JP3665283B2 - Heating method and heating apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for heating an object to be heated by a plurality of panel heaters arranged in parallel at intervals, and can be used for heating a flat panel display substrate, for example.
[0002]
[Prior art]
Conventionally, a heating device including a plurality of panel heaters arranged in parallel at intervals is heated between heating elements adjacent to each other so as to face the heating surface of the heater. It has been broken.
[0003]
[Problems to be solved by the invention]
In the heating region between the panel heaters adjacent to each other as described above, heat radiation is less near the center of the heating surface of the heater than near the periphery. Therefore, there exists a problem that the uniformity of the temperature distribution of each heating surface falls. Therefore, it is conceivable that the output of each heater is lower in the vicinity of the center of the heating surface than in the vicinity of the periphery. However, it takes time to adjust the heater output. Further, when the heating temperature is a relatively low temperature such as 250 ° C. or less, it is difficult to ensure sufficient uniformity of the temperature distribution even if the heater output is adjusted.
An object of this invention is to provide the heating method and heating apparatus which can solve the said problem.
[0004]
[Means for Solving the Problems]
In the method of the present invention, the gas flow provided in each heater is heated by the heating device of the present invention when heating the heating object disposed so as to face the heating surface of the heater between the heaters adjacent to each other. A gas having a temperature lower than the set temperature of the heater is introduced into the space, and the gas introduced into the gas flow space is caused to flow from the center to the periphery of the heating surface.
According to the method of the present invention, the gas having a temperature lower than the set temperature of the heater is caused to flow from the center to the periphery of the heating surface in the gas flow space provided in the heater, so that the heating of the heater in the arrangement region to be heated is performed. Heat dissipation near the center of the surface can be promoted. Thereby, the temperature distribution of the heating surface can be made uniform with high accuracy in a short time, and the object to be heated can be heated uniformly.
[0005]
The device of the present invention is a heating device including a plurality of panel-like heaters arranged in parallel at intervals, and a heating target is disposed between the heaters adjacent to each other so as to face the heating surface of the heater, A gas flow space is provided inside each heater, and gas introduction means for introducing gas into the gas flow space is provided. The gas introduced into the gas flow space flows from the center to the periphery of the heating surface. Thus, the gas is introduced near the center of the heating surface.
According to the apparatus of the present invention, the method of the present invention can be carried out. Furthermore, by providing a gas flow space in each heater, the weight can be reduced as compared to a solid heater.
[0006]
In the present invention apparatus, the gas introducing means, said has the outlet blowing out the gas from the vicinity of the center of the heating surface in the gas flow space, in each heater, the outlet of the gas introduced into the gas flow space , that provided at a position close to the periphery of the heating surface.
Thereby, the method of the present invention can be implemented at low cost without requiring a complicated configuration.
[0007]
In the apparatus of the present invention, each heater is provided with a partition that divides the gas flow space into a chamber near the center of the heating surface and a chamber closer to the periphery than the chamber near the center. It is preferable that a gas flow hole for connecting adjacent chambers is provided, and the gas is introduced into the chamber near the center of the heating surface by the gas introducing means.
Thereby, gas can be reliably made to flow toward the periphery from the center of a heating surface.
[0009]
In the present invention apparatus, the heater is disposed inside the furnace body having inlet and outlet of the heating target, the gas discharged from the discharge port, is that provided means for directing toward the doorway of the furnace body.
This prevents the outside air from entering the furnace body from the entrance / exit of the furnace body by the gas exhausted from the exhaust port to reduce the temperature drop inside the furnace body and prevent the furnace body temperature from becoming uneven. Energy saving.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
A heating device 1 shown in FIGS. 1 and 2 includes a furnace body 2 and a plurality of panel heaters 3 disposed inside the furnace body 2. The heaters 3 are juxtaposed at intervals along the vertical direction with the thickness direction being the vertical direction as shown in FIG. 3 so that the space can be used efficiently. The plate-like heating object 4 is arranged so as to face the heating surface constituted by the upper surface of the heater 3 between the heaters 3 adjacent to each other with the thickness direction being the vertical direction. The heating surface and the upper and lower surfaces of the heating object 4 are arranged along the horizontal. In the present embodiment, the heating object 4 is put in and out from the doorway opened and closed by the open / close doors 2a and 2b on both sides of the furnace body 2.
[0011]
As shown in FIG. 4, each heater 3 is supported by a furnace body 2 via a bracket 5. Each heater 3 includes a heater body 10 and a heater cover 11 that covers the lower side of the heater body 10. The heater body 10 is configured by sandwiching a heating element 10a that generates heat when energized between aluminum plates 10b and 10c, and its upper surface is a heating surface 3a. The heating target 4 is supported by the support piece 6 protruding from the heating surface 3a. The heater cover 11 is made of a stainless steel plate, and includes a bottom plate 11a and a peripheral wall 11b extending upward from the outer edge of the bottom plate 11a. The bottom surface of the bottom plate 11a is a reflective surface 11a 'having a metallic luster, and reflects the heat rays emitted from the heating surface 3a. Thereby, the heating object 4 is directly radiantly heated from below by the heater 3 and indirectly radiantly heated from above.
[0012]
A gas flow space 20 surrounded by the heater body 10 and the heater cover 11 is provided inside each heater 3. As shown in FIG. 5, the gas flow space 20 is divided by a partition wall 21 into a chamber 20a near the center of the heating surface 3a and a chamber 20b closer to the periphery than the chamber 20a near the center. The partition wall 21 is provided with a gas flow hole 21a that communicates adjacent chambers.
[0013]
A gas introduction pipe 22 is provided as a gas introduction means for introducing gas into the gas flow space 20 of each heater 3. One end of the gas introduction pipe 22 is connected to a gas supply source (not shown) outside the furnace body 2. The other end of the gas introduction pipe 22 is branched so as to be inserted into each heater 3, and is arranged in a chamber 20 a near the center of the heating surface 3 a in each gas flow space 20. Thereby, the other end of the gas introduction pipe 22 is a blowout port 22a through which gas is blown out from the vicinity of the center of the heating surface 3a in the gas flow space 20. The gas blown from the blowout port 22a is introduced into the chamber 20a in the vicinity of the center of the heating surface 3a, and then passes through the gas circulation hole 21a as shown by the arrow in FIG. 5 to approach the periphery of the heating surface 3a. Flow into the chamber 20b. That is, the gas introduced into the gas flow space 20 flows from the center of the heating surface 3a toward the periphery. In order to preheat the gas introduced into the gas flow space 20, a heater 26 for preheating the gas flowing through the gas introduction pipe 22 is attached to the furnace body 2 as shown in FIG.
[0014]
In order to discharge the gas introduced into the gas flow space 20, a plurality of discharge ports 23 are provided in the bottom plate 11 a of the heater cover 11 of each heater 3. Each outlet 23 is close to the periphery of the heating surface 3a. Each discharge port 23 is arranged at a position farther from the center of the heating surface 3a than the arrangement region of the heating target 4 so that the gas discharged from each discharge port 23 is not directly blown onto the heating target 4. . The number and arrangement of the discharge ports 23 are not particularly limited as long as the gas introduced into the gas flow space 20 can flow from the center of the heating surface 3a toward the periphery.
[0015]
In order to guide the gas discharged from the discharge port 23 to the outside of the furnace body 2, exhaust pipes 27 having a plurality of gas inflow holes 27 a formed on the outer periphery are provided on both sides of each heater 3. One end of each exhaust pipe 27 is closed, and the other ends are connected to each other and open outside the furnace body 2. In addition, the gas inflow hole 27a of each exhaust pipe 27 is formed at a position facing the entrance / exit of the furnace body 2, and thereby the gas discharged from the exhaust port 23 is guided toward the entrance / exit of the furnace body 2. Therefore, when the door of the furnace body 2 closed by the opening / closing doors 2a and 2b is opened, the outside air is prevented from entering the furnace body 2 from the door and the temperature in the furnace body 2 is suppressed. Reduction can be reduced.
[0016]
The type of the gas is not particularly limited as long as it does not affect the heating target 4, and for example, nitrogen gas or dry air can be used. The gas flow rate may be appropriately determined according to the scale of the heating device 1 and the set temperature of the heater 3. For example, when the dimensions of each heater 3 are 950 mm × 1140 mm × 38 mm, the parallel pitch is 75 mm to 90 mm, and five heating objects 4 are processed, the gas flow rate is 20 to 100 liters per minute for each heater. The temperature of the gas is preferably about 20 ° C. lower if the set temperature of the heater 3 is 100 ° C. to 180 ° C., for example, and about 30 ° C. lower if the set temperature of the heater 3 is 180 ° C. to 250 ° C. The present invention is not limited to this, and it is not always necessary to preheat the gas.
[0017]
According to the above-described embodiment, when the heating object 4 disposed so as to face the heating surface 3a is radiantly heated between the heaters 3 adjacent to each other, the gas flowing into the gas flow space 20 is lower in temperature than the set temperature of the heater. And the gas introduced into the gas flow space 20 flows from the center of the heating surface 3a toward the periphery. Thereby, in the arrangement | positioning area | region of the heating target 4, the thermal radiation in the center vicinity of the heating surface 3a can be accelerated | stimulated. Therefore, the temperature distribution of the heating surface 3a can be made uniform with high accuracy in a short time, and the heating object 4 can be heated uniformly. By providing the gas flow space 20 in each heater 3, the weight can be reduced as compared with a solid heater. Moreover, since it is only necessary to provide the gas outlet 22a in the vicinity of the center of the heating surface 3a and the gas outlet 23 in the vicinity of the periphery of the heating surface 3a, it is possible to carry out at a low cost without requiring a complicated configuration. Can do. In the gas flow space 20, the gas flows from the chamber 20a near the center of the heating surface 3a to the chamber 20b near the periphery through the gas flow hole 21a, so that the gas surely flows from the center of the heating surface 3a toward the periphery. be able to. Furthermore, since the gas discharged from the discharge port 23 is not directly blown onto the heating object 4, temperature fluctuations of the heating object 4 due to the gas can be prevented.
[0018]
【Example】
FIG. 6 shows changes over time in the temperature and temperature deviation of the glass substrate for flat panel display heated by the heating device 1 of the above embodiment. The dimensions of the glass substrate were 730 mm × 920 mm × 0.7 mm, the set temperature of the heater 3 was 230 ° C., and the gas flow rate was 30 liters per minute. In the figure, the horizontal axis represents the heating time, the left vertical axis represents the glass substrate surface temperature, and the right vertical axis represents the glass substrate surface temperature deviation. In the figure, the solid line A is the time change of the temperature of the maximum surface temperature position of the glass substrate, the solid line B is the time change of the temperature of the minimum surface temperature position of the glass substrate, and the broken line C is a deviation from the set temperature of the maximum surface temperature position of the glass substrate. , The broken line D represents the time variation of the deviation from the set temperature of the minimum surface temperature position of the glass substrate, and the broken line E represents the time variation of the deviation between the temperature of the maximum surface temperature position of the glass substrate and the temperature of the minimum surface temperature position. Show. Thereby, according to the heating apparatus 1 of the said embodiment, it has confirmed that the deviation of the maximum surface temperature and the minimum surface temperature could be 5 degrees C or less in about 6 minutes. On the other hand, when the gas is not supplied, the deviation does not become smaller than about 10 ° C. even when time elapses, and a very long time is required until the target deviation is reached. Sometimes it took. That is, according to the present invention, it was confirmed that the temperature distribution in the heating region can be made uniform in a short time and the heating object can be uniformly heated with high accuracy.
[0019]
【The invention's effect】
According to the present invention, the temperature distribution in the heating region between a plurality of panel heaters arranged in parallel can be made uniform in a short time with a low-cost and simple configuration, and the heating target can be uniformly heated with high accuracy. Further, it is possible to provide a heating method and a heating apparatus that can reduce the weight of each heater and save energy.
[Brief description of the drawings]
FIG. 1 is a side view of a heating apparatus according to an embodiment of the present invention. FIG. 2 is a plan view of the heating apparatus according to an embodiment of the present invention. FIG. 4 is a side cross-sectional view of the main part of the heating device according to the embodiment of the present invention. FIG. 5 is a plan cross-sectional view of the main part of the heating device of the embodiment of the present invention. Of time variation of temperature and temperature deviation of substrate heated by heat 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 1 Heating apparatus 2 Furnace body 3 Panel heater 3a Heating surface 4 Heating object 20 Gas flow space 20a Chamber 20b near the center of the heating surface Chamber 21 closer to the periphery than a chamber near the center of the heating surface Partition wall 21a Gas flow hole 22 Gas inlet piping 22a Outlet 23 Outlet

Claims (3)

A plurality of panel heaters arranged in parallel at intervals,
Between the heaters adjacent to each other, a heating device in which a heating target is arranged so as to face the heating surface of the heater,
A gas flow space is provided inside each heater,
Gas introducing means for introducing gas into the gas flow space is provided,
The gas introduction means has a blowout port for blowing out gas from the vicinity of the center of the heating surface in the gas flow space,
The gas is introduced near the center of the heating surface so that the gas introduced into the gas flow space flows from the center of the heating surface toward the periphery,
In each heater, a gas outlet introduced into the gas flow space is provided at a position close to the periphery of the heating surface,
The heater is arranged inside a furnace body having an entrance to be heated,
A heating device characterized in that means for guiding the gas discharged from the discharge port toward the doorway of the furnace body is provided. Each heater is provided with a partition that divides the gas flow space into a chamber near the center of the heating surface and a chamber closer to the periphery than the chamber near the center,
The partition wall is provided with a gas flow hole that communicates between adjacent chambers,
The heating apparatus according to claim 1, wherein gas is introduced into the chamber near the center of the heating surface by the gas introduction means . When heating a heating object arranged so as to face the heating surface of the heater between the heaters adjacent to each other by the heating device according to claim 1 or 2,
A gas having a temperature lower than the set temperature of the heater is introduced into the gas flow space provided in each heater, and the gas introduced into the gas flow space flows from the center of the heating surface toward the periphery. Heating method .

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