FR2501666A1 - METHOD AND DEVICE FOR CONTINUOUSLY TEMPERING GLASS PLATES - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS AND A DEVICE FOR CONTINUOUS TEMPERING OF GLASS PLATES COMING OUT OF A HEATING OVEN. THE DEVICE IS CHARACTERIZED IN THAT IT IS PROVIDED ON THE UPPER SIDE AND ON THE LOWER SIDE OF THE GLASS PLATES 7 RESPECTIVELY A PAIR OF INLET NOZZLES 1, 1A AND OUTLET NOZZLES 2, 2A FOLLOWING IN THE DIRECTION OF DISPLACEMENT OF THE GLASS PLATES 7 AND WHICH ARE ORIENTED PERPENDICULAR TO THE DIRECTION OF TRAVEL BY EXTENDING THE ENTIRE WIDTH OF THE GLASS PLATES 7 AND IN THAT EACH INPUT NOZZLE 1, 1A IS SEPARATED FROM THE ASSOCIATED OUTPUT NOZZLE 2 , 2A, CONSIDERING THE DIRECTION OF MOVEMENT OF THE GLASS PLATES, THROUGH A RETAINING CORNER 3, 3A EXTENDING CLOSE TO THE GLASS PLATES.

Description

The present invention relates to a method and a quenching device

  continuous glass plates heated in an oven, the upper face and the lower face of the glass plates driven horizontally by means of transport rollers being subjected to the action of a cooling agent.

  It is known to heat glass plates, especially

  of silicate and soda-lime glass in horizontal furnaces

  in a subsequent operation, quenching in cooling chambers, which are subjected in a known manner to oscillation, so as to obtain on both sides of the glass plates a central constraint of

  traction having the necessary value. As a coolant

  most of the time, air is used.

  This is brought in a substantially uniform manner on

  the two main faces of the glass plates.

  The essential disadvantage of the known processes is that the cooling air is sprayed by numerous nozzles on all the main faces of the glass. The relative spacing of the nozzles, which are generally arranged in a network,

  amounts to about 3 to 5 cm. The cooling air is pro-

  thrown with high pressure and high flow on the main faces of the glass plates, so that the air jet

  spring on the peripheral side surfaces of the plates.

  Cooling air is channeled from oversized air compressors, typically radial fans, into the cooling chambers. To achieve a heat transfer coefficient that is efficient by

  compared to glass, air compressors of one

  about 800 to 900 kW when quenching a glass plate with a cooling

  for example, dimensions of 300 x 200 cm.

  Not only is the high energy consumption a disadvantage of these known methods, but it is also necessary to provide very large and very expensive structures when

  the manufacture of the cooling boxes and compresses

  air sources. Thus, for example, in the known processes, there is a characteristic problem during cooling

  of glass plates having a thickness of 2 to 3 mm.

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  The cooling box of the surface of the plate

  the glass which is directed downwards is interrupted by

  carriers that have to be disposed of at a low level

  distance from each other between the cooling nozzles.

  However, the air flow from the cooling nozzles to the lower main face of the glass plate can only shower the surface which is placed

between the rollers.

  The invention must make it possible to find a solution for the

  problem of passing glass plates,

  thin layers, for example having a thickness of between 2 and 6 mm, which have been heated in an oven until they are

  almost reach their softening point (generally

  between 600 and 700 ° C) between cooling nozzles

  by means of which a cooling gas, usually air, is projected onto the two main faces of the glass plates without the nozzles being placed

  in the cooling boxes.

  To solve this problem, it is proposed according to the present invention, a method of the type defined above, which is characterized in that the glass plates are guided through two jets of a cooling agent directed from opposite sides towards the glass plates and extending

  over the entire width of said plates.

  The two jets are preferably deflected, immediately before reaching the glass plate, in the direction of movement of the latter and, after contact with the surfaces of the glass plate which is established for a determined time in a channel flow, they are evacuated again

by suction.

  The proposed mechanism for the implementation of this

  assigned is characterized in that on the upper side

  on the lower side of the glass plates, respectively

  a pair of inlet nozzles and outlet nozzles succeeding one another in the direction of movement of the glass plates and which extend over the entire width of said plates, and in that each inlet nozzle is separated from the nozzle associated exit, in the direction of travel, by a corner of

  restraint extending to near the glass plates.

  In an advantageous embodiment of the invention, the end of each retaining wedge which is directed towards the glass plate is T-shaped, so as to create a flow channel between the T-shaped ends. retaining wedges and the upper or lower side of the corresponding glass plates, this channel extending, considering the direction of movement of the plates of

  glass, from the inlet nozzle to the outlet nozzle.

  To modify the height of the retaining channel, the retaining wedges are movable perpendicularly to the retaining plates.

  guided glass between said retaining corners.

  The inlet and outlet nozzles which are provided on the

  the upper sides of the glass plates are preferably adjusted

  height by means of a maneuvering device.

  For the regulation of the flow velocity and the coolant flow, it is advantageously provided in

  the input nozzles of the control modulators.

  The inlet nozzles are preferably supplied with cooling gas via an air compressor

and a gas holding chamber.

  Because of the heating of the coolant and the resulting expansion. the outlet nozzles are

  preferably a little larger than the inlet nozzles.

  The power of the air compressors used with the

  device according to the invention for causing air to reach the

  Nozzle cooling can be reduced by 70% compared to

  the power of the air compressors used in the

known drugs.

  The proposed process requires only minimal flow

  of cooling gas, so that the cooling device

  dissement occupies only a small volume compared to

  bulky and expensive cooling chambers

known.

  Other advantages and characteristics of the invention

  will be highlighted, in the following description, given

  by way of non-limiting example, with reference to the drawings

nexes in which: -

4 2501666

  FIG. 1 is a schematic vertical longitudinal section

  than the device according to the invention; FIG. 2 shows details of a tuning modulator

  used for the regulation of the air flow.

  In FIG. 1, there is shown a glass plate 7 emerging by sliding a horizontal opening interval of a

  heating furnace 9, this plate having been subjected in a manner con-

  in the oven 9 to a sufficient heating to be able to

  reach a temperature corresponding to the softening point

  1 of the glass plate. The glass plate 7 is then

  subjected, after the heat treatment, to a process of

  cooling in accordance with the present invention, that is to say not involving, as in the known embodiments, cooling nozzles which are arranged in fairly large numbers in the form of networks, but using two cooling nozzles which are arranged perpendicularly to the transport path and which do not act on the entire surface but only on each zone of the glass plate 7 which is

  in the course of the displacement process, in correspondence with

  dance with the cooling nozzles for a short and continuous time interval. Thus, the heated glass plate 7 coming out of the oven 9 is driven via the conveyor rollers 12 directly between the cooling nozzles

  1, 2, la, 2a, placed immediately after the exit of the oven.

  A sensor 13 placed at the outlet of the oven detects the thickness

  and the width of a glass plate 7, and produces, via a generator not shown, electrical signals corresponding to the characteristic values of the glass plate and which are applied to a microprocessor,

not shown.

  This microprocessor controls an electric motor of

  10b that moves up or down, through a transmission mechanism 10, a protective wall It

  in correspondence to the thickness of the glass plate 7.

  When manufacturing a glass plate having, for example, a thickness of 3 mm and a central tensile stress of between 220 and 370 kg / cm 2, provision is made according to another characteristic of the invention,

  that the glass plate 7 is gripped by tracing cylinders

  8, outside the cooling zone but

  immediately after the nozzles 1, 2, la, 2a, and is

  more or less quickly between the nozzles, depending on the thickness of the glass and the flow control of the agent of

  cooling in gaseous form, in order to achieve the coeffi-

  the most favorable heat transmission

  According to the invention, the glass plate 7 moves, in consideration of the aforementioned characteristics, at a greater or lesser speed depending on the thickness of the glass to be treated, between the traction cylinders 8, transport cylinders

  12 made of ceramic material being provided with driving devices

  freely movable in the transport direction and the glass plates 7 thus moved which can be accelerated

  by the traction cylinders 8, while the binding of

  between a glass plate 7 and the transport cylinders

  is also maintained at constant speed.

  Uniform cooling and a transmission coefficient

  Heat transfer adopted specifically is a function of the fact that the glass plate 7 is moved by the traction cylinders 8 between the cooling nozzles at the speed calculated for the thickness and the width of the glass plates. The traction cylinders 8 are provided with drive motors whose

  speed is adjusted electronically.

  The regulation is carried out using the microprocessor from the thickness and width coordinates of the glass plates 7 which are defined using the sensor 13 and which are

stored in memory.

  The low thermal conductivity of the glass plates 7 makes it possible to quench the two main faces of the glass plate, necessary for its hardening, using a gaseous cooling agent by operating continuously only in one zone. band-shaped cooling

  which is oriented perpendicular to the transport route.

  The representation of FIG. 1 highlights the treatment

  cooling of the glass plates. The nozzles 1, 1a are supplied with cooling gas via an air compressor, not shown, and provided for two nozzles, this compressor having a maximum power of 80 to 100 kW.

  and the air arriving via two rooms 4 and 4a.

  The cooling nozzles 1a, 2a remain invariant to near the lower side of the main faces of the glass plate 7. The nozzles 1, 2 are set to the correct spacing distance from the corresponding face of the plate

  of glass, in relation to the thickness of this plate 7,

  ie by an automatic control provided by the sensor 13 and the microprocessor, via an electric motor

  operating mechanism 6b associated with a transmission mechanism 6.

  The cooling treatment of the glass is carried out by a

  coordinated regulation provided by the microprocessor, which

  two retaining wedges 3, 3a so as to bring them to a corresponding spacing distance from the glass plate 7. These retaining wedges 3, 3a are movable towards the

  up and down between the nozzles 1, 2, 1a, 2a through

  of a geared motor group 4b. The geared motor group

  4b moves the retaining wedges, under the control of the micro-

  processor, so as to bring them, relative to the glass plate 7, at a spacing distance which is such that the remaining channel allows the flow on the corresponding face of the glass plate of a quantity of gas of cooling to establish the correct coefficient of heat transfer. The retaining wedges 3, 3a are characterized by the fact that they form, by their T-shaped ends, a flow channel in the zone of the main faces of the glass plate, the height of this channel being adjustable in correspond to the thickness of the glass plates and their speed. By controlling the flow rate and the velocity of the gaseous cooling agent, it is possible to establish the most favorable heat transfer coefficient for the main faces of the glass plate in a flow zone. band shape. The cooling gas flows in a channel which is placed perpendicular to the

  transport transport above and below the main faces

  of the glass plate so that the air arriving through the nozzles 1, flows into the channel defined by the retaining wedges 3, 3a passing over the main faces of the glass plate to then enter the outlet nozzles 2, 2a, thus flowing in the same direction as the direction of movement of the glass plates. It is thus possible

  to ensure a continuous quenching of the main faces of the

only glass.

  For the uniform cooling of the glass plates 7, it is also important to perform the dosing of the amount of cooling gas and the regulation of its speed at the outlet of the injection nozzles 1, la, this regulation being provided by an adjustment modulator 5, 5a

(see Fig. 2).

  This tuning modulator receives instructions from

  operation from the microprocessor so as to com-

order an engine 14.

  The electric actuating motor 14 causes a cam 18 to move radially as far as the walls 15 which are movable as a result of the provision of the articulations 21, of the modulator of

  regulation 5, in opposition to the force of a spring 17.

  From the stored coordinates concerning the width and

  the thickness of the glass plate to be cooled, the microproces-

  transmission to the electric drive motor 14, information about

  the cam direction 18 which causes the movable walls 15 of the adjustment modulator 5 to move, depending on the predetermined data, outwardly or inwardly in order to shrink or to widen the flow channel 6 and to act in correspondence on the flow velocity and the flow rate of

the coolant.

  According to another characteristic of the invention, the determination of the amount of gaseous cooling agent

  passing through the nozzles 1, the is carried out using a module

  regulator 5, 5a which is controlled by a processor and adjusts, where appropriate, the flow rate and the quantity

  gaseous cooling agent.

  The cooling nozzles 1, 1a provide the gaseous coolant in an amount such that the outlet nozzles 2, 2a, the passage section of which is increased by

  compared to that of nozzles 1, la, receive the cooling gas

  which has become heated in the flow channel and has increased in volume so that the flow velocity and the static pressure of the gas in the flow channel are maintained at the temperature which makes it possible to establish the coefficient

  of the most favorable heat transmission.

  The structure and shape of the nozzles 1, 1a, 2, 2a are chosen so that the cooling gas acts on the main faces of the glass plate only in the channel zone

  connecting the nozzles 1 - 2a, and that the ambient temperature to the ex-

  the interior of the nozzles is not influenced. For this purpose, as shown in the figures, the inlet nozzles have an outlet which is bent in correspondence to the direction of movement of the glass plates so as to guide the coolant into the flow channels provided between the glass plate 7

  and the retaining wedges 3, 3a. The outlet nozzles 2, 2a comprise

  also a form adapted to the conditions of receiving the flow.

Claims (10)

  1.- Process for the continuous quenching of hot glass plates   in which the glass plates are subjected to the action of a cooling medium on each side, characterized in that the glass plates are guided through two jets of a cooling agent directed from opposite sides on the glass plates and extending   over the entire width of said plates.   2. A process according to claim 1, characterized in that the two jets are deflected immediately before reaching the glass plate in the direction of movement of the latter and are again evacuated by suction after a determined contact time with the surfaces of the plate glass in a flow channel.   3. Process according to claim 2, characterized in that   the height of the flow channel is changed in accordance with   dance to the thickness of the glass plates.   4.- Apparatus for continuous quenching of glass plates heated in an oven, in which the upper side and the lower side of the glass plates driven horizontally through conveyor rollers are subjected to the action of a cooling agent , characterized in that on the upper side and the lower side of the glass plates (7) a pair of inlet nozzles (1, la) and outlet nozzles (2, 2a) are following in the direction of movement of the glass plates (7) and   which are oriented perpendicular to the direction of movement   extending across the entire width of the glass plates (7) and in that each inlet nozzle (1, la) is separated from the associated outlet nozzle (2, 2a), considering the direction of movement glass plates, by a wedge   (3, 3a) extending to near the glass plates.   5.- Device according to claim 4, characterized in   what the end, oriented towards the glass plate correspon-   each of the retaining wedges (3, 3a) is T-shaped and that a flow channel is created between the T-shaped ends of the retaining wedges (3, 3a) and 2501 66   the upper face or the lower face of the glass plates, this channel ensuring each time the connection between a nozzle   inlet (1, la) and an outlet nozzle (2, 2a).   6. Device according to claim 5, characterized in that, for a modification of the height of the flow channel,   mentioned above, the retaining wedges (3, 3a) can be moved   perpendicular to the driven glass plates (7) between the retaining wedges (3, 3a).   7.- Device according to claim 2 or 3, characterized in that the outlet end of the inlet nozzles (1, la) and   the outlet end of the outlet nozzles (2, 2a) are   in the direction of the flow channel in order to establish   favorable flow conditions.   8.- Device according to any one of the claims   4 to 7, characterized in that the nozzles (1, 2) provided on the   the upper side of the glass plates (7) can be adjusted in   by means of an operating mechanism (6).   9.- Device according to any one of the claims   4 to 8, characterized in that it is provided in the nozzles -   input (1, la) of the regulating modulators (5, 5a) for controlling the flow rate and the flow rate of the cooling aqent.   10.- Device according to any one of the claims   4 to 9, characterized in that the flow outlet nozzles (2, 2a) are larger than the flow inlet nozzles (1, la).