Alkali-free fiberglass pool kiln
The kiln type of alkali-free fiberglass pool kiln is a unit kiln. The melting pool is long and narrow, and the length-to-width ratio is generally around 3.5:1. The distance that glass production goes through from melting, clarification to homogenization is 2 to 3 times that of other kiln types. The glass melting and clarification in this melting pool has a long melting and clarification journey and a high melting temperature, which is suitable for melting refractory and high-quality alkali-free glass. Connected to the kiln pool are the main passage and the operating passage, which receive the molten glass flowing from the melting pool flow hole or the channel under the retaining brick, gradually cool it down and keep it constant, and after reaching the appropriate temperature, it flows into the wire drawing leaky brick for wire drawing.
The unit kiln is the heart of a fiberglass factory that uses the tank kiln method. When the refractory materials used in its construction are corroded to a certain extent, the unit kiln cannot maintain production and must be shut down for cold repair. Therefore, the refractory materials used in the construction of the unit kiln must have excellent high temperature resistance, thermal shock resistance, and resistance to erosion and scouring by glass liquid, furnace gas, flame and powder. The variety and quality of the refractory materials selected play a very important role in increasing production, saving fuel, reducing costs and extending the life of the kiln. Therefore, how to match refractory materials is the key to tank kiln design.
The refractory bricks used in the glass contact area are required to have:
(1) Good corrosion resistance of glass:
(2) No bubbles, gravel, streaks, knots, coloring and other glass defects will be caused, and no contamination of the glass solution will be caused. Refractory materials containing Cr2O3 are the best among all refractory materials in terms of chemical corrosion resistance. However, due to its major disadvantage of coloring the glass texture, it can only be used in kilns that produce glass fiber and amber and emerald green glass where coloring is not a problem.
The refractory bricks in the parts that do not contact the glass, such as the ceiling and heat storage chamber, also affect the quality of the glass and the service life of the glass kiln. In order to melt glass containing low-melting-point oxides and improve the thermal efficiency of the tank kiln, it is necessary to develop refractory materials with excellent performance for heat storage.
Since the alkali-free glass fiber tank kiln needs to operate for a long time, the refractory materials used are very important. At present, the production technology development of alkali-free glass fiber is centered on the following aspects:
(1) Improving the refractory material's resistance to alkali-free glass corrosion;
(2) Increasing the pollution resistance of the glass melt;
(3) Reducing the pollution of the production process and the selection of refractory materials to the environment;
(4) Reducing the defective rate and stabilizing product quality;
(5) Improving the heat storage capacity of the tank kiln and saving energy.
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