Walking beam furnace

Walking beam furnace, of end-in end-out type or side-in side-out type, is equipped with three stages of heating, i.e. first heating zone (preheating zone), second heating zone and soaking zone. Fuels may be heavy oil, coke oven gas, coal gas or natural gas.

Both the first and second heating zones are flat-topped and equipped with long blazing burners on two sides of their upper and lower heating sections for transverse heating. The soaking zone is also flat-topped, yet it is equipped with blazing burners on two sides of its lower heating section, and with flat flame burners on the top of its upper heating section.

Three heating zones are independently controlled in burning process. Its characteristics in heat supply modes are as follows:
1.Both of the first heating zone and the second heating zone are equipped with long blazing burners on two sides, which are arranged in a staggered manner.
2.The upper heating section of soaking zone is equipped with flat-flame blazing burners on the top to make steel billets heated evenly and to improve heating quality.

To satisfy the distribution requirements of 4.5m and 12m billets, there are six fixed water pipe beams, and six walking water pipe beams. All of the pipe beams are horizontal and supported by many single vertical pipes in “T” shapes. The furnace bottom water pipes all adopt natural circulation and evaporation cooling system.

The flue gases from burning are discharged from upper flue and lower flue on two sides of the furnace. Remaining heat energy in flue gases is absorbed by the heat exchanger to preheat air, then flue gases are used as tracing medium of heavy oil. Finally all flue gases are discharged through a very high chimney.

Acceptable steel billets conveyed by feeding roller table is positioned outside the furnace. According to process setting instructions, pusher travel distance and production rhythm, the steel billets are pushed in by the pusher at the end of the furnace. Steel billets in furnace are moved step by step when walking beam is working in cycle. Gradually, steel billets arrive at the exit, then they are lifted up, moved out by discharge machine. Finally they are transferred onto the discharging roller table, by which the heated billets are transported to rolling mills.

Steel billets are preheated, heated, soaked in the furnace in three zones: first heating zone, second heating zone and soaking zone. Steel billets meet the requirements of temperature and difference in temperature for subsequent rolling process.