The purpose of this system is to monitor any significant rise of temperature in the Uni-Mill housing. The effect of heat generation on material during milling can result in damaged tooling, ruined batches and, in severe cases, can even cause an explosion. Heat is predominately generated within the gearbox and the screen located in the machine housing and the temperature of these parts increases as they run for long periods of time.
Temperature Probe
A temperature probe is fitted through the wall of the impeller housing which contacts the back surface of the mill screen providing constant indication of the screen temperature during milling. Alternatively, the probe can be positioned against the gearbox to measure bearing temperature. The PT100 temperature probe can be easily removed from the mill-housing for cleaning.
The probe is connected to a temperature monitor located in the mill control panel. The temperature monitor has two set points (high and low) but in most cases only the high set point is used. If the temperature inside the Uni-Mill exceeds the set point (typically 50°C but can be adjusted), the Uni-Mill will shut down and an alarm or visual indication will show on the control panel or external control system.
Alerting the Operator
There are two main options for alerting the operator that the mill has reached (or is about to reach) the high set point. Commonly, a temperature display screen is used which provides an exact reading of the temperature that the probe is measuring. The operator can see exactly what temperature the mill is running at and can see how changing any variables affects this.
A warning light / beacon or audio alarm can be use in addition to, or instead of, the display screen. In a busy processing environment, a more noticeable indication that the mill has reached the high set point may be required and these alarm types provide this.
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