External rings are not fixed to the kiln and have a slightly bigger radius than the kiln. Besides, they are not rotated – kiln rotates the rings. Because of the change of temperature inside the kiln, the kiln diameter may become bigger and smaller (at some places). If kiln becomes bigger than the ring, the ring can damage the kiln. So, the ring should be all the time bigger than the kiln, and therefore its rotation time should always be bigger than the kiln rotation time, that is we should always have some tire slip.

When the kiln or a ring makes full rotation, system gets a signal from the kiln trigger sensor or a ring sensor, so that the kiln and the ring rotation time is known and can be compared. We calculate tire slips of all rings and generate alarms if the calculated value is out of the predefined range. Alarm is also generated if we have no signal during the period of maximum kiln rotation time.

For more information see Tire slip monitoring topic.

Tire slip indicators are placed at the bottom of the measurement window. Each controlled ring has its own indicator. A tire slip indicator is a horizontal graphical stripe that changes its color depending on the ring condition. If tire slip falls into allowed range the bar is drawn in green, and the background is white. If tire slip value is outside the range, the bar becomes red, and the background orange.

Short tire slip trend

IRT KilnMonitor can display not only the current but also the recent rotation and tire slip values, several hours. To show them make sure that View | Rotation / Tire Slip Trend menu item is checked. Rotation and tire slip trends are displayed in the side view in the right part of the monitoring window:

If you click on the History link you will see tire slip trend in a separate window. Also you will be able to select large trend periods and load historical data. See Rotation / Tire slip history topic.

Trend period is 3 hours by default, can be configured in Linescano.ini:

[ROTATION]

recent_trend_time_span = last_3_hour