HEATING METHOD OF CONTINUOUS ANNEALING FURNACE FOR METALLIC STRIP

摘要

PURPOSE:To heat a strip in a manner as to adapt itself to the thickness change thereof by injecting a gas which is adjustable in temp. and flow rate to both or one side of the strip in a short period. CONSTITUTION:The strip 1 is heated only by the radiant tubes in the stage of stationary operation. The combustion rate of the radiant tube burners is increased when the thickness of the strip 1 increases. Gaseous HN is at the same time supplied from the bottom of a pebble heater 11 through a dust 13 and the gas heated to a high temp. is supplied to a plenum chamber 2. The gas is injected from gas jet nozzles 3 to both or one surface of the strip 1 so that the strip 1 attains the prescribed temp. in a short period. Part of the gaseous NH is bypassed when the thickness decreases. The mixing ratio of the gas in the heater 11 is then adjusted and the gas of low temp. is supplied for a short period.