• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a glass sheet tempering furnace with a glass plate conveyor, first convection blowing means for heating a glass sheet with hot air jets blown on at least one surface thereof, the first convection blowing means comprising a blower the surface has blow-through openings (9) from which air is discharged as jets towards the glass sheet, air-heating electric resistors (8) inside the blow housings, and other convection blowing means for directing pressurized air from outside the tempering furnace to blow nozzles (11) air jets for the first convection blowing means, in which the electrical resistors and blowing housings of the first convection blowing devices form a number of separately adjustable blowing ranges for the length and width of the tempering furnace; in the unidirectional direction, in which the heating effect of the air jets on the glass sheet is arranged to be controlled by adjusting the electric power supply to the electric resistors, and the blow nozzles (11) of the second convection blowing means by adjusting the supply to the blow nozzles.
    公开号:FI20195208A1
    申请号:FI20195208
    申请日:2019-03-21
    公开日:2020-09-22
    发明作者:Kyösti Keto；Jukka Vehmas
    申请人:Glaston Finland Oy；
    IPC主号:
    专利说明:

    The present invention relates to an oven for heating glass sheets for tempering. The object of the present invention is to substantially improve the quality of tempered glass sheets and the ability of the tempering oven to evenly heat increasingly difficult glass sheets.
    BACKGROUND OF THE INVENTION Tempering or heating furnaces for glass sheets in which the glass sheets move in one direction or back and forth on rotating ceramic rolls and from which they pass successively, side by side or in mixed glass loads along the roll path to a tempered cooling unit at the rear of the furnace are generally
    A furnace with a roller track is referred to in the art as a roller oven, for example.
    In ovens based on air support technology, the glass plate floats supported by a thin air mattress - and only touches the rollers or other conveying members of the conveyor track at one of its side edges.
    The glass sheets are heated in a tempering furnace from the factory temperature to a tempering temperature of 610-680 ° C depending on the thickness of the glass.
    The typical oven temperature is 700 * C.
    Typically, the heating of a glass sheet takes 40 s per millimeter of glass thickness, i.e. for example 160 s for a glass thickness of 4 mm.
    The thickness of the tempered glass sheets is usually between 1 and 25 mm.
    In a tempering furnace, heat is transferred to the glass by radiating from the inner surfaces of the furnace, by convection from the air, and directly due to the points of contact between the conveyor and the glass plate.
    In convection (more specifically forced convection), air currents are applied to the surfaces of the glass sheet by means of flow machines. a 25 - Convection convection means fans by circulating the air in the oven to- obtained air blowing towards the glass plate.
    In compressed air convection, the blowing towards the glass N is carried out by directing pressurized air to the furnace from outside the furnace.
    In recirculated air = convection, the blowing pressure in the furnace is typically 100 to 2000 Pa and in compressed air convection 0.1 to 5 bar.
    The diameters and numbers of the air vents in the compressed air convection are clearly smaller than in the convection convection.
    Problems with compressed air convection relative to circulating air convection include energy losses and inefficiency, especially in the final stages of heating, as the furnace air cools.
    The main problem is the lack of convection capacity, which makes it impossible or requires a disproportionately long heating time for the top and bottom surfaces of the latest glass sheets, which are increasingly coated to reflect heat radiation. The advantages of compressed air convection over circulating air convection are very fast adjustability and cheaper equipment.
    - From the point of view of the quality of tempered glass sheets, it is important that the glass sheets heat evenly in the oven. In heating, the surfaces of the glass sheets heat up faster than the average thickness, i.e. a thickness profile in the thickness direction is formed in the glass sheet. The temperature profile should be sufficiently symmetrical, i.e. the top and bottom surfaces of the glass plate should heat at about the same rate. The difference in heating rate between the top and bottom results in a momentary deflection of the glass during heating due to the difference in thermal expansion of the surface layers. This bending causes quality problems such as white haze. Uncoated or so-called clear glass absorbs the heat radiation from the oven quite effectively. It is therefore particularly challenging to heat glass, the other surface of which, usually the upper surface, is coated with coatings that strongly reflect heat radiation. Such - selective and low-emissivity coatings are commonly used, for example, in windows to reduce the energy consumption of buildings. Considering the practical quality and capacity requirements, heating a low-emissivity coated glass sheet is impossible without convection, which compensates for the difference in radiant heating of the surface of the clear and coated glass sheet. Convection is also an excellent help in heating clear - glass sheets.
    In the tempering furnace of reference EP2368855A2, the air recirculated by the fan in the furnace flows through the electrical resistor in the blow housing and heats up before being discharged from the blow openings as a shower towards the glass. The heating effect of the air jets on the glass sheet depends on the temperature of the jets, which depends on the electric current supplied to the resistor. The resistor in the blow housing radiates heat to the nozzle cover, which radiates heat to the glass plate. Thus, the radiant heating of the furnace must also be controlled by the same O electric heater. N In the tempering oven of reference FI120734B, the glass plate is heated by convection blowing and radiant heating above and below. The tempering furnace has several N 30 nozzle tubes - in succession and in parallel. The nozzle tubes are used to blow compressed air into the surface of the glass plate with compressors outside the furnace & the blowing pressure of each nozzle tube can be adjusted for each nozzle tube by valves outside the furnace. N The adjustment is based on information about the form of glass plate loading, which is obtained with the machine vision solution described in the reference. The convection blow matrix described in the reference consists of
    From 16 separate control ranges, the blowing pressures of which can be adjusted by means of transverse and longitudinal control valves.
    In the tempering furnace of reference FI120036B, the same glass surface is blown by both circulating and compressed air convection.
    The recirculating air convection device consists of successive transverse - full-width and blowing pipes of the furnace and the compressed air convection device consists of successive individually adjustable blowing pipes 1 to 2 m long, several of which are in the width direction of the furnace.
    The side and end edges of the glass sheet tend to heat up slightly faster than the central area of the glass sheet and more in the tempering furnace, because the surfaces of the furnace radiate into them - they are less stressed and thus cool during the heating cycle.
    Sometimes the surfaces of the toughened glass sheets are only partially painted or the low emissivity coating is removed from the edge areas.
    Uneven heating of the surface of the glass sheet due to these reasons, among others, causes quality problems such as an increase in anisotropy and uneven pattern of breakage.
    To solve the problems in the edge areas of the glass sheet - different heating is required compared to the rest of the glass sheet area.
    Prior art solutions to solve the problems are not sufficient.
    In order to solve the problems of the prior art, the invention relates to a glass sheet tempering furnace with a glass sheet conveyor, first convection blowing means above the conveyor for heating the glass sheet with hot air jets blown on its upper and / or lower surface, the first convection blowing means comprising tempering , air ducts for supplying air from the fan to the blow housings, the lower surface of which has first blow openings from which air is discharged as jets towards the top and bottom of the glass sheet, air heating electric heaters inside the blow ducts, and second convection blown means the air can be led to the second N blow nozzles, from which the air is discharged as jets towards the upper and / or lower surface of the glass plate, and the electric resistors form a matrix-like individually adjustable N resistance field, whereby the heating effect of the air jets the glass plate is arranged to be adjustable by adjusting the electric power supply to the electric resistors, and the blow nozzles of the second N 30 convection blowing means of the tempering furnace form matrix separately and obtainable blowing areas.
    In the tempering furnace according to the invention, at least one of the glass loading, primarily above it, has a dense matrix-adjustable circulating air convection for uniform heating of the glass sheets, and a dense matrix-adjustable compressed air convection for improving the heating application.
    Such a combination - increases the ability to direct the heating of the furnace when two separate convection systems are used for the widthwise profiling of the heating of the glass sheet, one of which can also apply convection inside the glass sheet in the direction of movement of the glass sheet.
    This convection capacity of the furnace allows for more even and controlled heating of the glass sheets, which improves the quality of the finished tempered glass.
    The heating time is also shortened.
    In the tempering furnace according to the invention, the main heating of the glass sheet is treated by convection convection and rain heating and the aim is to adjust the heating rate of the upper and lower surfaces sufficiently the same so that the glass sheet remains straight in the furnace.
    A sufficiently dense matrix-like separate adjustability of the recirculating air convection helps in the success of the above-mentioned main heating, when the heat is automatically transferred to the control area according to the local load, i.e. the heat transferred to the glass.
    This also prevents the area of the glass-free oven from heating above the set value, so that the oven receives the next glass sheet or glass load in balance.
    The width and longitudinal profiling of the furnace is performed by compressed air convection and the setpoints of the recirculating air convection control sensors can be the same throughout the control matrix.
    Such a combination of controls allows more controlled heating of the successive heating of the glass chips and a reduction of the random variation of the heating, as a result of which the average quality of the tempered glass sheet is improved.
    Recirculated air convection can also be used for widthwise profiling of heating, which is achieved, for example, by setting lower setpoints on the> resistors (thermocouples) on the side edges of the glass sheet than on the 0 resistors between them.
    However, profiling as described above is only possible when the glass sheets of the glass loading are about the same size and arranged in successive approximately straight rows, i.e. their side edges are on about the same line of movement of the glass.
    In addition, in subsequent glass loading, the need for profiling may be different or at a special point in the oven, and the O oven will not have time to equilibrate in temperature without additional delay time before it enters the oven.
    In this case, the profiling of the previous glass load also partially affects the> new glass load, but the area of influence is incorrect.
    By momentarily changing the control values of the resistance field heating the convection air convection air, it is not possible to prevent the front and rear ends of the glass plate from overheating in relation to the rest of the glass length, as the resistance current is only reflected in the heating with a delay of 5 ° to the other glass. . Thus, the compressed air convection according to the invention is used whenever the successful heating of the glass sheet requires longitudinal heating of the glass sheet or a rapid momentary increase in convection during heating, e.g. to prevent the glass sheet from bending.
    The above-mentioned object of the invention is achieved according to the present invention by combining a matrix-adjustable circulating air convection for performing uniform heating of the glass sheets, and a matrix-adjustable compressed air convection for improving the heating alignment.
    In the patent application, a matrix-adjustable convection blow system - refers to such convection blow means which are divided into separately adjustable parts in both the length and width directions of the tempering furnace. The sub-areas of the individually adjustable matrices are preferably short and narrow, which improves the matrix-like adjustability and leads to the benefit sought by the invention. It is essential that the heating of the glass moving in the furnace can be controlled both in the length and width direction of the glass, i.e. convection can be applied in a matrix within the surface area of the glass sheet. The small size of the control area is mainly limited by the increasing costs due to the number of control areas. Preferably, some sort of alignment is achieved for a glass plate 0.5 m wide and long, and at least satisfactory alignment of convection is achieved for a glass plate 1 m wide and long. The length of the glass sheets 25 heated by the device in the direction of movement of the glass in the oven is generally between 0.25 and 6 m and the width 0.1> - 3.3 m. The width of the heating area of the oven is generally between 1.2 and 3.5 m and the length 4 - 10 & m. One glass load can have dozens of glass sheets depending on their size.
    Preferred embodiments of the present invention are set out in the dependent claims.
    x 30 - The invention will now be described in more detail with reference to the accompanying drawings, in which: Figure 1 shows a device according to a preferred embodiment of the invention seen from the side (in the z direction),
    Fig. 2 shows the device according to Fig. 1 seen from the end (in the x-direction), and Fig. 3 shows the blow housings and blow nozzles according to the embodiment shown in Fig. 1 seen from below (as seen in the y-direction).
    Fig. 4 illustrates the size of the individually adjustable blowing zones - Fig. 5 shows a device according to an alternative embodiment of the invention Fig. 6 shows schematically a device according to the invention Figs. 1 and 2 show a device according to the invention for heating glass sheets for tempering. The appliance includes a tempering oven marked with a reference number
    1. The tempering furnace 1 has a longitudinal and a width direction, and the glass plate moves there from the loading table. A conveyor 2 is arranged in the tempering furnace 1, which is e.g. a roller track on which the glass sheets G can be conveyed in the longitudinal direction of the furnace. In the so-called continuous tempering furnace, the glass plate moves through the furnace only once, and in the so-called oscillating tempering furnace, the glass plate moves back and forth in the furnace until the heating time is reached. In Figures 1 to 5, the arrow MD shows the direction of movement of the glass in the oscillating furnace.
    - The speed of movement of the glass sheet in the tempering furnace is typically 50-200 mm / s. In an oscillating furnace, the speed is reversed at time 0, from which the speed accelerates to the above value. From the tempering furnace, the glass plate is transferred to a tempering vessel, where it is strongly cooled by air jets. The sowing speed is typically 200 to 600 mm / s.
    Above the conveyor, preferably at a short distance, typically 5 to 20 cm, - preferably 7 to 13 cm, blow housings 6 are arranged, below which a so-called nozzle cover 6a is provided with blow openings 9 for blowing heated convection air towards the conveyor and in particular towards the conveyor. transportable glass plate G. Typically, the blow openings 9 are holes machined in the plate, = with a diameter of 5 to 15 mm. The tempering furnace 1 is provided with means 3-8 for circulating the convection air blown onto the glass plate G N 25. 7 The blow case 6 consists of a distribution part 3a into which air flows from the oven-wide distribution channels 5, and a blow part 3b with electrical resistors 8. In the blow case E, the distribution part 3a is connected to the blow part 3b by means of a perforated plate 10. The purpose of the perforated plate 10 is to even out the blow pressure differences between the different blow openings 9 in the blow housing. 3 30 - The blow openings 9 are on the glass-facing surface of the blow housing 6 in the nozzle cover NN 6a. The distribution ducts 5 are provided with recirculating air fans 4 located inside the furnace 1. The drive motor 7 of the recirculating air fan 4 is arranged outside the furnace 1. The furnace has one or more units described in Figure 1 in succession.
    Electric resistors 8 are arranged in the blow housings 6, through which the air supplied to the blow housing 6 heats up and thus flows hotter into the blow openings 9, from which the air is discharged as jets towards the glass plate G.
    Each separately adjustable electric resistor 8 has its own control sensor, which - preferably is fixed to the lower surface of the blow case, i.e. to the surface against the glass.
    The sensor can also be located slightly, preferably about 1 to 30 mm closer to the glass plate than the above-mentioned lower surface, or centrally in the blow opening of the blow housing part covered by one electric resistor, i.e. in the air jet.
    Preferably, the control sensor is a thermocouple.
    Each thermocouple can be given its own setpoint temperature and the electrical resistor its own so-called firing time. The tripping time determines the longest possible on-time of the electric resistor, i.e. the electric power supply time, during one adjustment period.
    The preferred length of the electric resistance adjustment period is 2 to 8 s.
    With a tripping time shorter than the control period, the average power with respect to the duration of the control period of the resistor can thus be limited.
    Different convection and radiant heating can be set for adjacent and successive blowing areas of the blowing field, both with the thermocouple setpoint and the tripping time.
    In addition, the tempering furnace is arranged in a matrix-like manner with blow nozzles 11, in the gaps between the blow housings 13. Compressed air is supplied to the blow nozzles via supply pipes 12. - In the figures, the x-direction is the direction of travel of the glass plate, for which the z-direction is the transverse horizontal direction.
    The Y direction is the vertical direction.
    Figure 3 shows a preferred embodiment of the device according to the invention.
    Figure 3 shows a bottom view of the blow housings 6. Here, each blow housing 6 is divided from its blow section 3b into successive housing parts, 6a of which have a> 25 nozzle cover of each housing part, and each successive housing part is mounted at an acute angle to the glass. x, whereby a stepped structure is formed, even if the housing parts are in the direction of travel of the glass relative to each other.
    The above-mentioned angle α is preferably 2 to 10 degrees, most preferably about 3 to 5 degrees.
    The housing parts a © can also be in straight rows without stepping, in which case the direction of the rows and the blow housing 6 Q 30 is at the above-mentioned angle with respect to the direction of movement x of the glass.
    In this case, one nozzle cover 6a can be the entire length of the blow housing 6, i.e. one blow housing has only one housing part N.
    Blow nozzles 11 are arranged in the matrix-like pattern between the blower housings 13. The blow nozzles 11 can be, for example, holes machined in the supply pipes 12 or separate nozzles attached to the supply pipes. The flow cross-sectional area of one blow nozzle is preferably 0.5 to 4 mm. The blow nozzles 11 are arranged in approximately longitudinal rows and widthwise rows of the furnace, which rows are spaced L2 apart, i.e. in the x-direction. Typically, the distance L2 is 50 to 500 mm and preferably 100 to 300 mm. In Fig. 3, the blow nozzles are arranged so that in the same row in the width direction of the furnace the blow nozzle 11 is only in every other gap 13, and the distance of the blow nozzles in the same longitudinal row of the furnace, i.e. in the same gap 13, becomes L2 * 2. In Fig. 3, the longitudinal blow nozzle rows of the furnace are in the width direction of the furnace, i.e. in the z-direction, at a distance W2 from each other on both sides of the same blow housing. In the embodiment according to the figure, the distance W2 varies slightly depending on which blow nozzles of the adjacent gaps 13 it is determined, because the blow-nozzle rows are not straight in the longitudinal direction of the furnace due to the staggering of the housing parts. Typically, the distance W2 is 20 to 250 mm and preferably 40 to 160 mm. Preferably, the distance W2 is greater than the width of the nozzle cover 6a and smaller than the nozzle cover division in the z-direction. The dimensions mentioned above for the blow nozzle rows and rows also apply to the placement of the individually adjustable blow nozzles in the oven.
    - In Fig. 3, the blow housings 6 are longitudinal to the oven. In this case, the width of the separately adjustable blowing zone of the convection air convection in the width direction W1 of the furnace is preferably and in Fig. 3 is the same as the width of the blower housing division in the furnace width, i.e. the width of the blowing housing and gap in the furnace width direction. Typically W1 is 30 to 300 mm and preferably 60 to 160 mm. The length L1 of the separately adjustable blowing zone of the recirculating air convection in the longitudinal direction of the furnace is typically 200 to 1500 mm and preferably 300 to 1000 mm. Preferably, and in Fig. 3, the length L1 is the same as the length of the housing part 3 in the longitudinal direction of the furnace.
    Figure 4 illustrates in more detail the size of the separately adjustable areas E of the convection blowing means of Figures 1 to 3. The area of one of the individually adjustable areas of action of the first convection blowing means on the glass surface is Alb, which is slightly wider in the z-direction than the width of the nozzle cover 6a. This is because the blowing NN jets act on the surface of the glass over a wider area than the surface of the nozzle cover, depending on their blowing distance to the glass. According to a preferred embodiment, the surface area of one separately adjustable area of action of the second convection blowing means on the glass surface A2b is oval in Fig. 4.
    The figure corresponds in mouth to a blow nozzle 11, the flow opening of which is slightly wider in the z-direction than in the x-direction.
    The figure does not show that at the point of impact of the blow nozzle on the surface of the glass - the effect is greatest and decreases sharply as it moves away from it.
    It is therefore impossible to unambiguously determine the exact size A2b of the area of influence of the blow nozzle 11, since it depends on the blow distance, i.e. the distance in the y-direction between the glass plate and the mouth of the blow nozzle, and on the convection level.
    Thus, the size C1i and C2 of the cells of the convection control matrices C1 and C2, i.e. the area of one separately adjustable area of action of the convection blowing means, is determined in the coverage areas A1 and A2. Coverage area A1 is the area of the heating area of the furnace or, more precisely, the heating area covered by the first convection blowing means in the furnace Altot divided by the number of separately adjustable electric resistors in the blower housings N1 within the area Altot, and coverage area A2 is covered by the second N2 within the area A2tot.
    In Fig. 4, the area Alb is about the same as the area A1, because the gaps 13 of the blow housings are narrow.
    When the separately adjustable areas consist of one housing part of the nozzle housing with its resistors and one blowing nozzle 11, the cover area A1 is W1 * A1 and the cover area A2 is 2 (W2 * L2) as indicated in Fig. 4. Preferably, the coverage area A1 is 200 to 1500 cm 2 and the coverage area A2 is 50 to 600 cm 2. Preferably, in one furnace, N1 is at least 80 and N2 is at least 160.
    According to the preferred embodiment illustrated in Figures 1 to 4, the second convection blowing means comprise supply pipes 12 through the furnace roof, adapted to O 25 - pass between longitudinally and substantially longitudinal, i.e. glass-moving N-blowing blowers at the end of the furnace. 11. - According to another preferred embodiment, the second convection blowing means comprise feed pipes 12 passing through the roof or side walls of the furnace, adapted to O 30 - pass through blowing housings blowing substantially to the width of the furnace, i.e. transverse to the glass surface. to the blow nozzles 11. Figure 5 illustrates such an embodiment.
    The figure does not show the supply pipes 12, which can be adapted to run as in Figures 1 and 2. Their passage through the side walls of the furnace is also a preferred solution, since the gaps 13 of the blow housings are in the z-direction.
    In the case of oven-wide blow housings, the blow-box spacings 13 can be set wider than the longitudinal blow housings of Fig. 3 (direction x) and can be flat and straight in the z-direction over the entire oven width (direction-z). This facilitates the fitting of the supply pipes to the furnace so that they do not impede the initial assembly and disassembly / assembly of the blower housing parts during maintenance, e.g. replacement of the electric resistors 8.
    Fig. 5 shows the corresponding dimensional markings as in Fig. 3. The above-mentioned preferred and typical values for the separately adjustable length L2 and width W2 of the second convection blowing means are also valid now, but the change in the direction of the blowing housings from the longitudinal width of the furnace to the first .
    Now the width W1 of the individually adjustable blowing zone of the convection convection is 50 to 500 mm and preferably 150 to 400 mm, and the length L1 of the individually adjustable blowing zone is typically 50 to 1200 mm and preferably 100 to 800 mm.
    In Fig. 5, the width W1 is the same as the length of the housing part in the width direction of the furnace.
    On the other hand, in this embodiment, the division into housing parts does not have that additional advantage.
    In Fig. 5, the dimensions Lia and L1b correspond to the lengths L1 in the longitudinal direction of the furnace, which can be separately adjusted by an electric heater.
    In the case of dimension Lia separately - the adjustable range includes only one blow box and in the case of dimension L1b two.
    Thus, the separately adjustable blowing zone, i.e. the coverage area A1, may comprise electrically connected electrical resistors in successive blowing housings or blowing housing parts in the direction of movement of the glass.
    On the other hand, the preferred values mentioned for the embodiment of the longitudinal nozzle housings of the furnace for the separately adjustable roof areas (A1, A2) and the numbers (N1 N and N2) of the first and second convection blowing means also apply in the embodiment of the blowing widths of the furnace, as well as the following solution.
    According to a preferred solution, the length of the individually adjustable blowing area L1 of the first convection blowing means in the direction of movement E of the glass is at most 1200 mm and comprises at least one electrical resistor in the blowing housing O 30. > Figure 6 schematically illustrates a device according to the invention.
    The tempering furnace comprises a detector 14 for reading information describing the loading of the glass N plates, which may be, for example, a camera describing the glass loading on the loading table or a dense glass movement.
    a transverse row of capacitive or optical sensors over which the glass loading passes as it enters the tempering furnace.
    The detector 14 sends its information, i.e. the information needed to resolve the dimensions of the glass loading shape, to a control device 15, which is, for example, a computer.
    The tempering furnace also comprises a device 18 for generating the information necessary for determining the positions of the glass panes in the furnace, which is, for example, a servomotor of the tempering furnace conveyor or a pulse sensor connected to the actuators in the conveyor.
    For example, the control of other convection blowing devices works as follows.
    The operator supplies the control device 15 with the keyboard 25 to the blow pressure and to the glass-plate-specific blow area to which the blow of the blow nozzles 11 is to be directed.
    The control device 15 can also select this information itself, e.g. based on the size of the glass plate.
    The adjustment setting defines a blowing pressure of, for example, 3 bar and a blowing range of the entire surface area of the glass plate, excluding 20 cm at the front and rear ends and 15 cm at both side edges.
    The control valve 16 is adjusted to the set value of the blowing pressure, i.e. it restricts the pressure of the compressed air source 21 to a supply pressure of 3 bar to the valve terminal 17.
    The compressed air source, i.e. the device for supplying pressurized air to the furnace from the outside, is preferably a compressed air compressor with an outlet overpressure of preferably 6-12 bar.
    The blowing pressure in the furnace, i.e. the pressure difference across the blowing nozzle, is preferably 0.5 to 4 bar.
    The glass loading moves to the oven.
    The valve terminal 17 has its own valve for each separately adjustable unit of the second convection blowing devices - the control matrix C2, i.e. the cell C2i.
    The valve is preferably a shut-off valve, i.e. only a valve with open and closed positions.
    The control device 15 controls the valves of the valve terminal using the information received from the detector 14 and the device 18 so that the setting of the blowing zone is realized as accurately as possible.
    Accuracy is limited by the width and length of the C2i cells, as well as how the glass plates are located - relative to the cells in the oven.
    The accuracy can be improved by shortening the above-mentioned dimensions of the cells.
    The accuracy of the widthwise profiling of convection glass is also improved by taking into account the locations of the N profiling lines in the placement of the side edges of the glass sheets when placed on the loading table.
    The control device may omit profiling and blow N onto the entire glass plate if sufficiently accurate computational profiling is not obtained on the glass plate. = 30 - The blown nozzle compressed air is cut off at the glass-free areas. x When the valve is open, compressed air flows along the supply pipe 12 to the blow nozzle io 11, from where it discharges towards the glass plate.
    Each cell C2i has its own supply pipe 12.> When the valves of the valve terminal are similar to the control valve 16, different blowing pressures can be set for different blowing zones.
    The air flow discharged from the blow nozzle - is related to the blow pressure.
    Thus, both the shut-off and the control valve control the mass flow of air discharged from the blow nozzles. The local heat flux g from the air to the glass plate is the product of the convective heat transfer coefficient and the temperature difference between the air (Tair) and the surface of the glass plate (Tglass), i.e. g = h (Tair-Tglass). As the mass flow increases, the rate of impact of the jet on the glass sheet increases, which increases the heat transfer coefficient h. The heat transfer to the glass sheet thus increases, i.e. the heating effect of the air jets on the glass sheet increases. Thus, the heating effect of the air jets discharged from the blow nozzles of the other convection blowing devices on the glass sheet is arranged to be controlled by a valve by adjusting the air flow supply to the blow nozzles.
    The control of the first convection blowing devices works, for example, as follows.
    The operator 25 uses the keypad to enter the set temperatures and / or trip times for all individually adjustable electrical resistors in the control matrix C1, i.e. cells C1i. For example, the operator can drop the cells on the side edges of the glass sheets to the setpoints of 680 ° C and keep the other cells at the setpoints of 700 ° C, and shorten the tripping times of the electrical resistors at the beginning and end of the oven by 50%. The glass loading moves to the oven. Each cell C1i has its own switch in the electrical cabinet 19 and an electrical power supply cable 23. The switch interrupts the electrical current supplied by the electrical network 22 to the electrical resistor. The control device 15 controls the switches in the electrical cabinet on the basis of the temperatures measured by the temperature sensors, the temperature setpoints and the tripping times. Several temperature sensor cables 24 are connected to one measuring card 20. The heating effect of the air jets of the first convection blowing devices on the glass plate increases because the electric resistance raises the air temperature of the jet, whereby the term (Tair-Tglass) increases. Raising the set temperature of the cell Cli increases the heat flow from the cell Cli to the glass plate, so that the electric current consumption of the cell's electrical resistor also increases. Thus, the set temperature and the trip time both affect the electric current supply of the electric resistor. Thus, the heating effect of the air jets discharged from the blow openings of the first convection 25 devices on the glass sheet is arranged to be adjustable by adjusting the supply of electric current to the electric heater.
    N Preferably, the shape of the blow nozzles 11 is such that the jet discharged from them is wider in the width direction of the furnace than in the direction of movement of the glass in the furnace. In this case, the convection produced on the surface of the glass is flattened in the width direction of the glass.
    N 3 One supply pipe can supply air to several blow nozzles when it is branched at the end S to a different blow nozzle or when one blow nozzle section has several blow nozzles. The separately adjustable blower of other convection blowing devices
    however, the blowing opening of the area preferably consists of a maximum of 2 blowing nozzles in order to make the blowing areas of suitable size in relation to the intensity of a single jet. The intensity of the individual jet discharged from the blow nozzle of the second convection blowing means must be sufficient for its heating effect to bring a clear addition to the heating effect of the first convection blowing means. To ensure this, the blowing distance to the glass must be short enough. Thus, it is advantageous to arrange the supply pipes of the blow nozzles to run between the blow housings so that the blow nozzles of the second convection blow devices are between the blow housings, i.e. farther from the glass . Even more preferably, the blow nozzles are at least so deep between the blow housings that their vertical distance to the glass plate is shorter than that of the perforated plate. Preferably, the blow nozzles are at a vertical distance of at most 150 mm from the surface of the glass. The invention described above is not limited to the embodiment shown, but can be modified in many different ways within the scope of the claims. For example, the blow housings may be either longitudinal, transverse or at any oblique angle to these directions. A pair of convection blowing devices according to the invention - can only blow glass on the upper or lower surface, or both sides can have their own pair of devices. The gas recycled and blown into the furnace can be more than just air. It can also be a mixture of air and other gas. The duct supplying air to the blow housings may differ from the description and may have a different number of fans. o S 25
    O <Q OF
    I Jami a 00 O OF
    LO o o OF
    权利要求:
    Claims (13)
    [1]
    A glass sheet tempering furnace having a glass plate conveyor, first convection blowing means for heating the glass sheet with at least one surface to be blown by hot air jets, the first convection blowing means comprising a blower for blowing air drawn from the tempering furnace, air ducts, air ducts having blown openings (9) on the surface facing the glass plate from which air is discharged as jets towards the glass plate, electric heating elements (8) heating the air inside the blower housings, and other convection blowing means, - for conveying compressed air outside the tempering furnace to the blowing nozzles of which the air is sprayed towards the same surface of the glass plate as the air jets of the first convection blowing means, characterized in that the electric resistors and blowing housings of the first convection blowing devices form a plurality of separately adjustable blowing zones along the tempering furnace. in the new and width directions, in which the heating effect of the air jets on the glass sheet is arranged to be controlled by adjusting the electric power supply to the electric resistors, and the blow nozzles (11) of the second convection blowing means of the tempering furnace form a plurality of individually adjustable blowing the heating effect of the air jets discharged from the blow nozzles (11) on the glass sheet is - arranged to be adjustable by adjusting the air flow supply to the blow nozzles.
    [2]
    Tempering furnace according to patent application 1, characterized in that the first adjustable blowing zones of the first convection blowing means have a division of less than 1500 mm in the direction of movement of the glass and up to 300 mm in the transverse direction of movement of the glass, and the second convection blowing means have individually adjustable blowing zones. is at intervals of not more than 500 mm in the direction of movement of the glass and at intervals of not more than 250 mm N in the direction of transverse movement of the glass.
    [3]
    O Tempering furnace according to patent application 1, characterized in that the first adjustable blow ranges of the first convection blowing means have a division of less than 1000 E mm in the direction of movement of the glass and up to 160 mm in the transverse direction of movement of the glass, and separately adjustable blowing means of the second convection blowing means. - There are 3 slots at intervals of not more than 300 mm in the direction of movement of the glass and at intervals of not more than 160 mm N in the direction of movement of the glass.
    [4]
    Tempering furnace according to claim 1, characterized in that the first convection blowing means have at least 6 individually adjustable blowing areas in the width direction of the tempering furnace, and the second convection blowing means have at least 10 individually adjustable blowing areas in the width direction of the tempering furnace.
    [5]
    Tempering furnace according to patent application 1, characterized in that the first convection blowing means have at least 6 individually adjustable blowing areas in the longitudinal direction of the tempering furnace, and the second convection blowing means have at least 20 individually adjustable blowing areas in the longitudinal tempering furnace.
    [6]
    Tempering furnace according to claim 1, characterized in that the first convection blowing means have at least 80 individually adjustable blowing zones in the tempering furnace, and the second convection blowing means have at least 160 individually adjustable blowing zones in the tempering furnace.
    [7]
    Hardening furnace according to patent application 1, characterized in that one individually adjustable blowing area of the first convection blowing means covers a heating area of up to 1500 cm2 from the tempering furnace, and one individually adjustable blowing area of the second convection blowing means covers a maximum of 600 cm2. size heating surface tempering furnace.
    [8]
    Tempering furnace according to claim 1, characterized in that the supply pipes (12) of the blow nozzles (11) of the second convection blowing means are arranged to pass - between the blow housings (13) so that the blow nozzles are between the blower housings or closer to the glass plate. blowing openings for convection blowing means (9). o
    [9]
    Tempering furnace according to patent application 8, characterized in that the blowing parts (3b) of the blowing rollers are mounted at an acute angle to the direction of travel of the glass at an angle of 2 to 10 degrees, and air is fed to the blowing nozzles (11). = with supply pipes (12) passing through the roof of the su furnace and between the blower housings. E
    [10]
    Tempering furnace according to patent application 8, characterized in that the blowing housings (6) are substantially in the width of the furnace and the second convection blowing means N comprise supply pipes (12) passing through the roof or side wall of the tempering furnace, which are adapted to pass which end in the blower nozzles (11).
    [11]
    Tempering furnace according to patent application 1, characterized in that the shape of the blow nozzles (11) is such that the jet discharged from them is wider in the width direction of the tempering furnace than in the movement direction of the glass in the furnace.
    [12]
    Tempering furnace according to patent application 1, characterized in that the blowing opening of the separately adjustable blowing area of the second convection blowing means consists of at most 2 blowing nozzles (11).
    [13]
    Tempering furnace according to claim 1, characterized in that it comprises a detector (14) for generating information necessary for determining the dimensions of the glass loading shape, and a device (18) for generating information for determining the current position of the glass sheet in the tempering furnace, and control devices for controlling the valves of the second convection blowing means based on the dimensions of the glass loading shape and the position of the glass sheet. o
    O
    OF
    O <Q
    OF
    I Jami o 00
    O
    OF
    LO o
    O
    OF
    类似技术:
    公开号 | 公开日 | 专利标题
    EP2343266B2|2017-09-06|Method and apparatus for supporting and heating glass sheets on a hot gas cushion
    FI106256B|2000-12-29|Method and apparatus for directing the heating in a curing oven for glass sheets
    US7290405B2|2007-11-06|Method and apparatus for conducting heat to a glass sheet
    US10814367B2|2020-10-27|Method for the homogeneous non-contact temperature control of non-endless surfaces which are to be temperature-controlled, and device therefor
    JP2010163634A|2010-07-29|Apparatus for treating strip material
    KR101122810B1|2012-03-21|Convection heating furnace for a tempered glass sheet
    FI126763B|2017-05-15|Method and apparatus for curing glass sheets
    EP2805926B1|2016-12-21|Glass tempering furnace and method for heating glass sheets
    FI100596B|1998-01-15|Method and apparatus for heating glass sheets in a roll curing oven
    FI128655B|2020-09-30|Tempering furnace for glass sheets
    US7216511B2|2007-05-15|Furnace apparatus and method for tempering low emissivity glass
    FI114697B|2004-12-15|Method for Detecting Glass and Adjusting Heating Power in a Flat Glass Tempering Furnace
    JP4620327B2|2011-01-26|Apparatus and combined spray unit for spraying fluid onto at least the surface of a thin element
    FI20195604A1|2021-01-04|Tempering furnace for glass sheets
    FI20215179A1|2021-02-19|Tempering furnace for glass sheets
    US10000408B2|2018-06-19|Method for heating glass sheet, and glass tempering furnace
    US9422183B2|2016-08-23|Glass tempering furnace
    FI111006B|2003-05-15|Heat conducting method of glass sheet, involves blowing air sucked for suction chamber into pressure chamber from which air flows on glass
    FI128064B|2019-08-30|Method for tempering glass sheets
    CN111601777A|2020-08-28|Apparatus for annealing glass sheets
    同族专利:
    公开号 | 公开日
    TW202100478A|2021-01-01|
    EP3941883A1|2022-01-26|
    CN113614041A|2021-11-05|
    FI128655B|2020-09-30|
    WO2020188147A1|2020-09-24|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE19728787C1|1997-07-05|1998-09-03|Glafurit Anlagenbau Gmbh|Roller hearth furnace for glass sheet heating|
    FI120036B|2007-11-08|2009-06-15|Uniglass Engineering Oy|Method for heating a glass plate and the method applying device|
    FI20105257A|2010-03-15|2011-09-16|Glaston Services Ltd Oy|Device for heating glass sheets for curing|
    FI20120163A|2012-05-18|2013-11-25|Feracitas Oy|Heating method in tempering furnace|
    FI127228B|2013-05-23|2018-02-15|Taifin Glass Machinery Oy|Method for heating glass sheets and glass tempering furnace|FI20195604A1|2019-07-03|2021-01-04|Glaston Finland Oy|Tempering furnace for glass sheets|
    法律状态:
    2020-09-30| FG| Patent granted|Ref document number: 128655 Country of ref document: FI Kind code of ref document: B |
    优先权:
    申请号 | 申请日 | 专利标题
    FI20195208A|FI128655B|2019-03-21|2019-03-21|Tempering furnace for glass sheets|FI20195208A| FI128655B|2019-03-21|2019-03-21|Tempering furnace for glass sheets|
    CN202080023290.5A| CN113614041A|2019-03-21|2020-03-18|Tempering furnace for glass plate|
    PCT/FI2020/050168| WO2020188147A1|2019-03-21|2020-03-18|Tempering furnace for glass sheets|
    EP20773742.0A| EP3941883A1|2019-03-21|2020-03-18|Tempering furnace for glass sheets|
    TW109108961A| TW202100478A|2019-03-21|2020-03-18|Tempering furnace for glass sheets|
    [返回顶部]