JPS58482A - Liquid cargo carrier - Google Patents

Abstract

PURPOSE:To prevent the damage by sloshing based upon the movement of fluid within a tank by a structure wherein the four tank corners of the tank of the carrier are formed with curved plates inwardly concaves and as well as the bottom plates of top side tanks are also formed with curved plates inwardly concaved. CONSTITUTION:The tank 1 is formed with the outside platings 2 of the carrier and transversal bulkheads 3. The four tank corners are formed with the curved plate with a radius of curvature R1 of no less than 2,000mm. respectively. In addition, the bottom plates 6 of the top side tanks 5 are formed with the curved plates downwardly concaved with a radius of curvature R2 respectively. Furthermore, the corners met by the transversal bulkheads 3 and an upper deck 7 are formed with curved plates with a radius of curvature R3 of no less than 2,000mm.. Accordingly, the movement of fluid within the tank does not produce any stagnation and the concentration of hydrodynamic energy is relieved, resulting in enabling to dodge the generation of the shock of sloshing.

Description

[Detailed description of the invention] The present invention relates to a liquid cargo carrier.

Liquid cargo carriers are inspected for sloshing (SL) due to the movement of fluid in the tanks due to their agitation.

-ahing) may result in damage to its components.

For example, in the tank top TT, as shown in the partial cross-sectional view of FIG. 1, the liquid level of the fluid in the tank is a.

A standing wave is generated that moves in the order of b, e, and d, and the wave crest hits the tank top TT in the direction of the arrow, causing damage to the area shown by hatching. This type of sloshing is based on a standing wave at a liquid level of 50% or more. In addition, at the tank corner TC of the ship inspection, as shown in the horizontal sectional view in Figure 2 and the tn-tn sectional view in Figure 3, the wave crests WF of the traveling waves of the fluid in the tank are a and b.

Since the tank corner TC moves in the order of C, the part shown by hatching is damaged by the sloshing of standing waves with tank corner TC, and these six types of sloshing are caused by standing waves at liquid levels of 3 (1 or more).

Figures 4 (A) and (B) are respectively Figure 1.

＼ A partially enlarged view of Figure 2 shows that in the conventional hull structure, stagnation points occur in the fluid in the tank and the shock angle β (the angle between the plane perpendicular to the direction of shock wave propagation and the liquid receiving surface) is small. , indicating that the impact pressure becomes large.

Incidentally, the impact pressure p due to sloshing of the bow section is generally expressed by the following formula; p-1-4- .rho.IIv where k: [i impact pressure coefficient .rho.: density .circle.]=impact velocity.

Here, k is known to be a joist with a small impact angle β, as shown in FIG.

Sloshing occurs frequently at tank tops and tank corners, such as when going uphill, due to ice blocks colliding with an extremely small impact angle β and energy concentration at the corners. In order to increase this and reduce the movement of the fluid in the tank itself, extensive reinforcements have been made to the ship's inspection system, resulting in an increase in ship weight.

The present invention has been proposed in view of the above circumstances, and aims to provide a hull that reduces impact pressure by taking into account the characteristics of sloshing, and reduces the overall hull weight. The tank corner is formed by a curved plate concave inward, and the bottom plate of the top side tank is formed by a curved plate concave inward.

An embodiment in which the present invention is applied to a tanker will be explained with reference to the drawings. FIG. 6 is a partial horizontal sectional view of the tanker, and FIG.
8 is a longitudinal sectional view of FIG. 7, FIG. 9 is an explanatory diagram showing the movement of the fluid in the tank in FIG. 7, and FIG. 10 is an explanatory diagram showing the movement of the fluid in the tank in FIG. The explanatory diagram shown in FIG. 11 is a sectional view taken along the line XI-XI of FIG. 1θ.

First, in Figures 6 to 8, l is a tank, 2 is a side shell plate,
3 is a transverse bulkhead, 4 is a hatch cover, 5 is a top side tank, 6 is a bottom plate of the top side tank 5, and 7 is an upper deck.

In such a tanker, as shown in FIG.
The bottom plate 6 of the top side tank 5 is a curved plate concave downward with a radius of curvature R2, and the corner between the transverse bulkhead 3 and the upper deck 7 is 20
It is formed of a curved plate with a radius of curvature R3 of 00 mm or more.

According to such a tank, first, the movement of the fluid in the tank with respect to the bottom plate 6 of the top side tank 5 is as shown in FIG. 9, a and b.

It waves in the order of C and d, and the crest of the wave is as shown by the arrow,
75s and the like traveling along the curved bottom plate 6 are not subjected to sloshing as in the known side tank shown in FIG.

Next, at the tank corner part, as shown in Figures 1O to 11, the wave crest advances in the order of B, b, and e, and stagnation does not occur because it escapes vertically and horizontally along the corner curved plate with radius R1. The sloshing that occurs in the known tank corners shown in Figures 2 and 3 will not occur at the tank corners04 According to the present invention, stagnation will not occur at each corner of the tank as shown in the diagonal top. As a result, the concentration of fluid kinetic energy is alleviated and the generation of large impact force due to sloshing can be avoided.
Against Slussloshing, it is also significantly reduced.

As a result, it is possible to omit the conventional weight increase required to strengthen the hull as a countermeasure against sloshing.For example, in a 60,000 OOT class tanker, the weight of reinforcement material is reduced by approximately 1 OOT per 1 tank. can be achieved.

In short, according to the present invention, when the four tank corners of the ship inspection tank are formed with curved plates that are concave inward, the bottom plate of the top side tank is formed with a curved plate that is concave inward. The present invention is extremely useful industrially because it provides a liquid cargo carrier that reduces weight by combating sloshing.

[Brief explanation of drawings]

Figure 1 is a partial cross-sectional view of a known tanker, and Figure 2 is a partial cross-sectional view of a known tanker.
Horizontal sectional view showing the tank shown in the figure, Figure 3 is from ■-■ in Figure 2.
Figures 4 (A) and (B) are partially enlarged views of Figures 1 and 2, respectively, Figure 5 is a diagram showing the impact pressure coefficient of slodging at the bow, and Figure 6. FIG. 1O is an explanatory diagram showing the movement of the fluid in the tank in FIG. 6, and FIG. 11 is a cross-sectional view taken along the line ■-■ in FIG. ■...Tank, 2...Side shell, 3...Transverse bulkhead, 4...
Hatch cover, 5... Top side tank, 6... Bottom plate of top side tank, 7... Upper deck, R1, R2, R3... Radius of curvature, sub-agent Masaru Tsukamoto, patent attorney (and 1 other person)

Claims (1)

[Claims] A liquid cargo carrier characterized in that four tank corners of a ship inspection are formed with inwardly concave curved plates, and a bottom plate of a top side tank is formed with an inwardly concave curved plate.