GB2432648A

GB2432648A - Thermal insulation, edge protection

Info

Publication number: GB2432648A
Application number: GB0623392A
Authority: GB
Inventors: Frank Muelhaupt; Daniel Oeschger; Thomas Hediger
Original assignee: ABB Turbo Systems AG
Current assignee: Accelleron Industries AG
Priority date: 2005-11-23
Filing date: 2006-11-23
Publication date: 2007-05-30
Anticipated expiration: 2026-11-23
Also published as: EP1790832A1; GB0623392D0; GB2432648B

Abstract

The insulation segment has insulation core (1) with a base area (11), an external surface (12), an edge area (13) and means for protecting the insulation core in the edge area. The means for protecting the insulation core has an edge protection band (32), which sheaths the insulation core in the edge area. The edge protection band contains a glass fiber coating. By virtue of the edge protection strip the edges of the insulation segments cannot fray during assembly or dismantling or, on the other hand, during operation. In this way, it is possible to prevent losses in the pre-stressing at the interfaces of a plurality of insulation segments arranged adjacent to one another. The insulation may be used on a turbo-charger housing.

Description

M&C Folio: EPP96263 1 2432648

TURBO-CHARGER INSULATION

Description

Technical Field

The invention relates to the field of thermal insulation of hot surfaces, for example of the surfaces of turbo-chargers for supercharged internal-combustion engines. It relates to an insulation segment for the thermal insulation of a hot surface, in particular for the thermal insulation of housings of exhaust-gas turbines, as well as to an exhaust-gas turbo-charger with a housing with insulation segments of this type.

Prior art

There are various reasons why a hot surface of a machine or a vehicle has to be covered with thermal insulation. For example in the field of exhaust-gas turbo-chargers which are used in the engine rooms of ocean-going ships, in other vehicles operated with fuel or in stationary plants, there are various international safety standards which stipulate a thermal insulation. The Convention for the Safety of Life at Sea' (SOLAS) for example states that surfaces of apparatus in the engine rooms of ocean-going ships, which can be at a surface temperature of more than 220 C, have to be adequately insulated.

The insulation generally used for turbo-chargers is formed from a plurality of insulation segments arranged adjacent to one another. An insulation segment of this type, illustrated in Fig. 1, comprises an insulation core (1) of a glass-fibre or silicate-fibre mat which is fastened to a support plate (5). In order to protect the fibrous core material and to reflect the heat, a metal foil (2), for example of aluminium or special steel, is attached to the outer face (12) of the insulation core facing the hot housing part which is to be thermally insulated. The individual insulation segments are fastened to the housing of the turbo-charger by way of a substructure, so that the turbo-charger and the insulation form one unit. In this case the individual insulation segments are arranged adjacent to one another in such a way that their lateral edges are pressed against one another with pre-stressing. In the case of conventional insulation segments the lateral edges are provided with a temperature-resistant coat of paint (31).

In the case of conventional insulations of turbo-chargers the coat of paint is intended to protect the assembly fitters from direct contact with the insulation fibres, in order to avoid possible skin irritation. In addition, the coat of paint is intended to prevent the edges of the individual insulation segments from fraying during the assembly or dismantling or even individual insulation fibres or a plurality of insulation fibres from becoming detached from the core as a result of the vibrations of the turbo-charger. Such a fraying or thinning of the core would lead to a loss of pre-tensioning between the individual insulation segments arranged adjacent to one another and, in an extreme case, to a loss of insulation and thus to a rise in temperature on the exposed surface.

After prolonged operation it can happen that the coat of paint becomes detached from the insulation segment as a result of rubbing or on account of a high degree of dampness or fluctuating temperatures. If, as a result, the requirements are no longer met, the insulation segments have to be replaced.

Summary of the Invention

The object of the present invention is to provide an improved edge protection for insulation segments for the thermal insulation of hot surfaces.

The long-wearing and highly stressed edge regions of the insulation segments are protected according to the invention by an edge protection strip.

By virtue of the edge protection strip the edges of the insulation segments cannot fray during assembly or dismantling or, on the other hand, on account of vibrations caused by operation. In this way, it is possible to prevent losses in the pre-stressing at the interfaces of a plurality of insulation segments arranged adjacent to one another and to ensure the functioning of the insulation.

In addition, the assembly fitters are protected in a lasting manner from direct contact with the insulation fibres even after prolonged operation of a machine, for example an exhaust-gas turbo-charger, covered with insulation segments of this type.

Further advantages are set out in the dependent Claims.

Brief Description of the Drawings

The insulation segment according to the invention is explained in greater detail below with reference to drawings. In the drawings Fig. 1 shows an insulation segment according to the prior art with a coating of paint as an edge protection; Fig. 2 shows a first embodiment according to the invention of an insulation segment with an embracing edge protection strip; Fig. 3 shows a second embodiment according to the invention of an insulation segment with an edge protection strip pressed under a cover foil, and Fig. 4 shows two arrangements of two insulation segments according to the invention.

Manner of Implementing the Invention The insulation segments according to the invention are described below with refe-rence to use in order to insulate the surfaces of exhaust-gas turbo-chargers. However, the invention, as claimed by the Claims, covers insulation segments for all possible uses.

In particular, those parts of turbo-charger housings with the hottest surface tempera-tures, for example the gas-inlet or gas-outlet housing near the turbine, are covered by a plurality of insulation segments arranged adjacent to one another. The insulation segments are fastened to the housing of the turbo-charger by means of a substructure.

In the assembled state the turbo-charger and the insulation form one unit. A conventional insulation segment for the thermal insulation of an exhaust-gas turbo-charger is illustrated in the first of the three Figures. In order that an insulation segment may be dimensionally stable even in the non-assembled state, the core I of the insula-tion segment is arranged at least in part with its bottom face 11 on a support-plate segment 5. In the mounted state the support plate then forms the outer wrapping of the insulation. The insulation core can then be secured by adhesion, riveted, sewn or fastened in another manner to the supportplate segment. In the drawings of the present application the insulation core is fastened to the support plate by means of a spring tension plate 62 in each case which is attached to a fastening pin 61 welded firmly to the support-plate segment. The spring tension plate can be made round or angular. The insulation core usually comprises a glass-fibre or silicate-fibre mat. As already mentioned in the introduction, in order to protect the soft, fibrous insulation core 1 and to reflect the heat, it is usual in the case of conventional insulation segments for the outer surface of the said insulation core I facing the housing part 7 to be insulated to be covered with a metal foil 2, for example of aluminium or special steel. In addition, the insulation segments cut to the desired dimensions are sealed on the lateral edge regions by means of edge protection paint 31.

In the embodiments of the insulation segments according to the invention as shown in Fig. 2 and Fig. 3, in the region of the lateral edges the insulation core is embraced by an edge protection strip 32 instead of or in addition to the conventional layer of paint 31.

In the first embodiment as shown in Fig. 2 the edge protection strip 32 is arranged above a coating of paint 31 used in the case of conventional insulation segments. If a coating of paint 31 of this type is used in addition to the edge protection strip, it protects the insulation core until and during the assembly of the edge protection strip. If the paint is given a component of glue, it can also additionally perform an adhesive function and be used for improved fastening as well as a complete abutment of the edge protection strip on the insulation core.

The edge protection strip 32 is pressed over the edge region of the cover foil 2 on the outside 12 of the insulation core in the region of the lateral edge 13 illustrated. This arrangement permits a simple assembly of the edge protection strip on the insulation core which is already provided with a cover foil. Alternatively, however, the edge protection strip 32 can also be pressed between the outer face 12 of the insulation core and the cover foil 2 before being fastened to the insulation core, as shown in Fig. 3. In both cases it is possible to ensure, with an overlapping of the cover foil and the edge protection strip, that the outer face of the insulation core is covered without gaps.

In order to be able to build up pre-tensioning between the individual insulation cores when a plurality of insulation segments are arranged adjacent to one another, the insulation segments overlap the support plates slightly. In this case, as shown in the upper half of Fig. 4, the two insulation cores 1 arranged adjacent to each other can project beyond their support plates 5. Alternatively, as shown in the lower half of Fig. 4, one of the two insulation segments can be set back with respect to its associated support plate 5, whilst the other one projects beyond its support plate. In this way, depending upon the use, the insulation segment can be positioned flush on the support plate, or, on the other hand, as indicated in Fig. 2, it can project to a greater or lesser extent beyond the support plate 5. In each case the edge protection strip 32 is advan-tageously made sufficiently long for it to be clamped on the side of the bottom face 11 of the insulation core between the insulation core and the support plate 5 and for the insulation core not to be exposed between the edge protection strip and the support plate.

During assembly, the edge protection strip is advantageously secured first to the bottom face of the insulation core and then, together with the insulation core, to the support plate. For fastening to the insulation core, the edge protection strip surrounding the edge region 13 can be sewn on by means of a continuous seam 42. If the edge protection strip is already bent into the correct shape before assembly, then the fastening can easily be carried out with a single seam.

If, however, the edge protection strip first has to be positioned on the outer face and then bent and fastened in a definitive marmer for manufacturing reasons, the embodi-ment as shown in Fig. 3 is possible. In this case the edge protection strip 32 is fixed in a first step on the insulation core with a first seam 41 from the outer face 12. During this, part of the cover foil 2 is lifted, the edge protection strip 32 is pressed between the cover foil and the insulation core and after that the cover foil is firmly sewn onto the edge protection strip by means of a first seam 41. After that, the edge protection strip bent around the edge region 13 of the insulation core is firmly sewn on in a definitive maimer by means of a second seam 42. The second seam can be positioned in such a way that it embraces the edge protection strip on both sides of the insulation core. If the edge protection strip 32 extends on the side of the outer face 12 but between the cover foil 2 and the insulation core 1, the second seam 42 can be positioned in such a way that on the side of the outer face it extends only through the cover foil. In this way it is possible to prevent the cover foil from becoming detached from the insulation core during operation.

The fastening pins 61 used for fastening the insulation core to the plate segments 5 are advantageously arranged close to the edge of the insulation core. This prevents the insulation mats -pressed against each other with pre-tensioning -of two insulation segments in the contact region from becoming detached from the plate segment. During the fastening to the plate segments, the already sewn insulation core is first placed on the fastening pins 61 and is then fixed with the spring tension plates 62.

List of References 1 insulation core, insulation mat 11 bottom face 12 outer face 13 edge region 2 cover foil 31 edge protection paint 32 edge protection strip 41 outer seam 42 inner seam support-plate segment 61 fastening pin 62 spring tension plate 7 housing part

Claims

Claims: 1. An insulation segment for the thermal insulation of a hot

surface, comprising an insulation core (1) with a bottom face (11), an outer face (12) and an edge region (13) as well as means for protecting the insulation core in the edge region, charac-terized in that the means for protecting the insulation core comprise an edge protection strip (32) which embraces the insulation core in the edge region (13).

2. An insulation segment according to Claim 1, characterized in that the edge protection strip (32) contains a glass-fibre tissue.

3. An insulation segment according to one of Claims I or 2, characterized in that the edge protection strip (32) is inserted into the region of the outer face (12) between the insulation core (1) and a cover foil (2) covering the outer face (12) of the insulation core at least in part.

4. An insulation segment according to any one of Claims 1 to 3, characterized in that the insulation core (1) together with the bottom face (11) rests at least in part on a support plate (5), and the edge protection strip (32) is inserted into the region of the bottom face (11) between the insulation core (1) and the plate segment (5).

5. An insulation segment according to any one of Claims I to 4, characterized in that the edge protection strip (32) is fastened to the insulation core (1) by means of at least one seam (41, 42).

6. An insulation segment according to Claim 5, characterized in that the edge protection strip (32) is fastened to the insulation core (I) by means of a first seam (41) on the side of the outer face (12) and by means of a second seam (42) on the side of the bottom face (11).

7. An insulation segment according to one of Claims 5 or 6, characterized in that the edge protection strip (32) is fastened to the insulation core (1) by means of a seam (42) extending from the side of the outer face (12) to the side of the bottom face (Ii).

8. An insulation segment according to any one of Claims 1 to 7, characterized in that a coating of paint (31) is applied to the insulation core (1) between the insulation core (1) and the edge protection strip (32).

9. An insulation segment according to Claim 8, characterized in that the coating of paint (31) contains an adhesive component 10. A turbo-charger with a housing, characterized by insulation segments according to any one of Claims 1 to 9 which cover the housing at least in part.

11. A method of fastening an edge protection strip (32) to an insulation core (1) of an insulation segment, in which method -the edge protection strip (32) is arranged on an outer face (12) of the insulation core (1) adjacent to an edge region (13); -the edge protection strip (32) is extended around the edge region (13) as far as a bottom face (11) arranged adjacent to the edge region and opposite the outer face, and the edge protection strip (32) is fastened to the insulation core (1) on the side of the outer face (12) and on the side of the bottom face (11) by means of at least one seam (41, 42) altogether.

12. A fastening method according to Claim II, in which -the edge protection strip (32) is pressed between the insulation core (1) and a cover foil (2) covering the insulation core towards the outside on the side of the outer face (12) of the insulation core.

13. A fastening method according to one of Claims 11 or 12, in which -the edge protection strip (32) is fastened to the insulation core (1) by means of a first seam (41) on the side of the outer face (12) and by means of a second seam (42) on the side of the bottom face (11).