JPH0575575U - Drain valve for liquefied gas - Google Patents

Abstract

(57) [Summary] [Purpose] A simple structure ensures reliable operation. [Structure] An upper end of a plate bimetal 10 is attached to an upper position inside a tubular valve box 7 with a bimetal fixing hardware 8. A stopper 11 is provided at the lower end of the plate bimetal 10.
The coil spring holder 14 for sealing is slidably fitted to the lower end of the rod 13 which is located at the center of the valve box 7 and has the valve plate 20 attached to the lower end. A valve opening coil spring holder 17 is screwed onto the upper portion of the rod 13. The stopper 11 engages with the engaging portion 15 of the sealing coil spring holder 14, and the space between the sealing coil spring holder 14 and the valve opening coil spring holder 17 is between the valve opening coil spring holder 17 and the bimetal. Coil springs 19 and 18 are respectively provided between the fixed hardware 8.
There is. The plate bimetal 10 is deformed by the temperature and the stopper 1
When 1 disengages from the engaging portion 15, the valve opens.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a liquefied gas drain valve used to discharge liquefied gas leaked from a liquefied gas storage tank to the outside due to damage or the like.

[0002]

[Prior Art]

 When a liquefied gas storage tank is partially damaged and internal liquefied gas leaks from the storage tank, the conventional liquefied gas drain valve for discharging the liquefied gas to the outside has the configuration shown in FIG. There is something.

That is, in the conventional drain valve a for liquefied gas, the valve plate d is separated from the valve seat e against the spring c by the supply of the compressed air b, so that the valve plate d and the valve seat e are separated from each other. The liquefied gas is made to pass through from the inlet side I to the outlet side O, and the compressed air b is supplied from the air compressor f via the solenoid valve g. At the outlet 4 of the gap 2 of the liquefied gas storage tank in which the heat insulating material 3 is arranged outside the gas storage tank body 1, the inlet side I of the drain valve a is connected to the valve inlet pipe h. The liquefied gas b leaked from the inside of the liquefied gas storage tank main body 1 is attached to the valve inlet pipe h from the outlet 4 of the gap 2, and the valve inlet pipe h is A low temperature sensor i is attached. j is a valve extraction pipe, and k is a tray.

When the liquefied gas 1 leaks into the void 2 due to a partial damage of the liquefied gas storage tank body 1 and reaches the valve inlet pipe h from the void 2, the low temperature sensor i is activated and the low temperature is detected. A signal from the detection sensor i is sent to the electromagnetic valve g and the motor M of the air compressor f to operate the air compressor f to supply the compressed air b to the drain valve a through the electromagnetic valve g. As a result, when the valve plate d separates from the valve seat e, the liquefied gas that has entered 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]

[Problems to be solved by the device]

 However, the above-mentioned conventional drain valve for liquefied gas requires a low temperature sensing sensor i for valve operation, a control device such as a solenoid valve g, and a valve driving power device such as an air compressor f and an air pipe. However, there are problems that the equipment is complicated and expensive, that in the case of combustible fluid, explosion-proof measures are required, and it is uneconomical in terms of quality control and quantity.

Therefore, the present invention is to provide a drain valve for liquefied gas that has a simple structure and can be reliably operated without requiring power.

[0007]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention attaches the upper end of a plate bimetal with a stopper attached to the lower end to the upper part in a tubular valve box with a bimetal fixing hardware, and the central part in the valve box. The coil spring retainer for sealing is slidably fitted to the lower end of the rod that is placed parallel to the vertical direction, and the coil spring retainer for valve opening is screwed onto the upper part of the rod so that it can move up and down. A valve plate is attached to the lower end of the rod, and the sealing coil spring retainer is provided with an engaging portion capable of engaging with the stopper, and the sealing coil spring retainer and the valve opening coil spring retainer are connected to each other. A sealing coil spring is interposed between them, and a valve opening coil spring, which is weaker than the sealing coil spring, is interposed between the valve opening coil spring holder and the bimetal fixing hardware. Includes a seal device between the bottom of the box And to configuration.

[0008]

[Action]

 If the low temperature liquefied gas inside leaks into the void due to the damage of the liquefied gas storage tank body, it enters the valve box through the void. This lowers the temperature of the plate bimetal in the valve box and deforms it, so that the stopper at the lower end of the plate bimetal is released and the coil spring for sealing is opened, but at the same time, the rod is pushed down by the coil spring for valve opening. Moves downward, the valve is opened, and the liquefied gas is discharged to the outside of the valve.

[0009]

【Example】

 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. As with the liquefied gas storage tank shown in FIG. 4, a heat insulating material 3 is arranged outside the liquefied gas storage tank body 1. The liquefied gas storage tank main body 1 and the heat insulating material 3 are provided with a space 2 serving as a flow path, and the liquefied gas storage tank for a liquefied gas of the present invention is provided at the position of the outlet 4 of the space 2 in the liquefied gas storage tank. Install the drain valve 5.

The liquefied gas drain valve 5 of the present invention is a cylindrical valve box 7 attached to a valve box attachment piece 6 fixed at the position of the outlet 4 of the gap 2, and is screwed onto an upper part of the valve box 7. And a bimetal fixing hardware 8 having a plurality of valve inlets 9 opened, and a stopper 11 attached to the lower end of the bimetal fixing hardware 8 are arranged in parallel so as to face each other. 8 has a plate bimetal 10, a rod 13 positioned at the center of the valve box 7, and a stopper 11 at the lower end of each plate bimetal 10, and has an engaging part 15 Is fitted to the lower end of the rod 13 so as to engage with the stopper 11, and the coil spring retainer 14 for sealing is screwed to the threaded portion 16 on the upper part of the rod 13 so that So that you can move freely Valve opening 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 the valve opening coil spring holder The coil spring for sealing 19 interposed between the tool 17 and the coil spring holder 14 for sealing, the valve plate 20 detachably screwed to the lower end of the rod 13, the lower end surface of the valve box 7 and the above As shown in FIG. 3, the plate bimetal 10 is made of a low-expansion metal on the outer surface side and a high-expansion metal on the inner surface side. After the two types of metal are bonded together, they are formed by rolling, and the sealing coil spring 19 has a larger spring force than the valve opening coil spring 18.

When the liquefied gas storage tank is normal, the drain valve 5 of the present invention is closed and the flow of N ₂ gas or dry air that fills the space 2 does not occur, and the outer circumference of the storage tank main body 1 is reduced. Since the temperature can be maintained at a low temperature, 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 out into the void 2 as shown in FIG. Pass through 9 and enter inside the valve box 7. When the liquefied gas 22 flows into the valve box 7 and flows down, the temperature inside the valve box 7 is lowered by the liquefied gas 22, so that the temperature of the plate bimetal 10 is also lowered.

Since the plate bimetal 10 has a structure 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 curved outward as shown in FIG. 3 due to the temperature decrease. .. When the stopper 11 at the lower end of the plate bimetal 10 bends from the engaging portion 15 of the sealing coil spring holder 14 to a position where it can be disengaged, the engaging portion 15 of the sealing coil spring holder 14 stops at the stopper 11. Instantly leave. As a result, the sealing coil spring 19 is released and loses its elasticity, and at the same time, the compression amount of the valve opening coil spring 18 is released, the rod 13 is pushed down, the valve plate 20 moves downward, and the valve is opened. Become.

In the above description, the compression amount 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 valve open 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 the liquefied gas 22 leaking into the void 2 is small, it may be vaporized before reaching the valve inlet 9. However, even if the leaked liquefied gas is vaporized, the pressure in the void 2 may be higher than that in the void 2. Also, by selecting the spring force so that the force of the sealing coil spring 19 is small, the internal pressure of the valve box 7 due to the vaporized gas overcomes the sealing coil spring 19 and pushes the valve plate 20 downward, Can be opened.

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

It should be noted that the present invention is not limited to the above-mentioned embodiment, and for example, the case where two plate by-metals 10 are used is shown, but it is also possible to use two or more plates, and other aspects of the present invention. Of course, various changes can be made without departing from the spirit of the invention.

[0020]

[Effect of the device]

 As described above, according to the drain valve for liquefied gas of the present invention, the upper end of the plate bimetal with the stopper attached to the lower end is attached to the upper part in the valve box with the bimetal fixing metal, and the central part in the valve box is attached. The coil spring retainer for sealing, which can be engaged with the stopper, is fitted to the lower end of the rod positioned on the upper side of the rod, and the coil spring retainer for opening the valve can be moved up and down on the upper part of the rod. Attach the coil spring between the valve-opening coil spring holder and the bimetal fixing hardware, and between the valve-opening coil spring holder and the sealing coil spring holder, respectively. Since the valve plate attached to the end and the lower end surface of the valve box can be opened and closed, the following excellent effects can be obtained. (i) It has a simple structure that utilizes the deformation of the plate bimetal and the reaction force of the coil spring, and it can be operated automatically and reliably without requiring power. (ii) By adjusting the width of the engaging part of the coil spring retainer for sealing that engages with the stopper at the lower end of the plate bimetal, the temperature at the time of valve opening can be set, and until the set temperature is reached. The valve plate can be prevented from opening. (iii) By adjusting the compression strengths 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) Since it is possible to easily open and close the valve manually by pulling the valve plate downward, if necessary, it is possible to easily discharge the fluid inside.

[Brief description of drawings]

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

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

FIG. 3 is a cross-sectional view showing a state in which the drain valve for liquefied gas of the present invention is opened.

FIG. 4 is a cross-sectional view showing an implementation state of a conventional liquefied gas drain valve.

[Explanation of symbols]

 1 Liquefied gas storage tank main body 2 Void 3 Heat insulating material 5 Liquefied gas drain valve 7 Valve box 8 Bimetal fixing hardware 10 Plate bimetal 11 Stopper 13 Rod 14 Sealing coil spring retainer 15 Engagement portion 17 Valve opening coil spring retainer 18 Coil spring for valve opening 19 Coil spring for sealing 20 Valve plate 21 Packing (sealing device)

Claims (1)

[Scope of utility model registration request] 1. An upper end of a plate bimetal having a stopper attached to a lower end thereof is attached to an upper part of a tubular valve box with a bimetal fixing hardware, and arranged vertically parallel to a central part of the valve box. A sealing coil spring holder is slidably fitted to the lower end of the rod, a valve opening coil spring holder is screwed on the upper part of the rod so that it can move up and down, and a valve plate is attached to the lower end of the rod. The sealing coil spring holder is provided with an engaging portion that can be engaged with the stopper, and a sealing coil spring is provided between the sealing coil spring holder and the valve opening coil spring holder. A valve opening coil spring, which is weaker than the sealing coil spring, is interposed between the valve opening coil spring holder and the bimetal fixing member, and a sealing device is interposed between the valve plate and the lower end of the valve box. Liquefied gas characterized by Drain valve for use.