Glass Tempering Furnace and Glass Tempering Method

Abstract

A glass strengthening furnace and a glass strengthening method, comprising a preheating corrugated furnace body, a heating corrugated furnace body, and a soaking corrugated furnace body, the preheating corrugated furnace body is divided into a plurality of stages along the direction of glass travel, each stage is provided with a smoke intake port and a smoke injection joint, the preheating corrugated furnace body is configured to suck in smoke from the preheating stage through the smoke intake port, the smoke injection joint is configured to send the sucked smoke to the furnace body, the heating corrugated furnace body is provided with a plurality of infrared combustors, the infrared combustors are porous media combustors, and the soaking corrugated furnace body is provided with a plurality of air ducts, which are configured to generate horizontal and parallel air flows on the upper and lower surfaces of the glass.

Description

Technical Field

[0001] This application claims the priority of a Chinese patent application with an application date of November 1, 2022 and an application number of 202211358216.6, a Chinese patent application with an application date of November 1, 2022 and an application number of 202222929439.5, and a Chinese patent application with an application date of September 4, 2023 and an application number of 202322399577.1. All the contents of the said application are incorporated herein by reference.

[0002] This application relates to the field of glass strengthening, for example, to a glass strengthening furnace and a glass strengthening method.

Background Art

[0003] Glass, as a transparent or translucent amorphous material, exhibits unique performance in the heat transfer process. Glass has a short-range order and long-range disordered structure. Glass is transparent or translucent to visible light and infrared light. When receiving external heat, high-frequency electromagnetic radiation energy is generated inside, and such a heat transfer process is called photon heat conduction. Photon heat conduction of transparent glass at room temperature accounts for about 10% of the total heat transfer. As the temperature rises, the effect of photon heat conduction increases, and volume radiation occurs inside the glass.

[0004] Ordinary transparent glass has a high emissivity and can well absorb thermal radiation energy. By coating a thin film with low radiation performance on the surface of ordinary glass, Low-E glass is made. The most prominent characteristic of Low-E glass is that it has a high reflectivity to far-infrared radiation, a low reflectivity to near-infrared radiation, and a high transmittance to visible light. This means that after Low-E glass is used in a building, the visible light part in sunlight can pass through and play a role in lighting, while most of the infrared radiation that can generate a thermal effect is blocked outside the window. Due to the surface modification of Low-E glass, many technical problems occur in the strengthening heating process.

[0005] Compared with ordinary glass, tempered glass belongs to safety glass. Tempered glass is actually glass with prestress applied in advance. In order to increase the strength of the glass, usually, chemical or physical methods are used to form compressive stress on the surface of the glass. When the glass receives external force, the surface stress is first offset, thereby increasing the load-bearing capacity and enhancing the wind pressure resistance, cold resistance, heat resistance, impact resistance, etc. of the glass itself.

[0006] The strengthening of glass is divided into "physical strengthening" and "chemical strengthening".

[0007] In physical strengthening, when ordinary flat glass is heated in a heating furnace to a temperature close to the softening point of the glass (600 °C), the internal stress is removed by its own strain. After the glass is taken out of the heating furnace, high-pressure cold air is blown onto both sides of the glass through a multi-nozzle, and the glass is quickly and uniformly cooled to room temperature to produce tempered glass.

[0008] Chemical strengthening increases the strength of the glass by changing the chemical composition of the glass surface, and generally applies the ion exchange method for strengthening. The method is to immerse silicate glass containing alkali metal ions into molten lithium (Li+) salt, and exchange Na+ or K+ ions on the glass surface layer with Li+ ions to form a Li+ ion exchange layer on the surface. Since the expansion coefficient of Li+ is smaller than that of Na+ and K+ ions, during the cooling process, the outer layer shrinks less and the inner layer shrinks more. After being cooled to room temperature, the glass is also in a state where the inner layer is pulled and the outer layer is under pressure, and its effect is similar to that of physical strengthening of the glass.

[0009] What is described in this application is the equipment related to physical strengthening - the strengthening heating furnace.

[0010] From the perspective of heat transfer, the heat transfer process related to the heating process of the glass in the strengthening furnace includes "radiation heat transfer", "convection heat transfer", and "heat conduction".

[0011] Regarding radiative heat transfer, radiation exists everywhere. After a cold glass sheet enters the heating furnace of a glass toughening furnace, various heating elements, furnace wall insulation materials, and ceramic rollers all emit radiant heat to heat the glass. Waves have two forms, "absorption + transmission", with respect to the object to be heated, and can heat the object just by absorption. From the spectral curve of the glass, due to component reasons, it is not a single straight line on the infrared transmission curve, but is expressed in the form of "peaks and valleys". Correspondingly, the "valleys" are the wavelength ranges that the glass can absorb, and there is more than one absorbable wavelength.

[0012] Figure 12 is only the infrared transmission curve of the glass according to an embodiment, and the curves of different types of glass are different. This is because in the process of strengthening and heating the glass, the wavelength of the wave radiated from the heat source to the outside should be a wave with a "wide range", and it is required to cover the absorption wavelengths corresponding to different types of glass as much as possible. In fact, that is, it is required that the temperature of the heat source can be high and can also be low (compared with the resistance wire).

[0013] Regarding convective heat transfer, in the process of producing tempered glass, there are the following several convective heat transfer methods.

[0014] 1. Regarding natural convection, when there is a temperature difference in the furnace, the air flows naturally. When the cold glass enters the heating furnace, there is natural convection heating on the lower surface of the glass, and the upper surface of the glass forms an air barrier with the cold air. Without forced convection, the influence of natural convection heating is small. The influence of natural convection on the four sides of the block-shaped flat glass is significant, generally resulting in the "hot side" of the glass, which causes the temperature of the edge of the glass to be too high and affects the optical imaging quality of the glass.

[0015] 2. Regarding forced convection with a heat balance tube attached, generally, there is a heat balance tube near the heating element in the heating furnace. The compressed air in the trachea is heated to hot air and directly blows onto the upper and lower surfaces of the glass. The heat balance gas heats the glass by forced convection while also making the temperature in the heating furnace uniform. However, when the glass is in a high-temperature softening state, an air current with a certain speed and pressure forms "patterns" on the surface of the softening glass, which is also a drawback of such forced convection.

[0016] 3. Regarding forced convection as the main heating method, both gas heating furnaces and air cushion type heating furnaces use forced convection as one of the main heating methods. As the market application capable of strengthening Low-E glass rapidly spreads, forced convection heating furnaces using high-temperature fans or compressed air have also developed. By adopting the forced convection heating method, the heating time of the glass can be shortened, the production efficiency can be increased, the temperature of the glass can be made more uniform, and the quality of the product can be improved.

[0017] Regarding heat conduction, the upper surface of the glass does not contact the element in the furnace, and only the lower surface contacts the ceramic roller. The ceramic roller is mainly made of quartz and is manufactured by adding auxiliary materials. Its thermal expansion coefficient is almost 0 and its thermal conductivity is also low. The contact area between the ceramic roller and the glass is small (theoretically line contact). Therefore, heat conduction is not the main method in the overall heat transfer process, and the heat absorbed by the glass in the heating furnace from heat conduction is less than 10%. However, at the initial stage when the cold-state glass enters the furnace, the lower surface of the cold-state glass contacts the high-temperature ceramic roller, which may cause the glass to warp or bulge upwards, and attention needs to be paid to this point.

[0018] In the related art, when heating glass in a radiation type reheating furnace in the industry, the heat source comes from the heating elements at the furnace top and the furnace bottom. The heating elements are usually nickel-chromium resistance wires. There are two types of installation forms for the heating elements. The first is installed in a metal tube and radiates heat in the form of a radiation tube. The second is embedded in a heat-resistant ceramic tube, and the resistance wire directly radiates heat into the furnace. The glass is usually placed flat on a transmission roller made mainly of heat-resistant ceramics, and is fed into the furnace by the rotation of the roller. To be able to strengthen large-sized flat glass, the heating elements in the furnace are generally arranged as full as possible at the furnace top and the furnace bottom. When the glass is fed into the furnace at room temperature, it receives radiant heat transfer from the heating elements and heat conduction to the contacting glass by the transmission roller. The furnace temperature is generally about 700 °C. Since the temperature of the transmission roller is high, the glass obtains a large amount of heat by heat conduction, whereby the temperature of the lower surface of the glass becomes higher than that of the upper surface, resulting in a non-uniform temperature distribution in the thickness direction of the glass plate. The glass bends and the edges warp upward. At this time, gravity concentrates on the central part of the glass plate, and roller marks are formed. The non-uniform heating further causes white spots to appear in the central part of the glass. When strengthening the base sheet of laminated glass, this problem becomes even more serious.

[0019] Low emissivity (Low-E) glass has a film coating on one side surface of ordinary glass. During strengthening, in order to avoid damage to the coating film layer by the roller, the coating film is sent into the strengthening furnace with the surface facing upward. Analyzing from the perspective of heat transfer, in order to ensure that the glass is heated evenly, it is required that the heat transfer rates from the upper and lower surfaces of the glass to the inside of the glass during heating are kept consistent. The heating element mainly heats the Low-E glass by radiation. When infrared radiation is projected onto an object, an obvious thermal effect occurs, and it is a main component of heat rays. The emissivity of Low-E glass is uneven, and the lower surface of the glass has a relatively high emissivity of about 0.90. After absorbing a large amount of heat, the temperature of the lower surface rises, the effective thermal conductivity increases, and the heat quantity is further transferred to the inside. On the other hand, the emissivity on the coating film side is generally 0.10 - 0.23. The coating film layer reflects a large amount of infrared radiation energy, thereby making it difficult for heat radiation to be transferred from the surface of the coating film to the inside of the glass.

[0020] In related technologies, in order to heat the surface of the glass evenly, the surface of the glass must be completely covered by a heating element. Such a surface heating method is characterized by the need to supply at least 50% of the heat quantity of the heat source to the surface of the object to be heated or the layer close to the surface. There are limitations to the heating method in related technologies. For example, when using a resistance wire of chromium-aluminum-cobalt metal wire for heating, at 1000 °C, the maximum load on the wall surface of the heater can only reach 60 kW / m 2 but the power density radiated by a full-surface black radiator at the same temperature can reach 149 kW / m 2 In the resistance wire heating in related technologies, the arrangement of the heaters is extremely dense, and such an arrangement shortens the service life of the heating element.

[0021] In the process of glass heating, in the related art, the maximum heating temperature of the nickel-chromium alloy of the electric heating heating element is 1150°C, and the maximum heating temperature of the iron-chromium alloy is 1400°C. Considering the furnace temperature and cost, in the related art, an electric heating heating element made of nickel-chromium alloy is often used. From the correspondence between the heat source temperature and the radiation wavelength, the wavelength radiated outward at a heating temperature of 1150°C is 2.04 microns. Considering the furnace temperature and the strengthening temperature of the glass, the heating temperature of the resistance wire in the electric heating strengthening furnace is less than 1150°C, usually between 800°C and 900°C, and the corresponding heat source radiation wavelength is 2.47μm - 2.7μm. Such a wavelength is actually narrow, and not all the absorption wavelengths of the glass are between 2.47μm and 2.7μm.

[0022] The related art has gradually started to use an infrared radiator to uniformly heat the transparent glass, increase the heating rate of the glass, and shorten the heating time. However, the drawback of such a method is that it cannot guarantee uniform radiation to the entire surface of the glass object, so that a projection of the intensity distribution of the infrared radiation source is formed on the surface of the glass that needs to be heated.

[0023] To solve the above problems, the glass industry has introduced the "forced convection heat exchange technology" into the strengthening furnace. Adding upper forced convection in the roller type strengthening furnace is beneficial to the symmetrical heating of the glass. Also, for Low-E glass, due to the presence of the coating film, the heating time is significantly increased. By adding forced convection, the heating time can be shortened, the temperature of the furnace chamber can be lowered, the loss of the film layer can be reduced, and it is beneficial to improve the production efficiency. There is no need to add forced convection at the lower part. Originally, in the roller type strengthening furnace, due to the inevitable heat transfer of the roller and the natural convection at the lower part, the heating at the lower part is too fast, causing the glass to warp upward and forming white fog in the middle. More importantly, when the heating in the middle is too fast and the center of the glass is heated to the strengthening temperature, the lower surface becomes too hot and too soft, resulting in bumps and roller traces on the lower surface of the glass, which is troublesome. Adding forced convection at the lower part will make this contradiction more prominent.

[0024] However, in the related art, the strengthening of glass, especially the strengthening of coated glass and Low-E glass, has problems such as the upward warping and shaking of the glass due to the too-fast increase in the temperature of the lower surface of the glass and the too-slow increase in the temperature of the upper surface of the glass at the initial stage when the glass enters the furnace, the short service life and slow heating rate due to the extremely dense arrangement of the heating elements of the electric heating strengthening furnace, and the uneven heating phenomenon and high energy consumption due to the infrared radiation heating technology introduced into the strengthening furnace still exist.

Summary of the Invention

[0025] This application proposes a glass strengthening heating furnace and a glass strengthening method that can rapidly and uniformly heat glass, and can be further applied to the strengthening heating of ordinary glass, and is particularly applicable to the strengthening requirements of coated glass and Low-E glass.

[0026] This application discloses a glass strengthening heating furnace comprising a preheating stage furnace body having a feed port provided with a total exhaust port, divided into multiple stages along the advancing direction of the glass, with a smoke suction port and a flue gas injection joint provided in each stage respectively; a heating stage furnace body provided with a plurality of infrared burners which are porous medium burners; and a soaking stage furnace body provided behind the heating stage furnace body along the advancing direction of the glass, with a plurality of air ducts provided therein configured to generate horizontal and parallel airflows on the upper and lower surfaces of the glass. The preheating stage furnace body is configured to suck the flue gas of the heating stage furnace body through the smoke suction port and send the sucked flue gas into the preheating stage furnace body through the flue gas injection joint.

[0027] This application further discloses a glass strengthening method carried out by adopting the above glass strengthening and heating furnace. The method includes laying glass flat in a single layer manually (or by an automation device) on a side material placement table and arranging products; running the glass with a transmission roller so as to enter a preheating stage furnace body and completing the preheating of the products in the preheating stage furnace body; letting the glass enter a heating stage furnace body and raising the temperature of the glass to a preset temperature of 600°C to 640°C; letting the glass enter from the heating stage furnace body into a soaking stage furnace body, and the circulating gas skim over the upper and lower surfaces of the glass to heat the glass and equalize the temperature.

Brief Description of the Drawings

[0028]

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Description of Reference Numerals

[0029] 10... Glass strengthening heating furnace, 20... Glass, 100... Preheating stage furnace body, 101... Transmission roller, 1011... First end, 1012... Second end, 102... Upper furnace body of the preheating stage, 103... Lower furnace body of the preheating stage, 120... Total smoke exhaust port, 130... Smoke suction port, 131... First smoke suction port, 132... Second smoke suction port, 133... Third smoke suction port, 134... Fourth smoke suction port, 135... Fifth smoke suction port, 136... Sixth smoke suction port, 140... Smoke injection joint, 141... First smoke injection joint, 142... Second smoke injection joint, 143... Third smoke injection joint, 144... Fourth smoke injection joint, 150... Smoke injection air knife, 151... Right air knife on the upper furnace body, 152... Left air knife on the upper furnace body, 153... Air knife air outlet, 160... Increaser, 161... Passage of the venturi tube structure, 162... Shrinkage section, 163... Gap, 164... Increaser outlet, 200···Heating section furnace body, 201···Upper furnace body of heating section, 202···Lower furnace body of heating section, 210···Infrared combustor, 2111···Cover plate, 2112···Air intake port, 2113···Heat release port, 2114···Inner cylinder body, 2115···Premixing area, 212···Cooling intervening layer, 2121···Outer cylinder body, 2122···Cooling inlet, 2123···Cooling outlet, 218···Backfire prevention area, 219···Combustion area, 213···Heat insulation material plate, 214···Porous media material layer, 2151···Thermocouple, 2152···Heat preservation material layer, 2153···Heat insulation material support layer, 2154···Bottom heat insulation panel, 2155···Pressing mechanism, 2156···Bottom panel, 2157···Reinforcing rib, 2161···Combustion air pipeline, 2162···Combustion air fan, 2163···First branch path, 2164···Second branch path, 2165···Air-fuel mixer, 2171···Cooling water tank, 2712···Hot water tank, 220···Airflow stirring device, 300···Soaking section furnace body, 310···Air duct, 311···Centrifugal fan, 3121···Air blowing section air duct, 31211···First part air duct, 31212···Second part air duct, 3122···Air suction section air duct, 313···Air outlet, 314···Air suction inlet, 320···Heater, 321···Heating part, 330···Upper furnace body of soaking section, 340···Lower furnace body of soaking section, 350···Containment chamber, 351···Bottom wall, 352···Ceiling wall, 353···Side wall, 400···Furnace body lift device.

Embodiments for Carrying out the Invention

[0030] In the description of this application, terms such as "center", "vertical direction", "horizontal direction", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial direction", "radial direction", "circumferential direction", etc. refer to the orientation or positional relationship shown in the drawings, and are only for facilitating and simplifying the description of this application, and do not indicate or imply that the mentioned devices or elements must have a specific orientation and be configured and operated in a specific orientation. Therefore, it should not be understood as limiting this application.

[0031] Also, features limited as "first" and "second" can explicitly or implicitly include one or more of such features, and are for distinguishing the description of the features, and there is no difference in order or importance. In the description of this application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0032] In addition, in the description of this application, unless there are separate clear regulations and limitations, the terms "attach", "connect", "couple" should be understood in a broad sense. For example, it may be a fixed connection, a removable connection, or an integral one, a mechanical connection, an electrical connection, a direct connection, or an indirect connection through an intermediate medium, or a communication inside two elements. A person skilled in the art can understand the specific meaning of the above terms in this application according to the specific situation.

[0033] Referring to FIGS. 1 to 11, an embodiment of this application provides a glass strengthening heating furnace 10 including a preheating stage furnace body 100, a heating stage furnace body 200, and a soaking stage furnace body 300 sequentially provided along the advancing direction of the glass 20.

[0034] In some embodiments of this application, the preheating stage furnace body 100 has a feed port, and a total smoke exhaust port 120 is provided at a location near the feed port.

[0035] In the related art, generally, the general smoke exhaust port is provided in the heating stage. However, in the present application, the smoke exhaust port in the heating stage is moved forward to reach the position of the feed port in the preheating stage, so that the smoke moves from the heating stage to the preheating stage and serves as the heat source in the preheating stage. On the other hand, the smoke exhaust port and the heating stage are separated by a certain distance to reduce the influence of smoke exhaust on the temperature field of the heating stage.

[0036] In some embodiments of the present application, along the advancing direction of the glass 20, the preheating stage furnace body 100 is divided into multiple stages, and each stage is provided with a smoke suction port 130 and a flue gas injection joint 140 respectively. The smoke suction port 130 is Heating configured to suck the smoke of the stage. The smoke from the heating stage furnace body 200 is sucked through the smoke suction port 130, and the sucked smoke is sent into the preheating stage furnace body 100 through the flue gas injection joint 140.

[0037] In the related art, for the smoke generated in the heating stage of the glass strengthening heating furnace, a smoke suction port is provided at the inlet of the furnace and connected to a chimney externally, and the "chimney effect" is utilized for discharging.

[0038] The present application introduces the preheating stage furnace body 100 in the front part of the heating stage furnace body 200 and provides the general smoke exhaust port 120 of the whole equipment at the inlet of the preheating stage. At the same time, by providing the smoke suction port 130 at each stage of the preheating stage furnace body 100 along the advancing direction of the glass 20, the smoke in the furnace can be sucked out from each smoke suction port 130 by using a fan, and the sucked smoke can be sent into the furnace through the flue gas injection joints 140 at each stage, thereby constructing an internal circulation of the smoke in the preheating stage furnace body 100. Therefore, the preset index that the pressure in the furnace is maintained at "slightly positive pressure" can be realized, and the overall flow of the smoke in the furnace can be realized to move from the heating stage furnace body 200 to the preheating stage furnace body 100.

[0039] In the actual operation process, since the smoke inlets 130 are provided at each stage of the preheating stage furnace body 100, the smoke in the furnace can be sucked out from each smoke inlet 130 by using a fan. By doing so, the pressure inside the preheating stage furnace body 100 becomes lower, and the pressure inside the heating stage furnace body 200 becomes higher than the pressure inside the preheating stage furnace body 100. The smoke in the heating stage furnace body 200 enters the preheating stage furnace body 100 under the action of differential pressure. At the same time, the smoke injection joint 140 of the preheating stage furnace body 100 sends the sucked-out smoke back into the preheating stage furnace body 100. Thereby, the overall flow of the smoke in the furnace realizes the function of moving from the heating stage furnace body 200 to the preheating stage furnace body 100 and circulating reciprocally.

[0040] By providing the preheating stage furnace body 100, while secondarily utilizing the smoke of the heating stage furnace body 200, the preheating stage furnace body 100 is divided into multiple stages, the smoke is sucked by the smoke inlets 130, and sent back by the smoke injection joint 140, realizing the stepwise temperature increase of the glass 20 in the preheating stage furnace body 100. At the same time, considering that the heat quantity of the preheating stage furnace body 100 comes from the smoke of the heating stage furnace body 200 and the glass 20, which is a cold source, continues to enter, the temperature of the transmission roller 101 of the preheating stage furnace body 100 is much lower than the temperature of the transmission roller 101 of the heating stage furnace body 200. By doing so, it is possible to preferably avoid the deformation (upward warping) and deviation caused by the excessive temperature difference between the upper and lower surfaces at the initial stage when the glass 20 enters the heating furnace due to the excessively high temperature of the transmission roller 101.

[0041] This application provides a soaking stage furnace body 300 after the heating stage furnace body 200 to further improve the non-uniformity of the surface temperature of the glass 20 in the heating stage, so as to meet the requirements of higher standard uniformity and further improve the strengthening quality of the glass 20. In particular, it is applicable to the strengthening requirements with high standard uniformity requirements for types of coated glass and Low-E glass.

[0042] In a normal glass strengthening heating furnace in the related art, it is necessary to solve the warping and shaking caused by the non-uniform heat initially received by the glass in the heating stage. The glass strengthening heating furnace 10 of the present application is completely different from the normal glass strengthening heating furnace in the related art. The preheating stage furnace body 100 is installed independently, the flue gas in the heating stage is used as a heat source, the preheating stage is installed independently, the temperature of the ceramic roller rods in the preheating stage is lowered, and the glass 20 is preheated in the form of forced convection, solving the problems of warping and shaking caused by the non-uniform heat initially received by the glass 20.

[0043] In some embodiments of the present application, the above-mentioned preheating stage furnace body 100 is divided into three stages along the advancing direction of the glass 20. The preheating stage furnace body 100 is divided into a preheating stage upper furnace body 102 and a preheating stage lower furnace body 103. The preheating stage upper furnace body 102 is provided above the transmission roller 101, and the preheating stage lower furnace body 103 is provided below the transmission roller 101.

[0044] Referring to FIGS. 2 to 3, the preheating stage furnace body 100 is divided into a total of six stages, namely, the "upper 1#" stage and the "lower 1#" stage, the "upper 2#" stage and the "lower 2#" stage, and the "upper 3#" stage and the "lower 3#" stage. In the six stages, each stage is provided with a smoke suction port 130 in the furnace body, and a fan is used to suck out the flue gas in the furnace, and then, through the smoke injection joint 140 of each stage, the sucked flue gas is sent into the furnace, thereby constructing an internal circulation of the flue gas in the preheating stage furnace body 100.

[0045] Referring to FIGS. 2 and 3, in the preheating stage furnace body 100, a first smoke suction port 131 is provided in the upper 1# stage, a second smoke suction port 132 is provided in the lower 1# stage, a third smoke suction port 133 is provided in the upper 2# stage, a fourth smoke suction port 134 is provided in the lower 2# stage, a fifth smoke suction port 135 is provided in the upper 3# stage, and a sixth smoke suction port 136 is provided in the lower 3# stage.

[0046] In one embodiment, taking the upper 1# stage as an example, the first smoking port 131 of this stage is connected to the air inlet of the smoke suction fan, sucking out the smoke in the furnace by the fan, dividing it into two parts by a pipeline, and sending each part into the first smoke injection joint 141 and the second smoke injection joint 142 of the upper 1# stage. Similarly, the second smoking port 132 provided in the lower 1# stage is connected to the air inlet of the smoke suction fan, sucking out the smoke in the furnace by the fan, dividing it into two parts by a pipeline, and sending each part into the third smoke injection joint 143 and the fourth smoke injection joint 144 of the lower 1# stage.

[0047] In some embodiments of the present application, in the preheating stage furnace body 100, along the advancing direction of the glass 20, a plurality of smoke injection air knives 150 are respectively provided on the upper and lower sides of the transmission roller 101, and the plurality of smoke injection air knives 150 on the upper and lower sides and the plurality of transmission rollers 101 are arranged offset in the height direction. The smoke injection joint 140 is configured to send the sucked smoke into the plurality of smoke injection air knives 150.

[0048] Referring to FIGS. 2 to 4, in the illustrated embodiment, a plurality of smoke injection air knives 150 are provided in all six stages of the "upper 1#" stage, "lower 1#" stage, "upper 2#" stage, "lower 2#" stage, "upper 3#" stage, and "lower 3#" stage in the preheating stage furnace body 100.

[0049] In some embodiments of the present application, the caliber of the air knife air outlet 153 of the plurality of smoke injection air knives 150 is constricted.

[0050] In some embodiments of the present application, an increaser 160 is provided in the preheating stage furnace body 100. The increaser 160 has a passage 161 with a Venturi tube structure, and the passage 161 is connected to the air knife air outlet 153 of the smoke injection air knife 150.

[0051] Referring to FIGS. 6 and 11, by providing the increaser 160 with a passage 161 of a Venturi tube structure, a Venturi effect is generated to form an "increasing" effect, and the amount of air blown onto the glass 20 can be increased. The increaser 160 installed in the present application has undergone simulation analysis of the flow field and actual experimental verification, and greatly enhances the heating effect.

[0052] In related technologies, the flue gas injection structure usually adopts the "circular hole offset arrangement type" and "slit type" flue gas injection structures. However, in the present application, a structure with an "increasing" effect is creatively developed to realize an increase in the amount of flue gas injected and further improve the heating efficiency.

[0053] Exemplarily, referring to FIGS. 5 to 6, in the illustrated embodiment, the "increasing" structure of the flue gas injection in the preheating stage furnace body 100 is as shown in FIGS. 5 and 6. In the stage of heating the empty furnace to raise the temperature, the transmission roller 101 in the furnace is in a cold state. To avoid directly injecting high-temperature flue gas onto the surface of the transmission roller 101, the flue gas injection air knife 150 is not directly blown onto the transmission roller 101 but is arranged offset and blown into the gap between the transmission rollers 101. As shown in FIGS. 5 and 6, the internal structure of the preheating stage furnace body 100 mainly consists of a transmission roller 101, an upper furnace body right air knife 151, an upper furnace body left air knife 152, and an increaser 160. The glass 20 runs from left to right by the rotation of the transmission roller 101. The fan sucks the flue gas in each stage of the furnace and sends the preheated flue gas into the flue gas injection air knife 150 through the flue gas injection joint 140 outside the furnace. The flue gas injection air knife 150 designed with a special structure contracts at the air knife air outlet 153, and one increaser 160 is attached at a location at a preset distance from the air knife air outlet 153 of each flue gas injection air knife 150. The increaser 160 forms an "increasing" effect through a special design, increases the amount of air blown onto the glass 20, and has undergone simulation analysis of the flow field and actual experimental verification. The application of the increaser 160 greatly enhances the heating effect.

[0054] In one embodiment, referring to FIG. 6, when the flue gas ejected from the flue gas injection air knife 150 passes through the contraction section 162 of the increaser 160, the flow velocity increases, forming a low-pressure area. Due to the action of the low-pressure area, the flue gas present in the preheating stage furnace body 100 is sucked into the increaser 160 from the gap 163 between the flue gas injection air knife 150 and the increaser 160. The two flue gases merge at the increaser outlet 164 and are ejected onto the heating surface of the glass 20. Thereby, in the case of the same power of the flue gas fan, a greater injection effect of the flue gas amount is realized on the heating surface of the glass 20.

[0055] In some embodiments of the present application, along the advancing direction of the glass 20, the heating stage furnace body 200 is provided behind the preheating stage furnace body 100.

[0056] In some embodiments of the present application, referring to FIGS. 7 and 8, the heating stage furnace body 200 is divided into a heating stage upper furnace body 201 and a heating stage lower furnace body 202. The heating stage upper furnace body 201 is provided above the transmission roller 101, and the heating stage lower furnace body 202 is provided below the transmission roller 101.

[0057] In some embodiments of the present application, the heating stage furnace body 200 is provided with a plurality of infrared burners 210 which are porous medium burners.

[0058] The heating stage furnace body 200 of the present application adopts a porous medium combustion technology mainly based on infrared radiation. There are three types of heat exchange methods: convection, heat conduction, and radiation, which make the temperature of the combustion area 219 uniform and maintain a gentle temperature gradient. In addition to adopting the porous medium combustion technology mainly based on infrared radiation, the heating stage furnace body 200 of the present application also constructs an infrared heating stage with a wide waveband to achieve rapid and uniform heating of the glass. Thereby, the glass strengthening heating furnace of the present application is applicable not only to the strengthening of ordinary glass but also particularly applicable to the strengthening requirements of coated glass and Low-E glass.

[0059] The porous medium combustion technology has a high volumetric heat generation rate while maintaining stable combustion. Compared with free combustion, porous medium combustion has the advantages of high combustion speed, good combustion stability, wide load adjustment range, large volumetric heat generation rate, small combustor volume, good gas adaptability, low emission of pollutants in flue gas, wide combustion limit, and the ability to burn and use gases with low calorific value, etc.

[0060] In this field, the heating furnace in the related technology is the combustion of gaseous fuel, mainly featuring free flame combustion. Such combustion requires a large space, has a large temperature gradient around the flame, and is prone to generating local high temperatures. When the temperature is higher than 1500 °C, the generation of NOx (nitrogen oxides) becomes prominent. Due to the highly toxic nature of NOx (nitrogen oxides), reducing the emission of NOx is also very important.

[0061] Compared with the conventional free flame combustion characteristics of the heating furnace in the related technology, the heating stage furnace body 200 of the present application adopts a porous medium combustor to greatly improve the combustion effect. In the combustion process, the porous medium plays a key role. The porous medium material has excellent heat transfer characteristics. The gas is forced to flow in and out, separate and merge, which enhances convection, makes the temperature distribution inside uniform, and can maintain a low temperature level. It can reduce the emission of pollutants, has a small bulk density, that is, a small thermal inertia, can quickly increase the temperature during startup, and can quickly adapt to changes in load. It has characteristics such as being able to operate in the temperature range of 800 - 1200 °C.

[0062] In some embodiments of the present application, the infrared combustor 210 of the above heating stage furnace body 200 uses a porous medium material as the main combustion component and burns gas with the porous medium material. The porous medium material of the present application selects SiC. The emissivity of the SiC material is about 0.9, which is much higher than the emissivity of general metal alloy heating materials, and the radiative heating effect is better. By adopting SiC as the porous medium material, the infrared combustor 210 of the heating stage furnace body 200 of the present application further enhances the heating effect.

[0063] The heating stage furnace body 200 of the present application adopts an infrared burner 210 with "porous medium combustion" technology as the core.

[0064] In some embodiments of the present application, inside the heating stage furnace body 200, a plurality of infrared burners 210 are arranged offset above and below the transmission roller 101 along the advancing direction of the glass 20.

[0065] Referring to FIG. 7, in the illustrated embodiment, inside the heating stage furnace body 200, each infrared burner 210 in the upper furnace body of the heating stage and each infrared burner 210 in the lower furnace body of the heating stage are offset from each other in the advancing direction of the glass 20.

[0066] By arranging a plurality of infrared burners 210 offset above and below the transmission roller 101 along the advancing direction of the glass 20 inside the heating stage furnace body 200, the heating uniformity can be improved.

[0067] In some embodiments of the present application, an air flow stirring device 220 is further provided inside the heating stage furnace body 200, and along the advancing direction of the glass 20, the air flow stirring device 220 is provided at an interval from the infrared burner 210.

[0068] The drawback of infrared radiation is that it cannot guarantee uniform radiation over the entire surface of an object, so a projection of the intensity distribution of the infrared radiation source is formed on the surface that needs to be heated. Therefore, in the present application, the air flow stirring device 220 is provided in the heating stage furnace body 200 to cooperate with the infrared burner 210, and the air flow stirring device 220 and the infrared burner 210 are provided at an interval. The air flow stirring device 220 can stir the flue gas in the furnace, avoiding the local concentration of high-temperature flue gas in the furnace and the uneven furnace temperature. On the other hand, the stirred flue gas flows over the surface of the glass 20 at a preset speed, increasing the convective heat transfer.

[0069] In one embodiment, referring to FIGS. 7 and 8, in the illustrated embodiment, in order to avoid the non-uniformity of the temperature field due to the concentration of heat, the infrared burner 210 is arranged offset in the advancing direction of the glass 20 in the main body structure of the heating stage furnace body 200 as shown in FIGS. 7 and 8. From the perspective of temperature control, the heating stage furnace body 200 is divided into four areas, and an air flow stirring device 220 is provided for each area. As seen from the plan view of FIG. 8, in the width direction of the furnace, the infrared burners 210 are separately arranged on both sides.

[0070] In some embodiments of the present application, a plurality of air ducts 310 are provided in the soaking stage furnace body 300, and the plurality of air ducts 310 are configured to generate horizontal and parallel air flows on the upper and lower surfaces of the glass 20. Specifically, the soaking stage furnace body 300 includes a housing chamber 350 and air ducts 310. In one embodiment, a transmission roller 101 is provided on the bottom wall 351 of the housing chamber 350, and the transmission roller 101 is configured to transmit the glass 20.

[0071] The "strengthening" of the glass includes the processes of "heating" and "cooling". Before the glass enters the rapid cooling process, if the uniformity of the temperature on the surface of the glass is not well guaranteed, serious quality problems will occur in the glass during the rapid cooling process.

[0072] As mentioned in the background art, in the related art, generally, forced convection is provided in the heating stage. In such a way, when the glass is in a high-temperature softening state, an air flow with a certain speed and pressure forms "patterns" on the surface of the softening state glass. In the present application, by providing a soaking stage and constructing a horizontal and parallel air flow in the soaking stage, this problem is solved.

[0073] In addition to having the above-mentioned drawbacks, for the direct combustion heating of gas, the high-speed flowing air flow in the furnace has a serious impact on the "porous media burner" in forced convection.

[0074] The thermal conductivity of glass is low. On the premise of satisfying the production capacity, in order to complete the temperature uniformity of the glass within a predetermined time, a method of increasing the convective heat exchange efficiency / capacity must be considered. For the uniform heating technology of the air flow, in order to ensure the temperature uniformity of the product, (1) the air flow must be sufficiently turbulent, (2) and it is necessary to satisfy either of the two conditions that the air flow is sufficiently horizontal.

[0075] A sufficiently turbulent air flow needs to be ensured by a strong fan, and such an air flow is disadvantageous to the stability of the thin and light glass on the transmission roller 101. Furthermore, the heat insulation material in the furnace and the impurities existing in the furnace chamber are wrapped by the turbulent air flow and spread over the entire furnace chamber and the surface of the glass, resulting in problems that cannot be controlled in the surface quality of the glass.

[0076] In the present application, the soaking furnace body 300 with forced convection of "horizontal and parallel air flow" introduced after the heating furnace body 200 corresponds to the last heating and temperature adjustment process, and the required power is much smaller than the power of the heating stage, which requires that the power output of the heater 320 responds rapidly and can be continuously adjusted. In the present application, the heat source of the soaking furnace body 300 is an electric heating integrated box, and the electric heating integrated box is entirely pushed into the air duct.

[0077] In some embodiments of the present application, referring to FIGS. 9 and 10, the soaking furnace body 300 is divided into a plurality of stages in total. Exemplarily, it is divided into 4 stages in the drawings, and independent air ducts 310 are provided for each stage.

[0078] In one embodiment, the four-stage air ducts 310 are respectively provided in the accommodation chamber 350. The air ducts 310 have an air outlet 313 and an air suction inlet 314. The air outlet 313 is placed above and below the transmission roller 101 and is provided at the first end 1011 of the transmission roller 101 along the radial direction of the transmission roller 101. Thereby, the air blown out from the air outlet 313 reaches the first end 1011 of the transmission roller 101, blows out from the gap between the adjacent transmission rollers 101, and blows through the upper and lower surfaces of the glass 20 parallel to the transmission roller 101.

[0079] In one embodiment, the air suction inlet 314 is provided above and below the drive roller 101 and near the second end portion 1012 of the drive roller 101, and is configured to suck the air that has passed through the upper and lower surfaces of the glass 20.

[0080] In the soaking furnace body 300 of the present application, the air blown out from the air outlet 313 reaches the first end portion 1011 of the drive roller 101, is blown out from the gap between adjacent drive rollers 101, and can pass through the upper and lower surfaces of the glass 20 in parallel with the drive roller 101. Thereby, the upper and lower surfaces of the glass 20 can be horizontally and parallelly skimmed, and heat exchange with the glass 20 can be completed. Such a horizontal and parallel soaking method can extremely greatly improve the problem of non-uniform heating temperature on the surface of the workpiece.

[0081] In some embodiments of the present application, the above air duct 310 includes a centrifugal fan 311 and an air duct body. The centrifugal fan 311 rotates to suck air, and then the air flows in the air duct body and is blown out from the gap between the drive rollers 101, and is configured to skim the upper and lower surfaces of the glass 20 horizontally and in parallel to complete heat exchange with the glass 20. In one embodiment, the air duct body includes an air suction section air duct 3122 and an air blowing section air duct 3121. The air blowing section air duct 3121 has a first end connected to the outlet of the centrifugal fan 311 and an air outlet 313 opened at the second end. The air suction section air duct 3122 has a first end connected to the inlet of the centrifugal fan 311 and an air suction inlet 314 provided at the second end.

[0082] The air blowing section air duct 3121 has a first end connected to the outlet of the centrifugal fan 311 and a second end with an air outlet 313 opened. When the centrifugal fan 311 rotates at high speed, air is sucked in from the inlet of the centrifugal fan 311, swings into the air blowing section air duct 3121 from the tangential direction, flows in the air blowing section air duct 3121, then reaches the air outlet 313. The air blown out from the air outlet 313 reaches the first end portion 1011 of the transmission roller 101, collides with the side wall surface of the first end portion 1011, then has its direction changed, is blown out from the gap between adjacent transmission rollers 101, and blows through the upper and lower surfaces of the glass 20 parallel to the transmission roller 101. Thereby, it is realized to heat the work evenly horizontally and in parallel.

[0083] In one embodiment, referring to FIGS. 9 and 10, illustratively, in the embodiment illustrated in the present application, the shape of the above-mentioned accommodation chamber 350 presents a hexahedron. The transmission roller 101 is provided above the bottom wall 351, and the centrifugal fan 311 is provided on the ceiling wall 352. The inlet of the centrifugal fan 311 is located at the bottom of the centrifugal fan 311, and when the transmission roller 101 transmits the work, the inlet of the centrifugal fan 311 is located above the work.

[0084] In one embodiment, the air blowing section air duct 3121 includes a first partial air duct 31211 and a second partial air duct 31212. The first partial air duct 31211 is provided parallel to the transmission roller 101, the second partial air duct 31212 is provided perpendicular to the transmission roller 101, and the air outlet 313 is provided on the side wall surface of the second partial air duct 31212 close to the first end portion 1011 of the transmission roller 101.

[0085] In one embodiment, referring to FIGS. 9 and 10, in the embodiment illustrated in the present application, the first partial air duct 31211 is provided on the ceiling wall 352 facing the transmission roller 101, and the second partial air duct 31212 is provided on the side wall 353 of the accommodation chamber 350.

[0086] In one embodiment, the first partial air duct 31211 has a first end communicating with the outlet of the centrifugal fan 311, a second end connected to the inlet of the second partial air duct 31212, and the second end of the second partial air duct 31212 is the air outlet 313.

[0087] In one embodiment, in the illustrated embodiment, the first partial air duct 31211 and the second partial air duct 31212 are rectangular air ducts.

[0088] In some embodiments, the first partial air duct 31211 has a relatively small size at the first end communicating with the outlet of the centrifugal fan 311 and a relatively large size at the second end, whereby the first partial air duct 31211 generally presents a horn shape. The size of the internal passage of the second partial air duct 31212 is selected and set according to the overall length of the soaking furnace body 300, and the cover width of the blown air, i.e., the width of the workpiece passing through, is determined by the size of the internal passage of the second partial air duct 31212.

[0089] In some embodiments of the present application, the inlet of the centrifugal fan 311 is provided below the impeller of the centrifugal fan 311.

[0090] In some embodiments of the present application, the soaking furnace body 300 further includes a heater 320, and the heater 320 is configured to heat the air that has undergone heat exchange to a preset temperature. The heater 320 is provided below the impeller of the centrifugal fan 311, whereby the air sucked in by the rotation of the impeller first passes through the heater 320 and then enters the impeller of the centrifugal fan 311. The air that has passed through the upper and lower surfaces of the workpiece has undergone heat exchange with the workpiece. At this time, the temperature of the air drops, and the air can be heated again to the preset temperature through the heater 320.

[0091] In one embodiment, the temperature distribution of the air heated through the heater 320 as described above is non-uniform. The present application sucks the air heated through the heater 320 into the centrifugal fan 311 again, and through the stirring action of the impeller of the centrifugal fan 311, the non-uniform air after being heated through the heater 320 is sufficiently stirred and dispersed to achieve temperature uniformity. The air after being homogenized is sent into the air duct 310 again by the high-speed rotation of the centrifugal fan 311 to soak the workpiece. In this way, the circulation and soaking are realized, which is beneficial for energy saving and emission reduction.

[0092] Referring to FIGS. 9 and 10, in the embodiment illustrated in the present application, the heater 320 is provided on the side wall 353 of the accommodation chamber 350 facing the second partial air duct 31212.

[0093] In some embodiments of the present application, the air suction section air duct 3122 of the soaking furnace body 300 has a first end connected to the inlet of the centrifugal fan 311 and an air suction port 314 described above provided at the second end.

[0094] In some embodiments of the present application, the heating section 321 of the heater 320 is placed inside the air suction section air duct 3122.

[0095] By placing the heating section 321 of the heater 320 inside the air suction section air duct 3122, when the air passing through the upper and lower surfaces of the glass 20 passes through the air suction section air duct 3122, it can be heated by the heating section 321 of the heater 320, thereby improving the heating efficiency and reducing the energy consumption.

[0096] The air suction section air duct 3122 has a first end connected to the inlet of the centrifugal fan 311 and the above-mentioned air suction port 314 provided at the second end. Thereby, the air passing through the upper and lower surfaces of the glass 20 passes through the air suction section air duct 3122 and reaches the inlet of the centrifugal fan 311, is sucked into the centrifugal fan 311, stirred again, and circulated for soaking.

[0097] In some embodiments of the present application, the soaking furnace body 300 is provided with a plurality of air ducts 310, and along the transmission direction of the workpiece, the plurality of air ducts 310 are provided at intervals.

[0098] In the illustrated embodiment, referring to FIGS. 9 and 10, the soaking furnace body 300 has a total of four independently controlled air ducts, each of which is the first air duct, the second air duct, the third air duct, and the fourth air duct of the soaking stage. The cross-section of a single air duct of the soaking furnace body in the width direction is as shown in FIG. 10. The centrifugal fan 311 rotates at a high speed, and air is sucked in from the opening at the bottom of the impeller of the centrifugal fan 311 and ejected in the tangential direction. The air flows in the air duct body, is blown out from the gap between adjacent transmission rollers 101, skims the upper and lower surfaces of the glass 20 horizontally and in parallel, and the air blown out from each stage of the air duct covers the surface of the glass 20 passing through that stage, and heat exchange with the glass 20 can be completed. The temperature of the air after heat exchange drops to a certain extent and reaches a predetermined temperature again by heating with the heater 320 in the soaking furnace body 300. In fact, the temperature distribution of the air after being heated through the heater 320 in the soaking furnace body 300 is non-uniform, and such non-uniform air should not be directly blown onto the glass 20. In the present application, the impeller of the centrifugal fan 311 has a stirring effect at the same time, and sufficiently stirs and disperses the non-uniform air after being heated through the heater 320 in the soaking furnace body 300 to realize temperature uniformity. The air after being uniformized is sent into the air duct body again to complete the heating of the glass 20 and the temperature uniformity.

[0099] In some embodiments of the present application, the soaking furnace body 300 is divided into an upper soaking furnace body 330 and a lower soaking furnace body 340. The upper soaking furnace body 330 is provided above the transmission roller 101, and the lower soaking furnace body 340 is provided below the transmission roller 101.

[0100] By providing the preheating furnace body 100, the heating furnace body 200, and the soaking furnace body 300 in a two-stage structure up and down respectively, it is easy to install or remove the transmission roller 101 and maintain the equipment. In one embodiment, the above-mentioned transmission roller 101 can be selected from ceramic rollers commonly seen in this field.

[0101] In some embodiments of the present application, the above preheating furnace body 100, heating furnace body 200, and soaking furnace body 300 are each provided with a furnace body lifting device 400. The furnace body lifting device 400 is connected to the upper furnace body and is configured to lift the upper furnace body.

[0102] In some embodiments of the present application, a glass strengthening method is provided in which the glass strengthening heating furnace 10 according to any of the foregoing embodiments is employed to strengthen glass.

[0103] In some embodiments of the present application, strengthening the glass 20 by employing the glass strengthening heating furnace 10 according to any of the foregoing embodiments includes the following steps: In S1, the glass 20 is manually (or by an automated device) laid flat in a single layer on the material placement table, and the products are arranged side by side. In S2, the glass 20 is run by the transmission roller 101 so as to enter the preheating furnace body 100, and the preheating of the product is completed in the preheating furnace body 100 (the temperature is controlled within a certain range). In S3, the glass 20 begins to enter the heating furnace body 200, the temperature of the product rises to 600°C - 640°C, and after reaching the set temperature, the glass 20 continues to run at the set temperature. In S4, the glass 20 enters from the heating furnace body 200 into the soaking furnace body 300, and the circulating gas sweeps over the upper and lower surfaces of the glass 20 to heat the glass 20 and equalize the temperature. After the gas that has completed heat exchange with the glass 20 in a relatively low-temperature and non-uniform state is circulated to the heater 320, temperature rise and heat compensation are realized by the heating action of the heater 320. The strong stirring of the impeller of the centrifugal fan 311 realizes temperature equalization for the non-uniform gas. Due to the action of the centrifugal fan 311 and the air duct 310, it is blown onto the upper and lower surfaces of the glass 20 again.

[0104] The beneficial effect of the glass strengthening method of the present application is that since the glass is strengthened by adopting the glass strengthening heating furnace described above, the glass can be heated rapidly and uniformly, and it is applicable not only to the strengthening of ordinary glass, but also particularly applicable to the strengthening of coated glass and Low-E glass.

[0105] After obtaining the glass whose temperature has been raised and made uniform, the next process can be advanced.

[0106] Referring to FIGS. 13 to 16, the porous medium combustor described above will be described in detail.

[0107] First, still, through analysis, there are mainly the following several reasons restricting the application of the porous medium combustor to the high-temperature field.

[0108] (1) Among them, compared with medium and low temperatures, the "background radiation" of the furnace chamber due to the high furnace temperature is quite large. According to the knowledge related to radiation, radiation is related to the fourth power of temperature. The background radiation ability at a furnace temperature of 1000 °C is nearly 6 times that at a furnace temperature of 650 °C. In the heat transfer process in the furnace, as a heat source with a high temperature, the combustor transfers heat to the furnace chamber in the forms of "heat convection" and "radiation", and the furnace chamber also generates background radiation that increases with the increase of the furnace temperature for the combustor. In a high-temperature state, even the metal skeleton of the combustor made of a heat-resistant alloy material will have the "creep" phenomenon in the metal, and such deformation is irreversible.

[0109] (2) The structure of the porous medium combustor usually adopts the form of "heat-resistant metal skeleton + support of heat-insulating material" to "constrain" the porous medium in the combustor. Due to such a structural design, it is determined that the heat of the high furnace temperature is transmitted along the metal skeleton of the combustor. As a result, the temperature of the metal wall surface of the pre-mixing chamber body into which the mixed combustion gas of the combustor is injected is too high, and there is a risk of flashback.

[0110] Therefore, for the combustor developed based on the porous medium combustion technology in the related art, the part facing the furnace chamber is usually a metal skeleton, and after a long time of operation, deformation of varying degrees will appear in all cases. Especially when facing a high-temperature environment, the metal skeleton of such a combustor will lead to serious consequences. Therefore, this combustor cannot be applied to an environment with a high furnace temperature. In order to solve the application limitation that the porous medium combustor in the related art can only be applied to medium and low furnace temperatures and most of them are concentrated in the low-temperature field, and to expand the application range to the high-temperature field, the present application provides a porous medium combustor applied to an environment with a high furnace temperature, and through the design of the related structure, a structure with the cooling function of the original metal skeleton is protected.

[0111] In addition, due to being restricted by the characteristics of two types of combustion, namely "premixed combustion" and "porous medium combustion", in the related art, the power adjustment ratio of the porous medium combustor (the ratio value of the maximum power and the minimum power at which the combustor operates stably) is generally fixed, or the adjustment range is narrow, that is, the gas flow rate does not change and is fixed, which also limits the application of the combustor.

[0112] In the related art, the methods and characteristics for realizing power adjustment based on the heat equipment of the porous medium combustor are as follows.

[0113] (1) A certain amount of air is required for gas combustion. The air-fuel ratio is the ratio value of air to gas, and the ratio value of the two is usually fixed. By slightly adjusting the amount of air (adjusting the air-fuel ratio), the power adjustment of a single combustor can be realized. However, the fluctuation range of the power output of the combustor is very narrow. When the amount of air is reduced, incomplete combustion of the gas will be caused, which will in turn lead to the generation of toxic CO gas.

[0114] (2) The heater group is composed of a plurality of combustor modules, and by opening and closing the combustor modules, the output of the power of the entire heater group can be realized. However, the temperature distribution of a single heater group is non-uniform, which results in a non-uniform temperature distribution of the heat equipment, and a uniform temperature field cannot be constructed.

[0115] Therefore, in order to solve the problems of the fixed power of the combustor and the extremely small power adjustment ratio in the related art, it is necessary to improve the adjustment ability of the combustor from the perspective of its own design.

[0116] The infrared combustor 210 of this embodiment includes a housing, and the housing has a chamber, an air inlet 2112 and a heat dissipation port 2113 communicating with the chamber. The direction from the air inlet 2112 to the heat dissipation port 2113 is defined as the air intake direction. In the chamber, a premixing area 2115, a flashback prevention area 218 and a combustion area 219 are sequentially arranged along the air intake direction.

[0117] The housing includes an inner cylinder 2114 and a cover plate 2111 having the air inlet 2112. The air inlet 2112 is configured to input a mixed combustion gas of combustion-supporting air and gas. The number of the air inlets 2112 may be one or more, for example, two, three, etc. The cover plate 2111 is covered at one end of the inner cylinder 2114 and jointly forms a chamber with the inner cylinder 2114. In this embodiment, the housing is made of a metal material. The space inside the inner cylinder 2114 is cylindrical. The housing and the cover plate 2111 are square. The number of the air inlets 2112 is one and is located at the center position of the cover plate 2111. The inner cylinder 2114 and the cover plate 2111 are fastened and connected in the form of a flange + a sealing gasket.

[0118] The main role of the premixing area 2115 is to remix and disperse the mixed combustion gas of gas and air entering from the intake port 2112 so that the mixed combustion gas is further mixed and dispersed before uniformly entering the backfire prevention area 218. A gas dispersion plate with gas dispersion holes is provided in the premixing area 2115. The gas dispersion plate is connected to the housing, and the orthographic projection of the intake port 2112 is located on the gas dispersion plate. In this embodiment, the orthographic projection refers to the projection along the intake direction, and the orthographic projection of the intake port 2112 is located at the center of the gas dispersion plate. After passing through the gas dispersion holes of the gas dispersion plate, the mixed combustion gas is uniformly dispersed in the premixing area 2115, and then uniformly passes through the gas passage of the heat insulation material layer and is distributed in the porous medium material layer 214. Thereby, the mixed combustion gas burns uniformly in the porous medium material layer 214, and the uniformity of combustion and heating is enhanced.

[0119] The main role of the backfire prevention area 218 is to partition the premixing area 2115 and the combustion area 219 to achieve the purpose of preventing backfire. The backfire prevention area 218 is filled with a heat insulation material layer having a gas passage. The heat insulation material layer further mixes the mixed combustion gas entering from the premixing area 2115 and distributes it uniformly, and then transports it into the combustion area 219 for combustion. The heat insulation material layer has a gas passage, and the thickness along the intake direction is 100 mm to 200 mm. Usually, the heat insulation material layer is composed of at least two heat insulation material plates 213 arranged in a stacked manner along the intake direction. The thickness of a single heat insulation material plate 213 is 50 mm to 100 mm, and the gas passages of any two adjacent heat insulation material plates 213 therein communicate correspondingly to form a complete gas passage. In this embodiment, the heat insulation material layer is composed of two heat insulation material plates 213. The gas passages of the two heat insulation material plates 213 communicate correspondingly to form a complete gas passage. The complete gas passage is provided to penetrate along the intake direction and is arranged in the central region of the heat insulation material layer.

[0120] By processing through-holes in the thickness direction of the heat insulation material layer, the premixed gas is allowed to enter the porous medium material through these through-holes. These through-holes need to achieve a uniform distribution of the air flow, while the diameter and number of the apertures (corresponding to the total area of the apertures) need to satisfy the relevant combustion rules. In the embodiments of the present application, the aperture ratio of the gas passage to the heat insulation material layer is 1% - 5%.

[0121] The heat insulation material layer is made of a refractory material that can withstand temperatures from 900°C to 1400°C, such as a ceramic plate, etc., and can be selected according to actual needs, and is not limited here. The diameter of the gas passage in the heat insulation material layer is 1.5 mm - 4 mm. Although not limited to this, in this embodiment, it is specifically 3 mm, and the depth-to-diameter ratio (depth / diameter) of the gas passage is large, generally 30 - 80:1. Thereby, the effect of preventing flashback is enhanced.

[0122] When the depth-to-diameter ratio of the gas passage in the heat insulation material layer of the flashback prevention area 218 is large enough, it is possible to adjust the power of the combustor by synchronously decreasing or increasing the gas and air, and the large depth-to-diameter ratio eliminates the need to worry about the occurrence of flashback phenomena, increases the pressure of the mixed combustion gas, and can make the flow rate of the gas higher than the flame propagation speed. At the same time, high combustion efficiency and low pollutant emissions can be considered.

[0123] The main role of the combustion area 219 is combustion. A porous medium material layer 214 is provided in the combustion area 219. The gas passage of the heat insulation material layer communicates the premixed area 2115 with the porous medium material layer 214. The porous medium material layer 214 is configured to receive the mixed combustion gas mixed and dispersed from the heat insulation material layer and burn it. The temperature of the back surface of the heat insulation material layer (the surface in contact with the premixed area 2115) should be lower than the ignition point of the gas. In this embodiment, the porous medium material layer 214 is arranged in the central region of the heat insulation material layer. The porous medium material layer 214 faces the heat dissipation port 2113 and has a combustion surface configured to output flue gas and heat. There is a certain distance between the combustion surface and the heat dissipation port 2113. At a position (combustion area 219) close to the heat dissipation port 2113 in the chamber, a heat insulation material support layer 2153 configured to support the heat insulation material is provided. The heat insulation material support layer 2153 has a heat dissipation passage corresponding to the porous medium material layer 214, and the heat dissipation passage communicates with the heat dissipation port 2113.

[0124] The material of the porous medium material layer 214 includes silicon carbide SiC, but is not limited thereto. The emissivity of SiC is about 0.9, which is much higher than that of general metal alloy heating materials, and the radiative heating effect is better. Of course, other refractory materials may also be used, and are not limited here. The structure includes a foam structure, a honeycomb structure, an array structure, etc., but is not limited to these.

[0125] The porosity of the porous medium material layer 214 is 50% - 90%. Based on this, the thickness of the porous medium material layer 214 is controlled to be 15 mm - 30 mm.

[0126] By controlling the key data of the above heat insulation material layer and the porous medium material layer 214, it is realized that the adjustment ratio of the combustor reaches a high range of 1 - 5:1 from a very small one.

[0127] According to the above content, in a high furnace temperature state, the background radiation in the furnace chamber is quite strong, which means that the radiation power on the combustor in the furnace chamber is also considerable. When the radiation power of this part is reflected on the combustor, the side of the combustor facing the furnace chamber is receiving high temperature and heat input. The housing of the combustor often adopts a heat-resistant steel skeleton, and due to the good thermal conductivity of steel, it is determined that the heat will rapidly transfer to the metal skeleton of the entire combustor. Even for the metal skeleton of the combustor made of heat-resistant alloy materials, the "creep" phenomenon occurs in the metal at high temperature, and such deformation is irreversible. Also, the high-temperature environment weakens the heat insulation effect of the flashback prevention area 218, and thus weakens the flashback prevention effect. Therefore, the overall temperature of the housing (metal skeleton) and the flashback prevention area 218 should be stabilized at a controlled level.

[0128] To control the overall temperature of the housing, a cooling intervening layer 212 for accommodating a cooling medium is provided on the outer periphery of the housing of the infrared combustor 210. The cooling intervening layer 212 is at least surrounded by a part of the premixing area 2115, a part of the flashback prevention area 218, and a part of the combustion area 219. As an embodiment, an outer cylinder 2121 is fitted on the outer periphery of the inner cylinder 2114, and a cooling intervening layer 212 is formed between the inner cylinder 2114 and the outer cylinder 2121. In this embodiment, the inner cylinder 2114 and the outer cylinder 2121 are each cylindrical. The outer cylinder 2121 encloses most of the premixing area 2115, the entire flashback prevention area 218, and most of the combustion area 219 of the inner cylinder 2114, and only encloses the areas located at the top and bottom ends of the inner cylinder 2114. Both ends of the outer cylinder 2121 are welded together with the inner cylinder 2114 through sealing plates respectively.

[0129] According to the operating process of the combustor, the mixed air and gas obtained before entering the combustor, or the air and gas mixed in the premixing area 2115, stay temporarily in the premixing area 2115 and then enter the porous medium material layer 214 through the gas passage of the heat-insulating material layer for combustion. The premixing area 2115 serves as a combustible gas container, and it is necessary to ensure that the temperature at any point in the premixing area 2115 is not too high. Otherwise, a combustion phenomenon, i.e., flashback, will occur in the premixing area 2115.

[0130] To timely cool down the premixing area 2115, the cooling intervention layer 212 is provided with a cooling inlet 2122 and a cooling outlet 2123 for the cooling medium, and the cooling inlet 2122 and the cooling outlet 2123 are close to the air inlet 2112.

[0131] This application selectively uses different cooling media for different furnace temperature requirements. As an embodiment, the furnace temperature is required to be 700°C or lower, and a gas is employed as the cooling media. Referring to FIG. 15, the infrared burner 210 further includes a combustion-supporting air pipeline 2161 communicating with the air inlet 2112. The combustion-supporting air pipeline 2161 is connected to the air-fuel mixer 2165 via a combustion-supporting fan 2162 and is configured to inject the air in the combustion-supporting air pipeline 2161 into the air-fuel mixer 2165. Gas is also injected into the air-fuel mixer 2165 and mixed. The obtained premixed gas enters the chamber of the burner through the air inlet 2112. The combustion-supporting air pipeline 2161 and the cooling inlet 2122 communicate with each other via a first branch path 2163, and the combustion-supporting air pipeline 2161 and the cooling outlet 2123 communicate with each other via a second branch path 2164. The connection points of the first branch path 2163 and the second branch path 2164 with the combustion-supporting air pipeline 2161 are located between the combustion-supporting fan 2162 and the air-fuel mixer 2165, and the connection point of the second branch path 2164 with the combustion-supporting air pipeline 2161 is closer to the air-fuel mixer 2165 and the air inlet 2112 than the connection point of the first branch path 2163 with the combustion-supporting air pipeline 2161. The low-temperature combustion-supporting air passes through the first branch path 2163 and enters the cooling inlet 2122, exchanges heat with the inner cylinder 2114 in the cooling intermediate layer 212, and the heated combustion-supporting air is discharged into the second branch path 2164 through the cooling outlet 2123. Since the connection point of the second branch path 2164 with the combustion-supporting air pipeline 2161 is closer to the air-fuel mixer 2165, the heated combustion-supporting air enters the air-fuel mixer 2165, and preheating of the gas can be realized in the air-fuel mixing process.

[0132] As an embodiment, when the furnace temperature is required to be 700°C to 1150°C, if the furnace temperature is in the high-temperature range greater than 1000°C, liquid cooling technical means should be adopted, and the cooling media can be selected from water or oil to achieve stable control of the overall temperature of the burner housing. Referring to FIG. 16, due to structures such as the air-fuel mixer 2165, the functions of forming the premixed gas and injecting it into the burner are retained. The infrared burner 210 further includes a cooling water tank 2171 and a hot water tank 2712. The cooling water tank 2171 communicates with the cooling inlet 2122, and the hot water tank 2712 communicates with the cooling outlet 2123.

[0133] In the operation process of the combustor, due to the difference in the thermal conductivity of the materials, the heat quantity of the heat insulation material plate 213 is conducted to the inner cylinder 2114, and the cooling medium in the cooling intermediate layer 212 cools down the inner cylinder 2114, so that the housing of the combustor can be prevented from deforming at high temperature. At the same time, the difficulty in achieving a high adjustment ratio is to prevent flashback when the mixed combustion gas has a low flow rate and always make the flow rate of the mixed combustion gas higher than the flame propagation speed. The contact surface between the heat insulation material plate 213 and the porous medium material layer 214 is maintained in a low-temperature state, the temperature is lower than the ignition point of the gas, and when the power of the combustor is reduced by reducing the flow rate of the mixed combustion gas, the low temperature can reduce the flame propagation speed. Even when the flow rate of the mixed combustion gas is small, the flashback prevention effect can be maintained, and the purpose of increasing the adjustment ratio of the combustor can be achieved.

[0134] To ensure real-time monitoring of the temperature of the premixing area 2115, a thermocouple 2151 inserted into the premixing area 2115 is further provided, and the detection end of the thermocouple 2151 is close to the inner wall of the premixing area 2115.

[0135] To perform heat insulation and heat preservation on the whole housing, a heat preservation material layer 2152 is provided on the outer periphery of the cooling intermediate layer 212.

[0136] To support the housing part, the infrared combustor 210 is further provided with a bottom heat insulation panel 2154 configured to support the housing and the cooling intermediate layer 212. The bottom heat insulation panel 2154 has heat dissipation holes corresponding to the heat dissipation ports 2113 and does not affect the release of heat quantity.

[0137] Generally, a bottom panel 2156 made of a metal material for support is further provided below the heat insulation material support layer 2153 of the combustor. Since the bottom panel 2156 faces the high temperature inside the furnace, receives heat and expands to cause a high-temperature creep effect, a warping phenomenon occurs on the bottom panel 2156. Once such deformation becomes excessive, the heat insulation material support layer 2153 is destroyed by the force caused by the deformation, and consequently, the porous media material layer 214 placed on the heat insulation material support layer 2153 becomes unstable. Therefore, in this embodiment, a reinforcing rib 2157 is newly added, and welding reinforcement is performed on the bottom panel 2156 of the combustor. A part of the reinforcing rib 2157 is welded and fixed to the inner cylinder 2114, and another part is welded and fixed to the bottom panel 2156.

[0138] In this embodiment, the heat insulation material layer and the porous media material layer 214 are in close contact with each other. A pressing mechanism 2155 arranged along the intake direction is provided in the premixing area 2115. The pressing mechanism 2155 has a first end connected to the housing and a second end that abuts against the heat insulation material layer to apply pressure so that the heat insulation material layer and the porous media material layer 214 are always in close contact. The number of the pressing mechanisms 2155 is three, and the three pressing mechanisms 2155 are provided surrounding the axis of the housing and are distributed at equal intervals. In one embodiment, the number of the pressing mechanisms 2155 is four, and they are provided at the four corners of the housing. The pressing mechanism 2155 keeps the heat insulation material layer and the porous media material layer 214 in a close contact state all the time, avoiding the generation of a gap between the heat insulation material layer and the porous media material layer 214 due to the expansion of the combustor receiving heat during the operation process, and avoiding problems such as rapid heat diffusion due to the gap and poor combustion effect.

[0139] The operation process of the infrared combustor 210 is as follows.

[0140] The premixed gas of the combustion-supporting air and the gas enters the chamber from the air inlet 2112 and stays temporarily in the premixing area 2115. The premixed gas further completes the mixing in the form of turbulent flow in the premixing area 2115 while cooling the surrounding wall surfaces to a certain extent.

[0141] The premixed gas enters into the porous medium material layer 214 along the gas passage in the heat insulation material layer and completes combustion within the porous medium material layer 214. Since the ignition of the gas was carried out initially, with the continuous entry of the premixed gas, the combustion process inside the porous medium material layer 214 continues, and the porous medium material in the normal operating state presents an infrared state.

[0142] The cooling medium enters the inner cylinder 2114 from the cooling inlet 2122, makes a circular motion around the inner cylinder 2114 within the cooling intervening layer 212, and then is discharged from the cooling outlet 2123 to achieve temperature control for the entire housing. The thermocouple 2151 evaluates the cooling effect of the cooling medium by monitoring the temperature of the premixed area 2115 in real time.

[0143] In the description of this specification, the description of reference terms such as "some embodiments", "other embodiments", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in an appropriate manner.

Claims

1. A preheating stage furnace body having a feed port provided with a total exhaust port, divided into a plurality of stages along the advancing direction of the glass, and each stage is provided with a smoke suction port and a flue gas injection joint respectively; A heating stage furnace body provided with a plurality of infrared burners which are porous medium burners; A soaking stage furnace body provided behind the heating stage furnace body along the advancing direction of the glass, and a plurality of air ducts are provided therein which are configured to generate horizontal and parallel air flows on the upper and lower surfaces of the glass; and it is provided with, The preheating stage furnace body is configured to suck the flue gas of the heating stage furnace body through the smoke suction port and send the sucked flue gas into the preheating stage furnace body through the flue gas injection joint. A glass strengthening heating furnace.

2. It further comprises a plurality of transmission rollers sequentially passing through the inside of the preheating stage furnace body, the inside of the heating stage furnace body, and the inside of the soaking stage furnace body. In the preheating stage furnace body, along the advancing direction of the glass, a plurality of flue gas injection air knives are respectively provided above and below the transmission rollers, and the plurality of flue gas injection air knives above and below the plurality of transmission rollers and the plurality of transmission rollers are arranged offset in the height direction. The flue gas injection joint is configured to send the sucked flue gas into the plurality of flue gas injection air knives. The glass strengthening heating furnace according to Claim 1.

3. The caliber of the air knife air outlet of the plurality of flue gas injection air knives is shrinking. The glass strengthening heating furnace according to Claim 2.

4. In the preheating stage furnace body, an increaser having a passage with a venturi tube structure connected to the air knife air outlet of the plurality of flue gas injection air knives is provided. The glass strengthening heating furnace according to Claim 3.

5. The plurality of infrared burners are arranged offset above and below the transmission rollers along the advancing direction of the glass. The glass strengthening heating furnace according to Claim 2.

6. In the heating section furnace body, an air flow stirring device is further provided at an interval from the plurality of infrared burners along the advancing direction of the glass. The glass strengthening heating furnace according to claim 5.

7. The air duct has an air outlet and an air suction inlet. The air outlet is disposed above and below the driving roller and is provided at the first end of the driving roller along the radial direction of the driving roller. Thereby, the air blown out from the air outlet reaches the first end of the driving roller, is blown out from the gap between the adjacent driving rollers, and can blow through the upper and lower surfaces of the glass in parallel with the driving roller. The air suction inlet is provided above and below the driving roller and is configured to suck in the air that has blown through the upper and lower surfaces of the glass near the second end of the driving roller. The glass strengthening heating furnace according to claim 2.

8. The air duct includes a centrifugal fan and an air duct body having an air suction section air duct and an air blowing section air duct. The centrifugal fan is configured to suck in an air flow by rotating and then swing out the air flow so as to flow into the air duct body. The air blowing section air duct has a first end connected to the outlet of the centrifugal fan and an air outlet opened at the second end. The air suction section air duct has a first end connected to the inlet of the centrifugal fan and an air suction inlet provided at the second end. The glass strengthening heating furnace according to claim 7.

9. The air blowing section air duct includes a first partial air duct provided in parallel with the driving roller and a second partial air duct provided perpendicular to the driving roller. The air outlet is provided on the side wall surface of the second partial air duct close to the first end of the driving roller. The glass strengthening heating furnace according to claim 8.

10. The soaking section furnace body further includes a heater. The heater is provided below the impeller of the centrifugal fan, whereby the air sucked in by the rotation of the impeller passes through the heater first and then enters the impeller. The glass strengthening heating furnace according to claim 8.

11. The heating part of the heater is placed in the air suction stage air duct. The glass strengthening heating furnace according to claim 10.

12. The air suction port is provided on the side wall surface close to the second end of the transmission roller of the air suction stage air duct. The glass strengthening heating furnace according to claim 8.

13. The preheating stage furnace body, the heating stage furnace body, and the soaking stage furnace body are each divided into an upper furnace body provided above the transmission roller and a lower furnace body provided below the transmission roller. The glass strengthening heating furnace according to claim 1.

14. The porous medium combustor includes a housing having a chamber, an air inlet, and a heat dissipation port communicating with the chamber. The direction from the air inlet to the heat dissipation port is defined as the air intake direction. In the chamber, a premixing area, a flashback prevention area, and a combustion area are sequentially arranged along the air intake direction. The flashback prevention area is filled with a heat insulation material layer, and a porous medium material layer is provided in the combustion area. The heat insulation material layer has a gas passage communicating the premixing area and the porous medium material layer. A cooling intervening layer configured to accommodate a cooling medium is provided on the outer periphery of the housing. The cooling intervening layer is at least wrapped by a part of the premixing area, a part of the flashback prevention area, and a part of the combustion area. The glass strengthening heating furnace according to claim 1.

15. The housing includes an inner cylinder and a cover plate having the air inlet. The cover plate is provided at one end of the inner cylinder body, forms the chamber jointly with the inner cylinder body, an outer cylinder body is fitted on the outer periphery of the inner cylinder body, and the cooling intervening layer is formed between the inner cylinder body and the outer cylinder body. The glass strengthening heating furnace according to claim 14.

16. In the cooling intervening layer, a cooling inlet and a cooling outlet of the cooling medium close to the air inlet are provided. The glass strengthening heating furnace according to claim 14.

17. The glass strengthening heating furnace further includes a combustion-supporting air pipeline communicating with the air inlet. The combustion-supporting air pipeline and the cooling inlet communicate with each other through a first branch path, the combustion-supporting air pipeline and the cooling outlet communicate with each other through a second branch path, and the connection point between the second branch path and the combustion-supporting air pipeline is closer to the air inlet than the connection point between the first branch path and the combustion-supporting air pipeline. The glass strengthening heating furnace according to claim 16.

18. The glass strengthening heating furnace further includes a cooling water tank communicating with the cooling inlet and a hot water tank communicating with the cooling outlet. The glass strengthening heating furnace according to claim 16.

19. The porous medium combustor A heat preservation material layer is provided on the outer periphery of the cooling intervening layer. At a position close to the heat dissipation port in the chamber, a heat insulation material support layer is provided which is configured to support the heat insulation material layer and has a heat dissipation passage communicating with the heat dissipation port corresponding to the porous medium material layer. The glass strengthening heating furnace further includes a bottom heat insulation panel which is configured to support the housing and has a heat dissipation hole corresponding to the heat dissipation port. The glass strengthening heating furnace adopts at least one of the following settings: further including a thermocouple inserted into the premixing area. The glass strengthening heating furnace according to claim 14.

20. The ratio of the depth to the diameter of the gas passage of the heat insulating material layer is 30:1 to 80:

1. The glass toughening furnace according to claim 14.

21. It is carried out by adopting the glass toughening furnace according to any one of claims 1 to 20. On the side material placement table, the glass is manually (or by an automated device) laid flat in a single layer, and the products are arranged. The glass is transported to the preheating stage furnace body by a transmission roller, and the preheating of the product is completed in the preheating stage furnace body. The glass is transported to the heating stage furnace body, and the temperature of the glass in the heating stage furnace body is raised to the set temperature of 600°C to 640°C. The glass enters from the heating stage furnace body into the soaking stage furnace body, and the circulating gas sweeps the upper and lower surfaces of the glass to heat the glass and equalize the temperature. A glass toughening method characterized by the above.

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