Fiberglass kilns and refractories thereof

Glass fiber is glass in the molten state, by external force or other methods to form a very fine fibrous material. Its basic properties are: non-combustible, non-decay, high temperature resistance, sound absorption, heat insulation, good electrical insulation, light weight and high strength, good chemical stability, a certain brittleness, etc. Fiberglass and its products are widely used in industry, agriculture, construction, furniture, transportation, aviation, aerospace and other fields, such as manufacturing fiberglass.

The glass fiber can be divided into three types: continuous (length > BBB>00mm), fixed length (500-300mm) and glass wool (< 300mm). The continuous fiber with monofilament diameter of 3~9 m can be processed into glass yarn, cloth, tape, etc. Monofilament diameter of 10~19 m of continuous fiber can be processed into non-woven or less textiles, such as roving, felt, etc. Fibers of fixed length can be used for waterproof, filtration and thermal insulation. Glass wool can be used as felt, board, paper, etc.

The chemical composition of glass fiber is divided into four categories: no alkali, alkali, high alkali and special glass fiber. Alkali - free fiber is also known as E glass fiber. It is R₂O content 0~2% aluminum borate glass, with good electrical insulation performance, fire resistance and mechanical strength. In the alkali fiber (C glass fiber) is R₂O content 8%~12% containing boron sodium calcium silicon glass. Its cost is lower than non-alkali glass fiber, used in the manufacture of latex cloth, window screen, acid filter cloth and strength requirements are not high reinforcement materials. High alkali fiber (A glass fiber) for R₂O content 14%~17% sodium calcium glass fiber, pipe wrapping Bucher asphalt felt base cloth, etc. Special glass fiber guide into ZRO ₂ and other made of fiber with special properties, such as high elastic modulus fiber, radiation proof glass fiber, etc.

Borate containing glass has a strong corrosive effect on refractories. The corrosion resistance of chromium oxide brick is the best, followed by dense zirconia brick, zirconia brick, and alumina brick is the worst.

Alumina material corrosion resistance is very poor, electric fusion AZS brick is easy to produce ZRO ₂ stones. Glass fiber is not taboo CR ₂O₃ coloring, but is very sensitive to stones. Stones may block leaks and cause production problems. Therefore, high erosion parts of continuous glass fiber kiln should use isostatic pressing, sintered fully chromium oxide brick, medium and low erosion parts should use dense zirconia brick.

In the production of glass wool, the diameter of the leakage hole is larger, and the possibility of the leakage hole being blocked is smaller. So, electric fusion AZS bricks can be used. At this time, the flow hole can be formed by isostatic pressing chromium oxide brick or electric fused brick containing 27% chromium oxide +27% zirconia. Side wall can contain 27% chromium oxide +27% zirconia electric fused brick or 41 AZS electric fused brick; Common 33 AZS electric fused brick with no shrinkage hole can be used at the bottom.

Because boron oxide greatly affects the high temperature performance of alkaline refractories, the lattice materials used in regenerators have high requirements for high temperature strength, softening temperature under load and creep resistance. Therefore, magnesia refractories should not be used as latticed tiles in kilns producing alkali-free and medium-alkali fiberglass.

The fused AZS brick is the most important refractory material for glass kilns. The high fused zirconium brick has a small stone tendency and is suitable for the key parts of making high quality glass kilns. Electrofused AZCS tiles are suitable for key parts of glass kilns that are not sensitive to chrome coloring.

The biggest advantage of melting αβ or β-alumina material is that it has no obvious harmful effect on the quality of glass, and it has good resistance to the erosion of sodium calcium glass or alkali vapor at 1350℃. Therefore, it is widely used in the cooling part of glass kilns.

Silica brick is widely used for masonry glass kilns due to its low cost and good creep resistance. In addition to the conventional properties, the high quality silica brick for glass kiln also requires the true density reflecting the degree of quartz transformation, the rate of change of the refiring line, and the silicon oxide content and melting index, which affect the long-term high temperature performance.

Alkaline refractories are widely used to make lattices because their price is much lower than that of fused AZS materials and their high temperature performance is good. Magnesium zirconium bricks used in glass kilns are significantly different from those used in cement kilns. The former in magnesium olivine - oblique zircon as the main matrix components, focusing on improving the resistance to SO₂ erosion; The latter is mainly composed of magnesite, which can improve the resistance to CaO erosion.

Sintered AZS materials can replace fused AZS materials in areas where erosion is less intense. Cracking resistant zirconium brick is used as a transition material between AZS and siliceous materials. Dense and high density zirconia bricks are used in the lower and moderate erosion parts of fiberglass kilns, respectively.

Tin trough bottom brick can be made of clayey material by the method of ramming or ultra-low cement vibration molding + sintering. The advantages of vibration molding are high production efficiency, high product density, apparent porosity and hydrogen diffusion index, good uniformity of structure, stable performance. Tin trough bottom brick made by vibration molding of ultra-low cement has been successfully developed and mass-produced in China.

Clay bricks are used for masonry where there is little erosion and no contact with liquid glass. Low porosity clay brick is used for masonry of low Wengeng subbody. The clay bricks at the bottom of the pool are made in a very similar way to the clay bricks in the tin trough.

Zirconite or AZS ramming material is used to fill the middle of the pavers and large clay tiles at the bottom of the pool.

In addition to the most severely eroded parts (three-phase interchange of the wall, liquid flow hole) need to be cooled, other parts of the glass kiln are taken insulation measures. Insulation is also important for extending the life of large crown. Insulation can be used as much as possible calcium silicate board.