CH687627A5 - Heat insulating construction or lighting element - Google Patents

Abstract

(A) A process for producing a sealed joint between a glass surface and a metallic material involves metal coating of the glass surface by a plasma process. (B) A heat insulating construction and/or lighting element consists of two or more parallel wall elements having interposed support elements and forming an evacuatable interspace with a sealed joint at the edge region. The novelty is that the interspace is formed by a gap between the wall elements which is less than the free path length of gas molecules in the fine vacuum range of 1-10 power(-3) mbar required for cancelling heat conduction. Relative displacement of the wall elements in the edge region is absorbed by a seal. (C) A process and an appts. for prodn. of the construction and/or lighting element are also claimed.

Description

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description

The invention relates to a heat-insulating structural and / or light element according to the preamble of claim 1.

For decades, the double and triple-glazed window on buildings after the front window has proven itself, which over the course of time through additional measures such as vapor deposition with an infrared reflecting layer and filling with noble gases with regard to the insulation effect to a k-value of 1.3 W. / m2 K could be improved. This value is still unsatisfactory compared to well-insulated building exterior walls.

Even lower k values (1.0 W / m2 K) are achieved with insulating glass windows, which are stretched between the glass panes and have transparent foils coated with infrared rays. The foils cause convection, i.e. heat transfer due to moving air is severely hampered. To avoid glass breakage, the high pressure that builds up when the glass panes are heated must be able to escape from the dense cavity of the windows, which are up to 100 mm thick. An additionally provided filter has the effect that the incoming new air is dehumidified in order to prevent fogging of the glass panes in the cavity of the window. This construction allows a more favorable k-value, but impairs the light transmission of the window due to the many reflection layers. In addition, it is voluminous and complex.

Even better k-values can be achieved with vacuum-insulated light elements, since as the vacuum increases in a cavity, the convection of the air and then the heat conduction are largely eliminated. In addition, glass is one of the most suitable materials that can maintain a vacuum for decades.

Vacuum-insulated light elements also achieve a positive heat balance in winter, because the heat energy loss in a window is smaller than the energy entering through the light.

The advantage of an evacuated light element is that sound cannot propagate in a vacuum.

It is also advantageous if no condensate can form in an evacuated cavity.

In addition, an infrared reflecting layer, for example silver vapor deposition, is uniquely protected against oxidation in a vacuum, which largely prevents it from becoming blind.

It is therefore an undisputed fact that a vacuum-insulated building and / or lighting element would bring great advantages in use.

However, these existing findings have not been enough to achieve economic success.

Even in a double glazing unit of a vacuum housing according to DE-A 2 755 013, which is designed in the manner described at the outset, a relative movement occurs due to the temperature differences of the glass panes spaced apart by a plurality of spacing devices. For this reason, the spacing devices each have opposite bearing elements on the inside of the glass panes, into which a spacer pin, which is spherical at both ends, engages, which enables the relative movement of the glass panes in one direction. At the edges, the vacuum housing is provided with a film sealing element connected between the glass panes and with these on the inside.

The construction of the spacing device forces a relatively large distance between the glass panes, so that a high expenditure of energy is required to produce an insulating vacuum, or vice versa, a sufficient insulation value cannot be obtained with a low vacuum. There are also concerns regarding the film sealing element used, which due to its arrangement and design when using a vacuum between the glass panes cannot withstand an external pressure; the film sealing element is peeled off from the glass panes.

In the case of a heat-insulating window glass according to EP-A 0 047 725, the glass panes have a low melting point, so that the supporting elements located opposite one another, which form an intermediate space, fuse to one another when heated accordingly. The edges of the glass panes are fused with narrow glass strips to separate the evacuated space from the surroundings. The glass panes should have a distance of 0.1 to 0.3 mm and the tight space a vacuum lower than 0.1 mbar respectively. Have 10_1 mbar. With regard to the task, the risk of implosion should be reduced by providing between 30 and 100 support elements between the glass panes on each cm2. These requirements do not allow a satisfactory, physically based insulation effect of the window disclosed here, if only because the vacuum to be applied of at least 10 ~ 1 mbar and the distance between the glass panes of 0.1 to 0.3 mm are based on assumptions that cannot be brought into any physical context. Furthermore, the extent of the use of support elements is selected to be so high that heat transfer between the glass panes will take place, which is further favored by the glass support elements. The rigid connections of the glass panes at the edges of the window are also unsuitable in order to be able to absorb or compensate for the constantly occurring different surface expansions of the glass panes.

Furthermore, a component with high insulating capacity has become known from German Offenlegungsschrift 2,520,062, in which at least one of the two boundary surfaces arranged at a distance is translucent or transparent and the boundary surfaces are supported against one another by supporting elements. In the context of the information disclosed here, a component is proposed, the boundary surfaces of which are due to the cylindrical or adhesive to be set up

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spherical support elements have a distance of several millimeters. The remark that a small distance between the boundary surfaces results in a better insulation effect is unfounded due to the information provided and is based on assumptions that lack economic considerations and knowledge as well as lack of constructive design features. The special configuration of the connection at the edges of the component formed with a small distance between the boundary surfaces is also unsolved in such a solution. Also unrecognized is the solution that leads to the avoidance of the recognizability of the individual support elements, if, as e thought, light tulle curtains or raindrops appear considerably stronger and more irregular.

According to the final report of a Swiss research project No. 1093.1, experiments were carried out in the years 1983 to 1985 in the development of an "evacuated double window with extremely high thermal insulation". The experiments carried out according to DOS 2 520 062 and the American patent specification 3 916 871 did not yield any informative and satisfactory knowledge about the design as well as the economical production of an evacuated double window. Even if the tightness of the intermediate space could have been solved, a window or a glass door with the support elements that impair the clear view is still undesirable and has therefore led to the early termination of the research project.

In the thermal insulation of buildings, the windows of previous constructions form the Archilles tendon, which must be removed. Vacuum technology should make it possible to open windows with a positive energy balance, i.e. with k values below 0.5 W / m2. In winter, the incoming light energy would be greater than the exiting heat loss, which means that a vacuum window on the north side of a house could represent a kind of heating wall during the day, even though it is not illuminated by the sun.

With the simultaneous use of vacuum-insulated light elements as windows and facade elements, conventional building heating could be dispensed with in many cases, since a translucent building skin can transfer enough light energy in the form of heat into the building interior, i.e. represents a kind of heat trap.

The building walls serve as heat stores during the night until the light heating is activated again in the morning.

In summer, the vacuum-insulated windows and facade elements equipped with shading devices create a cooler building, even with excellent sound insulation values, since sound cannot propagate in a vacuum.

However, despite great efforts, it has so far not been possible to find a satisfactory solution.

According to the prior art, the main obstacle to a market launch is the grid-like arrangement, which is very disruptive to the window view

Support elements, such as balls or standing bolts, which are rejected by construction practice. There is also a permanent risk of accident due to glass breakage due to implosion of evacuated windows.

In addition, it has so far not been possible to position these known balls or bolts precisely in large numbers in a grid-like manner on a glass surface.

Another obstacle to implementation was the high vacuum used in order to achieve a sufficient insulating effect, which cannot be maintained over long periods due to the constant evaporation of the glass surfaces.

The component according to German Offenlegungsschrift 2 520 062 has the disadvantages of the optically disruptive supporting elements. The publication of a research work by SERI, Solar Energy Research Institute, Golden, Colorado USA in the journal "In Rewiev" from January 1985 shows that no progress has been made in the recent past.

This publication shows two glass plates with a thickness of 3 mm, between which spherical supports with a diameter of 4 mm which disturbs the view are arranged in a grid. The required high vacuum of 1.3 x 10 ~ 5 mbar poses great difficulties in maintaining it for decades. There is also a risk of implosion if the glass spacing is provided.

The object of the invention is therefore to provide a heat-insulating structural and / or light element of the type mentioned, which largely prevents heat loss by a permanent vacuum and whose high insulating capacity can be produced within the scope of industrial possibilities under economic conditions, and a clear transparency guaranteed.

According to the invention, this object is achieved according to the features of the characterizing part of patent claim 1.

This definition guarantees the possibility of a high insulating ability of a building and / or light element in the fine vacuum range and a permanent maintenance of the vacuum in the space formed by the wall elements which are tightly connected in the edge area. The considerably more complex production in a high vacuum can be avoided without reducing the insulating ability and impairing the possibility of a clear view, quite the contrary.

The evaporation of the walls of the evacuated space that occurs in the high vacuum area is largely eliminated in the fine vacuum area and the capacity for maintaining the vacuum is thereby increased considerably.

The present inventive concept is based among other things. to the physical fact that the thermal conductivity of gases is practically eliminated if the free path of the existing gas molecules is greater than the distance between the cold and warm wall of an evacuated room.

The free path length of the gas molecules is that

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vacuum generated by the vacuum proportional. The consequence of this law is that the smaller the distance from the wall, the less to evacuate in order to reduce or prevent heat conduction in the gas. For example, the mean free path of the air molecules at a vacuum of 10-1 mbar is approximately 0.6 mm or at 1 mbar approximately 0.06 mm. It should be noted that the air molecules in a vacuum room not only move vertically from wall to wall, but in all directions of the room.

The practical application of this rule leads to the smallest possible distance between the wall elements, so that a technical implementation is just still possible. Depending on the surface condition, the distance between the wall elements or glass panes will be between 0.05 and 0.5 mm.

Of course, a gap up to 1 mm apart is covered by the present inventive concept as a poorer version.

This knowledge gives rise to an undreamt-of advantage in that the support elements between glass panes can be dimensioned so small that they cannot be detected by the naked eye at a distance of less than one meter, or only very poorly. It proves to be particularly advantageous if the support elements are fastened to at least one wall element, as a result of which their production and attachment can be carried out in a simple manner.

The support elements are expediently designed as flat disks, as a result of which a small distance between the wall elements of the intermediate space can be produced from flat sheet or strip material or cylindrical or prismatic materials.

The support elements are advantageously formed from a transparent material in order to promote undisturbed viewing.

This material is preferably made softer than the wall elements, in order to be able to avoid injury or damage to the surface of the wall elements because of the wall elements shifting due to heat differences. Here plastic, for example polyester or teflon, is suitable as a particularly inexpensive material with good sliding properties.

The distance between the supports is primarily determined by your own and the strength properties of the wall elements and must be used accordingly. While distances of approx. 1 cm and less are provided between the support elements in the window glass pane according to European patent specification 0 047 725, in the interest of a low heat transfer the support elements cover a maximum of 1% (one per thousand) of the total area of the evacuated building and / or light element. The tests have shown that a significantly lower value is possible, for example 0.3% (zero-point per mille).

To prevent infrared radiation, it is advantageous if at least one layer of gold, silver or other suitable materials reflecting the infrared rays is provided within the intermediate space.

Due to the changing temperature differences on both sides of the building and / or light element and the resulting mutual displacements of the wall elements, it is useful if the support elements with a wall element, e.g. by gluing, are firmly connected.

Of particular importance in the implementation of a constructional and / or lighting element constructed from an economic point of view is the coherent technical functionality of the subtasks of the problem area that is to be solved. The demand for a technically less demanding vacuum in a space with a minimal distance and the resulting mutual displacements of the wall parts in their directions of extension require a combination of solution features that were obviously not recognized even in the known development attempts.

Furthermore, the insulating effect can be improved by a further or a plurality of wall elements arranged in a row, the arrangement of the support elements of the one wall element advantageously being offset relative to the other in order to further obstruct the path of heat conduction. A building and / or lighting element formed from three wall elements made it possible for a prototype designed according to the teaching of this invention to achieve an unprecedented k value of 0.31 W / m2 K. Components without the requirement for light transmission are also in one with a multi-layer construction relatively thin design.

Getter agents which are connected to the vacuum space can be arranged for a permanent absorption of residual gases or vapors which only occur weakly in the proposed vacuum range. These getter means increase the reliability of the vacuum and can have a decisive influence on the functionality of the component and / or light element. Getter agents that have to be heated periodically are exposed to the sun at the edge of the transparent glass panes.

The tight connection in the end region of the structural and / or light element, which accommodates the mutual displacement of the wall elements, is flexible, elastic and / or flexible, in order to be able to absorb the different changes in the extension of the wall elements, particularly in the case of flat interspaces due to heat differences. The connection to the wall elements can be sealed by means of glass welding, soldering, gluing or vulcanizing a gas-tight, also rubber-like material. The seal can also be designed in several stages and thus offers the advantage of greater security.

Melting, soldering or gluing can be used as a gas-tight connection with the wall elements.

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be det. Getter agents can be inserted under the metal foil.

So that the cavity for the getter is given a higher resistance to the atmospheric external pressure, a C-profile open towards the edge of the structural and / or light element can be inserted into the cavity. This allows the cavity to be used for placing getter agents.

The getter means can also be provided outside of the structural and / or light element, in a container communicating with the evacuated space.

As a further possibility for sealing the intermediate space, the wall elements can be formed on the inside with sealing grooves running at least approximately parallel to the edges.

The invention is illustrated, for example, on the basis of the embodiments shown in the drawing and subsequently discussed. Show it:

1 is a plan view of the constructional and / or light element according to the invention,

2 shows a cross section through the structural and / or light element,

3 shows an enlarged cross section through a construction and / or light element,

4 shows an enlarged cross section through a construction and / or light element,

5 shows an enlarged cross section through a structural and / or light element,

6 is a partially enlarged cross section through a structural and / or light element,

7 shows an enlarged cross section through a structural and / or light element,

Fig. 8 is a partially enlarged cross section through a construction and / or light element.

1 shows a construction and / or lighting element with the arrangement of the support elements 2 between, for example, two wall elements 1.

In Fig. 2 this construction and / or light element with the space 3 is shown in cross section. Fig. 3 shows a multi-stage edge seal made of an elastic, rubber-like material. Getters 5 are provided between the wall elements 1 between the seal 4 located in the grooves 6. The channels between the seals 4 are evacuated and mutually sealed, so that the failure of a seal 4 has no noticeable influence on the next stage. In Fig. 4, a flexible edge seal made of a thin metal foil 7 is shown, which is soldered or glued with its edges to the inside of the wall elements 1 and the remaining part of which lies folded and protrudes beyond the edge of the structural and / or light element. Getter agents which are heated by the light radiation can be arranged in the form of a thin covering or tape in the evacuated space 3.

FIG. 5 illustrates a flexible edge seal as in FIG. 4 with the difference of a larger one intended for receiving the getter means

Space. This is achieved by inserting a pressure-resistant C-profile 9, which is enclosed by the T-shaped metal foil. U-profile 10 serves as mechanical protection.

6 shows a flexible edge seal made of a two-part metal profile 11. The legs are vacuum-sealed or soldered to the wall elements 1, as is the separating point 12 of the two-part metal profile. This application is also possible for the embodiment according to FIGS. 3 and 4.

7 illustrates an edge seal made of a vulcanized-on material surrounding the wall elements 1.

FIG. 8 shows an edge seal according to FIGS. 3 and 7 with a vacuum-tight square tube frame 14, which communicates with the intermediate space 3 by means of a connection. The cavity of the tube is provided with gettering agents. A vacuum valve 16 can be attached to this tubular frame. To cancel the infrared radiation, the surface of the wall elements 1 facing the intermediate space 3 can be provided with a silver, gold or other vapor deposition layer serving the same purpose.

In addition, it is possible to interchangeably attach the getter without the vacuum suffering during the exchange.

Furthermore, the vacuum-insulated construction and / or light elements can be designed with a valve or the like, which allows to be re-evacuated after a very long time, but this will hardly be necessary since getter agents permanently absorb any outgassing of the wall elements 1 and the seals. This problem occurs primarily in the high vacuum range, but is largely mitigated in the present case.

Vacuum-insulated components and / or light elements according to the idea of the invention are also suitable as inexpensive thin-layer insulation for refrigerators, freezers, cold rooms, etc., and wherever high thermal insulation is to be achieved with the smallest space requirement. Instead of glass panels, metal plates can be used in any number of layers, so that with a thickness of approx. 10 mm, k values of less than 0.1 W / m2 can be achieved. An even better k value is achieved by arranging infrared-reflecting foils in the micro-thin vacuum layers 3.

Claims (18)

Claims 1. Heat-insulating construction and / or light element, consisting of at least two, at least approximately parallel wall elements, which are held at a mutual distance by supporting elements arranged between them and to form an evacuated space reducing the heat conduction in its edge region by means of a mutual displacement of the wall elements receiving connection are tightly connected to one another, characterized in that the distance between the wall elements (1) is smaller than the free path length of the gas molecules in the vacuum required to cancel the heat conduction. 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 5 9 CH 687 627 A5 10th Umbereich between at least 1 and 10 ~ 2 mbar, and that the connection is a deformable seal attached to the edge of the wall elements (1). 2. Construction and / or light element according to claim 1, characterized in that the seal is formed by a metallic foil. 3. Construction and / or light element according to claim 1 or 2, characterized in that the distance between the wall elements (1) of the intermediate space (3) is a maximum of 0.5 mm. 4. Construction and / or light element according to claim 3, characterized in that the support elements (2) are attached to at least one wall element (1). 5. Construction and / or light element according to claim 4, characterized in that the height of the support elements (2) is smaller than thick. 6. Construction and / or light element according to claim 5, characterized in that the support elements (2) are designed as flat disks. 7. Construction and / or light element according to one of claims 4 to 6, characterized in that the support elements (2) are formed from a transparent material. 8. Construction and / or light element according to one of claims 4 to 7, characterized in that the support elements (2) are softer than the wall elements (1). 9. Construction and / or light element according to one of claims 3 to 8, characterized in that the support elements (2) between the wall elements (1) cover a maximum of 1% (one per thousand) of the total area of the construction and / or light element. ken. 10. Construction and / or light element according to one of claims 1 to 9, characterized in that this within the evacuated space (3) is provided with at least one layer reflecting the infrared radiation. 11. Construction and / or light element according to one of claims 1 to 10, characterized in that getter means (5) connected to the vacuum are provided. 12. Construction and / or light element according to one of claims 1 to 11, characterized in that the edge seal is formed in several stages and has mutually sealed, evacuated channels. 13. Building and / or lighting element according to one of claims 1 to 12, characterized in that the seal comprises the wall elements (1) in a U-shape. 14. Building and / or lighting element according to one of claims 1 to 12, characterized in that the seal is connected laterally to the inside of the wall elements (1) and with a protruding beyond the edge of the wall elements (1) an intermediate part, a folded, forms a T-shaped cross-sectional profile lying against the edge of the structural and / or light element. 15. Construction and / or lighting element according to one of claims 1 to 14, characterized in that the wall elements (1) are formed on the inside with at least approximately parallel to the edges sealing grooves (6). 16. Construction and / or lighting element according to one of the Claims 1 to 15, characterized in that at least one of the wall elements (1) is formed with a recessed edge in relation to the other wall elements (1). 17. Construction and / or light element according to one of claims 1 to 16, characterized in that the edge seal is formed by a shrinkable or corrugated film (7) transverse to the extension of the wall elements (1), the edges of which are connected to the wall elements (1) are connected. 18. Construction and / or lighting element according to one of claims 1 to 17, characterized in that the wall elements (1) are formed from glass. 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 6