JP6576193B2 - Electrocast refractory tax tone and melting kiln - Google Patents

Description

  The present invention relates to a refractory, a method for producing the refractory, and a melting kiln using the refractory.

  The glass melting furnace has a lower structure that contains molten glass and is referred to as a melting tank, and an upper structure that is formed at the upper part of the lower structure and has a blow-out port that introduces a combustion flame such as natural gas into the kiln. Have. Since the upper structure has a large weight, a glass melting furnace is usually provided with a support structure for supporting the upper structure from the outside so that the load is not directly applied to the lower structure.

  Specifically, the support structure includes a support member that supports the refractory provided at the lower end of the upper structure in direct or indirect contact with the support member, and a structure that supports the support member from the outside. The refractory in contact with the support member is further provided so as to protrude to the inner side of the glass melting furnace so that a part of the refractory is also disposed above the lower structure. And by sealing the portion protruding to the inside and the lower structure, the temperature of the glass melting furnace is suppressed and the support member is protected from the high temperature atmosphere inside the glass melting furnace. (For example, refer to Patent Document 1 and Patent Document 2). This refractory is sometimes called a tax tone. In this specification, this refractory is referred to as a tax tone. For the tax tone, an electroformed refractory having a high compressive strength is mainly used so that the tax tone is installed on the support member and can sufficiently support the load of the superstructure.

  Furthermore, in the glass melting kiln, in order to suppress the release of heat to the outside and suppress the temperature drop inside the glass melting kiln, in the upper structure and the lower structure, a heat insulating brick is provided in a portion in contact with the external atmosphere. It is done.

JP 08-277119 A US Pat. No. 5,727,939

  However, it may be difficult to form a heat insulating material outside the furnace due to the shape or the like of the part where the tax tone and the support member are formed, and in that case, heat radiation at the place where the tax tone and the support member are provided. Therefore, extra energy is required to maintain the furnace temperature.

  Therefore, the present invention makes it easy to maintain the furnace temperature of the glass melting furnace and improve energy efficiency by improving the heat insulation of the tax tone without changing the arrangement of the components of the glass melting furnace. The purpose is to provide a simple tax tone.

  In addition, with respect to the said subject, improving heat dissipation is also considered by pinching | interposing a heat insulating material between a tax tone and a supporting member. However, in this case, since the large load of the superstructure is directly applied to the heat insulating material, the heat insulating material is likely to be crushed. Therefore, heat dissipation cannot be significantly improved by simply sandwiching the heat insulating material.

  The refractory according to the present invention is a glass melting furnace having a lower structure that accommodates molten glass, an upper structure formed on an upper portion of the lower structure, and a support member that supports the upper structure. It is a refractory disposed at the lower end, and is formed so as to protrude from the main body portion supporting the side wall of the upper structure to the inner side of the glass melting furnace than the main body portion, and to be disposed above the lower structure. A furnace inner portion, and having a recess in at least a part of the bottom surface of the main body portion.

  The method for producing a refractory according to the present invention is characterized in that the refractory material of the present invention is obtained by melting a refractory material, pouring the molten refractory material into a mold, cooling and solidifying.

  The glass melting furnace of the present invention has a lower structure that accommodates molten glass, an upper structure formed on an upper portion of the lower structure, and a support member that supports the upper structure, and is provided at a lower end of the upper structure. The refractory according to the present invention is provided.

  The refractory of the present invention is a refractory that can improve heat insulation while maintaining strength by being combined with a heat insulating material, and is suitable for use as a tax tone in a glass melting furnace.

  The method for producing a refractory according to the present invention can easily produce a refractory suitable for use as a tax tone.

  The glass melting furnace of the present invention makes it easier to maintain the temperature in the furnace of the glass melting furnace than before, and can improve energy efficiency. Thereby, manufacture of glass can be performed at low cost.

It is sectional drawing which shows schematic structure of the glass fusing kiln of this embodiment. It is an enlarged view of the tax tone of the glass melting furnace of FIG. It is explanatory drawing of the site | part of the tax tone of FIG. FIG. 3 is a left side view of the tax tone of FIG. 2. FIG. 3 is a rear view of the tax tone of FIG. 2. It is the figure which showed schematic structure of the refractory material which provided the heat insulating material in the recessed part of the tax tone of FIG. It is the figure which showed schematic structure of the refractory material which laminated | stacked two layers of heat insulating materials in the recessed part of the tax tone of FIG. It is the left view which showed schematic structure of the tax tone which is a modification of this embodiment. FIG. 7B is a rear view of the tax tone of FIG. 7A. FIG. 7B is a right side view of the tax tone of FIG. 7A. FIG. 7B is a diagram in which a plurality of tax tones of FIG. 7A are arranged side by side. It is a figure for demonstrating the magnitude | size of the tax tone of FIG. It is a figure for demonstrating the magnitude | size of the tax tone of FIG.

  The refractory, the refractory manufacturing method, and the glass melting furnace of the present invention will be described in detail below with reference to the drawings.

[Glass melting furnace]
First, the glass melting kiln in this embodiment is demonstrated. FIG. 1 is a cross-sectional view showing a schematic configuration of the glass melting furnace of the present embodiment.

  As shown in FIG. 1, the glass melting furnace 10 of this embodiment is the same as that of the past about the structure. That is, the glass melting furnace 10 includes a lower structure 11 that accommodates the molten glass 50, an upper structure 12 provided on the upper portion of the lower structure 11, and a support member 13 that supports the upper structure 12. The

  Here, the lower structure 11 includes a bottom portion 111 and a side wall 112 provided perpendicular to the bottom portion 111 so as to accommodate the molten glass 50. The lower structure 11 is a glass melting tank, and both are in direct contact with the molten glass 50. Therefore, the lower structure 11 is formed of a refractory excellent in heat resistance and corrosion resistance. As the refractory used here, electrocast refractories having good heat resistance and corrosion resistance are generally used, and specifically, alumina / zirconia / silica, zirconia electrocast refractories can be mentioned.

  The upper structure 12 is formed above the lower structure 11, and is formed with a side wall 121 continuing from the side wall 112 of the lower structure 11 and an upper structure (arch structure) on the upper side of the side wall 121 of the upper structure 12. And a ceiling 122. None of the upper structure 12 is in direct contact with the molten glass 50, but is in contact with the vapor of the molten glass 50, high-temperature combustion gas, or the like, so that it is also formed of a refractory having excellent heat resistance and corrosion resistance. . As the refractory used here, an electroformed refractory and a fired refractory excellent in heat resistance, corrosion resistance, and compressive strength are generally used. Specifically, for the side wall 121, generally, electrocast refractories such as alumina / zirconia / silica, alumina, zirconia, and fired refractories such as zircon, alumina / zirconia / silica, Examples of the ceiling 122 include siliceous fired refractories, alumina / zirconia / silica, and electrocast refractories such as alumina. A fired refractory is a refractory made by solidifying a raw material powder and firing it in a kiln. Sometimes called sintered refractory or bonded refractory.

  Moreover, the lower end of this upper structure 12 has a characteristic structure so that the fall of the internal temperature of the glass melting furnace 10 can be suppressed, supporting the upper structure 12 stably. In addition, this structure itself is also adopted in a conventional glass melting furnace, and is not a feature in the present embodiment. This structure will be described below. FIG. 2 is a partially enlarged view of the glass melting furnace 10 of FIG. 1 and is a view for explaining a connection portion between the lower structure 11 and the upper structure 12.

  In FIG. 2, the side wall 112 of the lower structure 11 has shown the example comprised by the firebrick 112a inside a furnace, and the heat insulation brick 112b outside a furnace. Moreover, the side wall 121 of the upper structure 12 has shown the example comprised by the firebrick 121a inside a furnace, and the heat insulation brick 121b outside a furnace. These refractory bricks and heat insulating bricks are both configured to exhibit predetermined characteristics by stacking bricks formed in a rectangular parallelepiped shape and arranging them in parallel. As a refractory brick and a heat insulation brick used here, the well-known firebrick and heat insulation brick applicable to a glass melting kiln can be used.

  A tax tone 123 is provided at the lower end of the upper structure 12. The tax tone 123 is disposed on a support member 13 to be described later, and is disposed on the lower structure 11. That is, the tax tone 123 is disposed on the lower structure 11 so as to suppress a temperature drop in the glass melting furnace 10 and is disposed on the support member 13 that supports the upper structure 12. Unlike other refractories, it has a characteristic shape so that no load is applied to the lower structure 11 as it is.

The space between the tax tone 123 and the lower structure 11 is preferably filled with a fixed refractory such as a fired refractory, an irregular refractory such as mortar, and a heat insulating material such as ceramic fiber. By filling with a refractory, there is no gap between the tax tone 123 and the lower structure 11, and heat dissipation can be suppressed.
The tax tone 123 is preferably provided in contact with the support member 13. By being provided in contact with the support member 13, the effect of suppressing the temperature drop in the glass melting furnace 10 is enhanced.

  The support member 13 is a member for supporting the load of the upper structure 12. The support member 13 is a part of the support structure of the upper structure 12 (the support structure other than the support member 13 is not shown). The support member 13 is preferably provided in contact with the upper structure 12 (specifically, the tax tone 123 provided at the lower end of the upper structure 12) as described above.

  The support member 13 is generally a metal support member formed in a flat plate shape. Moreover, the support member 13 should just be able to support the upper structure 12 stably, and can use the well-known support member which has predetermined intensity | strength and heat resistance.

  As the support member 13, a general structural rolled steel (JIS G3101) is generally used, and the allowable tensile stress is preferably 330 MPa or more. When the tensile strength is 330 MPa or more, the usage amount of the support member can be reduced. The tensile strength is more preferably 400 MPa or more.

The support member 13 preferably has a heat resistant temperature of 350 ° C. or higher. Here, the heat resistant temperature is a temperature that satisfies the allowable tensile stress specified in “Structure of pressure vessel—general matters” (JIS B8265), and the support member 13 has an allowable tensile strength at 350 ° C. of 82 MPa or more. It is desirable.
Examples of such support members include those formed of SS330, SS400, and the like.

[Tax tone]
Next, the tax tone characteristic in the present embodiment will be described. As described above, the tax tone 123 is disposed and used at the lower end of the upper structure 12, and is provided so as to be disposed also on the lower structure 11. The tax tone 123 is preferably provided so as to be in direct contact with the support member 13 that supports the upper structure 12.

  As shown in FIG. 3, the tax tone 123 supports the side wall of the upper structure 12, and is formed so that the main body part to which the load is directly applied and protrudes to the inner side of the glass melting furnace than the main body part. A furnace inner portion. That is, the main body portion refers to a region existing vertically below the side wall 121 (121a, 121b) forming the upper structure 12, and the load of the upper structure 12 sandwiched between the side wall 121 and the support member 13 is directly applied. Area. Here, the furnace inner portion is formed so as to protrude to the inner side of the glass melting furnace than the main body portion. Furthermore, the furnace inner portion may be formed so as to protrude downward. This structure contacts the lower structure 11 below the support member 13 and the main body part having a lower end surface formed flat so that the contact with the support member 13 can be stably performed on the surface. 13 and the lower structure 11 can be arranged as independent members without being influenced by each other.

  The most characteristic shape of the tax tone 123 used in the present embodiment is that the main body portion has a recess in at least a part of the contact surface with the support member 13. For example, as shown in FIGS. 4A and 4B, the surface of the contact surface with the support member 13 is different from the conventional tax tone in that a recess 123 a is formed in a part thereof. 4A shows a left side view of the tax tone 123, and FIG. 4B shows a rear view thereof. In addition, the figure which looked at the tax tone from the inner side of the glass fusing furnace 10 of sectional drawing shown in FIG. 1 was made into the front view. 7A to 7C are similarly represented.

  In FIG. 4A, since the concave portion 123a cannot be recognized from the outside, it is transparently indicated by a broken line. Moreover, in FIG. 4B, the boundary part with the supporting member 13 which tied the surface (bottom surface of a main-body part) arrange | positioned on the supporting member 13 as the recessed part 123a is also shown with the broken line. That is, the recessed part 123a formed in the main body part is a part recessed with respect to the broken line indicating the boundary part (a broken line and a part surrounded by a broken line above the broken line). Moreover, in FIG. 4B, the recessed part 123a is formed also in the furnace inner side part connected from the main-body part. Since the concave portion 123a of the furnace inner portion is formed downward from the boundary portion, the concave portion 123a has a broken line portion (a solid line indicating the outline of the tax tone) shown below the broken line indicating the boundary portion. It is shown as a part surrounded by (overlapping).

  As the tax tone 123, for example, an electroformed refractory is used. Electroformed refractories are obtained by completely melting the raw materials and then solidifying in the mold. The obtained refractories are filled with crystallized crystals and the matrix glass phase fills the intergranular and grain boundaries. Since it has such a fine structure and has a low porosity and a dense structure, it is excellent in terms of high heat resistance, high corrosion resistance, wear resistance, and the like.

As this tax tone 123, since the inside of the glass melting furnace 10 generally has a high temperature of 1300 ° C. or higher, it has a heat resistance equal to or higher than the internal temperature, and is a place where most of the load of the upper structure 12 is applied. High compressive strength is also required. The heat resistant temperature of the tax tone 123 is preferably 1500 ° C. or higher, more preferably 1600 ° C. or higher, and particularly preferably 1700 ° C. or higher. Here, the heat resistant temperature of the refractory is the load softening temperature T ₂ (° C.) defined by JIS R2209. Further, the compressive strength at normal temperature is preferably 100 MPa or more, more preferably 200 MPa or more, and particularly preferably 300 MPa or more.

The tax tone 123 is desirably composed of a dense structure having excellent corrosion resistance and strength and having few internal pores, and its bulk specific gravity is preferably 2.5 to 6.5. Here, the bulk specific gravity is a value obtained by dividing the measured weight by the volume obtained by measuring the outer dimensions. The bulk specific gravity is more preferably 3.0 to 6.5.
The true specific gravity of the tax tone 123 is preferably 3.0 to 6.5 because it is composed of a composition excellent in heat resistance, corrosion resistance, and strength. Here, the true specific gravity is a value calculated from the specific gravity of each composition and the composition ratio. The true specific gravity is more preferably 3.0 to 5.5.

  As this electrocast refractory, any known electrocast refractory can be used. For example, alumina / silica, alumina, alumina / zirconia / silica, zirconia, magnesia / chromium, chromium / alumina Quality, alumina, zirconia, silica, chrome, and the like. Of these, alumina, zirconia, and silica are preferred because they have good corrosion resistance to alkali. More specifically, examples of the electrocast refractory include ZB-1681 (trade name, manufactured by AGC Ceramics Co., Ltd.).

  Further, as shown in FIG. 5, it is preferable that the concave portion 123 a of the tax tone 123 is provided with a heat insulating material 124 to improve the heat insulating performance. As a heat insulating material used here, a well-known heat insulating material can be used without limitation as long as it has sufficient heat resistance to be used for a tax tone. In addition, as heat resistance, what has heat resistance more than the temperature of the tax tone at the time of use is sufficient, and what can endure the heat | fever above internal temperature of the glass melting furnace 10, for example, 1300 degreeC or more is preferable. In order to exhibit good heat insulation performance, the heat conductivity at 1000 ° C. of the heat insulating material is preferably 2.0 [W / m · K] or less, and 1.0 [W / m · K] or less. More preferred is 0.6 [W / m · K] or less.

  In addition, as a heat insulating material used here, a heat insulation castable is preferable. By using the heat insulating castable, the heat insulating material can be integrated with the tax tone 123 without generating an unnecessary gap in accordance with the shape of the concave portion 123 a of the tax tone 123. By integrating, the handling property at the time of construction of the glass melting kiln can be improved, and a tax tone with good heat insulation that can effectively suppress the heat radiation inside the glass melting kiln can be obtained.

  Moreover, as a heat insulating material, two or more types of heat insulating materials having different heat insulating performances can be used. When two types of heat insulating materials are used, the first heat insulating material 124a and the second heat insulating material 124b may be laminated as shown in FIG. Since the heat radiation from the furnace is suppressed by the first heat insulating material 124a, the second heat insulating material 124b can be used even with a heat insulating material having a heat resistance lower than that of the first heat insulating material 124a. In general, the heat insulating material has a low heat insulating property when the heat resistant temperature is increased, that is, the heat conductivity is increased. However, the second heat insulating material 124b has a high heat insulating material, that is, a material having a low heat conductivity. Can be used.

The thermal conductivity of the first heat insulating material 124a at 1000 ° C. is preferably 0.2 to 2.0 [W / m · K]. The thermal conductivity at 1000 ° C. of the second heat insulating material 124b is preferably 0.02 to 0.5 [W / m · K].
The ratio A / B of the thermal conductivity A at 1000 ° C. of the first heat insulating material 124a and the thermal conductivity B at 1000 ° C. of the second heat insulating material 124b is preferably 4 to 100. If A / B is 20 to 100, it is easy to suppress heat dissipation from the furnace.
The heat resistant temperature of the first heat insulating material 124a is preferably 1300 ° C. or higher, and more preferably 1400 ° C. or higher. The heat resistance temperature of the second heat insulating material 124b is preferably 800 ° C. or higher, and more preferably 900 ° C. or higher.

  With such a two-layer configuration, the heat reduced by the first heat insulating material 124a can be effectively insulated by the second heat insulating material 124b, and the heat radiation to the outside of the glass melting furnace 10 can be suppressed. Moreover, by setting it as such a 2 layer structure, the heat insulation performance as a total heat insulating material can be improved with the combination.

  As the heat insulating material that can be used here, any of an amorphous refractory such as a heat insulating castable, a ceramic fiber, a heat insulating board, a heat insulating brick, or the like can be used. In addition, as this heat insulating material, a heat insulating castable is preferable. This is because the heat-insulating castable is filled by pouring, so that the recess 123a of the tax tone 123 can be filled without any gaps, and the heat resistance is kept relatively good while having high heat insulation.

  Here, the heat-insulating castable is a refractory material in which a refractory aggregate is mixed with hydraulic cement or a chemical binder, and is an amorphous refractory material that can be molded by pouring water and pouring. Here, in order to improve heat insulation, it can achieve by using a hollow aggregate as a fireproof aggregate. Examples of the refractory aggregate include alumina, zirconia, alumina / zirconia, and alumina / zirconia / silica. Of these, alumina / zirconia is preferable in terms of heat resistance.

  More specifically, examples of the heat insulating castable that can be used here include TMT-1600 (trade name, manufactured by AGC Ceramics Co., Ltd.).

  The ceramic fiber is manufactured by using silica or alumina as a raw material, melting the raw material, or dissolving the raw material and the polymer, and fiberizing the obtained liquid. Ceramic fibers are also commercialized in various molded products such as felts, blocks, and boards described later. Examples of the ceramic fiber include 1600 bulk (trade name, manufactured by Isolite Kogyo Co., Ltd.).

The heat insulating board refers to a refractory heat insulating material made of ceramic fiber, inorganic particles, or the like formed into a board shape by using an inorganic binder or coating with heat resistant fibers.
Examples of the heat insulation board include TMT-MP (manufactured by AGC Ceramics Co., Ltd., trade name).

The heat insulating brick is a refractory brick provided with a large number of small bubbles in the refractory, and is generally produced by firing raw material powder in the same manner as the fired refractory.
Examples of the heat insulating brick include A-7 (trade name, manufactured by Isolite Kogyo Co., Ltd.).

  In addition, the fixed refractories such as heat insulation boards and heat insulation bricks require processing of the shape and the use of heat-resistant adhesive in order to fill the recess 123a without gaps, and the cost increases because it requires more labor than the irregular refractories. Tend to increase.

  In the case of a two-layer structure, the above heat insulating materials can be used in appropriate combination, but a heat insulating castable having a high heat resistance temperature that can withstand the furnace temperature is used as the first heat insulating material 124a, and the second heat insulating material is used. As 124b, it is preferable to use a heat-insulating board or the like that has better heat insulation and lower thermal conductivity than the first heat-insulating material 124a. The thickness of the first heat insulating material 124a is designed so that the temperature of the second heat insulating material 124b does not exceed the heat resistance temperature of the second heat insulating material 124b. The thickness of the first heat insulating material 124a is preferably 30 mm or more, more preferably 40 mm or more, and further preferably 50 mm or more in order to protect the second heat insulating material 124b and enhance the heat insulating effect. preferable. On the other hand, the thickness of the first heat insulating material 124a is preferably 100 mm or less, more preferably 90 mm or less, considering the strength of the tax tone 123 and the temperature increase of the first heat insulating material 124a. More preferably, it is as follows.

  The thickness of the second heat insulating material 124b is preferably 10 mm or more, more preferably 20 mm or more, and further preferably 30 mm or more in order to enhance the heat insulating effect. On the other hand, the thickness of the second heat insulating material 124b is preferably 60 mm or less, more preferably 50 mm or less, and more preferably 40 mm or less in order to prevent exceeding the heat resistance temperature of the second heat insulating material 124b. Is more preferable.

  4A to 4B show an example of the tax tone of the present embodiment, and a tax tone having a shape as shown in FIGS. 7A to 7C can also be used. 7A is a left side view of a tax tone which is a modification of the present embodiment, FIG. 7B is a rear view, and FIG. 7C is a right side view.

  The tax tone 223 shown in FIGS. 7A to 7C has a concave portion 223 a on the contact surface with the support member (the bottom surface of the main body portion), and the concave portion 223 a is provided wider than the concave portion 123 a of the tax tone 123. That is, the tax tone 123 is a both-leg type that makes contact with the support member 13 at both left and right ends (see FIG. 4B), whereas the tax tone 223 makes contact with the support member 13 only at the left end (see FIG. 7B). This is a single leg type performed at one end. In the recess 223a, a heat insulating material can be provided in the same manner as described above.

  Since the tax tone 223 has a contact surface with the support member 13 only on one side, the space of the recess 223a can be increased and the heat insulation can be further improved. In addition, since this one leg type cannot stand independently, it has the level | step difference which can adjoin the adjacent tax tone in the upper part of the side part in which the leg extended to a bottom face is formed. That is, in order to stabilize when a plurality of tax tones 223 are arranged, it has a protruding portion 223b supported by the adjacent tax tone and a notch 223c that becomes a step that can be engaged with the protruding portion 223b. .

  As shown in FIG. 8, when a plurality of the tax tones 223 are arranged, the protruding portion 223b and the notched portion 223c engage with the notched portion 223c and the protruding portion 223b of the adjacent tax tone 223, respectively. , Can be aligned stably. In addition, in FIG. 8, the example which provided the heat insulating material 124 in the recessed part 223a is shown.

Here, the size of the tax tone will be described with reference to FIGS. 9A and 9B. FIG. 9A shows a left side view of the tax tone 123, and FIG. 9B shows a rear view. The size of each part is shown with a reference numeral. Here, regarding the tax tone 123, it is assumed that the thickness is t _a , the height is h _a , and the width is w _a .

The thickness t _a tuck stone 123 is not particularly limited, it can be appropriately changed depending on the application and the like. The size is typically 300 to 700 mm as a tax tone of the glass melting kiln, and more preferably 450 to 600 mm in consideration of corrosion resistance and heat insulation properties and cost effectiveness. The thickness _{t a,} as shown in FIG. 9A, a thickness that the sum of _{t 1} and _{t 2} and _{t 3} and _{t 4.}

t ₁ is the thickness of the portion of the tax tone 123 that contacts the support member 13. That is, most of the upper structure 12 (the refractory bricks 121a, the heat insulating bricks 121b, and the ceiling 122 constituting the side walls stacked on the tax tone) is subjected to a load and can be supported sufficiently stably. Thickness. The t ₁ portion is formed flat according to the shape of the support member 13. Further, t ₁ is an important part in which the heat insulating material 124 is formed and affects the heat insulating performance.

Therefore, t ₁ may be set to a thickness that can sufficiently secure a contact area with the support member 13 and sufficiently secure heat insulation, and is preferably 100 to 600 mm, for example, and 225 to 420 mm. More preferred.

t ₂ is an intermediate portion that is connected from the flat portion to the furnace inner portion that becomes a joint portion with the lower structure 12. t ₂ is combined with _{t 1,} a thickness of the body portion. The _{t 2} may as long smoothly connecting the flat portion to the furnace interior portion, for example, preferably 0～150Mm, 25 to 150 mm is more preferable. Note that the t ₂ portion is a region where the heat insulating material 124 is formed in the same manner as t _1, and is also a portion that affects the heat insulating performance.

t _3, of the furnace interior portion of the tuck stone 123, refers to the recess 123a is formed continuously from the body portion portion, the thickness of the heat insulating material is formed. The t ₃ part, together with t ₁ and t ₂ , represents a region where the heat insulating material 124 is formed, and is also an important part that affects the heat insulating performance. This _{t 3} considers the balance of the heat insulating performance and corrosion resistance in a furnace interior portion, for example, when importance is attached to thermal insulation is preferably 20～250Mm, 50 to 300 mm is more preferable. For example, when emphasizing corrosion resistance, 0 to 150 mm is preferable, and 0 to 50 mm is more preferable.

t ₄ is the thickness of the electroforming furnace refractory inner portion of the tuck stone 123, the thickness of the furnace inner portion together with t _3. Since the inner part of the furnace touches the atmosphere in the furnace of the glass melting furnace 10 and is constantly eroded, the thickness of t ₄ is an important part that affects the corrosion resistance of the tax tone 123. That is, it is set to a thickness that can sufficiently withstand the erosion that the glass melting furnace 10 undergoes during the scheduled operation years, for example, 10 years of operation. Therefore, the thickness of the _{t 4,} the other shapes and production for glass tack Stone 123, but also affects the production temperature and the like, for example, when importance is attached to corrosion resistance, 100 to 350 mm is preferable, 175～3500Mm Is more preferable. For example, when importance is attached to heat insulation, 50 to 200 mm is preferable, and 50 to 100 mm is more preferable.

t ₃ the ratio _t 3 / _{t 4} of _{t 4} is preferably 0.0 to 2.5. In order to match the dimensions of the substructure, when increasing the t _3, it is preferable to reduce the t _4. Preferred _{that t} 3 / _{t 4} is 0.2 or more when importance is attached to thermal _{insulation, t} 3 / t ₄ is more preferably 0.1 or more. On the other hand, preferably _t 3 / _{t 4} is 0.1 or less when the emphasizing corrosion _resistance, t 3 / _{t 4} is more preferably 0.05.

Further, the total thickness of t ₁ and t ₂ (t ₁ + t ₂ ) is the thickness t _b of the main body portion, and the total thickness of t ₃ and t ₄ (t ₃ + t ₄ ) is the thickness of the inner portion of the furnace. When t _i is t _i , t _b is preferably 150 to 600 mm, and t _i is preferably 100 to 350 mm. The ratio between the thickness _{t i} of the thickness _{t b} and the furnace interior portion of the body portion _(t b / _{t i)} is preferably 1.0 to 6.0. When this ratio (t _b / t _i ) is small, the inner portion of the furnace is thick and the corrosion resistance is good. If this ratio (t _b / t _i ) is large, the area supported by the support member tends to be large and the stability tends to be good.

The height h _a tuck stone 123 is not particularly limited, can be appropriately changed depending on the application and the like. The size is typically about 200 to 400 mm as a tax tone of a glass melting furnace, and 300 to 350 mm is preferable in consideration of corrosion resistance, heat insulation and strength, and cost effectiveness.

h ₁ is a height obtained by removing the height t _{3 of the} concave portion from the height of the main body portion of the tax tone 123. That is, it is a portion to which most of the load of the upper structure 12 is applied and has a height (thickness) that can be supported sufficiently stably. The height of h ₁ is affected by the strength of the material used, but is preferably 60 to 280 mm, and more preferably 100 to 220 mm, for example.

h ₂ is the height of the portion protruding downward from the main body of the tax tone 123. That is, it is the height from the contact surface with the support member 13 to the lower end surface of the furnace inner portion formed for joining to the lower structure 11. This h ₂ is also a height for securing a space for inserting the support member 13, and the lower end surface of the inner portion of the furnace is surely in close contact with the lower structure 11 without being affected by the presence of the support member 13. It has a height that enables The height of h ₂ may be set according to the thickness of the support member 13 to be used, and is preferably 20 to 120 mm, and more preferably 40 to 90 mm, for example.

h ₃ is the height of the recess 123 a in the main body portion of the tax tone 123. That is, it is an important part which also becomes the height of the heat insulating material to be formed and greatly affects the heat insulating performance imparted to the tax tone 123. The thickness of the _{h 3,} also influenced by the thermal conductivity of the material used, etc., for example, preferably 30～130Mm, 50 to 100 mm is more preferable.

The width w _a of the tax tone 123 is not particularly limited, and can be changed as appropriate according to its use. The size is typically 200 to 700 mm as a tax tone of the glass melting furnace, and is preferably 300 to 550 mm in consideration of the volume of the heat insulating material 124 and the load applied to each tax tone 123. .

w ₁ and w ₂ are the widths of the legs that are the contact portions of the tax tone 123 with the support member 13. Each of w ₁ and w ₂ represents the width of the leg, and the width of the contact portion with the support member 13 is w ₁ + w ₂ . This is also a part to which most of the load of the upper structure 12 is applied, and is a width that can be supported sufficiently stably. The widths of w ₁ and w ₂ are influenced by the strength of the material used, but are preferably 15 to 100 mm, more preferably 40 to 100 mm, for example. Furthermore, it is preferable that the widths of w ₁ and w _{2 be} the same width in order to equalize the load.

w ₃ is the width of the recess 123 a of the tax tone 123. That is, it is an important part that also becomes the width of the heat insulating material to be formed and greatly affects the heat insulating performance imparted to the tax tone 123. The width of the _{w 3,} also influenced by the thermal conductivity of the material used, etc., for example, preferably 150~500mm, 270~670mm is more preferable.

The ratio w _a / w ₃ between w _a and w ₃ is preferably 1.05 to 2.3. Preferably _{the w} a / _{w 3} is equal to or more than 1.1 when importance is attached to load _{bearing, w} a / w ₃ 1.13 or more is more preferable. On the other hand, when importance is attached to heat insulation, w _a / w ₃ is preferably 1.5 or less, and w _a / w ₃ is more preferably 1.3 or less.

Moreover, it is preferable that the capacity | capacitance of the tax tone 123 is 2.0-20.0L. If the capacity | capacitance of a recessed part is 2.0L or more, sufficient heat insulating material can be provided and the heat radiation inside a glass melting furnace can be suppressed effectively. The volume of the recess is more preferably 5.0 L or more, and further preferably 7.0 L or more. On the other hand, if the capacity of the recess is 20 L or less, the thickness of t ₄ of the tax tone 123 shown in FIG. 9A can be increased to improve the corrosion resistance, and the thickness of h ₁ shown in FIG. 9B can be increased to improve the load resistance. it can. The capacity of the recess is more preferably 16.0 L or less, and further preferably 10.0 L or less.

The size of the tax tone is described for the case of the both-leg type, and in the case of the one-leg type, it can be appropriately changed according to the difference in shape. For example, in the width of the tax tone, the width of the leg serving as the contact portion with the support member 13 is one, so that the width is about 1.0 to 2.0 times that of w ₁ or w ₂ described above. It is preferable to set it to about 1.0 to 1.9 times. By doing in this way, while receiving the load of the upper structure 12 firmly, a recessed part can be formed larger than a both-leg type, As a result, the formation area of a heat insulating material can be expanded, Therefore The heat insulation performance of a tax tone is improved. Can do.

In addition, as shown in FIGS. 7A to 7C, the single leg type is characterized by having a protrusion 223b and a notch 223c. However, the protrusion width of the protrusion 223b and the notch 223c are not cut. As for notch width, as for all, about 20-60 mm is preferable. If it is 20 mm or more, it is easy to arrange stably as shown in FIG. If it is 60 mm or less, the width w _{3 of the} heat insulating material can be widened while suppressing the interference between the protruding portion 223 b and the notched portion 223 c due to expansion at the time of temperature rise. Moreover, as for the height of this protrusion part 223b and the height of the notch part 223c, all are about 80-200 mm. If it is 80 mm or more, it is easy to arrange stably as shown in FIG. If it is 200 mm or more, the notch 223c and the recess 223a approach excessively, the thickness of the tax tone 223 becomes thin, and the strength is insufficient.

  As described above, by adopting the configuration of the present embodiment, it is possible to obtain a tax tone that can improve heat insulation while maintaining a good load resistance. When this tax tone has a heat insulating material, an unnecessary load is not applied to the heat insulating material. Therefore, a material having a desired heat insulating performance can be selected without worrying about strength.

[Method for producing refractory]
The method for producing a refractory according to the present embodiment melts a refractory raw material prepared at a ratio of a predetermined refractory composition, and then pours the molten refractory raw material into a mold, cools and solidifies, and the above described taxone. Is to be manufactured. In this manufacturing method, the refractory may be manufactured by a known method. Hereinafter, each step will be described in detail.

  First, raw materials such as alumina, zirconia, silica, sodium carbonate and the like are mixed at a predetermined ratio so as to obtain a target refractory composition to prepare a refractory raw material. Next, the obtained refractory material is heated and melted in an electric furnace or the like. Here, 1700 degreeC or more is preferable and the heating temperature of the refractory raw material in an electric furnace has more preferable 1800-2100 degreeC. The electric furnace is preferably an arc electric furnace. As the electrode of the electric furnace, a graphite electrode can be used.

  Next, the molten refractory material is poured into a mold and gradually cooled to solidify. Here, the mold is formed so as to obtain a desired refractory shape. In refractory manufacturing, the surface of the resulting refractory ingot may be processed by cutting, polishing, etc. to obtain a product shape. It is formed larger than the size.

  Slow cooling refers to cooling the molten refractory to a temperature at which the refractory can be handled after pouring it into a mold. The temperature that can be handled is preferably 50 ° C. or lower. In order to reduce the incidence of cracks, the slow cooling time is preferably 7 days or longer, and more preferably 15 days or longer.

  In this embodiment, since the target refractory shape has a recess at a predetermined position, the recess may be formed as a mold. Alternatively, a conventional mold for producing a tax tone having no concave portion can be used as it is, and a core that can be removed later is disposed in a portion to become a concave portion, and can be manufactured by melt casting. In this case, it is possible to manufacture a tax tone having a concave portion of a predetermined shape by once forming the ingot and the core integrally and removing the core later.

  By forming a heat insulating material in the concave portion of the tax tone having the concave portion thus obtained, a tax tone with improved heat insulation can be obtained. Here, as the heat insulating material, the heat insulating material as described in the description of the tax tone can be used.

  In the above, the case where the heat insulating material is formed later after the formation of the recess has been described. However, if a heat insulating material that can be used as a product is arranged as it is instead of the core, a casting obtained by casting is obtained. A lump is obtained integrated with the insulation. In this case, it can be used as a tax tone with improved heat insulation performance as it is, and the steps of removing the core and forming the heat insulating material can be omitted. According to this manufacturing method, the taxtone manufacturing process is simplified, and the manufacturing cost can be reduced.

[Glass melting furnace]
The glass melting furnace of the present embodiment has a lower structure that accommodates molten glass, an upper structure that is formed in close contact with the upper portion of the lower structure, and a support member that supports the upper structure, and a lower end of the upper structure. Is provided with a tax tone. Here, the tax tone of the present embodiment described above is used as the tax tone. About another structure, what is necessary is just to be the structure in a well-known glass melting kiln. Examples of the glass melting kiln include the glass melting kiln illustrated in FIG.

  Examples of the present invention and comparative examples are shown below.

Example 1
Refractory raw materials such as alumina, zirconia, silica, and sodium carbonate were mixed at a predetermined ratio to obtain a refractory composition. This refractory composition was charged into a 3000 kVA single-phase AC arc electric furnace equipped with three graphite electrodes, and completely melted at a temperature of 1800 to 2000 ° C. by current heating. Next, as a core for forming a recess, a heat insulating castable having a predetermined shape is disposed at a predetermined position, and the molten metal is poured into a mold embedded in silica sand as a slow cooling agent, after casting The mold was removed from the mold and allowed to cool to near room temperature.

The heat insulating castable formed integrally with the ingot was removed by crushing, cutting and polishing to obtain a double leg type tax tone having a concave portion shown in FIG. The resulting size of the tuck stone, _{t a} is 491mm _{(t 1} is 316 mm, _{t 2} is 50 mm, _{t 3} is 25 mm, _{t 4} is 100 mm), _{h a} is 300 mm _{(h 1} is 162 mm, _{h 2} is 66mm H ₃ is 72 mm) and w _a is 450 mm (w ₁ is 55 mm, w ₂ is 55 mm, w ₃ is 340 mm). Moreover, the capacity | capacitance of the recessed part at this time is 10.0L.

  Further, the composition, true specific gravity, and compressive strength of the obtained tax tone are shown in Table 1. Here, the true specific gravity is a value calculated from the specific gravity of each composition and the composition ratio. The compressive strength is a value measured according to JIS R2206. This tax tone is an electroformed refractory equivalent to ZB-1681 (AGC Ceramics Co., Ltd., trade name).

Next, as the heat insulating material, a heat insulating castable (manufactured by AGC Ceramics Co., Ltd., trade name: TMT-1600) is used, and a wooden plate and a polystyrene foam plate are installed on the side surface of the recess, and the heat insulating castable kneaded with water is poured into the recess. Then, it was left to cure for about 1 day to form a heat insulating material 1 having a height of 57 mm (part of h ₃ ).

  Furthermore, the heat insulating material 2 formed into a plate shape having a thickness of 15 mm to be a contact surface with the support member by applying air-hard mortar (manufactured by AGC Ceramics Co., Ltd., trade name: TMA) to the surface of the cured heat-insulating castable. (AGC Ceramics Co., Ltd., trade name: TMT-MP10RHY; thermal conductivity (400 ° C.) 0.026 W / m · K) was pasted to obtain a tax tone having two layers of heat insulating material in the recesses. At this time, the heat insulating material in the furnace inner part was formed only by heat insulating castable.

The heat insulating material 1 used here is a heat insulating material formed using a heat insulating castable having the chemical composition shown in Table 2. Table 2 also shows the characteristics of the obtained heat insulating material. Here, the specific gravity is the bulk specific gravity, and was determined by measuring the weight of the heat insulating material and measuring the outer dimensions and dividing by the calculated volume. The maximum operating temperature was determined by the following method. First, a plurality of heat insulating materials were prepared. This heat insulating material was heated at a constant temperature for 3 hours so as to be heated at different temperatures in increments of 50 ° C., and it was observed whether the heat insulating material melted and the edge of the heat insulating material was deformed. At this time, the highest temperature at which the edge of the heat insulating material was not deformed was defined as the maximum use temperature.
Here, the thermal conductivity is a value measured by a hot wire method in accordance with JIS R2251-1.

  The heat insulating material 2 used here is a heat insulating board mainly composed of silica particles and coated and molded with glass cloth. Table 3 shows the characteristics of the heat insulating board. Here, the specific gravity is the bulk specific gravity, and was determined by measuring the weight of the heat insulating material and measuring the outer dimensions and dividing by the calculated volume. The thermal conductivity is a value measured by ISO 8320, ASTM C177 GHP method.

(Example 2)
The one-leg type tax tone shown in FIGS. 7A to 7C was manufactured in the same manner as in Example 1. 9A to 9B, the size of the obtained tax tone is 491 mm for t _a (291 mm for t ₁ , 50 mm for t ₂ , 25 mm for t ₃ , 125 mm for t ₄ ), and 300 mm for h _a (h ₁ is 162 mm, _{h 2} is 66 mm, _{h 3} is 72 mm), _{w a} is 450 mm _{(w 1} 60 mm, _{w 2} is 0 mm, is _{w 3} 390 mm), a. Further, in this one leg type tax tone, the protruding portion and the notch portion are provided with a width of 30 mm and a height of 100 mm, respectively. That is, the width including the protruding portion of the tax tone is 480 mm. Moreover, the capacity | capacitance of the recessed part at this time is 9.8L.

  Furthermore, the heat insulating material 1 and the heat insulating material 2 were laminated | stacked on the obtained tax tone similarly to Example 1, and the tax tone which has a two-layer heat insulating material in a recessed part was obtained.

(Insulation simulation)
Moreover, in order to estimate the heat insulation effect about the refractory of this invention, the computer simulation was implemented using the three-dimensional heat transfer calculation program by a finite volume method.
Here, as the tax tone used for the glass melting furnace, when using the tax tone having no concave portion of the conventional example, when using the tax tone having the concave portion of the present invention, the outside of each glass melting kiln The amount of heat released to was calculated and the difference was calculated. At this time, the conditions other than the tax tone were the same, and the temperature inside the glass melting furnace (furnace inner surface) was set to 1600 ° C.

In addition, as a material of this tax tone, an alumina / zirconia / silica electrocast refractory was assumed, and its thermal conductivity (30 ° C.) was set to 5.813 [W / m · K]. Further, the dimensions of the tax tone were as follows in FIGS. 9A and 9B.
Conventional refractories as (tuck stone), _{t a} is _{500mm, t} 1 + t ₂ is 375 mm, _{t 3} are 0 mm, _{t 4} is 150 mm, _{h a} is 305 mm, _{h 1} is 239 mm, _{h 2} is 66 mm, _{w a} Is 450 mm, and no heat insulating material is provided.
The refractory of the present invention (tack Stone), _{t a} is _{515mm, t} 1 + t ₂ is 375 mm, _{t 3} is 25 mm, _{t 4} is 125 mm, _{h a} is 305 mm, _{h 1} is 165mm, _{h 2} is 66 mm, h ₃ is 74 mm, w _a is 450 mm, w ₁ (w ₂ ) is 30 mm, w ₃ is 390 mm, and the recess has a height of 59 mm from the refractory (tax tone) side and a thermal conductivity (30 ° C.) of 0.480 [ A heat insulating castable of W / m · K] and a heat insulating board having a height of 15 mm and a thermal conductivity (30 ° C.) of 0.050 [W / m · K] were formed.

  As a result, when the tax tone of the present invention was used, the heat radiation amount of 2.8 kW / m per 1 m of the outer circumference of the kiln was reduced as compared with the conventional case. From this result, for example, when the tax tone of the present invention is used for the entire circumference 50 m of a 15 m × 10 m melting furnace, an energy saving effect of 140 kW is expected.

  As described above, the tax tone of the present embodiment can improve the heat insulating property by providing the concave portion while maintaining the characteristics of the refractory such as heat resistance and corrosion resistance. Actually, by providing a heat insulating material in the recess, it is possible to obtain a tax tone that has improved heat insulation and is suitable for use in a glass melting furnace.

  The taxtone of the present invention can be widely used as a refractory that requires heat resistance, corrosion resistance, heat insulation, and the like, and in particular, can be suitably used as a taxtone for a glass melting furnace.

  DESCRIPTION OF SYMBOLS 10 ... Glass melting furnace, 11 ... Lower structure, 12 ... Upper structure, 13 ... Supporting member, 111 ... Bottom part, 112, 121 ... Side wall, 121a ... Fire brick, 121a, 121b ... Thermal insulation brick, 122 ... Ceiling, 112a, 123 ... Tax tone, 124 ... Heat insulation

Claims (13)

In a glass melting furnace having a lower structure that accommodates molten glass, an upper structure formed on an upper portion of the lower structure, and a support member that supports the upper structure, electroforming disposed at a lower end of the upper structure Refractory tax tone ,
A main body part that supports the side wall of the upper structure, and a furnace inner part formed so as to protrude to the inner side of the glass melting furnace than the main body part and to be disposed above the lower structure,
Electrocast refractory steel tack stone, characterized by having a recess in at least part of the bottom surface of the body portion. The electrocast refractory tax tone according to claim 1, wherein the electrocast refractory is an electrocast refractory of alumina, alumina / zirconia / silica, or zirconia. Electrocast refractory steel tack stone according to claim 1 or 2 capacity of the recess is 2.0～20.0L. The thickness _{t i} of a furnace interior portion of the electrocast refractory steel tack stone 100 to 350 mm, the is the thickness _{t b} of the body portion of the electrocast refractory steel tack stone 150～600Mm, their ratio (t _b / _{t i)} is electroformed refractory steel tack stone according to any one of claims 1 to 3 1.0 to 6.0. The electroforming the recess in a part of refractory steel tack stone furnace interior portion of is formed continuously from the body portion, wherein the furnace is the thickness t ₃ of the recess in the inner part 0～300Mm, the furnace inner 5. The thickness t _{4 of the} portion other than the concave portion is 100 to 350 mm, and the ratio (t ₃ / t ₄ ) thereof is 0.0 to 2.5. 5. electroforming refractory made tack Stone. The electrocast refractory steel tack stone width _{w a} is 200 to 700 mm, the a electrocast refractory steel tack Stone recess width _{w 3} of the 150～500Mm, their ratio _(w a / _{w 3)} is 1 electrocast refractory steel tack stone according to any one of claims 1 to 5 is .05～2.3. Wherein when viewed body portion from the furnace outer electroforming refractory steel tack stone according to any one of claims 1 to 6, legs extending to the bottom surface is formed only on one side. In the body portion, the upper portion of the side legs extending to the bottom surface is formed, electroformed refractory steel tack stone according to claim 7, adjacent electrocast refractory steel tack stone has a step which can be engaged . Electrocast refractory steel tack stone according to any one of claims 1 to 8 are heat-insulating material is provided in a recess of the electrocast refractory steel tack stone. The insulation is electroformed refractory steel tack stone according to claim 9 in which two or more kinds of heat-insulating material of different heat insulating performance are laminated. The said heat insulating material is a heat insulation castable, The electrocast refractory tax tone of Claim 9 or 10. 12. The electroformed refractory tax tone according to claim 1, wherein a corner portion of the recess has an R shape. A substructure for containing molten glass;
An upper structure formed on top of the lower structure;
A support member for supporting the superstructure,
Wherein the lower end of the upper structure, the glass melting furnace, characterized in that a electrocast refractory steel tack stone according to any one of claims 1 to 12.

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