JPS61115795A - Prevention of sloshing - Google Patents

Abstract

PURPOSE:To ensure thermal insulation while to prevent sloshing effectively by filling the space between the liquid level in hull tank and the inner face of tank with foaming styrole chips. CONSTITUTION:Foaming styrole chip containing section 3 is arranged through a duct 2 above a tank 1 for containing fluid such as ballast water, LNG, LPG, crude oil, etc. mounted in membrane type hull tank. Then foaming styrole chips 5 are filled through the duct 2 in the upper space of the liquid level in the tank 1. Upon function of sloshing wave, the functioning force is dispersed through collision of said chips 5 thus to reduce the impact functioning against the sidewall of tank. Furthermore, thermal insulation is ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION The present invention relates to a method for preventing sloshing, and aims to provide a simple method that can appropriately prevent sloshing on ships.

Industrial applications Technology to prevent sloshing on ships.

Conventional technology: Ballast water, LN, loaded in a membrane-type hull tank
It is well known that fluid liquids such as G, LPG, or crude oil sway due to the rocking of a ship in waves and cause sloshing, and the impact load caused by such sloshing damages the internal materials of the tank and other parts. Therefore, it seems that some proposals have been made in the past to prevent such sloshing, but mechanical attacks such as using baffles or changing the tank shape are generally used to suppress sloshing. In order to achieve this, the entire upper surface of the ship type is covered with a special member, or the direction of the acting force of the generated sloshing is changed to reduce the impact load and avoid damage.

In some cases, the loading ratio for the tank 10 is limited to 10% or less as shown in A in Figure 3, or 90% or more as shown in Figure B, and stowage is not carried out in the middle area. It is being said.

The problem that the invention seeks to solve.

However, it is clear that the conventional sloshing prevention technology such as T is structurally complicated and is not easy to handle.
There are many disadvantages in terms of tank usage, such as limiting the tank length to less than 90 cm or more than 90 cm.In other words, the inability to adopt a loading ratio of 10 to 90% is extremely serious because the tank usage characteristics should be said to be 20 cm. It is definitely disadvantageous.

In particular, in the tanks of LNG ships, the inside of the tank is
The liquid must be kept at an ultra-low temperature such as °C, and vaporization always occurs at the liquid level, so that the evaporated gas can be discharged outside the tank. It is difficult to prevent sloshing by appropriately adding 71111 to these requirements.

"Structure of the invention" A means to solve a problem.

The present invention was devised after consideration to solve the problems of the conventional products as shown in t. This is a method to prevent sloshing, which is characterized by flashing.

Action.

By filling the space below the liquid level in the tank with small pieces of Styrofoam, the energy of the sloshing waves is dispersed by collisions between the small pieces of Styrofoam, and the [[[[[[[[[

The above Styrofoam functions as a heat insulator under conditions where LNG liquid is stored in the tank, and the gaps between the small pieces effectively discharge vaporized components to the outside of the tank. sloshing prevention is properly achieved.

Note that when the tank is connected to the styrofoam small piece storage part located on the side through a duct opened on the bottom side of the tank, the styrofoam pieces are automatically replenished when the liquid level in the tank falls, and then the liquid level rises. A specific embodiment of the present invention is shown in FIG. 1, in which a duct is installed in the t-section of a tank 1 mounted on a ship's hull to contain LNG or other liquids. A small Styrofoam piece storage section 3 is provided through the duct 2t, and small Styrofoam pieces 5 are filled on all sides of the liquid level in the tank 1 through the duct zt.

When the sloshing force acts on the Styrofoam small pieces 5 filled in this way, the acting force is dispersed as shown by the arrow by the collision between the small pieces 5 as shown in Fig. The impact force acting on the tank side wall 1a becomes extremely small.

As mentioned above, when the liquid level in the tank 1 rises or falls, the small pieces 5 are automatically replenished and collected through the duct 2, and since there are gaps between the small pieces 5, the vaporization does not occur. It is clear that it is easy to drain out of the tank, and that it is also desirable to have an insulating effect on the east side.

"Effects of the Invention" According to the present invention as explained above, it is possible to appropriately prevent sloshing of LNG liquid, ballast water, and other loaded liquids in a ship type when the ship body is rocking, and moreover, The structure of the ship type or the structure of the personnel within the ship type will not be particularly complicated or changed, thereby causing disadvantages in the use of ship inspections, and the filled Styrofoam pieces can be easily handled and automatically replenished or discharged. This invention has great industrial effects, as it can be applied to LNG tanks and the like to obtain desirable characteristics, as it ensures road protection, heat insulation, and discharge of vaporized components from the tank.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and FIG. 1 is a cross-sectional explanatory diagram of ship types showing the essentials of the non-inventive method, and FIG. 2 is an explanatory diagram of the effect of reducing sloshing energy by small pieces of Styrofoam. , FIG. 3 is an explanatory diagram of a conventional sloshing countermeasure method by limiting the number of layers inside a tank.
- However, in these drawings, 1 is a tank, 2 is a duct, 3 is a styrofoam piece storage area, 4 is a liquid level in the tank, and 5 is a styrofoam piece. Patent applicant: Nippon Kokan Co., Ltd. 1st/2nd 1st

Claims (1)

[Claims] A sloshing prevention method characterized by filling the space between the liquid level and the inner surface of the tank in a tank attached to a ship's hull with small pieces of styrofoam.