Annealing furnace is the core equipment of production line, including seal chamber, flame heating section, reduction section, cooling section, balance section, chamber for thermal tensioning roller. Its main function is heating, insulation, cooling and temperature uniformity of the strip steel according to the grade requirements of product and the corresponding annealing and heat treatment curve, to complete the recrystallization annealing of the strip steel and to make the strip reach the required temperature before entering the zinc pot. Through chamber for thermal tensioning roller (furnace nozzle) the strip goes into the zinc pot.

Low nitrogen and oxygen compound burner is adopted to heat the open fire section of annealing furnace, and the flue gas preheats the combustion air in a concentrated way, so as to save fuel. The combustion mode of the burner can be controlled to adjust the atmosphere without oxidation in the furnace, ensure the strip steel in the range without oxidation, and clean the strip steel at high temperature.

The annealing furnace is equipped with a four-stage waste heat utilization system, which effectively saves energy. The first stage is PHF combustion exhaust directly preheating the steel strip to 400~450. The second stage is to preheat combustion air to 400~450 by using combustion waste gas. The third stage is to preheat the air to 90~110 for drying of pretreatment, water quenching and other section; The fourth stage is used for circulating heating of alkali liquor and washing water in the cleaning section.

The reducing section of annealing furnace adopts fiber blanket with good insulation performance, while the heating section adopts open flame burner, ensuring the average energy consumption of 18-20 cubic of gas for 1 ton of product (low gas calorific value: 8430Kcal/Nm3), and the emission index conforms to the national standard.