Extraction of melting furnaces and cupolas
PROBLEMS OF THE EXTRACTION PROCESS OF MELTING FURNACES AND CUPOLAS
Flue gas extraction from melting furnaces is one of the most important extraction systems in foundries, smelters and ironworks. The melting of metal produces large quantities of flue gases, which must be extracted by a performance-stable extraction and filtration system. Flue gas extraction from melting furnaces is divided into hot and cold applications according to the temperature of the exhausted flue gas. Hot flue gases are generated in gas melting furnaces, cupolas and rotary kilns. The temperature at the furnace outlet is around 350 to 500°C.
For the extraction and filtration of the flue gases, it is necessary to use either filter units of special construction, equipped with ceramic filter media with a heat resistance of up to 900 °C, or to cool the flue gases before filtration with a textile filter. Industrial tube coolers or recuperators are used to cool the exhaust gases to a temperature suitable for filtration with a textile filter. Cold flue gases are extracted from electric induction furnaces. In electric induction furnaces, the flue gases are not produced by the combustion of gas or other fuel, but the molten material is gradually heated by electric induction.