Device for limiting the exhausting of combustion flue gases at the inlet of a furnace for reheating steel products

Abstract

The invention relates to a device for limiting the combustion fume exhaust towards the outside of a continuous furnace, especially a tunnel furnace, for reheating iron and steel products, especially slabs, at the opening located at the entrance of the furnace. The first row of burners consists of at least two burners ( 2 a, 2 c ) arranged at the same distance (D) from the entrance of the furnace and close thereto, and the burners of the first row of burners are inclined mainly from an angle A towards the discharge area of the furnace.

1 . A device for limiting the exhausting of combustion flue gases to the outside of a continuous furnace for reheating steel products, particularly steel slabs, especially a tunnel furnace, at the opening located at the inlet of the furnace, wherein the first row of burners is made up of at least one pair of burners ( 2   a,    2   c ), each burner is placed above the products ( 5 ) to be reheated, facing each other at the same distance (D) from the inlet of the furnace and close to the inlet of the furnace, and in that the burners ( 2   a,    2   c ) of the first row of burners are angled mainly at an angle A toward the outlet of the furnace relative to the transverse plane perpendicular to the longitudinal axis of the furnace. 
   
   
       2 . The device as claimed in  claim 1 , wherein the distance (D) from the first row of burners to the inlet of the furnace is between 0.3 and 1.5 m. 
   
   
       3 . The device as claimed in  claim 1 , wherein the distance (D) from the first row of burners to the inlet of the furnace is less than the internal half-width of the furnace. 
   
   
       4 . The device as claimed in  claim 1 , wherein the angle A at which the burners of the first row of burners is angled toward the outlet of the furnace is between 10 and 45 degrees. 
   
   
       5 . The device as claimed in  claim 4 , wherein the angle A at which the burners of the first row of burners is angled toward the outlet of the furnace is 30 degrees. 
   
   
       6 . The device as claimed in  claim 1 , wherein the first row of burners comprises at least four burners ( 2   a,    2   b,    2   c,    2   d ) distributed in two pairs of two burners, one ( 2   a,    2   c ) placed above the products to be reheated with each burner at one and the same height (H 1 ), and the second below the products to be reheated with each burner at one and the same height (H 2 ). 
   
   
       7 . The device as claimed in  claim 1 , wherein the burners ( 2   a,    2   b,    2   c,    2   d ) of the first row of burners operate under fixed conditions and at a nominal power, the operating power of these burners thus being kept constant, whereas the operating power of the other burners ( 2 ) varies according to the calorific requirement of the furnace.