EA016465B1 - Spacer for a leak-resistance lining of a tank - Google Patents

Abstract

The invention relates to a spacer for a leak-resistant lining of a tank to form a monitorable cavity between a tank wall (34, 45) and a coating (39) of the spacer. The spacer (11) consists of a spatially formed paper (21) provided with a metal coating (10). The invention also relates to a leak-resistant lining using such spacer and a double-walled tank using such leak-resistant lining.

Description

The invention relates to a spacer device for a tank liner that protects against leakage.

Tanks are known to be equipped with leak-proof lining to make them double-walled and thus leak-proof. To do this, spacers are used that ensure that there is an air space between the cladding that protects against leakage and the outer wall of the tank, which can be deposited at high pressure or vacuum, which can be used to control its density and thereby the density of the cladding that protects against leakage. When leaks are detected, the problem arises of finding a leaking place of the cladding that protects against leakage.

To check for leaks in the wall of the polymer material, it has already been proposed to feel the wall of the polymer material with a high voltage electrode, while moving the opposite electrode on the opposite side of the wall.

From Swiss patent specification No. 532779, a method for searching for leaking double-walled tank locations is known. This method consists in the fact that the wall being checked and spaced from the others consists of a polymeric material and is checked for breakdown by probing with a high-voltage electrode. In contrast to the prior art conventional at that time, it was proposed to fill the cavity with an electrolyte, which serves as the opposite electrode.

In addition, from the Swiss patent specification No. 517630 it is known to use aluminum bubble foil as a spacer device and at the same time the opposite electrode. The density of the synthetic resin layer below the aluminum bubble film can be monitored by the high voltage electrode. Always where there is a loose place in this layer or where a shell is located in the layer, the electrical resistance of the synthetic resin layer is lower, and a spark breaks from the electrode onto the bubble foil.

Aluminum bubble foil, however, is a relatively expensive cladding material to protect against leakage of the cladding.

EP-A-1602597 therefore goes back again to the old technology and uses bubbly cardboard as a spacer to protect the cladding from leakage. However, it was established that the market does not want to give up density control through the so-called sprinkling.

Therefore, the object of the invention is to propose an economically favorable spacer device that forms the opposite electrode and thereby makes it possible to check the synthetic resin layer deposited on top of it by feeling with a high-voltage electrode for electrical breakdown.

In accordance with the invention, this problem is solved by the features of an independent claim. This means that the spacer device in accordance with the invention is made of bulk-formed paper provided with a metallized layer and can be stored and transported in roll form. Due to this, the material having the necessary stiffness is very economical. However, the paper on its surface has conductivity, since there is a metallized layer. This metallized layer can be made very thin.

The metal of the metallized layer is expediently sprayed onto the paper. This method has the advantage that a layer is obtained without empty spaces and the material costs are very small.

The paper is predominantly impregnated. Due to the impregnation, the upper surface of the paper is so continuous that the sprayed metallized layer already forms a continuous layer even with a small layer thickness.

The paper has, it is advisable, at least on one side of the bubbles, with which it lies exclusively on a substrate. Due to this, the cavity between the paper and the wall of the tank is not divided by means of any areas that are linearly adjacent to the shell of the tank into different sections, but appears as an undivided space.

The paper has, expediently, on the first side of the cavity facing the wall of the tank and bubbles rising between them, and on the opposite side there are edges corresponding to the cavities and separated by these edges, corresponding to the deflection bubbles. This embodiment is well established on bubble cardboard not coated with the invention.

The metallized layer is preferably applied to the back of the bubbles on the paper, so that it lies on the side of the paper facing the inside of the tank in a leak-proof liner.

The metal of the metallized layer is preferably aluminum.

In the case of a leakproof liner with a spacer device according to the invention for forming a controlled cavity between the leakproof liner and the wall of the tank, the spacer of which consists of a volumetric formed and at least one side having a metallized layer of paper, the metallized layer is expediently located on the provided layer synthetic resin side paper. Due to this, this conductive layer lies directly on the reverse side of the density-tested synthetic resin layer.

- 1 016465

The invention also relates to a double-walled tank with such a leakproof liner.

Brief description of the figures:

FIG. 1 shows a schematic representation of materials for a leakproof lining with a controlled cavity;

FIG. 2 shows schematically a cut-out of a spacer device with truncated pyramids, wherein the edge of the roll material of the spacer device is partially covered with aluminum adhesive tape;

FIG. 3 shows schematically a cut-out of a spacer with truncated cones;

FIG. 4 shows a schematic sectional perspective view of a spacer device according to FIG. 2;

FIG. 5 shows a schematic vertical section through a lined cubic tank according to the invention;

FIG. 6 shows a schematic oblique section through a lined cylindrical tank according to the invention.

Presented in FIG. 1 materials allow leak-proof linings to be placed in or on the tank. In the known method, it is a bubble spacer device 11 of a large surface and a polymer material 13. The polymer material 13 is applied in liquid form to the spacer device 11 and thus has such properties that it cures onto it into a layer of synthetic resin. In this case, the polymer material is in a container 19 suitable for liquids. This is, as a rule, a two-component polymer material, the components of which, contrary to what is shown, are presented in two separate containers.

For mounting the spacer device 11 on the tank wall, a double-sided adhesive tape 15 can be provided. An aluminum adhesive tape 16 is used to seal the seam between the two sheets and to electrically connect the layer 16. To reinforce the layer, a fibrous non-woven fabric or fabric 17 can be provided. tools for applying these materials. It can be a spray gun, roller, spatula or similar.

The spacer device 11 shown is bubble paper. Paper 21 may be stored and transported as roll material. The thickness of the paper is uniform and very small. A sufficient strength of the spacer device 11 was achieved with a mass of 90 g / m ^2. Such paper 21 can be impregnated with polymeric material 13 without causing significant deformations. The structure of the paper 21 is characterized by cruciform grooves 23 and within the quadrangular planes between the grooves 23 of each bubble 25. The bubble 25 may, as shown in FIG. 2 and 4, have the shape of a quadrangular truncated pyramid. It can also, as shown in FIG. 3, be cylindrical or in the shape of a truncated cone. Triangular truncated pyramids are also possible.

An aluminum layer is sprayed onto the bubble paper on one side. This sprayed metallized layer is naturally conductive. He is very thin. When comparing paper with a coated layer and without a coated layer, the difference in surface structure is not visible to the eye. The color of the coated surface is naturally metallic, while the uncoated surface has the color of a paper.

Wrapping paper with a thickness of approximately 145 μm is commercially available, the grooves 23 of which form a diagonal rhombic network. This preferably non-bleached kraft paper has a surface weight of 96 to 104 g. Roughness of the paper without spraying is indicated as 1200 ± 500 ml / min (Roughness / Smoothness according to Ppxysp). The bubbles 25 have the shape of a truncated pyramid, their base has twice the length of the sides than their truncated platform 27. These truncated pyramids have a height of about 1 mm. The mesh size from the groove to the groove 23 is 7 mm. This packaging paper is impregnated, however, with open pores and is hygroscopic. The grooves 23 extend at an angle of 45 ° to the long edge 22 of this web material.

This wrapping paper for cladding is coated by spraying aluminum with a spray device. The roll material is furthermore processed in a continuous manner. Due to the impregnation of the paper, the structure of the outer surface of the paper is relatively compact. Individual paper fibers are only occasionally spaced from the surface of the paper. Thanks to this, an economical and gap-free coating is possible.

As seen in FIG. 1-3, spray coating 10 may not be sufficient on paper 21 at the edges. This area of the edges is overlapped with the overlap when laying the spacer 11. The electrical connection of the conductive metallized layer is achieved by gluing the conductive aluminum adhesive tape 16.

In FIG. 4 shows the edge of the wrapping paper. The extrusion of bubbles 25 and grooves 23 occurs along the entire plane of the paper. In this case, the edge of the paper passes as a cut line diagonally through the bubbles and grooves. Due to this diagonal arrangement of the grooves 23 after installing this paper as a spacer device in the lining of the tank wall, the grooves extend diagonally in the plane of the tank wall.

In FIG. 5 is the passage of the grooves 23 inside the leakproof lining 31 is shown

- 2 016465 dashed line. These grooves 23 extend parallel and cross diagonally through the rectangular quadrangles of the walls of the tank 33.

Tank 33 has a rigid shell 34 in the form of a horizontal bottom 35 and four vertical walls 37. The shell 34 is presented in the form of a concrete structure. It may have an older coating. It may also consist of other materials. Bubble paper 21 is deposited on this shell 34, which has been truncated onto the outer surface of the shell by truncated pads 27 (FIG. 4) of bubbles 25. The air volume of the grooves 23 forms a controlled cavity 29 between the tank shell and the bubble paper 21. The aluminum-coated surfaces are located on the visible side of the coated bubble paper. On this side of the bubble paper 21 facing away from the shell, there are concave inner sides of the bubbles 25, like recesses between linear elevations. The linear elevations are the convex reverse sides of the grooves 23. A polymer material is deposited on these coated elevations and in these coated depressions. Despite the metallized layer, the polymer material 13 impregnates all the paper 21 and forms a layer of polymer material 39 with a thickness much less than the thickness of the paper 21. The fibers of the bubble paper 21 form the fibrous reinforcement of the layer 39 of the polymer material. However, the surface conductivity of the metallized layer is specified.

In the polymeric material 13 of the layer 39 of the polymeric material in accordance with FIG. 5, however, fiberglass reinforcement 17 is also preferably laid. This fiberglass reinforcement is a two-layer fiberglass fabric 17. This two-layer fiberglass fabric 17 is enclosed in a layer 39 of plastic.

In FIG. 5, moreover, the cover layer 41 of the cover 31 is shown. This cover layer may consist of a material acceptable for food or drinking water or make the cover suitable for other special applications.

In FIG. 6 shows how the bubble paper web 21 is stacked in a cylindrical tank. Presented in FIG. 6, the tank 43 has an approximately cylindrical steel shell 45. It is coated on its inner side with bubble paper 21. The truncated areas 27 of the bubbles 25 (see FIG. 4) are adjacent to the shell 45. The aluminum-coated bubble paper 21 is impregnated on one side and coated with polymer material. Coating with a polymeric material is preferably carried out in two layers. Where the stiffness of the connection of the polymer material and the paper is insufficient, another layer of plastic fiberglass or fiberglass fabric may be provided.

The canvases 47 of paper roll material 11, 21 are preferably laid in the direction of the perimeter of the cylinder 45. The grooves 23 on the bubble paper 21 extend along the diagonally forming cylinder 45 and extend in the direction of the perimeter of the circle line of the cylinder 45.

Such a leakproof liner is mounted as follows: first, a durable tank shell is made or cleaned. A metal-coated bubble paper 21 is superimposed on this tub envelope 34, 45. The bubble paper grooves 23 thus form intersecting channels between the paper 21 and the tub liner 34, 45. The paper is stacked in such a way that these channels extend at an angle that clearly deviates from 0 and from 90 ° to the bending direction of the bubble paper 21. The bending direction is determined by the direction of the edge of the coated planes or the direction of the smallest arc of curvature of the tank shell.

In order for the bubble tape 21 to hold, it can, for example, be fixed to the shell 34, 45 with double-sided adhesive tape 15 (FIG. 1) or other adhesive means. Now the bubble paper 21 is impregnated with a liquid polymer material 13 (Fig. 1). As a polymeric material, Erohu Νονοίαο and Erohu Ζίΐΐοαίίρΐιαΐ are primarily taken into account. But other epoxies, as well as polyurethane resins and polyester resins, can also be used. Synthetic resin is applied on one side.

Bubble paper can also be impregnated with synthetic resin before mounting. After setting the synthetic resin, the impregnated bubble paper 21 is wear resistant. Therefore, the bubble paper 21 treated with synthetic resin 13 can be used in areas in which the bubble paper 21 must be bypassed during installation.

Advantageously, the treated bubble paper 21 is not impregnated with synthetic material over the entire width of the web. Edge areas may remain untreated. Raw areas of the edges of the bubble paper 21 may be overlapped. In the overlapping region of adjacent bubble paper webs, bubbles 25 and grooves 23 can be brought into coincidence. Because of this, in the place of overlap there is practically no overlap of the cavity. Raw areas of the edges are glued together by an aluminum tape 16. This tape 16 glues adjacent webs to each other with electrical conductivity. Due to this, the metallized layer 10 forms an opposite electrode passing over the entire surface of the cladding that protects against leakage.

Ceilings and all untreated canvases of bubble paper are impregnated with a polymer material. Treated areas can be covered with synthetic resin. Preferably, fiberglass reinforcement is laid and pressed in by a roller into a synthetic resin that has not yet hardened. Synthetic resin is applied to fiberglass reinforcement. If shells have formed between the bubble paper and the fiberglass reinforcement, they are impregnated with a roller along the edge of the canvas

- 3 016465 made of fiberglass, and thus the fiberglass or fiberglass is laid practically without shells in a synthetic resin.

Fiberglass is preferred which has greater intrinsic stability compared to conventional fibers. Double layer fiberglass is particularly preferred.

The liner thus protected against leakage is now checked for density, which creates a vacuum in the intermediate space between the bubble paper and the tank shell. Air passing through leaks reduces vacuum in the intermediate space. The decrease in rarefaction in the intermediate space indicates leaks in the cladding that protects against leakage. This leak can only be detected by means of a high-frequency spark flaw detector. Places where the spark from the device slips onto the leak-proof lining (more precisely, onto the metallized coating of paper) are potentially leaky. In these places, the synthetic resin coating is either loose or has a shell. If no leak points are identified or if the leak points are sealed, then the outer surface of the cladding protecting against leakage may still be provided with a coating layer of a polymer material specialized in the use. This polymer material is specifically designed for liquid that must be stored in a lined tank. It is also possible to overlay the outer surface with ceramic tiles.

Claims (10)

CLAIM 1. A spacer (11) capable of storing and transporting in roll form to create a tank lining (39) that protects against leakage, with a controlled cavity being formed between the shell (34, 45) of the tank and the lining (39) of the spacer (11) (29), and the spacer device is made of volume-formed paper (21), characterized in that the volume-formed paper (21) is provided with a metallized coating (10). 2. The spreader device according to claim 1, characterized in that the metal of the metallized coating (10) is sprayed onto the paper (21). 3. The spreader device according to claim 1 or 2, characterized in that the paper (21) is impregnated. 4. The expansion device according to one of claims 1 to 3, characterized in that the paper has bubbles on at least one side, so that this side only points to the substrate. 5. The spreader device according to claim 4, characterized in that the paper (21) on the first side facing the shell (34) of the tank has grooves (23) and bubbles (25) towering between them, and on the opposite side - corresponding to the grooves ( 23) edges and corresponding edges separated by bubbles (25) of the recess. 6. The spreader device according to claim 4 or 5, characterized in that the metallized coating (10) is applied to the paper (21) on the reverse side of the bubbles (25). 7. The spreader device according to one of the preceding claims, characterized in that the metal of the metallized coating (10) is aluminum. 8. A leak-proof lining with a spacer (11) to form a controlled cavity (29) between the leak-proof lining and the tank shell (34), the spacer device (11) consisting of volume-formed paper (21) and provided with a layer (39 ) synthetic resin, characterized in that the spacer device (11) is a spacer device according to one of claims 1 to 7. 9. The leakproof lining of claim 8, characterized in that the metallized coating layer (10) lies on the side of the paper (21) provided with a layer of synthetic resin. 10. Double-walled tank with leakproof lining according to claim 8 or 9.