| 摘要 |
Industrial furnaces for heating or heat-treating workpieces have a furnace chamber serving to receive the workpieces, a multiplicity of fuel-fired burners for direct heating of the furnace chamber and a recuperation device for preheating the combustion air flowing to the burners with the aid of the hot exhaust gases withdrawn from the furnace. In order to increase the efficiency of the industrial furnace and to ensure perfect control of the furnace atmosphere, a separate recuperator (15) is arranged upstream of each individual burner (3) or individual burner group and an air control valve (17) is provided in the cold air line (11) upstream of each recuperator (15), by which the cold air flow rate to be fed to each burner (3) can be adjusted. As a result of the multiplicity of the relatively small recuperators, a more favourable heat utilisation is possible and, in addition, the flow rate of combustion air per unit of time can always be held exactly constant independently of the degree of preheating. <IMAGE> |
