Patent ID: 8277720

Claim:
A device for heating a metal material ( 2 ) with a longitudinal direction ( 1 a ) and a transverse direction ( 1 b ) perpendicular to the longitudinal direction ( 1 a ), comprising: an elongated direct flame impingement (DFI) burner device ( 3 ) arranged to be driven with gaseous oxidant and gaseous fuel, where the metal material ( 2 ) and the burner device ( 3 ) are arranged to be displaceable relative to one another in the longitudinal direction ( 1 a ); and a supply device ( 4 ) for fuel and a supply device ( 5 ) for oxidant, wherein the burner device ( 3 ) comprises an elongated, tubular fuel vessel ( 10 ) and an elongated, tubular oxidant vessel ( 20 ), the respective vessels ( 10 , 20 ) are arranged in parallel to each other and to the surface of the metal material ( 2 ), they each have one or more openings ( 11 , 21 ) arranged along the vessel ( 10 , 20 ) through which the fuel and oxidant respectively are arranged to flow out and then converge in an ignition zone (L) outside the respective vessels ( 10 , 20 ) where a flame is generated, the respective supply devices ( 4 , 5 ) are arranged, by means of a regulator ( 6 ), to keep the pressure in each respective vessel ( 10 , 20 ) constant throughout the vessel ( 10 , 20 ) in question during operation, and each respective vessel ( 10 , 20 ) comprises a piston ( 12 , 14 , 22 , 24 ) which is arranged to be able to be displaced in the longitudinal direction of the vessel ( 10 , 20 ) and hence to prevent fuel and oxidant respectively from flowing out through openings along the longitudinal section, which openings the piston ( 12 , 14 , 22 , 24 ) temporarily screens from admission of fuel and oxidant, so that the propagation of the flame in the longitudinal direction of the vessels ( 10 , 20 ) thereby can be regulated.