JPH0439514Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to a roof structure for effectively operating the detonation function of a tank that stores flammable hazardous substances such as petroleum (prior art) Sealed tanks that store flammable hazardous materials such as petroleum are usually equipped with a venting device such as a vent pipe to cope with changes in outside temperature and internal pressure fluctuations caused by loading and unloading of stored materials. In addition, in order to prevent damage to storage tanks due to abnormal pressurization due to neighboring fires or internal tank fires, and secondary disasters due to the resulting leakage of hazardous substances, an explosion structure is generally adopted.

That is, as shown in Fig. 6, a top reinforcing member made of a ring-shaped angle material is provided on the upper edge of the side plate, and the top reinforcing member and the roof plate are attached by fillet welding. .

In addition, the roof frame and the top reinforcing member are the same as the roof frame.
The roof plates are welded or screwed together via roof frame attachment pieces provided at the edges of the roof frame, and the roof plates are placed inscribed on the roof frame. In other words, as the pressure inside the storage tank increases, the roof plate bulges, and the top reinforcing member deforms and buckles due to the deformation of the roof plate. The welded joint part of the welded roof plate is broken, and the pressure is released from the broken part to the outside of the storage tank. In other words, due to the abnormally increased pressure inside the storage tank, part or all of the roof is destroyed faster than the bottom plate and side panels storing the flammable hazardous material, thereby releasing the pressure inside the storage tank and destroying the flammable hazardous material. It is designed to prevent the outflow of water and prevent secondary disasters from occurring.

(Problems to be solved by the invention) In the conventional explosion structure, the joint between the side part and the roof part needs to be formed into a weak structure compared to the strength of the side plate part and the bottom plate part. The top reinforcing material deforms and buckles faster than the side and bottom plates.
The deformation buckling requires the fillet weld joining the roof shingle and the top reinforcement to fail open.

On the other hand, the top reinforcing material must be made strong so that it does not buckle easily even when subjected to external loads such as roof loads and snow accumulation, and must also be airtight to seal out the vapors of potentially dangerous substances inside the tank. It also needs to be structured. In other words, in order to enhance the detonation function, it is necessary to weaken the joints between the sides and the roof, and for airtight structures and external loads, the joints between the sides and the roof must be made strong. There are certain needs that must be met, and there are problems that must be met at the same time.

(Means for solving the problem) In a cylindrical tank with a closed structure for storing combustible hazardous materials, the roof panels are divided radially around the apex of the conical roof section, and both ends of the divided roof panels are separated. The flare is bent in an arc shape and has a circular arc part and a straight part connected to the circular arc part, and a sharp concave part is formed in the straight part of the flare, so that the flare of one roof sheet and the other roof sheet adjacent to it are formed. It is an object of the present invention to provide a detonation structure for a hazardous materials storage tank, which has a detonation structure in which the end faces of base metals are brought into contact and joined by edge welding or fillet welding, and which solves the above-mentioned problems.

(Function) When an abnormal pressure increase occurs in the tank, the flared part of the roof plate is first stretched and expanded by the pressure inside the tank, inducing stress concentration in the recessed part of the flare, creating a rupture starting point. Then, the fracture starting point acts as a trigger to extend the fractured portion and open the roof panel portion. The abnormally increased internal pressure of the tank is released from the opening to the outside.

(Example) An example of this invention will be described in detail based on the drawings. FIG. 1 is an overall perspective view of a dangerous goods tank having an explosion structure according to this invention. In the figure, the side panels, the bottom plate, the roof, the top reinforcement members,
is a flared portion, and is a concave portion of the flared portion. The storage tank is shaped like a flat bottom cylinder with a fixed roof. That is, a side plate formed into a concentric cylindrical body is provided in an upright manner on a bottom plate shaped like a circular flat plate, and the contact edges of the bottom plate and the side plate are joined by welding. In addition, on the upper edge of the side plate, a shaped steel such as an angle material is formed into a ring shape, one edge is in contact with the side plate and welded, and the other edge is oriented radially inward or outward of the side plate. A top reinforcing member is provided and formed. The roof is provided by placing the opening edge of a fan-shaped roof plate on the top reinforcing member, and the top reinforcing member and the roof plate are joined by welding to form a storage tank in a sealed shape. The roof is formed by dividing a roof plate into radial sections having an apex angle centered at the apex of the roof, and welding one of the divided roof plates to another adjacent roof plate. In this case, the edges on both sides that sandwich the apex angle of the radially divided roof panels are bent into an arc shape as shown in Figures 1, 2, and 3, forming a flare that connects the straight part and the arc part. The flares are formed by bringing the direct portions of the flares into contact with each other and welding them together. As shown in Figure 3, the abutting part of the flare is made by providing a step on the end face of the flare with a difference in height between the straight part of one roof plate and the straight part of the adjacent other roof plate, and joining them by fillet welding. Alternatively, the flare end surfaces may be formed on the same surface as shown in FIG. 2, and the two may be joined by edge welding.
Furthermore, as shown in FIGS. 4 and 5, a recess formed by cutting off a smooth arc or a recess formed by cutting at a sharp angle is provided at one or more places of the straight line portion formed on the flare of the roof board, As shown in FIG. 4, the recessed portion may be formed so that the end faces completely coincide with each other, or as shown in FIG. It may be joined by welding. The outer opening edge of the conical roof, which is formed by forming roof sheets into a flared shape and welding them, is joined by fillet welding on the top reinforcing member, and the edge of the flared portion of the roof sheet is joined by fillet welding or welding. Weld the backing plate to form a sealed shape.

(Effects) According to this invention, since a recess is formed in the welded joint part of the roof, if an abnormal pressure rise occurs in the tank, stress concentration will occur in the recess, forming a starting point for rupture. The opening of the part can be easily done. In addition, since the roof part is joined by connecting the flare parts, it is possible to provide a roof structure for a dangerous goods tank that has a highly effective detonation function that allows for quick sensing of internal pressure and the opening of the roof part at an early stage. It becomes possible.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of a tank having a roof structure according to this invention, FIG. 2 is an enlarged sectional view taken along line A-A in FIG. 1, and FIG. 3 is an explanatory cross-sectional view of a flared portion showing another embodiment. Figure 4 is an enlarged BB view of the part in Figure 1, Figure 5 is an explanatory diagram of the recess showing another embodiment, and Figure 6 is an enlarged view of the conventional example with part removed. It is an explanatory diagram. 1... Side plate, 2... Bottom plate, 3... Roof, 4...
Top reinforcing member, 5...roof plate, 6...flare part, 7...recessed part.

Claims (1)

[Scope of utility model registration request] In a cylindrical tank with a sealed structure for storing combustible hazardous materials, the roof is divided and the edges of the divided roof sheets are bent into an arc to form a flare that has an arc section and a straight section connected to the arc section. , A risk having an explosion function characterized in that the flare is formed by providing a recess in the straight part of the flare, and the flare of one roof plate is brought into contact with the flare of another adjacent roof plate and joined by welding to form a roof. Roof structure of storage tank.