Determination of parameters of jet cooling of strip on a wide-strip hot rolling mill

When designing and setting up laminar strip cooling units, it is necessary to determine their thermophysical characteristics to calculate the thermal state of the strip after cooling. The paper presents a method for determining the main characteristics of the laminar cooling system impact on hot-rolled strip (jet pressure on the strip, vertical velocities in the collision zone, size of the active jet cooling zone, heat flux density in the collision zone). The paper presents the results of calculating the hydrodynamic and thermophysical characteristics of the cooling system using the example of collectors of a given design. It was determined that the final velocity of the jet fall on the axis weakly depends on the pressure in the system due to its low value and the large height of the collector above the strip. It was noted that at a pressure of 0.6 bar in the system, the heat flux density drops significantly at the boundary of the collision zone, which leads to deterioration of heat removal from the strip surface. The maximum heat flux density in the centers of the collision zones along the entire length of the laminar strip cooling system was 10-12 MW/m2.The study was supported by the Russian Science Foundation grant No. 23-29-00808, https://rscf.ru/project/23-29-00808. The work was also carried out with the financial support of the Ministry of Science and Higher Education of the Russian Federation (project No. FZRU-2023-0008).