JP2008188521A - Heat treatment furnace for waste glass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat treatment furnace for waste glass which is enabled to lower the running cost and recover only a glass layer from the waste glass. <P>SOLUTION: The heat treatment furnace 1 for waste glass comprises a table 30 having a ventilating property and on which waste glass W consisting of glass layers W1 and W2 and a resin layer W3 containing a thermoplastic resin and joined to the glass layers W1 and W2 are placed, and a down stage chamber 22D installed under the table 30 and controlled at a temperature equal to the evaporation starting temperature of the thermoplastic resin or higher, and an upper stage chamber 22U installed above the table 30 and controlled at a temperature lower than the glass softening temperature of the glass layers W1 and W2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat treatment furnace for waste glass for removing a resin layer from waste glass such as a windshield of an automobile and collecting the glass.

  Laminated glass has a laminated structure composed of a pair of glass layers and a resin layer interposed between the pair of glass layers. The resin layer is made of an adhesive resin such as polyvinyl butyral (PVB). The resin layer and the glass layer are bonded together by thermocompression bonding. Since laminated glass has high strength, it is frequently used as safety glass such as a windshield of an automobile.

  When processing used laminated glass (hereinafter referred to as “waste laminated glass” as appropriate), the glass layer and the resin layer are firmly bonded to each other. Have difficulty. Therefore, conventionally, waste laminated glass has been landfilled in the ground.

  However, the glass layer hardly changes over time even in the ground. For this reason, landfill sites are becoming wider, and depending on landfill processing, there is a risk of environmental destruction. Moreover, in the case of a landfill process, a glass layer cannot be collect | recovered. For this reason, there is a problem from the viewpoint of resource protection. On the other hand, if the cost associated with the recovery of the glass layer is too high, the landfill treatment as before will result in lower costs. For this reason, the motivation with respect to collection | recovery of an industrial waste disposal contractor becomes weak.

In this regard, Patent Document 1 introduces a rotary kiln that can incinerate only a resin layer from waste laminated glass. The temperature of the rotary kiln is controlled below the glass softening temperature. In addition, the waste laminated glass moves in the axial direction while rotating around the axis of the kiln in the rotary kiln. For this reason, a shearing force is applied between the pair of glass layers of the waste laminated glass. According to the rotary kiln of Patent Document 1, the heat treatment temperature below the glass softening temperature and the shearing force applied between the glass layers can be combined to recover only the glass layer.
Japanese Patent Laid-Open No. 7-138053 JP 11-165150 A

  However, the resin layer is flammable. For this reason, the amount of heat generated during combustion is large. Therefore, if the temperature in the rotary kiln is not properly controlled, the heat treatment temperature may increase (runaway) and exceed the glass softening temperature. In this case, the glass layer may be softened or melted and cannot be reused.

  Therefore, Patent Document 2 discloses a temperature management method when heat-treating waste laminated glass. According to the temperature management method described in Patent Document 2, heat generation due to combustion of the resin layer is suppressed by driving nitrogen, which is an inert gas, into the furnace (see [0034] of Patent Document 2). However, Patent Document 2 does not disclose a specific configuration of a furnace that performs heat treatment. For this reason, the specific temperature management method in a furnace is unknown.

  The heat treatment furnace for waste glass of the present invention has been completed in view of the above problems. Accordingly, an object of the present invention is to provide a heat treatment furnace for waste glass that has a low running cost and can recover only a glass layer from waste glass.

  (1) In order to solve the above-mentioned problems, the waste glass heat treatment furnace of the present invention is provided with a waste glass formed by laminating a glass layer and a resin layer containing a thermoplastic resin bonded to the glass layer. A table having air permeability, a lower chamber disposed below the table and temperature-controlled at a temperature equal to or higher than an evaporation start temperature of the thermoplastic resin, and disposed above the table, the glass of the glass layer And an upper chamber whose temperature is controlled to be lower than the softening temperature (corresponding to claim 1). Here, the “evaporation start temperature” of the thermoplastic resin refers to a temperature at which evaporation starts when heating. Specifically, it refers to the temperature at which weight loss starts in the TG / DTA method.

  That is, the heat treatment furnace for waste glass of the present invention has a lower chamber disposed below and an upper chamber disposed above with a table having air permeability. The temperature of the lower chamber is controlled above the evaporation start temperature of the thermoplastic resin. For this reason, the thermoplastic resin in the resin layer of the waste glass placed on the table is evaporated by the heat of the lower chamber. The thermoplastic resin evaporates into a flammable vapor. The upper chamber is heated by burning at least part of the combustible vapor. The upper chamber is temperature controlled below the glass softening temperature.

  As described above, the heat treatment furnace for waste glass of the present invention heats the upper chamber by utilizing the combustion of the combustible evaporative gas. Further, temperature control in the furnace is performed by utilizing a temperature gradient in the furnace from the lower chamber (low temperature) to the upper chamber (high temperature). For this reason, running cost is low.

  The temperature of the lower chamber is controlled to be equal to or higher than the evaporation start temperature of the thermoplastic resin, and the temperature of the upper chamber is controlled to be lower than the glass softening temperature. For this reason, there is little possibility that a resin layer will remain in the glass layer after collection (after heat treatment). In addition, the glass layer after recovery is less likely to soften and melt. Therefore, the quality of the recovered glass layer is high.

  (2) Preferably, in the configuration of (1), further comprising a heat treatment zone having the lower chamber and the upper chamber, and a heating zone that is connected to the upstream side of the heat treatment zone and heats the waste glass, The table is a mesh belt of a mesh conveyor that conveys the waste glass from the heating zone to the heat treatment zone, and it is preferable that the waste glass is continuously heat treated (corresponding to claim 2).

  That is, this structure heats and heat-processes waste glass, conveying with a mesh conveyor. According to this structure, the glass layer in waste glass can be collect | recovered continuously.

  (3) Preferably, in the configuration of (2) above, the temperature increase rate of the waste glass in the heating zone is preferably higher than 50 ° C./min (corresponding to claim 3). According to this configuration, the temperature of the waste glass can be quickly raised before reaching the heat treatment zone. Here, the reason for setting the temperature rising rate to be over 50 ° C./min is that when it is 50 ° C./min or less, the glass layer is hard to crack. That is, the glass layer has a low thermal conductivity. For this reason, when the rate of temperature rise exceeds 50 ° C./min, the glass layer tends to crack. When a crack enters the glass layer, the combustible vapor can be released through the crack in the heat treatment zone. For this reason, it is difficult for the resin layer to remain in the recovered glass layer.

  (4) Preferably, in any one of the constitutions (1) to (3), a burner disposed in the lower chamber and for evaporating the thermoplastic resin into a combustible vapor, and the upper It is better to have an oxygen introduction pipe disposed in the chamber for burning at least a part of the combustible vaporized gas (corresponding to claim 4). According to this configuration, the thermoplastic resin can be evaporated relatively easily. Moreover, at least a part of the combustible vapor can be combusted.

  (5) Preferably, in the configuration according to any one of (1) to (4), a watering device that is further disposed in the upper chamber and suppresses the temperature of the upper chamber from being equal to or higher than the glass softening temperature. It is better to have a configuration (corresponding to claim 5). According to this configuration, it is possible to suppress the temperature of the upper chamber from being equal to or higher than the glass softening temperature relatively easily and reliably due to the latent heat of vaporization of water.

  (6) Preferably, in any one of the configurations (1) to (5), the thermoplastic resin is a polyvinyl butyral resin, and the temperature of the lower chamber is 400 ° C. or higher and 450 ° C. or lower. Is better (corresponding to claim 6).

  The evaporation start temperature of the PVB resin is, for example, about 280 ° C. in a nitrogen atmosphere and a temperature increase rate of 15 ° C./min. The temperature of the lower chamber of this configuration is controlled to be 400 ° C. or higher and 450 ° C. or lower, which is higher than 280 ° C.

  Here, the reason why the temperature is 400 ° C. or higher is that when the temperature is lower than 400 ° C., the PVB resin may remain in the recovered glass layer. On the other hand, the reason why the temperature is set to 450 ° C. or lower is that when the temperature exceeds 450 ° C., the amount of flammable evaporated gas increases, and the temperature of the upper chamber may be higher than the glass softening temperature.

  (7) Preferably, in the configuration of (6) above, the table is preferably made of a metal not containing nickel (corresponding to claim 7). As described above, when the temperature of the lower chamber is 400 ° C. or higher and 450 ° C. or lower, even if the material of the table (mesh belt of the mesh conveyor in the configuration of (2) above) is made of metal that does not contain nickel, It is fully usable. Therefore, the equipment cost can be reduced as compared with the case where the table is made of a nickel-containing metal for improving heat resistance.

  (8) Preferably, in the configuration of (6) or (7) above, a metal tray that is made of a metal that does not contain nickel and that collects the waste glass dropped from the table is laid. (Corresponding to claim 8).

  As described above, when the temperature of the lower chamber is controlled to be 400 ° C. or higher and 450 ° C. or lower, a metal collection tray not containing nickel can be laid in the furnace. For this reason, the waste glass dropped off from the table (the mesh belt of the mesh conveyor in the configuration of (2) above) can be recovered relatively easily. Moreover, compared with the case where a collection | recovery tray is made from a nickel containing metal, an installation cost can be reduced.

  (9) Preferably, in any one of the configurations (1) to (8), the upper chamber is preferably temperature-controlled to 650 ° C. or lower (corresponding to claim 9). According to this configuration, even if the combustion of the combustible evaporative gas suddenly becomes intense, the temperature of the upper chamber can be suppressed below the glass softening temperature. For this reason, the quality of the collected glass layer becomes high.

  (10) Preferably, in any one of the configurations (1) to (9), the waste glass is waste laminated glass in which a pair of glass layers are bonded via the resin layer, It is better to have a structure in which a crack reaching the resin layer from the outside is formed in the glass layer (corresponding to claim 10).

  According to this configuration, cracks are formed in the glass layer of the waste laminated glass. For this reason, combustible vaporized gas is easily released from the resin layer as compared with the case where the entire front and back surfaces of the resin layer are covered with the glass layer (when there is no crack). Therefore, the resin layer is unlikely to remain on the recovered glass layer.

  According to the present invention, it is possible to provide a heat treatment furnace for waste glass that has a low running cost and can recover only a glass layer from waste glass.

  Hereinafter, embodiments of the heat treatment furnace for waste glass of the present invention will be described.

<First embodiment>
(Overall configuration of heat treatment furnace for waste glass)
First, the whole structure of the heat treatment furnace for waste glass of this embodiment is demonstrated. In FIG. 1, the longitudinal direction sectional drawing of the heat processing furnace for waste glass of this embodiment is shown. As shown in FIG. 1, the waste glass heat treatment furnace 1 of this embodiment includes a furnace body 2, a mesh conveyor 3, an exhaust gas treatment facility 4, a pit 5, a burner (not shown), an oxygen introduction pipe (not shown), and a heat treatment. A zone lower chamber temperature controller (not shown), a heat treatment zone upper chamber temperature controller (not shown), and a heating zone temperature controller (not shown) are provided.

  The furnace body 2 includes a furnace wall 20 and legs 21. The furnace body 2 is divided into an upstream (rear) heating zone A and a downstream (front) heat treatment zone B. The furnace wall 20 has a long rectangular tube shape. The furnace wall 20 extends in the horizontal direction (front-rear direction). The top wall portion of the heat treatment zone B section in the furnace wall 20 is formed one step higher than the top wall section of the heating zone A section. The configuration of the heat treatment zone B and the heating zone A will be described in detail later. The legs 21 are made of steel, and a large number of legs 21 are arranged over the entire length of the furnace wall 20. The leg portion 21 supports the bottom wall portion of the furnace wall 20.

  The mesh conveyor 3 includes a mesh belt 30 and a roller 31. The mesh belt 30 is formed by braiding a wire made of SUS430 (martensite) into a mesh shape or a nonwoven fabric shape. The mesh belt 30 has air permeability. The rollers 31 are made of steel, and a large number of rollers 31 are arranged along the longitudinal direction of the furnace body 2. In addition, the roller arrange | positioned inside the furnace main body 2 is abbreviate | omitted and shown. A large number of rollers 31 stretch the mesh belt 30 in an endless belt shape. Specifically, the mesh belt 30 is stretched in two upper and lower stages, and the upper stage (outward path) passes through the furnace wall 20 from the rear to the front. On the other hand, the lower stage (return path) penetrates the bottom of the furnace wall 20 (between the leg portions 21) from the front to the rear. Among the many rollers 31, the mesh belt 30 is driven mainly by the roller 31 at the rear end.

  The exhaust gas treatment facility 4 includes an exhaust gas collecting pipe 40, an exhaust gas treatment furnace 41, a dust collector 42, a blower 43, and a discharge port 44. The exhaust gas collecting pipe 40 is made of steel and has a branched cylindrical shape. The branch end (upstream end) of the exhaust gas collecting pipe 40 is branched and connected to the top wall portion of the furnace wall 20. On the other hand, the merging end (downstream end) of the exhaust gas collecting pipe 40 is connected to the exhaust gas treatment furnace 41. The exhaust gas treatment furnace 41, the dust collector 42, the blower 43, and the discharge port 44 are connected in series in this order on the downstream side of the exhaust gas collecting pipe 40. The pit 5 is recessed in the ground G.

(Configuration of heat treatment zone)
Next, the structure of the heat treatment zone of the heat treatment furnace for waste glass of this embodiment will be described in detail. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 shows an exploded perspective view of a part of the heat treatment zone. Note that the azimuths (left and right) in the drawings after FIG.

  As shown in FIGS. 2 and 3, the furnace wall 20 includes a steel frame 200 and a refractory 201. The heat treatment zone B is divided into a lower chamber 22D and an upper chamber 22U with the mesh belt 30 as a boundary. A waste laminated glass W is placed on the mesh belt 30.

  A burner 60L is inserted into the lower chamber 22D through the left wall portion of the furnace wall 20. As shown in FIG. 3 and FIG. 1, the burners 60L (shown by a circle in FIG. 1) and 60R (shown by a cross in FIG. 1) are arranged along the longitudinal direction of the furnace wall 20. Alternatingly arranged on the left and right walls. A collection tray 80 is laid on the floor of the lower chamber 22D. The collection tray 80 is made of SUS430 and has a dish shape. The collection tray 80 is disposed over substantially the entire length of the furnace wall 20. The temperature control unit 7a for the lower chamber of the heat treatment zone includes a thermocouple 70a, a temperature controller 71a, and a control valve 72a. Among these, the thermocouple 70 a is inserted into the lower chamber 22 </ b> D via the right wall portion of the furnace wall 20. On the other hand, the control valve 72a is disposed in the energy supply pipe 600L of the burner 60L. The temperature controller 71a is interposed between the thermocouple 70a and the control valve 72a.

  A burner 61R is inserted into the upper chamber 22U through the right wall portion of the furnace wall 20. In addition, an oxygen introduction pipe 62 </ b> L is disposed through the left wall portion of the furnace wall 20. As shown in FIG. 1, the burners 61R (indicated by x in FIG. 1) and 61L (indicated by ○ in FIG. 1) are provided on the left and right wall portions along the longitudinal direction of the furnace wall 20. Are alternately arranged. In addition, oxygen introduction pipes 62L (not shown in FIG. 1) are also alternately arranged on the left and right wall portions along the longitudinal direction of the furnace wall 20. The heat treatment zone upper chamber temperature controller 7b includes a thermocouple 70b, a temperature controller 71b, and a control valve 72b. Among these, the thermocouple 70 b is inserted into the upper chamber 22 </ b> U via the top wall portion of the furnace wall 20. On the other hand, the control valve 72b is disposed in the oxygen introduction pipe 62L. The temperature controller 71b is interposed between the thermocouple 70b and the control valve 72b.

(Configuration of heating zone)
Next, the structure of the heating zone of the heat treatment furnace for waste glass of this embodiment will be described in detail. In addition, description is abbreviate | omitted about the part which is common in the said heat processing zone B. FIG. 4 is a sectional view taken along the line IV-IV in FIG. As shown in FIG. 4, a burner 63 </ b> L is inserted through the left wall portion of the furnace wall 20 in the lower stage of the mesh belt 30 in the heating zone A (specifically, the space below the mesh belt 30. The same applies hereinafter). As shown in FIG. 1, the burners 63L (shown by a circle in FIG. 1) and 63R (shown by a x in FIG. 1) are provided on the left and right wall portions along the longitudinal direction of the furnace wall 20. Are alternately arranged.

  The heating zone temperature controller 7c includes a thermocouple 70c, a temperature controller 71c, and a control valve 72c. Among these, the thermocouple 70 c is inserted in the lower stage of the mesh belt 30 in the heating zone A through the right wall portion of the furnace wall 20. In addition, the thermocouple 70d is inserted through the top wall portion of the furnace wall 20 into the upper stage of the mesh belt 30 in the heating zone A (specifically, the space above the mesh belt 30; the same applies hereinafter). On the other hand, the control valve 72c is disposed in the energy supply pipe 630L of the burner 63L. The temperature controller 71c is interposed between the thermocouples 70c and 70d and the control valve 72c.

(Temperature pattern and temperature control of heat treatment furnace for waste glass)
Next, the temperature pattern and temperature control of the heat treatment furnace for waste glass of this embodiment will be described. First, the temperature pattern of the heating zone A will be described. In FIG. 5, the temperature pattern of the heat treatment furnace for waste glass of this embodiment is shown. As shown in FIG. 5, the passing time of the heating zone A is 10 minutes. The temperature of the upper stage of the mesh belt 30 in the heating zone A rises from about 20 ° C. to about 400 ° C. in the first 5 minutes (heating rate of about 76 ° C./min), and is maintained at about 400 ° C. for the next 3 minutes. It is set to increase from about 400 ° C. to about 620 ° C. in the last 2 minutes (heating rate of about 110 ° C./min). In addition, the temperature of the lower stage of the mesh belt 30 in the heating zone A rises from about 20 ° C. to about 400 ° C. in the first 5 minutes (heating rate of about 76 ° C./min), and remains at about 400 ° C. in the second half Is set to be. In the heating zone A, the waste laminated glass W is heated from about 20 ° C. to about 600 ° C. That is, the temperature increase rate of the waste laminated glass W is about 58 ° C./min.

  The temperature control in the heating zone A is performed by the heating zone temperature controller 7c. That is, the actual measured value of the lower temperature of the mesh belt 30 in the heating zone A is input from the thermocouple 70c to the temperature controller 71c as shown in FIG. In addition, the actual measured value of the upper temperature of the mesh belt 30 in the heating zone A is input from the thermocouple 70d to the temperature controller 71c. Each temperature target value of the upper and lower stages of the mesh belt 30 is set in advance in the temperature controller 71c. The temperature controller 71c compares the temperature target value with the actual measurement values input from the thermocouples 70c and 70d. Based on the comparison result, a drive instruction is issued to the control valve 72c in order to bring the actual measurement value closer to the temperature target value. Thus, the heating zone temperature controller 7c performs temperature control of the heating zone A by feedback control. And the heating zone A is controlling the temperature increase rate of the waste laminated glass W to about 58 degreeC / min.

  Second, the temperature pattern of the heat treatment zone B will be described. As shown in FIG. 5, the passage time of the heat treatment zone B is 20 minutes. The temperature of the upper chamber 22U of the heat treatment zone B is constant at about 620 ° C. except near the downstream end. In addition, the temperature of the lower chamber 22D of the heat treatment zone B is constant at about 400 ° C. except near the downstream end. Further, the temperature of the waste laminated glass W is constant at about 600 ° C. except for the vicinity of the downstream end.

  The temperature control in the heat treatment zone B is performed by the heat treatment zone lower chamber temperature controller 7a and the heat treatment zone upper chamber temperature controller 7b. That is, the measured value of the temperature of the lower chamber 22D is input from the thermocouple 70a to the temperature controller 71a as shown in FIG. A temperature target value for the lower chamber 22D is set in advance in the temperature controller 71a. The temperature controller 71a compares the temperature target value with the actual measurement value input from the thermocouple 70a. Based on the comparison result, a drive instruction is issued to the control valve 72a in order to bring the actual measurement value closer to the temperature target value. As described above, the temperature control section 7a for the heat treatment zone lower chamber performs temperature control of the lower chamber 22D of the heat treatment zone B by feedback control.

  On the other hand, the actual measured value of the temperature in the upper chamber 22U is input from the thermocouple 70b to the temperature controller 71b as shown in FIG. A temperature target value for the upper chamber 22U is set in advance in the temperature controller 71b. The temperature controller 71b compares the temperature target value with the actual measurement value input from the thermocouple 70b. Then, based on the comparison result, a drive instruction is issued to the control valve 72b in order to bring the actual measurement value closer to the temperature target value. As described above, the temperature control unit 7b for the heat treatment zone upper chamber performs temperature control of the upper chamber 22U of the heat treatment zone B by feedback control. In the heat treatment zone B, the temperature of the waste laminated glass W is constantly controlled to about 600 ° C. except for the vicinity of the downstream end.

(Movement of waste glass)
Next, the movement of the waste laminated glass passing through the heat treatment furnace for waste glass of this embodiment will be described. The waste laminated glass W is placed on the mesh belt 30 from the rear end of the furnace body 2 (see FIG. 1 above). The placed laminated glass W enters the heating zone A as the mesh belt 30 moves. FIG. 6 shows a cross-sectional view of the waste laminated glass before entering the heating zone. As shown in FIG. 6, the waste laminated glass W includes a pair of glass layers W1 and W2 and a resin layer W3. The resin layer W3 is interposed between the pair of glass layers W1 and W2. The resin layer W3 is made of PVB resin. The resin layer W3 is firmly bonded to the glass layers W1 and W2. A large number of cracks C are formed in the glass layers W1 and W2 from the outside to the resin layer W3.

  The waste laminated glass W heated up by passing through the heating zone A enters the heat treatment zone B as the mesh belt 30 moves. FIG. 7 shows a cross-sectional view of the waste laminated glass after passing through the heating zone and before entering the heat treatment zone. As shown in FIG. 7, the resin layer W3 is softened. For this reason, the cracks C of the glass layers W1 and W2 are wide open. In addition, since the heating rate of the waste laminated glass W in the heating zone A is as high as about 58 ° C./min, cracks C are newly generated in the glass layers W1 and W2. In this state, the waste laminated glass W enters the heat treatment zone B. The temperature of the lower chamber 22D of the heat treatment zone B is set to about 400 ° C. That is, the temperature is set higher than the evaporation start temperature of the PVB resin. For this reason, the PVB resin, that is, the resin layer W3 evaporates to become a combustible evaporated gas.

  The combustible evaporated gas flows out of the glass layers W1 and W2 through the widely opened crack C. The flammable evaporated gas that has flowed out rises in the upper chamber 22U as shown by the white arrow in FIG. A part of the combustible vapor is combusted by oxygen introduced into the upper chamber 22U from the oxygen introduction pipe 62L. The upper chamber 22U is heated by the combustion. However, the temperature of the upper chamber 22U is maintained at about 620 ° C. by the heat treatment zone upper chamber temperature controller 7b described above.

Incidentally, PVB resin reaction during complete combustion of _{(- (- - CH 2 CHOCOC} 2 H 5) n-) is given by the following equation.
_{(-CH 2 CHOCOC 2 H 5 -} ) n + 6nO 2 = 5nCO 2 + 4nH 2 O ··· (1)
After combustion or unburned exhaust gas is collected by an exhaust gas collecting pipe 40 and subjected to secondary combustion in an exhaust gas treatment furnace 41 as shown in FIG. The exhaust gas after the secondary combustion is discharged out of the system through the dust collector 42, the blower 43, and the discharge port 44. Since the emitted exhaust gas is relatively high in temperature, it is reused as a heat source such as a drying furnace (not shown). The exhaust gas generated in the heating zone A is treated in the same manner.

  The waste laminated glass W after passing through the heat treatment zone B is thrown into the pit 5 from the front end of the furnace body 2 (see FIG. 1) as the mesh belt 30 is turned back. FIG. 8 shows a cross-sectional view of the waste laminated glass after passing through the heat treatment zone. As shown in FIG. 8, the resin layer has completely evaporated and disappeared. Moreover, the glass layers W1 and W2 are not softened or melted.

(Function and effect)
Next, the effect of the heat treatment furnace for waste glass of this embodiment will be described. The waste glass heat treatment furnace 1 of the present embodiment includes a lower chamber 22D disposed below and an upper chamber 22U disposed above with the mesh belt 30 as a boundary. The temperature of the lower chamber 22D is controlled to about 400 ° C. For this reason, the resin layer W3 of the waste laminated glass W placed on the mesh belt 30 is evaporated by the heat of the lower chamber 22D. The resin layer W3 evaporates to become a combustible evaporated gas. The upper chamber 22U is heated by burning a part of the combustible vaporized gas. The temperature of the upper chamber 22U is controlled to about 620 ° C.

  As described above, the waste glass heat treatment furnace 1 of the present embodiment heats the upper chamber 22U by utilizing the combustion of combustible evaporative gas. Further, the temperature in the furnace is controlled using a temperature gradient in the furnace from the lower chamber 22D to the upper chamber 22U. For this reason, running cost is low.

  The lower chamber 22D is temperature controlled to be equal to or higher than the evaporation start temperature of the PVB resin and lower than the glass softening temperature, and the upper chamber 22U is lower than the glass softening temperature. For this reason, there is little possibility that the carbides (burning residue) of the resin layer W3 remain in the glass layers W1 and W2 after collection (after heat treatment). In addition, the glass layers W1 and W2 after recovery are less likely to soften and melt. Therefore, the quality of the recovered glass layers W1, W2 is high.

  In addition, according to the heat treatment furnace for waste glass 1 of the present embodiment, the waste laminated glass W can be heated and heat-treated while being conveyed by the mesh conveyor 3. For this reason, the glass layers W1 and W2 in the waste laminated glass W can be continuously collected.

  Further, as shown in FIG. 5, the rate of temperature increase of the waste laminated glass W in the heating zone A is set to about 58 ° C./min, which is higher than 50 ° C./min. For this reason, before reaching the heat treatment zone B, the temperature of the waste laminated glass W can be quickly raised. Moreover, the crack C can be generated in the glass layers W1 and W2 during the temperature rise. When the number of cracks C in the glass layers W1 and W2 increases, the flammable evaporated gas can be released more easily through the large number of cracks C in the heat treatment zone B. For this reason, the carbide | carbonized_material of the resin layer W3 does not remain easily in the glass layers W1 and W2 after collection | recovery.

  Further, according to the waste glass heat treatment furnace 1 of the present embodiment, as shown in FIG. 1, the burners 60L and 60R are arranged in the lower chamber 22D. In addition, as shown in FIG. 2, an oxygen introduction pipe 62L is arranged in the upper chamber 22U. For this reason, a part of combustible evaporation gas can be burned comparatively easily by generating combustible evaporation gas by burners 60L and 60R, and supplying oxygen from oxygen introduction piping 62L. That is, the upper chamber 22U can be heated.

  In addition, according to the waste glass heat treatment furnace 1 of the present embodiment, the burners 61L and 61R in the upper chamber 22U are at the same level as the igniting fire of combustible evaporative gas except when the waste glass heat treatment furnace 1 is started. Only used. In this respect, the running cost is low.

  Moreover, according to the heat treatment furnace 1 for waste glass of this embodiment, the mesh belt 30 and the collection tray 80 are both made of SUS430. That is, it is made of metal that does not contain nickel. As shown in FIG. 5, the temperature of the lower chamber 22D and the lower zone of the heating zone A (up to about 400 ° C.) is relatively low, so even such a material can be used sufficiently. Therefore, compared with the case where the mesh belt 30 and the collection tray 80 are made of nickel-containing metal (for example, SUS310S (austenite)), the equipment cost can be reduced. Further, the waste glass W falling off from the mesh belt 30 can be recovered relatively easily by the recovery tray 80.

  When the mesh belt 30 and the recovery tray 80 are made of nickel-containing metal, nickel may be mixed into the recovered glass layers W1 and W2 depending on the temperature of the lower chamber 22D. In this regard, according to the waste glass heat treatment furnace 1 of the present embodiment, as described above, the mesh belt 30 and the collection tray 80 are both made of SUS430. For this reason, there is no possibility that nickel will mix in the glass layers W1 and W2 after collection. Therefore, the recovery yield is improved.

  Further, according to the heat treatment furnace for waste glass 1 of the present embodiment, the temperature of the upper chamber 22U is controlled to about 620 ° C. as shown in FIG. For this reason, even if the combustion of the combustible evaporative gas suddenly becomes intense, the temperature of the upper chamber 22U can be suppressed to less than the glass softening temperature (about 720 ° C.). Therefore, the quality of the recovered glass layer is increased.

  Moreover, the waste glass used as the process target of the heat treatment furnace 1 for waste glass of this embodiment is the waste laminated glass W in which the crack C has entered beforehand as shown in FIG. For this reason, combustible vaporized gas is more easily released from the resin layer W3 than when the entire front and back surfaces of the resin layer W3 are covered with the glass layers W1 and W2 (when there is no crack C). Therefore, the carbide of the resin layer W3 hardly remains in the recovered glass layers W1 and W2. Moreover, according to the heat treatment furnace 1 for waste glass of this embodiment, harmful dioxin etc. do not generate | occur | produce as shown in Formula (1). For this reason, the equipment cost of the exhaust gas treatment equipment 4 is low.

<Second embodiment>
The difference between the heat treatment furnace for waste glass of this embodiment and the heat treatment furnace for waste glass of the first embodiment is that a watering nozzle is arranged in the upper chamber. Therefore, only the differences will be described here.

  FIG. 9 is a cross-sectional view in the short-side direction of the heat treatment zone of the waste glass heat treatment furnace of the present embodiment. In addition, about the site | part corresponding to FIG. 2, it shows with the same code | symbol. As shown in FIG. 9, a pair of watering nozzles 81 is disposed on the top wall portion of the furnace wall 20 with a thermocouple 70 b interposed therebetween. The watering nozzle 81 is included in the watering device of the present invention.

  The heat treatment furnace for waste glass of the present embodiment has the same effects as the heat treatment furnace for waste glass of the first embodiment with respect to the parts having the same configuration. In addition, according to the heat treatment furnace for waste glass of the present embodiment, it is possible to burn all combustible vapors. The reason is that even if the temperature of the upper chamber 22U is likely to rise due to the combustion heat of the combustible evaporative gas, the temperature of the upper chamber 22U can be forcibly lowered by injecting water from the watering nozzle 81. It is. For this reason, it can suppress reliably that the temperature of the upper chamber 22U becomes more than a glass softening temperature. Further, the temperature control of the upper chamber 22U is simplified.

<Third embodiment>
The difference between the heat treatment furnace for waste glass of this embodiment and the heat treatment furnace for waste glass of the first embodiment is that the temperature control of the upper chamber is not an increase or decrease in the amount of oxygen in the oxygen introduction pipe, but the energetic fluid supplied to the burner (For example, oxygen, fuel gas, mixed gas of oxygen and fuel gas, etc.) Therefore, only the differences will be described here.

  FIG. 10 is a cross-sectional view in the short-side direction of the heat treatment zone of the waste glass heat treatment furnace of this embodiment. In addition, about the site | part corresponding to FIG. 2, it shows with the same code | symbol. As shown in FIG. 10, the control valve 72b of the heat treatment zone upper chamber temperature controller 7b is arranged not in the oxygen introduction pipe 62L (see FIG. 2 above) but in the energy supply pipe 610R of the burner 61R.

  The heat treatment furnace for waste glass of the present embodiment has the same effects as the heat treatment furnace for waste glass of the first embodiment with respect to the parts having the same configuration. Like the heat treatment furnace for waste glass of this embodiment, the temperature of the upper chamber 22U may be controlled by increasing or decreasing the energy fluid supplied to the burner 61R.

<Others>
The embodiment of the heat treatment furnace for waste glass of the present invention has been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  For example, the thermoplastic resin included in the resin layer W3 may not be a PVB resin. It may be a polyurethane resin or an ethylene vinyl acetate copolymer. Further, a plasticizer, an ultraviolet absorber, an antioxidant and the like may be included.

  Moreover, in the said embodiment, although the heating zone A was arrange | positioned in the upstream of the heat processing zone B, you may implement in the form which does not arrange the heating zone A. If it carries out like this, an installation cost and a running cost can be reduced further.

  Moreover, in the said embodiment, although the waste laminated glass W was conveyed by the mesh belt 30, you may convey the waste laminated glass W by the punching metal conveyor belt which has many pores, for example.

  Moreover, in the said embodiment, although the waste laminated glass W was heat-processed, you may heat-process a liquid crystal display, the glass panel of a solar cell, etc. Further, the glass layers W1 and W2 may not be disposed on both surfaces of the resin layer W3. For example, even if the glass layer is disposed only on one side or a part of one side of the resin layer W3, the glass layer can be recovered by the waste glass heat treatment furnace 1 of the present embodiment. Moreover, in the said embodiment, although the waste-heat-treatment furnace for waste glass of this invention was embodied as the continuous-type waste-glass heat treatment furnace 1, it is good also as a batch type.

  In addition, the types of energy supply pipes 600L, 610R, and 630L in the above embodiment are not particularly limited. For example, a pipe for supplying oxygen to the burner or a pipe for supplying fuel gas to the burner may be used. Moreover, when supplying the mixed gas which mixed oxygen with fuel gas beforehand to a burner by single piping, the piping for supplying the said mixed gas may be sufficient.

It is longitudinal direction sectional drawing of the heat treatment furnace for waste glass of 1st embodiment. It is II-II sectional drawing of FIG. It is a perspective exploded view of a part of the heat treatment zone of the heat treatment furnace for waste glass. It is IV-IV sectional drawing of FIG. It is a graph which shows the temperature pattern of the heat processing furnace for the waste glass. It is sectional drawing of the waste laminated glass before a heating zone approach. It is sectional drawing of the waste glass after passing through a heating zone and before entering into a heat treatment zone. It is sectional drawing of the waste laminated glass after passing through the heat treatment zone. It is a transversal direction sectional view of the heat treatment zone of the heat treatment furnace for waste glass of a second embodiment. It is a transversal direction sectional view of the heat treatment zone of the heat treatment furnace for waste glass of a third embodiment.

Explanation of symbols

1: Heat treatment furnace for waste glass.
2: furnace body, 20: furnace wall, 200: frame, 201: refractory, 21: leg, 22D: lower chamber, 22U: upper chamber.
3: Mesh conveyor, 30: Mesh belt, 31: Roller.
4: exhaust gas treatment facility, 40: exhaust gas collecting pipe, 41: exhaust gas treatment furnace, 42: dust collector, 43: blower, 44: discharge port.
5: Pit.
60L: Burner, 600L: Energy supply pipe, 60R: Burner, 61L: Burner, 61R: Burner, 610R: Energy supply pipe, 62L: Oxygen introduction pipe, 63L: Burner, 630L: Energy supply pipe, 63R: Burner.
7a: Temperature control unit for heat treatment zone lower chamber, 7b: Temperature control unit for heat treatment zone upper chamber, 7c: Temperature control unit for heating zone, 70a to 70d: Thermocouple, 71a to 71c: Temperature controller, 72a to 72c: Control valve.
80: collection tray, 81: watering nozzle (watering device).
A: heating zone, B: heat treatment zone, C: crack, G: ground, W: waste laminated glass, W1: glass layer, W2: glass layer, W3: resin layer.

Claims (10)

A waste glass formed by laminating a glass layer and a resin layer containing a thermoplastic resin bonded to the glass layer is placed, and a table having air permeability,
A lower chamber disposed below the table and temperature-controlled above the evaporation start temperature of the thermoplastic resin;
An upper chamber disposed above the table and temperature controlled below the glass softening temperature of the glass layer;
A heat treatment furnace for waste glass comprising: Furthermore, a heat treatment zone having the lower chamber and the upper chamber;
A heating zone connected to the upstream side of the heat treatment zone for heating the waste glass,
The heat treatment furnace for waste glass according to claim 1, wherein the table is a mesh belt of a mesh conveyor that conveys the waste glass from the heating zone to the heat treatment zone, and continuously heat-treats the waste glass.   The heat treatment furnace for waste glass according to claim 2, wherein the temperature increase rate of the waste glass in the heating zone is greater than 50 ° C./min. And a burner disposed in the lower chamber for evaporating the thermoplastic resin into a flammable vapor,
An oxygen introduction pipe disposed in the upper chamber for burning at least a part of the combustible vapor;
The heat treatment furnace for waste glass in any one of Claims 1 thru | or 3 which has these.   Furthermore, the heat processing furnace for waste glass in any one of Claim 1 thru | or 4 which has a watering apparatus which is arrange | positioned in the said upper chamber, and suppresses that the temperature of this upper chamber becomes more than the said glass softening temperature. The thermoplastic resin is a polyvinyl butyral resin,
The heat treatment furnace for waste glass according to any one of claims 1 to 5, wherein the temperature of the lower chamber is controlled to be 400 ° C or higher and 450 ° C or lower.   The heat treatment furnace for waste glass according to claim 6, wherein the table is made of a metal not containing nickel.   Furthermore, the heat processing furnace for waste glass of Claim 6 or Claim 7 which is made of the metal which does not contain nickel, and the collection | recovery tray which collect | recovers the said waste glass which fell out of the said table is laid.   The heat treatment furnace for waste glass according to any one of claims 1 to 8, wherein the temperature of the upper chamber is controlled to 650 ° C or lower.   The waste glass is waste laminated glass in which a pair of glass layers are bonded to each other via the resin layer, and a crack is formed in the glass layer from the outside to the resin layer. The heat processing furnace for waste glass in any one of Claim 9 thru | or 9.

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