1992 "Target Kiln" (1) Design and Construction of Tongbo Float
The Inner Mongolia Tongliao Glass Factory (acquired by Fuyao in 2003 and now Fuyao Group Tongliao Co., Ltd.) float glass production line that was ignited on September 1, 1982 is the second float glass production line designed by my country after the Luoyang float production line. , Became the first float glass production line designed and produced by ourselves in the true sense of our country.
Although the daily melting capacity has been increased from 205t/d to 270t/d after two reforms, due to the limitation of domestic technical conditions and the performance and quality of refractory materials at that time, the structural design of the melting furnace has been restricted to a certain extent, and some necessary energy-saving technologies are also restricted. Failure to adopt it in time has resulted in many drawbacks in the glass melting furnace.
For this reason, in 1992, the Qinhuangdao Glass Design Institute took the lead in carrying out a large-scale energy-saving technological transformation of the furnace. It is the first time to adopt the Toledo melting furnace technology of the United States and the first use of computer networking in the glass industry to control the production process of the three major thermal equipment, which has been increased from 270t/d to 400t/d, which is very effective in terms of energy consumption, quality and efficiency. . After the project was put into operation on December 15, 1992, it played a demonstrative role in the glass industry, bringing my country's glass melting furnace technology and automatic control technology to a new level, and won the National Design Gold Award in 1996.
1992 Tongbo Float Furnace is the first targeted melting furnace in my country that is built using the country's imported advanced melting furnace technology and automatic control technology.
Tongbo's "Target Kiln" was ignited on November 15, 1992, and was cooled with water on April 16, 1998. After 1970 days of operation, it overfulfilled its historical mission. In addition, with its advanced furnace structure, high-quality supporting refractory materials, and reasonable and effective use and maintenance, the overall design goals of improving glass quality, reducing energy consumption, extending furnace life, and increasing economic benefits have been achieved. Thus, the leading position of Tongbo's "target kiln" in the country was undisputedly determined at that time, and it also fully demonstrated the important role of the "target kiln" as an example.
Technical transformation of Tongliao float glass melting furnace in 1992
Based on the principle of energy saving, high efficiency, and improving production quality,
1. Adopt foreign advanced furnace structure and control method;
2. Choose high-quality refractory materials to match;
3. Implement full heat preservation of the furnace. In order to reduce heat loss, improve heat utilization, and then use energy more rationally.
The main technical and economic indicators are compared as follows:
Improvement of glass melting furnace structure
The main dimensions of each part of the melting furnace are selected based on comparison and optimization based on the Toledo Company (teco.com), the "Seventh Five-Year Plan" research results, and the production practice experience of domestic float furnaces and necessary theoretical calculations.
After that, my country’s Glass Industry Design Institute introduced the float glass melting furnace design technology of Toledo Company of the United States, and made some corresponding improvements and enhancements to the structure design of my country’s melting furnaces, making my country’s glass melting furnaces pursuing high-quality At the same time, it is gradually developing towards the direction of low energy consumption, high thermal efficiency, large-scale and long kiln life, shortening the gap with the world's advanced level.
For the characteristics of TECO furnace technology, please refer to "Analysis of the Structural Characteristics of TECO Float Glass Furnace" written by Zuo Zefang (currently the deputy chief engineer of China National Building Materials International Engineering Corporation) in 1998, Bengbu Glass Industry Research Institute
Structure
1. Feeding port
The upper structure of the feeding port adopts the second-generation front face hanging wall L-shaped hanging wall structure of American Mork Company. It has the characteristics of structural safety and stability, and can widen the feeding surface, which is conducive to melting. The 45° inclined part of the lower part of the L hanging wall is conducive to the radiation heat transfer of the flame and can play a pre-melting effect on the batch; the bottom of the L hanging wall is close to the material surface, which is conducive to the sealing of the feeding pool, improving the working environment and reducing heat loss. At the same time, the L-shaped hanging wall is matched with the lengthening of the distance from the 1# small furnace to the feeding pool, which can increase the load of the 1# small furnace, so that the batch material is in a high temperature state as soon as it enters the kiln, which accelerates the melting of the batch material; Reduce the erosion and blockage of the front-end regenerator grid by the flying material, which is beneficial to prolong the life of the grid.
2. The bottom of the pool
In order to ensure the quality of molten glass, the bottom of the melting furnace adopts a shallow flat bottom, and ramming material and paving tiles are added to the bottom of the melting part and the neck of the pool to facilitate sealing and reduce the pollution of the molten glass. The pool depth is changed to 1.22m, which is shallower than the traditional pool depth in China. The immovable layer of the molten glass at the bottom of the kiln is reduced, and the reflux of the molten glass is reduced, and repeated heating of the molten glass is avoided, which is conducive to energy saving and improves the melting rate.
3. Melting part
The steel structure of the melting part is similar to that before the transformation, except that the column adopts a wide-flanged H-shaped steel single column structure; and a water cooling device is added at the position where the bending moment is large, which increases the strength of high-temperature work and helps to maximize the relaxation. Mouth. The big ballast is still steel ballast. The melting part adopts a new type of upper structure, as shown in Figure 1 and Figure 2. The upper and lower gap bricks are eliminated, and the breast wall is integrated with the big chute; the gap between the hook brick and the upper edge of the pool wall is small, and it is plugged with a sealing material. This strengthens the airtightness and integrity of the kiln body, which is conducive to energy saving and the safety of the kiln body structure.
In order to obtain high-quality molten glass, a sufficiently long clarification zone is determined based on the calculation of heat balance and the bubble discharge speed, which strengthens the high-temperature clarification and homogenization of the molten glass, ensures sufficient bubble discharge time, and effectively improves the glass. Liquid quality.
The whole wall of the kiln adopts the method of erecting the whole brick, which has changed the practice of multi-layer horizontal masonry used in our country. Therefore, the impact of corrosion at the horizontal brick joints on the life of the refractory is avoided. At the same time, the processing precision of bricks is relatively high, and the masonry is tight, which also reduces part of the heat dissipation loss.
4. Card neck
While adopting a narrow card neck, it is equipped with a hanging flat hanging structure. The space connection between the melting part and the cooling part is separated to the greatest extent, and the fluctuation of the kiln pressure and temperature of the cooling part caused by the pressure fluctuation of the reversing kiln is reduced, and the heat loss of the melting part is effectively reduced. In addition, a vertical stirrer and cooling water pipe are also installed here to improve the chemical uniformity and thermal uniformity of the glass liquid, and improve the quality of the glass liquid.
5. Cooling part
The cooling part has not been modified too much, but a set of dilution air system is added, which can be used to adjust the kiln pressure and temperature system of the cooling part to meet the requirement that the temperature fluctuation of the formed glass liquid is not more than ±1℃. In addition, a pair of light oil spray guns can be installed to meet the needs of producing colored glass.
6. Small stove
On the premise of ensuring melting, only 5 pairs of small furnaces are set up. And according to the different loads of the small furnaces, different small furnace widths are designed from large to small. It not only expands the flame coverage area and strengthens the melting process; but also the fuel consumption among the small furnaces is reasonably distributed, which enhances the fuel combustion effect and effectively utilizes energy.
7. Regenerator
The box-shaped connected regenerator is adopted, the partition wall in the regenerator is eliminated, the grid body is heightened, and the heat storage area is increased; high-quality refractory materials are used to improve the heat storage capacity to ensure the full use of waste heat.
8. Flue
Adopt TECO SUPERFLUE® super flue system (the glass furnace flue system is rarely used nowadays), each small furnace corresponds to a branch flue, and the air enters on the branch flue, and the main air pipe changes direction. The intake air ratio of each small furnace is adjusted on the branch flue air intake branch pipe, and the flue gas ratio is adjusted on the branch flue.
9. Kiln body insulation
In the glass kiln, about 30% of the heat loss is lost to the environment from the surface of the kiln body. For this reason, the newly renovated glass float kiln adopts a full thermal insulation structure of the melting kiln. In addition, reasonable selection and matching of the insulation materials used are carried out to maximize the insulation effect. The heat preservation parts mainly include the big chute of the melting part, the breast wall, the pool wall, the pool bottom, the small furnace, the regenerator, etc. The materials used mainly include lightweight silica bricks, clay bricks, non-asbestos calcium silicate boards, aluminum silicate fiber felts and rock wool boards.
Full kiln refractory configuration
The transformation of the furnace structure is largely limited by refractory materials. At that time, the performance and quality of refractory materials for glass kilns in our country had a big breakthrough, and the supporting applications were basically mature.
Through the most reasonable configuration, we strive to synchronize the life of refractory materials in all parts; reduce glass defects caused by refractory materials to a minimum; long life of the furnace; low energy consumption; advanced technical and economic indicators; the entire furnace is stable The best operating condition.
The specific usage is mainly manifested in:
(1) Imported bricks are used for the L-shaped hanging wall, card-neck hanging flat chute and the corner of the pool wall.
(2) The bottom of the whole kiln is casted with large clay bricks, and zircon ramming layer and sintered AZS paving bricks are added to the bottom of the melting part. .
(3) The wall of the whole kiln is 33# oblique casting electrofusion AZS by monolith oxidation method, and the key part is non-shrinkage electrofusion AZS.
(4) All the main bricks used for large slabs are high-quality silica bricks.
(5) α-β and β-corundum bricks are used near the overflow.
(6) All small furnaces use oxidation method 33# fused AZS bricks.
(7) The target wall of the regenerator is directly combined with magnesia-chrome bricks. The lattice body uses high-purity magnesia bricks containing 97% and 95% MgO and directly bonded magnesia-chrome bricks.
