In the high-speed continuous casting and rolling of aluminum plates, the accuracy of the head box aluminum liquid level control plays an important role in ensuring the quality of the cast-rolled aluminum plates.
In order to ensure continuous and stable aluminum plate casting, the amount of molten aluminum flowing into and out of the casting-rolling zone must be controlled in a balanced state, so that the aluminum melt in the front groove of the aluminum plate casting must be at a certain height. As the automation level of aluminum plate casting and rolling production lines is getting higher and higher, the speed of aluminum plate casting and rolling is getting faster and faster, and the width of the aluminum plate is getting wider and thinner. Therefore, higher requirements are put forward for the process level and automation of the aluminum plate casting and rolling production line, and higher requirements are put forward for the control accuracy of the liquid level of the front box.
When the aluminum liquid level of the head box is high, the pressure generated by the aluminum liquid is too large, resulting in the formation of edges on the outside of the aluminum plate, and the quality of the aluminum plate cannot be well guaranteed.
When the liquid level of the headbox is too low, the continuous supply of molten aluminum cannot be well ensured, and holes are prone to appear in the center of the cross-section of the aluminum strip or cracks appear on the surface, which affects the compactness of the aluminum strip crystals. It may cause the melt to condense in the casting nozzle, which cannot guarantee the continuity of production, and causes the outer surface of the aluminum plate to form fine holes. Therefore, it is necessary to ensure that the molten aluminum in the front box has a stable height, and control the molten aluminum flowing from the feed nozzle into the casting roll to have a relatively constant static pressure to ensure a sufficient and stable supply of the molten aluminum in the head box during the aluminum plate casting and rolling.
The high-precision and high-automation head box liquid level control system plays an important role in ensuring the continuity and stability of aluminum plate casting and rolling and the quality of aluminum plate. When the liquid level of the front box fluctuates, the liquid level will be adjusted steadily and quickly to reach a steady state.