CONTINUOUS LEHR FOR THE HEAT TREATMENT OF GLASS-BASED MATERIALS

1,198,202. Heat treatment furnaces. ORDENA TRUDOVOGO KRASNOGO ZNAMENI ZAVOD AVTOSTEKLO. 16 April, 1968 [14 April, 1967], No. 17844/68. Heading F4B. A continuous lehr for the heat-treatment of glass-based materials comprises a heating chamber 1 having a conveyer 9 passing therethrough, the upper part of said heating chamber being directly heated by combustion products emerging from outlet ports 10 of gas burners 12, whereas the lower part is heated by products of combustion delivered into the heating chamber from combustion chambers 14 via holes 15 in a hearth grating 4. Along the length of the heating chamber 1, the combustion chambers 14 are separated by cross-partitions while in the longitudinal direction these chambers are subdivided by partitions 17 into two parallel ducts 14a and 14b. Between the crosspartitions of two adjacent chambers 14 vertical flue ducts 19 are provided, closable by slide dampers 18. From the upper part of the heating chamber 1, the products of combustion are removed through vertical ducts 23 provided in the roof 3 of the heating chamber and closed by slide dampers 22. The heating chamber may be subdivided into several working compartments by means of cross-partitions (28, Fig. 2) having apertures (29) to let the material in the form of a strip 31 pass along the conveyers. The temperature conditions in the lehr are controlled by means of thermocouples mounted in the heating chamber 1 and the combustion chambers 14; the atmosphere within the lehr is controlled by means of pressure indicators and is adjusted by means of the slide dampers 18 and 22.