GB2177138A - Fire resistant structural components - Google Patents

Abstract

Constructional components are described which are useful in the construction of fireproof or fire resistant enclosures using a modular construction system. In particular, the invention discloses components consisting of a framework of bars 1 with exterior cladding 8 and 9 and interior insulation 10-17 which may be assembled together or on a suitable framework, and which have gaskets 20 and 21 at their edges which, when the components are assembled, are compressed to provide an efficient seal resistant to fire. The components are of particular value in constructing enclosures in hazardous industries such as the oil and gas industry. <IMAGE>

Description

SPECIFICATION Structural components This invention relates to structural components, and particularly to such components useful for the manufacture, in modular fashion, of fire resistant structures.

In many industries, particularly in the oil and natural gas industries, the need for fireproof or fire resistant structures arises. These can be enclosures surrounding equipment which would be hazardous if not enclosed, or structures such as control rooms or laboratories or can be acommodation units. Size may vary from e.g. a 1 metre cube to e.g. 10 X 4 X 2 metres or even larger.

Particularly in remote environments, either on land or offshore, such as are encountered in the oil and gas industries, there is a desire to make the assembly of such enclosures simple and straightforward, and in particular that the construction of such enclosures is not itself hazardous. Thus it is clearly undesirable to have to engage in conventional construction technigues e.g. welding or cutting if that would itself create a hazard.

The way of solving this problem is to form such enclosures from a number of pre-formed constructional units, conveniently formed as a set of frames and panels which, when assembled, constitute the desired enclosure.

A difficulty with such an approach is the tendency of fire to penetrate gaps between panels if a modular system is used. Clearly structures may be assembled and all gaps then sealed e.g. using an external or internally applied sealing materials or the like, or pretal panels may be welded together, but such post-construction techniques are time-consuming to effect, some are unreliable in practice, and some techniques lack durability especially in adverse environmental conditions.

According to a first feature of the present invention, there is provided a structural component useful in the construction of modular enclosure structures of the type indicated above, and which consists of a hollow flat frame, a thermally and/or fire resistant panel on each side of the frame and generally coextensive therewith, at least one compressible gasket around the edges of the panel, a thermally resistant and/or fire resistant filler material located between the panels and within the frame, and the cross-section of the external edges of the frame being of a generally stepped, rebated or grooved configuration, the frame being provided at a plurality of locations about its periphery with engagement means adapted to cooperate and engage with appropriate formations on an adjacent component or on a frame member and to hold the component thereto with the gasket under compression.

Such components may be used in conjunction with frame members to build modular structures which, when completely assembled, are fire resistant and/or fireproof, and where the joints between the individual members are leak-proof on account of the presence in them of the compressed gaskets.

The design of individual components and of frame members for use therewith may of course vary widely. However, in any practical embodiment of the invention the components will almost invariably be rectangular, of a size which can conveniently be handled without difficulty by one or two men, and of a thickness and materials of construction adequate to the degree of fire proofing or fire resistance desired for the particular application.

The components are constructed on the basis of a flat frame. This is conveniently formed of a plurality of steel sections welded together in an appropriate rectangular shape, either as a simple open frame or as a frame with suitable crossbracing. The frame preferably has affixed to it, at a plurality of locations about its periphery, engagement means. The preferred engagement means are camlocks, conveniently formed of metal components throughout and welded to the frame.

The panels on either side of the frame may be selected from any appropriate material, but are preferably metal, most preferably steel sheets. They may be flat or e.g. ribbed or corrugated.

The exterior panels may lie directly adjacent the frame or they may be spaced therefrom e.g. by a suitably configured metal strip attached both to the frame and to the panel.

The depth of the frame i.e. its dimension measured normal to the plane of the panel, may in such a case be a relatively minor proportion of the overall thickness of the finished component. If of metal, the panel member may conveniently be welded to the frame.

Other methods of fixing may also be used.

The panel members may also be composite, for example a laminate of a fire resistant nonmetallic material with a metal or fire ignition resistant plastics facing thereon. Panels may have a suitable decorative finish.

The interior of the component is filled with a filling of thermally resistant and/or fire resistant filler material. Preferably this is a relatively light weight material of an inorganic fibrous nature, for example asbestos (not preferred due to the health hazard) or an appropriate ceramic or mineral fibre. Rockwool is particularly suited to the purpose, and this is conveniently used in the form of cut sections which may be laid inside the frame and which may fill the interior of the overali unit.

It is particularly preferred to use such fibrous insulation material in the form of a plurality of layers with one or more pieces of metallic mesh or sheeting located between the layers. The mesh or sheeting is desirably configured to interact with the layers of fibrous material so as to prevent or minimise movement of one relative to the other in a plane parallel to the plane of the mesh or sheet.

This prevents or minimises any slumping of the installation material when the overall component is located in a generally vertical plane, which slumping could materially reduce the effectiveness of the component as a fire barrier.

It is particularly preferred to use a metal mesh and furthermore to use one in which individual members forming the mesh have been cut at a plurality of locations over the area of the mesh with the free end or ends of a wire or like member thereby created being bent out such that pins or spikes project to either side of the plane of the mesh. These pins or spikes penetrate the fibrous insulation material and prevent movement of one relative to the other. Spikes or projections may be formed by stamping from a metal sheet or they may be provided in any other convenient way.

The edges of each component are provided with compressible gaskets. These compressible gaskets preferably take the form of a bead of fibrous inorganic material in the form of a strand or rope surrounded by a strip of inorganic fibre fabric, the strip being folded around the bead and the two edges of the strip brought together and affixed to the structure of the component. Such gaskets are fire resistant, easy to manufacture, and provide, when compressed between adjacent components or between the component and a frame member to which the component is attached, an effective fireproof seal capable of accommodating movement caused by thermal distrain of the units as a whole in the case of a fire. The edges of each component may have one or more such gaskets, the gaskets being of identical or varying construction.

The preferred mode of attachment of the components in position is by the use of camlocks. Camlocks are well known standard locking units and they consist of a housing having in it a rotatable hook which can be retracted toward the housing by rotating an actuation member in one direction or which may be caused to move away from the housing by rotation thereof in the opposite direction.When projecting from the housing, if the rotation of the hook itself is prevented, as by engagement over an appropriate pin or lug, continued rotation of a central actuation member set in the hook and mounted eccentrically relative thereto causes the hook to move translationally back towards the housing and accordingly to pull the pin, lug or the like towards the housing, thus, in the case of the components of the present invention, compressing the gasket on the edge of the component as the adjacent component or intermediate frame member is drawn towards the component by rotation of the actuation member of the camlock.

By using camlocks in this way it is possible to produce a modular construction system consisting of a set of components and a framework which can be assembled together very simply by the use of a single tool adapted to engage and rotate the actuation number of the individual camlocks. Such assembly methods are of particular value not only because they allow structures to be assembled with speed, but because they allow structures to be assembled using relatively unskilled labour and without resorting to potentially hazardous operations such as welding.

As noted above, the edges of the components may be stepped, grooved or rebated.

Appropriate constructions may be used to provide a tortuous path across each joint between the component and its adjacent component or a frame member, thus providing an added degree of fireproofing by providing a long fire-path. For many joints between components or between components and frame members, grooved edges are preferred, as these produce tortuous joints with high structural stability. Two grooved members may engage a suitable elongate frame member located between them and in such a case two adjacent components may effectively close round a frame member further protecting it from fire and giving a satisfactorily consolidated structure.Clearly, however, complete enclosures cannot geometrically be constructed in that way, and it is necessary in many cases to provide at least one unit and often several units with stepped edges enabling them to be inserted and removed relative to the remainder of the final structure, simply by moving in a direction normal to their main plane. Access panels should of course be constructed in this way.

It is of course possible within the context of the construction of a full enclosure using components in accordance with the present invention to provide individual components with appropriate special features, e.g. connectors enabling the provision of services to the interior of an enclosure, e.g of an electrical, pneumatic or hydraulic nature, or air conditioning, and it may on occasion be desirable e.g. to incorporate a window. This can be done using normal techniques and without affecting the basic construction of the individual components. An emergency escape hatch or door of conventional construction may also be incorporated.

The invention is illustrated by way of example with reference to the accompanying drawings in which: Figure 1 is a perspective, part cut-away view of a typical unit in accordance with the invention showing various components thereof; Figure 2 is a crosssection through a joint between two panels of the type generally shown in Figure 1, showing how they may be attached to a framework member; Figure 3 is a section similar to Figure 2 but showing an alternative; Figure 4 is a section showing the attachment of two panels to a corner post forming part of an enclosure structure; and Figure 5 shows in section a joint between a ceiling and a wall panel via a frame member.

Referring to Figure 1 the unit shown there is based on a frame formed of a number of hollow square section steel bars 1, welded together to provide a generally rectangular frame with cross bracing.

Welded into parts of the frame are a series of camlocks 2, only which of one is shown in Figure 1, and which consist of a generally rectangular housing having an actuating shaft 3.

Shaft 3 projects to one side (downwardly as shown in Figure 1) and can be operated using a suitable tool.

In the part cut-away unit shown in Figure 1, the access apertures cut in the other components to enable access to shaft 3 are not shown, but they are of course there in the complete unit.

Welded to the exterior edges of frame 1 are four generally squared "S"-section steel strips 5 which constitute the main edge members of the unit. The four members are mitred at the four corners of the unit and present upper and lower flanges 6 and 7 respectively, to which external cladding sheets 8 and 9 respectively are attached. Conveniently sheet 8 is a sheet of steel with pressed ribs for strengthening which is attached to flange 6 by welding.

Sheet 9 is a sheet of metal faced marine board, the board being bolted on to flange 7.

The interior of the unit shown is filled with three layers of inorganic fibrous insulating material, e.g. rockwool and these are denoted 10, 11 and 12 on Figure 1. The layers are cut to fit around the individual pieces of the frame and the camlocks 2, and they are sized such that they completely fill the interior space.

More or fewer layers may be used, as desired.

Between layers 11 and 12 there is located a rectangular metal wire mesh 15, individual portions of which have been cut and bent out, such as at 17 and 18, so that, as shown in Figure 1, they project upwardly or downwardly and these penetrate into the layers 11 and 12 of rockwool respectively. Mesh 15 thus holds layers 11 and 12 from slumping, even if the component is installed in a vertical plane and it is subjected to vibration. More importantly, even if the component is attacked by heat, such as in the case of a fire, the mesh 15 acts to delay any slumping of the insulation material and accordingly to prolong the fire resistance of the component.

Mounted at the edge of each strip 5 are a pair of compressible gasket members 20, 21 each of which is in the form of a bead of fibre held in a tape of woven inorganic fibre.

The tape is wound right round the bead and both edges of the tape are riveted together and to and through the member 5, e.g. by pop rivetting through suitable holes provided along the edge of member 5.

The unit shown in Figure 1 is normally used with its upper most surface, panel 8, outwards e.g. on the exterior of an enclosure formed from such units. The camlocks 2 are operated from the interior of the enclosure. In the case of small enclosures, for example housings for pipework, cables or the like, it will generally be desired to be able to operate the camlocks from the exterior of the housing and in those cases a suitable aperture to allow actuation of shaft 3 may extend through layer 10 and sheet 8. It may be closed e.g.

against ingress of water, using a suitable closure cap.

Figures 2 to 5 show sections through joints in frameworks constructed using units as in Figure 1 or modified units where the edge of the panel is stepped rather than grooved.

In those figures, the same reference numerals are used to identify similar parts as are shown in Figure 1. The units are assembled onto frame members 60 in Figure 2 and 50 in Figure 3. In both cases, these frame members consist of steel sections filled with appropriate heat insulating material 55 (e.g. rockwool) and where the individual steel sections have slots 56 and tranverse pins 57 associated with those slots. During assembly of the units onto the frame members, the hooked levers of the camlocks, denoted 70, rotate, pass into the slots, the hook ends engage over the pins 57, and continued rotation of the shaft 3 in each case causes the hook to retract back in towards the main body of the unit in which the camlock is mounted thus pulling the entire component towards the frame member 50 or 60 respectively, and compressing the gaskets 20 and 21 together or against the frame member.In Figure 3, gasket 20 is a doublebead type, the outer surface of which is adapted to be water-repellent e.g. formed from a pan of inorganic fibre ropes surrounded by a casing of neoprene impregnated fabric.

As shown in Figures 2 and 3, fire resistance is additionally enhanced by the presence of a metal strip 80 welded along one edge of the exterior cladding.

Figure 4 shows a square steel section cornerpost 82 with external cladding 81, the interspace between cladding 81 and post 82 being filled with rockwool 83.

The joint system of Figure 3 enables a component to be removed from an assembly of such components in a direction normal to the plane of the panels, as the edge members, denoted 30, are stepped and not of S-section.

Frame member 50 has a steel sheet 35 and marine board cladding 36 on it to complete the joint. Cladding 36 has access holes 37 to enable actuation shafts 3 of camlocks 2 to be operated.

Referring to Figure 5, this shows- in exploded form a vertical section through a horizontal beam at the top edge of an enclosure and parts of a ceiling and wall panel adjacent thereto.

The horizontal beam consists of a square steel section 90 to which are welded two smaller square steel sections 91 and 92 which are provided with slots 56 and pins 57 to cooperate with hooked levers 70. The interior of sections 90, 91 and 92 is filled in each case with rockwool.

Attached to section 90 is a metal cover 94 configured to provide a downwardly depending drip rail 95 and an upwardly open gutter or gully 96. The interspaces 97 are filled with rockwool. A compressable neoprene gasket 98 is provided to ensure a weatherproof seal between the ceiling panel and the horizontal beam.

Claims (14)

1. A structural component which consists of a hollow flat frame, a thermally and/or fire resistant panel on each side of the frame and generally co-extensive therewith, at least one compressible gasket around the edges of the panel, a thermally resistant and/or fire resistant filler material located between the panels and within the frame, and the cross-section of the external edges of the frame being of a generally stepped, rebated or grooved configuration, the frame being provided at a plurality of locations about its periphery with engagement means adapted to cooperate and engage with appropriate formations on an adjacent component or on a frame member and to hold the component thereto with the gasket under compression.

2. A component according to claim 1 and which is rectangular, of a size which can conveniently be handled without difficulty by one or two men.

3. A component acording to claim 1 or 2 wherein the flat frame is formed of a plurality of steel sections welded together to form a frame.

4. A component according to any one of claims 1 to 3 wherein the frame has affixed to it, at a plurality of locations about its periphery, engagement means.

5. A component according to claim 4 wherein the engagement means are camlocks welded to the frame.

6. A component according to any one of claims 1 to 5 wherein the panels on either side of the frame include steel sheets.

7. A component according to any one of claims 1 to 6 wherein the interior of the component is filled with a filling of thermally resistant or fire resistant lightweight inorganic fibre filler material.

8. A component according to claim 7 wherein the lightweight inorganic fibre filler is in the form of a plurality of layers with metallic mesh or sheeting located between at least some of them.

9. A component according to claim 8 wherein the mesh or sheeting is configured to interact with the layers of fibrous material so as to prevent or minimise movement of one relative to the other in a plane parallel to the plane of the mesh or sheeting.

10. A component according to claim 9 with a metallic mesh is located between two layers of inorganic fibrous material, wherein individual members forming the mesh have been cut at a plurality of locations over the area of the mesh with the free end or ends of a wire or like member thereby created being bent out such that pins or spikes project to either side of the plane of the mesh and penetrate the fibrous insulation material.

11. A component according to any one of claims 1 to 10 wherein the compressible gaskets include a bead of fibrous inorganic material.

12. A component according to claim 11 wherein the bead is in the form of a strand or rope of fibrous inorganic material surrounded by a strip of inorganic fibre fabric, the strip being folded around the bead and the two edges of the strip being brought together and affixed to the structure of the component.

13. A structural component substantially as hereinbefore desribed with reference to the accompanying drawings.

14. An enclosure formed of a plurality of structural components according to any one of the preceding claims and a set of elongate frame members linked together directly or via such structural components and to which the structural components are attached by the engagement means thereof.