Alkali-free glass fiber pool kiln

The kiln type of alkali-free glass fiber 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 process and a high melting temperature, which is suitable for melting refractory and high-quality alkali-free glass. The main passage and the operating passage are connected to the kiln pool, which receive the molten glass flowing from the flow hole of the melting pool or the channel under the retaining brick, gradually cool it down and keep it constant, and then flow it into the wire drawing leak brick for wire drawing after it reaches the appropriate temperature. Figure 1 is a plan view of the alkali-free glass fiber pool kiln.

The unit kiln is the heart of a glass fiber factory that uses the tank kiln method. When the refractory materials used for 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 to build 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 used play a very important role in increasing production, saving fuel, reducing costs and extending the life of the kiln. Therefore, how to match the refractory materials is the key to the design of the tank kiln.

The refractory bricks used in the glass contact area are required to have:

(1) Good corrosion resistance of the 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.

Refractory bricks in 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. Table 1 lists the typical refractory lining configurations for various parts of the tank kiln.

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 development of alkali-free glass fiber production technology 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.