JP2015098425A - Hanger assembly and production apparatus for float plate glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hanger assembly which withstands high heat in molding molten glass and causes less fusion and no fracture.SOLUTION: A hanger assembly is provided in a float bath apparatus including a float bath for a float plate glass production apparatus and a float bath roof arranged above the float bath and is used to hang refractory bricks constituting the ceiling part of the float bath roof. The hanger assembly includes a support rod made of an NiCr alloy, SiC-made hanger members and a connection pin for engaging the support rod with the hanger members. The connection pin is composed of a SiN-made sintered body in which a plurality of SiNparticles are bonded in the crystalline grain boundary layer.

Description

  The present invention relates to a hanger assembly and an apparatus for manufacturing a float glass plate including the hanger assembly.

The production of plate glass by the float process is generally performed by the method described below. After the glass raw material is heated and melted to obtain molten glass, the molten glass is continuously supplied onto the surface of a molten metal such as molten tin accommodated in a bathtub.
A glass ribbon is formed while conveying the molten glass along the surface of the molten metal from the upstream side to the downstream side. The glass ribbon is pulled out of the bathtub, slowly cooled, washed, and then cut. A plate glass can be obtained.
This plate glass manufacturing method by float forming has high productivity, and the obtained plate glass is excellent in flatness. Therefore, plate glass by float forming is widely applied as plate glass for construction, plate glass for automobiles, plate glass for FPD (flat panel display) and the like.

FIG. 8 is a cross-sectional view showing an example of a manufacturing apparatus used when the float method is performed. The main configuration of the manufacturing apparatus shown in FIG. 8 is generally well known, as described in Patent Document 1 below.
The manufacturing apparatus 100 shown in FIG. 8 includes a ceiling portion called a float bath 101 and a float bath roof 102. In the float bath 101, a molten metal 105 is accommodated in a bathtub 103, and a molten glass G is supplied thereon. The float bath roof 102 includes a side wall 106, a metal roof casing 107 installed on the side wall 106, a horizontal member 108 installed inside the roof casing 107, and a ceiling portion 109 supported by being suspended by the horizontal member 108. It has.
The ceiling portion 109 is an assembly of a plurality of roof bricks, and the ceiling portion 109 is supported by supporting these roof bricks with a plurality of hook-type hanger assemblies 110.

  A plurality of heaters 111 are suspended from the ceiling portion 109, and the molten glass G on the molten metal 105 can be adjusted to a desired temperature by these heaters 111. The space above the molten glass G is a reducing atmosphere composed of nitrogen gas and hydrogen gas supplied from the outside of the roof casing 107 through a gas supply pipe.

  As shown in FIG. 9, Patent Document 1 or Patent Document 2 describes a hanger assembly 110 for suspending and supporting a roof brick 109 </ b> A constituting a ceiling portion 109. The hanger assembly 110 includes an extending portion 113 shown in FIG. 9 suspended from the horizontal member 108, a bifurcated support piece 115 formed at the lower end of the extending portion 113, and a pin attached to the support piece 115. And a hook member 117 joined through 116. An inverted T-shaped flange 117A is formed at the lower end of the hook member 117, and the ceiling 109 is supported by supporting the corner portion of the roof brick 109A that constitutes the ceiling 109 using the flange 117A. Can be supported.

International Publication No. 2010/150831 International Publication No. 2011/010622

In the hanger assembly 110 shown in FIG. 9, the lower end side of the hook member 117 is located on the lower surface side of the ceiling portion 109 and is disposed on the side facing the molten glass G. It is exposed to temperatures of 1000 ° C or over 1000 ° C.
Therefore, in the hanger assembly 110, the hook member 117 is less heat-resistant than a ceramic material, for example, an Al ₂ O ₃ sintered body in a ceramic material, which is less deteriorated in strength even when exposed to temperatures exceeding 1000 ° C. It is composed of SiC that is recognized as having excellent heat resistance. Similarly, the pin 116 inserted into the upper end of the hook member 117 is also made of SiC because there is a demand for higher heat resistance.
In addition, the hanger assembly 110 that supports the ceiling portion 109 depends on the size of the float bath 101, but about several thousand pieces are required for a large apparatus. The piece 115 is made of a NiCr heat resistant alloy.

In recent years, performance of plate glass for FPD and the like has been remarkably improved, and in the production of high strain point glass such as alkali-free glass, the molding temperature may be 100 ° C. or more higher than that of conventional soda lime glass. For this reason, depending on the type of glass to be molded, the hook member 117 is exposed to a temperature of 1000 ° C. or higher.
As a result, there is a problem that the contact portion between the SiC pin 116 and the NiCr heat-resistant alloy support piece 115 is welded by a solid phase reaction, and this welding may cause breakage. Also, even if welding occurs, there is no problem during normal production, but if the ceiling 109 is shaken by vibration such as an earthquake and the welded part is forcibly peeled off, it will lead to fracture near the welded part from peeling of the welded part There was a fear.
For example, when a large force is generated due to an earthquake or the like, when the hook member 117 supported by the pin 116 is swung as shown by an arrow as shown in FIG. 10, a large force acts on the welded portion. As a result, cracks are generated in the welded portion, and at the same time, the crack propagates to the pin, which may break the pin itself or the portion fixed to the pin.

Further, since SiC is a material having excellent thermal conductivity, when the bottom side of the hook member 117 is heated to a temperature of 1000 ° C. or higher, it contacts the pin 116 and the pin 116 that are in contact with the hook member 117. The support piece 115 is also heated to a suitable temperature. However, since the NiCr alloy is inferior in high temperature creep characteristics as compared with ceramics, the support piece 115 made of NiCr alloy has a possibility of causing creep and extending.
Furthermore, according to the knowledge of the inventors of the present invention, since an oxide film is not formed on the surface in a reducing atmosphere containing hydrogen as in the float bath 101, SiC members are likely to be welded to each other. Estimated.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a hanger assembly that can withstand high heat when forming a high-temperature molten glass, hardly causes welding, and does not break. To do. Moreover, it aims at providing the manufacturing apparatus of the float glass plate provided with such a hanger assembly.

(1) A hanger assembly of the present invention is provided in a float bath apparatus including a float bath for a float glass glass manufacturing apparatus and a float bath roof installed above the float bath, and a ceiling portion of the float bath roof is provided. A hanger assembly for suspending a refractory brick constituting the hanger, wherein the hanger assembly locks a support rod member made of NiCr alloy, a hanger member made of SiC, the support rod member, and the hanger member. The connecting pin is formed of a sintered body made of Si ₃ N ₄ in which a plurality of Si ₃ N ₄ particles are bonded in a crystalline grain boundary layer.

(2) As for the hanger assembly of this invention, the friction coefficient with respect to the said hanger member of the said connection pin is the range of 0.2-0.5 in the inert gas atmosphere containing hydrogen, and 25 to 1000 degreeC.
(3) In the hanger assembly of the present invention, the friction coefficient of the connecting pin with respect to the support rod member is in the range of 0.1 to 0.5 in an inert gas atmosphere containing hydrogen and 25 ° C to 1000 ° C.

(4) The support rod member is formed in a direction in which the extending portion is extended to a rod-shaped extending portion, a branch portion formed on one end side of the extending portion, and an end portion of the branching portion. A plurality of support pieces having through holes for inserting pins; a connecting portion having a through hole for inserting the connecting pin is formed on one end side of the hanger member; and the firebrick on the other end side of the hanger member The structure in which the hook part which latches is formed is employable.
(5) A float plate glass manufacturing apparatus comprising: a float bath in which molten metal is housed; and a float bath roof having a ceiling portion formed by engaging a refractory brick with a hanger assembly; It is preferable that the hanger assembly is constituted by any one of the hanger assemblies described above.
(6) The float bath roof includes a ceiling portion that is installed on a side wall of the float bath, and a roof casing that is installed on the side wall of the float bath so as to cover the ceiling portion, and an upper portion of the roof casing. It is possible to adopt a configuration in which the support rod member of the hanger assembly is suspended through a steel material suspended from the hanger.

(7) The float plate glass can be applied to alkali-free glass having the following composition in terms of oxide-based mass percentage.
_{SiO 2: 50~73%, Al 2} O 3: 10.5~24%, B 2 O 3: 0~12%, MgO: 0~10%, CaO: 0~14.5%, SrO: 0~ 24%, BaO: 0~13.5%, MgO + CaO + SrO + BaO: 8~29.5%, ZrO 2: 0~5%.
(8) The float plate glass can be applied to alkali-free glass having the following composition in terms of oxide-based mass percentage.
_{SiO 2: 58~66%, Al 2} O 3: 15~22%, B 2 O 3: 5~12%, MgO: 0~8%, CaO: 0~9%, SrO: 3~12.5% BaO: 0-2%, MgO + CaO + SrO + BaO: 9-18%.
(9) The float plate glass can be applied to alkali-free glass having the following composition in terms of oxide-based mass percentage.
_{SiO 2: 54~73%, Al 2} O 3: 10.5~22.5%, B 2 O 3: 0~5.5%, MgO: 0~10%, CaO: 0~9%, SrO: 0 to 16%, BaO: 0 to 2.5%, MgO + CaO + SrO + BaO: 8 to 26%.

  According to the present invention, it is possible to provide a hanger assembly that is difficult to be welded and is not easily broken even when the ceiling portion provided in a float bath that molds molten glass at a high temperature is suspended and supported. Therefore, even if a high strain point glass such as non-alkali glass whose molding temperature is higher than that of general soda lime glass is molded, it is possible to provide a hanger assembly that does not weld and is not easily broken. It can be used to support the ceiling of the float bath.

The friction coefficient between the support rod member made of NiCr alloy and the connection pin made of the sintered body of Si ₃ N ₄ having a crystalline grain boundary layer is low, and the friction coefficient between the hanger member made of SiC and the connection pin is also low. The support rod member and the connecting pin are hardly fused, and the connecting pin and the hanger member are hardly fused. For this reason, since it is difficult for fusion to occur between the support rod member, the connecting pin, and the hanger member, the hanger assembly that suspends the ceiling portion of the float bath may be broken even if it receives vibration due to an earthquake or the like. Absent. This hanger assembly can stably support the ceiling of the float bath.

Sectional drawing which shows one Embodiment of the float bath provided with the hanger assembly which concerns on this invention. Sectional drawing which shows the dross box and slow cooling furnace which are provided and connected to the float bath. The side view of the hanger assembly. The hanger assembly is shown, FIG. 4 (A) is principal part sectional drawing, FIG.4 (B) is a side view of a support rod member, FIG.4 (C) is a front view of a support rod member. Side view illustrating an example of a test apparatus for measuring the friction coefficient of the Si ₃ N ₄ sintered body. Graph showing the results of measurement of the friction coefficient between the Si ₃ N ₄ sintered body and NiCr alloy. Graph showing the results of measurement of the friction coefficient between the Si ₃ N ₄ sintered body and SiC. Sectional drawing which shows an example of the suspension structure of the ceiling part in the conventional float bath. The cross-sectional schematic which shows an example of the hanger assembly which suspends and supports the ceiling part in the conventional float bath. Explanatory drawing which shows the state which a vibration acts on the hanger assembly and rock | fluctuates. Graph of intensity relationship common SiC and Si ₃ N ₄ sintered body.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of a hanger assembly according to the invention and an apparatus for producing a float sheet glass having the hanger assembly according to the invention will be described with reference to the accompanying drawings, but the invention is not limited to the embodiment described below. .
As shown in FIG. 1, the float bath apparatus 1 according to the present embodiment flows the molten glass G supplied to the float bath 2 along the surface of molten tin (molten metal) 3 accommodated in the float bath 2. It is an apparatus for forming a strip-like glass ribbon by spreading from both sides with a top roll (not shown) and flowing from the upstream side to the downstream side of the float bath 2.

  As shown in FIG. 1, the float bath apparatus 1 includes a float bath 2, an extension wall 2 c provided above the float bath 2, an upper side wall 2 d, a roof casing 5, and a ceiling portion 18. A molten glass melting furnace is provided on the upstream side of the float bath apparatus 1, molten glass G is supplied from the melting furnace to the float bath 2, and the glass ribbon 6 formed in the float bath 2 is as shown in FIG. 2. Then, it is conveyed to a slow cooling furnace 8 through a chamber 7 provided on the downstream side of the float bath 2. The glass ribbon 6 is pulled up from the surface of the molten metal 3 by a lift-out roll 9 provided in the chamber 7, transported to the slow cooling furnace 8 by the layer provided in the slow cooling furnace 8, and gradually cooled.

2 is a longitudinal sectional view of the float bath 2, the chamber 7, and the slow cooling furnace 8 along the moving direction of the glass ribbon 6 (the length direction of the glass ribbon 6), whereas FIG. 6 is a cross-sectional view taken along a width direction of FIG. In FIG. 2, only the outline of the float bath roof 5 of the float bath apparatus 1 is shown.
As shown in FIG. 2, the glass ribbon 6 that has been transferred from the float bath 2 to the slow cooling furnace 8 and cooled is cleaned by a cleaning device and then cut into a predetermined size by a cutting device. can get.

In the float bath 2 of the present embodiment, the lip 13 provided at the terminal end of the supply passage 12 is the molten glass G sent from the melting furnace (not shown) through the supply passage 12 to the inlet portion 2a at the upstream end. It comes to be supplied through. A tween 14 for adjusting the flow of the molten glass G is installed in the supply passage 12 upstream of the lip 13. The supply passage 12 and the float bath 2 are each constructed by assembling a plurality of heat-resistant materials such as refractory bricks, but are simply shown in FIG.
As shown in FIG. 1, the float bath 2 is composed of a molten metal bath 2A filled with molten tin 3 and an upper structure 2B installed on the upper portion of the molten metal bath 2A. The atmosphere is blocked as much as possible, and the inside is maintained in a reducing atmosphere such as an inert gas atmosphere containing about 1.5 to 10% of hydrogen.
As shown in FIG. 1, an extension wall 2c made of a side wall shielding block is formed on the side wall 2b of the float bath 2, and an upper side wall 2d is formed on the extension wall 2c. In FIG. 2, the configuration of each wall is shown in a simplified manner.

A front wall 15 that also serves as a part of the extension wall 2 c is formed on the upstream end side of the float bath 2, an inlet portion 2 a is formed on the bottom side of the front wall 15, and an extension wall is formed on the downstream end side of the float bath 2. A rear end wall 17 also serving as a part of 2c is formed, and an outlet portion 2c of the glass ribbon 6 is formed near the liquid surface of the molten metal 3 below the rear end wall 17.
The float bath 2 includes a front wall 15, a rear end wall 17, an extension wall 2 c, an upper side wall 2 d, and a float bath roof 5 to constitute an upper structure 2 </ b> B. The float bath roof 5 is made of metal and is provided so as to cover the upper space from the periphery of the upper side wall 2d.
In the upper structure 2B, the ceiling portion 18 is suspended and supported so as to be positioned on the extension wall 2c inside the upper side wall 2d. The ceiling portion 18 is configured by arranging a plurality of roof bricks 18A having a rectangular parallelepiped shape. A hanger assembly 21 (described later) passes through the boundary of the corner portion of the plurality of roof bricks 18A arranged in parallel, and the ceiling portion 18 is suspended. It is supported. A plurality of heaters 20 are suspended through a plurality of through holes 18b formed so as to penetrate the roof brick 18A vertically.

As shown in FIG. 3, the hanger assembly 21 of the present embodiment is sequentially suspended below the cable body 22 made of steel wire suspended from the ceiling portion of the roof casing 5 and the cable body 22. The support rod member 23, the connecting pin 26, and the hanger member 27 are included.
The rope body 22 is made of, for example, a steel material such as JIS regulation SS440.
As shown in FIG. 3, the support rod member 23 has a belt-like extending portion 23a, and is used to lock the cable body 22 to one side surface of a plate-like connecting portion 23b formed at the upper end portion thereof. A locking pin 23c is formed. A ring portion 22a formed at the lower end portion of the cable body 22 is connected to the locking pin 23c.
As shown in FIG. 3, two plate-like support pieces 23e are formed at the lower end portion of the extending portion 23a of the support rod member 23 via a bifurcated branch portion 23d, and penetrated to the distal end side of the support piece 23e. A hole 23f is formed.

  The support rod member 23 having the above-described structure is made of a NiCr-based Ni-base heat-resistant cast alloy, for example, a Ni-base heat-resistant cast alloy containing Cr and Fe called HW alloys as main additive elements. The HW alloy is a Ni-based heat-resistant casting alloy having about 55 to 65 mass% of Ni, adding about 14 to 18 mass% of Cr, and adding about 15 to 25 mass% of Fe. In addition to these additive elements, the HW alloy may contain about 1.0 to 2.0 mass% of Si and about 0.5 to 1.5 mass% of Mn.

A hanger member 27 is suspended below the support rod member 23 via a cylindrical connecting pin 26.
Connecting pin 26 is made of a crystalline sintered body of Si submicron grain boundary layer ₃ N ₄ Si ₃ N ₄ the particles in a plurality of binding as an example. Since Si ₃ N ₄ particles cannot be sintered alone, a sintering aid is necessary. In this embodiment, Y ₂ O ₃ is included, and particles that become crystalline after sintering with addition of ZrO ₂ as necessary. A boundary layer is preferred. These sintering aids are preferably contained in an amount of about 1 to 10% by mass with respect to the Si ₃ N ₄ particles.

  The hanger member 27 includes a plate-like connecting portion 28 having a through-hole 28a through which the connecting pin 26 is inserted, and a support piece 29 formed in a flared shape so as to extend the connecting portion 28 to the lower end side of the connecting portion. The lower end portion of the support piece 29 is composed of a T-shaped hook portion 30 extending at a right angle to the support piece 29.

As shown in FIG. 1, the hanger assembly 21 configured as described above suspends the rope body 22 from the ceiling portion of the roof casing 5, and the roof bricks 18A constituting the ceiling portion 18 as shown in FIG. The support rod member 23 and the support piece 29 are sandwiched between the butted portions, and the hook portion 30 is installed along the lower surface side of the roof brick 18A.
As described above, the structure in which the plurality of roof bricks 18A are supported by the plurality of hanger assemblies 21 is employed in the float bath apparatus 1 of the present embodiment.

  In the float bath apparatus 1, although depending on the scale, the ceiling portion 18 is supported by several thousand hanger assemblies 21 in a large apparatus. Of the several thousand hanger assemblies 21, all may have the above-described structure, but the temperature of the molten glass G is high on the upstream side of the float bath 2, and gradually decreases toward the downstream side. 6 and discharged from the outlet 2c of the float bath 2. For this reason, it is preferable that the hanger assembly installed in the area | region of the upstream of the float bath 2 exposed to especially high temperature is comprised with the hanger assembly 21 of this embodiment. In that case, the hanger assembly in the region excluding the upstream side may be a hanger assembly including a connection pin made of SiC. Further, both end sides in the width direction of the float bath 2 are regions where the molten glass G does not exist, and the temperature is lower than the center side in the width direction where the molten glass G exists, so a hanger assembly provided with a connecting pin made of SiC It may be.

  For example, in the case of a structure in which the ceiling 18 is suspended and supported by 2000 hanger assemblies, about 200 to 600 on the upstream side are used as the hanger assemblies 21 of the present embodiment, and the other hanger assemblies are A structure provided with a connecting pin made of SiC may be used. The other structure provided with the SiC connecting pin as the hanger assembly may have the same structure as the hanger assembly 21 shown in FIG. As an example, a hanger assembly using a connection pin made of SiC can be used in a temperature range of 950 to 1100 ° C., but in consideration of such aspects as welding, the hanger assembly is applied to a region of 1050 ° C. or higher. It is preferable to apply such a hanger assembly 21.

  An air supply pipe 29 is provided in the ceiling portion of the roof casing 5, and a reducing mixed gas composed of about 1.5 to 10% hydrogen and the remaining nitrogen gas is supplied from the air supply pipe 29 to the inside of the float bath 2. The space is always maintained in a reducing atmosphere above atmospheric pressure. The gas constituting the reducing atmosphere inside the float bath 2 slightly flows out to the chamber 7 side from the outlet 2c from which the glass ribbon 6 is drawn.

The chamber 7 provided on the downstream side of the float bath 2 includes a dross box 7A, a ceiling portion 7B, and a side wall (not shown). In this embodiment, three lift-out rolls 9 are provided inside the dross box 7A. Yes. The dross box 7A constitutes the bottom side of the chamber 7 so as to connect the float bath 2 and the slow cooling furnace 8.
In the dross box 7A, on the lower side of the lift-out roll 9, a wall-shaped pedestal 31 provided with a graphite seal block 35 on the upper side is arranged in order to block the air flow between the float bath 2 and the slow cooling furnace 8. Has been.

The ceiling portion 7 </ b> B of the chamber 7 includes a hood 32 installed between the float bath 2 and the slow cooling furnace 8, and a drape 33 suspended from the lower surface of the hood 32. The drape 33 is a plate-shaped partition member, and partitions the internal space of the chamber 7 into a plurality of space portions along the conveyance direction of the glass ribbon 6.
The slow cooling furnace 8 is configured as a passage type with a metal furnace shell 8A, and a plurality of layer rolls 9 are horizontally installed therein, and the glass ribbon 6 that has moved through the chamber 7 is conveyed by the plurality of layer rolls 10. It can be gradually cooled.

The float glass manufacturing apparatus 1 described above has a reducing atmosphere in which the upper space of the molten metal 3 is filled with an inert gas containing hydrogen gas in the float bath 2, and then from the inlet 2 a at the upstream end of the float bath 2. The glass ribbon 6 is formed while flowing the molten glass G toward the outlet 2c side at the downstream end. Then, the glass ribbon 6 is pulled up from the molten metal 3 by the lift-out roll 9 and transported to the chamber 7 side, and subsequently cooled by transporting it to the slow cooling furnace 8 side by the layer roll 10 to obtain the cooled glass ribbon 6. .
Moreover, the glass ribbon 6 is wash | cleaned with the washing | cleaning apparatus not shown provided in the downstream of the slow cooling furnace 8, and plate glass of the target width and length can be obtained by further cutting | disconnecting a glass ribbon with a cutting device in the downstream. .

As the glass applied to the molding of the glass ribbon 6 described above, alkali-free glass shown in the following composition examples can be applied.
As a first example, an alkali-free glass having the following composition in terms of oxide-based mass percentage can be used.
_{SiO 2: 50~73%, Al 2} O 3: 10.5~24%, B 2 O 3: 0~12%, MgO: 0~10%, CaO: 0~14.5%, SrO: 0~ 24%, BaO: 0~13.5%, MgO + CaO + SrO + BaO: 8~29.5%, ZrO 2: 0~5%.

As a second example, an alkali-free glass having the following composition in terms of oxide-based mass percentage can be used.
_{SiO 2: 58~66%, Al 2} O 3: 15~22%, B 2 O 3: 5~12%, MgO: 0~8%, CaO: 0~9%, SrO: 3~12.5% BaO: 0-2%, MgO + CaO + SrO + BaO: 9-18%.

As a third example, an alkali-free glass having the following composition in terms of oxide-based mass percentage can be used.
_{SiO 2: 54~73%, Al 2} O 3: 10.5~22.5%, B 2 O 3: 0~5.5%, MgO: 0~10%, CaO: 0~9%, SrO: 0 to 16%, BaO: 0 to 2.5%, MgO + CaO + SrO + BaO: 8 to 26%.
Examples of the plate glass produced by the float process using these alkali-free glasses include plate glass having a thickness of 0.7 mm to 0.1 mm, a vertical width of 2500 mm, a horizontal width of 2200 mm, and the like.

  When the production of the glass ribbon 6 is started as described above, even if the glass is a general soda lime glass, the soda lime glass is close to 1000 ° C. Molded at a temperature about 100 ° C. higher than lime glass. Therefore, the hanger member 27 of the hanger assembly 21 supporting the ceiling portion 18 is exposed to a higher temperature than ever. Further, the connection pin 26 is also heated to an appropriate temperature by heat conduction from the hanger member 27, and the lower side of the support rod member 23 is also exposed to a considerably high temperature.

When this temperature application is applied for a long time, welding occurs in the combination of the SiC hanger member having the conventional structure and the SiC connecting pin. Also, Ni-based heat-resistant alloys such as NiCr also weld to the SiC connecting pins.
In this respect, the combination of the SiC hanger member 27 and the connecting pin 26 of the Si ₃ N ₄ sintered body hardly causes welding. In addition, the support piece 23e made of a Ni-based heat-resistant alloy such as NiCr is less likely to be welded to the connecting pin 26 of the Si ₃ N ₄ sintered body. The reason why welding is difficult to occur in these combinations is that the coefficient of friction is small.
The combination of the SiC hanger member 27 and the connection pin 26 of the Si ₃ N ₄ sintered body makes it difficult for welding to occur, so even if vibration such as an earthquake is applied, the hanger member 27 and the connection pin 26 The hanger member 27 and the connecting pin 26 are not broken. Similarly, since the support piece 23e is less likely to be welded to the connection pin 26, the connection pin 26 and the support piece 23e are unlikely to break even when vibration such as an earthquake is applied.

In the structure of the present embodiment, the friction coefficient of the Si ₃ N ₄ connecting pin 26 against the NiCr alloy support rod member 23 is 0.2 to 0.5 at 25 ° C. to 1000 ° C. in an inert gas atmosphere containing hydrogen. The range of 0.12-0.45 can be employ | adopted more preferably.
In the structure of the present embodiment, the friction coefficient of the Si ₃ N ₄ connecting pin 26 against the SiC hanger member 27 ranges from 0.2 to 0.5 at 25 ° C. to 1000 ° C. in an inert gas atmosphere containing hydrogen. More preferably, a range of 0.3 to 0.4 can be employed.
If the friction coefficient is within the above range, not only when forming soda lime glass having a general composition, but also when forming alkali-free glass having the above composition with a high forming temperature, Si ₃ N _No welding of the _four connecting pins 26 to the SiC hanger member 27 occurs. Similarly, welding of the Si ₃ N ₄ connecting pin 26 to the NiCr alloy support rod member 23 does not occur.

A model test for measuring the relative friction coefficient of a support rod member made of NiCr alloy, a connecting pin made of a Si ₃ N ₄ sintered body, and a hanger member made of SiC was performed using the test apparatus having the configuration shown in FIG.
In the test apparatus shown in FIG. 5, a heater 51 is installed on a frame 50, and a plate-like fixed-side test piece 52 (50 × 50 × 10 mm) is installed on the heater 51. A thermocouple 53 for temperature measurement is installed at the end, and a cylindrical movable test piece 54 (φ20 × 15 mm) is arranged at the center of the upper surface of the fixed test piece 52. In addition, a holder 55 for supporting the movable side test piece 54 is provided on the movable side test piece 54, and is configured to be able to move simultaneously with the application of load from above the holder 55 vertically downward. Yes.
The friction coefficient was measured with the load applied to press the movable side test piece 54 against the fixed side test piece 52 as 10 kgf, the displacement speed 0.5 mm / min, and the relative displacement ˜0.5 mm.

As the movable side test piece, a test piece made of SiC and a test piece made of Si ₃ N ₄ were used. As a test piece made of SiC, CERALOY C manufactured by AGC Ceramics Co., Ltd., to which a sintering aid composed of Al ₂ O ₃ and Y ₂ O ₃ was added, was used.
As a test piece made of Si ₃ N ₄ , a sintered body (manufactured by Kurosaki Harima Co., Ltd.) having a crystalline binder formed by adding a sintering aid was used.
As the fixed-side test piece, a test piece made of NiCr alloy (heat-resistant cast alloy HW) and a test piece made of SiC were used.

There were two test temperatures: 25 ° C. and when the heater 51 was operated to heat the fixed-side test piece to 1000 ° C. The test atmosphere was performed in the air and in a nitrogen gas atmosphere containing 3% hydrogen.
Table 1 below and FIG. 6 show the test results of the movable side test piece made of SiC and the movable side test piece made of Si ₃ N ₄ on the fixed side test piece made of NiCr alloy.
Table 2 and FIG. 7 show the test results of the SiC movable side test piece and the Si ₃ N ₄ movable side test piece with respect to the SiC fixed side test piece.

From the test results shown in Tables 1 and 2 and FIGS. 6 and 7, the friction coefficient in the N ₂ + H ₂ mixed gas atmosphere is considerably high in the combination of the SiC test piece and the NiCr alloy fixed side test piece. On the other hand, it is apparent that the combination of the NiCr alloy stationary side test piece and the Si ₃ N ₄ movable side test piece is significantly lower. Therefore, by using a connecting pin made of Si ₃ N _4, it is possible to prevent sticking to a support rod member made of NiCr alloy. It can be seen that the pin is hardly broken and the support rod member is hardly broken.

From the test results shown in Table 1, the friction coefficient of the Si ₃ N ₄ connecting pin against the NiCr alloy support rod member is 0.2 to 0.5 at 25 ° C. to 1000 ° C. in an inert gas atmosphere containing hydrogen. A range can be employed, and more preferably, a range of 0.12 to 0.45 can be employed.
From the test results shown in Table 2, the friction coefficient of the Si ₃ N ₄ connecting pin against the SiC hanger member is in the range of 0.2 to 0.5 at 25 ° C. to 1000 ° C. in an inert gas atmosphere containing hydrogen. The range of 0.3-0.4 can be employ | adopted more preferably.

The cause of the above test results can be estimated as follows. The frictional resistance at the time of sliding is most affected by the combination of substances existing on the outermost surfaces of the opposing substances. In general, the surface of a material that is easily oxidized, such as NiCr, forms an oxide at a high temperature, and the friction coefficient decreases. However, the effect cannot be expected in a non-oxidizing atmosphere, and the friction coefficient increases due to a decrease in hardness. .
On the other hand, in the combination of nitrides, it is known that the friction coefficient of the combination of Si ₃ N ₄ and CN x becomes extremely low in vacuum. Although the mechanism for reducing the friction coefficient between nitrides is not necessarily clarified, in this test result, in an N ₂ —H ₂ atmosphere heated to 1000 ° C., an atomic level nitride layer is formed on the extreme surface of NiCr alloy or SiC. Is formed, and the sliding of the nitride with Si ₃ N ₄ is caused, so that it is considered that the friction coefficient is greatly reduced.

FIG. 11 shows the strength of Si ₃ N ₄ sintered body obtained by adding and sintering generally known Al ₂ O ₃ and Y ₂ O ₃ to Si ₃ N ₄ particles as sintering aids, The temperature dependence of the strength of the bonded body is shown. In the type of Si ₃ N ₄ sintered body using Al ₂ O ₃ and Y ₂ O ₃ as sintering aids, the grain boundary layer is composed of a glass phase.
As shown in FIG. 11, the Si ₃ N ₄ sintered body having the glass phase as the grain boundary layer starts to rapidly decrease in strength from above 600 ° C., and is higher than the SiC sintered body in the temperature range of 800 to 1200 ° C. The strength is significantly reduced. For this reason, it is difficult to apply a member made of a Si ₃ N ₄ sintered body in a region around 1000 ° C. or over 1000 ° C. such as when the molten glass G is formed.
On the other hand, in the embodiment of the present application, a Si ₃ N ₄ sintered body provided with a crystalline grain boundary layer is used, and a phenomenon of a low friction coefficient with respect to a hanger member made of SiC is used to make a NiCr alloy. The fact that it is possible to provide a hanger assembly that does not easily cause welding and is not easily broken by utilizing a phenomenon with a low coefficient of friction with respect to the support rod member has characteristics that cannot be obtained from a conventionally known technique.
From the comparison of strength shown in FIG. 11, it is difficult to adopt a Si ₃ N ₄ sintered body in place of the SiC sintered body in a high temperature range, but Si Si using a crystalline grain boundary layer as described above. By adopting the ₃ N ₄ sintered body, strength reduction at high temperature can be suppressed. Further, in an inert gas atmosphere containing 1.5 to 10% hydrogen as in the float bath 2, an oxide film that is normally generated at a high temperature is not generated on the surface of SiC, so that the problem of welding becomes apparent in SiC. . In view of this point, there is an advantage of using a Si ₃ N ₄ sintered body provided with a crystalline grain boundary layer.

  DESCRIPTION OF SYMBOLS 1 ... Float bath apparatus, 2 ... Float bath, 2a ... Inlet part, 2c ... Outlet part, 3 ... Molten metal, G ... Molten glass, 5 ... Roof chamber, 6 ... Glass ribbon, 7 ... Chamber, 8 ... Slow cooling furnace, 9 DESCRIPTION OF SYMBOLS ... Lift-out roll, 10 ... Layer roll, 18 ... Ceiling part, 18A ... Roof brick, 20 ... Heater, 21 ... Hanger assembly, 22 ... Rope body, 23 ... Support rod member, 23d ... Branch part, 23e ... Support piece , 23f ... through hole, 26 ... connecting pin, 27 ... hanger member, 28 ... connecting portion, 28a ... through hole, 29 ... support piece, 30 ... hook portion.

Claims (9)

A hanger assembly for hanging a refractory brick constituting a ceiling part of the float bath roof, provided in a float bath apparatus having a float bath for a float glass glass manufacturing apparatus and a float bath roof installed above the float bath Three-dimensional
The hanger assembly includes a support rod member made of NiCr alloy, a hanger member made of SiC, and a connecting pin that locks the support rod member and the hanger member.
A hanger assembly comprising a sintered body made of Si ₃ N _{4 in} which the connecting pin is a crystalline grain boundary layer and a plurality of Si ₃ N ₄ particles are bonded together.   The hanger assembly according to claim 1, wherein a friction coefficient of the connecting pin with respect to the hanger member is in a range of 0.2 to 0.5 in an inert gas atmosphere containing hydrogen at 25 ° C to 1000 ° C.   The hanger assembly according to claim 1 or 2, wherein a friction coefficient of the connecting pin with respect to the support rod member is in a range of 0.1 to 0.5 in an inert gas atmosphere containing hydrogen at 25 ° C to 1000 ° C. Solid. The support rod member is formed with a rod-shaped extending portion, a branch portion formed on one end side of the extending portion, and a direction in which the extending portion is extended to an end portion of the branch portion, and the connecting pin is inserted therethrough. A plurality of support pieces having through-holes,
The connection part provided with the through-hole which penetrates the said connection pin in the one end side of the said hanger member was formed, and the hook part which latches the said firebrick was formed in the other end side of the said hanger member. The hanger assembly as described in any one of these.   A float plate glass manufacturing apparatus comprising: a float bath in which molten metal is housed; and a float bath roof having a ceiling portion formed by engaging a refractory brick with a hanger assembly, the hanger assembly The manufacturing apparatus of the float plate glass in which the solid | solid was comprised with the hanger assembly as described in any one of Claims 1-4.   The float bath roof includes a ceiling portion that is constructed on a side wall of the float bath, and a roof casing that is installed on the side wall of the float bath so as to cover the ceiling portion, from above the roof casing. The apparatus for manufacturing a float glass sheet according to claim 5, wherein a support rod member of the hanger assembly is suspended through a suspended steel material. The apparatus for producing a float plate glass according to claim 5 or 6, wherein the float plate glass is made of an alkali-free glass having the following composition in terms of an oxide-based mass percentage.
_{SiO 2: 50~73%, Al 2} O 3: 10.5~24%, B 2 O 3: 0~12%, MgO: 0~10%, CaO: 0~14.5%, SrO: 0~ 24%, BaO: 0~13.5%, MgO + CaO + SrO + BaO: 8~29.5%, ZrO 2: 0~5%. The apparatus for producing a float plate glass according to claim 5 or 6, wherein the float plate glass is made of an alkali-free glass having the following composition in terms of an oxide-based mass percentage.
_{SiO 2: 58~66%, Al 2} O 3: 15~22%, B 2 O 3: 5~12%, MgO: 0~8%, CaO: 0~9%, SrO: 3~12.5% BaO: 0-2%, MgO + CaO + SrO + BaO: 9-18%. The apparatus for producing a float plate glass according to claim 5 or 6, wherein the float plate glass is made of an alkali-free glass having the following composition in terms of an oxide-based mass percentage.
_{SiO 2: 54~73%, Al 2} O 3: 10.5~22.5%, B 2 O 3: 0~5.5%, MgO: 0~10%, CaO: 0~9%, SrO: 0 to 16%, BaO: 0 to 2.5%, MgO + CaO + SrO + BaO: 8 to 26%.

Images