The influence of water in the batch material on the furnace cannot be ignored

The influence of water in the batch material on the furnace cannot be ignored

Homogeneous mixing of batch materials is a prerequisite for optimal melting capability. The components of the batch are stratified and the flying material is very unfavorable to melting, clarification and refractory materials of the furnace. In order to eliminate these unfavorable factors, a certain amount of water needs to be added during the mixing operation of the batch material. Practice has proved that the moisture content of the batch material has a great relationship with its uniformity. It has the following functions.

 ① Adding water can make the surface of the sand wet and form a water film, which strengthens the ability to melt and adhere to the flux, and makes the reactants in good contact and accelerates the reaction process

②After adding water, the water will produce adhesive through the action of capillary suction to increase the viscosity of the batch, make the position between the particles stable, easy to mix evenly, and reduce delamination.

③Reduce dust, which is beneficial to protect the health of workers.

④ Moisture can increase the heat conduction during melting, making the batch material easy to melt.

⑤When the water is heated, it turns into steam and escapes, which can stir the glass liquid, bring out small bubbles, and promote the clarification and uniformity of the glass liquid.

 ⑥ Due to the reduction of flying materials, it can also reduce the corrosion of refractory materials and waste heat utilization devices of melting furnaces.

   In addition, moisture can reduce the surface tension and viscosity of the melt, which is also meaningful for the initial melting stage. Moreover, the infrared absorption spectrum band of OH group is just in the optimum range of thermal radiation at 1400℃. Therefore, increasing the H2O content can improve heat absorption, at least in melts with low iron content. The hydration degree of endothermic raw materials in the batch, especially Glauber's salt and soda ash, is also related to the temperature of the batch. In order to make water have good wettability and permeability, the temperature of the batch can be increased to above 35°C. Below 32°C, sodium carbonate combines into stable carbonic acid (Na2CO3·10H2O) with 10 crystallization waters; At 35.1°C, it decomposes into monohydrate sodium carbonate (Na2CO·H2O).

   Similarly, when Glauber's salt is below 32.4°C, sodium sulfate combines with water to form a stable sodium sulfate with 10 crystal waters (Na2SO4·10H2O). When the temperature is higher, it becomes anhydrous Glauber's salt. It can be seen that when the temperature exceeds 35°C, more water can be in a free state and fully play its role. Otherwise, a considerable part of the water will be hydrated and absorbed by soda ash and mirabilite immediately after entering the mixer to become crystal water. The material dries quickly and the moisture loses its beneficial effects. However, too much water will also bring many disadvantages: if the batch material is too wet, it will form eggs, which is not easy to mix evenly; the evaporation of water consumes a lot of heat and reduces the thermal efficiency; when the water is too much, it will bond the mixer and feeding equipment, which will bring difficulties to the operation.

   Therefore, when the batch is mixed, water and steam should be added to keep the temperature of the mixture at about 45°C. It is advisable to add water at 4%~5%, so as to inhibit the delamination of batch materials and reduce the generation of flying materials, thereby improving the melting capacity of the furnace and reducing the erosion of refractory materials caused by flying materials.