JPS6114958Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tank safety device for a tanker in which each cargo oil tank is equipped with a liquid sealing device.

When lifting cargo oil from a tanker's cargo oil tank, a cargo oil pump installed on the tanker is used to send the cargo oil to the onshore tank.In order to prevent accidents such as explosions, there are Inject inert gas,
When loading oil into cargo oil tanks, the oil is injected into each tank from a land-based oil pump, but at the same time, a mixture of gas (oil vapor of inert gas and crude oil ) is released into the atmosphere. Furthermore, during voyage, there is a risk of damage to the tank due to pressure fluctuations caused by the shaking of the tanker due to waves or changes in ambient temperature, so a breather valve is installed to provide a breathing effect. There is.

There are a collective vent pipe method and an independent vent pipe method as methods in which such a vent line is installed above the cargo oil tank and an inert gas line is also installed in order to fill the cargo oil tank with inert gas. The former is, as shown in Figure 1,
Loading and unloading oil pipes 3 with branched bell mouths 2 are arranged at the bottoms of the cargo oil tanks 1a, 1b...
A vent/inert gas main pipe 4 is installed on the upper deck of..., and the end of the pipe is connected to a vent post 6 via a vent line main valve 5, and a pipe branched from in front of the vent line main valve 5 is connected through a breather valve 7. At the same time, branch pipes 8a, 8b... are branched from the main vent/inert gas pipe 4 and connected to each oil tank small hatch 10 via stop valves 9a, 9b..., respectively. . Also, the latter is
As shown in Fig. 4, at the bottom of the cargo oil tanks 1a, 1b... there are a cargo oil pipe 3, a bell mouth 2, and a bell mouth 2, similar to the former.
An inert gas main pipe 11 is installed on the upper deck of the cargo oil tank, and gas branch pipes 12a, 12b... are branched off, and a small cargo oil tank hatch equipped with a breather valve 14 is connected via stop valves 13a, 13b... 10, and each cargo oil tank 1a, 1b, . . . is equipped with a high-speed vent valve 15, respectively.

By the way, in the former type of collective vent pipe system, the opening and closing of the valves differ depending on the state of the oil pipe for loading and unloading, and during loading as shown in Fig. 1, the vent line main valve 5 and each stop valve 9a, 9b... When unloading as shown in Fig. 2, each stop valve 9a, 9b... should be opened and the main valve 5 should be closed, and during voyage as shown in Fig. 3, it is necessary to do the same as when discharging cargo. . On the other hand, in the independent vent pipe system, each stop valve 13a, 13b... is closed during loading as shown in Fig. 4.
The high-speed vent valve 15 of the unfilled cargo oil tank 1a opens,
The high-speed vent valve 15 of the filling tank 1b is closed. In addition, during unloading as shown in FIG. 5, all the high-speed vent valves 15 are closed and each stop valve 13a, 13b... is opened, and during sailing as shown in FIG. 6, each stop valve 13a, 1
3b... remains closed, and opens the high-speed vent valve 15 of the cargo oil tank 1a, and then opens the high-speed vent valve 15 of the cargo oil tank 1b.
Both systems require crew members to operate based on their judgment of the situation.

As is clear from the above explanation, unloading of cargo oil,
During loading, each tank is equipped with a safety device that is operated by the crew in order to prevent the tank from exploding or being damaged due to overpressure or underpressure within the tank. It has also been proposed that the inert gas line be equipped with a common safety device for each oil tank, but in this case as well, each oil tank and safety device communicate with each other via a stop valve, so crew members cannot operate the gas line. is absolutely necessary. As described above, conventional safety devices not only have to take into account malfunctions, but also have the possibility of crew members operating them incorrectly or forgetting to operate them, so they are not always perfect.

Furthermore, when a tanker is sailing, pressure fluctuations occur in the oil tank due to vibrations caused by waves and fluctuations in ambient temperature, so a breather valve is installed to allow breathing, but failure of this valve must also be taken into consideration. It is causing damage.

In order to solve the above-mentioned conventional problems, this invention is equipped with a liquid seal device that operates independently and automatically in each cargo oil tank, thereby preventing crew malfunctions or malfunctions of various valves, etc. Nevertheless, the purpose is to prevent damage due to pressure fluctuations within the cargo oil tank, as well as to prevent secondary accidents (for example, marine pollution, etc.) caused by damage to the cargo oil tank.

In order to achieve the above-mentioned purpose, the tanker tank safety device according to the present invention connects the vent line or the vent pipe and the inert gas line to each cargo oil tank via a branch pipe equipped with a stop valve. A liquid sealing device comprising: a liquid cylinder that does not reach the bottom inside the main body; the other end protrudes outside the main body; this protruding portion is covered with a broken cap; and liquid is injected into the main body. are provided respectively, and the inside of the main body of the liquid sealing device and the inside of the cargo oil tank are communicated with each other. The present invention will be explained below with reference to the drawings.

FIG. 7 is a block diagram of an embodiment of the present invention. First of all,
First, the structure and operation of the liquid sealing device 20, which constitutes the essential part of the present invention, will be explained with reference to FIG. Liquid sealing device 2
0 communicates the main body 16 of the device with the cargo oil tank 1a via the top wave of the cargo oil tank 1a, and has a liquid cylinder 17 that does not reach the bottom of the device main body 16 upright, with the other end protruding outside the main body. The projecting portion is covered with a cap 18, and a liquid 19 is injected into the device main body 16. When the inside of the cargo oil tank 1a is overpressurized, the liquid rises in the liquid cylinder 17 as shown in figure a, and the amount exceeding the pressure determined by the liquid specific gravity, water head, and liquid area ratio inside and outside the liquid cylinder is dissipated into the atmosphere. When there is an overpressure in the cargo oil tank 1a, air is sucked in as shown in Figure b. Note that the liquid 19 is selected in consideration of reaction with liquid oil, volatility, antifreeze property, etc.

The present invention provides the above-mentioned liquid sealing device 20 to each cargo oil tank 1.
These are attached to the top plates of a, 1b..., respectively,
If the cargo oil tank 1a, 1b... equipped with this is equipped with a collective vent pipe type vent/inert line as shown in Figure 7, all valves may malfunction during loading as shown in Figure 7. When the cargo oil tanks 1a, 1b, etc. do not function properly, the liquid 19 in the liquid sealing device 20 overflows and the air-fuel mixture in the tanks is released directly to the atmosphere, which causes the cargo oil tanks 1a, 1b, . . . to become overpressure.
1b... is prevented from being damaged. Furthermore, during unloading, if the main valve 5 is damaged but the stop valves 9a, 9b, etc. are closed, the pressure inside the tank will become negative. , the liquid 19 of the liquid sealing device 20 is sucked into the tank to prevent damage to the cargo oil tanks 1a, 1b, . . . Furthermore, even if each valve loses its function during navigation, as shown in FIG. 9, it is safe because the liquid sealing device 20 continues to breathe.

When this invention is applied to an independent vent pipe system,
For example, as shown in FIG.
While the stop valve 13a of a remains closed, the breather valve 14,
Even if the high-speed vent valve 15 is destroyed, the cargo oil tank 1a
The liquid sealing device 20 works effectively, and even if the stop valve 13b and the high-speed vent valve 15 of the cargo oil tank 1b are closed and the breather valve 14 loses its function, it is equally safe. Furthermore, as shown in Fig. 11, even if the stop valves 13a, 13b and vent valve 15 are closed during unloading, or even if all valves are closed or have lost their functions as shown in Fig. 12, even if the valves are closed or have lost their functions, as shown in Fig. It is safe because it never stops.

As is clear from the above explanation, according to the present invention, even if an accident occurs such as closing the stop valve by mistake or loss of function due to malfunction, etc., the cargo oil tank will not be destroyed. Since it is safe, its implementation is highly effective.

[Brief description of the drawings]

Figures 1, 2, and 3 are explanatory diagrams showing the functions of conventional collective vent pipe type vent/inert lines during loading, unloading, and navigation, and Figures 4, 5, and 6 are Similarly, independent vent pipe type vent/
Figures 7, 8, and 9 are explanatory diagrams showing the loading, unloading, and voyage functions of an inert line when the present invention is applied to a collective vent pipe line. Explanatory diagram showing the action, No. 10
Figures 11 and 12 are explanatory diagrams showing loading, unloading, and voyage operations when the present invention is applied to an independent vent pipe line, and Figures 13a and 13b show the main parts of the present invention. It is an explanatory view of an example of a liquid sealing device. 1a, 1b...Loading oil tank, 4...Vent/inert gas main pipe, 5...Vent line main valve, 7...Breather valve, 9a, 9b, 13a, 13b...Stop valve, 11...Inert gas main pipe, 14... ... Breather valve, 15 ... High speed vent valve, 16 ... Device main body, 17 ... Liquid cylinder, 19 ... Liquid, 20 ... Liquid sealing device.

Claims (1)

[Scope of utility model registration request] The vent line or vent pipe and inert gas line are connected to each oil tank via a branch pipe equipped with a stop valve, and a liquid cylinder that does not reach the bottom is installed inside the main body at the top of each oil tank, and the other end is connected to the inert gas line. A liquid sealing device is provided in which the projecting portion is protruded from the main body, the projecting portion is covered with a cap, and a liquid is injected into the main body, and the inside of the main body of the liquid sealing device and the cargo oil tank are communicated with each other. A tank safety device for a tanker characterized by: