GB2166120A

GB2166120A - Linings

Info

Publication number: GB2166120A
Application number: GB08423372A
Authority: GB
Inventors: Henry Stanley Rhodes; Richard Michael Hunt
Original assignee: YEATE AND HANSON IND Ltd
Current assignee: YEATE AND HANSON IND Ltd
Priority date: 1984-09-15
Filing date: 1984-09-15
Publication date: 1986-04-30
Also published as: GB8423372D0

Abstract

A cladding or lining member (2), e.g. a tile, is formed of abrasion and/or corrosion resistant material and includes a protruding bolt (9) for securing the member to a surface, so that the member and adjacent members similarly secured to the surface provide the surface with abrasion and/or corrosion resistance. The member has gaskets (5) (7) of resilient material secured thereto so that when the member is bolted to the surface, the gasket substantially prevents any liquids which pass between adjacent members from contacting the surface. <IMAGE>

Description

SPECIFICATION Abrasion and/or corrosion resistant cladding/ lining materials This invention relates to abrasion and/or corrosion resistant cladding/lining materials, The need to cover surfaces with cladding or lining materials to provide protection against abrasion and/or corrosion arises in many fields such as mining, quarrying, mineral processing, chemical engineering, civil engineering, farming and aerospace fields. In such fields there are many instances where equipment is used in an environment where it is subjected to abrasion and/or corrosion.

In some cases, protection against abrasion and/or corrosion can be achieved by fabricating the appropriate parts of the equipment from abrasion and/or corrosion resistant material. However, this is not always possible because of the cost of the material and/or because the material has other properties which render it unsuitable and/or because of difficulties in fabricating the equipment from the material.

It is also known to produce abrasion and/or corrosion resistant cladding material by providing a substrate in the form of a rolled steel piate or a steel fabricated component and applying hard metal or alloys to the substrate by such processes as spraying, sintering or welding. However, such materials are frequently not as resistant to wear as would be expected.

Additionally, it is known to provide surfaces, such as the surfaces of mineral conveying chutes, with resistance to abrasion and/or corrosion by cladding them with abrasion and/ or corrosion resistant materials. For example, tile-like members formed of ceramic material (e.g. ordinary quarry tiles or high alumina tiles) or formed of metal alloy may be secured on site to the surfaces using bolts or cementitous adhesives. However, when bolts are used, the tile like members will not protect the surface from the ingress of liquids unless they are grouted or provided with some other sealing material such as by inserting sheets between the members and the surface during the cladding operation. However, such procedures are time-consuming, frequently difficult to carry out and subject to omission or error.

It is an object of the present invention to avoid these disadvantages.

According to present invention there is provided a cladding material which comprises a member formed of abrasion and/or corrosion resistant material and including a protruding bolt for securing the member to a surface so that the member and adjacent members similarly secured to the surface provide the surface with abrasion and/or corrosion resistance, the member having a gasket of resilient material secured thereto so that when the member is bolted to the surface, the gasket substantially prevents any liquids which pass between adjacent members from contacting the surface.

The member may be in the form of a tile, block or other article and the resilient material will generally be formed of an elastomer selected so as to be resistant to the liquid likely to be encountered by the cladding material in use. The gasket may be of any suitable crosssection such as triangular, rectangular or circular.

In the manufacture of the cladding material that part of the surface of the member to which the gasket is to be secured should first be cleaned and then be prepared as necessary so that the gasket can be adequately secured to the member. Then the gasket may be formed in situ on the member by extruding the resilient material through a nozzle of appropriate configuration and depositing it onto the cleaned and prepared part of the member.

The gasket may be secured to the member by means of an adhesive, as a consequence of it being located in a groove in the member, or it may be self-adhesive and extruded directly on to the members. The adhesives may be, for example, one of the acrylic-based materials marketed by Bostik Limited under the name Bostik Reactive Bonding Systems (The word "Bostik" is a Trade Mark).

In use of the cladding material, it is merely bolted to the surface to be protected in the conventional way. The gasket becomes compressed between the member and the surface and provides a fluid tight seal to prevent liquids which may pass between adjacent members in use from contacting the surface and having a deleterious effect thereon. The presence of the gasket also improves the impact resistance of the member, accommodates irregularities in the surface to be clad and inhibits transmission of noise.

The cladding material can be used in any situation where abrasion and/or corrosion resistance are to be provided and, particularly, in circumstances where liquids are likely to be present. Thus, for example, the cladding material may be applied to the surfaces of equipment such as tanks, vessels, bunkers, chutes, launders, troughs, scraper conveyors, wearing strips, wearing plates, pipes, cyclones, cutting edges on, for example earth moving buckets, plough shares, crushers, chopping machines, fan blades, centrifuge scrolls, worm conveyor flights and pump impellers for pumping suspensions or other abrasive materials.

The members are preferably in the form of tiles which advantageously are from 2 to 28 inches (50 to 700mm) in length and width and from 21 to 3 inches (12 to 76mm) in thickness. The member may be made of any abrasion and/or corrosion resistant material having regard to the purpose for which the cladding material is to be used. Advantageously the member is formed of white cast iron or other abrasion and/or corrosion resistant materials which cannot ordinarily be cast into large sheets. It is preferred for the member to be formed from the high chromium grade abrasion resisting white cast irons described in BS 4844 part 3 June 1974.Typically, these cast irons consist of from 2.2 to 3.6% carbon, no more than 1.5 silicon, up to 1.5% manganese, from 17 to 28% chromium, up to 3.0% molybdenum, not more than 2.0% nickel, not more than 1.2% copper and not more than 0.1% phospherous. It is particularly preferred for the chromium content to be at least 27% in order to avoid brittleness.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 is an underneath plan view of cladding material in accordance with the present invention; Figure 2 is a cross-section along line ll-ll of Fig. 1 and Figures 3a to 3f correspond to the parts encircled in Fig. 2 and show alternative embodiments on a large scale.

Referring to Figs. 1 and 2, which are not to scale, the cladding material is generally denoted by reference numeral 1 and comprises a square tile 2 having a central boss 3 and a thickened peripheral portion 4. An annular gasket 5 formed of an elastomeric material is secured to the peripheral portion of the end face 6 of the boss 3. A square gasket 7 similarly formed of an elastomeric material is secured to the end face 8 of the peripheral portion 4. The head of a bolt 9 is embedded in the boss 3 so that the threaded portion 10 of the bolt protrudes beyond the end faces 6 and 8.

The tile is formed by appropriately casting a high chromium grade abrasion and corrosion resisting white cast iron containing 2.8% carbon, no more than 1.0% silicon, 1.0% manganese, 27% chromium, 1.0% molybdenum, 0.5% nickel, 0.6% copper, and less than 0. 1?/o phosphorous, the remainder being iron.

In use, the cladding material is affixed to the surface to be protected by passing the bolt through an aperture in the surface and threading a nut onto the bolt. On tightening the nut, the gaskets deform as necessary between the surface and the tile to accommodate any irregularities in the surface and form a fluid tight seal thus preventing ingress of liquid between the surface and the tile when the cladding material is used in an environment in which it is likely to encounter liquids.

Referring now to Fig. 3a, there is shown an embodiment where the edges 11 of the end faces of the boss 3 and portion 4 are chamfered and the gaskets 5 and 7 are triangular in section and are adhered to the chamfered edges by means of an acrylic based Reactive Bonding System of Bostik Ltd comprising an acrylic adhesive known as Bostik M890 and a reacted amine known as Activator A. Bostik M890 is a viscous cloudy white liquid of viscosity 300 poise, specific gravity 1.02 and a flash point of 11"C (closed cup). Activator A is a pale brown liquid having a viscosity of 100 cps at 25"C. Alternatively they may be extruded directly on to the member, employing a self-adhesive material. Bostik M890 is one such material.

In Fig. 3b, the edges 11 of the end faces of the boss 3 and portion 4 are provided with rectangular sectioned grooves and the gaskets 5 and 7 are rectangular in section and may be extruded directly into the grooves or preformed and retained by adhesives.

Fig. 3c shows an embodiment where semicircular grooves 12 are provided in the end faces of the boss 3 and the portion 4. The gaskets 5 and 7 are circular in section and are self-adhesive extrusions or pre-formed and retained by adhesives.

Referring now to Fig. 3d, this embodiment is similar to that of Fig. 3a except that the chamfering of the edges 11 is more pronounced and the cross-section of the gaskets 5 and 7 is modified accordingly.

In accordance with the embodiment of Fig.

3e, the gaskets 5 and 7 are rectangular in section and are simply adhered to the edges 11 of the end faces of the boss 3 and the portion 4 by means of the aforementioned Bostik M 890/Activator A Reactive Bonding System.

In Fig. 3f, a part-circular sectioned groove is provided at the edges 11 of the end faces of the boss 3 and the portion 4. The gaskets 5 and 7 are circular in section and are held in the grooves as a consequence of direct extrusion of self-adhesive material or by adhesives in the case of pre-formed gaskets.

Claims

1. A cladding or lining material which com prises a member formed of abrasion and/or corrosion resistant material and including a protruding bolt for securing the member to a surface so that the member and adjacent members similarly secured to the surface pro vide the surface with abrasion and/or corro sion resistance, the member having a gasket of resilient material secured thereto so that when the member is bolted to the surface, the gasket substantially prevents any liquids which pass between adjacent members from contactEing the surface.

2. A material as claimed in claim 1 wherein the member is in the form of a tile.

3. A material as claimed in claim 1 or 2 wherein the member is formed of white cast iron.

4. A material as claimed in any preceding claim wherein the gasket is triangular, rectangular or circular in cross-section.

5. A material as claimed in any preceding claim wherein the resilient material is an elastomer.

6. A material as claimed in any preceding claim wherein the resilient material is self-adhesive.

7. A material as claimed in any one of claims 1 to 5 wherein the gasket is adhered to the member by a separate adhesive.

8. A material as claimed in any one of the preceding claims wherein the gasket is located in a groove in the member.

9. A cladding or lining material, substantially as hereinbefore described with reference to the accompanying drawings.