APPARATUS FOR PREVENTING FLUE GAS OF REHEATING FURNACE FROM FLOWING BACK

摘要

PURPOSE: An apparatus for preventing flue gas of reheating furnace from flowing back is provided to maintain flue gas supplied into recuperator to a certain temperature or less by preventing the flue gas from flowing back through an air amount control valve during non-operation of a diluting fan for supplying air into the flue gas. CONSTITUTION: In an air supply apparatus for preventing thermal damage of a recuperator(104) connected to a reheating furnace(100) through passageway(106) to recover waste heat from flue gas generated from the reheating furnace, the apparatus(1) for preventing the flue gas of the reheating furnace from flowing back comprises second branch pipe(10) in which an air amount control valve(114) and a diluting fan(118) are arranged on first branch pipe(116) connected to a passageway between the reheating furnace and the recuperator, and which is connected to the first branch pipe between the diluting fan and the air amount control valve and connected to a pipeline(111) connected to burners(102) in the reheating furnace; a backflow preventing nozzle which is connected to an end part of the second branch pipe and arranged at the center of cross section of the first branch pipe, and on which a discharge port is formed so that air is supplied through the discharge port to prevent flue gas from flowing back in the first branch pipe through the air amount control valve; and a burner cooling fan(112) which is connected to the second branch pipe and the pipeline to supply air into the backflow preventing nozzle and supply air for cooling the burners in the reheating furnace.