JP2009210169A - Plate material holding device and heat treating method of plate material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plate material holding device and a method of uniformly heating a plate material capable of uniformly heating a plate material by a forced circulation type heating furnace. <P>SOLUTION: This plate material holding device for holding the plurality of plate materials 1 in parallel with each other in the heating furnace for forcibly circulating hot air to heat the plate materials 1 by allowing the hot air to pass between the plate materials includes a plurality of windbreak members 7 covering end faces at an upstream side in the hot air flowing direction of the plate materials at intervals, and shielding plates 10 extending from the windbreak members for covering an upstream side of one face of the plate material with a clearance. Furthermore, the windbreak members have holding tools for holding the plate materials. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a plate material holding device for heat treatment and a heat treatment method for a plate material.

  As described in Patent Documents 1 and 2, for example, in the manufacture of a flat display panel, in order to heat a plate material such as a glass substrate in a forced circulation heating furnace, a plurality of plate materials are flown in a hot air flow direction ( In general, a holding device is used that holds them in parallel with a gap therebetween.

  The heat exchange in the forced circulation furnace is turbulent heat transfer as represented by the Johnson-Rubesin equation. In turbulent heat transfer, the temperature rise on the upstream side of the hot air is much larger than the temperature rise on the downstream side. For this reason, the conventional heat treatment method has a problem that the temperature on the upstream side of the plate material becomes high and the plate material cannot be heated uniformly.

In patent document 2, although the invention which raises the heating efficiency of a downstream is described by arrange | positioning the radiation board facing the downstream of a board | plate material, the point which the temperature of the front-end | tip part of a board | plate material becomes high is fully improved. It has not reached.
JP 2005-114284 A JP 2007-225233 A

  In view of the above problems, an object of the present invention is to provide a plate material holding device capable of uniformly heating a plate material in a forced circulation heating furnace and a method for heating a uniform plate material.

  In order to solve the above problems, according to the present invention, a plurality of plate members are held in parallel in a heating furnace for forcedly circulating hot air, and the hot air is inserted between the plate members to heat the plate members. The plate material holding device includes a plurality of windproof members that cover the upstream end surface of the plate material in the hot air flow direction with a gap therebetween, and extends from the windbreak member, and covers the upstream side of one side of the plate material with a gap. It shall have a shielding plate.

  According to this configuration, the windproof member and the shielding plate block the hot air so that the hot air does not hit one surface on the upstream side of the plate material. Thereby, since the upstream part of a board | plate material becomes single-sided heating and a temperature rise is suppressed, the variation in the temperature rise by the part of a board | plate material can be reduced. Moreover, it can prevent that a heat | fever conducts to a board | plate material from a wind-proof member and a shielding board by making a clearance gap between a wind-proof member and a shielding board, and a board | plate material.

  Moreover, the board | plate material holding | maintenance apparatus of this invention WHEREIN: The said wind-proof member may have a holder for hold | maintaining the said board | plate material.

  According to this configuration, since the windproof member also serves as a structure that supports the holder, the configuration is not complicated.

  In the plate material holding device of the present invention, the windproof member has a rear edge portion on the side opposite to the shielding plate, the plate of the plate material having a distance of 1/2 or more of the distance in the hot air flow direction from the end surface of the plate material. It may protrude from the surface.

  According to this configuration, it is possible to prevent the hot air from flowing into the shielding member side of the plate material from the gap between the windproof member and the plate material and heating the plate material from both sides.

  In the plate material holding device of the present invention, the shielding plate may be made of a material having a low emissivity, preferably crystallized glass or other ceramic material.

  According to this configuration, even when the shielding plate reaches a high temperature, the plate material is not heated by radiation, and the temperature rise on the upstream side of the plate material can be reduced.

  The plate material heating method according to the present invention is a plate heat treatment method in which a plurality of plate materials are held in parallel, and hot air is inserted into the gaps between the plate materials to heat-treat the plate material, upstream of the hot air of the plate material. A wind-proof member that covers each of the end surfaces on the side and a shielding plate that extends from the wind-proof member so as to cover the upstream side of one side of the plate member.

  According to the present invention, hot wind directly hits one side of the upstream side of the plate by the wind-proof member that covers the upstream end of the plate and the shielding plate that extends from the wind-proof member and covers the upstream side of the plate. The heat transfer on the upstream side where the hot air temperature is high can be prevented and the plate material can be heated uniformly.

Embodiments of the present invention will now be described with reference to the drawings.
In FIG. 1, one embodiment of the heating method of the board | plate material of this invention is shown. In the present embodiment, for example, a glass substrate 1 for a plasma display panel is heat-treated in a heating furnace 2 as a plate material to be processed. The heating furnace 2 is a known roller hearth type continuous firing furnace, in which a roller conveyor 4 is provided inside a furnace body 3 made of a heat insulating material, and the holding device 5 holding the glass substrate 1 is successively heated by the roller conveyor 4. The glass substrate 1 is continuously fired (heated) by passing through the furnace 2.

  The holding device 5, which itself is one embodiment of the present invention, is configured to hold a plurality of glass substrates 1 vertically and hold them at a predetermined interval. The holding device 5 includes a frame 6, a windproof member 7 hung over the frame 6, an upper holding member 8 provided on the windproof member 7, a lower holding member 9 provided on the lower part of the frame 6, And a shielding plate 10 suspended from the windbreak member 7. The glass substrate 1 is held at the upper and lower ends by the upper holding member 8 and the lower holding member 9, the upper end is covered by the windproof member 7, and the upper part of the plate surface on one side is covered by the shielding plate 10 continuous from the windproof member 7. ing.

  The heating furnace 2 is provided with a hot air blowing port 11 above the holding device 5, hot air blows downward as indicated by an arrow, passes through the gap between the glass substrate 1 and the shielding plate 10, and is below the roller conveyor 4. It is designed to blow straight down to the side. The hot air blown down is reheated by a heater (heat source) 12 disposed on the lower side of the roller conveyor 4, and is heated by a fan 13 through a circulation channel 14 provided on the side in the furnace body 3. 2 and is blown down from the outlet 11 again through the filter 15.

  FIG. 2 shows details of the holding device 5. The windproof member 7 is made of C-type steel, and is attached to the lower surface of the upper member 6a of the frame 6 so that the lower side is opened. The upper holding member 8 is attached to the inside of the windproof member 7 and has a concave shape in which the lower end receives the glass panel 1. The lower holding member 9 is attached to the upper surface of the lower member 6 b of the frame 6, and the upper end has a concave shape for receiving the glass panel 1.

  The shielding plate 10 is, for example, a heat-resistant crystallized glass plate having a low emissivity and colored in white so as not to transmit heat rays, preferably having a specific heat comparable to that of the glass substrate 1 and having a thickness of about 3 mm. It consists of a board | substrate etc. of another ceramic type material, and the upper end is being fixed to the wind-proof member 7 with the screw, for example.

  FIG. 3 shows a temperature distribution when the windproof member 7 and the shielding plate 10 are arranged and the glass substrate 1 is heated in the heating furnace 2. In the vicinity of the upper end of the glass substrate 1, since one side is covered with the shielding plate 10, hot air hits only one side. For this reason, the amount of heat transferred from the hot air to the upper end portion of the glass substrate 1 is substantially halved compared to the case where the windproof member 7 and the shielding plate 10 are not provided, and the temperature distribution is as shown by the solid line in the figure, The temperature of the portion covered with the shielding plate 10 is lower than the temperature distribution in the case where the windproof member 7 and the shielding plate 10 shown by the broken line are not provided.

  According to the Johnson-Rubesin equation, the heat transfer rate from the hot air to the glass substrate 1 is inversely proportional to the 0.2th power of the distance from the upper end of the glass substrate 1. According to this, when the windproof member 7 and the shielding plate 10 are not provided, if the conditions of the glass substrate 1 and the heating furnace 2 are general, the temperature at a position of about 100 to 300 mm from the upper end of the glass substrate 1 is the upper end. It becomes the temperature of 1/2 of this temperature. Since the heat transfer amount in the upstream portion can be reduced by half by arranging the windproof member 7 and the shielding plate 10, the shielding plate 10 may cover the range of about 100 to 300 mm from the upper end of the glass substrate 1.

  When the wind-proof member 7 and the shielding plate 10 are in direct contact with the glass substrate 1, the glass substrate 1 is heated by heat conduction, so that a gap is left between the wind-proof member 7 and the shielding plate 10 and the glass substrate 1. There is a need. Moreover, the wind-proof member 7 and the shielding plate 10 heated with hot air can indirectly heat the glass substrate 1 by radiation. Therefore, it is desirable that the windproof member 7 and the shielding plate 10 have the same heat capacity as that of the glass substrate 1 so that the temperature does not rise extremely quickly as compared with the glass substrate 1, and is further formed of a material having a low emissivity. Or it is desirable to color so that an emissivity may become low. In particular, the shielding plate 10 facing the glass substrate 1 is easy to heat the glass substrate 1 by radiation.

  Further, when the gap between the windproof member 7 and the upper end of the glass substrate 1 is increased, the hot air circulates to the rear side of the windproof member 7, and the gap between the glass substrate 1 and the shielding plate 10 from the gap between the windproof member 7 and the glass substrate 1. Blow through. Then, the glass substrate 1 will be heated from both surfaces, and the effect of the wind-proof member 7 and the shielding board 10 will become small. In order to prevent such hot air from wrapping around, as shown in FIG. 4, the rear edge of the windbreak member 7 on the side opposite to the shielding plate 10 is in the normal direction (horizontal direction) from the plate surface of the glass substrate 1 to the plate surface. The distance H projecting in the direction (direction) is made to project more than ½ of the vertical distance (distance in the direction of hot air flow) V between the rear edge of the windbreak member 7 opposite to the shielding plate 10 and the upper end of the glass substrate 1. You can do it. It should be noted that if the width of the windbreak member 7 is excessively widened, the flow path of the hot air becomes narrow and the efficiency is lowered.

  Furthermore, as shown in FIG. 5, the present invention can reduce the difference in the temperature increase rate depending on the position of the glass substrate 1 by using it together with the radiation plate 16 that promotes the temperature increase on the downstream side of the glass substrate 1. it can. The radiation plate 16 preferably has a small heat capacity and a high radiation rate, such as a stainless steel foil having an oxide film formed on the surface thereof.

Sectional drawing of the heating furnace which concerns on the heat processing of the glass substrate of embodiment of this invention. The fragmentary sectional view of the board | plate material holding | maintenance apparatus of FIG. The figure which shows the temperature distribution of the glass substrate in the heat processing of FIG. The figure which shows the positional relationship of the glass substrate 1 and windproof member 7 by this invention. The figure which shows the temperature distribution of the glass substrate at the time of using a radiation plate together in the heat processing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Glass substrate 2 ... Heating furnace 5 ... Plate material holding device 6 ... Frame 7 ... Windproof member 8 ... Upper holding member 9 ... Lower holding member 10 ... Shielding plate

Claims (6)

A plate material holding device for holding a plurality of plate materials in parallel in a heating furnace for forcedly circulating hot air, and heating the plate material by inserting the hot air between the plate materials,
A plurality of windproof members that cover the end surface of the plate material on the upstream side in the flow direction of the hot air with a gap therebetween, and
A plate material holding device, comprising: a shielding plate extending from the windproof member and covering the upstream side of one surface of the plate material with a gap.   The plate material holding device according to claim 1, wherein the windproof member has a holding tool for holding the plate material.   The windbreak member is characterized in that a rear edge portion on the opposite side to the shielding plate protrudes from the plate surface of the plate material by ½ or more of the distance in the hot air flow direction from the end surface of the plate material. The board | plate material holding | maintenance apparatus of Claim 1 or 2.   The plate material holding device according to claim 1, wherein the shielding plate is made of a material having a low emissivity.   The plate material holding device according to any one of claims 1 to 3, wherein the shielding plate is made of crystallized glass. In a heat treatment method for a plate material that holds a plurality of plate materials in parallel and heat-treats the plate material by inserting hot air into the gap between the plate materials,
A heat-treating method for a plate material, comprising: a wind-proof member that covers an upstream end surface of the hot air of the plate material; and a shielding plate that extends from the wind-proof member so as to cover an upstream side of one surface of the plate material.

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