Indirect indicator of inert gas leaks

Abstract

This invention provides an indirect indicator for detecting inert gas leaks in double-glazed glass units. [Solution] The device comprises a cover 1 on which a housing 2 with a selective layer is arranged, which is configured as an independent three-dimensional structure intended to be placed in or near the internal gas space of a double-glazed unit, and contains a photochemical compound 3 whose optical properties change in response to the presence of a gas other than an inert gas, and the cover is provided with an optically readable area 6 that can visually indicate when the inert gas concentration has fallen below a specified threshold. A medium for ensuring the reaction conditions of the photochemical compound, in particular a water source 4 for ensuring the function of the photochemical compound, is located within the cover or housing. Stability against ultraviolet irradiation and thermal cycling from -40 to +80°C is ensured.

Description

Technical Field

[0001] The technical solution relates in particular to the manufacture and quality control of multi-pane glass units and to the filling of inert gases into them.

Background Art

[0002] Currently, in order to indicate the concentration of inert gas in the cavity of a multi-pane glass unit, complex and expensive devices operating on the principle of spectrofluorimetric analysis are used. These devices require generating an electric discharge through the glass pane and then evaluating the spectrum of the emitted light. Such a solution is highly technically demanding, is easily affected by the type of treatment of the glass surface (e.g., coating), and in the case of multi-chamber glass, the measurement itself is often impossible.

[0003] Furthermore, oxygen indicators based on the chemical reaction between a dye and oxygen are known, such as the system (Patent US4169811) developed by Mitsubishi Gas Chemical Co., Ltd. These indicators change color according to the presence of oxygen and are used to confirm the airtightness of food packaging. However, the above-mentioned systems are not designed for the environment of multi-pane glass units where long-term exposure to ultraviolet irradiation and large temperature fluctuations occur, and they cannot reliably indicate inert gas leakage under these conditions. At the same time, their structures and chemical compositions do not allow adapting the measurement range to the extremely low oxygen concentration characteristic of the cavity of multi-pane glass units, so it is necessary to improve both the display scale itself and the stability of the system against optical and thermal stresses.

[0004] (Summary of the Technical Solution) The objective of the technical solution according to this invention is to create an indirect indicator for inert gas leaks that can be directly placed in the gap of a double-glazed glass unit and can directly, simply, and reliably control the integrity of the gas filling within the double-glazed glass unit in a visually readable manner without requiring a complex measuring device.

[0005] The essence of the solution for indicating inert gas concentration is a device for indicating the concentration change of atmospheric gas, particularly oxygen or carbon dioxide, that gradually replaces the original inert gas after the airtightness of the void is compromised. The indicator is placed directly within the void of the double-glazed unit, particularly in the area adjacent to or near the spacer frame, or directly integrated into the inter-pane frame. The indicator includes an optically readable layer or element whose color or other optical properties change in response to changes in the concentration of a gas other than oxygen or the inert gas. The change in optical properties is based on oxidation-reduction reactions, fluorescence reactions, photoluminescence reactions, or other photochemical reactions, and the required level of sensitivity can be adapted by adjusting the reaction measurement scale so that the indicator reacts to the oxygen concentration typical of the void in the double-glazed unit. To ensure long-term functionality, the reaction layer is stabilized against ultraviolet irradiation and temperature cycling, thereby ensuring the service life of the double-glazed unit, i.e., an operating life equivalent to several decades. The moment the concentration of the atmospheric gas reaches a predetermined level, the indicator optically changes color or other optical properties, thereby indicating that the concentration of the inert gas has fallen below the required level.

[0006] "Indicator" means a housing, capsule, or similar three-dimensional body, the housing having a gas-permeable element, preferably a film, foil, or porous layer, on at least part of its walls, which allows for the selective diffusion of oxygen or other target gases from the internal gas space of the double-glazed unit into the microenvironment of the housing, while limiting the escape of media, particularly moisture, that ensure the reaction conditions of the photochemical compound. The housing includes the indicator element and may optionally include an oxygen or other target gas absorbing element, and may further include an observation cover that forms an external envelope of the device and simultaneously defines an optical interface for reading the indication. The observation cover may be formed as a separate component or as an integral part of the housing. The indicator element is positioned in an optically accessible portion of the housing so that its visual state can be observed through at least one glass of the double-glazed unit. The indicator can be reinforced with an oxygen absorbing element, which is positioned separately from the indicator element in the same microenvironment, and which preferentially absorbs oxygen or other target gases diffusing into the microenvironment, thereby suppressing the indicator's response to oxygen or other target gases for short periods or in limited quantities. The indicator can be attached to the inner surface of the glass or to the spacer frame by adhesive bonding, mechanical fastening, or other appropriate means. [Brief explanation of the drawing]

[0007] The technical solutions will be further explained with reference to the drawings. [Figure 1] A schematic diagram illustrates an exemplary arrangement of gas indicators. [Figure 2] A schematic diagram illustrates an exemplary arrangement of gas indicators. [Modes for carrying out the invention]

[0008] (Examples of technical solutions) **Example 1** An indirect indicator of inert gas leakage from the void environment of an insulating double or triple-glazed structure comprises a cover (1) in which a housing (2) having a selective layer is arranged, the layer containing a photochemical compound (3) which is guaranteed to change visually when the concentration of the inert gas decreases. Furthermore, it includes a source (4) of a medium to ensure the reaction conditions of the photochemical compound, in particular moisture, and an absorbent (5) of the target gas is arranged inside the cover (1) outside the selective housing (2). The cover (1) is provided with an optically readable layer (6) (an opening in this embodiment) for visually controlling when the inert gas concentration has fallen below a specified threshold.

[0009] **Example 2** An indirect indicator of inert gas leakage from the void environment of an insulating double or triple-glazed structure comprises a cover (1) in which a housing (2) having a selective layer is arranged, the layer containing a photochemical compound (3) which is guaranteed to change visually when the concentration of the inert gas decreases. The cover (1) further includes a source (4) of a medium to ensure the reaction conditions of the photochemical compound, in particular moisture, and further, an absorbent (5) of the target gas is arranged within the cover (1). The cover (1) is provided with an optically readable layer (6) (an opening in this embodiment) for visually controlling when the inert gas concentration has fallen below a specified threshold.

[0010] The photochemical compound (3) changes color in response to the partial pressure, i.e., concentration, of gases other than the inert gas, particularly oxygen or carbon dioxide, and this change is caused by oxidation-reduction reactions, fluorescence reactions, photoluminescence reactions, or other photochemical reactions, and this change in optical properties is intended to visually indicate that the inert gas concentration has fallen below a predetermined threshold. The optical change of the indicator is a change in color that is recognizable by the naked eye or an optical sensor, causing an irreversible or reversible change from one color to another at a specific oxygen concentration in the environment. In this case, it is stabilized against ultraviolet irradiation by the addition of an ultraviolet absorber or stabilizer, maintaining the color response after exposure to ultraviolet irradiation over the intended service life of the void, and exhibiting stability over a temperature cycling range of -40 to +80°C. [Industrial applicability]

[0011] This technical solution is primarily applicable to multi-layer glass units in various industries.

Claims

1. An indirect indicator for inert gas leaks, comprising an independent three-dimensional structure intended to be placed in or near the internal gas space of a double-glazed unit, the indicator comprising a cover (1) on which a housing (2) having a selective layer containing a photochemical compound (3) whose optical properties change in response to the presence of a gas other than an inert gas is disposed, the cover (1) being provided with an optically readable region (6) that can visually indicate that the inert gas concentration has fallen below a specified threshold.

2. The indicator according to claim 1, characterized in that a medium for ensuring the reaction conditions of the photochemical compound, in particular a water source (4) for ensuring the function of the photochemical compound (3), is located within the cover (1) or the housing (2).

3. The indicator according to claim 1, characterized in that the selective layer of the housing (2) is formed of a film that allows gases other than inert gases to diffuse from the voids of the double-glazed glass unit into the housing (2), and at the same time restricts the passage of a medium, particularly moisture, into the voids of the double-glazed glass unit to ensure the reaction conditions of the photochemical compound (3).

4. The indicator according to any one of claims 1 to 3, characterized in that an absorbent (5) of a gas other than an inert gas, particularly oxygen or carbon dioxide, is disposed inside the cover (1), inside the housing (2), or outside the cover (1) to suppress the indicator's response to short-term or limited supply amounts of these gases.

5. The indicator according to any one of claims 1 to 3, characterized in that the indicator shows improved stability to ultraviolet irradiation by the addition of an ultraviolet absorber or stabilizer, and maintains a color response even after being exposed to ultraviolet irradiation during the planned lifespan of the void.

6. The indicator according to any one of claims 1 to 3, characterized in that the indicator exhibits improved stability for temperature cycles in the range of -40 to +80°C.

7. The indicator according to any one of claims 1 to 3, characterized in that the presence of a gas other than an inert gas, mainly oxygen or carbon dioxide, is interpreted as an indicator of inert gas leakage.

8. The indicator according to any one of claims 1 to 3, characterized in that the indicator is designed as a disc, film, or printed mark placed in a glass void or on a spacer profile.

9. The indicator according to any one of claims 1 to 3, characterized in that the hermetically sealed environment is initially filled with an inert gas selected from argon, krypton, xenon, or nitrogen.

10. The indicator according to any one of claims 1 to 3, characterized in that an absorbent for gases other than inert gases is integrated into the desiccant medium of the spacer frame of the double-glazed unit, or is functionally connected to the desiccant medium.

11. The indicator according to any one of claims 1 to 3, characterized in that the gas other than the inert gas is, in this case, mainly oxygen or carbon dioxide.

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