| 摘要 |
Process of Melting Silicate Raw Materials, Particularly in the Production of Mineral Wool, and Apparatus for Pre-heating the Mixture of Raw Materials and Apparatus for Purifying the Tank Exhaust Gases In the proposed process of melting silicate raw materials, the combustion air is preheated in two stages and the mixture of raw materials is preheated in one stage. After having preheated the mixture of raw materials, the tank exhaust gases are purified to remove dustlike and/or gaseous constituents, such as inorganic fluorides. At a temperature of, e.g., 1400.degree.C the tank exhaust gases enter a recuperative heat exchanger, in which the tank exhaust gases are cooled to about 600 to 650.degree.C and the temperature of the combustion air which has previously been preheated to 130 to 180.degree.C is increased to about 950.degree.C. The mixture of raw materials is received in a container and is subjected therein to a heat exchange with the tank exhaust gases, which are thus cooled to 300 to 350.degree.C. the tank exhaust gases are then supplied to a purifying apparatus and are subsequently used in a regenerative heat exchanger to preheat the combustion air. As a result, the tank exhaust gases are cooled to about 150.degree.C. This will not involve a risk of a formation of acid in the heat exchanger or in the chimney because the gases have previously been purified to remove aggressive gaseous impurities. During the heat exchange with the mixture of raw materials, some impurities, such as fluorine, are filtered out and are then charged with the mixture of raw materials into the melting tank. |
