JPS5831837Y2 - Rapture hatch - Google Patents

Description

[Detailed description of the invention] This invention relates to a love hatch that, when an explosion occurs in an offshore crude oil storage tank, etc., the lid easily blows off and releases the internal pressure, thereby minimizing disasters. It is something.

Conventionally, as shown in FIG. 3A, a thin end plate 15 having a partially spherical shape is welded 16 at the periphery with the top facing down inside the hatch coaming 12 provided on the deck 11 of the tank. The normal increase in tank internal pressure due to changes is absorbed by the elastic deformation of the end plate 15, and when the tank internal pressure suddenly increases due to an explosion, etc., the top side of the end plate 15 flips upward, causing the peripheral edge to buckle and prevent welding. There is one in which the part 16 is destroyed.

As an improvement, a thin donut-shaped frame plate 13 whose inner circumferential side is inclined downward is provided inside the hatch coaming 12 as shown in FIG. There are some welded.

However, although there are differences in degree, in all of them, only the center portion including the top part bends upward as the internal pressure of the tank rises to a certain extent, and the pressure on the peripheral edge is reduced due to the rigidity of the hatch combing 12. If pressure is applied, it will be restrained in the in-plane direction and will not buckle easily, and furthermore, the end plate may not blow off unless the pressure reaches about 10 times the initial pressure.

The present invention attempts to propose a love hatch in which buckling occurs at the periphery at the same time when the end plate is reversed, and the welded part is easily destroyed.This will be explained below based on the illustrative drawings of the embodiment.

1 and 2, 1 is a deck of an offshore crude oil storage tank, 2 is a cylindrical hatch coaming provided on the deck 1, and inside the hatch coaming 2 is a donut-shaped rigid structure in the circumferential direction. A thick flange plate 3 having a diameter is firmly welded 4.

Reference numeral 5 denotes a thin elastic head plate curved into a partially spherical shape, and its peripheral edge is lightly fillet welded 6 to the inner peripheral edge of the upper surface of the flange plate 3 with the top facing downward.

In the above configuration, normal pressure fluctuations within the tank are absorbed by the elastic deformation of the head plate 5, but when the pressure suddenly increases to a certain level or higher, the top of the head plate 5 is turned upward.

In this case, since the flange plate 3 is rigid and thick, it is not affected by internal pressure, and the end plate 5 is only fillet welded 6 to the inner periphery of the upper surface of the flange plate 3 at the periphery, so that almost no line is formed. Since it is welded and the adhesion force is weak, the entire end plate 5 is reversed without being constrained in the in-plane direction, and the film stress after the inversion is concentrated on the welded part 6, which easily breaks and the end plate 5 is blown off.

According to the Love Chart hatch of the present invention, as explained above, when the pressure inside the tank suddenly rises above a predetermined pressure, the entire head plate turns its top upward, bending stress concentrates on the periphery of the head plate, and the welded part is damaged. Because it breaks easily, the end plate is blown away, releasing internal pressure and minimizing disasters.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view showing an embodiment of the present invention;
The figure is a sectional view of FIG. 1, and FIGS. 3A and 3B are sectional views of the conventional example. 2... Hatch coaming, 3... Flange plate, 5... End plate, 6... Welded part.

Claims (1)

[Scope of utility model registration request] A thick, rigid flange plate is provided in the inner circumferential direction of the hatch coaming of the tank, and a thin, partially spherical end plate is fillet-welded at the peripheral edge to the inner periphery of the upper surface of the flange plate, with the top facing downward. Love Charhat.