| Nozzle is the key component in the roll cooling system. Choosing and arranging the nozzles appropriately is very important, that can make the cooling liquid spray on the roll uniformly and take away the generated heat as much as possible. The flat fan nozzle is now widely used in roll cooling system. The jet performance of flat fan nozzle is scientifically studied in three ways in this paper:theoretical analysis, finite element simulation and experiment study.Using jet theories, the mathematical models that can describe the spray area, the average velocity and the flow distribution of flat fan nozzle are established. The influences of the hemisphere radius, the milling groove depth, the milling cutter angle of flat fan nozzle on the jet performance were discussed by use of this mathematical model. The flow inside and outside the flat fan nozzle is simulated by Fluent software, and the influences of the structure parameters of flat fan nozzle on its jet performance were analysed by the simulation results. A test rig which for the flat fan nozzle is developed, by which the GYQ 1981 B1 nozzle is tested and the influences of the hemisphere radius, the milling groove depth, the milling cutter angle of flat fan nozzle on its jet performance are obtained. The 3-D graphs of the jet shape and the flow distribution of different flat fan nozzles on different distance sections are protracted. The elliptical shape and the flow distribution of the fluid sprayed on the roller surface is calculated by mathematical methods. A criterion that can evaluate the cooling uniformity on the roller surface is built up, and the arrangement of the flat fan nozzles is optimized. Taking the GYQ 2125 B1 nozzle as an example, the optimization is made with different deflection angle and different separation distance and find that the most uniform flow distribution is obtained when the nozzles are installed with 1°～6°deflection angle and 10mm separation distance. |
PDF Full Text Request