration, the large-diameter portion of the movable body can be provided with a function as a valve body by a simple structure, and the small-diameter portion of the valve box can have a function as a valve seat.

The valve according to the fourth aspect of the invention, wherein the valve body according to the first to third aspects of the invention is configured such that the valve body is airtight so as to surround the second pressure receiving surface. A guide portion that is slidably fitted in the state.

According to this configuration, the amount of gas exhausted from the second pressure receiving surface is suppressed by the guide portion, and the force acting on the second pressure receiving surface is surely obtained.

The release valve according to the fifth aspect of the invention is characterized in that the valve body and the movable body according to the first to fourth aspects of the invention are designed to be movable in a vertical direction, and the valve body is provided by the same The mass is pressed toward the aforementioned valve seat.

With such a configuration, the conditions for the valve opening operation and the valve closing operation, the areas of the various pressure receiving surfaces, and the size of the movable body are performed only for the total mass of the mass of the valve body and the mass of the movable body. Since the size of the small diameter portion or the like is set, the setting is simple and easy.

According to the present invention, it is possible to increase the reactivity of the gas discharge operation when the pressure in the sealed container exceeds the set value and the sealing operation when the pressure is lower than the set value.

[Formation of the Invention]

Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 3 .

In Fig. 1, reference numeral 1 denotes a release valve according to this embodiment. The release valve includes a valve body 2, a gas inlet port 3a that is attached to a sealed container (not shown), and communicates with the inside; and the valve box 3 has a gas discharge port 3b that discharges the gas in the sealed container to the outside.

The movable body 4 in which the gas passage L is formed between the valve body 2 and the inner wall of the valve casing 3 is provided coaxially. The valve body 2 is formed with a first pressure receiving surface 2a that is constantly subjected to pressure in the valve casing 3, and a second pressure receiving surface 2b that is separated from the gas discharge port 3b formed in the valve casing 3 by the valve body 2. When the valve seat 3c having a substantially truncated conical shape on the inner surface is subjected to the pressure in the valve casing 3 described above. The third pressure receiving surface 4a larger than the first pressure receiving surface 2a is formed in the movable body 4. In the inner wall of the valve casing 3, when the valve body 2 is separated from the valve seat 3c, a small-diameter portion 3d that narrows the flow path L is formed to interact with the movable body 4, and the small-diameter portion 3d is upstream. The side constitutes the large diameter portion 3e. 3f is the mounting part of the suction valve.

The valve body 2 and the movable body 4 are integrally attached to an upper end portion and a substantially intermediate portion of the rod 5 which is attached to the center portion of the valve casing 3 in a single direction (in the vertical direction of the present embodiment).

In other words, the movable body 4 is fitted to the rod 5 and is fixed to the stopper of the rod 5 in a state where the movement in the axial direction is restricted via the plug 6. 7. The nut 8 screwed to the stopper 7 at a predetermined interval is fixed to the rod 5.

The valve body 2 is fitted to the rod 5, and is clamped and fixed by a segment (not shown) formed beside the upper end portion of the rod 5 and a nut 9 screwed to the end of the rod 5.

Further, the second pressure receiving surface 2b formed in the valve body 2 is formed into an outer surface shape substantially the same as the inner surface of the valve seat 3c, and is airtightly abutted against the valve seat 3c.

The valve casing 3 is composed of a main body 10 having a cylindrical shape and having a strut 10a formed at a substantially intermediate portion thereof, and a lid body 11 detachably attached to an upper end portion of the main body 10.

In the center of the above-mentioned strut 10a, the guide sleeve 12 to which the rod 5 is slidably fitted is integrally attached. Further, the valve seat 3c is formed on the inner surface of the upper end portion of the lid body 11, and an introducer that slidably fits the rod 5 is integrally provided by a plurality of struts 14 in a substantially intermediate portion in the vertical direction. 13.

The relief valve 1 of the present embodiment configured as described above is closed as shown in Fig. 1 by the entire peripheral surface of the second pressure receiving surface 2b of the valve body 2 being airtightly abutted against the valve seat 3c of the lid body 11. Valve status.

In the present embodiment, the valve body 2 and the valve seat 3c are formed by the mass of the valve body 2, the movable body 4, and the rod 5 or the stopper 7, the plug 6, the nut 8, the nut 9, and the like. The abutment.

In the release valve 1 that is connected to a sealed container (not shown) such as a tank of a tanker, the pressure inside is balanced with the pressure in the sealed container, and the pressure acts on the first pressure receiving surface of the valve body 2. 2a, and the role is The force in the direction of the valve opening.

Further, in the movable body 4, since the valve body 2 is located at the valve closing position and the entire peripheral surface acts with an equal pressure, the force generated by the gas does not act.

When the pressure in the sealed container rises, the pressure in the valve box 3 also rises, and the force acting on the first pressure receiving surface 2a in the valve opening direction increases, and when the pressure is equal to or higher than the set pressure, the valve body 2 moves in the opening direction.

As the valve body 2 moves in the opening direction, the second pressure receiving surface 2b is separated from the valve seat 3c, and pressure is applied to the second pressure receiving surface 2b, and a force in the valve opening direction is generated, together with the first pressure receiving surface 2a. The force applied causes the valve body 2 to move in the valve opening direction.

Further, as shown in Fig. 2, when the valve opening operation of the valve body 2 continues, the valve casing 3 is largely opened, and the pressure on the valve seat 3c side of the movable body 4 is lowered.

As a result, a pressure difference is generated on the upstream side and the downstream side of the flow path L of the movable body 4, whereby the movable body 4 moves in the valve seat 3 direction by the pressure difference.

Further, by the movement of the movable body 4, the movable body 4 moves toward the small-diameter portion 3d of the valve box 3, and the flow path L is narrowed, and the pressure on the upstream side of the movable body 4 rises, thereby improving the opening of the movable body 4. The pushing force in the direction of the valve.

In this way, a plurality of pressing forces act in combination with the valve opening direction, and the valve opening speed is remarkably improved.

When the pressure in the sealed container is lower than the set pressure, the valve closing operation is started. When the valve is closed, the force for moving the valve body 2 in the opening direction is rapidly reduced by the movement of the movable body 4 toward the large diameter portion 3e. .

Therefore, the valve body 2 is rapidly moved toward the valve closing position, and the inertia force is combined to perform rapid valve closing.

Moreover, the shapes, dimensions, and the like of the respective structural members shown in the above-described embodiments are merely examples, and can be variously changed based on design requirements and the like.

For example, as shown in FIG. 3, the valve body 3 is formed so as to surround the second pressure receiving surface 2b so as to form the guide portion 15 in which the valve body 2 is slidably fitted in an airtight state, thereby improving the orientation. The action of the pressure of the second pressure receiving surface 2b.

Further, the movable body 4 of the above-described embodiment is an example in which a thick-diameter cylindrical member is cut and a small-diameter portion and a large-diameter portion are formed. As shown in Fig. 4, the movable body 4 may be a tubular main body portion 41. And a circular plate 42 with a hole fixed to the upper end portion.

In the case of such a configuration, the manufacturability of the movable body 4 itself is easy, and further cost reduction can be achieved.

1‧‧‧ release valve

2‧‧‧ valve body

2a‧‧‧1st pressure receiving surface

2b‧‧‧2nd pressure-receiving surface

3‧‧‧ valve box

3a‧‧‧ gas inlet

3b‧‧‧ gas discharge

3c‧‧‧ seat

3d‧‧‧Little Trails Department

3e‧‧‧Great Path Department

3f‧‧‧Intake valve installation

4‧‧‧ movable body

4a‧‧‧3rd pressure-bearing surface

5‧‧‧ pole

6‧‧‧ bolt

7‧‧‧stop

8‧‧‧ nuts

9‧‧‧ Nuts

10‧‧‧ Ontology

10a‧‧‧ pole

11‧‧‧ Cover

12‧‧‧ Guide sleeve

13‧‧‧ Introducer

14‧‧‧ pole

15‧‧‧Guidance

41‧‧‧ Body Department

42‧‧‧round plate with holes

L‧‧‧Flow

Fig. 1 is a longitudinal section showing an embodiment of the present invention.

Fig. 2 is a longitudinal section for explaining the operation of an embodiment of the present invention.

Fig. 3 is an enlarged longitudinal sectional view showing the main part of an embodiment of the present invention.

Fig. 4 is a front elevational view showing another embodiment of the movable body of the present invention.

1‧‧‧ release valve

2‧‧‧ valve body

2a‧‧‧1st pressure receiving surface

2b‧‧‧2nd pressure-receiving surface

3c‧‧‧ seat

3d‧‧‧Little Trails Department

3e‧‧‧Great Path Department

4‧‧‧ movable body

5‧‧‧ pole

8‧‧‧ nuts

9‧‧‧ Nuts

10‧‧‧ Ontology

11‧‧‧ Cover

13‧‧‧ Introducer

14‧‧‧ pole

15‧‧‧Guidance

Claims (4)

A release valve comprising: a valve body; and a valve box formed with a valve seat that is elastically abutted by the valve body, and the valve is when the pressure of the gas guided to the valve box reaches a set value The body is discharged from the valve seat by the pressure, and the gas in the valve box is discharged to the outside. The release valve is characterized in that: the valve body is provided integrally with the valve body and the inner wall of the valve box a movable body that forms a flow path of the gas, and the valve body is formed with a first pressure receiving surface that is always subjected to a pressure in the valve casing; and a second pressure receiving surface that leaves the valve body from the valve seat When the pressure is applied to the valve body, the movable body is formed with a third pressure receiving surface that receives the pressure in the valve box, and a small diameter portion is formed in the inner wall of the valve box. When leaving the valve seat, the flow path is reduced by the interaction with the movable body, and the second pressure receiving surface is formed as an inclined surface that is in airtight contact with the valve seat, and the second pressure is surrounded by the valve box. The surface is formed with a guiding portion that makes the valve body An outer peripheral surface slidably fitted in an airtight state, the guide portion rising from the line offset from the moving direction of the valve seat portion of the outer periphery of the valve member along the valve seat. The release valve of claim 1, wherein the third pressure receiving surface is larger than the first pressure receiving surface. The release valve of claim 1 or 2, wherein the movable body has a large diameter portion and a small diameter portion, and when the valve body is separated from the valve seat, the large diameter portion of the movable body and the small diameter of the valve box The aforementioned flow path is narrowed between the parts. The release valve of claim 1, wherein the valve body and the movable body are arranged to be movable in a vertical direction, and the valve body is biased toward the valve seat by mass.