JP3724153B2 - Vacuum degassing equipment for molten glass - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of a vacuum degassing apparatus for molten glass that removes bubbles from continuously supplied molten glass.
[0002]
[Prior art]
Conventionally, in order to improve the quality of a molded glass product, a vacuum degassing apparatus that removes bubbles generated in the molten glass before the molten glass melted in the melting furnace is molded by a molding apparatus has been used. . FIG. 3 shows an example of a possible arrangement when a conventional vacuum degassing apparatus is applied between a dissolution tank and a working tank, and FIG. 4 shows a vacuum degassing apparatus shown in FIG. The figure which cut | disconnected by the IV line and expand | deployed is shown.
As shown in FIG. 3, the conventional vacuum degassing apparatus 100 performs vacuum degassing treatment on the molten glass G in the melting tank 102 to work on a processing tank 114, for example, a processing tank or a bottle for a plate material such as a float bath. It is used for the process of continuously supplying to the tank, and is provided so that the dissolution tank 102 and the work tank 114 are connected linearly at the center. As shown in FIG. 4, the vacuum degassing apparatus 100 includes a vacuum vacuum degassing tank 106 horizontally in a vacuum suction housing 104 that is sucked in vacuum, and a rising pipe 108 and a lowering pipe 110 that are vertically installed near both ends thereof. The storage is arranged.
[0003]
The ascending pipe 108 communicates with the vacuum degassing tank 106 to raise the molten glass G before the defoaming treatment from the melting tank 102 and introduce it into the vacuum degassing tank 106. The downcomer 110 communicates with the vacuum degassing tank 106, and lowers the molten glass G after the defoaming process from the vacuum degassing tank 106 to the work tank 114. In the housing 104, a heat insulating material 112 such as a heat insulating brick is provided around the vacuum degassing tank 106, the ascending pipe 108, and the descending pipe 110. The decompression housing 104 is made of metal, for example, stainless steel, and is vacuumed from the outside by a vacuum pump (not shown) or the like, the inside is decompressed, and the inside of the decompression deaeration tank 106 is set to a predetermined decompression. For example, the pressure is maintained at a reduced pressure of 1/20 to 1/3 atm.
[0004]
Since the conventional vacuum degassing apparatus 100 is configured to process a molten glass G at a high temperature, for example, 1200 to 1400 ° C., it is disclosed in Japanese Patent Application Laid-Open No. 2-221129 relating to the application of the present applicant. As shown in the drawing, the portions that are in direct contact with the molten glass G, such as the vacuum degassing vessel 106, the rising pipe 108, and the downfalling pipe 110, are usually circular tubes made of noble metal such as platinum or a platinum alloy such as platinum rhodium. It is configured. The present applicant has put a vacuum degassing apparatus into practical use by using a platinum alloy circular tube.
Here, these are constituted by noble metal circular tubes such as platinum alloys because not only the molten glass G is hot, but also the noble metal has low high temperature reactivity with the molten glass and is inhomogeneous due to reaction with the molten glass. This is because the strength at a high temperature can be secured to some extent without causing any deterioration.
In particular, the vacuum defoaming tank 106 is composed of a noble metal circular tube, in addition to the above reasons, a current is passed through the noble metal circular tube itself to cause self-heating to uniformly heat and melt the molten glass G in the cylinder. This is to keep the temperature of the glass G at a predetermined temperature.
[0005]
[Problems to be solved by the invention]
By the way, when the vacuum degassing tank 106 is made of a noble metal, it is preferable to use a circular tube from the viewpoint of high temperature strength. However, since noble metals such as platinum are expensive, the thickness cannot be increased . Therefore, there is a limit to the diameter of the circular tube in terms of both cost and strength, the diameter of the circular tube cannot be increased so much, and the flow rate of the molten glass G that can be defoamed in the vacuum degassing tank 106 is also limited. There was a problem that it was not possible to construct a vacuum degassing apparatus with a large flow rate.
[0006]
For such a problem, it is also conceivable to increase the defoaming amount by increasing the overall length of the tubular vacuum degassing tank 106 to increase the flow velocity. However, there is a problem that the apparatus becomes longer than the processing amount and compared to the dissolution tank 102, the working tank 114, and the like. For this reason, it is necessary to change the positional relationship between the dissolution tank 102 and the work tank 114 that are already used in the arrangement as shown in FIG. 3, and there is a problem that existing facilities cannot be effectively used.
Furthermore, if the vacuum degassing tank is linearly long, the amount of expansion of the vacuum degassing tank 106 due to heating increases proportionally, and the distance between the centers of the ascending pipe 108 and the descending pipe 110 is shifted. There is also a problem that the safety of the apparatus may be impaired, such as distortion of the apparatus.
[0007]
By the way, when the molten glass G is soda-lime glass, since the viscosity is lower than that of other glasses such as borosilicate glass, it is possible to set the degree of vacuum of the vacuum degassing tank low. For this reason, it is possible to reduce the height of the vacuum degassing apparatus (for example, 2 to 3 m) according to the degree of vacuum of the vacuum degassing tank, and to reduce the height of the vacuum degassing apparatus. It is done.
[0008]
However, if it is actually applied to existing equipment, the following inconvenience occurs. That is, in FIG. 3, in the conventional kiln, the melting tank 102 and the working tank 114 are communicated with molten glass by a connecting portion such as a throat (not shown), but the length is 2 to 4 m at most. . During this time, if the riser downcomer pipe is to be installed, the length of the vacuum degassing tank provided on the upper part thereof becomes extremely short, and the residence time for expanding and floating the bubbles in the molten glass during the decompression is increased. It becomes difficult to secure. That is, in order for the bubbles that have expanded and floated under reduced pressure to burst and disappear on the surface of the molten glass, a certain surface area in contact with the reduced pressure gas phase is required in the reduced pressure tank, but this area cannot be secured. Of course, if the vacuum tank 100 is short in the length direction and wide in the width direction, only the area can be secured, but the streamline of the molten glass becomes uneven in the width direction, and the glass near the center in the width direction is short-circuited and insufficiently clarified. It is easily inferred that the downcomer will be reached and bubbles will be produced in the product. Furthermore, the melting tank 102 and the work tank 114 are covered with a brick structure called Osako, and the decompression tank overlaps with the Osako brick, making it extremely difficult to actually construct equipment. There is a risk that it cannot be installed. In order to avoid such a situation, the vacuum degassing tank 106 must be set apart from the dissolution tank 102 to some extent. As a result, the space cannot be made sufficiently small, and it is already installed and used. It is necessary to change the positional relationship between the dissolving tank 102 and the working tank 114, and there is a problem that the existing equipment cannot be used effectively.
[0009]
An object of the present invention is to solve the problems of the prior art, and to process a large amount of molten glass in a vacuum degassing apparatus for molten glass that removes bubbles from continuously supplied molten glass. It is possible to provide a vacuum degassing apparatus for molten glass, which is excellent in safety of the apparatus and can effectively use existing equipment.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a vacuum housing that is evacuated, a vacuum defoaming tank that is provided in the vacuum housing and degassed molten glass, and communicates with the vacuum degassing tank. And introducing means for introducing molten glass before vacuum degassing into the vacuum degassing tank; and communicating with the vacuum degassing tank; and providing the molten glass after vacuum degassing from the vacuum degassing tank Deriving means for deriving, wherein the vacuum degassing tank and the vacuum housing around the vacuum degassing tank are formed in a U-shape in the horizontal direction. Providing equipment.
[0011]
Here, the introduction means is a riser pipe that raises the molten glass before vacuum degassing and introduces it into the vacuum degassing tank, and the derivation means lowers the molten glass after vacuum degassing and lowers the pressure reduction It is preferable that it is a downcomer pipe | tube derived | led-out from a defoaming tank.
Moreover, it is preferable that the vacuum degassing tank is formed of an electroformed refractory at least at a portion that directly contacts the molten glass.
Furthermore, the molten glass is preferably soda lime glass.
[0012]
Moreover, this invention provides the vacuum degassing apparatus of the molten glass which has two said vacuum degassing apparatuses of the molten glass in parallel.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the vacuum degassing apparatus of the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.
[0014]
In FIG. 1, the schematic sectional drawing of an example which applied the vacuum degassing apparatus of this invention between the dissolution tank and the working tank is shown.
A vacuum degassing apparatus 10 (hereinafter, referred to as a vacuum degassing apparatus 10) shown in FIG. 1 is continuously connected to a work tank 50 that performs vacuum degassing treatment on the molten glass G in the melting tank 20 to form bottles and the like. The first vacuum degassing device 11 (hereinafter referred to as first vacuum degassing unit 11) and the second vacuum degassing device 12 (hereinafter referred to as second vacuum degassing). Part 12).
[0015]
Here, as described above, in the conventional vacuum degassing apparatus in which the vacuum degassing tank is constituted by a precious metal circular tube, a large-flow vacuum degassing apparatus cannot be constructed in terms of both cost and strength. Even when the total length of the defoaming tank is increased and the flow rate is increased to increase the amount of defoaming, the apparatus becomes longer and there is a problem that the existing equipment cannot be used effectively. There is also a problem that the safety of the apparatus may be impaired, for example, the expansion of the vacuum degassing tank accompanying heating causes the center distance between the ascending pipe and the descending pipe to be shifted to cause distortion in the apparatus. Furthermore, if the molten glass is soda-lime glass, the height of the vacuum degassing device can be reduced, but it will be necessary to change the positional relationship of each existing device, and the existing equipment must still be used effectively. There is a problem that can not be.
[0016]
Therefore, as shown in FIG. 1, the vacuum degassing apparatus of the present invention has a U-shaped vacuum defoaming tank 14, 15 and a vacuum housing 13 covering the periphery of the vacuum degassing tank 14, 15 in the horizontal direction. The above-mentioned problem is solved by forming the film. That is, by forming such a U-shape, it is possible to ensure a long overall length of the vacuum degassing tanks 14 and 15 while being compact, so that the amount of defoaming treatment is greatly increased by appropriately increasing the flow rate. It becomes possible to make it. Moreover, since the distance between the cores of the ascending pipe 16 and the descending pipe 18 can be freely set, for example, the distance and direction between the dissolution tank 20 and the working tank 50 are changed with respect to the existing equipment. It becomes possible to apply as it is without doing.
[0017]
Further, the thermal expansion of the vacuum degassing tanks 14 and 15 and the surrounding insulating bricks 32 is allowed to escape in a U-shaped protruding direction, that is, a direction perpendicular to the center line connecting the rising pipe 16 and the lowering pipe 18. Therefore, the deviation of the distance between the cores of the ascending pipe 16 and the descending pipe 18 can be greatly reduced, the apparatus can be sufficiently prevented from being distorted by thermal expansion, and the safety of the apparatus can be improved.
Furthermore, even when the height of the apparatus is lowered, it can be provided so as to avoid the roof (not shown) of the dissolution tank 20 and the work tank 50, so that the existing equipment is not changed. The vacuum degassing apparatus of the present invention can be applied.
[0018]
FIG. 2 shows a developed view of the first vacuum degassing unit 11 of the vacuum degassing apparatus 10 shown in FIG. 1 cut along line II-II.
The first vacuum degassing unit 11 and the second vacuum degassing unit 12 are basically configured in the same manner except that they are symmetrical with each other. Therefore, the first vacuum degassing unit 11 will be mainly described below. The description of the second vacuum degassing unit 12 is basically omitted.
[0019]
As shown in the figure, the first vacuum degassing part 11 includes a vacuum housing 13, a vacuum degassing tank 14, an ascending pipe 16, and a descending pipe 18.
The decompression housing 13 is for ensuring the airtightness of the decompression defoaming tank 14, and its upper portion 13c is formed in a U-shape in the horizontal direction, and the leg portions 13a, 13b are downward from the vicinity of both ends of the U-shape. Protrusively formed. Therefore, the cross-sectional shape taken along the line II-II in FIG. 1 has a substantially portal shape as shown in FIG. The material and structure of the decompression housing 13 are not particularly limited as long as the decompression housing 13 has airtightness and strength required for the decompression defoaming tank 14, but is made of metal, particularly stainless steel. Is preferred. Such a decompression housing 13 is vacuum-sucked by a vacuum pump (not shown) or the like from the outside, the inside is decompressed, and a predetermined decompression, for example, 1/20 to 1 / It is configured to maintain a reduced pressure of 3 atm.
[0020]
A U-shaped vacuum degassing tank 14 is provided in the upper portion 13 c of the vacuum housing 13. Further, an ascending pipe 16 is communicated with the vicinity of the left end of the vacuum degassing tank 14, and a descending pipe 18 is communicated with the vicinity of the right end of the vacuum degassing tank 14. The ascending pipe 16 and the descending pipe 18 are respectively disposed in the legs of the decompression housing 13.
[0021]
In the vacuum degassing apparatus 10 of the present invention, the materials of the vacuum degassing tank 14, the rising pipe 16 and the descending pipe 18 are not particularly limited, and examples include noble metal alloys such as platinum or platinum alloys, electrocast refractories, and the like. However, among these, it is preferable to use an electroformed refractory. That is, by forming the main portion that is in direct contact with the molten glass G in the vacuum degassing apparatus 10 with an electroformed refractory, the cost is significantly reduced as compared with a conventionally used platinum alloy-made one. Since it is possible to design in a free shape and a free thickness, it is possible to increase the capacity of the vacuum degassing apparatus 10 and to perform vacuum degassing at a higher temperature. It is.
[0022]
Even when an electroformed refractory is used, it is the lower end of the riser pipe 16 that is immersed in the molten glass G in the pit 22 or the lower end of the downcomer pipe 18 and is melted in the pit 52. As for the part immersed in the glass G, since there is an interface between the molten glass G and the atmosphere in particular, there is a high reactivity in the vicinity of this interface. In particular, in the case of electroformed refractories, the interface part and joint part deteriorate. Cheap. Therefore, it is preferable that the lower end portion of the rising pipe 16 and the lower end portion of the down pipe 18 are made of platinum or a platinum alloy.
[0023]
The electrocast refractory is not particularly limited as long as it is a brick that is obtained by electrically melting a refractory raw material and then cast into a predetermined shape, and various conventionally known electrocast refractories may be used. Among these, alumina-based electrocast refractories, zirconia-based electrocast refractories, AZS-based electrocast refractories and the like are preferable examples because they have high corrosion resistance and little foaming from the substrate. Specifically, marsnite (MB-G), ZB-X950, zirconite (ZB) (all manufactured by Asahi Glass Co., Ltd.) and the like.
[0024]
The shape of the vacuum degassing tank 14 is not particularly limited as long as it is a cylindrical body formed in a U shape in at least the horizontal direction as described above, and the shapes of the ascending pipe 16 and the descending pipe 18 are at least cylindrical. If it does not specifically limit. Therefore, the cross-sectional shapes of the vacuum degassing tank 14, the ascending pipe 16, and the descending pipe 18 may be not only circular but also rectangular.
Moreover, when constructing the decompression defoaming tank 14, the riser pipe 16, and the downfall pipe 18 using electroformed bricks, the method is not particularly limited, and for example, relatively small rectangular parallelepiped electroformed bricks may be stacked. Alternatively, cylindrical electroformed bricks cast and formed into a cylindrical shape or a rectangular tube shape may be stacked in a row, and the joint portion between them may be filled with a joint material to form a cylindrical tube having a predetermined length.
[0025]
The installation position of the riser pipe 16 is not particularly limited as long as the molten glass G can be introduced from the melting tank 20. For example, as shown in FIG. 1, pits 22 are formed on the left and right sides of the melting tank 20. In such a case, it is preferable to insert the lower end of the ascending pipe 16 into the pit 22 and immerse it in the molten glass G because existing equipment can be used effectively.
On the other hand, the position where the downcomer 18 is installed is not particularly limited as long as it is a position where the molten glass G can be led out to the work tank 50. For example, as shown in FIG. The lower end of the downcomer pipe 16 may be inserted into the pit 52 and immersed in the molten glass G.
[0026]
A heat insulating brick 32 (hereinafter referred to as a heat insulating brick 32) covering the vacuum defoaming tank 14 is disposed around the vacuum degassing tank 14, and the rise pipe 16 and the down pipe 18 are respectively surrounded by the bricks. A heat insulating brick 32 is disposed to cover the surface.
As the heat insulating brick 32, known various bricks may be used and are not particularly limited. The heat-insulating bricks 32 arranged in this way are accommodated in the decompression housing 13 by covering the outside with the decompression housing 13. Note that the temperature outside the decompression housing 13 is preferably as low as possible, preferably about 200 ° C. or less, for example, about 100 ° C. by blocking heat transmitted to the decompression housing 13 by the heat insulating brick 32 as much as possible.
[0027]
Moreover, it is good also as a structure which can provide a heating heater with the heat insulation brick 32 around the decompression degassing tank 14, the riser pipe 16, and the downfall pipe 18 as needed, and it can let cooling water pass through. It is good also as a structure which can be cooled.
[0028]
The molten glass G that has been subjected to the vacuum degassing process by the vacuum degassing units 11 and 12 reaches the work tank 50 via the downcomers 18 and 19 and the pits 52 and 52.
The working tank 50 in the illustrated example is a part for forming a bottle, and the plane is generally formed in a half-moon shape, and a plurality (for example, 3 to 5) of forehearths 54 are radially provided from the working tank 50. .
[0029]
The working tank 50 is not particularly limited as long as it is various types of processing tanks for performing processing such as stirring and forming of the molten glass G, not only for forming the bottle in the illustrated example. For example, when the work tank 50 is a plate material forming treatment tank, the work tank 50 is formed in a rectangular shape, and one or two canals are provided in parallel from the work tank. In any case, glass products such as bottles and plate glass are manufactured in the fore hearth 54 and the canal.
[0030]
A stirring device that joins and stirs the molten glass G supplied from the two vacuum degassing units 11 and 12 may be provided on the downstream side of the downcomers 18 and 19 and in the work tank 50. .
As the stirring device, various known stirring devices used for stirring molten glass may be used, and the stirring device is not particularly limited. For example, the stirring device includes a stirring tank for securing a space for stirring the molten glass G, a stirrer that is contained in the stirring tank and that stirs the molten glass G, and a drive motor that rotationally drives the stirrer. May be configured. By having such a stirrer, the molten glass G supplied from the two downcomers 18 and 19 can be forcibly stirred and homogenized, so that a glass having superior optical characteristics can be obtained. Can do.
[0031]
Here, the molten glass G to be processed by the vacuum degassing apparatus 10 of the present invention is not particularly limited, and examples thereof include soda lime glass and borosilicate glass. Since the apparatus 10 can process a large amount of molten glass, it is preferable to process soda-lime glass that requires a large amount of processing. In addition, by making soda lime glass a treatment target, it becomes possible to set the degree of vacuum of the vacuum degassing tank 14 low, coupled with the U-shaped shape of the vacuum degassing part 14 according to the present invention, The height of the vacuum degassing tank 14 can be lowered (for example, 2 to 3 m). Accordingly, it is possible to make the height compact while effectively utilizing existing equipment.
[0032]
By the way, since the vacuum degassing apparatus 10 of the illustrated example is a parallel type having a first vacuum degassing part 11 and a second vacuum degassing part 12, these two vacuum degassing parts 11 and 12 perform vacuum degassing. Bubble processing will be performed. Therefore, a further large amount of the molten glass G under reduced pressure defoaming can be performed, and a flexible response such as operating only one of the reduced pressure defoaming sections 11 or 12 can be made even with respect to fluctuations in the production amount. .
In particular, as shown in FIG. 1, if the molten glass G is evenly led out from the left and right pits 22, 22 of the melting tank 20, the molten glass G flows in either the left or right direction in the melting tank 20. Therefore, it is possible to prevent the occurrence of non-uniform convection and thus obtain a molten glass having better homogeneity.
[0033]
Further, vacuum one degassing unit 11 or 12, even if Tsu Do unavailable for maintenance or the like, the other of the vacuum degassing unit 11 or 12 can continue to be used alone, the manufacture of glass products Can be minimized. In particular, if the vacuum degassing tank 14, the riser pipe 16, the downfall pipe 18 and the like are made of platinum or a platinum alloy, even if they are damaged and it takes several months to repair them, either the vacuum degassing part 11 or It is extremely effective because it can be operated with only 12.
[0034]
Note that the vacuum degassing apparatus of the present invention is not limited to the parallel type in the illustrated example, and may be configured by only one of the first vacuum degassing part 11 or the second vacuum degassing part 12. It is. In this case, it is good also as a structure which provides a vacuum degassing apparatus so that any one side part of the dissolution tank 20 and the working tank 50 may be connected like the case of FIG. It is good also as a structure which provides a vacuum degassing apparatus so that the center part of the work tank 50 may be connected. Moreover, it is good also as a structure which arrange | positions at least one of the dissolution tank 20 and the working tank 50 linearly along the direction of the edge part of the pressure reduction degassing tank 14. FIG. In any case, the above-described effect of the present invention can be sufficiently obtained even in such a single vacuum degassing apparatus.
[0035]
An example of a process in which the molten glass G is defoamed with the vacuum degassing apparatus 10 of the present invention and continuously supplied to the next processing furnace will be described below. In addition, since the 1st vacuum degassing part 11 and the 2nd vacuum degassing part 12 are comprised similarly, the effect | action about the vacuum degassing part 12 is mainly demonstrated below.
First, in the melting tank 20, the glass is melted to obtain a molten glass G. The temperature at this time is 1250 to 1450 ° C., preferably 1280 to 1320 ° C. in the case of soda-lime glass. Within this range, the viscosity of the molten glass G can be made sufficiently small, an efficient vacuum degassing treatment can be performed, and deterioration of the apparatus (particularly platinum or platinum alloy) can be suppressed. In addition, about glass of other compositions, such as a borosilicate glass, it is preferable to fuse | melt at the temperature which becomes the same viscosity as the said soda-lime glass.
[0036]
And the inside of the pressure reduction housing 13 and the pressure reduction deaeration tank 14 are maintained in a vacuum suction state by a vacuum pump (not shown). In this state, the glass G which has been molten in the melting vessel 20 is introduced to rise through the riser 16 through the pits 2 2 in the vacuum degassing vessel 14, the molten glass G is in the vacuum degassing vessel 14 Defoaming is performed under reduced pressure conditions.
[0037]
Next, the defoamed molten glass G is led to the work tank 50 through the downcomer 18 and the pit 52.
In addition, since the vacuum degassing apparatus 10 of the example of illustration is the 2 structure of the 1st vacuum degassing part 11 and the 2nd vacuum degassing part 12, the molten glass G is each a vacuum degassing with two risers. It is supplied to the tank, discharged from the two downcomers, and supplied to the work tank 50.
[0038]
By the way, the vacuum degassing apparatus for molten glass of the present invention is not limited to the siphon type vacuum degassing apparatus shown in FIG. 2, but also the horizontal vacuum degassing apparatus shown in JP-A-5-262530 and JP-A-7-291633. Of course, it may also be applied to the foam device.
As mentioned above, although the vacuum degassing apparatus of the molten glass of this invention was demonstrated in detail, this invention is not limited to the said Example, You may perform various improvement and change in the range which does not deviate from the summary of this invention. Of course.
[0039]
【The invention's effect】
As described above in detail, according to the present invention, a large amount of molten glass can be processed in a vacuum degassing apparatus for molten glass that removes bubbles from continuously supplied molten glass. As well as being excellent in safety, existing facilities can be used effectively.
In addition, if it is configured as a parallel-type vacuum degassing device, the processing flow rate can be further increased, and it is possible to flexibly respond to fluctuations in production volume, and it is possible to obtain molten glass with better homogeneity. It becomes.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing an example in which the vacuum degassing apparatus of the present invention is applied between a dissolution tank and a working tank.
FIG. 2 is a cross-sectional view of the vacuum degassing part shown in FIG. 1 developed by cutting along a line II-II.
FIG. 3 is a schematic plan view showing an example in which a conventional vacuum degassing apparatus is applied between a dissolution tank and a working tank.
4 is a cross-sectional view in which a vacuum degassing part in the vacuum degassing apparatus shown in FIG. 3 is developed by cutting along line IV-IV.
[Explanation of symbols]
10 parallel-type vacuum degassing apparatus 11 first vacuum degassing apparatus (first vacuum degassing part)
12 2nd vacuum degassing apparatus (2nd vacuum degassing part)
13 Vacuum housing
13a, 13b Decompression housing leg
13c Upper part of decompression housing 14, 15 Depressurization defoaming tank 16 Rising pipe 18, 19 Lowering pipe 20 Dissolution tank 22 Pit 32 Insulating brick 50 Work tank 52 Pit 54 Fore Haas
100 Vacuum degassing equipment
102 Dissolution tank
104 decompression housing
106 vacuum degassing tank
108 riser
110 Downcomer
112 Thermal insulation
114 Working tank

Claims (5)

A vacuum housing that is vacuumed;
A vacuum degassing tank that is provided in the vacuum housing and performs vacuum degassing of the molten glass;
An introduction means that is provided in communication with the vacuum degassing tank and introduces the molten glass before the vacuum degassing into the vacuum degassing tank;
Provided in communication with the vacuum degassing tank, and having a deriving means for deriving the molten glass after the vacuum degassing from the vacuum degassing tank,
The vacuum degassing apparatus for molten glass, wherein the vacuum degassing tank and the vacuum housing around the vacuum degassing tank are formed in a U-shape in the horizontal direction. The introduction means is a riser pipe that raises the molten glass before the vacuum degassing and introduces it into the vacuum degassing tank, and the derivation means lowers the molten glass after the vacuum degassing and lowers the vacuum degassing tank. The vacuum degassing apparatus for molten glass according to claim 1, which is a downcomer derived from 3. The vacuum degassing apparatus for molten glass according to claim 1, wherein at least a portion of the vacuum degassing tank that is in direct contact with the molten glass is formed of an electroformed refractory. The said molten glass is soda-lime glass, The vacuum degassing apparatus of the molten glass of any one of Claims 1-3. The vacuum degassing apparatus of the molten glass which has two the vacuum degassing apparatuses of the molten glass of any one of Claims 1-4 in parallel.

Images