JP5720898B2 - Glass melting apparatus, molten glass supply method, and outflow passage for melting furnace - Google Patents

Description

  The present invention relates to a glass melting apparatus, a molten glass supply method, and an outflow passage for a melting furnace, and more specifically, after heating and melting a glass raw material charged in a melting furnace to produce a molten glass, The present invention relates to an improvement in technology for causing the molten glass to flow out of a melting furnace.

  As is well known, molten glass is produced by mixing and mixing glass raw materials represented by silica sand, limestone, soda ash, cullet and the like and then heating. The melting temperature depends on the glass type, but is about 1500 ° C., for example. As an apparatus for producing molten glass, a glass melting apparatus as shown in FIG. 9 is widely used.

  FIG. 9 is a side view showing a configuration example of a conventional glass melting apparatus. As shown in the figure, this glass melting apparatus 1 uses a glass raw material C charged into a melting furnace 2 from a charging port 6 in the melting furnace 2 using a burner, an electric heater, energization in the molten glass, and the like. The molten glass G is generated by heating and melting. Then, the generated molten glass G is configured to flow out of the melting furnace 2 from the outlet 3 formed on the downstream side wall 2 a in the melting furnace 2.

  Each arrow 7-10 shown in the figure shows the convection of the molten glass G in the melting furnace 2, and is formed by the force by the pushing of the glass raw material C from a charging machine, or a thermal convection. Among these flows of molten glass G, the important factor that determines the quality of the glass product that is finally produced is after flowing down in the melting furnace 2 along the side wall 2a indicated by the arrow 10. This is a flow that flows into the outlet 3.

  More specifically, in the melting furnace, a large number of bubbles are generated when the glass raw material C is melted. The bubbles float in the melting furnace 2 during the melting process and form a bubble layer in the vicinity of the glass surface S. To do. This foam layer gradually disappears as it moves away from the inlet 6, but in the region A indicated by cross hatching in the figure, the foam layer remaining without disappearing may stay in place. .

  Further, in the melting process, a part of the glass component volatilizes from the glass surface S, and for example, a base of the heterogeneous molten glass G having a high silica content may be generated. This inhomogeneous glass substrate flows in the vicinity of the glass surface S toward the side wall 2a and reaches the region A.

  For this reason, among the bubbles and heterogeneous glass bodies (hereinafter collectively referred to as “heterogeneous substrates”) that have reached the region A, the heterogeneous substrates existing above the outflow port 3 follow the flow indicated by the arrow 10. The situation where it flows into the outflow port 3 and flows out of the melting furnace 2 was invited. And due to this, there is a problem that defects are contained in the finally manufactured glass product, and the quality of the product is greatly deteriorated.

  Therefore, in order to solve such a problem, configurations as disclosed in the following Patent Documents 1 and 2 have been proposed as means for suppressing the outflow of the heterogeneous substrate to the outside of the melting furnace.

  Patent Document 1 discloses a configuration in which a plate protruding from the side wall into the melting furnace is provided above the outlet formed in the downstream side wall of the melting furnace. Further, Patent Document 2 has a configuration in which an outflow passage for molten glass protruding from the downstream side wall in the melting furnace into the melting furnace and an exhaust passage for discharging the heterogeneous material above the outflow passage are provided. It is disclosed.

JP 2003-95662 A Japanese Utility Model Publication 3-54118

  However, it has been found by the present inventor that any of the configurations disclosed in Patent Documents 1 and 2 does not provide an effect sufficient to solve the above-described problem.

  Specifically, according to the configuration disclosed in Patent Document 1, the presence of a plate protruding into the melting furnace from the side wall above the outlet includes a heterogeneous substrate that flows down in the melting furnace along the side wall. It is possible to avoid the molten glass flowing directly into the outlet. However, the flow that flows down and reaches the surface of the plate only bypasses the plate along the front and back surfaces of the plate, and eventually flows into the outlet and out of the melting furnace. It has become clear.

  Moreover, according to the structure disclosed by patent document 2, it can anticipate reducing the inflow to the outflow channel | path of a heterogeneous base material. However, in this configuration, since it is necessary to provide a discharge passage on the side wall, an extra equipment cost is generated, and the amount of glass that can be formed is reduced by the amount of molten glass discharged from the discharge passage. In addition, in order to use the discharged molten glass again for the production of glass, it is necessary to once return it to the raw material as a glass cullet and then melt it again, resulting in extra costs.

  Further, the heterogeneous substrate that could not be discharged in the discharge passage flows down along the side wall, reaches the upper portion and the side portion of the outflow passage, and then the upper portion, the side portion, and the outflow passage that protrudes into the melting furnace. It has been found that the outflow passage is bypassed along the bottom of the melting furnace adjacent to the side and follows the path out of the melting furnace. In other words, compared to the case where no outflow passage projecting into the melting furnace is provided, the path from which the heterogeneous base reaches the outside of the melting furnace is only extended, and as a result, it flows out of the melting furnace. There was no change. Therefore, even with this configuration, it has been difficult to effectively suppress the outflow of the heterogeneous material to the outside of the melting furnace.

  This invention made | formed in view of the said situation makes it a technical subject to suppress as much as possible the quantity which the heterogeneous base generate | occur | produced in the melting furnace flows out out of a melting furnace with molten glass.

  The apparatus according to the present invention, which was created to solve the above problems, includes a melting furnace that generates or heats molten glass, and projects from the side wall on the downstream side of the melting furnace toward the inside of the melting furnace. An apparatus for melting glass comprising an outflow passage having a glass inflow hole, comprising: a roof that covers at least a part of the upper portion of the outflow passage that is continuous from the side wall side of the melting furnace; And a molten glass guiding surface comprising an inclined plane that is inclined downward toward the side portion or the side wall of the outflow passage.

  According to such a configuration, when the roof has a molten glass guiding surface composed of an inclined plane that is inclined downward toward the side of the outflow passage, the roof flows down along the side wall and reaches the top of the roof. The molten glass containing the heterogeneous substrate is guided to the molten glass guiding surface and actively flows to the side of the outflow passage. Thereafter, it has been found that it further flows down in the melting furnace and reaches the bottom of the melting furnace. In addition, when the roof has a molten glass guiding surface composed of an inclined plane that is inclined downward toward the side wall, the molten glass including the heterogeneous base material flows toward the front end side of the outflow passage along the roof. It is suppressed. And after the said molten glass is extruded to the side part of an outflow passage by the subsequent molten glass which flows down to the upper part of a roof sequentially, it further flows down in the melting furnace and reaches the bottom of the melting furnace. It has been found. Thereby, the outflow passage is detoured along the melting furnace bottom adjacent to the upper portion, the side portion, and the side portion of the outflow passage, and the heterogeneous substrate detouring along the upper portion outflows out of the melting furnace. The amount flowing out of the melting furnace can be suppressed.

  In the above configuration, the molten glass guide surface has a first inclined plane that is inclined downward toward the one side portion of the outflow passage and a downward inclination toward the other side portion of the outflow passage. And a second inclined plane.

  In this way, the molten glass containing the heterogeneous base material that has reached the upper part of the roof, along the first inclined plane and the second inclined plane, the one side and the other side of the outflow passage It can be made to flow down while being guided to.

  In the above configuration, it is preferable that the first inclined plane and the second inclined plane are in contact with each other to form the top of the roof.

  In this way, the molten glass containing the heterogeneous base material that has reached the top of the roof is more smoothly disposed on one side of the outflow passage by the first inclined plane and the second inclined plane being in contact with each other at the top. It will be induced to the side and the other side. For this reason, it can suppress more effectively that a heterogeneous substrate bypasses an outflow passage along the upper part of an outflow passage, and flows out out of a melting furnace with molten glass.

  In the above configuration, the inflow hole is opened at an upper portion separated from the bottom of the melting furnace in a passage constituting wall that divides the inside and outside of the outflow passage, and at the top of the outflow passage, at the tip side from the roof It is preferable to be formed.

  If it does in this way, it will become easy to flow into the outflow passage through the inflow hole. For this reason, the flow of this homogeneous molten glass becomes a dominant flow in the flow of the molten glass flowing through the outflow passage, and the flow rate is increased. Thereby, the bottom part adjacent to the side part and the side part among the heterogeneous base material that bypasses the outflow passage along the top part, the side part, and the bottom part of the melting furnace adjacent to the side part and flows out to the outside of the melting furnace. The amount of the heterogeneous base material that detours along the line flows out of the melting furnace is reduced.

  Said structure WHEREIN: The said inflow hole may be formed in the front end side edge part in the upper part of the said outflow passage.

  If this is done, the distance from the side wall of the melting furnace to the inflow hole is increased, so that the molten glass that flows down the melting furnace along the side wall and reaches the upper part of the roof reaches the upper part of the roof. Bypassing the outflow passage along the upper portion of the passage, it becomes difficult to flow out of the melting furnace.

  In the above configuration, the roof may extend from a side wall of the melting furnace to an edge of the inflow hole in an upper part of the outflow passage.

  If it does in this way, it can control more effectively that molten glass containing a heterogeneous substrate bypasses an outflow passage along the upper part of an outflow passage, and flows out of a melting furnace.

  Said structure WHEREIN: It is preferable that the front-end | tip part of the said outflow passage is sealed.

  If it does in this way, the following preferable aspects will be obtained about the molten glass containing the heterogeneous base induced | guided | derived to the side part of an outflow passage. That is, a part of the molten glass that has reached the side portion of the outflow passage flows toward the front end portion of the outflow passage along the side portion of the outflow passage and the bottom adjacent to the side portion by natural convection, and then the outflow passage. Although it is going to flow in, since the front-end | tip part is sealed, it becomes possible to block the flow of this molten glass. Thereby, the outflow of the heterogeneous substrate to the outside of the melting furnace can be further effectively suppressed.

  Said structure WHEREIN: It is preferable that the said outflow passage whole is located away from the bottom part of the said melting furnace upwards.

  In this way, since the outflow passage is positioned higher in the melting furnace, melting of the molten glass that bypasses the outflow passage along the bottom of the melting furnace out of the molten glass containing the heterogeneous substrate. The effect of suppressing outflow from the furnace is further enhanced.

  Said structure WHEREIN: The lower part may be comprised by the bottom part of the said melting furnace among the channel | path structural walls of the said outflow passage.

  In this way, it is not necessary to separately provide a lower portion of the passage-constituting wall, and the outflow passage can be easily formed, so that the equipment cost can be reduced.

  Said structure WHEREIN: It is preferable that a part or all of the said outflow channel and the said roof is formed with the platinum group element, the alloy containing a platinum group element, or molybdenum.

  In this way, since the corrosion resistance is improved, it is possible to suppress the outflow of the heterogeneous base caused by the erosion of the outflow passage and the roof and the deformation of the outflow passage and the roof.

  In the above configuration, the apparatus includes a plurality of the melting furnaces, and has a connection portion that connects the adjacent melting furnaces, and at least one of the connection portions is configured by the outflow passage, and an upper portion of the outflow passage. May be covered by the roof.

  In this way, when all of the plurality of connecting portions are constituted by outflow passages, it is possible to suppress outflow of the heterogeneous substrate from the melting furnace that may occur in each melting furnace. Further, when some of the plurality of connecting portions are constituted by outflow passages, the outflow passage is connected to a connecting portion that connects a melting furnace where the outflow of the heterogeneous base is remarkable and a melting furnace located downstream thereof. If it comprises, the outflow of a heterogeneous base material can be suppressed, preventing the increase in equipment cost.

  Further, the method according to the present invention, which was created to solve the above-described problems, includes an outflow passage that projects molten glass generated or heated in a melting furnace from a downstream side wall of the melting furnace into the melting furnace. The molten glass is supplied from the melting furnace to the outside of the melting furnace, and the outflow passage includes a roof that covers at least a part of the upper part of the molten glass that is continuous from the side wall side of the melting furnace. The roof is characterized by having a molten glass guiding surface composed of an inclined flat surface that is inclined downward toward a side portion or the side wall of the outflow passage.

  According to such a method, it is possible to enjoy the same operational effects as those already described in the description of the above apparatus.

  Furthermore, an apparatus according to the present invention created to solve the above-mentioned problems is an outflow passage for a melting furnace provided in the melting furnace for letting out the molten glass, and is an upper part of the outflow passage. A roof covering at least a partial region continuous from one end of the outflow passage, and the roof has a molten glass guiding surface composed of an inclined flat surface descending toward a side portion of the outflow passage or toward the one end side. It is characterized by that.

  If such an outflow passage is installed in the melting furnace, it is possible to enjoy the same operational effects as those already described in the description of the glass melting apparatus.

  As described above, according to the present invention, it is possible to suppress as much as possible the amount of the heterogeneous substrate generated in the melting furnace flowing out of the melting furnace together with the molten glass.

1 is a perspective view showing a glass melting apparatus according to a first embodiment of the present invention. It is a front view which shows the melting apparatus of the glass which concerns on 1st embodiment of this invention, and the behavior of molten glass. It is a side view which shows the melting apparatus of the glass which concerns on 1st embodiment of this invention, and the behavior of molten glass. It is a top view which shows the melting apparatus of the glass which concerns on 1st embodiment of this invention, and the behavior of molten glass. FIGS. 5A and 5B are perspective views showing a glass melting apparatus according to the second and third embodiments of the present invention. It is a side view which shows the glass melting apparatus which concerns on 4th embodiment of this invention. It is the schematic which shows the glass melting apparatus used for the comparative example based on a prior art, and the Example of this invention, and the behavior of molten glass. It is the schematic which shows the glass melting apparatus used for the comparative example based on a prior art, and the Example of this invention, and the behavior of molten glass. It is a side view which shows the conventional glass melting apparatus.

  Hereinafter, a glass melting apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing a glass melting apparatus 1 (hereinafter simply referred to as a melting apparatus 1) according to a first embodiment of the present invention. As shown in the figure, a melting apparatus 1 includes a melting furnace 2 that generates molten glass G, an outlet 3 that causes the molten glass G in the melting furnace 2 to flow out of the melting furnace 2, and a melt at the outlet 3. An outflow passage 4 through which the glass G flows in and a roof 15 covering the outflow passage 4 are provided.

  The melting furnace 2 has a rectangular cross-sectional shape, and includes a glass raw material inlet at the upstream end (not shown) and heating means, and heats the glass raw material charged into the melting furnace 2, Molten glass G is produced by melting.

  The outlet 3 is formed on the side wall 2 a that is the downstream end of the melting furnace 2, and is positioned away from the bottom 2 b of the melting furnace 2, and the molten glass G is discharged from the melting furnace 2 through the outflow passage 4. It flows out of the melting furnace 2.

  The outflow passage 4 is located on the base 5, and is located away from the bottom 2 b of the melting furnace 2. The outflow passage 4 has a downstream end abutting against the side wall 2a and connected to the outlet 3 without a gap, and protrudes from the side wall 2a toward the upstream side in the melting furnace 2, and has an upstream end portion. An inflow hole 4b having a rectangular shape for allowing the molten glass G in the melting furnace 2 to flow into the flow path 4a and opening upward is formed in the upper portion of. Further, the flow path 4a formed by the passage constituting wall of the outflow passage 4 and through which the molten glass G flows has a rectangular cross-sectional shape, and a sealing plate 4c that blocks the inflow port of the outflow passage 4 at the upstream end thereof. Is provided. The outflow passage 4 is covered with platinum.

  The roof 15 is in contact with the side wall 2a at the downstream end thereof, and covers a portion on the downstream side of the inflow hole 4b in the upper part of the outflow passage 4. Moreover, it has the molten glass induction | guidance | derivation surface 15a which guide | induces the molten glass G which reached | attained to the upper part of the roof 15 to the side part of the outflow passage 4. The molten glass guiding surface 15a has a first inclined plane 15aa that is inclined downward toward one side portion of the outflow passage 4, and a second inclination that is inclined downward toward the other side portion of the outflow passage 4. It consists of a plane 15ab. Specifically, the first inclined plane 15aa and the second inclined plane 15ab are in contact with each other at the top of the roof 15, and the roof 15 has a triangular cross-sectional shape. In addition, although the angle which 1st inclination plane 15aa and 2nd inclination plane 15ab comprise can be set arbitrarily, in this embodiment, it is 90 degrees. The roof 15 is also covered with platinum.

  Hereinafter, the behavior of the molten glass G flowing in the melting apparatus 1 will be described with reference to FIGS.

  2 is a front view showing the melting apparatus 1, FIG. 3 is a side view thereof, and FIG. 4 is a plan view thereof. In the region A subjected to cross hatching shown in FIG. 2 and FIG. 3, there is a molten glass G containing a heterogeneous substrate (foam or heterogeneous glass substrate). Among the molten glass G containing the heterogeneous substrate, the molten glass G positioned above the outlet 3 is melted along the side wall 2a of the melting furnace 2 as indicated by an arrow 10 in FIGS. 2 flows down and reaches the top (top) of the roof 15.

  After the flow is separated into two directions at the upper part (top) of the roof 15 and actively flows to the side of the outflow passage 4 by the first inclined plane 15aa and the second inclined plane 15ab. Further, it flows down to the bottom 2b of the melting furnace 2. For this reason, it is possible for the molten glass G containing the heterogeneous material to flow out of the melting furnace 2 and flow out of the melting furnace 2 by bypassing the outflow passage 4 along the upper portion of the outflow passage 4. Can be suppressed.

  At this time, as indicated by arrows 10b and 10c in FIG. 4, a part of the heterogeneous base material that has flowed down to the side of the outflow passage, and the heterogeneous base material that has reached the bottom 2b of the melting furnace 2 by the molten glass guiding surface 15a The part reaches the upstream end of the outflow passage 4 along the side portion of the outflow passage 4 and the bottom 2b of the melting furnace 2 adjacent to the side portion.

  However, since the inlet of the flow path 4a is blocked by the blocking plate 4c, it is possible to block the flow of the molten glass G that is about to flow into the flow path 4a as shown by the broken line in the figure. . Further, since the inflow hole 4b is formed in the upper part of the outflow passage 4, the molten glass G which is uniformly melted below the region A flows into the flow path 4a through the inflow hole 4b. The flow indicated by 11 occurs. For this reason, the rate at which the homogeneous molten glass G flows into the flow path 4a is increased, and the flow rate at which the molten glass G including the heterogeneous base material that reaches the upstream end of the outflow passage 4 flows into the flow path 4a is decreased. Will do. Thereby, it can suppress more effectively that a heterogeneous base material flows in into the outflow port 3, and flows out out of the melting furnace 2. FIG. In addition, since the outflow passage 4 is positioned upward from the bottom 2b of the melting furnace 2 by the base 5, the outflow passage 4 extends along the bottom 2b of the melting furnace 2 out of the molten glass G including the heterogeneous substrate. The effect of suppressing the molten glass G that bypasses the outflow of the melting furnace 2 further increases.

  Further, since the outflow passage 4 and the roof 15 are coated with platinum to improve the corrosion resistance, the outflow passage and outflow passage of the heterogeneous base caused by the erosion of the outflow passage 4 and the roof 15 are performed. 4 and the roof 15 can be prevented from being deformed.

  Further, according to this configuration, there is no need to separately provide a discharge passage or the like for positively discharging the heterogeneous substrate generated in the melting furnace 2 to the outside of the melting furnace 2, and the molten glass G in the melting furnace 2 is provided. Does not flow out of the melting furnace 2 from other than the outlet 3. For this reason, the supply amount of the molten glass G supplied from the melting furnace 2 to the outside of the melting furnace 2 does not decrease. As a result, it is possible to suitably prevent a decrease in product manufacturing efficiency and an increase in manufacturing cost.

  FIGS. 5A and 5B are perspective views showing a glass melting apparatus 1 according to the second and third embodiments of the present invention. In each drawing for explaining the glass melting apparatus according to the following second to fourth embodiments, components having the same function or shape as the glass melting apparatus 1 according to the first embodiment. Are omitted by overlapping with the same reference numerals. Further, in FIG. 5, the components other than the outflow port 3, the outflow passage 4, the base 5, and the roof 15 are not illustrated.

  The melting device 1 according to the second embodiment shown in FIG. 5A is different from the melting device 1 according to the first embodiment in that the molten glass guiding surface 15a is on one side of the outflow passage 4. This is a point that is an inclined plane inclined from the side portion toward the other side portion.

  Even with such a configuration, the molten glass G including the heterogeneous substrate can be guided to the side portion of the outflow passage 4 along the molten glass guiding surface 15a. The inclination direction in which the molten glass guiding surface 15a is inclined may be opposite to the direction shown in FIG.

  The melting device 1 according to the third embodiment shown in FIG. 5B is different from the melting device 1 according to the first embodiment in that the molten glass guiding surface 15a is from the upstream side of the outflow passage 4. This is a point that is an inclined plane that is inclined downward toward the side wall 2a.

  According to such a configuration, the molten glass G including the heterogeneous base material reaching the upper portion of the roof 15 is suppressed from flowing toward the upstream side of the outflow passage 4 along the roof 15. Then, the molten glass G is pushed out to the side of the outflow passage 4 by the subsequent molten glass G that sequentially flows down to the upper portion of the roof 15 and is guided to the side of the outflow passage 4. Become.

  FIG. 6 is a side view showing a glass melting apparatus 1 according to the fourth embodiment of the present invention. The melting device 1 is different from the melting device 1 according to the first embodiment in that the outflow passage 4 penetrates the side wall 2a of the melting furnace 2 (herein referred to as the first melting furnace 2X), This is a point connected to the second melting furnace 2Y located on the downstream side. The second melting furnace 2Y has the same configuration as the first melting furnace 2X except that the glass material C inlet 6 is not provided.

  According to such a structure, it can suppress that the heterogeneous base material which can generate | occur | produce in each of the 1st melting furnace 2X and the 2nd melting furnace 2Y flows out from the melting furnaces 2X and 2Y. Further, the heterogeneous substrate generated in the first melting furnace 2X is unlikely to flow out to the second melting furnace 2Y located on the downstream side.

  Here, the configuration of the glass melting apparatus according to the present invention is not limited to the melting apparatus according to each of the above embodiments. For example, in the melting apparatus 1 according to each of the embodiments described above, the cross-sectional shapes of the outlet 3 and the flow path 4a are rectangular, but may be circular, elliptical, or polygonal cross-sectional shapes.

  Furthermore, in each said embodiment, although the outflow port 3 and the outflow passage 4 exist in the position away from the bottom 2b of the melting furnace 2, the outflow port 3 is formed in the lower end part in the side wall 2a, The downstream end of the outflow passage 4 may be connected to the outflow port 3. In this case, the lower part of the outflow passage 4 may be constituted by the bottom 2b of the melting furnace 2. In this way, it is not necessary to separately provide a lower portion of the outflow passage 4, and the outflow passage 4 can be easily formed, so that the equipment cost can be reduced. In addition, in each said embodiment, although the outflow port 3 is provided in the side wall 2a of the melting furnace 2, you may provide the outflow port 3 in the bottom part 2b of the melting furnace 2. FIG. If the outflow port 3 is provided on either the side wall 2a or the bottom 2b adjacent to the side wall 2a, it is possible to prevent a region in which the molten glass G stagnates in the outflow passage 4 (flow path 4a). Moreover, you may form the outflow port 3 and the outflow channel | path 4 as an integral thing, without making it a different element.

  In addition, the outflow passage 4 protrudes perpendicularly from the side wall 2a of the melting furnace 2 into the melting furnace 2, but is not limited thereto, and may be protruded in an inclined state with respect to the side wall 2a. Moreover, the outflow port 3 and the outflow passage 4 do not necessarily need to be provided in the center part in the width direction of the melting furnace 2, and may be provided in a position shifted in the width direction from the center part. Moreover, although the outflow port 3 and the outflow channel | path 4 are provided in the side wall 2a used as the downstream end part of the melting furnace 2 in each said embodiment, you may provide in the side wall connected to the said side wall 2a. That is, the outflow port 3 and the outflow passage 4 may be provided so as to be substantially orthogonal to the illustrated direction.

  Furthermore, in each said embodiment, although the outflow channel 4 and the roof 15 are coat | covered with platinum, you may form with the alloy containing a platinum group element, molybdenum, etc.

  As a first embodiment of the present invention, using each glass melting apparatus shown in FIG. 7 (three examples and three comparative examples), the molten glass containing a heterogeneous substrate existing in the vicinity of the glass surface is discharged to the outlet. Numerical thermal fluid analysis was conducted on the inflow rate. In FIG. 7, the components of the melting device other than the outflow passage, the side wall, the bottom, and the roof are not shown.

  Hereinafter, conditions for performing the analysis will be described. The dimensions of the melting furnace for producing the molten glass are length: 20 m, width: 5 m, and height: 1 m. An outlet for letting the molten glass flow out of the melting furnace is provided at the lower end of the side wall that is the downstream end of the melting furnace. The dimensions of the outlet are width: 0.6 m and height: 0.35 m, and the dimensions of the flow path through which the molten glass flows are similar values. Moreover, the outflow passage protruding into the melting furnace shown in FIGS. 7C to 7F has a length of 1 m, and the cross-sectional shape of the outflow passage is the same as the outflow passage. Furthermore, the dimensions of the inflow hole shown in FIGS. 7 (e) and 7 (f) through which molten glass flows into the outflow passage at the upper end of the outflow passage are length: 0.5m and width: 0.6m. In addition, the upper end of the roof provided only in Examples 1 to 3 shown in FIGS. 7 (e), (f), and (g) is located at a height of 0.65 m from the bottom of the melting furnace, The apex angle of the roof is 90 °.

  In addition, the structure of Comparative Examples 1-3 is based on the conventional glass melting apparatus, and the comparative example 1 is a structure which has not taken any countermeasure about the outflow from the melting furnace of a heterogeneous base. Moreover, the comparative example 2 is a structure of the glass melting apparatus which concerns on the said patent document 1, Comprising: It has the structure which provided the plate which protrudes in a melting furnace from a side wall part above an outflow port. Furthermore, Comparative Example 3 is a configuration of the glass melting apparatus according to Patent Document 2 described above, and has a configuration in which an outflow passage protruding from the side wall portion into the melting furnace is provided, but an inflow hole and a roof are provided. This is different from the present invention in that it is not.

  The glass used was soda lime silica glass, and a glass raw material having a cullet rate of 50% was introduced into the upstream end of the melting furnace at a flow rate of 100 t / d. In order to accelerate the melting of the glass, in the region from the upstream end of the melting furnace to a position of 12 m, current heating is performed with a power of 1000 kW, the temperature of the glass surface at the center in the longitudinal direction of the melting furnace is 1500 ° C., the melting furnace The temperature of the glass surface on the side wall that becomes the downstream end of the glass was controlled to be 1400 ° C.

  Under the above conditions, after dividing the glass surface (line segment) at a position shifted to the upstream side by 1 m from the side wall of the melting furnace into 200 equal parts and tracking the trajectory of the flow from each equally divided point as a base point The percentage of each point flowing into the outlet was calculated as a percentage. Here, at the time of tracking the flow, the point where the flow headed upstream of the melting furnace away from the outlet and the outflow passage along the natural convection in the melting furnace was stopped and the tracking was stopped. Treated as not flowing.

The inflow rate under each condition obtained by analysis is shown below. Moreover, the arrows shown in FIGS. 7A to 7F schematically show typical flow trajectories under each condition.
Comparative Example 1 (FIG. 7 (a)): 33%
Comparative Example 2 (FIG. 7 (b)): 40%
Comparative Example 3 (FIG. 7 (c)): 29%
Example 1 (FIG. 7 (d)): 27%
Example 2 (FIG. 7 (e)): 13%
Example 3 (FIG. 7 (f)): 0%

  As described above, the inflow rate values in Examples 1 to 3 are all lower than those in Comparative Examples 1 to 3. In the embodiment of the present invention, the roof that covers at least a part of the upper portion of the outflow passage that continues from the side wall side of the melting furnace is composed of an inclined plane that is inclined downward toward the side of the outflow passage. It is assumed that by having the molten glass guiding surface, it was possible to suppress that the molten glass including the heterogeneous base material bypasses the outflow passage along the upper portion of the outflow passage. In addition, since the inflow hole is formed in the upper part of the outflow passage, the molten glass melted homogeneously below the glass surface to the outflow passage through the inflow hole as compared with the molten glass containing the heterogeneous substrate. It is assumed that the rate of inflow increased.

  As a second example of the present invention, using the glass melting apparatus shown in FIG. 8 (three examples and three comparative examples), the heterogeneous substrate existing in the vicinity of the glass surface was included as in the first example. Numerical thermal fluid analysis was performed on the ratio of molten glass flowing into the outlet. In FIG. 8, the components of the melting device other than the outflow passage, the side wall, the bottom, the base, and the roof are not shown.

  Hereinafter, conditions for performing the analysis will be described. The second embodiment differs from the first embodiment in that the outlet provided at the downstream end of the melting furnace is located away from the bottom of the melting furnace. A base for supporting the outflow passage is provided, and the outflow passage is located upwardly away from the bottom of the melting furnace like the outflow port by the base. Thereby, the height of the melting furnace is 1.25 m, the height from the bottom of the melting furnace to the lower end of the outlet and the outflow passage is 0.25 m, and the roof provided only in Examples 1 to 3 The upper end is located at a height of 0.9 m from the bottom of the melting furnace. Other implementation conditions are the same as those in the first embodiment.

The inflow rate under each condition obtained by analysis is shown below. Also, the arrows shown in FIGS. 8A to 8F schematically show typical flow trajectories under each condition.
Comparative Example 1 (FIG. 8 (a)): 17%
Comparative Example 2 (FIG. 8 (b)): 21%
Comparative Example 3 (FIG. 8 (c)): 11%
Example 1 (FIG. 8 (d)): 7%
Example 2 (FIG. 8 (e)): 2%
Example 3 (FIG. 8 (f)): 0%

  As described above, the inflow rate values in Examples 1 to 3 are all lower than those in Comparative Examples 1 to 3. This is presumably because the same effect as in the first embodiment was obtained also in the second embodiment.

  As a result of the above, according to the present invention, it is presumed that the molten glass near the glass surface containing the heterogeneous substrate can be suppressed as much as possible from flowing into the outlet and out of the melting furnace. Can do.

DESCRIPTION OF SYMBOLS 1 Glass melting apparatus 2 Melting furnace 2X 1st melting furnace 2Y 2nd melting furnace 2a Side wall 2b Bottom part 3 Outlet 4 Outflow passage 4a Channel 4b Inflow hole 4c Sealing plate 5 Base G Molten glass S Glass surface 6 Inlet 7 Glass Convection of substrate 8 Convection of glass substrate 9 Convection of glass substrate 10 Convection of glass substrate 10b Flow of heterogeneous substrate bypassing the side of the outflow passage and the bottom of the melting furnace adjacent to the side 10c Flow of heterogeneous substrate guided to bottom 2 11 Flow of homogeneous molten glass 15 Roof 15a Molten glass guiding surface 15aa First inclined plane 15ab Second inclined plane A Region including heterogeneous substrate C Glass raw material

Claims (13)

A glass melting apparatus comprising: a melting furnace that generates or heats molten glass; and an outflow passage that protrudes into the melting furnace from a downstream side wall of the melting furnace and has an inlet hole for the molten glass. There,
A roof covering at least a part of the upper portion of the outflow passage that is continuous from the side wall side of the melting furnace;
The glass melting apparatus, wherein the roof has a molten glass guiding surface formed of an inclined plane that is inclined downward toward a side portion or the side wall of the outflow passage. The molten glass guiding surface is
A first inclined plane having a downward slope toward one side of the outflow passage;
The glass melting apparatus according to claim 1, further comprising: a second inclined plane having a downward slope toward the other side portion of the outflow passage.   The glass melting apparatus according to claim 2, wherein the first inclined plane and the second inclined plane are in contact with each other to form a top portion of the roof.   The inflow hole is opened at an upper portion separated from the bottom of the melting furnace in a passage constituting wall that divides the inside and outside of the outflow passage, and is formed at the top of the outflow passage on the tip side from the roof. The glass melting apparatus according to any one of claims 1 to 3.   5. The glass melting apparatus according to claim 4, wherein the inflow hole is formed at a front end side end portion in an upper portion of the outflow passage.   6. The glass melting apparatus according to claim 1, wherein the roof extends from a side wall of the melting furnace to an edge of the inflow hole at an upper portion of the outflow passage.   The glass melting apparatus according to any one of claims 1 to 6, wherein a tip portion of the outflow passage is sealed.   The glass melting apparatus according to any one of claims 1 to 7, wherein the entire outflow passage is located away from the bottom of the melting furnace.   The glass melting apparatus according to any one of claims 1 to 7, wherein a lower part of a passage constituting wall of the outflow passage is constituted by a bottom portion of the melting furnace.   The molten glass according to any one of claims 1 to 9, wherein a part or the whole of the outflow passage and the roof is formed of a platinum group element, an alloy containing the platinum group element, or molybdenum. apparatus.   A plurality of melting furnaces, each having a connecting portion for connecting adjacent melting furnaces, wherein at least one of the connecting portions is constituted by the outflow passage, and the roof covers the upper portion of the outflow passage. The glass melting apparatus according to claim 1, wherein A method for supplying molten glass, wherein molten glass produced or heated in a melting furnace is caused to flow out from an outflow passage projecting into the melting furnace from a downstream side wall of the melting furnace and to be supplied to the outside of the melting furnace. ,
The outflow passage includes a roof that covers at least a part of the upper portion of the outflow passage that is continuous from the side wall side of the melting furnace,
The method for supplying molten glass, wherein the roof has a molten glass guiding surface comprising an inclined flat surface that is inclined downward toward a side portion or the side wall of the outflow passage. An outflow passage for a melting furnace provided in the melting furnace in order to flow out the molten glass,
A roof covering at least a part of the upper portion of the outflow passage that is continuous from one end of the outflow passage,
An outflow passage for a melting furnace, wherein the roof has a molten glass guiding surface formed of an inclined flat surface that is inclined downward toward a side portion of the outflow passage or toward the one end side.

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