Pool-level sensing probe and automatic level control for twin-belt

Abstract

In continuous metal-casting machines utilizing one or more thin flexible belts as mold surfaces, a suitably placed thermal sensing probe which contacts the reverse side of a casting belt results in enhanced control of molten-metal pool levels, in contrast to the earlier systems where a series of separately monitored probes were disposed serially against the belt from upstream to downstream, each of which registered a separately monitored 'yes' or 'no' signal. In accordance with the present invention, an intermediate temperature is selected as the control point, at one location in the mold. If the pool of molten metal rises above the optimum level, the sensing probe will register a correspondingly increased temperature. If the pool falls below optimum, the probe will register a cooler temperature. The resulting electrical signals are processed by an electronic circuit. The result may be displayed for manual control of metal feed or machine speed, or a resulting control signal may be employed to control automatically the flow of molten metal into the mold cavity or, alternatively, to control the speed of the casting belts which convey metal through the casting machine. Multiple sensing probes disposed serially along the direction of motion of the moving mold afford a greater physical length of effectiveness of pool-level control when they are wired in series or otherwise related so that their signals are summed up to result in only one combined single-channel signal to be monitored or to be used for automatic control.