NO162736B - Insulation element, especially for stoves and boilers, AND PROCEDURE FOR AA ISOLATING A OVEN AREA. - Google Patents

Description

The invention relates to insulation, as well as its installation. The invention relates in particular to an insulation element which can be used to insulate a surface, a method for mounting the insulation on a surface, and fixing means for fixing the insulation to a surface. The invention is more specifically aimed at a heat-resistant insulation element that can be used to insulate an oven surface and the application of heat-resistant insulation in an oven or boiler (hereinafter referred to as an oven) to insulate a wall surface in the oven.

It is well known that it causes problems to insulate the inner surfaces of the walls (comprising walls, roof, inner door surfaces and other oven surfaces to be insulated) in an oven. The interior of high-temperature furnaces has historically been lined with different types of bricks capable of withstanding high temperatures. When such brick linings wear out, it is tedious and time-consuming work to replace the old bricks with a new brick lining.

The disadvantages of brick linings, combined with the need for more efficient and more heat-resistant linings, have led to the use of insulating fiber materials that serve as insulation or at least as insulation for the hottest surfaces.

Ceramic fiber materials, as will be shown here,

are generally available in the form of a ceramic fiber mat which is usually manufactured in processes similar to conventional paper manufacturing processes. Thereby, the fibers that form mats will be oriented in planes that are mainly parallel to the longitudinal direction (forward direction) during the production of the mat or web.

If sections are cut from such a web to form mats or sheets and applied as such to an inner furnace surface,

the mat or plate will lie in a plane mainly parallel to the surface on which the mat or plate is fixed.

When such mats are applied to a furnace surface, the main part of the fibers of the ceramic material will lie in a direction mainly in the direction of advancement of the web during its manufacture, although a significant number of fibers will have a more or less random orientation. When the fibers lie in planes that are parallel to the oven wall, there is a general tendency for the fiber mat material to crack, as this is a result of heat shrinkage.

When ceramic fiber insulation in mat form is used, the high ambient temperature will also lead to vitrification and cracking and layer separation problems.

Attempts have been made to overcome the aforementioned problems by using ceramic fibers in mat form by cutting fiber strips from a mat produced in this way across the direction of advance during the production of the web.

These strips are cut from the fiber web in widths corresponding to the linear thickness from the cold side to the hot side surface of the insulating fiber mat. The cut strips are then placed on the cut edge and laid lengthwise in a side-to-side relationship, using such a large number of strips that a mat of the desired width is obtained.

The thickness of the fiber web from which these strips are cut will of course determine the number of strips required to build up a mat of the desired width.

When installing such strips on the inner surface of the oven where the fibers in the ceramic fiber material extend mainly perpendicular to this surface, the vitrification, layer separation, shrinkage and cracking problems will be significantly reduced.

Furthermore, since ceramic fiber materials tend to be compressible (or at least compressible with a limited degree of compliance), the strips can be arranged butted against each other, thereby avoiding the formation of gaps between neighboring strips due to shrinkage during use.

Whether the insulation material is used in web or strip form, some suitable means is required to attach the insulation material to an inner surface of a furnace wall. Different methods have been tried for this purpose. If it e.g. if insulation materials are used in web form, studs or bolts can be welded to a furnace wall in advance,

and the insulation material can then be inserted onto the bolts or studs and fixed in place using nuts or the like.

This method is disadvantageous because bolts or studs must be arranged in advance on the furnace wall according to a special plan. This entails the disadvantage that the position of the bolts or pins cannot be easily changed when this is necessary. Because the bolts or studs extend through the insulation material, they will also be exposed to the temperature inside the oven and will conduct heat directly from the oven space to the oven walls. This is not only a waste of heat, but it also leads to undesirable hot spots in the oven walls.

When insulating material in strip form is used, the strips can be attached to the oven walls using pre-welded brackets on the oven walls, where the strips are attached to the brackets using threads or the like that extend through the fiber strips. This will again entail the disadvantage that the brackets must be welded in advance according to a special pattern which makes repositioning impossible or impractical. This entails the further disadvantage that the handling of the strips becomes tedious and labor-intensive.

In order to overcome these disadvantages, attempts have been made to attach the insulating material to a furnace wall by mounting the insulating material on rigid blocks of ceramic material or on carrier plates or panels that form modules. The modules can then be handled separately and can be mounted on the oven wall by attaching the blocks, plates or panels to the oven wall.

Although this modular design entails a number of advantages, problems still arise with effective mounting of the insulation material on the rigid blocks, plates or panels, depending on how these are present. When the substrate is in the form of a rigid block, the fibers can be attached to the substrate by threading threads or rods through the insulation material and then attaching the threads or rods to the substrate using fastening threads or the like at regular intervals. However, this solution is cumbersome and expensive. It is also not particularly effective when the substrate material is in the form of smaller ones

rigid plate material.

The so far proposed and most promising solution has been to mount the insulation material on a base plate by using a temperature-resistant adhesive. This solution has produced a relatively successful result for many applications. However, in furnaces operated in a sulphurous environment or where sulphurous fuels are used, corrosive liquids are formed

(which usually contain sulfur and/or sulphurous acids)

on the inner walls of the oven. As far as is known, the available adhesives or ceramic cement types are not able to withstand the effects of such corrosive liquids over a long period of time. The adhesive or the cement will therefore have a tendency to fail, and this results in the modules being destroyed prematurely by the insulation material being separated from the base plate earth and thereby from the oven wall.

When the insulating material is also combined with iron, the sulfuric acid or the sulphur-containing acid will react with the iron and form iron sulphates. It has now been found that these iron sulphates have a very corrosive effect on ceramic fibres.

When ceramic fiber insulation mats are to be attached to a furnace wall using a temperature-resistant adhesive or cement, ironically, the temperature gradient across the mat will not usually cause sulfuric or sulphurous acid to form, except near the cold side of the mat. This means that it is only near the cold side of the mat that the temperature is so low that sulfuric acid and/or sulphurous acid can form. It is therefore in this specific zone where the insulation system is most vulnerable, that the corrosive acids form (and which are formed when sulfur-containing fuel is used). In the most vulnerable area, namely at the furnace mantle or at a base plate, there is metal that is corroded by the acid in the interface zone between the insulation material and the mantle, where iron sulfates are produced that corrode the ceramic fibers.

The lifetime of such insulation is therefore limited, because the adhesive or cement is destroyed, and/or the ceramic fibers that are in intimate contact with the adhesive or cement that serve to attach the insulation mat to the base plate or furnace jacket, will be exposed to corrosive effects -thing. The fibers will therefore tend to fail near the adhesive or cement layer after a period of use. This double failure in the critical zone will eventually lead to failure of the insulation system.

It is therefore an object of the invention to provide a method for attaching insulation to a surface and an insulation element intended to be attached to a surface, thereby reducing or overcoming the disadvantages of the previously known

procedures.

It is assumed that due to the heating effect, heated air will tend to rise and create an overpressure in the upper area of the oven. This excess pressure will result in air flowing outwards through the insulation lining on the walls of the oven.

Since in most furnace insulation systems, significant air gaps occur between the insulation material and the furnace jacket, it is further assumed that this air flow will result in an unwanted heat loss. It is further assumed that this air flow will tend to increase corrosion in the interface zone.

Even if the previously known insulating materials are fixedly mounted on a furnace wall or furnace mantle, the mantle will tend to bend under temperature variations in the wall. The sheath areas can therefore be changed from a concave to a convex shape, etc. Even if the previously known insulation materials or modules are firmly attached to the sheath rafts, gaps will therefore still be able to form during bending of the sheath.

It is therefore believed that for many applications it will be advantageous to provide an insulating material which is firmly attached to the furnace wall surface or the mantle rafts and which will essentially remain in contact with these surfaces despite bending in the mantle due to temperature variations.

The characteristic features of the insulation element according to the present invention and the method for its production appear from the attached patent claims.

Although the principles of this invention can be used to mount insulation material on baseboards that can be used both as general insulation and as furnace insulation,

the invention is particularly aimed at insulation on inner oven walls in high-temperature ovens. In terms of the present invention, "high temperature" will mean a temperature above 870°C and preferably in the range from about 870°C to about 1540°C or higher.

When further in the description reference is made to oven walls, this shall mean all oven surfaces where insulation is required, extensive roofs, doors and the like.

Ceramic fiber insulating materials are commercially available from several manufacturers and are well known to those of ordinary skill in the art. Ceramic fiber mats are thus e.g. manufactured under trade names

"Kaowool" (Babock and Wilcox), "Fiber-Frax" (Carborundum Company), "Lo-Con" (Carborundum Company), "Cero-Felt" (Johns - Manville Corp.) and "Saffil" (I.C.I.). Most of these ceramic fiber mats have a suggested maximum operating temperature of about 1260°C, but by exposing the fiber ends or fiber edges by reorienting the fiber strips, efficient operation up to about 1540°C can be provided, when a suitable fiber quality is used. This suitable quality can e.g. be SAFFIL aluminum oxide fibres.

According to a feature of the invention, an insulation element is provided for insulating a surface, where the insulation element strength comprises: (a) an insulation mat which with a cold side is mounted against such a surface and has an opposite hot side and consists of a deformable insulation material, and (b) fastening means for fastening the element to this surface, the fastening means comprising anchoring means which are placed in the mat at a distance from both the cold side and the hot side and set the fastening means in relation to the mat, as well as connection means which are connected to the anchoring means to attach the element to the said surface, and as the connecting means pass through a recess inward to the cold side towards the said surface when the connecting means are pressed against the said surface to be attached to it.

The insulation element according to the invention can take the form of a plate or strip. However, the insulation element according to the invention is preferably in the form of an insulation module or insulation block which is assembled side-by-side against corresponding modules or blocks to form an insulation cladding.

The insulation element can therefore suitably be present as a module with a rectangular or square shape. The thickness of the module will depend on the insulation properties of the insulation material and on the oven environment for which the insulation element is designed.

The insulating material in the mat may be any suitable insulating material which will provide the desired thermal insulation and which is at least partially deformable, preferably with at least some degree of compliance, so that the mat can be pressed into compliant contact with a furnace surface.

The insulation material can therefore e.g. consist of a fiber insulation material, such as a mineral fiber material, a heat-resistant fiber material or a ceramic fiber material. However, it should be pointed out that other suitable types of insulation materials can also be used provided that the material is at least partially deformable, so that the material in the mat can be pressed or pressed into contact with the surface to be insulated.

When the insulation material is a fibrous insulation material, the material for special applications according to the invention can be used in mat form where the fibers are arranged in the fiber planes which run mainly parallel to the surface to be insulated and when the insulation element is fixed on this surface.

However, this type of mat arrangement entails many disadvantages. In the now preferred embodiment of the invention and in the insulation of high temperature furnaces operated at temperatures above about 870°C, the fibrous insulation material is therefore preferably a material in which the fiber planes are arranged so as to extend perpendicularly to the cold side of the element where the fibers are random oriented in the fiber plans.

The fastening means can be displaceable in that part or all of these fastening means are made of a suitable yielding, deformable or pliable material.

In this embodiment of the invention, difficulties may arise at higher operating temperatures, unless the fasteners are made of a compliant deformable material that is able to withstand these high temperatures without losing compliance, and/or unless the fasteners are positioned so that they are protected against the temperature conditions where they lose their compliance.

In a preferred embodiment according to the invention, the fastening means can remain resiliently deformable in that they have a resiliently deformable part that lies close to the cold side of the mat or element during use. The thickness of the mat can in this way serve to protect the compliant deformable part from being overheated during use, thereby ensuring that the compliant deformable part will retain its compliant properties during use and which will maintain the pressure on the mat during use.

The fastening means can e.g. include anchoring means connected to the mat, and yoke-like means extend from the anchoring means and are intended to be attached to the surface to be insulated. In this embodiment of the invention, the yoke-like members preferably comprise or constitute the yielding deformable part of the fastening members.

The anchoring means can be any suitable means which can be connected to the insulation mat element according to the invention and which can then be attached to a surface to be insulated, so that the insulation element can be attached to this surface.

The anchoring bodies can e.g. consist of one or more elongated threads, rods or tubes arranged inside the mat. In an alternative example according to the invention, the anchoring means can be in the form of a grid arranged inside the mat. In yet another example according to the invention, the anchoring means can be in the form of an elongated, non-linear element, which is arranged inside the mat.

Although the anchoring members themselves can be compliantly deformable or bendable, the anchoring members should preferably be made of a rigid material so that the stresses applied to the anchoring members will be distributed over the entire anchoring member, so that this exerts a pressure effect on the material in the mat.

In a preferred embodiment according to the invention, the anchoring means can therefore comprise a series of anchoring tubes which are arranged at intervals across and extend through the mat in a plane that is essentially parallel to the cold side, so that any stress on the anchoring means is distributed throughout the mat .

When the mat has fiber planes that extend transversely or usually perpendicularly to the cold side, the anchoring tubes are preferably arranged so that they extend mainly parallel to the cold side, but transversely so that the fiber planes thereby cause an effective placement of the anchoring means inside the mat.

In an embodiment according to the invention, a reinforcing material can be arranged inside the mat to reinforce it in the area of the anchoring members, so that the pressure force exerted on the anchoring members during use is better distributed.

The reinforcement material can comprise a mesh structure, a deposit of an adhesive material or the like.

The yoke-like members may have any shape suitable for engagement with the anchoring members and suitable for attachment to a surface.

In an embodiment according to the invention, the yoke-like members can consist of a connecting branch which is connected to or engages with the anchoring members and extends towards the cold side, as well as a yielding deformable or displaceable attachment part, designed to be attached to the surface to be is insulated, or that the fastening part is shifted compliantly and thereby presses or forces the connecting branch and thus also the anchoring elements and the mat in the insulation element against the said surface.

In one embodiment, the yielding deformable attachment part can be in the form of a spring element or the like which provides the pressure or pressure effect. The fastening part can therefore e.g. have the shape of a coil spring, a leaf spring or the like.

In a preferred embodiment according to the invention, the yielding deformable attachment part can be in the form of an attachment bracket which extends across or perpendicular to the connecting branch.

In a currently preferred embodiment according to the invention, the yoke-like members comprise a pair of connecting branches which are connected to each other by means of a fastening latch, so that the yoke-like members in section form a channel shape where each connecting branch has a free end in engagement with or is connected to the anchoring members .

The fastening means are preferably arranged in such a way inside the mat that the yielding deformable part lies in a recess inwards towards the cold side of the mat. The yielding bendable part can then be shifted yieldingly out of the mat towards the surface to be insulated in order to be attached to it, and thereby the fastening means and thus also the mat will be pressed yieldingly against said surface during use.

The fastening means can comprise a fastening device which is used when fastening the fastening means to the surface to be insulated.

In an embodiment according to the invention, the fastening device can be a bore designed to receive a bolt, screw, a weldable pin or the like in order to fasten the fastening device to said surface.

The fastening device can be one with a continuous extension of the material in the yoke-like bodies. The fastening device can e.g. alternatively constitute a separate fastening device which is attached to the yoke-like members on the fastening members. The fastening device may comprise a fastening element, e.g. in the form of a weldable pin which is intended to stick into the mat, the weldable pin having a meltable part which passes through the bore in the fastening device. In this embodiment, the fastening device can comprise an arc screen which surrounds the meltable part of the weldable pin, so that this can be attached to a surface to be insulated by means of an internal weld.

The fixing means can further include impact means to press the fixing device against a surface to be insulated once the fixing device has been fixed to this surface. The influencing device can e.g. be a nut that must be threaded onto a pin, bolt or the like to pull the fastening device and thereby also the yielding deformable fastening part towards the surface to be insulated, and a yielding pressure effect is thus obtained.

The invention also applies to a method for mounting insulation on a surface, as the method consists in a mat of a deformable insulation material which has a cold side intended for contact with an oven surface and an opposite side, is attached to this surface by means of fastening means which are arranged at a distance from the hot side, and that the fastening means are displaced towards the oven surface, so that the cold side of the mat is pressed into contact with the oven surface.

The procedure preferably consists of the mat being pressed yieldingly in a conforming arrangement against the surface of the oven.

In a preferred embodiment according to the invention, the method consists in the pressure effect being maintained during use, so that during use the mat remains pressed in an adaptive fit against the oven surface despite bending in the oven surface due to temperature variations.

The method can consist of compliant deformable fasteners connected to the mat being attached to the oven wall and thereby attaching the mat to the oven wall surface, and the fasteners then being pressed compliantly against the surface in order to maintain a pressure contact between the mat and the oven wall surface.

The invention further relates to fastening means for attaching a mat of insulating material to a furnace surface, the fastening means comprising anchoring means which are arranged in the mat, and yoke-like means which extend from the anchoring means towards said surface and are intended to be attached to this, the fastening means being resiliently deformable to press the mat against this surface.

If the fastening means are rigid, the pressure effect will be caused by a compression or yielding compression of the material in the mat. If, on the other hand, the fastening means comprise a yielding deformable or displaceable part which is preferably constituted by the connection means, the pressure or pressure effect will then be provided by the yielding displacement of the connection means, or both by the yielding displacement of the connection means and by the compression or the yielding compression of the material in the mat.

The invention further comprises an insulation element for insulating an oven surface, where the element has a cold side which is intended for contact with the oven surface during use and has an opposite warm side and a number of side edges, and the element comprises a deformable mat of fibrous insulation material, as well as fastening means for to attach the mat to this furnace surface: (a) where the fibrous insulation material has fiber planes arranged so that they extend perpendicular to the plane of the hot side, the fibers of the fibrous material being randomly oriented in the fiber planes, and (b) where the fastening means comprising: (i) a series of elongate anchoring elements disposed within the mat and extending perpendicularly to the fiber planes at a distance from both the cold side and the hot side, and (ii) yoke-like members having a fastening arm and a series of connecting members extending from the mounting arm,

where each connecting arm has a free end portion which is connected to an anchoring element, and where the fastening arm forms a fastening zone which lies close to the cold side and lies at a distance inwards from the side edges of the element, and which is used to fasten the element to this oven surface.

A preferred feature of this embodiment of the invention is that the fastening zone is located centrally in the module, that the anchoring elements are arranged inside the mat and that the connecting arms are connected to the anchoring elements in such a way that when a fastening force is exerted against the fastening zone, it will be distributed generally or preferably rather evenly over the module to keep the mat in place on the oven surface during use.

The connecting arms may conveniently extend from opposite ends of the attachment arm.

In a preferred embodiment according to the invention, the fastening means comprise two or at least two anchoring elements at a lateral distance from each other, and the yoke-like means have, in section, mainly a channel shape.

In an example according to the invention, the connecting arms can form a continuous extension of the material in the fastening arm. Alternatively, the attachment arm may have a connecting arm which is hinged to its opposite ends.

In certain embodiments according to the invention, the insulation material in the mat can consist of a composite insulation material made up of a number of different types of insulation materials. In this embodiment according to the invention, a combination of high-temperature-resistant and lower-temperature-resistant insulation materials can be used to achieve the most economical and practically most resistant combinations for the special operating environments and temperature conditions.

Although the invention is particularly adapted and most effective for use as high-temperature insulation for ovens, it should be pointed out that the invention can just as easily find applications when mounting other types of insulation to surfaces where firm contact between the insulation material and the surface to be insulated is required or preferred. Such alternative uses of the invention are therefore within the scope of the invention. In the preferred embodiment of the invention, however, it will be used in high-temperature furnaces, since it is for this application that the previously known systems have major disadvantages and where the invention therefore has major advantages.

Embodiments of the invention will now be described by means of examples with reference to the accompanying drawings, where: Fig. 1 shows a schematic oblique view of an embodiment of an insulation module in accordance with the invention. Fig. 2 shows on a larger scale a fragmentary, schematic side view of the fastening means in the module according to fig. 1, which must be attached to a furnace wall or cladding surface using a protected bolting system. Fig. 3 shows a schematic oblique view of an alternative embodiment of a module in accordance with the invention. Fig. 4 shows a similar view of a module similar to that of fig. 3, with the exception that the fastening element is shown in place in the module. Fig. 5 and 6 show on a larger scale an elevation and a section laid along the line VI-VI in fig. 5 of the yoke-like members and the fastening members in the module according to fig. 4. Fig. 7 shows on a larger scale a schematic outline of the module according to fig. 4, which is attached to an oven lining surface. Fig. 8 shows a schematic floor plan of an alternative embodiment of a module in accordance with the invention. Fig. 9 schematically shows a ground plan seen from the underside of a further alternative embodiment of a module in accordance with the invention. Fig. 10 and 11 show an elevation resp. a bottom plan view of a further alternative embodiment of the yoke-like members. Fig. 12 shows a schematic end view of yet another further embodiment of a module in accordance with the invention. Fig. 13 shows an elevation of an alternative embodiment of a module in accordance with the invention. Fig. 14 shows a plan of the yoke-like bodies in the module according to fig. 13. Fig. 15 and 16, fig. 17 and 18, fig. 19 and 20 show alternating ground views and side views of further alternative embodiments of the yoke-like bodies in accordance with the invention. Fig. 21 and 22 show yet two further embodiments of the yoke-like bodies in accordance with the invention. Fig. 23 shows an elevation of an alternative embodiment of a composite module in accordance with the invention. Fig. 24 and 25 show a schematic side elevation resp. end elevation of yet another further embodiment of a module in accordance with the invention. Fig. 26 shows a schematic plan of the yoke-like bodies in the module according to fig. 24 and 25, and Fig. 27 shows a plan view from the underside of yet another alternative embodiment of a module in accordance with the invention.

Reference should now be made to fig. 1 and 2 in the drawings where the reference number 10.1 generally refers to a high temperature insulation module for the insulation of high temperature ovens. The module 10.1 comprises a deformable mat 12 of insulating material and fastening means 14.1 for attaching the mat 12 to an oven surface to be insulated. The fastening members 14.1 are resiliently deformable in order to press the mat 12 in a fitting arrangement against this oven surface.

The mat 12 has a cold side 16 which is intended to be placed against an oven wall or an oven lining which is insulated during use, and it has an opposite warm side 18 which is directed towards the interior of the oven during use.

The deformable mat 12 is preferably made of a ceramic fiber material where the fibers in the material are randomly oriented in the fiber plane 20, and where the fiber planes lie in a side-by-side relationship and extend from the cold side 16 to the hot side 18 and in a straight angle on these side surfaces.

With this particular arrangement of the fiber planes where the ceramic material strips are arranged so that the end surfaces of the fiber planes 20 are exposed, the deformable mat 12 will be resistant to delamination and will also be more resistant to peeling and cracking.

The natural flexibility of the ceramic fibers will also result in an effective cover for the fasteners and thereby hide them inside the mat. The fasteners will therefore be protected by the fibers against the heat in the oven.

The fastening member 14.1 consists of anchoring members 22 and yoke-like members 24.1. The anchoring means 22 comprise an elongated, rigid anchoring tube 26 which is placed inside the mat 12.

The anchoring tube 26 is preferably a rigid tube of ceramic material which extends from one side to the opposite side of the mat 12 and is at a distance from both the cold side 16 and the hot side 18.

In an embodiment according to the invention shown in the drawings, the anchoring pipe 26 is approximately 5 cm from the cold side 16.

The anchoring pipe 26 is so far from the hot side 18 that it is well protected against the heat in the oven, and thereby the yoke-like bodies 24.1 will also be protected against overheating during use.

The yoke-like bodies 24.1 consist of a connecting arm 28.1 and a yielding deformable fastening part in the form of a fastening arm 30.1.

Connecting arm; 28.1 has a hook formation 32 at the free end. The hook 32 grips the anchoring tube 26 and thereby connects the yoke-like members 24.1 to the anchoring members 22.

The fastening arm 30.1 extends from the opposite end of the connecting arm 28.1 and perpendicular to this, so that an L is essentially formed.

The yoke-like members 24.1 are made of such a material that it is corrosion-resistant and will at the same time be resiliently bendable in order thereby to provide resilient deformability of the fastening members 14.1.

The yoke-like bodies 24.1 are therefore and preferably produced by e.g. stainless steel, so they will resist corrosion and will be resiliently deformable.

In a preferred embodiment according to the invention, the yoke-like members 24.1 are made of a high-strength material, such as stainless steel of type A304. This is one of the 18-8 stainless steel types A304 which are high-strength materials and will be corrosion-resistant, and which with appropriate design and placement will remain yieldingly bendable in the desired zone during use.

The yoke-like members can, for example, be made from a rod with a diameter of approximately 9 mm. The anchoring pipes can e.g. is produced from an approximately 300 mm long ceramic tube which has an outer diameter of approximately 12 mm and an inner diameter of approximately 6 mm.

The thickness of the mat 12 between the hot side 18 and the cold side 16 will of course be independent of the operating environment in the oven, where the module 10.1 is to be used. The thickness will therefore typically be at least about 75 mm, and it may vary between about 75 mm and about 150 mm or more.

In order to obtain a suitable heat protection for the anchoring pipe 26 and still ensure that there remains enough ceramic fiber material between this and the cold side 16 to provide an effective yielding compression of the material in the mat 12, the pipe 26 is suitably placed, so that it lies approximately 50 mm within the cold side 16. However, it should be pointed out that this distance can vary depending on the operating environment in the oven for which the module 10.i is designed, on the type of material from which the mat 12 is made, on the thermal conductivity of and material properties the cabinets in the yoke-like bodies and to what extent it is necessary to compress the material in the mat.

The yoke-like members 24.1 are in engagement with the anchoring tube 26 and extend from this in the direction towards the cold side 16. The fastening arm 30.1 extends perpendicularly to the connecting arm 28.1 and lies mainly in the same plane as the cold side 16.

However, the fastening arm 30.1 lies in a groove within the cold side 16, so that the yoke-like members can be bent

compliant under pressure during use.

How far into the mat 12 the groove for the fastening arm 30.1 should go from the cold side 16 will depend on the considerations stated above, as well as on the flexibility of the yoke-like bodies 24.1 and their design. In the one in fig. 1 in the embodiment shown in the drawings, the attachment arm 30.1 can lie between approximately 12 mm and approximately 25 mm within the cold side 16.

The fastening means 14.1 further comprise a fastening device 34 which is used to fasten the arm 30.1 to the surface 36 of a furnace wall or furnace lining 38, as shown in fig. 2.

The fastening device 34 has the form of a fastening bracket with a bottom wall 40, a flange 42 on one side of the bottom wall, and

.a gripping flange 44 on the opposite side of the bottom wall 40 is

in engagement with the attachment arm 30.1. The gripping flange 44 can be in gripping engagement with the arm 30.1 and can be crimped, welded or otherwise connected to it.

The bottom wall 40 is designed with a bore 46 which is intended to receive a welding bolt or pin for attaching the fastening device 34 to the surface 36.

As can be seen in particular in fig. 2 in the drawings, the module 10.1 comprises a fastening element 48 which is connected to the fastening device 34 and serves to fasten this to the surface 36>

The fastening element 48 comprises a welding bolt 50 with a threaded stem 52 which passes through the bore 46, and it has at the end a bolt tip 54 with a relatively smaller cross-section.

Pressing means in the form of a nut 56 are arranged on the threaded stem 52.

The fastening device 34 further comprises an arc shield 58 made of ceramic material which is placed on the fastening device 34. The arc shield 58 is held in place by means of an annular retaining disc (not shown) which has radially protruding fingers for engagement with grooves (not shown) in the bolt tip 54.

When mounting the module 10.1 on the surface 36, the module in use will be equipped with fastening means 14.1, the fastening device 34 being mounted on the fastening arm 30.1, and the bolt stem 52 and the nut 56 being arranged in place on the fastening device 34. The module 10.1 also includes a removable guide housing 60 which is placed over the nut 56 and engages with it. The sleeve 60 serves as a guide, which guides during the welding operation and which is used for nut pulling.

When mounting the module 10.1 on the surface 36, an internal welding tool 62 can be used. The tool is an electric tool 62 and has a barrel that is designed to match the sleeve 60, so that a firm contact is made between them.

When the module 10.1 is to be attached to the surface 36, it will be placed against the surface at the desired location, after which the barrel of the tool is inserted into the guide sleeve 60 in good engagement with this.

The tool 62 can be activated in this position, so that an electric current passes through the sleeve 60, the bolt stem 52, the bolt tip 54 and into the cladding 38. Due to the relatively small cross-section of the bolt tip 54, this will burn away, and thereby the arc starts. The arc will be protected by the arc screen 58.

The bolt stem 52 will not initially be moved towards the surface 36 because it is held in place by the holding flange (not shown), as indicated above.

As the welding operation progresses, the intense heat in the arc will burn away the radial fingers on the holding flange, and thereby the bolt stem can be plunged into the molten metal formed by the arc. At this point, the weld is complete and the bolt shank is firmly mounted on the surface 36.

The nut 56 can now be tightened on the bolt shank 52 by simply turning the tool 62 about the axis of the tool barrel, because this engages with the sleeve 60, which in turn engages with the nut 56. The nut 56 can be tightened on the bolt shank 52 until it comes to abut against the fastening device 34 and displaces this towards or in contact with the surface 36. During this displacement, the nut 56 acts as a pressure device which presses the fastening arm 30.1 yieldingly out of the mat 12 towards the surface 36. This unpressed position of the fastening arm 30.1 is shown with dotted lines on fig. 2, while it is shown in solid lines in the yielding depressed position.

During the yielding displacement of the arm 30.1, the yoke-like bodies 24.1 will exert a pull on the anchoring tube 26. As the anchoring tube 26 is an elongated rigid tube, the exerted pull will be distributed over the length of the tube 26. The tube 26 will therefore exert a yielding compression of the fibers between it and the surface 36, so that the fibers and thereby also the mat are pressed in an adaptive fit against the surface 36.

Due to the yielding displacement of the arm 30.1, the yielding compression of the mat 12 to adapted contact against the surface 36 will also be maintained over the entire period of use of the module 10.1.

Because the attachment arm is arranged close to the cold side 16 of the module 10.1, the insulating material in the mat 12 keeps the arm 30.1 and the adjacent part of the arm 28.1 of the yoke-like members 24.1 at such a low temperature that compliance is maintained during use.

This yielding pressing of the mat 12 in an adaptive fit against the surface 36 has the advantage that the tendency for air gaps to form at the separation surface between the cold side 16 and the surface 36 will be reduced or totally eliminated. Because the compliant pressing action is maintained in the yoke-like members 34.1, the cold side 16 will remain, or will substantially remain in compliant contact with the surface 36, even if the surface 36 is curved or bent as a result of temperature variations.

It is therefore believed that elimination or a reduction of the air gap between the cold side 16 and the face 36 will reduce or completely eliminate any air flow downward along the face 36 through this gap during use. It is therefore assumed that this will eliminate or substantially reduce heat loss and thereby also efficiency loss due to such a gas flow.

By reducing the movement of air along the interface between the cold side 16 and the surface 36, it is further believed that corrosion will be avoided.

The module 10.1 also has the advantage that the fastening elements 14.1 mainly remain inside the module, where only the fastening arm 30.1 and the fastening device 34 remain in the area of the cold side 16. These will therefore be the only components that will be exposed to corrosion under average oven conditions . The remaining part of the yoke-like bodies 24.1 will lie at such a great distance from the cold side 16 that they will have such a high temperature that water will not be able to form and that sulfuric acid or sulfuric acid cannot be formed there.

If corrosion were to occur in this low-temperature zone by the formation of iron sulphates at the metal in the cladding 38 and in the yoke-like bodies 24.1, this would give rise to a tendency for corrosion at the cold side 16 of the mat 12. However, such corrosion would have no significant persistent damage to the operation or efficiency of the module 10.1. The corroded ceramic fibers will remain in place and will provide essentially the same insulating effect as the uncorroded fibers. This is in direct contrast to the previously known modules that use cements or adhesives in this separation surface zone. In these previously known modules, the corrosion of the fibers in this zone will cause the fibers to be separated from the adhesive and will thereby cause the insulation to loosen.

In contrast to the previously known modules, corrosion of the module 10.1 at the interface at the cold side 16 will not have any significant effect on the insulation properties of the module 10.1 or on the attachment of the module 10.1 to the surface 36.

This is mainly due to the fact that the anchoring pipe 26 does not corrode and that the yoke-like bodies 24.1 are made of a corrosion-resistant material. With regard to this, it should be pointed out that the yoke-like bodies 24.1 can additionally and if necessary be coated with a corrosion-resistant material.

The module 10.1 has the further advantage that it has four soft side surfaces that do not come into conflict with base plates, blocks or the like.

Corresponding modules 10.1 can therefore be attached to the surface 36, where the side surfaces of these are compressed compliantly into contact with each other. This entails the advantage that if the cladding 38 is deflected or curved towards the interior of the oven into a convex shape as a result of temperature variations, any gaps formed between the adjacent modules 10.1 will tend to be quite narrow and quite shallow.

The module 10.1 also has the advantage that if it is used as a lining in a roof of a furnace or the like, the anchoring pipe 26 will distribute the point tension over the entire module 10.1 and thereby reduce the tendency for the module to sag down from the roof surface under the influence of gravity. This will in turn reduce the tendency for significant gaps to form between the different modules.

It should be pointed out that in fig. 1 in the drawings, the anchoring pipe 26 extends across the fiber planes 20, and thereby the pipe 26 has an effective location in the mat 12. It should also be pointed out that the yoke-like bodies lie mainly parallel to the fiber planes 20.

The fastening members 14.1 can therefore be brought into place by threading approximately half of the fiber strips in the module 10.1 onto the tube 26 and placing the yoke-like members there, the anchoring tube 26 being inserted into the fibers through the hook part 32 and the remaining half of the fiber strips then being threaded on the anchoring pipe 26. It should be pointed out that holes can be designed or drilled through the fiber strips 20 in the mat 12 for receiving the pipe 26.

Reference should now be made to fig. 3 in the drawings, where the reference number 10.3 generally refers to an alternative embodiment of the module according to the invention. However, module 10.3 mainly corresponds to module 10.1. Equal parts are therefore denoted by the same reference number.

The module 10.1 is available in a form that can be described as a half-module. It is therefore rectangular in plan and is relatively narrow. It is primarily adapted for use in places that are too narrow to accommodate regular modules. As the module 10.1 is relatively narrow, only one anchoring tube with only one connecting arm 30.1 can be used in the yoke-like bodies 24.1.

The one in fig. 3 shown module 10.3 is a module that has one more . regular size and which in plan can be square or rectangular. As the module 10.3 is preferably wider than the module 10.1, the fastening means have been pulled out to provide a better distribution of the compliant pull applied to the mat 12 in the module 10.3 throughout the entire module.

The module 10.3 will usually have a size of approximately 30 cm by 30 cm. In a preferred application of such a module, it will be mounted in a room of a size of approximately 27.5 cm by 27.5 cm, and thereby a particularly effective yielding compression of the module is obtained.

The fastening means 14.3 comprise two ceramic anchoring tubes 26 which are arranged parallel and at a transverse distance from each other. The tubes 26 also extend across the fiber planes 20, so that they are effectively and firmly embedded in the mat 12.

Each of the tubes 26 has a length of about 27.5 cm or 30 cm and a diameter of about 12 mm. Each tube will therefore cover an area of almost 36 cm 2 in the direction towards the cold side 16 of the mat 12. The mat itself covers an area of approximately 900 cm 2 in the direction towards the cold side 16 of the mat 12. It has been found that for a module where the material in the mat is a ceramic fiber material, it is sufficient that this ratio between the covering area of the anchoring tubes 26 and the covering area of the mat itself 12 in the direction towards the cold side 16, is approximately 10% of the mat material. With this ratio between the covering areas, it has been found that the pipes during use will not extend the holes in the mat through which the pipes 26 pass. In other words, the surface contact between the pipes 26 and the material in the mat 12 is so large that when the module 10.3 is mounted on a furnace surface using the fastening means in the form of the fastening device 34, the module 10.3 will be held firmly against the surface without the mat 12 being displaced away from the surface due to of the tubes 26 being displaced through the material in the mat in relation to the cold side 16.

By using anchoring elements in the form of anchoring pipes 26, the surface area of the pipes will be increased without increasing the weight of the anchoring elements. This thus gives the advantage that the anchoring tubes 26 will remain embedded in the mat 12 so that the module 10.3 will be effective during use.

The yoke-like members 24.3 comprise a pair of connecting arms 28.3. Each connecting arm 28.3 has at the free end a hook formation 32 which is bent around one of the pipes 26.

The opposite ends of the connecting arms 28.3 are connected to each other by means of a fastening arm 30.3. A fastening device 34 is arranged on the fastening arm 30.3.

The fastening arm 30.3 lies in a recess approximately 12 mm inward from the cold side 16, and it is yieldingly bendable or deformable towards the cold side 16 when it is attached to an oven wall surface, thereby providing a yielding pull on the anchoring tubes and thereby pulls the mat 12 in adaptive contact against said surface.

Due to the arrangement of the anchoring tubes 26 and the yoke-like bodies 24.3, the fastening device 34 will be located close to the cold side 16 of the module 10.3 in a central position, being at a distance inward from the four sides of the module 10.3.

When the module 10.3 is therefore attached to a furnace surface using the fastening device 34, the fastening force from the fastening device 34 to this surface will be distributed fairly evenly through the yoke-like bodies 24.3 and the anchoring tubes 26 and through the mat 12. This even distribution of the fastening force will therefore ensure - that the module 10.3 will be held effectively against the surface to be insulated.

Reference should now be made to fig. 4 to 7 in the drawings where the reference number 10.4 generally refers to an insulation module for high temperature furnaces which essentially corresponds to module 10.3. Corresponding parts are therefore denoted by the same reference number.

In fig. 4 in the drawings, the module 10.4 is shown before it is attached to a surface on an oven mantle. It is shown that the fastening device 34 has a guide sleeve 60 which is arranged to guide an internal welding tool 62 in the correct position, as described with reference to fig. 2.

The fasteners 14.4 in the module 10.4 are shown in detail in fig.. 5 and 6 of the drawings. Corresponding parts have been designated with the same reference numbers as those shown in fig. 2. However, the holding flange 64 is shown in place in fig. 6. This retaining flange 64 cooperates along its outer periphery with the arc shield 58 to shield the arc. The retaining flange 64 has radially inwardly projecting fingers which are in frictional engagement with the bolt tip 54. When these fingers melt during the welding operation, they will release the stem 52, so that the remaining part of the tip 54 can be welded to the surface 36.

In fig. 7 in the drawings, it is shown that the module 10.4 is fixed to the surface 36. The fastening device 34 is shifted to rest against the surface 36 by pulling on the pressure means in the form of the nut 56 on the stem 52. This has resulted in a yielding bending of the fastening arm 30.4 from its original position which is shown with full lines in fig. 7 to its final yielding bent position shown in dotted lines in FIG. 7. This yielding bending or deformation of the attachment arm 30.4 causes a yielding tensile stress on the anchoring tube 26. This tension is distributed by the rigid anchoring tubes 26 throughout the entire length of the mat 12, so that the fiber material in the mat 12 is pressed into conforming contact with the surface 36.

With a suitable yielding compression, the fiber material in the mat 12 will be pressed firmly against and will remain firmly against the surface 36, regardless of the shape of the particular surface in use.

Reference will now be made to fig. 8, where the reference number 10.5 generally denotes yet another alternative embodiment of a module in accordance with the invention. Module 10.5 essentially corresponds to module 10.4 with the exception that the anchoring tubes 26 are arranged parallel to each other, but at an acute angle to a pair of opposite sides in the mat 12.

This arrangement of the pipes 26 entails the advantage that two corresponding modules 10.5 can be mounted next to each other in a yielding connection to each other without the anchoring pipes 26 preventing this connection between neighboring modules 10.5. This will be achieved because the inclined pipes 26 will not lie in line.

It must now be referred to.fig. 9, where the reference number 10.6 refers to yet another alternative embodiment of a module in accordance with the invention.

In the module. 10.6, the yoke-like bodies 24.6 comprise two corresponding yoke-like elements which have been resistance welded to each other, so that a bore 46.6 is formed designed to accommodate a bolt tip 54 and a threaded stem 52 on the fastening element 48.

The module 10.6 entails the advantage that the yielding pull exerted by the yoke-like bodies 24.6 will be further distributed through the main plane of the mat 12 by the four connecting arms, so that the yielding pressure on the mat to adapt to a surface on which the mat is to be mounted, for- improve.

It should now be shown to fig. 10 and 11 in the drawings, where the reference number 24.7 generally refers to an alternative embodiment of the yoke-like members to the yoke-like members 24.1 shown in fig. 1.

The yoke-like members 24.7 are formed by bending an elongated high-strength metal rod into an L-shape which forms the

binding arms 28.7 and fastening arms 30.7.

The connecting arms 28.7 have a hook formation that crouches over the anchoring pipe 26, while the fixing arms 30.7 form a bore 46.7 over which a disc can be placed to distribute the load exerted by the fixing bolt, pin or screw, when these are used to press the fixing arm 30.7 into a compliant installation against an oven wall surface or mantle surface.

Reference should now be made to fig. 12 in the drawings, where the reference number 10.8 generally refers to yet another alternative embodiment of a module in accordance with the invention.

The module 10.8 generally corresponds to the module 10.4 with the exception that the module 10.8 has fastening means comprising three anchoring tubes 26, three connecting arms 28.8 and a single fastening arm 30.8 which is connected to the three connecting arms 28.8.

By increasing the number of anchoring tubes 26 and the number of connecting arms 28.8, the yielding tension exerted on the mat 12 can be increased to the desired degree for the different module sizes and the different applications according to the invention.

In fig. 12, the mat 12 of the module 10.8 has been reinforced or reinforced to improve its durability.

The mat is reinforced by embedding, e.g. by injecting a suitable resin into the zones 75 between the anchoring tubes 26 and the cold side 16.

The resin in the zones 75 hardens, so that reinforced zones 75 are formed which can resist the extension of the holes through which the anchor pipes pass. Thus, when the pipes 26 are pressed compliantly against the furnace wall surface, the pipes will effectively press the insulating material into contact with this surface. The reinforced zones 75 therefore contribute to the distribution of the pressure forces from the pipes 26. Any suitable resin or weak cement, such as, for example, colloidal silicon oxide can be used in the zones 75.

It is easy to see that the pressure forces on the tubes 26 can also be distributed using other means, such as e.g. projections protruding from the pipes, if this is necessary.

In order to facilitate the handling of modules according to the invention, a gas material or paper can be wound on them, or strips of paper, elastic material or the like can be glued onto them. The wrapping or gluing material is preferably a material that will break down when starting to release the mats 12, so that the fibers in the mats can expand compliantly.

Reference should now be made to fig. 13 and 14 in the drawings, where the reference number 62.1 generally refers to yet another alternative embodiment of a module in accordance with the invention.

The module 62.1 generally corresponds to the module 10.3 and the module 10.4 in fig. 3 and 4. Unlike the modules 10.3 and 10.4, however, the module 62.1 is not a module designed to be pressed or compressed compliantly against a furnace wall.

The module 62.1 comprises a mat 63.1 which is a deformable mat made of a suitable insulating material. The module 62.1 has a cold side 65.1 and four side edges 66.1.

The module 62.1 includes fastening means for attaching the mat 63.1 to an oven surface to be insulated. The fastening means 67.1 comprise a number of anchoring elements 68.1 which are tubular. This module 62.1 has two anchoring elements 68.1 which lie at a transverse distance from each other and which lie at a distance from both the cold side 64.1 and the hot side 65.1. Between the cold side and each anchoring element 68.1, there is thus enough insulating material in the mat 63.1 that the anchoring element 68.1 will hold the mat 63.1 in place when it is fixed on an oven surface. Each anchoring element 68.1 additionally has enough insulating material in the direction towards the hot side 65.1 so that the anchoring element 68.1 is protected against the heat from the oven during operation of the latter. The fastening means 67.1 further comprise yoke-like means 69.1.

The yoke-like members comprise a fastening arm 70.1 which lies close to the cold side 64.1 and extends essentially parallel to it. The yoke-like bodies 69.1 further comprise a pair of connecting arms 71.1. The connecting arms 71.1 form a continuation of the material in the fastening arm 70.1 and are thus one with it.

The free end of each connecting arm 71.1 is bent into a circular shape or hook shape which is slidably inserted onto the anchoring tubes 68.1.

The fastening arm 70.1 has a fastening zone 73.1 at its centre. This fastening zone 73.1 is placed close to the cold side 64.1, and it is positioned so that it lies at a distance inwards from the sides 66.1 of the module 62.1. In fig. 13 in the drawings, the attachment zone 73.1 is in reality located centrally between the sides 66.1 of the module 62.1.

When therefore the fastening zone 73.1 is fixed by means of a suitable fastening device to an oven surface, the fastening force in the fastening zone will be distributed via the yoke-like bodies 69.1 and via the anchoring elements 68.1 over the entire effective area of mat no. 63.1. This will therefore ensure that the module 62.1 can easily be fixed effectively in place against a furnace wall by means of a single fastening zone 73.1.

By using a fastening device which is placed on or connected to the fastening zone 73.1, access can be obtained through the center of the mat 63.1 to this fastening device when mounting the mat 63.1 on an oven surface. Subsequently, the material in the mat 63.1 will not only protect the fastening means 67.1, but also the fastening zone 73.1 and the fastening device used together with this, as described above.

This entails a significant advantage according to the invention

in that only a single attachment zone is used which is centrally located in the module, as the attachment force can then be distributed evenly through the deformable insulation material in the mat 63.1.

There is a further advantage with this and in fig. 13

showed embodiment of the invention, namely that the fastening means 67.1

will be very well protected by the mat 63.1 against the heat in the oven^ as the most vulnerable and exposed part of this, namely the fastening zone 73.1 and the fastening arm 70.1, is effectively protected.

By varying the distance that the attachment arm 70.1 protrudes beyond the cold side in the mat 63.1, the distance between the cold side and the oven surface to be protected can vary as desired.

The fastening means 67.1 have the advantage that when they are placed close to the direct heat from the oven during its operation, namely in the zone at the hook forms 72.1, the least stress will be exerted directly on the fastening means 67.1. In the zone where greater stresses are exerted on the fasteners 67.1,

namely at the connection with the connection zones 71.1 and the attachment arm 70.1, the distance from the hot side is the greatest possible, and thereby the lowest possible temperature is kept in this area.

The greatest stress in the fastening means 67.1 therefore occurs in

the area where the fasteners are coldest and are therefore least exposed to a reduction in deformability.

In fig. 13 and 14 in the drawings, the fastening zone 73.1 is formed by a fastening plate 74.1 which is spot welded to the fastening arm 70.1. The fixing plate 74.1 has a bore 76.1 designed to accommodate a bolt, welding bolt or the like for fixing the fixing plate 74.1 to an oven surface, as described above.

Reference should now be made to fig. 15 and 16 in the drawings, where the reference number 67.2 generally refers to an alternative design of the fastening means for use in the module 62.1 in fig. 13.

The fastening members 67.2 correspond in the main to the fastening members 67.1, except as far as the fastening zone 73.2 is concerned.

The attachment zone 73.2 has an average shape of a channel-shaped bracket 74.2 which is arranged on the attachment arm 70.2 by spot welding. The fastening arm 70.2 is in plan view a flattened V-shaped part, so that the bore 76.2 in the bracket 74.2 lies in line with the hook formation 72.2. This can help to provide a more even distribution of the fastening force with which the fastening zone 73.2 is attached to the oven wall.

Reference should now be made to fig. 17 and 18 in the drawings, where the reference number 67.3 comprises fastening means which essentially correspond to the fastening means 67.2 in fig. 15 and 16. The fastening members 67.3 have, instead of a predominantly V-shaped fastening arm 70.2, a fastening arm 70.3 with a semi-circular curved central part, on which the fastening zone 70.3 is arranged. The semi-circular curved part again means that the bore 76.3 in the attachment zone 73.3 can be designed in line with the hook formations 12. i.

Reference should now be made to fig. 19 and 20 in the drawings, where the reference number 67.4 generally refers to yet another alternative embodiment of fastening means in accordance with the invention.

The fastening members 67.4 have a fastening arm 70.4 which is formed by a pair of rods. The rods are arranged parallel and at a distance from each other which is determined by U-shaped connecting arms 71.4 which are resistance welded to the rods in the attachment arm 70.4. The U-shaped connecting arms thus form the hook formations 72.4 at opposite ends of the rods.

The elements that form the fastening arm 70.4 are bent in the central zone in such a way that they form a fastening zone 73.4 designed to accommodate the fastening device or the fastening element.

Reference should now be made to fig. 21 in the drawings, where the reference number 67.5 shows yet another alternative embodiment of the fastening means in accordance with the invention.

The fastening means 67.5 correspond mainly to the fastening means 67.1 in fig. 13. The fastening members 67.5 therefore comprise yoke-like members 69.5 with a fastening arm 70.5, connecting arms 71.5 which extend from and in one with the fastening arm 70.5, as well as a fastening zone 73.5.

At the connection point for each connecting member 71.5 at the end of the attachment arm 70.5, the yoke-like members 69.5, which are made from a stainless steel rod, have been flattened to reduce the bending resistance. It therefore becomes easier to bend the connecting arm 71.5 towards and away from each other in a common plane.

This special design of the yoke-like members 69.5 is particularly suitable for the embodiments according to the invention where the mat in which the yoke-like members are arranged is adapted to be compressed and pressed yieldingly against a furnace surface to be insulated. The yoke-like bodies will therefore usually be located in a recess located within the cold side of the mat. When the attachment zone is then attached to an oven surface, it will be displaced towards or in contact with the oven surface, so that there is a yielding bending of the attachment arm 70.5 and thus a yielding compression of the material in the mat. During this displacement of the attachment arm 70.5, the hook formation 72.5 can be displaced towards each other, unless a certain degree of bending can occur at the connection points between the connection arms 71.5 and the attachment arm 70.5. This may have an undesirable effect on the mat, as there may be a tendency for the effective width of the mat to be marginally reduced. As the flattened zones can be easily bent, such movement of the hook formations 72.5 will be reduced.

Reference should now be made to fig. 22 in the drawings, where the reference number 69.6 generally refers to an alternative embodiment of yoke-like bodies in accordance with the invention. The yoke-like bodies 69.6 serve the same purpose as the yoke-like bodies 69.5. The connecting arms 71.6 in the yoke-like bodies 69.6 are hinged to the attachment arm by means of complementary engaging hook formations 77.6.

Reference should now be made to fig. 23 in the drawings, where the reference number 62.7 shows yet another alternative embodiment of a module in accordance with the invention. This module 62.7 comprises a mat 63.7 and fastening elements consisting of yoke-like elements 69.7, anchoring elements 68.7 and a fastening zone 73.7. The fastening zone 73.7 is located in a recess within the cold side of the mat 63.7, so that when it is pressed into yielding contact with a furnace surface to be insulated, the fastening force will be distributed throughout the mat 63.7 and so that the material in the mat 63.7 is compressed yieldingly to firm plant against the oven surface.

The mat 63.7 is a composite mat that has a first layer 78.7 and a second layer 79.7. The first layer 78.7 will usually be a better insulating material than in the second layer 79.7, and the composite mat will be used to reduce the costs of the insulating material, where this may be possible in a special furnace environment.

When producing a composite mat 63.7, the first layer 78.7 can preferably be produced from ceramic fiber material with a fiber orientation perpendicular to the cold side. The second layer 79.7 can have the same fiber orientation or can be in the form of a carpet where the fiber planes lie mainly parallel to the cold side.

When another layer 79.7 with mat form is used, this will be able to provide effective compliance between the anchoring pipe 68.7 and the cold side, so that a firm connection is thereby obtained between the composite mat 63.7 and the furnace surface during operation. Due to the edge orientation of the fibers in the first layer 78.7, the module 62.7 will also not lose any of the fitting effect in relation to neighboring modules during use.

The composite mat 63.7 may have a first layer 78.7 of SAUDER ceramic fibers with a density of about 128 kg/m-^, while the second layer 79.7 may be a rock wool mat with a density of about 128 kg/m^. With this design and with a composite mat with a thickness of 125 mm, the module 62.7 will be suitable for use in an on oven where the temperature on the hot side will be approximately 771°C. The temperature at the interface between the first layer 78.7 and the second layer 79.7 will be approximately 510°C, while the temperature at the cold side will be approximately 81°C.

The composite mat according to the invention can lead to significant savings in costs when a cheaper insulation material can be used towards the cold side. It therefore seems that this mat type finds special use where, in special cases, lower temperatures are required on the cold side than is usual in this industry.

Reference should now be made to fig. 24 to 26 in the drawings, where the reference number 62.8 refers to yet another alternative embodiment of a module in accordance with the invention. This module consists of a composite mat 63.8 and fasteners 67.8 which are arranged inside the composite mat.

The composite mat 63.8 consists of a first layer 78.8. and another team 79.8. In this embodiment, the first layer is preferably a ceramic fiber mat with a density of approximately 96 kg/m^ and which is available under the trade name SAFFIL, while the second layer 79.8 is preferably a ceramic fiber mat with a density of 128 kg/m"^ which is available under the trade name SAUDER.

The first team 78.8. preferably has a thickness of

114 mm, while the second layer 79.8 has a thickness of approximately 152 mm. With this arrangement, the module 62.8 will be suitable for use in an oven which may have a temperature on the hot side of

1316°C. This will give a temperature of about 1093°C at the anchor tubes 68.8, a temperature of about 945°C at the interface between the first layer 78.8 and the second layer 79.8, and a temperature of about 93°C at the cold side.

Due to relatively high temperatures in the area of the anchoring tubes 68.8, both the anchoring tubes 68.8 and the fastening members 67.8 are made of a ceramic material with a high aluminum oxide content.

The fastening means 67.8 comprise an elongated bolt which extends from the fastening arm 70.8 to the fastening zone 73.8.

In the embodiment shown, the attachment zone is arranged on the cold side, so that when the module 62.8 is attached to an oven surface, the mat 63.8 will not be subjected to yielding compression. If there is a need for yielding compression, the attachment zone can be arranged in a recess within the cold side. It will then also include a laterally protruding fixing bracket which is yieldingly bendable, so that the fastening members 67.8 have a yielding bendable area which is furthest away from the cold side, and is therefore least exposed to loss of bendability under higher temperature conditions during operation.

Reference should now be made to fig. 27 in the drawings, where the reference number 62.9 refers to yet another alternative embodiment of a module in accordance with the invention. The module 62.9 essentially corresponds to the one in fig. 3 showed module 10.3.

The module 69.9 comprises two pairs of anchoring pipes 68.9 and 80.9. The anchoring tubes 68.9 are connected to yoke-like bodies 67.9, while the anchoring tubes 80.9 are connected to corresponding yoke-like bodies 67.9. Each of the yoke-like bodies 67.9 has a fastening zone 73.9 which is generally centrally located in the mat 63.9.

In that in the embodiment in fig. 27 includes a number of sets of anchoring tubes and a number of anchoring means, the module 62.9 can be anchored more firmly to an oven surface, and the anchoring force will be more evenly distributed throughout the mat 63.9. This special arrangement will therefore find application where a more secure attachment and a more secure undersize of the mat is necessary 6 3.9.

The module according to the invention shown in the drawings has the advantage that the module can be built up in a simple and efficient manner from separately manufactured components that are easy to assemble. When the components are assembled, they form a module which has support means and fixing means which are complete inside the mat to fix the module to a surface. The module can be mounted by providing access to the attachment zone in the attachment devices through the material in the mat.

The module entails the further advantage that the position of the fastening means can be varied to provide the desired distribution of the fastening force through the mat in the module. The location of the fastening elements can also be varied to be able to carry out a simple assembly on an oven surface or to be able to carry out a yielding compression against an oven surface. The fastening means can therefore be positioned such that the fastening zone lies in a recess within the cold side and must therefore be displaced yielding cc compressing the fibers in the module when it is attached to a furnace surface. The degree of compression can be adjusted by adjusting the distance within which the attachment zone lies on the cold side.

By using a pair of anchoring elements at a transverse distance from each other and by using mainly U-shaped or channel-shaped fastening means, the fastening force can be distributed sufficiently evenly throughout the entire mat in the module to either hold it effectively in place, or effectively in yielding against a oven surface during use and during the normal effective lifetime of the module.

The special design of the yoke-like bodies has the advantage that the anchoring elements will be pulled towards the cold side in a plane that lies mainly at right angles to the cold side with a slight tendency for the anchoring tubes to be displaced laterally inside the module. By placing • the fastening elements or a fastening zone centrally in the module, the module can also be mounted securely at a single fastening point which will be shielded from the heat of the oven at all times. This simple attachment point is sufficient to attach an average module and makes the module cheap to manufacture and cheap to install. As the fastening elements or the fastening zone are centrally located, the fastening force can be distributed evenly via the yoke-like elements, via the anchoring element and thereby also via the material in the mat.

Claims (31)

1. Insulation element (10.1) for insulating oven walls (36), which element comprises: a) an insulation mat (12) of elastically yielding insulation material with a cold side (16) to be placed against the oven wall (36), and an opposite hot side (18) , and b) fastening means (14,1) for fixing the mat (12) to such an oven wall (36), c) and in that the fastening means (14,1) comprise anchoring means (22) which are arranged in the mat ( 12) at a distance both from the cold side (16) and from the hot side (18) for setting the fastening means (14,1) in relation to the mat (12), as well as connecting means for fixing on a furnace surface for fixing the insulation element on the furnace surface , characterized in that i) the connecting members (24,1) are connected to the anchoring members (22) so that they are displaceable in relation to these, ii) in that the connecting members (24,1) are recessed inward in relation to the cold side (16 ) for the fasteners (14.1) for compressing the cold side (16) of the mat (12 ) against such a furnace wall (36) when force is applied to the connecting means (24,1) to press them against such a furnace wall (36) for attachment thereto, and iii) that the anchoring means (22) comprise at least one anchoring tube (26) which is positioned to extend through the mat (12) for distribution of force applied to the connecting means (24,1) through the mat (12) for compressing the cold side (16) of the mat into firm contact with the furnace wall (36) below use. 2. Insulation element as specified in claim 1, characterized in that the anchoring device (22) comprises several elongated anchoring parts (26). 3. Insulation element as specified in claim 1 or 2, characterized in that the insulation material is a fibrous material which comprises fiber planes (20) which are arranged to run perpendicular to the insulation element tet's (10.1) warm side (18) so that the direction of the fiber material's fibers in the fiber plane (20) is random. 4. Insulation element as stated in claim 1 or 2, characterized in that the fastening means (14.1) are elastically deformable to tension the mat (12) or to force it into contact with the surface (36) to be insulated when the fastening means (14.1) is attached to the surface (36). 5. Insulation element as specified in claim 2, characterized in that the support members (24.1) have at least one connection arm (28.1) which is connected to the anchoring device (22) and runs in the direction towards the cold side (16), and which has a fastening arm (30.1) for attachment to the surface (36) to be insulated. 6. Insulation element as specified in claim 5, characterized in that the carrier (24.1) is elastically deformable by means of an attachment arm (30.1), part of which is elastically flexible and can be elastically bent in the direction of the surface (36) to be isolated in order to be attached to the surface (36) and thereby elastically bend the mat (12) towards the surface (36). 7. Insulation element as stated in claim 6, characterized in that the attachment arm (30.1) extends transversely in relation to the connection arm (28.1), and in that the attachment arm (30.1) is arranged close to the cold side (16) so that the material of the mat (12) must protect the elastically flexible part from losing its elasticity when it is used in the temperature conditions for which the insulation (10.1) is designed. 8. Insulation element as stated in claim 5, characterized in that the carrier (24,1) has two connecting arms (28,3) which are connected by means of a fastening arm (30,3) to provide a channel form for the carrier (24,4 ), and that the free end part of each connecting arm (28,3) is connected to one of the anchoring parts (26). 9. Insulation element as stated in claim 8, characterized in that the anchoring device (22) comprises a number of elongated anchoring tubes (26) which are arranged in the mat (12) separated from each other in the lateral direction, and that a connecting arm (28.3) is connected to each pipe. 10. Insulation element as stated in claim 2, characterized in that the connection arm (28,1) comprises a fastening device (34) which is to be attached to the surface (36) to be insulated, for fastening the connection arm (28,1) to the surface (36), which fastening device (34) delimits a fastening zone (73.1) which lies mainly in the center in relation to the periphery of the cold side (16). 11. Insulation element as specified in claim 10, characterized in that the connection arm (28,1) has a carrier (24,4) with two connection arms (28,3) connected together by means of attachment arms (30,3) so that the carrier (24, 4) mainly shows the shape of a channel part, where the free ends of the connecting arms (28,3) are connected to the anchoring parts (26), and the fastening device (34) is attached to the fastening arms (30,3). 12. Insulation element as specified in claim 11, characterized in that the fastening device (34) has a fastening element (48) which consists of a welding bolt (50) which is attached to the surface (36) by means of internal welding and has a threaded stem (52) and a bending member formed by a nut (56), which bending member bends the fastening member (14.1) in the direction towards the surface (36). 13. Insulation element as specified in claim 12, characterized in that the fastening device (34) is provided with a fastening support connected to the connecting arm (28.1) which exhibits a bore (76.1) through which the easily fusible part (54) of the welding bolt (50) extends, as a arc screen (58) arranged in the fixing support surrounds the easily fusible part (54). 14. Insulation element as stated in claim 11, characterized in that it exhibits a fastening element (48) located in the fastening device (34) which is attached to the surface (36) to be insulated and which is provided with a bending member (56) to force the fastening element ( 48) and thus also the fastening member (14.1) against the surface (36) so that the mat (12) is forced or pressed into firm engagement with the surface (36). 15. Insulation element as stated in one of the claims 1-4, characterized in that the fastening device (14,1) is inserted into the mat (12) and the anchoring device (22) extends transversely in relation to the fiber planes (20). 16. Insulation element as stated in claim 8, characterized in that the carrier (69.5) is leveled on the attachment zone between each connection arm (71.5) and attachment arm (70.5) in order to reduce the bending resistance in the area, so that the connection arms (71.5) are bendable towards each other and also from each other. 17. Insulation element as specified in claim 2, characterized in that the elongated anchoring parts (26) extend through the mat (12) and distribute the force directed at the connecting arm (28.1) through the mat (12) so that the cold side of the mat (16) is pressed elastically and mainly completely adaptable to engagement with the oven surface (36) during the fastening. 18. Insulation element as specified in claim 8, characterized in that the connection arms (28.3) form an uninterrupted extension of the material of the attachment arms (30.3) at the opposite ends of the attachment arms. 19. Insulation element as stated in one of claims 1-18, characterized in that the anchoring device (22) comprises two elongated, tubular anchoring parts (26) whose projecting outer surface in the direction of the cold surface (16) comprises approx. 10 percent of the module's projected outer area. 20. Insulation element as stated in one of the claims 1-19, characterized in that the mat (12) is a combination mat (63.8) which exhibits several layers consisting of different insulating materials. 21. Insulation element as stated in claim 1 or 2, characterized in that the connection arm (28.1) has an attachment zone (73.1) which is used when the connection arm (28.1) is attached to the oven surface (36) to be insulated, the attachment zone (73.1) being removed in relation to the cold side (16) of the mat (12), but it is however closer to the cold side (16) than the anchoring device (22). 22. Insulation element for insulating an oven surface (36), which insulation (10,1) comprises a cold side (16) to be placed against the oven surface (36) during use, an opposite hot side (18) and several sides, and which insulation (10,1) comprises a deformable mat (12) of a fibrous insulation material and a fastening means (14,1) by means of which the mat (12) is attached to the surface (36) whereby the fibrous insulation material exhibits fiber planes (20) that extend transversely to the plane of the hot side (18), the fibers of the fibrous material running in random directions within the fiber planes (20); and the fastening means (14,1) comprises a number of elongated anchoring parts (26) which lie in the mat (12) transversely in relation to the fiber planes (20) at a distance from both the cold (16) and the hot (18) side, characterized by that the fastening element further comprises a carrier (24,1) which exhibits a fastening arm (30,3) and a number of connecting arms (28,3) which extend from the fastening arm (30,3), whereby the free end of each connecting arm (28,3) is connected to one of the anchoring parts (26) and that the fastening arms (30,3) delimit a fastening zone (73,1) which is located close to the cold side (16) and internally separated from the sides of the insulating element (10,1) and which is used for fastening the insulation element (10,1) to the oven surface (36). 23. Insulation element as specified in claim 21, characterized in that it comprises a fastening device (34) which is connected to a fastening arm (30.3) and which delimits a fastening zone (73.1). 24. Insulation element as specified in claim 22, characterized in that it comprises a fastening element (48) which is placed in the fastening device (34) and which is attached to the surface (36) so that the fastening device (34) and thus also the insulation element (10.1) is attached to the oven surface (36). 25. Insulation element as specified in claim 23, characterized in that the fastening element (48") comprises a welding bolt (50) which is attached to the surface (36) by internal welding, and which welding bolt comprises a threaded stem (52) and a nut (56) by means of which the fastening member (14.1) is bent towards the surface (36). 26. Insulation element as specified in claim 21 or 24, characterized in that the fastening device (34) comprises a fastening support connected to the connection arm (28.1) which exhibits a bore (76.1) through which the weld bolt's fusible part (54) extends, the fastening support being provided with an arc shield surrounding the fusible portion (54). 27. Insulation element as stated in claim 25, characterized in that the connection arms (28,3) form an uninterrupted extension of the attachment arm (30.3) material at the opposite ends of the attachment arm (30.3). 28. Insulation element as stated in claim 25, characterized in that the anchoring device (22) comprises two elongated, tubular anchoring parts (26) whose projected outer surface in the direction towards the cold side (16) is approx. 10% of the module's projected surface area. 29. Method for insulating an oven surface (36), which method comprises attaching an insulation mat (12) of an elastic, deformable insulating material to the oven surface (36), which mat (12) has a cold side (16) to be placed against the oven surface (36) and an opposite hot side (18), where the fastening is carried out by means of a fastening element (14.1) which is separated from both the cold side (16) and the hot side (18), characterized in that the fastening element (14.1) is subjected to a force to displace it towards the oven surface (36) and to force the cold side (16) of the mat (12) into engagement with the furnace surface (36), the attachment means (14.1) including an anchoring device (22) extending through the mat (12) to distribute the directed force through the mat to press the cold side of the mat (16) elastically against the oven surface (36). 30. Method as stated in claim 28, characterized in that the cold side (16) of the mat (12) is tensioned in suitable engagement with the oven surface (36). 31. Method as stated in claim 28 or 29, characterized in that the fastening means (14.1) is displaced elastically towards the oven surface (36) to tension the cold side (16) of the mat into elastic engagement with the oven surface (36) to remove the slits between the cold side (16) and the oven surface (36).