JP3022356U - FRP double shell tank cylinder - Google Patents

Abstract

(57) [Summary] (Correction) [PROBLEMS] To provide a cylindrical portion of a FRP double-shell tank having improved productivity and excellent economical efficiency. SOLUTION: A reinforced plastic inner shell 5, a reinforced plastic outer shell 7, a reinforcing rib 8 on the periphery of the reinforced plastic outer shell 7, and a reinforced plastic inner shell 5 and an outer shell 7 are provided. The thermoplastic sheet 1 is provided, and the reinforced plastic outer shell 7 and the film 6 provided between the sheet 1 are provided, and the thermoplastic sheet 1 is provided on the outer periphery of the inner shell 5. It has a curvature along it and irregularities on its surface.

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

 The present invention relates to an FRP double shell tank, and more particularly to an FRP double shell tank used as a gasoline tank for underground burial.

[0002]

[Prior art]

 Conventionally, underground storage tanks made of steel sheet have been used as underground underground gasoline tanks. The steel tank is made of steel sheet with a thickness of 3.2 mm or more, and has an outer surface coated to prevent corrosion.

However, such a steel tank is used by being buried underground for a long time due to its nature, and cannot completely prevent corrosion of a steel sheet due to corrosion due to acid soil and electric corrosion. Pinholes have occurred in the tank, and dangerous substances inside the tank, such as gasoline, have leaked.

[0004] Therefore, conventionally, anticorrosion measures for preventing corrosion of the outer surface of the underground storage tank have been strengthened. Due to the characteristics of steel sheets, it is difficult to completely prevent corrosion, so reinforced plastics (FRP), which have excellent corrosion resistance and are sufficiently usable in terms of strength, are drawing attention.

In July 1993, the “Ordinance on the Regulation of Dangerous Goods (Ordinance No. 268, 1993)” was partially revised, and the underground storage tank made of steel plate was covered with FRP so as to have a gap. In addition, the use of steel reinforced plastic double-shell tanks (hereinafter referred to as "SF double-shell tanks") equipped with equipment for detecting leaks of dangerous substances is now permitted, and SF is now available. The use of double shell tanks is the mainstream.

Although the SF double shell tank is more resistant to corrosion by acidic soil and electrical corrosion than the steel tank, it still has sufficient corrosion resistance because pinholes are generated due to corrosion after many years of use. Is not considered to have.

Furthermore, in February 1995, the “Ordinance on the Control of Dangerous Goods (Ordinance No. 15 of 1995)” was partially revised so that the underground storage tanks made of FRP will have a gap between them. The use of FRP double-shell tanks, which are coated and equipped with equipment to detect dangerous substances, has been approved.

The FRP double-shell tank is lighter in weight and more durable than the SF double-shell tank.

[0009]

[Problems to be solved by the device]

 However, the material cost of FRP, which is the material of FRP double shell tank, is higher than that of steel material, and productivity is low because it is difficult to provide a gap for detecting leakage of dangerous substances inside the tank. The current situation is that it is difficult to realize this in the market.

Therefore, in order to replace the SF double shell tank, which is currently the mainstream in the market, with the FRP double shell tank, the FRP double shell tank is manufactured at the same price as the SF double shell tank. There is a need.

Therefore, an object of the present invention is to provide an FRP double-shell tank cylindrical portion that improves productivity and is excellent in economic efficiency. Here, the cylindrical portion of the FRP double-shell tank is integrated with the underground storage and the FRP (outer shell) coated on the underground storage tank, and is “dangerous” against the load used for the FRP double-shell tank. It has a safe structure as stipulated in the "Regulations Concerning Articles (Ordinance of the Ministry of Home Affairs No. 2 of 1995)".

[0012]

Means for Solving the Problems An FRP double shell tank according to the present invention comprises an FRP inner shell, an FRP outer shell, reinforcing ribs around the FRP outer shell, and the FRP inner shell. A thermoplastic resin sheet provided between the FRP outer shell and the sheet, and a thermoplastic resin sheet provided between the FRP outer shell and the sheet, wherein the thermoplastic sheet is the inner shell. Is characterized by having a curvature along the outer periphery of and the surface having irregularities.

The inventor of the present invention uses a thermoplastic resin sheet having a curvature along the outer circumference of the inner shell and irregularities on the surface thereof in advance to form the FRP double shell tank cylindrical portion into filament winding molding. We have succeeded in manufacturing a new FRP double shell tank cylinder part by utilizing the feature that it can be finally finished on a mandrel that is a mold of the method (hereinafter referred to as “FW method”).

The FW method is a molding method that can most effectively utilize the tensile strength of reinforcing fibers such as glass fibers, and has the characteristic that the anisotropy can be freely selected by changing the winding angle.

In the present invention, as the method for forming the FRP double-shell tank, the FW method having such characteristics is particularly used, and the curvature along the outer periphery of the inner shell and the By using a thermoplastic sheet with irregularities on the surface, a gap for leak detection can be efficiently provided between the inner and outer shells of the FRP, resulting in high productivity. In addition, we have succeeded in providing an FRP double shell tank cylinder that is extremely economical.

As described above, according to the present invention, the manufacturing process can be reduced, the labor cost can be reduced, the cost can be reduced, and the productivity and the economic efficiency are almost the same as those of the conventional SF double shell tank. Can be secured.

As the radical curable thermosetting resin used for the FRP layer in the FW method, an unsaturated polyester resin can be used, and any of these resins can be a commercially available product. Since the contents of the FRP double shell tank are supposed to be gasoline, corrosion resistance is required, and isophthalic acid type, terephthalic acid type or bisphenol type is particularly preferable as the unsaturated polyester resin. Epoxy acrylate resins are also more desirable because they generally have better corrosion resistance than unsaturated polyester resins. A filler, a coloring material, or the like may be added to the resin as long as it does not affect the quality of the resin and the FRP produced.

As the reinforcing fiber in the FRP layer, glass fiber can be preferably used, and the glass content of the FRP layer is not particularly limited, but it is 48 to 50 in consideration of easiness of molding, strength and elastic modulus. A weight% range is desirable. The glass fiber may be wound on the mandrel in any of parallel, helical, polar, and level winding methods.

As the thermoplastic sheet, those made of polystyrene, polyvinyl chloride, or polymethacrylic resin can be used.

The film provided between the thermoplastic sheet and the outer shell must be selected so that it does not dissolve in the styrene monomer contained in the unsaturated polyester resin or epoxy acrylate resin used, such as polyethylene, It is possible to use polypropylene, polyethylene terephthalate (polyester), or polyvinylidene chloride.

[0021]

[Embodiment of device]

 The present invention will be described in more detail with reference to the drawings. The FRP inner shell composed of glass fibers (mainly glass roving) and radical-curable thermosetting resin can be provided on the mandrel using the FW method, and its thickness is economical. Then, it is preferably 4 to 6 mm.

FIG. 1 or FIG. 2 shows a thermoplastic sheet 1 which is shaped by vacuum forming and is provided with a curvature corresponding to the curvature of the unevenness and the inner shell. As the sheet forming method, any of straight forming, pressure forming, plug assist forming, drape forming, and pressure bubble immersion forming can be used. The shape and size (dimension) of the sheet 1 are not particularly limited, but it is desirable that the shape is a square or a rectangle because they can be installed along the inner shell without spacing, and when the dimension is, for example, a square, a vacuum is applied to the sheet. A flat plate with a maximum size of 1000 mm × 1000 mm is desirable in view of the need to provide unevenness and curvature in molding and the workability of molding. The thickness is preferably in the range of 1 to 2 mm in consideration of the ease of vacuum forming and the economical efficiency.

The shape of the convex portion of the sheet may be any shape such as a triangular shape, a quadrangular shape, a pentagonal shape or a circular shape such as a circle or an ellipse, and the size thereof is about 25 to 100 mm ² for the inner shell and the outer shell. It is preferable from the viewpoint that a sufficient gap is provided between the shell and the leakage liquid so that the leakage liquid does not stay therein. In order to set the distance between the inner and outer shells of the FRP layer to about 3 mm, the size of the convex portion of the sheet is 5 to 10 mm in case of a square (see FIG. 1), and 3 in case of a circle is a diameter. Is preferably in the range of 5 to 10 mm (see FIG. 2), the distance between the convex portions at that time is in the range of 20 to 30 mm, and the height of the convex portions is required to be 3 to 6 mm. In addition, between the convex portions, continuous rod-shaped convex portions 4 are provided at intervals of 100 to 200 mm in order to suppress deformation of the convex portions of the sheet during FW molding (see FIGS. 1 and 2). The sheet is placed on the surface of the inner shell so that the convex portions face the inner shell as shown in FIGS. 1b, 2b, 3 and 4.

The film is provided on the sheet. The film is used to maintain a void layer by the sheet and prevent radical-curable thermosetting resin and glass fiber, which is a reinforcing material, from entering the concave portion of the sheet formed by vacuum forming. It is indispensable to prevent this when it is dissolved by the ingredients contained in.

The FRP layer of the outer shell is formed by the same method as the FW method with the inner shell. The thickness of the FRP layer of the outer shell is preferably in the range of 6 to 8 mm in consideration of economy, and the glass content thereof is not particularly limited, but is preferably in the same range as the FRP layer of the inner shell.

The leak detection device is installed so that the tip of the sensor is located in a gap provided between the inner shell and the outer shell (see FIG. 4).

The tank cylindrical portion is reinforced by a rib separately prepared on the outer shell to obtain a FRP double shell tank cylindrical portion. The rib reinforcement on the outer shell is provided to keep the amount of deformation of the cylindrical portion of the tank within a certain range. Considering the ease of forming and the economical efficiency, the reinforcing ribs provided around the outer shell are considered. It is desirable that the width is about 50 mm and the height is about 80 mm, and the rib interval of the cylindrical portion needs to be at least 2000 mm or less so that the deformation amount of the cylindrical portion is within 3% of the diameter.

[0028]

【Example】

 As shown in FIG. 3, on the mandrel 9 having a diameter of 2100 mm coated with a release agent, an FW molding method using a glass roving and an isophthalic unsaturated polyester resin Yupica 5530P (trade name) manufactured by Nippon Yupica Co., Ltd. Then, the inner shell FRP layer 5 having a glass content of 49% by weight and a thickness of 4 mm was formed.

A polymethacrylic resin sheet having a thickness of 1 mm and a size of 1000 mm × 1000 mm is vacuum-formed, and the size of the convex portion is 5 mm × 5 mm (square shape), the curvature of 1054R, the interval between the convex portions is 25 mm, and the convex portion A sheet 1 (see FIG. 1) having a height of 5 mm and a protrusion 2 continuous in the circumferential direction at intervals of 125 mm between the protrusions was prepared in advance, and the sheet 1 was molded into an inner shell. It was arranged on the surface of the FRP layer 5 as shown in FIG. 3, and a 25 μm polyester film 6 was coated thereon. An outer shell FRP layer 7 having a glass content of 49% by weight and a thickness of 8 mm was formed on the upper surface by the same method as the method of forming the inner shell FRP layer. As shown in FIG. 5, the leak detection device 10 was installed so that the tip of the sensor 11 was located in the space between the inner shell and the outer shell. Next, separately formed reinforcing ribs 8 having a width of 50 mm and a height of 80 mm were attached at intervals of 1000 mm (see FIG. 5). The average gap between the inner shell and the outer shell of the obtained FRP double shell tank cylinder was 2.9 mm, and the amount of deformation of the cylinder was 1.9% of its diameter.

[0030]

[Effect of device]

 As is clear from the above description, since the present invention can provide the voids with extremely high efficiency and high productivity, it is possible to obtain the FRP double shell tank cylindrical portion that can be finally finished on the mandrel. it can. Moreover, even if it is compared with the conventional SF double-shell tank, it is possible to realize almost the same economic efficiency. It is also lightweight and easy to transport.

[Brief description of drawings]

FIG. 1 is a schematic view showing a vacuum-formed thermoplastic sheet according to an example of the present invention.

FIG. 2 is a schematic view showing a vacuum-formed thermoplastic sheet according to another example of the present invention.

FIG. 3 is a schematic view showing a cross section of an FRP double-shell tank cylindrical portion according to an example of the present invention.

FIG. 4 is a schematic view showing a cross section of an FRP double shell tank cylindrical portion according to an example of the present invention.

FIG. 5 is a schematic view showing a reinforcing rib shape of a cylindrical portion of an FRP double-shell tank and an interval thereof according to an example of the present invention.

[Explanation of symbols]

 1 Thermoplastic Sheet 2, 3 Convex 4 Bar-shaped Convex 5 Inner Shell 6 Film 7 Outer Shell 8 Reinforcing Rib 9 Mandrel 10 Leakage Detector 11 Leakage Sensor

Claims (4)

[Scope of utility model registration request] 1. A reinforced plastic inner shell, a reinforced plastic outer shell, reinforcing ribs on the periphery of the reinforced plastic outer shell, and between the reinforced plastic inner shell and the outer shell. A thermoplastic sheet,
It is provided with a film provided between the reinforced plastic outer shell and the sheet, and the thermoplastic plastic sheet has a curvature along the outer periphery of the inner shell and unevenness on its surface. FRP double shell tank cylindrical part characterized by. 2. The FRP double shell tank cylindrical portion according to claim 1, wherein the reinforced plastic inner shell, the thermoplastic plastic sheet, the film and the reinforced plastic outer shell are provided by a filament winding method. . 3. The FF double-shell tank cylindrical portion according to claim 1, wherein the thermoplastic sheet has an uneven portion previously formed by vacuum forming. 4. The protrusions of the thermoplastic sheet have a size of 25 to 100 mm ² , and a distance between the protrusions of 20 to 100 mm ² .
30 mm, height 3-6 mm, spacing 100-200
The FRP double-shell tank cylindrical portion according to any one of claims 1 to 3, further comprising a continuous rod-shaped convex portion for each mm.