JP2566186Y2 - Drain valve for liquefied gas - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquefied gas drain valve for discharging a liquefied gas leaked from a liquefied gas storage tank due to breakage of the liquefied gas storage tank.

[0002]

2. Description of the Related Art A conventional liquefied gas drain valve for discharging a liquefied gas to the outside when a liquefied gas storage tank leaks from the storage tank due to a partial breakage of the liquefied gas storage tank is shown in FIG. There is a configuration as shown.

That is, a conventional liquefied gas drain valve a
The liquefied gas passes from the inlet side I to the outlet side O through the space between the valve plate d and the valve seat e by separating the valve plate d from the valve seat e against the spring c by the supply of the compressed air b. And the supply of the compressed air b is performed from the air compressor f via the solenoid valve g, and the heat insulating material is formed so as to form the void 2 outside the liquefied gas storage tank main body 1. In the liquefied gas storage tank in which the liquefied gas storage tank 3 is disposed, the inlet side I of the drain valve a
Is attached via a valve inlet pipe h, so that the liquefied gas b leaked from the inside of the liquefied gas storage tank body 1 reaches the valve inlet pipe h from the outlet 4 of the gap 2. A low temperature sensor i is attached to the tube h.
j is a valve outlet pipe and k is a tray.

When the liquefied gas 1 leaks into the gap 2 due to, for example, partial breakage of the liquefied gas storage tank body 1, and further reaches the valve inlet pipe h from the gap 2, the low-temperature sensor i is activated to operate the low-temperature sensor i. The signal from the sensor i is the solenoid valve g, the air compressor f
And the air compressor f is operated to supply the compressed air b to the drain valve a through the solenoid valve g. When the valve plate d separates from the valve seat e, the liquefied gas entering the valve inlet pipe h passes from the inlet side I to the outlet side O, and flows into the tray k via the valve outlet pipe j.

[0005]

However, in the above-mentioned conventional liquefied gas drain valve, a control device such as a low-temperature sensor i for operation of the valve, a solenoid valve g, etc., and a valve such as an air compressor f, an air pipe, etc. There is a problem that a drive power unit is required, the device is complicated and expensive, and in the case of a flammable fluid, explosion-proof measures are required, and uneconomical in terms of quality control and physical quantity.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a drain valve for a liquefied gas which has a simple structure and can be reliably operated without requiring power.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a plurality of sheets which are deformed outward at low temperature and deformed inward at high temperature, and a stopper is attached at a lower end so as to project inward. Each upper end of the plate bimetal is attached to the upper part of the cylindrical valve box with a bimetal fixing hardware, and the lower end of each plate bimetal deforms inward and outward depending on the temperature in the valve box, and the stopper moves inward and outward. The coil spring holder for sealing which is suspended between the respective plate bimetals at the lower end of a rod which is suspended and supported so that it can be A valve plate that is slidably fitted on the rod, a valve-opening coil spring holder is screwed up and down on the upper part of the rod, and the lower end of the valve box is closed at the lower end of the rod. Take The sealing coil spring holder is provided with an engaging portion for engaging and receiving the upper surface of the stopper at the lower end of each plate bimetal, and the sealing coil spring holder and the valve opening coil spring are provided. A sealing coil spring for pressing the sealing coil spring holder against the stopper between the holder and the holding member, and a valve plate between the valve opening coil spring holder and the bimetal fixing hardware via a rod. The valve is opened downward by pushing the valve downward to open the valve. The sealing coil spring has a greater spring force than the valve opening coil spring. The seal device is interposed between the end face and the end face.

[0008]

When the low temperature liquefied gas inside leaks into the gap due to breakage of the liquefied gas storage tank body, the gas enters the valve box through the gap. This lowers the temperature of the plate bimetal in the valve box and deforms it, so the stopper at the lower end of the plate bimetal comes off and the sealing coil spring is opened, but at the same time the rod is pushed down by the valve opening coil spring. Moving downward, the valve is opened, and the liquefied gas is discharged outside the valve.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an embodiment of the present invention. Similar to the liquefied gas storage tank shown in FIG. 4, a heat insulating material 3 is disposed outside a liquefied gas storage tank body 1.
A liquefied gas drain valve according to the present invention is provided at the outlet 4 of the liquefied gas storage tank having a structure in which a space 2 serving as a flow path is formed between the liquefied gas storage tank body 1 and the heat insulating material 3. 5 is attached.

The liquefied gas drain valve 5 of the present invention is mounted on a cylindrical valve box 7 fixed to a valve box mounting piece 6 fixed at the position of the outlet 4 of the gap 2 and is screwed into an upper portion of the valve box 7. And a stopper 11 attached to a lower end thereof is disposed in parallel with each other so as to face each other. Plate bimetal 10 attached to
And a rod 13 positioned at the center of the valve box 7 and a stopper 15 at the lower end of each of the plate bimetals 10 so that the stopper 15 is engaged with the stopper 11. A sealing coil spring holder 14 slidably fitted to the lower end of a rod 13 and a valve opening screwed to a screw portion 16 on the upper portion of the rod 13 so as to be freely movable in the vertical direction. Coil spring holder 17, a valve opening coil spring 18 interposed between the valve opening coil spring holder 17 and the bimetal fixing hardware 8, and a valve opening coil spring holder 17 for sealing. A sealing coil spring 19 interposed between the coil spring holder 14, a valve plate 20 detachably screwed to a lower end of the rod 13, and a lower end surface of the valve box 7 and the valve plate 20. A packing 21 for sealing between There a configuration, further, the plate bimetal 10, as shown in FIG. 3, the outer surface side low-expansion metal,
The inner surface side is made of high expansion metal, and two kinds of metals are bonded together and then formed by rolling. The sealing coil spring 19 has a larger spring force than the valve opening coil spring 18. is there.

When the liquefied gas storage tank is normal,
The drain valve 5 of the present invention fills the gap 2 in the closed state with N ₂
No gas or dry air flow is generated and the storage tank body 1
Can be maintained at a low temperature, so that the amount of vaporized liquefied gas in the storage tank body 1 can be kept small, which is economical.

When a part of the liquefied gas storage tank body 1 is damaged and the liquefied gas 22 inside flows into the gap 2 as shown in FIG. 3, it passes through the gap 2, from the outlet 4 of the gap 2 to the valve inlet 9. And enter the inside of the valve box 7. When the liquefied gas 22 enters the valve box 7 and flows down, the temperature in the valve box 7 is reduced by the liquefied gas 22, so that the temperature of the plate bimetal 10 is also reduced.

Since the plate bimetal 10 has a configuration in which the outer surface side is bonded with a low expansion metal and the inner surface side is bonded with a high expansion metal, the plate bimetal 10 is bent outward as shown in FIG. When the stopper 11 at the lower end of the plate bimetal 10 curves to a position where it can be detached from the engaging portion 15 of the sealing coil spring holder 14, the engaging portion 15 of the sealing coil spring holder 14 moves from the stopper 11 Leaves instantly. Thereby, the sealing coil spring 19
Is released and loses elasticity, and at the same time, the valve opening coil spring 18 is opened.
Is released, the rod 13 is pushed down, the valve plate 20 moves downward, and the valve is opened.

In the above, the amount of compression of the valve opening coil spring 18 can be adjusted by moving the valve opening coil spring holder 17 up and down.

The liquefied gas 22 that has entered the valve box 7 due to the above-mentioned valve opening state is discharged through the space between the lower end of the valve box 7 and the valve plate 20.

On the other hand, when a small amount of the liquefied gas 22 leaks into the gap 2, the gas may be vaporized before reaching the valve inlet 9. By selecting the spring force so that the force of the coil spring 19 for use is small, the valve box
Internal pressure can overcome the sealing coil spring 19 and push down the valve plate 20 to bring the valve open.

In this case, even if the pressure in the gap 2 increases due to the vaporization of the leaked liquefied gas, the allowable limit pressure in the gap 2 is calculated in advance, and the external force applied to the valve plate 20 is calculated based on the pressure. If the reaction force of the sealing coil spring 19 is selected to be smaller than the external force, even if the liquefied gas is vaporized, the valve plate 20 can be pushed down to open the valve, and the vaporized gas can be removed. Can be discharged outside.

It should be noted that the present invention is not limited to the above embodiment. For example, the case where two plate bimetals 10 are used is shown. Of course, various changes can be made without departing from the scope.

[0020]

As described above, according to the liquefied gas drain valve of the present invention, a plurality of stoppers are formed such that they are deformed outward at low temperatures and deformed inward at high temperatures, and a stopper is provided at the lower end so as to project inward. The upper end of each plate bimetal is attached to the upper part of the cylindrical valve box with a bimetal fixing hardware, and the lower end of each plate bimetal is deformed inward and outward depending on the temperature in the valve box, and the stopper moves inward and outward. The coil spring holder for sealing placed between the respective plate bimetals at the lower end of a rod that is suspended and supported so that it can be displaced in the Along with slidingly fitting in the direction, a valve-opening coil spring holder is screwed on the upper part of the rod so as to be vertically movable,
Further, a valve plate for closing the lower end of the valve box is attached to the lower end of the rod, and the sealing coil spring holder is engaged with the upper surface of the stopper at the lower end of each plate bimetal so as to be received. A sealing coil spring for pressing the sealing coil spring holder against the stopper between the sealing coil spring holder and the valve opening coil spring holder, and a valve. A valve-opening coil spring for opening the valve by pushing down the valve plate via a rod between the holding member for opening the coil spring and the metal fitting for fixing the bimetal is interposed. Since the spring force is made larger than that of the valve opening coil spring and the sealing device is interposed between the upper surface of the valve plate and the lower end surface of the valve box, the following excellent effects can be obtained. (i) It has a simple structure utilizing the inward and outward deformation of the lower end of the plate bimetal and the reaction force of the coil spring, and can be operated automatically and reliably without requiring power. (ii) By adjusting the width of the engaging portion of the sealing coil spring retainer that engages with the stopper at the lower end of the plate bimetal, the temperature at the time of opening the valve can be set, and until the set temperature is reached. The valve plate can be prevented from opening. (iii) By adjusting the compressive strength of the valve opening coil spring and the sealing coil spring, the valve opening state due to the pressure in the gap can be set. (iv) If necessary, the valve can be easily opened and closed manually by pulling the valve plate downward, so that if there is a fluid inside, it can be easily discharged.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a liquefied gas drain valve of the present invention.

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

FIG. 3 is a cross-sectional view of the liquefied gas drain valve according to the present invention when the valve is opened.

FIG. 4 is a sectional view showing an embodiment of a conventional liquefied gas drain valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquefied gas storage tank main body 2 Air gap 3 Insulating material 5 Drain valve for liquefied gas 7 Valve box 8 Bimetal fixing hardware 10 Plate bimetal 11 Stopper 13 Rod 14 Sealing coil spring holder 15 Engagement part 17 Valve opening coil spring holder 18 Coil spring for valve opening 19 Coil spring for sealing 20 Valve plate 21 Packing (seal device)

Continuation of front page (56) References JP-A-57-184774 (JP, A) JP-A-56-151569 (JP, U) JP-A-61-202775 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] An upper end of a plurality of plate bimetals, which are deformed outward at low temperature and deformed inward at high temperature, and have stoppers attached to the lower end so as to project inward, are connected to each other in a cylindrical valve box. Attached to the upper part with a bimetal fixing hardware, the lower end of each plate bimetal is deformed inward and outward according to the temperature in the valve box, and is suspended and supported so that the stopper can be displaced inward and outward, and the inside of the valve box A sealing coil spring holder, which is located between the respective plate bimetals, is slidably fitted in the vertical direction at the lower end of a rod arranged in the center in a vertical direction, and a valve is opened on the upper part of the rod. And a valve plate for closing a lower end of the valve box is attached to a lower end of the rod, and the sealing coil spring holder is provided with the respective plates. Baime An engaging portion is provided for engaging and receiving the upper surface of the stopper at the lower end of the barrel, and the sealing coil spring holder is provided between the sealing coil spring holder and the valve opening coil spring holder. And a valve-opening coil that opens the valve by pushing down a valve plate via a rod between the valve-opening coil spring holder and the bimetal fixing hardware through a rod. Each of the springs is interposed, the sealing coil spring has a greater spring force than the valve opening coil spring, and a sealing device is interposed between the upper surface of the valve plate and the lower end surface of the valve box. Liquefied gas drain valve.