Abstract: A swirl burner of the two-stage combustion type with suppressed NO.sub.x generation which is so arranged that combustion air supplied into the burner is divided into primary and secondary combustion air, and the primary combustion air subjected to a powerful swirling motion by a primary combustion air nozzle having a frusto-conical shape and swirling vanes is supplied into a primary combustion chamber for drawing only primary combustion gas thereinto, while the secondary air is directed, in the form of a rectilinear flow, into a furnace through secondary combustion air nozzles provided around the primary combustion chamber, with oil and gas for fuel being supplied into the primary combustion chamber through a fuel injector nozzle. Part of the fuel is burned in the primary combustion chamber, while the remainder of the fuel is sequentially mixed with the secondary combustion air for combustion in the furnace.

Abstract: A heating method of operating a furnace in a hot rolling line and a heating furnace therefor in which the reheating furnace is positioned between a continuous casting apparatus and a rolling apparatus rolling workpieces at a higher speed than they are cast by the casting process, the furnace serving as a heating and buffer zone. The reheating furnace includes at least three moving beams each having an independent driving mechanism, and coupling mechanisms which couple the neighboring moving beams for independent or synchronous movement, while the moving beams are so arranged that, by operating the driving mechanism, they are altered in their speeds to the discharging speed of the workpieces from the continuous casting process, or one or two of the moving beams are brought into idling state or driven at the rolling speed.

Abstract: A method of operating a reheating furnace in a hot rolling line and a heating furnace therefor in which the reheating furnace is positioned between a continuous casting apparatus and a rolling apparatus rolling workpieces at a higher speed than they are cast by the casting process, the furnace serving as a heating and buffer zone. The heating furnace is longitudinally divided into two heating sections which are changed over so as to receive workpieces for heating and the workpieces are charged into one of the two sections after the other of the two sections has been filled up. The furnace is operated to collectively forward the workpieces heated up to predetermined rolling temperatures to the rolling apparatus for efficient rolling.

Abstract: There is disclosed a method for incineration of chromium-content-containing sludge and an apparatus therefor, in which the sludge is incinerated into ashes containing hexad chromium, which is, then, introduced into reducing gas to reduce the hexad chromium into triad chromium and, in turn, is cooled to stabilized the triad chromium, thereby to render to make the sludge harmless for discharging to the outside.