JP2000241228A - Level gauge for liquefied gas tank and tank for tank lorry using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately visually confirm the filling state of liquefied gas in real time, in a level gauge for liquefied gas and a tank for tank lorry which uses the level gauge. SOLUTION: A level gauge 4 measures the surface position of liquefied gas in a tank when the gas is injected in the tank 1. This gauge is equipped with an introducing pipe 5 wherein an aperture end part on one end side is inserted from a tank upper part into the inside to be positioned in the vicinity of the bottom surface of the tank, and the other end side is vertically suspended from the upper part of the tank, an U-shaped pipe 6 whose one end is connected with the lower part of the other end of the introducing pipe, and a discharge pipe 7 which is inserted from the upper part of the tank into the inside in such a manner that one end side is connected with the other end side of the U-shaped tube, and an aperture end portion of the other end side is positioned at the upper part in the tank. Antifreeze solution 8 is injected in the U-shaped tube. A glass gauge 9 which can visually confirm the level of the antifreeze solution from the outside is installed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid level gauge for a liquefied gas tank for measuring a liquid level of a liquefied gas in a tank in which a liquefied gas such as LNG is loaded, and a tank lorry tank using the same.

[0002]

2. Description of the Related Art In a tank lorry in which liquefied gas such as LNG is loaded and transported in a tank, when a liquefied gas is injected into the tank, as a means for measuring the injection amount, conventionally, a float type liquid level meter or a static level meter is used. A liquid level gauge such as a capacitance type liquid level gauge is used. These liquid level gauges employ a small analog type indicator.
And so on.

[0003]

However, the above-mentioned conventional liquid level gauge has the following problems. In other words, since the analog indicator is used, the reading accuracy is slightly lower and the response speed is slightly slower, so it is not possible to accurately grasp the liquid level in real time at the time of injection, which often leads to overloading. is there. For this reason, at the present time, at the shipping base, measurement using a truck scale is also performed in order to prevent this overloading. Further, in the above liquid level gauge, since the liquid level of the liquefied gas is once converted into an electric signal and displayed on the analog indicator, the actual filling state of the liquefied gas cannot be directly confirmed with the naked eye. . Further, the above-mentioned liquid level gauges are relatively expensive.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides an inexpensive liquid level gauge for a liquefied gas tank and a tank lorry tank using the same, which can check the filling state of the liquefied gas with the naked eye in real time and accurately. The purpose is to provide.

[0005]

The present invention has the following features to attain the object mentioned above. That is, in the liquid level gauge for a liquefied gas tank according to claim 1, when the liquefied gas is injected into the tank, the liquid level gauge measures the liquid level position of the liquefied gas in the tank, and the open end at one end is the open end. An introduction pipe portion which is inserted into the inside from the tank upper portion so as to be located near the bottom surface in the tank, and the other end side is disposed in a hanging state from the upper portion of the tank to the outside of the tank, and one end portion is provided at the lower end on the other end side of the introduction pipe portion. A connected U-shaped pipe portion, and a discharge pipe inserted into the inside of the tank such that one end is connected to the other end of the U-shaped pipe and the open end of the other end is positioned in the upper portion of the tank. The U-shaped tube section is provided with a glass gauge in which antifreeze is injected into the inside of the U-shaped pipe, and a liquid level of the antifreeze is visible from the outside.

In this liquid level gauge for a liquefied gas tank, an antifreeze is injected into the U-shaped pipe portion and a glass gauge is provided so that the liquid level of the antifreeze can be visually recognized from the outside. The liquefied gas injected into the U-tube section from the opening end of the introduction pipe section into the introduction pipe section is almost the same as the liquid level in the tank, and the gas in the introduction pipe section is pushed by the liquefied gas along with this. Antifreeze moves to the discharge pipe side. That is, since the liquid level of the antifreeze moves according to the amount of the injected liquefied gas, the liquid level of the antifreeze is read by a glass gauge to directly confirm the injection amount of the liquefied gas in real time. it can. In addition,
The liquefied gas has a low temperature, for example, about -160 ° C. in the case of LNG. However, the liquefied gas itself does not directly contact the antifreeze and the measurement liquid is the antifreeze, so that the inside of the U-shaped tube does not freeze.

In the liquid level gauge for a liquefied gas tank according to a second aspect, the liquid level gauge for a liquefied gas tank according to the first aspect is provided.
The U-shaped pipe has a technology in which the inner diameter is set to be larger than that of the introduction pipe.

In this liquid level gauge for a liquefied gas tank, the inside diameter of the U-shaped pipe is set to be larger than that of the introduction pipe, so that the U
The capacity in the tube section is increased, and the glass gauge can be made smaller (shorter).

According to a third aspect of the present invention, there is provided a tank truck for mounting a liquefied gas mounted on a tank lorry vehicle, the technology including the liquid level gauge for a liquefied gas tank according to the first or second aspect. You.

The tank lorry tank is provided with the liquid level gauge for the liquefied gas tank according to claim 1 or 2, so that when the liquefied gas is injected, overloading can be prevented, and the weight of the tank lorry itself can be reduced. Labor such as measurement using

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a liquid level gauge for a liquefied gas tank and a tank lorry tank using the same according to the present invention will be described below with reference to FIGS. In these figures, 1 is a tank for a tank truck, 2 is a tank truck, 3 is LNG, and 4 is a level gauge.

[0012] The tank 1 for a tank truck of the present embodiment.
As shown in FIG. 1, is mounted on a tank lorry vehicle 2 and loaded with LNG (liquefied gas) 3.
As shown in FIG. 3 and FIG. 3, a liquid level meter (liquid level meter for liquefied gas tank) 4 for measuring and displaying the injection amount of LNG 3 is provided. As shown in FIG. 3, the liquid level gauge 4 is inserted from the upper portion of the tank 1 so that the open end 5a on one end is located near the bottom surface in the tank 1, and the other end is connected from the upper portion of the tank 1 to the tank. (1) an introduction pipe portion 5 supported in a hanging state outside;
A U-shaped pipe 6 having one end connected to the lower end of the other end of the introduction pipe 5, and one end connected to the other end of the U-shaped pipe 6 and an open end 7 a at the other end in the tank 1. And a discharge pipe portion 7 inserted from the upper portion of the tank 1 so as to be located at the upper portion of the tank 1.

The U-shaped tube 6 has an antifreeze 8 injected therein, and a glass gauge 9 from which the level of the antifreeze 8 can be visually recognized from the outside. This antifreeze 8
An amount that balances the pressure P (normally 800 mmAq) in the tank 1 is injected in advance, and a coloring liquid is used to improve visibility. 4, the inner diameter 6a of the U-shaped pipe 6 is set to be larger than that of the introduction pipe 5.

Further, in the glass gauge 9, marks are shown at the liquid surface positions of the antifreeze 8 corresponding to the case where the injection amount of the LNG 3 is zero and the case where the amount of LNG 3 is the prescribed load amount, respectively.
The filling condition can be easily judged with the naked eye. The liquid level gauge 4 is fixed to the tank 1 by a support member (not shown) so as to withstand vibration of the moving rank lorry vehicle 2.

Next, a method of measuring the injection amount of LNG using the liquid level meter 4 in the tank truck 1 of the present embodiment will be described.

First, when injecting LNG3 into the tank 1, as shown in FIGS. 1 and 3 (a), the LNG receiving line 10 for injecting LNG3 into the tank 1 and the BOG 12 from the tank 1 at the shipping base. BOG return line 11 is connected to tank 1. Then, when LNG 3 is injected into the tank 1 from the LNG receiving line 10, FIG.
As shown in (b), the LNG 3 flows into the introduction pipe 5 from the opening end 5a of the introduction pipe 5 by an amount that becomes almost the same as the liquid level in the tank 1.

In accordance with this, the BOG 12 in the introduction pipe section 5 pushed by the LNG 3 causes the amount of the LNG 3 close to the inflow of the U-shaped pipe section to be reduced as shown in FIG. 3 (b) and FIG. 4 (b). The liquid level B of the antifreeze liquid 8 in the inside 6 is pushed down, the antifreeze liquid 8 moves to the discharge pipe 7 side, and the liquid level on the glass gauge 9 side rises. That is, the liquid level of the antifreeze 8 moves in accordance with the amount of the injected LNG 3.
The injection amount of G3 can be visually confirmed in real time.

Although the temperature of the LNG 3 is about -160 ° C., the LNG 3 itself does not directly contact the antifreeze liquid 8 and the measurement liquid is the antifreeze liquid 8, so that the inside of the U-tube portion 6 does not freeze. Although the temperature and pressure inside the tank 1 fluctuate slightly due to the injection, it does not significantly affect the measurement of the liquid level gauge 4 and can be regarded as substantially constant.

Although the liquid level gauge of the present embodiment is provided in the tank for the tank truck, it may be used in another tank for the liquefied gas.

[0020]

According to the present invention, the following effects can be obtained. (1) In the liquid level gauge for a liquefied gas tank according to claim 1, U
The antifreeze liquid is injected into the inside of the tube, and a glass gauge is provided so that the liquid level of the antifreeze can be visually recognized from the outside, so that the antifreeze liquid moves according to the amount of the injected liquefied gas. By reading the surface position with a glass gauge, the injection amount of the liquefied gas can be confirmed with the naked eye in real time and accurately. In addition, since the antifreeze does not come into direct contact with the liquefied gas and the measurement liquid is the antifreeze, the inside of the U-shaped tube does not freeze and good measurement is always possible. Therefore, with a simple and inexpensive configuration, it is possible to easily prevent overloading during injection of the liquefied gas.

(2) In the liquid level gauge for a liquefied gas tank according to the second aspect, since the inner diameter of the U-shaped pipe is set to be larger than that of the introduction pipe, the capacity in the U-shaped pipe is increased and the glass gauge is increased. It can be reduced in size and can be easily installed in tank trucks.

(3) Since the tank truck according to the third aspect is provided with the liquid level gauge for the liquefied gas tank according to the first or second aspect, it is possible to prevent overloading when the liquefied gas is injected. In addition, it is possible to save trouble such as measuring the weight of the tank lorry itself, and to improve and simplify the accuracy of the loading operation.

[Brief description of the drawings]

FIG. 1 is a schematic piping diagram showing a line connection at the time of injection in an embodiment of a tank lorry tank according to the present invention.

FIG. 2 is a schematic configuration diagram showing an embodiment of a liquid level gauge for a liquefied gas tank and a tank lorry tank using the same according to the present invention.

FIG. 3 is an explanatory view showing a liquid level gauge for a liquefied gas tank and a tank lorry tank using the same according to an embodiment of the present invention before and after injection.

FIG. 4 is a side view showing a state before and after injection in one embodiment of the liquid level gauge for a liquefied gas tank according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 tank lorry tank 2 tank lorry vehicle 3 LNG 4 liquid level gauge (liquid level gauge for liquefied gas tank) 5 introduction pipe section 5a opening end of introduction pipe section 6 U-shaped pipe section 6a inner diameter of U-shaped pipe section 7 discharge pipe section 7a Open end of discharge pipe 8 Antifreeze 9 Glass gauge

Claims (3)

[Claims] 1. A liquid level gauge (4) for measuring a liquid level position of a liquefied gas in a tank when the liquefied gas (3) is injected into the tank (1), wherein an open end (5a) at one end is provided. Is inserted from the upper part of the tank into the inside so as to be located near the bottom surface in the tank, and the other end is disposed in a hanging state from the upper part of the tank to the outside of the tank; A U-shaped pipe part (6) having one end connected to the lower part, and an open end (7a) connected to one end and the other end of the U-shaped pipe part are located in the upper part of the tank. And a discharge pipe part (7) inserted into the inside from the upper part of the tank so that the antifreeze liquid (8) is injected into the inside of the U-shaped pipe part, and the liquid level of the antifreeze liquid is visible from outside. A liquid level gauge for a liquefied gas tank, comprising a glass gauge (9). 2. The liquid level gauge for a liquefied gas tank according to claim 1, wherein said U-shaped pipe (6) has an inner diameter of said inlet pipe (5).
A liquid level gauge for a liquefied gas tank, which is set to be larger. 3. A liquid level gauge (4) for a liquefied gas tank according to claim 1, wherein the tank is mounted on a tank lorry vehicle (2) and loaded with a liquefied gas (3).
A tank for a tank lorry, comprising: