DEVELOPMENT OF THE METHOD .1 Equipment and tools to be used

The inclinometer (see figure 5.1) is used to measure the inclination of a plane, that means, the absolute deviation of the vertical or horizontal plane.

The inclinometer is made up of a magnet holder (09), mounted to a bubble level holder (02), using a spike (08). Both carriers are manufactured in an aluminum body.

The Magnet holder supports two cylindrical magnets (10) and an adjustable top screw (13) with spherical tip.

The Bubble Level holder has a micrometric screw (05) and four bubble levels. A spring (11) supports the micrometric screw against the top screw’s spherical tip.

357948525.doc Page 38 of 111

Figure 5.1

The bigger bubble levels (03) and (04) are used to measure deviations of the vertical and horizontal plane inclination, respectively. The bubble levels are mounted in such a way that they can be regulated using the adjustment screws (06).

The small bubble levels (01) and (07) are directional levels used to control the position of the inclinometer in the plane.

When the inclinometer has to be used in rounded surfaces for example, trunnions of rollers, the Magnet Holder can be provided with a support bridge that can be attached to the magnet holder using a milano tail (12).

The distance between the micrometric screw (05) and the spike (08) is exactly 100 mm. Therefore, the millimeter graduation of the micrometric screw will correspond to the inclination percentage, so, 1 mm is equivalent to 1% of inclination.

In the micrometric screw 0.002 mm, its equivalent to an inclination of 0.002%, or 0.02 mm, by 1000 mm

5.3.1.1 Control of the adjustment

The inclinometer is provided by the supplier already fixed, however, the adjustment must be controlled before using the inclinometer. The adjustment must be verified always if the device has been used previously.

The adjustment can be considered as correct when the inclinometer is in horizontal plane, the bubble is centered and the micrometric screw is placed in 10.000 mm

The adjustment demands a high degree of exactitude and can be difficult if a precise angular plane is missing, for example from a machine tool or a mark end.

When it is only necessary to measure in vertical plane, for example in ends of support sheaves axis definitively mounted, that is our case, it will be more advisable to perform an adjustment in the top screw with sphere (13) until assure that the bubble level (03) is in perpendicular position to the magnets support face, when the micrometric screw is adjusted to 10.000 mm

5.3.2 Frequency

The measurement of the rollers inclination must be made annually.

5.3.3 Procedure, calculation methods and results

5.3.3.1 Measurements of rolls inclination (support sheaves)

The device must be handled carefully. For example, the arm does not have to hit with excessive force the edge, such a blow can modify the adjustment of the inclinometer.

Hold the inclinometer in the inclined plane using magnets (10).

Control with the directional levels to have the inclinometer parallel to the inclination direction. In measurements due in trunnions, the inclinometer must be on vertical position upon the axis line in the same axis.

Turn now the micrometric screw until the bubble of the chosen level is centered. Read the value h in the micrometric screw and calculate the inclination percentage V as following:

V = 10 - h %

The sign depends on the inclination sense and the inclinometer position, nevertheless, the sign has not any meaning considering that the inclination is indicated in percents and the inclination sense has been established.

- Measure in both trunnions. In unloaded support sheaves the measurements must be identical, that is to say that the deviation degree of 10,000 must be the same one if the measurement has been performed correctly. In support sheave under load a difference of a few thousandths of percentage between the two measurements may appear.

357948525.doc Page 40 of 111

Control, at the same time, if the axis ends are perpendicular to the trunnions. This can be important during later measurements that only can be made in the axis ends

When measuring the inclination of definitively mounted support sheaves, normally the inclinometer is placed over the turned axis ends of the support sheaves and it is measured, at the exit end of axis as in the entrance end, an average value is then calculated.

It is necessary to be assured against inaccuracies as a result of irregularities in the mechanized of the axis ends measuring in both sides of the axis center and use the average value of the two measurements. See the figure number. 5.2.

The inclinometer must be placed in such a way that the line in the magnet holder flank (09) is located exactly upon the horizontal line of axis of the same axis, as shown in figure. 5.3.

If the inclination in a support sheave under load is measured, according to the described method, an insignificant divergence between the measurements of both axis ends can be appraised (as previously mentioned), as a consequence of the bent in one of the support sheaves. This is not an anomaly symptom and applying the average measurements when performing the inclination estimate is compensated by this divergence.

Figure 5.2

Figure 5.3 5.3.3.2 Operation Procedure.

Carefully clean the axis ends before perform the measurements.

Measure firstly the superior axis end, next to the entrance of the furnace. Measure both sides of the axis center and compute the average value R i . See figure 5.3.

Next, measure next in the end of inferior axis, nearest to the output, and compute the average value R 0 based on the measurements conducted here.

The numerical value of the two measurements will be in the proximities of the value for the horizontal plane, as shown in figure 5.3 and the inclination of the support sheave could consequently be established as:

R i - R o

R m = --- % 2

Once the two measures R i and R 0 have been taken, it will be necessary to establish their deviation of 10,000, that means the inclination percentage for both axis ends

Being an unloaded sheave of support, both percentages must be identical, and in a support sheave under load the reciprocal difference does not have to surpass 0,02%. In case of having a superior divergence it means that the measurements have not been taken correctly and, therefore, will have to be repeated.

5.3.4 Interpretation of results

The difference between the inclination percentage in the entrance and exit extremes of the support sheave must surpass the 0.02%. As well as the maximum deviation of parallelism between support sheaves (rollers) and the tread hoops (rims) must be 0.02%.

In all cases the indications of maximum inclinations the mentioned in the position plane corresponding to furnace must be followed.

357948525.doc Page 42 of 111

Ro Ri

5%

4 32

8 9

6 7 1112 13 14

In some cases the end faces of the rolls cannot be used as a base for the inclination measurement, as in the case of furnaces operating in good condition during a long period. The measurement of the inclination can be performed, doing double measurements in each end of the axis, while the support sheave is turned 90º between the two double measurements.

In the case that this operation does not offer a sufficiently reliable result either, it will be precise to disassemble the superior part of the rowlock, in order to be able to perform a control measurement on the trunnions.