The Tongliao "Target Kiln" was officially put into operation on November 15, 1992. After 4 years of operation, all parts of the furnace are in good condition.
Pool wall
The pool wall bricks used are domestically made 33# oblique pouring fused AZS large bricks with a thickness of 250mm and 200mm. Due to the good quality of the bricks and proper guarantee measures, the pool wall has been operating normally.
After more than 4 years of operation, the state of the pool wall is roughly as follows. The entire kiln pool wall has different degrees of erosion at the liquid level depending on the location. The law is to gradually reduce from the front to the back. 30~50mm; the clarification zone is the second place, eroding about 80~120mm; the most serious is the melting zone, eroding about 150~260mm. Among them, near the 2# small furnace, the molten glass has begun to contact the tied bricks, but due to The time is relatively short, only eroding about 10mm. If no accidents occur, the cold repair period of 1998 can still be maintained.
In addition, brick materials imported from Japan are used at the corner of the pool wall. From the perspective of erosion, the corner of the feeding pool is heavier than the entrance corner of the card neck. It is estimated that the erosion depth is about 150~200mm. However, due to the external water bag and air cooling, it is expected to be synchronized with other parts.
parapet
The most severe erosion of the parapet wall is the parapet wall in the melting zone. Although the parapet wall is made of 33# fused AZS bricks, the heat load is concentrated and the burning is still serious. Many of the hook bricks of the parapet have been broken from the protruding part. It is a threat to the pallet of the breast wall. In addition, the gap between the parapet wall and the large ballast and the gap between the parapet and the small furnace vent also has multiple fire penetration phenomena, and some have burned through large holes, which will directly threaten the steel ballast and other iron. The safety of the parts is also difficult to handle due to conditions. So far, it has only been simply blocked and air-cooled, and has not been completely resolved. However, under the premise of enhanced maintenance, cold repair of this part should not be a problem until 1998.
Dam
The material used by Dajing is domestic high-quality silica bricks, which are still in relatively good condition. Especially the large chute at the end of the cooling part and the clarification zone, there is almost no erosion, and it is estimated that the depth of burning will not exceed 50mm. Therefore, the next cold repair is expected to be reserved for use.
The large turret in the melting zone is the main damaged area. Due to the use of 5 pairs of small furnaces, the heat load is excessively concentrated, so the burning of the turret head and the hot spot is the most serious. There have been phenomena such as individual brick lottery and fire-through on the bricks of the tutou. After repairing and adding wind, it has basically been controlled. The large chrysanthemum near the hot spot has already appeared chrysanthemum droplets in the early stage of production, and the surface has a slight honeycomb shape. After operation and adjustment, the erosion rate gradually becomes normal. However, due to inadequate sealing of individual brick joints, there is still a phenomenon of digging holes. Although they are timely sealed, they are totally unrecognizable from the appearance.
Especially when the sea blue glass was produced in April 1996, due to the change in the heat absorption rate of the batch material, and no ideological preparation beforehand, the temperature of the top of the dome was obviously increased, and the burning was very serious, and a large area of ??brick skin fell off. Phenomenon, it is estimated that the burning depth can reach about 100~150mm; obvious pits have appeared on the inner surface, and the droplets and honeycombs are relatively large. However, for the 450mm thick kiln brick (kiln width 9.5m), if the Well, if there are no major accidents, it should be used until the 1998 cold repair period.
L-shaped hanging wall and card neck hanging wall
Both the L-shaped hanging wall and the card-neck hanging wall used by the Tongbo float method are a complete set of products imported from the American Mork Company. After more than 4 years of use, the steel structure is relatively intact, but the brick structure has varying degrees of damage.
L-shaped suspended wall: During the first two years of operation, it was basically relatively intact. In the third year, the bottom sintered AZS showed signs of erosion, and the transverse joints between the upper silicon brick and the lower sintered mullite brick increased. The fused AZS head protection bricks on the ribs on the north and south sides also appeared to fall off, and now the fall off area is about 1 square meters on both sides. The burning damage of the lowest silicon bricks on the north and south sides is particularly serious. Several bricks on the south side have been broken and pits have appeared, but the fire has not been penetrated so far. On the north side, 6 to 8 bricks fell through the fire. After repairing, they are still in normal use.
Card neck hanging wall: After being put into operation, it has been relatively normal. However, after the occurrence of accidents such as mixing and water leakage, the damage was great, causing some bricks to burst and slightly sink. After nearly two years of burn damage, a large area of ??fracture and subsidence occurred. The sinking part accounts for about 70-80% of the entire suspended wall, and the sinking height is 250-300mm. Since it could no longer be restored, it had to be destructively sunk into the kiln. However, the remaining part is still relatively strong, which will affect the sealing, but it just can no longer play the role of space separation.
Small furnace
In this part of the small furnace, all 33# fused AZS bricks are used, and some parts also use non-shrinkage bricks. After 4 years of use, except for the small furnace mouth, other parts have burnt to a certain degree, which is not Affect its service life. Only the small furnace vent, especially the flat vent, is more dangerous. Because the vent flat bricks are non-shrinkage bricks, and the bricks are relatively large and special-shaped, it virtually brings a lot of difficulties to the production and processing. Therefore, some of the flat bricks produced under the conditions at that time basically met the standards, but there were still small cracks. After being put into use, due to various changes, some micro-cracks developed and expanded, and even caused damage. Among the 5 pairs of small furnaces, nearly 1/3 of the small furnace flat caskets showed different degrees of cracks or damage. Among them, the 3# small furnace on the south side is the most prominent. A set of five bricks, starting from the beginning of 1994, has been broken in half along the vertical direction one after another. Secondly, there is a brick in the small furnace flat in the north 1#, and a corner of the brick was broken in February 1997, and there are obvious cracks in the adjacent bricks. In addition, other small furnaces, such as North 3#, South 2#, etc., also have individual bricks with cracks.
Small furnace hook bricks, nozzle bricks and nozzle spacer bricks are also damaged severely. Many hook heads of the hook bricks have been burned, which aggravated the burning damage of adjacent parts, but they could not be handled. Since February 1994, nearly 15 nozzle bricks have been replaced so far. The operation is relatively easy, while nozzle spacer bricks are quite difficult to replace. So far, only one has been replaced. Although there are other serious burns, they can only be used by maintenance. In other words, although the small furnace hook bricks, nozzle bricks and spacer bricks are severely burned, they will not cause excessive influence on the use.
Regenerator
The regenerator is a very important link related to the service life of the furnace. Although the structure and materials used were carefully considered and reasonably matched in the design, due to the influence of many factors, many abnormal situations occurred in the use of the regenerator.
The target wall of the regenerator. The selected material is directly bonded magnesia chrome brick containing MgO>55% and Cr2O>20%. This material was a newly developed product in China at that time, and there was no practical experience in using it. After being used on the target wall, the temperature at the location is relatively high and the temperature changes more frequently, so the material itself is changing from beginning to end, causing some of the bricks to peel off, and the severely damaged area can now reach more than 100mm.
Regenerator lattice body. The materials used in this kiln period are all alkaline materials, of which the upper and middle parts are high-purity magnesia bricks, and the lower part is directly bonded magnesia-chrome bricks. During use, the damage of the upper brick material and the lower brick material is more serious. Especially after 1995, the surface of the upper checker bricks began to blur, and the bricks peeled off and the positions were disordered. Part of the grid is blocked as a result. The main problem of the lower grid body is that the alkaline fly material is solidified here, which causes the grid holes to be blocked, which requires repeated treatment, which causes great damage. Over the past four years, ten heat-pass regenerator work has been carried out. Now the difficulty in handling it has become greater and greater, and the effect has not been as good as once. The damage to the directly bonded magnesia-chrome bricks in the lower part is also very serious. Many bricks have broken, and some have caused partial collapse, which is very difficult to handle. We believe that the serious blockage of checker bricks is directly related to the too small lattice holes. Enlarging the lattice holes in the design will play an important role in prolonging the service life of the kiln body.
In addition to the above parts, other parts of the kiln have burnt to varying degrees during the more than four years of use, but they are all normal phenomena and will not have much impact on the service life of the entire kiln. To sum up, after 4 years of operation, the whole kiln can be used in all parts except for the small furnace vent flat chute and grid body and other critical parts that are dangerous.
Process control
1. Use heavy alkali;
2. Control the content of ultra-fine powder in siliceous raw materials;
3. Ensure the moisture content of the batch;
4. Realize thin layer feeding;
5. Strictly control the flame angle.
