DE7341620U - Transparent tank made of glass fiber reinforced reaction resin molded material - Google Patents

Description

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BASF Akliangisellschaft

Our reference: O. Z- 30 226 Ls / G

67OC Ludwigshafen, November 20, 1973

Transparent tank made of glass fiber reinforced reaction resin molded material

Conventional storage tanks for storing flammable liquids are welded together from sheet steel. Sin significant disadvantage of this Steel tanks are very susceptible to corrosion: flammable liquids, especially heating oil and gasoline, contain more or less less finely divided water, chlorine, etc. Because of these undesirable, but inevitable pollution occurs predominantly Corrosion (pitting) in the lower area of the container, which usually turns into a leak after a few years and thus to the Failure can result.

In particular with underground tanks there is still a strong corrosion effect from the outside through the surrounding, moist soil and / or leakage currents.

For reasons of keeping the groundwater clean, the legislator has therefore double-walled for steel tanks against internal corrosion with leak detection device and against external corrosion jine suitable Priming and insulation required.

It was natural to use as Tankwandungswjrkstoff a corrosion-resistant material, such as a glass fiber-reinforced plastic. Today, for example, glass fiber reinforced poly 3 s resin are successfully used for above and below ground day drinks for wood oil and diesel fuel with internal ages of up to ICO 000 liters.

The Vort.ile of FRP tanks are ^a ll? Rc in r.oher. Corrosion and weather resistant; in the gsringon Gebleut, as well as in the transparency of the material. Disadvantages are the storage of flammable liquids of group A, hazard class I and d

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II and 5 the high electrical surface resistance of around

14th
10 jO. and the resulting electrostatic charge on the surface. Static electricity has been a common cause of fires and explosions. However, especially with the material GRP, this risk can be controlled by various measures.

If the surface resistance is below 10 ^ _O-, measured according to VED 0305 part 3, and the leakage resistance according to DIN 51 953

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solid bodies to be expected. For certain applications, materials can also be used with
he range 25ogeη.

materials with a surface resistance of up to 10 -Q-

The literature shows a multitude of possibilities how the danger of ignition caused by electrostatic charges can be avoided. Above all, they provide important information the "Guidelines for the prevention of dangers due to electrostatic charge" of the professional association of the chemical industry. However, if one assumes the requirement of a GRP container to produce, which is supposed to resemble metal vessels in its electrostatic behavior, then only measures remain, which focus on the material itself. The aim will therefore be to keep the surface resistance below 10 -β and the leakage resistance below 10 - ^ - to lower. Another possibility, the risk of ignition To prevent electrostatic charges, is that electrically conductive grids, metal nets or fleeces into the material at a distance of 0.25 to 2 mm from the surface are embedded (see Kunststoffe, Vol. 59, Issue 12, pp. 838-842).

Conductive, earthed nets placed in the tank wall have the main advantage that the tank walls remain transparent or can be colored in any color. In addition to conductive grids, metal fleece or other conductive ones can also be used Nonwovens are used, provided that Gis reduction or the loss of transparency does not interfere.

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The surface resistance of GRP can be made conductive by adding Fillers (metal powder, carbon black, graphite, etc.) »are reduced by conductive fibers or antistatic agents. Such filler additives have the disadvantage that they result in dark and opaque parts, which leads to defects in the laminate of the wall reveal neither from the outside nor from the inside. Conductive fibers lying on the surface can be damaged by corrosive Influences etc. can easily be destroyed. Consume antistatic agents over time and therefore do not give a lasting effect.

To be as safe as possible, the physical-technical federal institute in Braunschweig proposes a height of 8x8 nm for substances of group A hazard class II, a sinette depth of max. 2 mm, for substances of group A hazard class I a maximum ^{mesh size of ι} Ί χ k cm and a Embedding depth of max.0.25 mm before. In practice, you will work with even closer-meshed networks because they are easier to handle and you can be sure of that.

Conductive grids are wire nets, grids made of metallized synthetic fibers, glass silk fabrics with woven metal threads, graphitized synthetic fiber sheets are suitable, among others. The grid that is used in the manufacture of the container jacket in a suitable In the case of tanks placed underground, it is incorporated up to a maximum of 2 mm below the inner surface of the tank, bsi above-ground tanks also at the same maximum distance from the outer surface.

Transparent floors can be made according to the known manufacturing methods such as pressing, injection molding, hand lamination, injection processes i.a. in the same way by inserting conductive grids, Fleece or similar for the mentioned storage tanks for flammable Produce fluids of group A, hazard classes I and II as well as B.

The conductive barrels ending at the trimmed edge of the container bottom very small cross-sections must be connected to the fiber ends of the Im

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Container shell located grid conductive to a container connected and earthed to the outside. One made do so far üa = ' with, in the production of the floor, e.g. a graphite-containing, i.e. le it ™ able to use resin matrix, however the transparency is lost.

It has now been found that the liquids of group Λ, hazard class I and II (e.g. petrol) and group B (according to VbF) necessary requirements by GFK-LagcFtänkö meets VfSFdSn, bsi rfslohsn sins Conductive connection between the bottom and cylinder grid inlays is present, which is characterized in that an optionally (Ϊ Voluminous conductive material covered by further layers of laminate

Fleece, e.g. a metal fleece as a strip on the edge of the conductive Grid to the next surface is arranged so that over a large number of fibers of the voluminous, conductive Fleece there is an electrically conductive connection between the lattice insert and the tank surface, and the bottom and shell of the transparent tanks through an outer ,,, conductive laminate to each other are connected.

Suitable conductive bulky nonwovens are loose metal webs, such as webs of steel, stainless steels brass or other metal alloys, further webs of metallised or graphical <x oriented fibers having a layer thickness of generally 0.1

2 mm, preferably 1 mm.

For example, if you want to earth the grille to the outside of underground tanks, you only need a wider, conductive, voluminous one Fleece to be arranged so that it initially protrudes beyond the hand of the grid and simply to the grid-removed, i.e. later outer tank surface over the preform or the Glasmatteneinlaga is folded down. This can be done both in the production of the soil as well as before applying the last layer of laminate the sheath production. In order to achieve a conductive contact, you can now use the lank assembly in the area of the joint Tank jacket / floor on the finished part by grinding conductive upper

CZ. 30 226

surfaces are created, the mantle and floor by a corresponding Connect the laminate to one another in a conductive manner and provide electrical conductivity between the grid and the surrounding soil produce. The spatial shape claimed here is based on the example of a transparent GRP storage tank for storing flammable liquids of group A (hazard classes I and II) and B in j5 drawings and is described in more detail below:

Figure 1 shows the transparent GRP tank, Figure 2 shows the connection between the bottom and the cylinder in the

Cut,
Figure 3 shows another way of connecting ground /

Cylinder in section.

The tank consists of a section 1 (FIG. 1) which is usually cylindrical in cross-section and is produced, for example, by the winding process, two floors 2 that are laminated or glued on, for example, produced by the pressing process, and one electr. conductive manhole socket ^. The winding section and the base are transparent and contain conductive grids 4 which are conductively connected by a laminate 5 at the cylinder / base butt joints. The manhole connector is connected to the laminate 5 by an electrically conductive laminate 6 or another conductor.

χ The winding shot consists of a reaction resin, such as an un- l ·

saturated polyester (UP) resin as matrix and reinforcing fibers., e.g. fiberglass. After the first layer of glass silk mat, fleece or the like 7 (Figure 2), a conductive grid 4 is placed at a distance inserted from 0.2 to a maximum of 2 mm from the inner surface This conductive grid protrudes a few cm at the ends of the shot. The further construction of the winding section takes place in in the usual way e.g. by Hoving winding layers 8 alternating with flat glass fiber reinforcements 9-

In the case of the bottom 2 (FIG. 2), the conductive grid can be made of process engineering As a rule, reasons are not given, as is the case with the vetch Protrude from the edge. Therefore, in its production, e.g. in the

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PreSverfahr-en, one to e: ws 40 approx wide strips of eiaetn conductive, voluminous fleece, z-3. Metal fleece, on the upper hand of the preform! ing o.a .. outside so inserted that about one half of the fleece on the preform is IC and the other half ICa and ICc protrude beyond the hand. In the. Deformation o.a. is the conductive grid 4 placed and the protruding edge of the fleece ICa and b so too ?! 3odeninner folded that the conductive ICb comes to lie directly on the grid. The grid will on the inside with a glass fleece, a glass mat or the like, 11 like this covered so that the grille is max. 2 mm below the inner upper

treatment can now be sanded at the edge without affecting the conductivity is lost from the inside grille to the outside.

The assembly of the base and container closure takes place so that the protruding Grate at the end of the shot is turned 4a and the floor, if required, with a conductive adhesive 12 on the butt edge, is set butt against the winding weft. Eir. conductive laminate 5 connects the bottom and the wrapped weft in a tight fit. The ones from Laminate covered surface must be ground beforehand.

Similar to the production of the floor, instead of a protruding Lattice 4a a voluminous, conductive fleece between 7 and 4 according to FIG survives. Before the last outer laminate layer, the fleece is folded over 1 ^ a and the last laminate layer is applied. Before assembly The ends of the winding section are sanded to the cylinder. In this way the conductive surface is restored. The further assembly takes place as already described in the example of FIG.

Claims (4)

«· A · e α 7- Ο.Ζ. 30 226 protection claims 1. Transparent storage container for above or below ground storage of flammable liquids, which has a conductive connection between the conductive floor and cylinder grid or nonwoven inlays, characterized in that a possibly covered by further laminate layers voluminous conductive fleece on the edge of the conductive grid to the next surface is arranged so that an electrically conductive connection between the grid insert and tank surface is present via a plurality of fibers of the voluminous conductive fleece. and the bottom and the shell of the transparent tank are connected to one another by an outer, conductive laminate. 2. Transparent container according to claim i, characterized in that graphitized synthetic fiber sheet-like structures are used s.ls Jiitbaren grid. J>. Transparent storage container according to claim 1, characterized in that a metal fleece is used as the conductive, voluminous fleece. 4. A transparent storage container according to claim 1, the bottoms of which are connected to the container jacket by a conductive laminate, characterized in that graphitized glass fleece, graphitized glass mats and / or fabrics are used as reinforcing fibers. Sign. BASF Aktiengesellschaft