Research CSP Copper Mold Flow And Heat Transfer Behavior

Thin slab continuous casting mold is the core equipment for the continuous casting process. Flow behavior and heat transfer behavior in mold have an important impact on the slab quality and copperplate life. So the research on the mold flow and copper heat transfer characteristics has important significance. The study in this paper created a1:1physical model according to similarity principle by taking Funnel type mold (main dimensions is length1580mm x width70mm x height1100mm, the largest mouth width is50mm and the height of funnel is850mm) as model sample. The effect of SEN structure, SEN submerged depth, casting speed and slab width on mold flow field was studied by using patical image velocity device and DJ800measuring system. And according to the equations of thermal conductivity and heat transfer, a model of heat transfer in mold wide copper was established. The heat flux and hot surface temperature was calculated and the effect of slab width and casting speed was discussed too.The results of water modeling research showed that the flow velocity in the nozzle exit increased with the casting speed’s improving, and that made the flow in mold and the impact depth became higher and the vortex core position down and the level fluctuation became more intense. The liquid level was more stability when the immersion depth became deeper. The SEN No.320had a lager outlet than SEN No.230so that it had a smaller outlet velocity, a wider main stream and a lighter impact depth. And as the result of above all, up recirculation zone developed completely, and the level fluctuation became more intense. With the increase of slab width, the outlet velocity of SEN and impact depth increased, and the maelstrom range was smaller, and the average surface wave height increased. When the slab width was1300mm, the fluctation of level was the lowest, and the liquid surface was smooth. By using SEN No.320, the best flow fluid and level fluctuation in mold could be got under the following conditions:slab width of1020mm,1100mm and1300mm with casting speed of5.0m/min and SEN immersion depth of90mm, slab width of1200mm and1250mm with casting speed of5.0m/min and SEN immersion depth of130mm, slab width of1550mm with casting speed of4.0m/min and SEN immersion depth of130mm. The results of heat transfer modeling showed:the part near the meniscus was the early stage of solidification, and the close contact of the mold copper plate and the initial solidification shell caused that the heat flux and temperature in this part was higher than in other places. Heat flux and temperature reduced rapidly with the increase of distance from500mm range away the mold top, and the remaining parts remained stable. Because of the weak flow and poor heat transfer of molten steel, the temperature of heat flux and hot surface near the SEN was lower than that in other parts in horizontal. In the middle of the mold, the temperature of heat flux and hot surface was uniform because of the good heat transfer performance which was caused by the narrow funnel reducing and the static pressure of the molten steel improving. Around the center of the mold outlet, the temperature of heat flux and hot surface was lower than that of other places because solidified shell was thicker and had larger amount of contraction. The uniformity of the heat flux distribution increased with the decrease of the casting speed.