Geodetic alignment methods for continuous casting machines (CCM )
This is an improved technology for position control of CCM equipment, based on high-accuracy on-line geodetic measurements. There suggested mathematical model of CCM technological axis, technology for optimal position of machine equipment in relation to the axis and software, which provides this technology.
In order to perform the works on this method the basic geodetic control network for CCM is created. The measurements are carried out by free station method with help of geodetic measurement complex “Vizir 3D”. The scheme of typical geodetic network is shown on the figure below.
Measurement of geodetic network and machine elements.
From the basic network points we perform the measurements of all CCM elements: framework axes, rolls, crystallizer …
Curving part can be described with enough accuracy by the second-order spline, i.e general equation of the curve in parts between the neighbouring rolls has the view:
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From joint solving of equation system, composed for all parts of semi-finished product trajectory, one calculates spline parameters and coordinates of points where the rolls touch theoretical curve of trajectory.
If some roll “k” does not touch project curve, then using trajectory equation one calculates the displacement of roll kk' to the normal direction of the curve. Thus, one will ensure the position of rolls to be in accordance with the specified trajectory of product in the zone of secondary cooling of CCM.
Mathematical CCM model
Ingot trajectory and roller position adjustment
The technology is tested on slab and sorted CCM of different producers: URALMASH, NMBP, SIEMENS, DANIELI
The output of bad quality products decreased on 30-60% after the optimal position alignment of CCM.
As a result of high automation the time of CCM alignment works reduced in 1,5 times.