NL2013697B1

NL2013697B1 - Burner cover insulation device for a boiler and method for manufacturing such a device.

Info

Publication number: NL2013697B1
Application number: NL2013697A
Authority: NL
Inventors: Den Hartogh Ike; Tournier Remco; Tournier Eric
Original assignee: Ind Ceram Linings B V
Priority date: 2014-10-28
Filing date: 2014-10-28
Publication date: 2016-09-05
Also published as: NL2015669A; NL2013697A; NL2015669B1

Abstract

The invention relates to a burner cover insulation device for shielding a burner cover from a boiler burner, comprising a cover layer comprising a heat resistant inorganic fibrous material and having an outer peripheral edge, a support layer having an outer peripheral edge that at least extends to the outer peripheral edge of the cover layer, and a filling material forming a layer between the cover layer and the support layer, wherein a through hole extends through the cover layer and the support layer, the through hole being delimited by inner peripheral edges of the cover layer and the support layer, the cover layer and the support layer being connected along their inner peripheral edges and along the outer peripheral edge of the cover layer.

Description

BURNER COVER INSULATION DEVICE FOR A BOILER AND METHOD FOR MANUFACTURING SUCH A DEVICE BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a burner cover insulation device for protecting a burner cover in a boiler, in particularly suitable for damp environments with high temperatures, and a method for manufacturing such a device.

Description of the Related Art

In a conventional boiler, fuel, such as gas or oil, is burned and the hot gasses produced are passed through a heat exchanger, usually in a housing, where much of the heat of the hot gasses is transferred to a heat transfer medium such as water, thus raising the medium's temperature.

One of the hot gasses produced in the combustion process is water vapour (steam), which arises from burning the hydrogen content of the fuel. A condensing boiler extracts additional heat from these waste gasses by condensing the water vapour to liquid water, thus recovering its latent heat of vaporization. A typical increase of efficiency can be as much as 10-12% compared to a non-condensing boiler, so the choice of materials used in the areas where liquid is present have to be suitable. At high temperature most commonly used are aluminium alloys and stainless steel.

Condensing boilers are provided with a heat exchanger and a burner to heat the water or other heat transfer medium in the heat exchanger. The temperatures associated with heating the medium are usually above 500°C or even above 1000°C. To protect the parts of the boiler outside the heat exchanger and to prevent any flue gasses to escape the heat exchanger, the boiler is provided with a sealing gasket to prevent any hot gasses to escape the boiler housing and direct them towards a flue, and an insulating part in the shape of a burner stone to shield the cover plate of the boiler from the high temperatures in an interior of the boiler housing. In addition to the high temperatures, the condensate produced is slightly acidic, 3-5 pH.

The sealing gasket seals the periphery of the cover plate from the heat exchanger housing. The burner stone is usually made of moulded granular vermiculite with a binder or bio soluble inorganic fibres in a binder. A disadvantage of the used sealing gasket and the burner stones is that they have a relatively high failure rate in the harsh environment of the heat exchanger housing. A first disadvantage of the burner stone is that it is fragile to begin with. The burner stone is easily damaged during transport and handling. Secondly, the binder of both burner stones is burnt out of the stones upon first use of the burner stones in the boiler due to the high temperatures, thereby weakening the structure of the burner stones.

In addition, the vermiculite burner stone is not suitable for withstanding thermo shock that is characteristic for modulating condensing boilers. In these condensing boilers, the temperature can shift between relatively low temperatures of below 300°C to relatively high temperatures to 1000°C. The thermo shock results in failure of the vermiculite burner stone, such as cracks, flaking and complete failure of the stone, resulting in reduced protection of the cover plate and potential failure of the sealing gasket.

The inorganic fibre burner stone comprises inorganic high temperature resistant fibres that are bio- or body soluble, i.e. soluble in the human body. Thus they are also soluble in water, which is contained in the condensate produced in the burner. Upon use of the inorganic fibre burner stone, it will come into contact with the condensate and will bit by bit dissolve. The result is failure of the inorganic burner stone, similar to the vermiculite burner stone. In the past, other inorganic fibres than bio- or body soluble inorganic fibres were used, but these inorganic fibres are nowadays used less and less due to potential health risk, i.e. potential carcinogenic properties.

The sealing gasket itself is not capable of withstanding the high temperatures in the heat exchanger and is also protected by the burner stone. During use and particularly upon failure of the burner stone, the quality of the sealing gasket deteriorates quickly, thereby reducing the sealing ability of the sealing gasket.

It would be desirable to provide a burner cover insulation device and a sealing gasket capable of withstanding the harsh environment within the condensing boiler thereby overcoming the disadvantages of the known device.

BRIEF SUMMARY OF THE INVENTION

According to the invention, there is provided a burner cover insulation device for shielding a burner cover from a boiler burner, comprising a cover layer comprising a heat resistant inorganic fibrous material and having an outer peripheral edge, a support layer having an outer peripheral edge that at least extends to the outer peripheral edge of the cover layer, and a filling material forming a layer between the cover layer and the support layer, wherein a through hole extends through the cover layer and the support layer, the through hole being delimited by inner peripheral edges of the cover layer and the support layer, the cover layer and the support layer being connected along at least part of their inner peripheral edges and along at least part of the outer peripheral edge of the cover layer.

The burner cover insulation device comprises a cover layer comprising a heat resistant inorganic fibrous material, which has the function to protect the filling material from the heat produced by a burner in the boiler. Preferably, the heat resistant inorganic fibrous material of the cover layer comprises a textile material of an inorganic fibrous material, such as a woven or non-woven inorganic fibre, preferably a silica fibre. The inorganic fibrous material may be coated with a heat resistant inorganic, preferably a mineral coating, such as a vermiculite coating. A second component is a support layer that gives support to the cover layer and gives strength to the burner cover insulation device. In between the support layer and the cover layer a layer of filling material is provided. The filling material serves as an insulating material and is used to define the thickness and the shape of the burner cover insulation device.

The through hole extends through the cover layer and the support layer, such that in use a burner of a boiler can be put through the through hole. The through hole is delimited by the inner peripheral edges of the cover layer and the support layer, and if applicable, by the inner peripheral edge of the layer of filling material. The filling material does not extend beyond the inner peripheral edges of the cover layer and the support layer.

The cover layer and the support layer are connected along at least part of their respective inner peripheral edges and along at least part of the outer peripheral edge of the cover layer. It may be that along the inner peripheral edges and/or the outer peripheral edge of the cover layer an unconnected portion is provided for further processing of the burner cover insulation device, see below. Preferably, the cover layer and the support layer are connected along the lull inner peripheral edges and/or along the full outer peripheral edge of the cover layer.

In use, the burner cover insulation device thermally insulates a burner house that houses both the burner and a heat exchanger of the boiler, from a burner cover plate and a remainder of the boiler. The burner cover plate is protected from the heat in the housing by the device. Using a heat resistant fibrous inorganic material, such as a high temperature resistant, inorganic (mineral or ceramic) textile, enhances the mechanical strength and integrity of the burner cover insulation device during use. The fibres of the heat resistant material can be bonded together by weaving, braiding, crocheting, knotting or knitting, or by pressing the fibres together to form a felt, i.e. a non-woven textile. As the fibres of the fibrous material are mechanically bonded, a binder may not be necessary to bind them together. However, a binder may be used during manufacturing and processing of the fibrous material. This binder material may be removed from the fibrous material, for example being burnt away upon first use of the burner cover insulation device within the boiler. The integrity of the mechanical bond is thus maintained during use as any binder may be omitted or may be burnt away upon first use. Additionally, thermo shock resistance is increased by the use of a fibrous material. The enhanced mechanical bonding and the increased thermo shock resistance ensure that failure through fracture or flaking is prevented, increasing the life time of the burner cover insulation device and thereby reducing maintenance costs of the boiler. Another advantage of using a mechanically bonded heat resistant fibrous inorganic material is the relatively durability of the device during transport and handling. This durability is especially advantageous upon building in a device according to the invention into an existing boiler. The durability decreases the chance of any debris coming off the device, the debris contaminating the heat exchanger and the burner.

The cover layer functions as a heat resistant shield to shield the heat from the device, for instance by reflecting part of the heat from the boiler burner into a burner housing towards the heat exchanger. Heat that is not reflected by the cover layer is absorbed by the filling material, that functions as a thermal insulator for the burner cover insulation device. The support layer provides strength to the device and supports both the relatively flexible cover layer and filling material.

According to an embodiment, the device comprises a further through hole at a distance different from zero from the through hole. In use, such a further through hole can function as a look-through to the looking glass of the boiler, or to an ignition pen or the like.

According to an embodiment, the cover layer and the support layer are adjacently connected to each other along at least a part of the outer peripheral edge of the cover layer to enclose a receiving space extending along at least part of the inner peripheral edge and being delimited by connections along the inner and outer peripheral edges, wherein at least a part of the receiving space is filled with a filling material comprising an inorganic fibrous material, such that a raised portion with respect to the outer peripheral edge is formed.

The raised portion filled with the filling material increases the thermal insulating properties of the device. Preferably, the raised portion is also formed with respect to the inner peripheral edge. Alternatively, the inner peripheral edge is a part of the raised portion with respect to the outer peripheral edge. The advantage of this alternative is that thermal hot spots around the burner are prevented. For this purpose, the inner peripheral edge may be covered with a heat resistant mantle, preferably comprising a heat resistant inorganic material.

The receiving space is at least partially filled with filling material, preferably the receiving space is substantially fully filled with filling material. The rate of filling of the receiving space depends on the filling material used. Relatively smaller fibres, granules or other particles tend to fill smaller spaces better than relatively large fibres, granules or other particles. The filling material can be used in the form of a loose filling or wool that can be wadded or stuffed in the receiving space, a felt, a paper, a granular material or a combination thereof. Alternatively, the filling material can be a layered material with a certain width and a height that leaves a part of the receiving space unfilled or empty, notably parts close to the inner and outer peripheral edges. In addition, the unfilled spaces of the receiving space may be filled with filling material in another form, such as a loose filling material as described above.

It is preferred that the filling material comprises an inorganic fibrous material, such as an electronic grade glass fibre, also called e-grade glass fibre or e-glass, comprising alumino-borosilicate glass with less than 1% w/w alkali oxides, e.g. comprises at least one of aluminium oxide (AI2O3), silicon oxide (S1O2), calcium oxide (CaO) and magnesium oxide (MgO). Preferably, the inorganic fibrous material is soluble in water or a saline environment, preferably soluble in a human body, or biodegradable.

Preferably, the support layer and the cover layer are connected along the inner peripheral edge and the outer peripheral edge and form a receiving space between them. The receiving space is thus defined by the support layer, the cover layer and the inner and outer peripheral edge, respectively.

According another embodiment, the layer of filling material between the cover layer and the support layer extends from the inner peripheral edge to the outer peripheral edge of the cover layer, thereby forming an inner and an outer peripheral edge of the layer of filling material, such that the cover layer, the layer of filling material and the support layer are connected with each other along the inner peripheral edges and along at least the outer peripheral edges of the cover layer and the filling material.

Preferably, the connection between the cover layer, the layer of filling material and the support layer is such that a raised portion with respect to at least the outer peripheral edge of the cover layer is formed.

According to a preferred embodiment, a sealing element for sealing a burner house of the boiler in use is provided along at least the outer peripheral edge of the support layer. The sealing element may be used to prevent any flue gasses to escape the boiler housing and to direct them towards the heat exchanger and/or a flue.

Providing a sealing element to the outer peripheral edge of the support layer has the advantage of combining the burner cover insulation function of the burner stone from the prior art with the sealing function of the sealing gasket. The sealing element at the outer peripheral edge of the support layer is supported by the support layer as well. Preferably, the sealing element is a coating comprising a silicone rubber. The sealing element can cover both the outer peripheral edges of the support layer, the filling material and/or the cover layer.

According to an embodiment, the outer peripheral edges of at least the support layer and the cover layer coincide, and wherein the cover layer and the support layer are connected along the coinciding outer peripheral edges. The sealing element is then preferably applied to all outer peripheral edges to optimize the sealing ability of the device. In this embodiment, the burner cover insulation device can be combined with a separate sealing element that is not provided at the outer edge of the support layer, such as a sealing gasket, for instance a silicon ring or profile of appropriate size. Using the burner cover insulation device according to the invention with a gasket will also increase the life time of that gasket, as failure of the gasket due to failure of the burner cover insulation device is prevented.

Alternatively, the outer peripheral edge of the support layer extends beyond at least part of the outer peripheral edge of the cover layer, forming an outwardly extending flange. An advantage of this embodiment is that the distance between the conventional burner stone and the sealing gasket is overcome and the sealing element can be provided along the outer peripheral edge of the extended support layer. This provides for a combination of the functions of the conventional burner stones and sealing gaskets in one device. This may be lead to efficiency in installing the device and/or in manufacturing and/or supply.

The device can take on any shape or form, depending on the form or shape of the burner cover plate, the burner and/or the available space within the housing.

In the alternative embodiment, the support layer extends beyond the outer peripheral edge of the cover layer. The outer peripheral edge of the cover layer is then connected to a support surface of the support layer, with or without the layer of filling material in between. For this embodiment, it is preferred that the coating is applied along the outer peripheral edge of the support layer covering the support layer over its full thickness, forming a single unit.

According to a further embodiment, the through hole is aligned with respect to the centre of both the cover layer and the support layer. It is preferred that the inner peripheral edge and the outer peripheral edge are centred with respect to each other such that a distance between the outer and inner peripheral edge is the same along their periphery, i.e. that a width dimension of the cover layer extending from the inner peripheral edge to the outer peripheral edge of the cover layer is equal along the periphery. Preferably, the burner cover insulation device is substantially shaped as an annulus or annular ring having an outer and an inner diameter, wherein the inner diameter is defined by the through hole and the outer diameter is defined by the outer peripheral edge of the support layer. The above mentioned further through holes can be provided within the annular ring. Alternatively, the burner cover insulation device can have a different shape, such as a rectangle, triangle or other polygonal shape. The through hole can be substantially circular shaped, but can also be rectangular, triangular or other polygonal shape, preferably coinciding with the shape of the device. It is preferred that the shape and dimensions of the through hole coincide with the shape and dimensions of the burner of the boiler, such that the burner can be fittingly arranged in the through hole.

According to a further embodiment, the raised portion described above forms at least a part of a raised annulus surrounding the through hole. It is preferred that the raised portion forms a raised annulus surrounding the through hole. Alternatively, the raised portion can form a part of the annulus, for instance due to the further through holes through the cover layer and the support layer to have access to the looking glass in the boiler. Such a further through hole does not need to be centred with respect to the centre of the cover layer and the support layer. The cover layer and the support layer are also connected along the inner peripheral edge of this additional through hole and therefore in addition define a further inner peripheral edge, and, if applicable, delimit the receiving space.

It is furthermore preferred that the cover layer and the support layer are connected through a mechanical connection, such as stitching by sewing or clamping. Due to the high temperatures in the boiler, a mechanical connection between the support structure and the heat resistant cover is preferred. This mechanical connection can be done by clamping, but preferably by stitching. For the stitching, a metallic yam comprising a non-metallic sheath can be used. Preferably, a metallic yam comprising an iron alloy, such as a stainless steel, preferably with a cotton sheath, is used. The non-metallic sheath protects the stitching machines, or sewing machines, from the metallic yarn. The non-metallic sheath can comprise cotton, silk, wool, or a synthetic material like nylon or any other plastic material that is suitable for such application. Using only metallic yam without a non-metallic sheath would lead to increased wear and subsequent failure of the sewing machines. Upon first use of the burner cover insulation device, the non-metallic or cotton sheath is burned away, leaving only the metallic yarn in the burner cover insulation device. The mechanical connection can also be established by connecting a mantle to the inner peripheral edges of the cover layer and support layer, respectively. The mantle can be connected to the cover layer, the relatively hot side of the device during use, with a yam comprising an inconel alloy.

The mantle can be connected to the side of the support layer facing away from the cover layer, i.e. the ‘cold’ side during use of the device, by means of stitching or by means of an adhesive, such as a silicone based putty.

According to a further embodiment, a side of the support layer facing away from the cover layer comprises a protective layer to protect the support layer, such that the support layer is between the protective layer and the cover layer. The support layer is preferably made of a similar material as the filling material, i.e. an inorganic fibrous material in a woven or non-woven form. To shield the material of the support layer from the environment in the burner housing, a protective layer is applied to the side of the support layer facing away from the cover layer. This protective layer can comprise an aluminium foil or coating or a polymer coating, such as a polyurethane coating. Preferably, in the case the support layer extends beyond the outer peripheral edge of the cover layer, the side of the extending part of the support layer, i.e. the outwardly extending flange, facing the cover layer is provided with a similar protective layer, preferably comprising a polyurethane coating.

The support layer can furthermore comprise a fibrous inorganic material, such as an inorganic fibre paper or textile, such as a mineral or glass fibre paper or textile. In this context, paper may mean a felt made from an inorganic fibre wool. The protective layer can furthermore comprise an inorganic textile coated with a polymer coating, for instance a mineral or glass fibre textile coated with polyurethane.

The heat resistant material of the cover layer comprises a heat resistant inorganic textile layer, preferably a woven mineral or glass fibre textile, such as a silica fibre textile, preferably provided with a heat resistant coating on at least a side facing away from the filling material.

The invention is also related to a boiler comprising a burner, a burner house housing the burner and a heat exchanger, a cover plate for covering the burner house, and a burner cover insulation device according to any of the preceding claims for shielding the cover plate from the burner and heat exchanger, wherein the burner extends through the through hole of the burner cover insulation device into the burner housing, wherein the cover layer faces an interior of the burner house and an outer side of the support structure faces the cover plate of the boiler.

According to an embodiment, a sealing element for in use sealing the burner house of the boiler is provided along at least the outer peripheral edge of the support layer. Depending of the embodiment of the device, the sealing element can be provided along any combination of outer peripheral edges, such as along the outer peripheral edge of the support layer alone, along the outer peripheral edge of the cover layer and the support layer, or along the outer peripheral edge of the cover layer, the layer of filling material and the support layer.

According a further embodiment, the outer peripheral edge of the support layer extends beyond at least part of the outer peripheral edge of the cover layer, forming an outwardly extending flange.

The invention furthermore relates to a method for manufacturing a burner cover insulation device as described above, the method comprising: - providing a support layer and a cover layer, both layers having an outer peripheral edge; - providing a filling material between the support layer and the cover layer; - connecting the cover layer along at least part of the outer peripheral edge of the cover layer to the support layer; - cutting a through hole extending through the support layer and the cover layer, thereby forming an inner peripheral edge; and - connecting the cover layer along at least a part of its outer peripheral edge and/or its inner peripheral edge to the support layer..

According an embodiment, a receiving space is formed between the support layer and the cover layer after connecting the cover layer along at least a part of its outer peripheral edge and/or its inner peripheral edge to the support layer, and the filling material is provided within at least part of the receiving space to form a raised portion with respect to the inner peripheral edge.

According to a further embodiment, after connecting the cover layer along at least a part of its outer peripheral edge and/or its inner peripheral edge to the support layer, a filling opening between the support layer and the cover layer is provided on at least one of the outer and inner peripheral edge and the method further comprises filling at least part of the receiving space with the filling material such that the raised portion with respect to the outer peripheral edge of the cover layer is formed, and closing the filling opening after filling the receiving opening by connecting the cover layer and the support layer at the filling opening.

The filling opening can be provided with a valve to allow filling material to enter the receiving space. Preferably, the valve is a one-way valve to prevent the filling material to escape the filling material after filling. The valve can be removed upon closing the filling opening during the manufacturing process.

According to an alternative embodiment, providing a filling material between the support layer and the cover layer comprises providing a layer of filling material between the support layer and the cover layer before the steps of connecting the cover layer along at least a part of its outer peripheral edge and/or its inner peripheral edge to the support layer.

According a further embodiment, the layer of filling material between the cover layer and the support layer extends from the inner peripheral edge to the outer peripheral edge of the cover layer, thereby forming an inner and an outer peripheral edge of the layer of filling material, whereby the step of connecting the cover layer along at least a part of its outer peripheral edge and/or its inner peripheral edge to the support layer comprise connecting the cover layer, the layer of filling material and the support layer with each other along the inner peripheral edges and along at least the outer peripheral edges of the cover layer and the layer of filling material.

According to another embodiment, the method comprises providing at least the outer peripheral edge of the support layer with a sealing element for sealing a burner house of the boiler in use.

Alternatively, the sealing element can be provided separately upon instalment of the device into a boiler.

According to another embodiment, the method comprise before providing a filling material between the support layer and the cover layer, but after connecting the cover layer along at least a part of its outer peripheral edge and/or its inner peripheral edge to the support layer, the step of placing the device into a mould such that upon filling the receiving space with filling material, the raised portion assumes the shape of the mould. In this way, any desired shape of the raised portion can be formed.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the invention will be further appreciated upon reference to the following drawings of a number of exemplary embodiments, in which:

Figure 1 shows a perspective view of a first embodiment of the burner cover insulation device according to the invention.

Figure 2 shows a cross section along II-II in figure 1 of the first embodiment of the burner cover insulation device.

Figure 3 shows an exploded schematic view of an interior of a boiler comprising the burner cover insulation device of fig. 1.

Figure 4 shows a perspective view of a second embodiment of the burner cover insulation device according to the invention.

Figure 5 shows a cross section along V-V in fig. 4 of the second embodiment of the burner cover insulation device.

Figure 6 shows a perspective view of the burner cover insulation device of fig. 4 arranged around a burner of a boiler.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Figure 1 shows in perspective view of a first embodiment of the burner cover insulation device 1 according to the invention. The burner cover insulation device 1 comprises a cover layer 2 and a support layer 7. In between the cover layer 2 and the support layer 7, a layer of filling material 8, shown in figure 2, is provided. A through hole 5 extends through the cover layer 2 and the support layer 7 to accommodate a burner 20, as shown in fig. 6. The through hole 5 is delimited by respective inner peripheral edges 9, 10 of the cover layer 2 and the support layer 7. The cover layer 2 and the support layer 7 are connected along their respective outer peripheral edges 11, 12 and inner peripheral edges 9, 10 by means of stitches 3, 6 respectively. The outer peripheral edges 11, 12 of the cover layer 2 and the support layer 7 coincide in this embodiment of the device 1.

The mechanical connection by means of the stitches 3, 6 secures the cover layer 2 and the support layer 7 even under the harsh environment of a boiler. For the stitches 3, 6 a metal yam, preferably comprising an iron alloy, covered with a non-metallic coating or sheath, preferably a cotton sheath, can be used. The cotton sheath will be burned upon the first use of the burner cover insulation device in a boiler. The iron alloy yarn will remain to connect the cover layer 2 and the support layer 7.

The cover layer 2 and the support layer 7 define a receiving space 13, see fig. 2, in which the filling material 8 is provided. The receiving space 13 with the filling material 8 forms a raised portion 14 with respect to the inner and outer peripheral edges. The through hole 5 is centred with respect to the raised portion, or at least with respect to the outer peripheral edge of the cover layer 2.

In addition to the through hole 5 a number of further through holes 15, 16 are provided that extend through the cover layer 2 and the support layer 7. These further through holes can be used to uncover the looking glass of the boiler to check whether the burner is still working, or can be used to accommodate any fastening means through the device, such as bolts and/or screws.

The further through holes 15, 16 are defined by further inner peripheral edges 17, 18 of the cover layer and the support layer, respectively. The cover layer 2 and the support layer 7 are also connected along their inner peripheral edges 17, 18 and therefore delimit the receiving space 13 as well.

Figure 2 shows a cross-section of the device in fig. 1 along II-II. As shown, the filling material 8 only partly fills the receiving space 13, as the filling material 8 comprises a layer material, such as a felt or a paper comprising an inorganic fibrous material that is soluble in a hydrous or saline environment. This has the advantage that this material can be dissolved when in the human body and is therefore not seen as a health risk for any users compared to other inorganic fibres, e.g. asbestos. Preferably, the filling material comprises at least one of aluminium oxide (AI2O3), silicon oxide (S1O2), calcium oxide (CaO) and magnesium oxide (MgO). The filling material could also have the form of loose fibres or granules or a mixture of a fibre and a powder to fully wad or stuff the receiving space.

The support layer comprises a protection layer 19, preferably comprising an aluminium alloy foil or a coated e-glass textile. The protection layer 19 protects the fibres in the support layer 7 and locks them in the device. The support layer 7 further comprises a number of layers 7’ and 7” of e-glass paper, i.e. electronic grade glass paper or a felt made of e-glass fibres. Using several layers in the support layer 7 results in an increase rigidity of the support layer 7 and therefore provides an increased support for the device 1 and improves the moisture resistance of the device simultaneously.

Figure 3 shows an exploded schematic view of an interior of a boiler 30 comprising the burner cover insulation device 1 of fig. 1. The burner cover insulation device 1 is used to protect the cover plate 21 of the boiler 30 when covering the boiler housing 31 (dashed) in which the heat exchanger (not shown) and the burner 20 are provided. The burner 20 extends through the through hole 5 of the burner cover insulation device 1. The protective layer 19 faces the cover plate 21 and the cover layer 2 faces the interior of the boiler housing 31 to shield the cover plate 21 from the heat produced by the burner. To seal the cover plate 21 and the burner housing 31, a sealing gasket 22 is provided along the peripheral edge of the cover plate 21.

Figure 4 shows a perspective view of a second embodiment of the burner cover insulation device 1 according to the invention. This second embodiment has a similar structure as the first embodiment of the device, comprising a cover layer 2 and a support layer 7 that are connected by means of stitches 3, 6 along their inner peripheral edge 9, 10 and the outer peripheral edge 12 of the cover layer. This embodiment is different from the first embodiment in that the outer peripheral edge 11 of the support layer 7 extends beyond the outer peripheral edge 12 of the cover layer 2, thereby forming a radially outwardly extending flange 23. Along the outer peripheral edge 11 of the support layer 7, a sealing element 4 is provided. This sealing element 4 comprises a silicone rubber and has a similar function as the sealing gasket 22 shown in fig. 3. The radially outwardly extending flange 23 and the sealing element 4 together form a gasket element for sealing the burner housing 31 of the boiler 30 in use to prevent any flue gasses to escape the burner housing 31 other than via a flue (not shown). The outwardly extending flange 23 may be provided with through holes for accommodating bolts or other suitable fastening means that may be used to fasten the cover plate through the burner cover insulation device to the boiler housing and/or heat exchanger.

Figure 5 shows a cross section along V-V in fig. 4 of the second embodiment of the burner cover insulation device 1 and shows a similar basic structure as the cross-section of the first embodiment in fig. 2. In this cross-section, it is shown that the support layer 7 comprises a protective layer 19 on both sides, i.e. on the side facing towards the cover layer 2 and the side facing away from the cover layer 2, to enclose the fibres of the support layer 7 in the radially extending flange 23 as well. The protective layer 19 comprise a woven textile comprising an inorganic fibrous material, such as glass fibre. The woven textile may be coated with a polyurethane coating to increase the high temperature resistance of the protective layer 19.

Figure 6 shows a perspective view of the burner cover insulation device 1 of fig. 4 arranged around a burner 20 of a boiler 30 (not shown). The device 1 is proved over the burner 20, such that the burner 20 extends through the through hole 5 of the device. The protective layer 19 (not shown) faces the cover plate 21 and the cover layer 2 is facing the interior of the burner housing 31 (not shown). The sealing element 4 provided along the outer peripheral edge 11 of the support layer 7 seals the cover plate 21 and the boiler housing 31 during use.

Thus, the invention has been described by reference to certain embodiments discussed above. It will be recognized that many modifications in addition to those described above may be made to the structures and techniques described herein without departing from the spirit and scope of the invention. Accordingly, although specific embodiments have been described, these are examples only and are not limiting upon the scope of the invention.

LIST OF PARTS 1. Burner cover insulation device 2. Cover layer 3. Mechanical connection 4. Sealing element 5. Through hole 6. Mechanical connection 7. Support layer 8. Filling material 9. Inner peripheral edge of support layer 10. Inner peripheral edge of cover layer 11. Outer peripheral edge of support layer 12. Outer peripheral edge of cover layer 13. Receiving space 14. Raised portion 15. Further through hole 16. Idem 17. Further inner peripheral edge of support layer 18. Further inner peripheral edge of cover layer 19. Protective layer 20. Burner 21. Cover plate 22. Sealing gasket 23. Radially extending flange 30. Boiler 31. Burner housing

Claims

A burner cover insulation device (1) for protecting a burner cover (21) against a boiler burner (20), the device comprising: a cover layer (2) comprising a heat-resistant inorganic fibrous material and having an outer peripheral edge (12), the heat-resistant material the cover layer comprises a heat-resistant inorganic textile layer, a support layer (7) with an outer peripheral edge (11) which extends at least to the outer peripheral edge of the cover layer, and a filling material (8) which forms a layer between the cover layer and the support layer, wherein a through hole (5) extends through the cover layer and the support layer, the through hole being delimited by inner peripheral edges (9, 10) of the cover layer and the support layer, the cover layer and the support layer being joined along at least a portion of the inner peripheral edges and along at least a part of the outer peripheral edge of the cover layer.

Device according to claim 1, wherein the cover layer and the support layer are connected adjacent to each other along at least a part of the outer peripheral edge of the cover layer to enclose a receiving space (13), which receiving space extends along at least a part of the inner peripheral edge and which receiving space is bounded by connections (3, 6) along the inner and outer peripheral edges, wherein at least a part of the receiving space is filled with the filling material, so that a raised portion (14) with respect to the outer peripheral edge of the coating is formed.

3. Device as claimed in claim 1, wherein the layer of filler material between the cover layer and the support layer extends from the inner peripheral edges to the outer peripheral edge of the cover layer, thereby forming an inner and an outer peripheral edge of the layer of filler material, so that the cover layer, the layer of filler material and the support layer are connected to each other along the inner peripheral edges and along at least the outer peripheral edges of the cover layer and the layer of filler material.

Device as claimed in any of the foregoing claims, wherein a sealing element (4) for sealing a burner housing (31) of the boiler (30) in use is provided along at least the outer peripheral edge of the support layer.

Device as claimed in any of the foregoing claims, wherein the outer peripheral edges of at least the supporting layer and the covering layer coincide, and wherein the covering layer and the supporting layer are connected along the coinciding outer peripheral edges.

The device of any one of claims 1-4, wherein the outer peripheral edge of the support layer extends beyond at least a portion of the outer peripheral edge of the cover layer, thereby forming an outwardly extending flange (23).

Device as claimed in any of the foregoing claims, wherein the continuous hole is aligned with respect to the center of the cover layer and the support layer.

Device as claimed in any of the foregoing claims, wherein the device is formed as a ring with an outer and an inner diameter, the inner diameter being determined by the continuous hole and the outer diameter being determined by the outer peripheral edge of the support layer.

Device according to claim 8, wherein the cover layer and the support layer enclose a receiving space (13), wherein the receiving space filled with filling material forms at least a part of a raised ring (14) around the through-hole.

Device as claimed in any of the foregoing claims, wherein the inner peripheral edge and the outer peripheral edge are centered with respect to each other such that a distance between the outer and inner peripheral edges is equal along a circumference of the device.

Device as claimed in any of the foregoing claims, wherein the cover layer and the support layer are connected by means of a mechanical connection (3, 6), such as sewing.

12. Device as claimed in any of the foregoing claims, wherein a side of the support layer remote from the cover layer comprises a protective layer to protect the support layer, so that the support layer is situated between the protective layer and the cover layer.

Device as claimed in any of the foregoing claims, wherein the heat-resistant material of the cover layer comprises mechanically connected fibers.

Device as claimed in any of the foregoing claims, wherein the heat-resistant inorganic textile layer is provided with a heat-resistant coating on at least one side remote from the filling material.

Device as claimed in any of the foregoing claims, wherein the heat-resistant inorganic textile layer comprises a woven silica textile.

Device as claimed in any of the foregoing claims, wherein the filling material comprises an inorganic fibrous material.

The device of claim 16, wherein the inorganic fibrous material comprises an inorganic fiber material that is soluble in water or in a saline solution.

The device of claim 16 or 17, wherein the filler material comprises at least one of aluminum oxide (Al 2 O 3), silicon oxide (Al 2 O 2), calcium oxide (CaO) and magnesium oxide (MgO).

A boiler (30) comprising a burner (20), a burner housing (31) for accommodating the burner and a heat exchanger, a cover plate (21) for covering the burner housing, and a burner cover insulating device (1) according to any one of the preceding claims for protecting the cover plate against the burner and heat exchanger, wherein the burner extends through the through hole (5) of the burner cover insulator in the burner housing, the cover layer (2) facing an interior of the burner housing and a side of the support layer (7) facing away from the cover layer faces the boiler cover plate.

Boiler according to claim 19, wherein a sealing element (4) for sealing the burner housing of the boiler in use is provided along at least the outer peripheral edge (11) of the support layer.

The boiler of claim 19 or 20, wherein the outer peripheral edge of the support layer extends beyond at least a portion of the outer peripheral edge of the cover layer, thereby forming an outwardly extending flange.

A method for manufacturing a burner cover insulation device (1) according to any one of claims 1-18, wherein the method comprises: - providing a support layer (7) and a cover layer (2), both layers having an outer peripheral edge (11, 12 wherein the cover layer comprises a heat-resistant inorganic fibrous material; - providing a filling material (8) between the support layer and the cover layer; - cutting out a continuous hole (5) extending through the support layer and the cover layer, thereby forming an inner peripheral edge (9, 10) of both the support layer and the cover layer; and - connecting the cover layer along at least a part of the outer peripheral edge and / or the inner peripheral edge thereof to the supporting layer.

A method according to claim 22, wherein after joining the cover layer along at least a part of the outer peripheral edge and / or the inner peripheral edge thereof to the support layer, a receiving space (13) is formed between the support layer and the cover layer and wherein the filling material is provide at least a portion of the receiving space to form a raised portion (14) relative to the outer peripheral edge of the cover layer.

A method according to claim 23, wherein after joining the cover layer along at least a part of the outer peripheral edge and / or the inner peripheral edge thereof to the support layer, a filling opening is provided between the support layer and the cover layer at at least one of the outer layers. and inner peripheral edge and the method further comprises filling at least a portion of the receiving space with the filling material so that the raised portion is formed relative to the outer peripheral edge of the cover layer, and closing the filling opening after filling the receiving space by connecting of the cover layer and the support layer at the filling opening.

25. Method as claimed in claim 22, wherein the filling material is provided between the cover layer and the support layer for connecting the cover layer along at least a part of the outer peripheral edge and / or the inner peripheral edge thereof to the support layer and enclosing the fill material in the formed recording room.

The method of claim 22, wherein providing the filler material between the support layer and cover layer comprises providing a layer of filler material between the support layer and the cover layer for joining the cover layer along at least a portion of the outer peripheral edge and / or the inner peripheral edge thereof to the backing layer.

27. Method as claimed in claim 26, wherein the layer of filler material between the cover layer and the support layer extends from the inner peripheral edge to the outer peripheral edge of the cover layer, thereby forming an inner and an outer peripheral edge of the layer of filler material, wherein the connection of the cover layer along at least a portion of the outer peripheral edge and / or the inner peripheral edge thereof on the support layer comprises joining the cover layer, the filling material layer and the supporting layer together along the inner peripheral edges thereof and along at least the outer peripheral edges of the covering layer and the filling material layer.

A method according to claim 22, comprising providing the filling layer between the supporting layer and the covering layer, but after connecting the covering layer along at least a part of the outer peripheral edge and / or the inner peripheral edge thereof to the supporting layer of the device in a mold so that during filling the receiving space with filling material the raised part takes on the shape of the mold.

A method according to any one of claims 22-28, comprising providing at least the outer peripheral edge (11) of the support layer with a sealing element (4) for sealing a burner housing of a boiler in use.