JPS5993685A - Floating roof type tank - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a floating roof tank used as, for example, an oil tank.

One type of oil tank is equipped with a floating roof to prevent vapors from escaping the contents. There is an existing invention of a tank having a structure in which a plurality of needle bases made of a flexible membrane are provided at the lower part of the floating roof, and a liquid different from the liquid to be poured into the tank body is poured into the needle bases (the present inventors Already filed Patent Application No. 185830 (dated November 18, 1981)
A floating roof storage tank that can store different types of liquids at the same time).

The essential feature of the above-mentioned invention is that, under normal conditions, the plurality of needle bases made of flexible membranes are arranged so as to receive substantially symmetrical buoyancy with respect to the center point of the floating roof, regardless of the presence or absence of liquid in the needle bases. It is to be. In other words, the entire floating roof is adjusted so that it does not tilt or sag from the horizontal plane.

FIG. 1 shows a structure that is the most practical to manufacture in the above-mentioned existing invention because the shape of the flexible membrane does not have a curved surface. The shape of the flexible membrane (1) is a long rectangular parallelepiped with a square cross section diagonally divided along a plane that includes the diagonal of the square (shown in Figure 1 (al)).The flexible membrane (1) and the floating roof The space surrounded by the lower deck plate (3) and the partition plate (2) lowered downward from the lower deck plate is the needle base (5) on the lower surface of the floating roof (shown in Figure 1 (bl). A plurality of needle bases (5) are arranged ξ symmetrically with respect to the center line of the floating roof (circular).

(Figure 1 (0, (shown in (')). Figure 1 (1))
The dotted line labeled (1) indicates the position of the flexible membrane when the needle base is empty and when it is full. Although not shown, the liquid is injected and discharged into the needle base through the space of the floating roof double deck (4) or directly below the lower deck. A broken deck post is also installed as usual, but it is not shown.

What should be considered with the above-mentioned already invented product is that if a problem occurs in the piping system and the liquid level in the needle base group becomes uneven, the buoyancy force acting on the floating roof becomes uneven and a large deflection force is applied to the floating roof. This is a design consideration. In the example of FIG. 1, it is sufficient to assume that liquid enters only the needle hubs at both ends. At this time, both ends of the floating roof are lifted up, and if the strength is insufficient, there is a risk that the inside of the floating roof will break at some point. However, sufficient reinforcement is required, but the cost is high.

By arranging the needle base as shown in Figure 1, the flexible membrane and partition plate can be expected to suppress sloshing in the direction perpendicular to the longitudinal direction of the needle base during an earthquake. However, against sloshing in the parallel direction, the sloshing suppressing effect of a flexible membrane or partition plate cannot be expected, especially when the needle base is empty.

In view of the above, the present invention was developed to solve these problems. The present invention will be explained in detail below with reference to the illustrative drawings, but the present invention is in no way limited to these examples.

FIG. 2 shows the structure of the main part of this invention. Flexible membrane (1)
, and the basic structure of the needle base (5) are the same as in FIG. In Figure 2, first, the circular shape of the floating roof is divided into four blocks divided by two center lines, and a needle base is provided for each block. The longitudinal direction of the needle base provided in each block shall be orthogonal to the longitudinal direction of the needle base provided in the blocks adjacent to the left and right sides. Naturally, under normal conditions, the buoyancy force exerted on each block is symmetrical with respect to the center point of the floating roof, regardless of the presence or absence of liquid at the needle base. Piping and deck posts are not shown as in Figure 1.

The features of the nine products of the present invention shown in FIG. 2 are as follows. First, in the conventional product shown in Fig. 1, the needle hubs were arranged parallel to each other in only one direction, which was structurally disadvantageous to the bending force perpendicular to that direction. Since the needle hubs are arranged perpendicularly in two directions, it is structurally advantageous against deflection forces in any direction.

In addition, in the previously invented product shown in Figure 1, the needle bases were arranged parallel to each other in only one direction, so when the needle base was low in liquid or empty, the membrane was flexible against sloshing parallel to that direction. However, in the product of the present invention shown in Fig. 2, the needle bases are arranged orthogonally in two directions, so the flexible membrane and partition plate have a suppressing effect against sloshing in any direction. can be expected.

In the present invention, the flexible membrane below the lower deck board of the floating roof can be provided as exemplified in FIGS. 6-1, (b) and (C).

As described above, the present invention provides a floating roof type tank that can store a plurality of different types of liquids, is strong against overall deflection due to uneven buoyancy applied to the floating roof, and is effective in suppressing sloshing in all directions. Is it possible to get something?

[Brief explanation of the drawing]

Figure 1 is a diagram explaining the floating roof tank invented earlier.
Figure (a) is a perspective view of the flexible membrane that forms the needle base on the lower side of the floating roof, and Figure tb) is a perspective view explaining the needle base on the lower side of the floating roof (Figure tc) taken from the A-A cross section side. Figure (C1 is a view of the floating roof viewed from below, Figure (d) is Figure tc) is a BBt sectional view, Figure 2 is a diagram illustrating the floating roof type tank of the present invention, and Figure (C1 is a view of the floating roof viewed from below. al is a view of the floating roof seen from below;
, (bl, (C1) respectively exemplify the arrangement of the flexible membrane below the lower deck board of the floating roof in the floating roof type tank of the invention, which was previously invented. (1)... Flexible membrane (semi-cuboid type), (2)... Partition plate, (3)... Floating roof lower deck plate, (4)... Floating roof (double deck), (5)... Needle base Agent Patent attorney Masashio Yoshitake 2 Figure (a) B. -) F 3 Figure (a) (b) (c) Continued from page 1 ■Applicant Ishii Iron Works Co., Ltd. Ginza, Chuo-ku, Tokyo 4-2-11

Claims (1)

[Claims] (1) It has a double-decker floating roof, and is provided with a partition plate lowered from the floating roof lower deck plate and a flexible membrane below the floating roof lower deck plate, so that the floating roof lower deck plate and the partition plate are In a tank having a slender and variable volume needle base group surrounded by a flexible membrane, the needle base groups are arranged in each block, which divides the floating roof into four equal blocks, but the arrangement of each block is as follows: A floating roof tank characterized in that the longitudinal direction of the needle base is orthogonal to the longitudinal direction of the needle bases of adjacent blocks.