How to choose refractory material in the part of glass melting furnace lining molten part?

Most of the refractory materials directly exposed to the glass are subject to diffusion or permeability, which is characterized by liquid erosion. The temperature of sodium calcium glass can reach 1500 degrees. The temperature of other glass liquid depends on the requirement of glass viscosity and the composition of glass, or above 1500 degrees, or less than 1500 degrees. The most important thing for refractories that are directly exposed to glass is the performance of corrosion resistance. For colorless glass, it is a serious problem to be contaminated with refractory materials.

In the melting zone of some small melting kilns, refractory materials produce gas or bubbles, which is also an important problem. Generally speaking, only the refractory material at the front end of the furnace can release the gas to affect the quality of the products.

In normal operation, the temperature of the direct contact with the glass liquid is relatively warm, but the thermal shock resistance of refractory materials is particularly important in the kiln or the cool kiln.

On how to select the refractory, much depends on the glass composition and suffered from the exposed surface of glass erosion compared with horizontal exposed surface, vertical wall has exposed surface, formed on the surface of the particles will flake off under the action of gravity and material selection on the wall is more important.

1, the side walls

The side wall of the single layer is in the position of the liquid level of the glass liquid, and the rate of erosion is faster and higher. The surface of the glass can be cooled by external air. Thermal insulation materials can be used below the liquid level. Refractory clay bricks can be selected to prevent the glass liquid from corroding the insulation materials through the cracks between the bricks. The erosion degree of the glass liquid level influences the service life of the wall brick, and the rate of erosion changes with the temperature in the melting furnace. Cooling on the liquid level can slow down the erosion of side wall tiles. There is no liquid level line in the whole electric melting furnace, and the degree of erosion is relatively uniform.

Brick joints are the weak parts of the furnace, erosion degree is higher, therefore, in direct contact with the part of the glass should choose big brick to reduce brick seam, melted different glass can choose different refractory material.

In the two-layer or multi-layer structure, the horizontal brick seam between the layers is susceptible to upward drilling, and the degree of upward drilling is determined by the size of the horizontal brick seam.

2. Feeding end wall.

The environment is basically the same as the wall of the pond, and the gas will be released when the material is melted, which will cause a large turbulent flow of the glass liquid, which may cause erosion to the glass liquid surface area. Due to the movement of the material layer, the radiation heat is covered, which makes the temperature change dramatically. The selection of refractory materials can be consistent with the wall of the tank.

3. Feeding port

The continuous feeding is less, the temperature fluctuates greatly, and the temperature fluctuation of refractory material can be caused by discontinuous feeding. After the clinker is put into the melting furnace, it may cause some erosion or wear.

4. Fluid hole

The bridge wall and the lattice wall are used to realize the thermal transformation of the glass in the system from melting zone to the clarification zone and the distribution of glass to each molding machine. It is the most vulnerable part in the melting furnace. In the standard flow hole structure, the cover brick and the face brick and the glass contact surface have a large area.

The area is more uniform, and dense refractory materials should be used, and the selection of dense refractory materials is also conducive to cooling measures.

Stone of this part is the furnace to produce one of the most sensitive areas, caused by drilling and erosion corrosion product to flow out into the glass, when choosing materials should choose the strongest erosion resistance of refractories, the different system of molten glass also can choose different refractory material.

5. Bridge wall/end wall.

Close to the fluid hole, it is easy to bring defects to the glass. When there is a lack of good air circulation between the melt belt and the clarification zone, the temperature will be higher.

6, bridge wall

The furnace in the melting zone is cut down, and the two sides are exposed to the glass solution, which is eroded rapidly and lacks the protective thermal gradient to reduce the surface temperature and reduce the erosion. Because of the rapid erosion, it is possible to produce streaks and stones.

7, kiln bottom

The most vulnerable to liquid erosion, less drilling. The erosion product will remain on the surface under the action of gravity, and can be used in the selection of refractory refractory materials. It is easy to make glass defective in the convection of molten glass and the load in the kiln.

At the bottom of the kiln, a local turbulent flow will be generated, and better anti-erosion resistant materials should be selected in this area. In accordance with the habit of the kiln floor tile, it can avoid the disturbance caused by the layered structure by using the thick molten cast refractory material and the balance of the life of the furnace.

Mixed with metal impurities on the batch of glass kiln bottom structure will have a serious impact, the metal deposit in the bottom of a kiln, most easily eroded the bottom of the kiln, only in rare cases, metal will be restored directly in the glass.