JPH07157316A - Method for promoting change of body for glass smelting furnace - Google Patents

Abstract

PURPOSE:To change bodies rapidly while maintaining high quality by making combination use of electric boosters and stirrers installed at the feeders with a glass smelting furnace for changing bodies having a smelting section, a working section and the feeders. CONSTITUTION:The glass smelting furnace 1 fuses the glass raw materials charged into the smelting section 2 by heating means, such as burners, and feeds fused glass successively from a throat 5 into the working section 3. The smelting section 2 of such furnace is provided with the plural electric boosters 6 and/or oxygen burner sets so as to attain a glass pulling up quantity (ton/ day)/fused glass holding quantity (ton)>1. All feeders 4 are provided with stirrers installed respectively with four pieces of stirrers in two rows. Local heating and glass convection are increased by the plural electric boosters 6 and the glass is forcibly stirred during the body change period by these stirrers. The generation of unequal colors, unequal compsn., etc., is prevented and the purposes are achieved by this method.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is for changing ground (composition, color).
In the glass melting furnace for industrial use, an electric booster and a stirrer are installed, and the purpose is to complete the material replacement in a short period while maintaining high quality.

[0002]

2. Description of the Related Art Conventionally, as a method for changing the base material (including composition change or color change) of molten glass in a glass melting kiln, the old glass from the bottom of the kiln called the Dreand-fill method (also called unbleaching method) The method of pulling out most of the material and moving to a new molding, and the new glass raw material is put into the melting part called the transition change method (also called extrusion method) and melted, the old molten glass base material is sequentially passed through the working part and the feeder. There has been a method of replacing the ground while draining it. The former was only performed occasionally at the time of extreme changes such as color change from black to white, and the latter was common. In the latter case, measures such as raising the temperature of each of the melting section, working section and feeder have been taken in order to promote the replacement of the molten glass base material. In addition, when a dyed glass product is produced in a glass melting furnace, the temperature of the bottom tends to drop, so that the structure is relatively shallower than the flint glass furnace (for example, around 1000 m / m) for the purpose of further maintaining the bottom temperature. It has been common practice to install electric boosters.

However, in such a conventional method of changing the substrate, homogenization is a natural convection of the glass in the kiln, and since the homogeneity cannot be controlled, the range of change is increased in order to speed up the substrate change. When it is increased, glass having different compositions are mixed with each other to cause a product defect called "composition unevenness" or "color unevenness". Further, in some cases, the replacement of the molten glass base material in the working section was delayed, and the residual glass base material gradually flowed out in the latter half of the replacement of the base material, causing the same "composition unevenness" or "color unevenness" as described above. Therefore, in changing the substrate, the target color tone (composition) is gradually changed within a range in which the product defects such as color unevenness and composition unevenness (code) do not occur. However, in this method, the above-mentioned drawbacks would occur unless the change was made slowly and step by step. Therefore, it took a very long time.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and is capable of completing the material replacement in a short period while maintaining high quality.

[0005]

According to the present invention, a glass melting furnace having a melting part, a working part and a feeder (glass pulling amount (ton / day) / ceramic glass holding amount (ton))> 1
(Here, the amount of kiln glass held is the total amount of molten glass in the melting section, working section and feeder.) So that all of the electric boosters and / or oxygen burner sets installed in the melting section The glass pulling amount and the homogeneity of the glass are forcibly improved by the stirring device provided in the feeder.

The process leading to the present invention will be described. It has been known that the period for replacing the material in the melting furnace is almost determined by how much molten glass is flown relative to the amount held in the kiln. Therefore, it was considered important to maximize the (maximum glass outflow rate (ton / day)) / (ceramic glass holding amount (ton)) in order to shorten it. This value is generally about 0.6 to 0.8, and it is usually not considered that it exceeds 1. In other words, if it is raised further, the kiln will be damaged and the life of the kiln will be shortened, or the quality of the kiln will be significantly deteriorated during the replacement of the material, and the cost of the electric booster will be unavoidably increased. However, in the present application, conversely, the technology was pursued on the premise that the value was made larger than 1. Here are some possible ways to do this: (1) Speed up (increasing the amount of glass pulled,
(Glass pulling amount (ton / day) / ceramic glass holding amount (ton)) is increased. ) Change the objective configuration (1) -Install an electric booster for color change. Conventionally, an electric booster is high in cost, and it is common to use a minimum to maintain the bottom temperature, but this is used to the maximum. (1)-Glass melting ability is increased by heating with an oxygen burner. (2) Change in composition for the purpose of preventing composition unevenness (color unevenness) (2) -Install a stirring device on all feeders. Even if the substrate replacement step is changed significantly, it is possible to prevent color unevenness and codes from appearing.

Therefore, the method (1) was repeatedly examined. The first electric booster was originally
This is a device that installs an electrode in glass that is melted in a melting furnace and applies an electric current to increase the melting capacity. The purpose of use is to increase the pulling amount because of its features such as high thermal efficiency for oil combustion, easy response to additional pulling fluctuations, and local heating for low temperature parts. ing. In the present application, the electrode material is not particularly limited, but molybdenum is preferable in many respects, and platinum, tin oxide, graphite, etc. may be used. In the present invention, it has been found that providing a plurality of electric boosters for the purpose of accelerating the replacement of the material produces a very high effect. Regarding the position of installation, it is desirable to insert the electrode from the bottom in terms of efficiency, but it may be from the side. Here, the electrode can be inserted by making a hole in the brick block and inserting from there, so that it can be installed even during operation and can be installed later. Also, the pulling amount can be increased by the method of increasing the melting capacity by the oxygen burner set.

Further, it has been found that if a stirring device is installed in all the feeders, it is very effective in accelerating the replacement of the substrate. As a means to improve homogeneity only by natural convection, at least two rows of stirrers or padlers are installed on all forehearths to control homogeneity (color unevenness, composition unevenness). As a result, deterioration of homogeneity, which is a disadvantage due to speedup, can be prevented. Furthermore, since the uniformity (color unevenness, composition unevenness) is maintained even if the change range is made large, it is expected that color change is promoted. However, (1),
Even if the method of (2) is used alone, each effect is obtained,
It has been found that the homogenization is insufficient because only (1) shortens the melting time of the glass for speeding up. On the other hand, with (2) alone, color unevenness is reduced, but speedup is small. With (1) + (2), the lack of homogenization in (1) is supplemented by (2), resulting in speedup and compositional unevenness (color unevenness). Both sides resolved. Further (1) +
Since the change range can be increased by (2), the time can be further shortened, and the synergistic effect of (1) + (2) is created. Then, the change magnification can be increased from the beginning until the change of the material replacement is replaced with the desired composition (or color), and as a result, the material replacement period can be shortened. For example, at the time of color change, the colorant was initially added in an amount less than twice the target color and changed in stages, but the colorant should be added four times the target color to accelerate the coloring. Is possible.

[0009]

EXAMPLES The present invention will be described in more detail with reference to examples. FIG. 1 shows an embodiment of the present invention.
Is a glass melting furnace, and the melting furnace 1 is composed of a melting section 2, a working section 3, and a feeder 4. The glass raw material charged into the melting part 2 is melted by a heating means (burner or the like) not shown, and the molten glass is successively fed into the working part 3 from the throat 5. Here, in the melting part 2, a plurality of electric boosters 6 are provided.
Are installed (at 20 places in the figure), and local heating of the melting part 2 and increase of glass convection will be performed. Also,
Four stirrers are installed in each of the feeders 4 in two rows, and they are forcibly agitated during the material replacement period. Then, it is supplied to the glass product molding machine according to a usual method. in this way,
By using the electric booster 6 and the stirrer 7 together, the replacement of the glass base material is promoted throughout the glass melting furnace 1, and the composition unevenness and the color unevenness due to the residual glass base material are generated in a shorter time than the conventional method. Therefore, it is possible to reduce the time required for changing the substrate.

Examples of the present invention will be described below. (Example 1) In a glass melting furnace having a glass holding capacity of 235 tons, 20 electric boosters were prepared, and electrodes (both molybdenum electrodes) were inserted from the side faces in the arrangement shown in FIG. Heating was performed with electric power. At the same time, 4 in each of 3 feeders
Stirring was performed with a stirrer arranged in two rows. As a comparative example, the material was replaced with the same amount of glass melting furnace without using the electric booster and the stirrer.

As a result, the daily glass pulling amounts were 180 tons / day and 240 tons / day, respectively, and the replacement of the substrate was completed. That is, (maximum glass pulling amount (ton / day))
The value of / (ceramic glass possession amount (ton)) is 0.7 in the comparative example.
7, the value was significantly increased to 1.02 in the example. We were able to increase the speed of changing the substrate by 33%.

(Example 2) The color was changed from flint glass to green glass by the same kiln and method as above. In the comparative example, the colorant magnification is 1.4 times to 1.3 times the standard.
What was changed in 5 steps of 1.2 to 1.1 to 1.0 is 4.0 to 2.0 with respect to the standard in the embodiment.
It was completed in four steps of ~ 1.5 to 1.0, and the coloring time could be shortened. The actual color change time was 32 hours in the comparative example, whereas in the example, the color change was completed in 15 hours. It was also confirmed that product defects due to color unevenness did not occur in the examples and good products could be produced.

(Example 3) SiO ₂ 73%, CaO 12
%, Na ₂ O 13% glass to SiO ₂ 73%, Ca
The composition was changed to a glass containing 11% of O and 14% of Na ₂ O in the same kiln as above to compare with the conventional one. The result is C
Since there is a risk of composition unevenness (code) in carrying out aO → Na ₂ O substitution of 1%, it is divided into 3 steps and stabilized for 4 days each, then proceed to the next step and change over a total of 12 days. However, in the present embodiment, it could be completed with one change.

[0014]

EFFECTS OF THE INVENTION According to the present invention, even if the substrate replacement step is significantly changed, color unevenness, codes, etc. do not occur, and it is possible to replace the substrate in a short period while maintaining high quality. is there. In addition, as an additional effect, quality improvement in normal times can be expected sufficiently. Therefore, the present invention solves the conventional drawbacks and has the above-mentioned effects, and thus can sufficiently contribute to the industry.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention.

[Explanation of symbols]

1 Glass Melting Kiln 6 Electric Booster 2 Melting Section 7 Stirrer 3 Working Section 4 Feeder

Claims (1)

[Claims] 1. A glass melting furnace having a melting section, a working section and a feeder (glass pulling amount (ton / day) / ceramic glass holding amount (ton))> 1 (where, the kiln glass holding amount is the melting portion). The total amount of molten glass in the working part and the feeder) is forced by the plurality of electric boosters and / or oxygen burner sets provided in the melting part and the stirring devices provided in all the feeders. A method for accelerating replacement of a material in a glass melting kiln, characterized in that the amount of glass pulled and the homogeneity of the glass are improved.