CN109808168B

CN109808168B - Tank and method of lining a tank

Info

Publication number: CN109808168B
Application number: CN201711160779.3A
Authority: CN
Inventors: 马库斯·莱切哈尔乐; 彼得·沃思
Original assignee: Wolftank-Adisa Holding AG
Current assignee: Wolftank-Adisa Holding AG
Priority date: 2017-11-20
Filing date: 2017-11-20
Publication date: 2021-05-28
Anticipated expiration: 2037-11-20
Also published as: RU2018140782A; CN109808168A

Abstract

The invention relates to a method for lining an inner wall (2) of a tank (1), comprising: a spacing layer (5) is arranged on the inner wall (2), and the spacing layer can permeate air and conduct electricity in the direction parallel to the inner wall; -placing a reinforcement layer (9) on top of the spacer layer (5), the reinforcement layer (9) having glass or carbon fibres embedded in a liquid first synthetic resin (10); -placing a sealing layer (12) on top of the reinforcement layer (9), the sealing layer (12) having a non-woven material (13) embedded in a liquid second synthetic resin (14); -curing the first synthetic resin (10) and the second synthetic resin (14); and placing an electrically conductive top layer (15) on top of the cured sealing layer (12). The invention also relates to a tank (1) lined according to the method.

Description

Tank and method of lining a tank

Technical Field

The present invention relates to a method of lining the interior walls of tanks, and in particular to a method of lining the interior walls of underground or above ground storage tanks for mineral oil, solvents, acids, bases and the like. The invention also relates to a lined tank.

Background

The application of a protective liner on the inner wall of a tank can serve two purposes, either to repair a leaky tank or to retrofit a single wall tank with a double wall system. In a double wall system, the gap between the two walls can be monitored for changes in pressure that indicate a leak in one of the walls. The liner includes spacers that form the gap, while the original inner vessel wall forms the outer wall of the double wall system.

EP 2055404B 1 describes coating the spacer with a reinforcing layer of liquid glass fibre-reinforced synthetic resin, which is then cured and covered with a conductive top layer for grounding. However, the glass fibers of the reinforcement layer may penetrate the top layer, thereby creating micro-pores that affect the sealability of the liner. It is therefore proposed to apply a sealing layer on top of the reinforcement layer, for example by spraying a separate layer of liquid synthetic resin on top of the cured reinforcement layer. However, this is a time consuming process and the resulting overall structure is not satisfactory in terms of leak testing tightness, durability and usability.

Disclosure of Invention

It is an object of the present invention to provide an improved lined method and lined tank which overcomes the disadvantages of the prior art.

To this end, in a first aspect the present invention provides a method of lining an inner wall of a tank, the method comprising:

a spacing layer is arranged on the inner wall, and the spacing layer can permeate air and conduct electricity in the direction parallel to the inner wall;

placing a reinforcement layer on top of the spacer layer, the reinforcement layer having glass or carbon fibers embedded in a liquid first synthetic resin;

placing a sealing layer on top of the reinforcement layer, the sealing layer having a nonwoven material embedded in a liquid second synthetic resin;

curing the first synthetic resin and the second synthetic resin; and

a conductive top layer is placed on top of the cured sealing layer.

Placing a non-woven material on a reinforcement layer and curing the reinforcement layer with glass or carbon fibres and the sealing layer with non-woven material in one step results in the dual advantages that a separate, time-consuming curing of the reinforcement layer is avoided and the non-woven material of the sealing layer is impregnated with the first and second resins. After curing the resin, a completely tight and leak-free closure of the reinforcement layer is established. The nonwoven material presses down the glass or carbon fibers of the reinforcement layer, preventing them from penetrating the top layer, which could otherwise cause capillary leakage. Finally, the method combines the rapid and safe application of the liner with the enhanced durability, sealing and usability of the liner.

Two different resins can be used for the first resin and the second resin of the reinforcement layer and the sealing layer. For example, it is possible to use resins of different viscosities, for example, a higher viscosity resin for the first synthetic resin and a lower viscosity resin for the second resin. However, it is preferable that the first synthetic resin and the second synthetic resin are the same to facilitate manufacture of the in-situ liner.

In a preferred embodiment of the invention, placing the sealing layer comprises placing the nonwoven material in the form of a plurality of nonwoven mats on top of the reinforcement layer and coating the nonwoven mats with the liquid second synthetic resin. The non-woven mat may be made of Glass fibers, particularly of the type C-Glass or ECR-Glass (E-Glass of Chemical Resistance, E Chemical resistant Glass). Preferably, the weight of the non-woven mat is in the range of 30-100 grams per square meter.

In particular, the second synthetic resin is roll-coated (roll-spread) or sprayed onto the nonwoven mat. All of these measures provide good impregnation and embedding of the nonwoven material into the second resin when the second resin is intimately bonded to the first resin. Furthermore, the non-woven material is thick enough to cover the glass or carbon fibres of the reinforcement layer and prevent them from penetrating the sealing layer.

In another preferred embodiment of the invention, placing the reinforcement layer comprises placing a plurality of said glass or carbon fibres in the form of a fibre mat on top of the spacer layer and coating the fibre mat with the liquid first synthetic resin. The fibrous mat may be a woven glass fibre structure, in particular with a non-twisted fibre structure. Preferably, the weight of the fiber mat is in the range of 200-500 grams per square meter.

Preferably, the first synthetic resin is roll-coated or sprayed onto the fibrous mat so that a coating, i.e. roll-coating or spraying, may be used to coat the resin of the reinforcement layer and the sealant layer.

In any case, the spacing layer may comprise a corrugated or embossed aluminum foil or sheet capable of establishing the necessary gap for leak monitoring and conductivity for leak testing by spark brushes (spark brushes), as will be explained below.

Preferably, the aluminium foil or sheet is enamelled (enamelled) at least on the side facing the reinforcing layer. The use of an enamelled aluminium foil or sheet improves the bonding of the reinforcing layer to the spacer layer, since the synthetic resin of the reinforcing layer tends to stick to the enamel (glaze) of the spacer layer.

In another embodiment of the invention, the spacing layer consists of a plurality of corrugated or embossed aluminium foils or sheets that are adjacently superimposed, and fibre-reinforced tapes or ribbons are placed in bridging fashion on adjacent foils or sheets so that when the spacing layer is coated with the reinforcing layer, the fibre-reinforced tapes or ribbons are embedded in the reinforcing layer.

In a second aspect, the present invention relates to a tank lined according to the method described herein.

Drawings

The invention will now be described in further detail with reference to the following drawings, in which:

FIG. 1 is a partial cross-sectional view of a tank lined according to the method of the present invention;

FIG. 2 shows an enlarged detail A of FIG. 1; and

fig. 3 shows an enlarged partial cross-sectional view of another embodiment of a lined according to the present invention.

Detailed Description

Fig. 1 and 2 show in part a tank 1, for example an underground or an above ground storage tank for mineral oil in a gasoline station or refinery. The tank 1 has an inner wall 2. The wall 2 can be made of concrete or metal, can be built as one single container or as parts welded together, for example by seams 3.

The inner wall 2 of the tank 1 should be lined with a lining 4 while establishing a double wall system for the tank 1. To this end, the lining 4 comprises a spacer layer 5 facing the inner wall 2. The spacer layer 5 is permeable to air in a direction parallel to the inner wall 2, so that a gap 6 is formed between the spacer layer 5 and the wall 2. As is known in the art, the gap 6 can be evacuated and the vacuum therein monitored for changes in pressure over time which would indicate leaks in the liner 4 and/or the wall 2.

With reference to fig. 2, the liner 4 is built in situ in the tank 1 as follows.

First, the spacer layer 5 is placed on the inner wall 2. The spacer layer 5 can be any material that allows air to flow in a direction parallel to the inner wall 2 so as to evacuate the gap 6 from only one or more different points on the wall 2. Furthermore, for the spark test explained below, the spacer layer 5 conducts in a direction parallel to the inner wall 2, so as to be electrically grounded at only one or more different points on the wall 2.

The spacing layer 5 can be made, for example, of a corrugated, corrugated or embossed plastic foil or sheet, or of a completely conductive plastic material, or covered by a conductive metal layer. Alternatively, preferably, the spacing layer 5 is a corrugated, corrugated or embossed plastic foil or sheet having a plurality of ribs, protrusions or embossments 7 disposed in an array throughout the spacing layer 5 facing the wall 2. As will be described later, the spacer layer 5 can consist of a plurality of foils or sheets that overlap each other in an overlap region 8 (fig. 3).

Secondly, the spacer layer 5 is coated with a reinforcement layer 9. The reinforcement layer 9 is composed of a liquid resin 10 having glass or carbon fibers embedded therein. The reinforcement layer 9 can be applied as a slurry of liquid resin 10 with micro fibers, e.g. glass or carbon staple fibers having a length in the range of 3-6mm, by coating or spraying on top of the spacer layer 5 with a roller or doctor blade.

Alternatively, the reinforcement layer 9 comprises glass or carbon fibres in the form of woven or non-woven fibre mats 11, which are embedded or impregnated with a liquid resin 10, for example in the form of a prepreg. Furthermore, the synthetic resin 10 of the first layer can be applied or sprayed onto said spacing layer 5, filling the embossings 7. Next, the fiber mat 11 is laid out, and then a second layer of the synthetic resin 10 is spread or sprayed on the fiber mat, and the resin 10 is poured through the slits of the mat 11 and combined with the first layer of the resin 10, thereby embedding the fiber mat 11 in the synthetic resin 10.

The weight of the fiber mat 11 can be in the range of 200-500 g/m and/or the thickness of the fiber mat 11 can be in the range of 1-2 mm, for example a woven glass fiber structure, in particular with a non-twisted fiber structure.

When an aluminium foil or sheet is used for the spacer layer 5, it is preferred that at least the side of the aluminium foil or sheet facing the reinforcement layer 9 is lacquered. This ensures a good bond between the spacer layer 5 and the reinforcing layer 9, since the synthetic resin 10 easily sticks to the enamel (glaze) of the spacer layer 5.

After the reinforcement layer 9 has been applied and while the synthetic resin 10 of the reinforcement layer 9 is still in a liquid state, a sealing layer 12 is placed on top of the reinforcement layer 9. The sealing layer 12 comprises a non-woven material 13 embedded in a synthetic resin 14, the non-woven material 13 being fused or bonded with the synthetic resin 10 of the reinforcement layer 9. The nonwoven material 13 may be continuous or in the form of a plurality of nonwoven mats that may (or may not) be adjacent to one another.

The weight of the nonwoven material 13 is in the range of 30-100 grams per square meter and/or the thickness of the nonwoven material 13 is in the range of 0.3-0.5 millimeters. In one embodiment, the nonwoven material 13 can be made of polyester fibers, for example, incorporated in an acrylate or the like. In another embodiment, the nonwoven material 13 is made of glass fibers, in particular of glass fibers of the c-glass or ECR-glass type, wherein "c-glass" refers to a glass with corrosion resistance made of calcium borosilicate and "ECR-glass" refers to a resistive glass with higher corrosion resistance made of alumino-calcium silicate.

The sealing layer 12 with the nonwoven 13 can be applied to the reinforcement layer 9 in different ways. In one embodiment, the non-woven material 13, either continuous or in the form of a mat, is pre-impregnated with the synthetic resin 14 and placed on top of the reinforcement layer 9. In another embodiment, the nonwoven material 13 is first placed on top of the reinforcement layer 9 or, more precisely, on the exposed surface of the synthetic resin 10, and the nonwoven material 13 is then coated with the liquid synthetic resin 14 impregnating the nonwoven material 13.

After the laminate composed of the reinforcing layer 9 and the sealing layer 12 is built up in this way, the synthetic resin 10 of the reinforcing layer 9 and the synthetic resin 14 of the sealing layer 12 are cured (hardened), for example, by self-curing in the case of a two-component synthetic resin or with the aid of light or heat when a light-curing or heat-curing resin is used.

The

synthetic resins

10,14 of the reinforcing and sealing

layers

9,12 may be different or may be identical. For example, the synthetic resin 10 of the reinforcing layer 9 has a high viscosity in its liquid state, for example, in the range of 2000-10000 mPas at 25 ℃, preferably in the range of 3000-8000 mPas at 25 ℃, particularly preferably in the range of 5000 mPas at 25 ℃. In contrast, the viscosity of the synthetic resin 14 of the sealing layer 12 is much lower than the viscosity of the liquid resin 10 of the reinforcing layer 9, and the viscosity of the synthetic resin 14 of the sealing layer 12 is, for example, lower than 3000 mpa.s at 25 ℃, preferably lower than 2000 mpa.s at 25 ℃, particularly preferably lower than 1000 mpa.s at 25 ℃, for example 500 mpa.s at 25 ℃. By using a low viscosity liquid for the sealing layer 12, the thickness of the sealing layer 12 can be minimized while the pores of the reinforcement layer 9 are easily accessed, closed and sealed when the sealing layer 12 is applied.

On the other hand, when the two

synthetic resins

10,14 are the same, the manufacturing process of the liner 4 is simplified.

After the reinforcing and sealing

layers

9,12 have hardened, the tightness of the (as yet unfinished) lining 4 can be tested by means of a "sparking" test. In this test, a high voltage brush (not shown) is moved or rolled over the completed sealing layer 12 while the spacer layer 5 is electrically grounded. In the case of the occurrence of pinholes in the reinforcing

layers

9,12 or thinning of the reinforcing

layers

9,12, discharge sparks indicating leakage or failure can be observed when the high-voltage brush is moved in the vicinity.

Finally, a top layer 15 is placed on top of the cured reinforcement and sealing

layers

9, 12. The top layer 15 is applied as a liquid, preferably a conductive material, such as a synthetic paint containing graphite, carbon, mica or metal particles. The top layer 15 is then hardened, for example by drying out, and finally electrically grounded.

Fig. 3 shows a variant of placing the spacer layer 5, wherein the spacer layer 5 is in the form of a plurality of separate foils or sheets overlapping each other in an overlap region 8. A plurality of fibre-reinforced tapes or strips 16 bridge these overlapping regions 8, i.e. from one foil or sheet of the spacer layer 5 across to its neighbouring foil or sheet. For example by applying a first portion of synthetic resin 10 on top of the overlapping foil or sheet of the spacer layer 5, embedding a number of said strips 16 in the synthetic resin 10 of the reinforcing layer 9, then placing the strips or strips 16 in the areas 8, and then applying the next portion of synthetic resin 10 of the reinforcing layer 9 on top. The tape 16 or tapes 16 may be, for example, woven or non-woven glass or carbon fibre mats, which may also be synthetic resin pre-impregnated with the reinforcement layer 9 in the form of prepregs.

The present invention is not limited to the particular embodiments disclosed herein, but encompasses all variations, modifications, and combinations that fall within the scope of the appended claims.

Claims

1. A method of lining an inner wall (2) of a tank (1), comprising:

a spacing layer (5) is arranged on the inner wall (2), and the spacing layer can permeate air in the direction parallel to the inner wall and can conduct electricity in the direction parallel to the inner wall;

-placing a reinforcement layer (9) on top of the spacer layer (5), the reinforcement layer (9) having glass or carbon fibres embedded in a liquid first synthetic resin (10);

-placing a sealing layer (12) on top of the reinforcement layer (9), the sealing layer (12) having a non-woven material (13) embedded in a liquid second synthetic resin (14);

-curing the first synthetic resin (10) and the second synthetic resin (14); and

on top of the cured sealing layer (12) an electrically conductive top layer (15) is placed.

2. The method according to claim 1, wherein the first synthetic resin (10) and the second synthetic resin (14) are identical.

3. The method according to claim 1, wherein the nonwoven material (13) is made of glass fibers.

4. The method of claim 3, wherein the glass fiber is a C-glass type.

5. The method of claim 3, wherein the glass fiber is an ECR-glass type.

6. A method according to claim 1, wherein placing the sealing layer (12) comprises placing the non-woven material (13) in the form of a plurality of non-woven mats on top of the reinforcement layer (9) and coating the non-woven mats with the liquid second synthetic resin (14).

7. The method of claim 6, wherein the plurality of non-woven mats weigh in the range of 30-100 grams per square meter.

8. The method of claim 6, wherein the second synthetic resin (14) is roll coated or spray coated onto the nonwoven mat.

9. Method according to any one of claims 1 to 8, wherein placing the reinforcement layer (9) comprises placing the glass or carbon fibres in the form of a plurality of fibre mats (11) on top of the spacer layer (5) and coating the fibre mats (11) with the liquid first synthetic resin (10).

10. The method according to claim 9, wherein the fibre mat (11) is made of a woven glass fibre tissue.

11. The method according to claim 9, wherein the fibre mat (11) has a non-twisted fibre structure.

12. The method as claimed in claim 9, wherein the weight of the fibre mat (11) is in the range of 200 and 500 g/m.

13. A method according to claim 9, wherein the first synthetic resin (10) is roll-coated or sprayed onto the fibre mat (11).

14. The method according to any one of claims 1 to 8, wherein the spacing layer (5) comprises at least one corrugated or embossed aluminium foil or sheet.

15. Method according to claim 14, wherein the aluminium foil or sheet is enamelled at least on the side facing the reinforcement layer (9).

16. Method according to claim 15, wherein the spacer layer (5) is constituted by a plurality of aluminium foils or sheets that are adjacently overlapping, and wherein fibre-reinforced tapes or strips (16) are placed in bridging manner on adjacent foils or sheets.

17. Tank with lined inner wall (2), the inner wall (2) being lined with a spacing layer (5), a reinforcement layer (9), a sealing layer (12) and a top layer (15) applied according to the method of any one of claims 1 to 8.

18. A tank lined on its inner wall with a spacing layer (5), a reinforcement layer (9), a sealing layer (12) and a top layer (15) applied according to the method of claim 9.

19. A tank lined on its inner wall with a spacing layer (5), a reinforcement layer (9), a sealing layer (12) and a top layer (15) applied according to the method of claim 14.

20. A tank lined on its inner wall with a spacing layer (5), a reinforcement layer (9), a sealing layer (12) and a top layer (15) applied according to the method of claim 15.