Method and equipment for strengthening and / or hardening flat glass

Abstract

The invention relates to a method for strengthening and / or hardening flat glass in a system in which the flat glass is brought into contact with a liquid salt. The method is characterized in that the flat glass is transported and / or treated within the system at least partially, and in particular exclusively, in a horizontal position, wherein the two main surfaces of the flat glass have an angle to the horizontal plane in the range of -10 degrees to 10 degrees. The invention further relates to a system for strengthening and / or hardening flat glass.

Description

[0001] The invention relates to a method for solidifying and / or hardening flat glass in a system in which the flat glass is brought into contact with a liquid salt.

[0002] The invention also relates to a system for solidifying and / or hardening flat glass, in which the flat glass is brought into contact with a liquid salt.

[0003] It is known that the breaking strength of glass can be increased by a process called thermal tempering (also commonly referred to as thermal hardening or annealing). In this process, the glass workpiece to be strengthened is heated in a furnace to approximately 680 °C and then rapidly quenched to room temperature. This quenching causes the surface to solidify, and the external dimensions of the component then change only minimally. Internal stresses are created within the glass workpiece, resulting in increased breaking strength.

[0004] From DD 1579 66, a method and a device for strengthening glass products by ion exchange are known. The glass products are strengthened by alkali ion exchange between the glass surface and molten alkali salts. For strengthening, hollow glass products with downward-facing openings or hollow glass products rotated or pivoted about a horizontal axis are sprinkled with the molten salt. The salt is continuously circulated and passed through perforated plates to create a cascade of rain for the glass products arranged in several layers. A disadvantage of this method is only economically viable when using comparatively expensive specialty glass.

[0005] From DE 195 10 202 C2, a process for the production of hollow glass bodies with increased mechanical strength is known using the blow-blow and press-blow forming processes. The process is characterized by the addition of mist-like aqueous alkali metal salt solutions to the blowing compressed air in the pre- and / or final mold of the blow-blow forming process or in the final mold of the press-blow forming process.

[0006] From DE 11 2014 003 344 T5, a chemically tempered glass for flat panel displays of digital cameras, mobile phones, digital organizers, etc., is known. The chemically tempered glass has a pressure-resistant layer produced by an ion exchange process, wherein the glass has a surface roughness of 0.20 nm or higher and wherein the hydrogen concentration Y in the range to a depth X from an outermost surface of the glass satisfies the equation Y = aX + b at X = from 0.1 to 0.4 (µm). The glass is preheated to a temperature of 100°C and then immersed in molten salt.

[0007] From WO 2022 049205 A1, a flat glass sheet is known which is made from a base material that is an alkali-containing silicate glass. The flat glass sheet is characterized in that at least one surface layer is enriched in potassium and depleted in sodium and / or lithium, while an inner layer, in particular one directly adjacent to the surface layer, is neither enriched in potassium nor depleted in sodium and / or lithium, and that the flat glass sheet exhibits compressive stress down to a certain depth and tensile stress from that depth onwards, wherein the tensile stress increases with increasing depth up to a maximum tensile stress located in the inner layer, and / or wherein the tensile stress does not have a linear profile as a function of depth, and / or wherein the tensile stress does not have a constant profile as a function of depth.

[0008] The object of the present invention is to provide a method that makes it possible to efficiently and safely solidify and / or harden flat glass.

[0009] The problem is solved by a method of the type mentioned above, characterized in that the flat glass is transported and / or treated in a lying position within the system, at least partially, and in particular exclusively, wherein the two main surfaces of the flat glass have an angle to the horizontal plane in the range of -10 degrees to 10 degrees.

[0010] A further object of the present invention is to provide a system that makes it possible to efficiently and safely solidify and / or harden flat glass.

[0011] This problem is solved by a system of the type mentioned above, which is characterized in that the system has at least one station designed as a transport station and / or as a treatment station, which transports and / or treats the flat glass at least partially, in particular exclusively, in a lying position, wherein the two main surfaces of the flat glass have an angle to the horizontal plane in the range of -10 degrees to 10 degrees.

[0012] The described process for solidifying and / or hardening flat glass in a system where the flat glass is brought into contact with a liquid salt offers several advantages that improve both the efficiency of the process and the quality of the final product. The liquid salt can be, for example, molten sodium or potassium nitrate salts, or a mixture containing molten sodium or potassium nitrate salts.

[0013] This process is suitable for treating flat glass components for a wide variety of applications. For example, the treated flat glass components can be used as panes in windows, doors, and facades to enhance safety. They can also serve as protective coatings for smartphones, tablets, laptops, and other electronic devices. Solar modules represent another area of ​​application. The treated flat glass components can be used within solar modules to protect the sensitive photovoltaic cells from environmental factors such as hail, wind, and UV radiation.

[0014] In accordance with the invention, it was recognized that unprocessed flat glass, particularly flat glass directly from a flat glass production plant, is especially susceptible to damage. For example, continuous glass coming from a float line of a flat glass production plant cannot be cut directly without damage, but must first be cooled slightly before cutting. This cooling process can create stresses that may lead to further subsequent damage to the flat glass component during handling in a solidification and / or hardening plant. The cutting process sometimes results in edges with microscopic damage, which can also be the source of further subsequent damage to the flat glass component during handling in a solidification and / or hardening plant.

[0015] The method according to the invention has the distinct advantage of achieving improved process stability and uniformity because a horizontal orientation allows the flat glass to be moved during the solidification and / or hardening process largely without direct contact with fixed components of the system, or at least without the transmission of large forces via contact with fixed components of the system. In particular, the invention advantageously avoids the need to exert forces on the end faces and / or edges of the flat glass pieces by means of fixed components of the system in order to move the flat glass through the system. The near-horizontal orientation of the flat glass is particularly advantageous because it minimizes the risk of damage during transport and processing within the system, which could occur with a vertical or inclined orientation.

[0016] The horizontal orientation of the flat glass during transport and treatment within the plant ensures that the flat glass can always be supported evenly and across its entire surface, and that its structural integrity is maintained throughout the entire process.

[0017] A further advantage of the invention is that the entire process of solidification and / or hardening can take place in a continuous production line, enabling high processing capacity. The horizontal orientation of the flat glass also improves mechanical handling within the system, leading to increased efficiency.

[0018] The system can be advantageously designed to enable a continuous processing operation, in which flat glass components move uninterrupted through the various stations of the system. This means that the system is capable of processing flat glass in a continuous flow. In particular, multiple flat glass components can be within the system simultaneously, and several components can be in different phases of the production process at the same time. This significantly increases throughput, as the system operates continuously and new flat glass components can always be added to the processing while others are already being processed or have been completed.

[0019] It is particularly advantageous if the flat glass is transported without contact, at least within parts of the system. Contactless transport of the flat glass, at least within certain sections of the system, offers numerous additional benefits, both in terms of the quality of the final product and the efficiency and safety of the production process. With contactless transport, there is no direct contact between the flat glass and the fixed mechanical components of the system. This completely eliminates the risk of scratches, microcracks, chipping, or other surface damage that could result from mechanical contact. The edges of the flat glass are especially susceptible to damage from mechanical impact. Contactless transport ensures that the edges are not subjected to pressure, friction, or impacts, thus preserving the structural integrity of the glass.

[0020] In a particularly advantageous embodiment, the flat glass is transported horizontally, and especially exclusively horizontally, within the system. This avoids the risk of mechanical stresses that could arise from differences in height or lifting operations. This ensures a uniform process and reduces potential sources of error. Preferably, the flat glass is transported horizontally within the system from one treatment station to the next without any vertical movement. Alternatively or additionally, it can be advantageously provided that the flat glass is transported horizontally through at least one treatment station without any vertical movement. Eliminating vertical movement allows for precise control over the process.The consistent height facilitates the calibration and alignment of the treatment stations relative to each other, ultimately leading to higher product quality.

[0021] In a particularly advantageous design, the flat glass is supported by a fluid for at least part of its transport. This allows for transport without direct contact with fixed components of the system. This minimizes the risk of scratches, microcracks, or other damage to the glass surface or edges that could result from mechanical contact. Furthermore, this aspect can be advantageously implemented by ensuring that the fluid exerts uniform pressure across the entire underside of the flat glass, thus avoiding point loads and the associated stresses. A gentle transport mechanism based on a fluid is therefore achievable, which is particularly beneficial for thin or fragile glass. The fluid also acts as a damping agent, effectively absorbing vibrations and shocks that might occur during transport.This ensures smooth and stable movement of the flat glass through the system. Furthermore, the fluid-based transport can be advantageously integrated into a continuous production line, enabling seamless movement of the flat glass through the various process stages without interruption or manual intervention.

[0022] In particular, it can be advantageous to place the flat glass on a fluid layer, especially a liquid layer. A fluid layer, especially a liquid layer, provides the flat glass with uniform, surface-wide support. This optimally distributes the pressure on the flat glass, thus avoiding point loads. This reduces the risk of local deformations, microcracks, or other structural damage. Since the flat glass rests uniformly on the liquid layer, no additional mechanical stresses arise that could occur with an uneven or rigid support. This is particularly important for handling large or thin panes of glass, which are susceptible to stress.

[0023] The fluid layer, or more specifically the liquid layer, also acts as a kind of sliding bearing that supports the flat glass. This prevents contact with solid surfaces of the system and enables low-friction transport. This also reduces the risk of damage to the glass surface or edges. The fluid layer allows the flat glass to glide smoothly during transport through at least part of the system. This results in a gentle and careful transport process, which is particularly advantageous for delicate or high-quality flat glass.

[0024] The use of a fluid layer, in particular a liquid layer, can be advantageously integrated into various process steps, increasing the versatility of the production plant and reducing the complexity of flat glass transport within the plant.

[0025] In a particularly advantageous design, the fluid is formed from the liquid salt. This offers several benefits, especially the possibility of the liquid salt serving a dual purpose. Since the liquid salt acts as both the support medium and the treatment medium for the flat glass, the transport of the flat glass and its solidification and / or hardening can be carried out in just a few steps. This saves time and simplifies the entire process, as no separate media or transport mechanisms are required. Because the liquid salt functions as both the support medium and the treatment medium, the technical complexity of the system can be kept to a minimum.

[0026] Because the liquid salt directly supports and simultaneously treats the flat glass, heat can be efficiently and directly drawn away from the glass to achieve initial shock cooling. This approach allows for precise temperature control and uniform heat distribution, which is particularly crucial for the flat glass manufacturing process.

[0027] Preferably, the liquid salt is kept at a constant temperature, which creates a stable and controlled treatment process.

[0028] Particularly with regard to a potentially advantageous cleaning station within the system, which removes any remaining salt adhering to the flat glass after the solidification and / or hardening process, the fluid can consist of water or a cleaning solution. Using water or a cleaning solution as a carrier medium simplifies the production process by combining the transport and cleaning steps. The water or cleaning solution provides a gentle contact surface for the glass, preventing mechanical damage such as scratches or microcracks. Simultaneously, the water or cleaning solution ensures that the glass is not damaged during cleaning, as no hard surfaces or abrasive materials are involved.

[0029] Alternatively or additionally, it can be advantageous for the fluid to be a gas, particularly air. If the flat glass is carried on an air cushion or another gaseous medium, it is transported without contact. This minimizes the risk of scratches, cracks, or other mechanical damage that could result from contact with solid parts of the system.

[0030] A particularly advantageous design involves transporting the flat glass without contact across the flat top surface of a perforated plate, through whose openings the fluid flows, preferably continuously, onto the top surface. The fluid, which flows, ideally uniformly, through the openings of the perforated plate, provides consistent support across the entire underside of the flat glass. This ensures stable transport without vibrations or uneven loads.

[0031] Since the flat glass floats on a cushion of air or liquid above the perforated plate, it does not come into direct contact with the plate. This prevents scratches, cracks, and other mechanical damage that could result from contact. Furthermore, the fluid can advantageously serve a dual purpose, for example, by being the liquid salt required for the solidification and / or hardening process, or by being a cleaning fluid.

[0032] In a particularly advantageous embodiment, a flow of the fluid supporting the flat glass is generated. This can be achieved by designing the openings as nozzles that direct the fluid in a predetermined direction. In particular, the openings of the perforated plate through which the fluid flows can be designed as nozzles that impart a horizontal flow component to the outgoing fluid. This can, for example, cause the flat glass to move in a transport direction, preferably horizontal, by generating a fluid flow in that direction. The flowing fluid transfers some of its kinetic energy to the flat glass it supports. To decelerate the flat glass, a fluid flow opposite to the transport direction can be generated.

[0033] The top surface of the perforated plate preferably has an angle to the horizontal plane in the range of -10 to 10 degrees. In particular, it can be advantageously provided that the angle of the top surface of the perforated plate to the horizontal plane is adjustable in the range of -10 degrees to 10 degrees.

[0034] In a particularly advantageous design, the perforated plate is inclined relative to the horizontal plane in order to set the flat glass in motion or to slow it down.

[0035] The ability to tilt the perforated plate relative to the horizontal plane to accelerate or decelerate the flat glass offers significant advantages for controlling the movement of the flat glass components within the system. This flexibility enables precise and gentle handling of the glass and contributes to the efficiency and safety of the entire production process. For example, controlled acceleration of the flat glass is possible, whereby the flat glass is gently set in motion by gravity through a targeted tilt of the perforated plate relative to the horizontal plane. This allows for a controlled start of transport without the need for mechanical drive systems acting directly on the flat glass. The glass is transported solely by the tilt of the perforated plate or by the tilt of the perforated plate in combination with the fluid flow mentioned above.

[0036] To slow down the movement of the flat glass, it can be advantageous to temporarily tilt the perforated plate in the opposite direction. By tilting the perforated plate relative to the horizontal plane, the movement of the flat glass can be decelerated gently and in a controlled manner. This prevents a sudden stop that could lead to cracks, breaks, or other damage to the glass. The gentle deceleration still allows the flat glass to be precisely positioned at a desired location, for example, for a subsequent processing step or for transfer to another transport system within the plant.

[0037] The speed of transporting the flat glass can be precisely controlled by adjusting the tilt of the perforated plate. A steeper tilt results in faster movement, while a shallower tilt slows the glass down. This allows for flexible adjustment of the transport speed to meet varying process requirements. The ability to precisely control the glass's movement enables seamless transfer from one processing station to the next without interruptions or delays.

[0038] In an advantageous embodiment, a basin is provided in which at least part of the fluid is arranged. The basin can advantageously be designed as an overflow basin, which makes it possible to slide the flat glass horizontally onto the surface of the overflowing fluid. In particular, the basin can be an immersion basin filled with liquid salt, into which the flat glass is immersed for a solidification and / or hardening process for a treatment period. The treatment period can advantageously be in the range of 5 minutes to 300 minutes, and particularly in the range of 15 minutes to 45 minutes.

[0039] For example, it may be advantageous to have a rack that can be lowered into the immersion tank and has at least one receptacle for the flat glass, into which the flat glass is inserted, in particular pushed in horizontally, before the rack together with the flat glass is lowered vertically into the immersion tank.

[0040] The rack can advantageously have several horizontally oriented, stacked receptacles, each for one (or several) flat glass pieces. The continuous feeding of the flat glass pieces into this rack can be accomplished, for example, by first positioning the empty rack relative to the salt surface such that the lowest receptacle of the rack is at the level of the incoming flat glass pieces. A first flat glass piece is then inserted horizontally into the lowest receptacle.

[0041] After inserting the first piece of flat glass into the lowest slot of the rack, the rack is lowered slightly so that the lowest slot, along with the first piece of flat glass, is immersed in the salt bath. A second piece of flat glass is then inserted horizontally into the second-lowest slot of the rack, and the rack is lowered again so that the second-lowest slot, along with the second piece of flat glass, is immersed in the salt bath. This process is repeated until the rack is completely filled and immersed in the salt bath.

[0042] After a predetermined or predetermined treatment period in the salt bath, the rack is gradually pulled upwards out of the salt bath, with the flat glass parts being individually and successively removed horizontally from the holders and transported further. The flat glass parts can be supported by the surface of the liquid salt during removal.

[0043] With this procedure, the dwell time of the first flat glass part in the salt bath (due to this first-in-last-out principle) is indeed somewhat longer than the dwell time of the last flat glass part inserted into the rack, but this is not relevant because the processes of loading and immersing the rack and emerging from the salt bath are short in relation to the average dwell time of the flat glass parts in the salt bath.

[0044] Particularly with regard to continuous production, the system can advantageously (and according to an independent inventive concept, which can be implemented in combination with at least one of the other features described in this application, but which can also be implemented independently of the other features described in this application) include several racks, which can, for example, be arranged in a carousel. As soon as a rack is completely filled and immersed, the rack that has just been filled and immersed is removed from the filling position (preferably horizontally), while remaining within the salt bath, so that the next rack can be positioned in the filling position and filled and immersed as described above.This invention solves the problem of transferring continuously arriving flat glass parts into a salt bath where they must remain for a predetermined time, without having to make the tank spatially long enough to correspond to the predetermined time for passage through the salt bath. Therefore, it is instead provided that the continuously arriving flat glass parts are temporarily arranged in racks for the immersion process, which are immersed in a recirculating process.

[0045] To ensure the safe transfer of flat glass parts, for example from a transport table with a perforated plate into the rack, it is advantageous to design the basin as an overflow basin, with the level of the overflowing salt being at the same level as the surface of the fluid layer on the transport table. In such a design, the flat glass parts can be transferred, as it were, from surface to surface. This procedure can advantageously include positioning the rack so that part of the next compartment to be filled is already immersed in the salt bath, allowing the next flat glass part to "float" on the surface of the salt into the compartment.

[0046] Since salt always adheres to the flat glass parts removed from the basin, salt is continuously discharged from the basin, which would lead to a drop in the surface level. For this reason, it is advantageous (and according to an independent inventive concept, which can be implemented in combination with at least one of the other features described in this application, but which can also be implemented independently of the other features described in this application) to provide a control device that keeps the surface level of the liquid salt in the basin constant; preferably at the transport level of the station immediately upstream of the basin and / or the station immediately downstream of the basin in the system.For example, this can be achieved by using a control device to transfer salt from a storage container, such as a collection tray, into the basin to maintain a constant surface level of the liquid salt. A particularly advantageous design combines the control of the liquid salt surface level with continuous salt regeneration, in which a regeneration material is introduced into the basin, and / or continuous salt exchange.

[0047] In a particularly advantageous design, the flat glass is transported for at least part of its journey using a levitation transport device incorporating an ultrasonic generator and / or on an ultrasonic air bearing. Because the flat glass is suspended by ultrasonic waves, the transport is completely contactless. This prevents any physical contact with solid components, thus avoiding scratches, cracks, or other mechanical damage.

[0048] It can be advantageously provided that the flat glass is moved along a transport path by controlling the frequency and / or intensity of the ultrasonic waves and / or a sound wave pattern. In particular, a control device can control the frequency and / or intensity of the ultrasonic waves and / or a sound wave pattern such that the flat glass is moved along a transport path. The movement of the flat glass can be controlled very precisely by controlling the frequency, intensity, and pattern of the ultrasonic waves. This high precision makes it possible to move the glass exactly along a desired transport path, which increases process accuracy and enables precise positioning of the glass.

[0049] Alternatively or additionally to control by ultrasonic waves, the levitation transport device or the ultrasonic air bearing can be tilted to set the flat glass in motion or decelerate it using gravity. In particular, a control device can be provided that controls the tilt to set the flat glass in motion or decelerate it using gravity.

[0050] A transport station, within which the flat glass is transported by means of a levitation transport device incorporating an ultrasonic generator and / or on an ultrasonic air bearing, can advantageously be the first station within the system or at least part of the first station of the system. In particular, it can be advantageously provided that this transport station receives the flat glass from an upstream flat glass production plant. The transport station can, for example, be part of a receiving station designed to receive the flat glass, especially in a flat state, from a flat glass production plant.

[0051] During the transport of the flat glass by means of a levitation transport device which has an ultrasonic generator, and / or on an ultrasonic air bearing, heating to the initial temperature required for the hardening / solidification process can advantageously take place.

[0052] Heating can be advantageously achieved, for example, by microwave irradiation and / or by transport through a tempering oven. More generally, the system can include a heating device designed to heat the flat glass to an initial temperature required for the hardening / solidification process.

[0053] It can be particularly advantageous to provide that the flat glass within the system is sprinkled with liquid salt from above, in addition to contact with liquid salt from below (for example, through contact with a fluid layer consisting of the salt). In this respect, a sprinkler system can be advantageously provided which is designed to sprinkle the flat glass within the system with liquid salt from above.

[0054] A particularly advantageous embodiment of the inventive method is one in which the flat glass is produced in a flat glass production plant and immediately transferred to the plant for solidification and / or hardening. In this way, at least some of the process heat expended in the production of the flat glass can be utilized. For this purpose, the flat glass, particularly in its continuous form, is cooled only to the point where it can be cut into flat glass pieces. The still-warm flat glass pieces are then transferred, preferably directly, to the plant. Heating the transferred flat glass pieces to the initial temperature required for the hardening / solidification process is therefore less energy-intensive because intermediate cooling to room temperature is avoided.

[0055] The initial temperature can advantageously be in the range of 100 Kelvin to 300 Kelvin above the transformation temperature of the flat glass and / or in the range of 50 Kelvin below and 30 Kelvin above the Littleton point of the glass material. Particularly when processing flat glass made from alkali-alkaline earth silicate glass, the initial temperature can advantageously be in the range of 650 °C to 760 °C, and especially in the range of 680 °C to 720 °C. Similarly, the temperature of the molten salt, which can be, for example, molten sodium salt or molten potassium salt, can be in the range of 300 °C to 500 °C, and especially in the range of 390 °C to 450 °C or in the range of 400 °C to 440 °C.

[0056] The Littleton point is the temperature at which the viscosity η 10 6,6 Pa s (Pascal times second) is the unit of measurement.

[0057] In a particularly advantageous embodiment, after heating the flat glass to the initial temperature, cooling takes place, preferably in two phases, by bringing it into contact with the liquid salt.

[0058] Preferably, the heated flat glass is first subjected to shock cooling, in which the heated flat glass is brought into contact with the liquid salt. The shock cooling can advantageously last for a period of 5 to 60 seconds, particularly 30 seconds.

[0059] In a particularly advantageous embodiment, shock cooling is achieved at least partially by transporting the flat glass, heated to its initial temperature, horizontally on a fluid layer consisting of the liquid salt. This cools the underside of the flat glass. Furthermore, the shock cooling can include, preferably simultaneously, sprinkling the flat glass with the liquid salt from above. This cools the flat glass from above.

[0060] Preferably, the flat glass is cooled by means of shock cooling to a temperature in the range of 50 Kelvin to 200 Kelvin below the transformation temperature.

[0061] Preferably, after shock cooling, the flat glass is transported, particularly exclusively horizontally, to a basin containing further liquid salt. As described above, the basin can advantageously be designed as an overflow basin. Furthermore, it can be advantageously provided that the flat glass is immersed in the liquid salt of the basin for a treatment period, for example, in the manner already described above.

[0062] After the treatment period, the flat glass can be removed from the basin and transported, preferably horizontally, to at least one cleaning station.

[0063] Preferably, the cleaning station is designed to clean the flat glass of adhering salt. In particular, it can be advantageously provided that the flat glass is transported horizontally in the cleaning station on a fluid layer consisting of or containing water, or consisting of a cleaning fluid. Alternatively or additionally, it can also be provided that the flat glass in the cleaning station is sprinkled from above with a fluid consisting of or containing water, or consisting of a cleaning fluid. In this respect, the cleaning station can advantageously include a sprinkler system designed to sprinkle the flat glass in the cleaning station from above with a fluid consisting of or containing water, or consisting of a cleaning fluid.

[0064] The process is particularly advantageous when carried out with flat glass made of alkali-containing silicate glass, especially alkali-earth silicate glass, or aluminosilicate glass, or borosilicate glass. Aluminosilicate glass has the particular advantage that the process according to the invention yields particularly break-resistant flat glass parts. Borosilicate glass and alkali-earth silicate glass also have the particular advantage that the process according to the invention yields very break-resistant flat glass parts.

[0065] The invention is shown in the drawing in an exemplary and schematic manner and is described below with reference to the figures, whereby identical or similarly functioning elements are usually provided with the same reference numerals even in different embodiments. The figures show: Fig. 1 a first part of an embodiment of a system according to the invention, and Fig. 2 a second part of the embodiment of a system according to the invention.

[0066] The Fig. 1 and Fig. Figure 2 shows different parts of an embodiment of a system according to the invention.

[0067] The system includes a receiving station 1, which is designed to receive flat glass parts 2, in particular in a flat position, from a flat glass production plant (not shown). Specifically, the receiving station 1 is formed by a transport station 3, within which the flat glass 2 is transported by means of a levitation transport device, which includes an ultrasonic generator 4, and / or on an ultrasonic air bearing 5.

[0068] During transport of the flat glass 2 in the receiving station 1, it is heated to the initial temperature required for the hardening / solidification process. The system includes a heating device 6 for this purpose. In this embodiment, heating is achieved by irradiation with microwaves generated by a microwave generator 7, which may, for example, contain a magnetron. Alternatively or additionally, an oven can also be used for heating.

[0069] The transport station 3 transports the flat glass parts 2 directly to a shock cooling station 8. There, the heated flat glass 2 is subjected to shock cooling, during which it is brought into contact with the liquid salt 10. The shock cooling can advantageously last for a period of 5 to 60 seconds, particularly 30 seconds.

[0070] Shock cooling is achieved in part by transporting the flat glass 2, heated to the initial temperature, horizontally on a fluid layer 9 consisting of liquid salt 10. This cools the underside of the flat glass 2. In the shock cooling station 8, the flat glass 2 is transported without contact over the flat top surface of a perforated plate 12. Liquid salt 10 continuously flows through the openings 13 of this plate to form the fluid layer 9 that supports the flat glass 2. A collection tray 14 is provided to collect the liquid salt 10 flowing down the sides. The collected liquid salt 10 is then pumped back through the openings 13, creating a closed loop of liquid salt 10 within the shock cooling station 8.

[0071] Furthermore, the shock cooling process involves simultaneously spraying the flat glass 2 from above with liquid salt 10 via a sprinkler system 11. This cools the flat glass 2 from above. Preferably, the flat glass is cooled by shock cooling to a temperature in the range of 50 Kelvin to 200 Kelvin below the transformation temperature.

[0072] The further transport of the flat glass parts 2 within the shock cooling station 8 can be achieved by generating a fluid flow in the transport direction. For this purpose, the openings 13 of the perforated plate 12, through which the liquid salt 10 flows, can be designed as nozzles that impart a horizontal flow component to the outflowing salt 10. Alternatively or additionally, the perforated plate 12 can be inclined relative to the horizontal plane to set the flat glass 2 in motion using gravity or to decelerate it. In this respect, the perforated plate can be designed to be tiltable, so that the flat glass parts 2 slide relative to the perforated plate 12 under the force of gravity and can thus be transported.

[0073] Immediately after shock cooling, the flat glass parts 2 have already undergone a hardening process, so that contact with solid components, such as a Rack 15, is largely safe.

[0074] The shock cooling station 8 transports the flat glass parts 2 horizontally and flat directly to a submersion station 16, which has a basin 17 designed as an overflow basin and several racks 15, each of which has receptacles 18 for the flat glass parts 2.

[0075] Basin 17 contains liquid salt 10. A further collection tray 19 is provided to catch any overflowing liquid salt 10. Because basin 17 is designed as an overflow basin, it is possible to slide the flat glass 2 horizontally onto the surface of the overflowing liquid salt 10, so that the flat glass is supported by the liquid salt 10.

[0076] Each rack 15 has several horizontally oriented, stacked receptacles 18, each for a flat glass part. The flat glass parts 2 are continuously fed into the rack 15 by first positioning the empty rack 15 relative to the surface of the liquid salt 10 such that the lowest receptacle 18 is at the same level as the flat glass parts 2 coming from the shock cooling station 8. A first flat glass part 20 is then inserted horizontally into the lowest receptacle 18.

[0077] After inserting the first flat glass piece 20 into the lowest receptacle 18 of the rack 15, the rack 15 is lowered until the lowest receptacle 18, along with the first flat glass piece 20, is completely immersed in the liquid salt 10. A second flat glass piece 21 is then inserted horizontally into the second-lowest receptacle 18 of the rack 15, and the rack 15 is lowered a further distance so that the second-lowest receptacle 18, along with the second flat glass piece 21, is immersed in the liquid salt 10 bath. This process is repeated until the rack 15 is completely filled and immersed.

[0078] After a treatment period, the rack 15 is gradually pulled upwards out of the liquid salt 10, whereby the flat glass parts 2 are individually removed horizontally one after the other from the receptacles 18 and transported further, which in Fig.Figure 2 shows that the treatment period can advantageously range from 5 minutes to 300 minutes, particularly from 15 minutes to 45 minutes.

[0079] To achieve continuous production, there are several racks 15, which can be arranged in a carousel, for example, but this is not shown in the schematic figures.

[0080] Immediately after the immersion station 16, the flat glass parts 2 reach a cooling station 22. In the cooling station 22, the flat glass parts 2 are cooled to room temperature, for example in an air stream.

[0081] The cooling station 22 transports the flat glass parts 2 to a first cleaning station 23, where a pre-wash takes place. This pre-wash removes any remaining salt residue.

[0082] The pre-washing is partially carried out by transporting the flat glass 2 horizontally on a fluid layer 24 consisting of a cleaning fluid 25. This cleans the underside of the flat glass 2. In the first cleaning station 23, the flat glass 2 is transported without contact over the flat top surface of a second perforated plate 26, through whose openings 27 cleaning fluid 25 continuously flows onto the top surface to form the fluid layer 24 that supports the flat glass 2. A second collection tray 28 is provided to collect the cleaning fluid 25 flowing down the sides. The collected cleaning fluid 25 is pumped back through the openings 27, thus creating a closed loop of cleaning fluid 25 within the first cleaning station 23.

[0083] Furthermore, the first cleaning station 23 includes the simultaneous application of cleaning fluid 25 to the flat glass 2 from above by means of a second spray system 29. This cleans the flat glass 2 from above.

[0084] The further transport of the flat glass parts 2 within the cleaning station 23 can be achieved by generating a flow of the cleaning fluid 25 in the transport direction. For this purpose, the openings 27 of the second perforated plate 26, through which the cleaning fluid 25 flows, can be designed as nozzles that impart a horizontal flow component to the outflowing cleaning fluid 25. Alternatively or additionally, the second perforated plate 26 can be inclined relative to the horizontal plane to set the flat glass 2 in motion using gravity or to decelerate it. In this respect, the perforated plate can be designed to be tiltable so that the flat glass parts 2 slide relative to the second perforated plate 26 under the force of gravity and can thus be transported.

[0085] The first cleaning station 23 transports the flat glass parts 2 to a second cleaning station 30, where further cleaning takes place.

[0086] The second cleaning station 30 is constructed in the same way as the first cleaning station 23, except that water 32 is used in the second cleaning station 30 instead of the cleaning fluid 25.

[0087] Further cleaning takes place in the second cleaning station 30, in part by transporting the flat glass 2 horizontally on a fluid layer 31 consisting of water 32. This cleans the underside of the flat glass 2. In the second cleaning station 30, the flat glass 2 is transported without contact over the flat top surface of a third perforated plate 33, through whose openings 34 water 32 continuously flows onto the top surface to form the fluid layer 31 that supports the flat glass 2. A third collection tray 35 is provided to collect the water 32 flowing down the sides. The collected water 32 is pumped back through the openings 34, thus creating a water circulation loop within the second cleaning station 23.

[0088] Furthermore, the second cleaning station 30 includes the simultaneous application of water 32 to the flat glass 2 from above by means of a third spray system 36. This cleans the flat glass 2 from above. Reference symbol list: 1 Acceptance station 2 flat glass parts 3 Transport stations 4 ultrasound generators 5 ultrasonic air bearings 6 Heating device 7 microwave generators 8 shock cooling stations 9 Fluid layer 10 liquid salt 11 Irrigation system 12-hole plate 13 openings 14 drip tray 15 Rack 16 diving stations 17 basins 18 recording 19 more drip trays 20 first flat glass part 21 second flat glass part 22 Cooling station 23 first cleaning station 24 Fluid layer 25 Cleaning fluid 26 second perforated plate 27 openings 28 second drip tray 29 second irrigation system 30 second cleaning station 31 Fluid layer 32 Water 33 third perforated plate 34 openings 35 third drip tray 36 third irrigation system QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 195 10 202 C2

[0005] WO 2022 049205 A1

[0007]

Claims

[1] Method for strengthening and / or hardening flat glass (2) in a system in which the flat glass (2) is brought into contact with a liquid salt (10), characterized by that the flat glass (2) is transported and / or treated within the plant at least partially, in particular exclusively, in a lying position, wherein the two main surfaces of the flat glass (2) have an angle to the horizontal plane in the range of -10 degrees to 10 degrees. [2] Method according to claim 1, characterized by , that a. the flat glass (2) is transported within the system without contact, and / or that b. the flat glass (2) is transported horizontally, in particular exclusively horizontally, within the plant, and / or that c. the flat glass (2) is transported horizontally within the system without vertical movement from one treatment station of the system to the next treatment station of the system, and / or that d. the flat glass (2) is transported horizontally and without vertical movement through at least one treatment station of the plant. [3] Method according to claim 1 or 2, characterized by , that the flat glass (2) is supported by a fluid during at least part of its transport. [4] Method according to claim 3, characterized by , that the method has at least one of the following features a to o: a. the flat glass (2) is placed on a fluid layer (9, 24, 31), in particular a liquid layer, b. the fluid is formed from the liquid salt (10), c. the fluid is made up of water (32), d. the fluid is formed from a gas, in particular from air, e. the flat glass (2) is transported over the flat top surface of a perforated plate (12, 26 33), through whose openings (13, 27 34) the fluid flows, in particular continuously, onto the top surface. f. a flow of the fluid is generated, in particular in a transport direction or against a transport direction, g. the flat glass (2) is transported in the direction of transport by the flow of the fluid, h. the top of the perforated plate (12, 26 33) has an angle to the horizontal plane in the range of -10 to 10 degrees, i. the angle of the top of the perforated plate (12, 26 33) to the horizontal plane in the range of -10 degrees to 10 degrees is adjustable, j. the perforated plate (12, 26 33) is inclined relative to the horizontal plane in order to set the flat glass (2) in motion, k. the perforated plate (12, 26 33) is inclined relative to the horizontal plane in order to slow down a movement of the flat glass (2), l. at least part of the fluid is arranged in a basin (17), m. the basin (17) is designed as an overflow basin, n. the flat glass (2) is moved horizontally on the surface of the overflowing fluid, o. the flat glass (2) is inserted into a receptacle (18) of a rack (15), which is then lowered vertically into the basin (17). [5] Method according to any one of claims 1 to 4, characterized by , that a. the flat glass (2) is transported for at least part of its transport by means of a levitation transport device which has an ultrasonic generator (4) and / or on an ultrasonic air bearing (5), and / or that b. the flat glass (2) is moved along a transport path by controlling the frequency and / or intensity of the ultrasound waves and / or a sound wave pattern, and / or that c. the flat glass (2) is moved by tilting the levitation transport device or the ultrasonic air bearing (5). [6] Method according to any one of claims 1 to 5, characterized by, that the flat glass (2) inside the system is sprinkled from above with the liquid salt (10). [7] Method according to any one of claims 1 to 6, characterized by , that the flat glass (2) is produced in a flat glass production plant and is immediately afterwards transferred to the plant for solidifying and / or hardening. [8] Method according to claim 7, characterized by , that the method has at least one of the following features 1 to r: a. the flat glass (2) brought to the plant is heated to an initial temperature required for the hardening / solidification process, b. the initial temperature is in a range of 100 Kelvin to 200 Kelvin above the transformation temperature of the flat glass (2), c. the initial temperature is in a range of 50 Kelvin below and 30 Kelvin above the Littleton point of the glass material, d. the heating is carried out by irradiating the flat glass (2) with microwaves, e. the heating is done using an oven, f. the flat glass (2) is transported during heating, in particular by means of a levitation transport device which has an ultrasonic generator (4) and / or on an ultrasonic air bearing (5), g. the heated flat glass (2) is subjected to shock cooling, in which the heated flat glass (2) is brought into contact with the liquid salt (10), h. the shock cooling lasts for a shock cooling period in the range of 5 seconds to 60 seconds, particularly 30 seconds, i. the shock cooling is carried out at least partially by transporting the flat glass (2) horizontally on a fluid layer (9) consisting of the liquid salt (10), j. the shock cooling involves sprinkling the liquid salt (10) from above onto the flat glass (2), k. the flat glass (2) is cooled by means of shock cooling to a temperature in the range of 50 Kelvin to 200 Kelvin below the transformation temperature, I. The flat glass (2) is transported after shock cooling, in particular exclusively horizontally, to a basin (17) which contains a part of the liquid salt (10), m. the basin (17) is designed as an overflow basin and the flat glass (2) is moved horizontally onto the surface of the overflowing liquid salt (10), n. the flat glass (2) is immersed in the liquid salt (10), in particular in a rack (15), for a treatment period, o. the flat glass (2) is removed from the basin (17) after the treatment period and transported horizontally to at least one cleaning station, p. the treatment period ranges from 5 minutes to 300 minutes, particularly from 15 minutes to 45 minutes, q. the flat glass (2) is transported horizontally in the cleaning station (23, 30) on a fluid layer (31) which consists of or contains water (32) or consists of a cleaning fluid (25), r. the flat glass (2) is sprinkled from above in the cleaning station (23, 30) with a fluid which consists of water (32) or which contains water (32) or which consists of a cleaning fluid (25). [9] Method according to any one of claims 1 to 8, characterized by , that the flat glass (2) consists of an alkali-containing silicate glass, in particular an alkali-alkaline earth silicate glass, or an aluminosilicate glass, or a borosilicate glass. [10] Apparatus for carrying out a method according to one of claims 1 to 9 or apparatus for solidifying and / or hardening flat glass (2) in which the flat glass (2) is brought into contact with a liquid salt (10), characterized by, that the plant has at least one station designed as a transport station and / or as a treatment station, which transports and / or treats the flat glass (2) at least partially, in particular exclusively, in a lying position, wherein the two main surfaces of the flat glass (2) have an angle to the horizontal plane in the range of -10 degrees to 10 degrees. [11] Plant according to claim 10, characterized by that the station transports the flat glass (2) horizontally within the system, in particular exclusively horizontally. [12] Plant according to claim 10 or 11, characterized by , that the plant has at least one of the following characteristics a to m: a. the flat glass (2) is carried by a fluid during at least part of its transport, b. the station has a fluid layer (9, 24, 31), in particular a liquid layer, onto which the flat glass (2) can be placed, c. the fluid is formed from the liquid salt (10), d. the fluid is formed from water (32), e. the fluid is formed from a gas, especially air, f. the flat glass (2) is transported over the flat top surface of a perforated plate (12, 26, 33), through whose openings, in particular continuously, the fluid flows onto the top surface, g. the fluid exhibits a flow in a transport direction on the upper surface, h. the top of the perforated plate (12, 26, 33) has an angle to the horizontal plane in the range of -10 to 10 degrees, i. the angle of the top of the perforated plate (12, 26, 33) to the horizontal plane is adjustable in the range of -10 degrees to 10 degrees, j. at least part of the fluid is arranged in a basin (17), k. at least part of the fluid is arranged in a basin (17), the basin (17) being designed as an overflow basin, I. The station moves the flat glass (2) horizontally on the surface of the overflowing fluid, m. a rack (5) with at least one receptacle (18) for the flat glass (2), in particular with several receptacles (18) for at least one flat glass (2) each, is provided, which can be lowered into the basin (17). [13] Plant according to any one of claims 10 to 12, characterized by , that a. the system includes a levitation transport device comprising an ultrasonic generator (4) and / or an ultrasonic air bearing (5), and / or that b. a control device controls the frequency and / or intensity of the ultrasonic waves and / or a sound wave pattern such that the flat glass (2) is moved along a transport path, and / or that c. the levitation transport device and / or the ultrasonic air bearing is mounted in a tiltable manner in order to move the flat glass (2) by tilting the levitation transport device or the ultrasonic air bearing (5). [14] Plant according to any one of claims 10 to 13, characterized by that the plant has at least one of the following characteristics a to h: a. a sprinkler system (11) is provided which is designed to sprinkle the flat glass (2) inside the system from above with the liquid salt (10), b. the plant has a receiving station (1) which is designed to receive the flat glass (2), in particular lying flat, from a flat glass production plant, c. the system includes a heating device (6) designed to heat the flat glass (2) to an initial temperature required for the hardening / solidification process, d. the heating device (6) has a microwave generator (7), e. the heating device (6) includes an oven, f. a cleaning station (23, 30) is provided which is designed to clean the flat glass (2) of adhering salt (10), g. the cleaning station (23, 30) is designed to transport the flat glass (2) horizontally on a fluid layer (32) which consists of or contains water (32) or consists of a cleaning fluid (25), h. the cleaning station (23, 30) has a sprinkler system designed to sprinkle the flat glass (2) in the cleaning station (23, 30) from above with a fluid which consists of water (32) or which contains water (32) or which consists of a cleaning fluid (25).

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