OPTIMIZATION OF WORKING ROLL COOLING IN HOT ROLLING

OPTIMIZATION OF WORKING ROLL COOLING IN HOT ROLLING

Summary research report

The optimal cooling of rolls should be designed with respect to two aspects. The first is the wearing of a roll where high temperature decreases the durability of the surface layer. The second aspect is thermal deformation of a roll. There are many factors which can influence the efficiency of the nozzle cooling system: type of nozzle, geometrical configuration (nozzle pitch, distance from the roll, orientation, number of manifolds), coolant pressure and temperature. Cooling intensity is mostly specified through the heat transfer coefficient or heat flux distribution. Coolant flow on the rotating roll surface makes the problem complex. Surface temperature of the cylinder plays an important role in the heat transfer mechanism, especially for higher temperatures where boiling must be considered. No analytical or numerical solution of heat transfer and fluid flow for this case is known. The task can be successfully solved experimentally. An experimental bench and methodology of realistic boundary conditions determination was developed in the Heat Transfer and Fluid Flow Laboratory. The optimized cooling system was applied on a hot flat rolling mill in voestalpine Stahl GmbH.

The optimal cooling of rolls should be designed with respect to two aspects. The first is the wearing of a roll where high temperature decreases the durability of the surface layer. The second aspect is thermal deformation of a roll. There are many factors which can influence the efficiency of the nozzle cooling system: type of nozzle, geometrical configuration (nozzle pitch, distance from the roll, orientation, number of manifolds), coolant pressure and temperature. Cooling intensity is mostly specified through the heat transfer coefficient or heat flux distribution. Coolant flow on the rotating roll surface makes the problem complex. Surface temperature of the cylinder plays an important role in the heat transfer mechanism, especially for higher temperatures where boiling must be considered. No analytical or numerical solution of heat transfer and fluid flow for this case is known. The task can be successfully solved experimentally. An experimental bench and methodology of realistic boundary conditions determination was developed in the Heat Transfer and Fluid Flow Laboratory. The optimized cooling system was applied on a hot flat rolling mill in voestalpine Stahl GmbH.

roll cooling, rolling mill, heat transfer, hot rolling, nozzle

roll cooling, rolling mill, heat transfer, hot rolling, nozzle

KOTRBÁČEK, P.; HORSKÝ, J.; KVAPIL, J.; ASTROUSKI, I.; BULEJKO, P.

2014

28.03.2013

1

20

20

http://hdl.handle.net/