JPH0212320B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a cylinder having a side plate stiffener, which maintains airtightness between the roof body and the inner surface of the side plate, and floats the upper end of the side plate to a predetermined position by air pressure, and which is connected to the side plate. Regarding shaped tanks.

Conventional technology Cylindrical tanks that store oil, LPG, etc. have huge side areas and are subject to large external forces during storms. To prevent buckling in the circumferential direction, horizontal annular tanks are installed at appropriate intervals on the side plates of the tank. A stiffener called a wind girder is installed. Traditionally, side plate stiffeners for cylindrical tanks have been chevron-shaped, groove-shaped, CT-shaped (cut T-shaped), etc.
Steel sections with cross-sectional shapes such as H-shape, H-shape, or I-shape are generally used. FIG. 1 is a diagram showing an example of the structure of a flat-bottom cylindrical double shell tank, in which an inner tank bottom plate 6 is laid on an outer tank bottom plate 1 with a bottom cooler 9 interposed therebetween. Outer tank side plate 2, inner tank side plate 7 and outer tank roof 5
A cold insulating material 10 is filled between the inner tank roof 8 and the inner tank roof 8. Stiffeners 3 having an L-shaped cross section are provided at appropriate intervals on the inner surface of the outer tank side plate 2. Stiffener 3
Usually, as shown in FIG. 2, it is fixed to the side plate by welding together with ribs 3b arranged at appropriate intervals in the circumferential direction.

In a double shell tank as shown in Fig. 1, the side plate stiffener 3 is attached to the inner surface of the outer tank side plate 2 in order to spray water over the entire outer surface of the outer tanks 2 and 5 for fire prevention and tank cooling. Designed to allow water to flow evenly over the outer surface of the side panels.

By the way, as shown in FIG. 3, the method for installing the roof of a cylindrical tank is as follows: After erecting the side panels 2, the assembled roof 5 is placed on the bottom panel, and a flexible airtight seal 13 is placed around it. A roof floating method in which the roof is floated using air pressure while maintaining airtightness with the inner surface of the side plate 2 to raise the upper end of the side plate 2 to a predetermined position and then fixed to the side plate is advantageous in terms of cost, construction period, etc.

However, when the side plate stiffener 3 is attached to the inner surface of the side plate, in the case of the above-mentioned roof floating method, it is difficult for the roof airtight seal 13 to smoothly slide along the surface, which is extremely dangerous and difficult to perform. It is.
Therefore, when adopting the roof floating method for a cylindrical tank in which side plate stiffeners are installed on the inner surface of the side plate, do not install the side plate stiffener until the roof is floated and fixed to the upper end of the side plate. As shown, the stiffener 11a for temporary construction is mounted on jig 1.
1b and 11c, it is necessary to attach it to the outer surface of the side plate 2, which has the drawback of increasing the amount of work and increasing the number of temporary equipment, leading to higher costs.

In addition, at the stage of removing the stiffeners for temporary work on the outside of the side panels, it was difficult to secure scaffolding for the removal work, and the only option was to use a temporary gondola, etc. to rotate around the outside of the side panels, which was lowered from the roof walkway 12, which was considered dangerous work. There is a need for the development of construction methods that can reduce installation costs and ensure safe work.

For this reason, for example, as shown in Fig. 5 of Utility Application No. 57-52987, stiffeners with a circular triangular shape have been devised, but when actually used, the stiffener shape is different from the conventional type, so it is necessary to adopt it. However, there is a risk of resistance from customers, etc., and there are disadvantages in terms of material arrangement and processing, and there is a need to devise a construction method that incorporates these.

Purpose This invention eliminates the above-mentioned difficulties with the shape and structure of the side plate stiffener of a conventional cylindrical tank, and
It is an object of the present invention to provide a cylindrical tank structure having a side plate stiffener that can meet the above requirements.

Structure The cylindrical tank of the present invention that can achieve this objective has a side plate stiffener installed on the inner surface of the side plate in a horizontal annular shape to prevent buckling of the side plate in the circumferential direction in response to a predetermined external pressure, and a tank roof body. During roof installation work using the floating method, a temporary side plate stiffener cover made of a thin plate with a cross-sectional shape that allows the airtight seal to maintain airtightness with the side plate and smoothly slide upward is placed over the side plate stiffener. It is characterized by being installed in this way.

If a temporary side plate stiffener cover with such a cross-sectional shape is used, the original side plate stiffener can be installed on the inner surface of the side plate before the roof is floated even when the roof is installed using the floating method, so the temporary side plate stiffener cover can be installed on the outer surface of the side plate. It is no longer necessary to use side plate stiffeners, reducing the need for temporary construction and removal work.In addition, the installation and removal of temporary covers on the inner surface of the side plates are done in parallel with the construction process order, and are used for installing the outer tank side plate stiffeners. By attaching the above-mentioned cover on the scaffolding used to install the inner tank side plate and removing it using the scaffolding used when installing the inner tank side plate, a safe work platform can be secured. The installation work can be simplified using adhesive tape (gum tape, etc.), which is effective in reducing costs and shortening the construction period.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

FIG. 6 is a sectional view showing the state of the cylindrical tank according to the embodiment of the present invention during the roof floating process. In this embodiment, the temporary side plate stiffener cover 4 has a trapezoidal cross section, and as shown in detail in FIG. It is adhesively fixed by adhesive tape 4a or the like. Therefore, the lower surface of the temporary cover 4 slopes upward from the attachment edge to the side plate 2 toward the top surface of the stiffener, passes through the vertical top surface, and then slopes downward toward the side plate at the upper surface. ing. Therefore, even if the side plate stiffeners are installed prior to the roof floating process, when the roof body 5 floats, the outer edge of the roof airtight seal 13 made of a flexible material, as shown in FIG. When passing through the stiffener 3 section, use the temporary stiffener cover 4.
It can be easily deformed to follow the shape of , and can be slid upward while maintaining airtightness.

In the above embodiment, in order to improve the slidability of the airtight seal member with respect to the temporary stiffener cover 4, its cross section was made into a trapezoid with the short bottom facing toward the center of the tank. Depending on the degree of flexibility, it is possible to use temporary stiffener covers with various similar cross-sectional shapes, taking into consideration the overhang height, slope of the upper and lower surfaces, width, thickness, dimensions, etc. Needless to say, since the temporary stiffener cover has a sliding effect with the airtight seal, the above-mentioned permanent stiffener shape can be made of conventionally used general purpose steel sections.

Effects As described above, according to the present invention, reinforcement with stiffeners can be performed at the same time as side panel construction, improving safety, and eliminating the need for temporary stiffeners to be attached to the outside surface, reducing the associated temporary construction and removal work. Since it is no longer necessary and the structure can remain in the same shape as the conventional stiffener, there is no problem in adopting it, and the installation and removal of the temporary stiffener cover can be done at the same time as using the construction scaffolding in accordance with the construction process. Furthermore, since the installation and removal of the thin plate cover can be simplified, it is possible to reduce the number of on-site man-hours and reduce costs by shortening the process.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing an example of the general configuration of a general flat-bottomed cylindrical double shell tank, Fig. 2 is a perspective view showing details of the mounting structure of the side plate stiffener on the inner surface of the side plate, and Fig. 3 is a known known structure. 4 is a perspective view showing details of the temporary stiffener mounting structure in that case, FIG. 5 is a sectional view showing an example of a conventional stiffener, and FIG. 6 is a structure of the present invention. 7 is a perspective view showing details of the mounting structure of the stiffener and the temporary stiffener cover, and FIG. 8 is a contact state of the roof airtight seal when the roof is floating with respect to the side plate stiffener of the present invention. It is a perspective view showing an example. 1, 6... Bottom plate, 2, 7... Side plate, 3... Side plate stiffener, 4... Temporary side plate stiffener cover,
5, 8... Roof, 9... Bottom cold insulating material, 10... Roof, side cold insulating material, 11... Temporary construction side plate stiffener, 12... Roof circumference walkway, 13... Roof airtight seal.

Claims (1)

[Claims] 1. A flexible airtight seal member provided around the roof of the tank allows it to slide between the inner surface of the tank side plate and maintain an airtight seal, and the upper end of the side plate is raised to a predetermined position using air pressure, and then In the cylindrical tank that is connected to the tank, a stiffener is provided horizontally in an annular shape on the inner surface of the side plate to prevent buckling of the side plate in the circumferential direction in response to a predetermined external pressure, and
A cylindrical tank characterized in that a temporary stiffener cover having a cross-sectional shape that allows the airtight seal to maintain airtightness and smoothly slide upwardly when the roof body floats is attached to cover the stiffener.