spm hd case study

SPM Instrument BV I PO Box 86 I NL-5150 AB Drunen I Netherlands Tel +31 (0)416 373176 I Fax +31 (0)416 373279 I [email protected] I www.spminstrument.nl ©  SPM 2012-02 CS_005B

CASE STUDY

SPM®HD Case Study “Guide Roller” Sieve Guide Roller 1DRG-WM56 Drive End Side

Paper Mill PM1, Smurfit Kappa Roermond, The Netherlands

by

Steef Peters,

SPM Instrument BV, The Netherlands

February 2012

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Contents

1 Introduct ion ........................................................................................................................... 3 2 Conclusion and summary .................................................................................................... 4 3 Appl icat ion descr ipt ion ........................................................................................................ 5 4 System setup ........................................................................................................................ 6 5 Case descr ipt ion ................................................................................................................... 8

6 Appendix (p ictures) ............................................................................................................ 13

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1 Introduction

This case study describes an online measurement taken from a “Guide Roller” cylinder at the paper mill Smurfit Kappa Roermond, using the SPM®HD method. The Guide Rollers in Paper mill 1 are divided into three sections: Top Guide Rollers, Middle Guide Rollers and Basement Guide Rollers. This particular guide roller belongs to the middle section and is situated at the end of the paper mill. At the moment all guide rollers (top, middle and basement) are monitored with Intellinova SPM®HD, all drive end side. At the moment the drive end side of paper mill no.1 is completely equipped with Intellinova SPM®HD; e.g. drying cylinders, guide rollers (top, middle and basement), bel-bond (re-versed screen), screen group, press group and glue press. Some cylinders are also Intellinova SPM®HD equipped at the non drive end side. In due time, the entire paper mill no.1 should be equipped with Intellinova SPM®HD (all non drive end sides). This guide roller is chosen for a case story because of the perfect example concerning measure-ments rising and dropping several times due to damage which is rolling out and the inner race which sometimes skids over the shaft.

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SPM Instrument BV I PO Box 86 I NL-5150 AB Drunen I Netherlands Tel +31 (0)416 373176 I Fax +31 (0)416 373279 I [email protected] I www.spminstrument.nl

2 Conclusion and summary

On March 5, 2010 SPM HD was introduced on this guide roller. Starting from this date, a steady trend graph HDm was created with a very small increase until Oct 24, 2011. Hereafter subsequently an increase and decrease appears, three times in succession. During the first increase, the SPM spectrum shows a clear inner race bearing defect with (increas-ing) harmonics and sidebands on 1 x RPM. Next the decrease of the signal sets in. During this de-crease, the inner race bearing defect is replaced by an outer race bearing defect. Plausible causes for the inner race defect to disappear are; damage which is rolling out and/or the inner race skid-ding over the shaft (See picture 2, wear tracks from the shaft to the inner race). The second increase shows again a clear inner race defect with harmonics and sidebands on 1 x RPM. After the second increase, the trend decreases again for a very short period, to subsequently increase for the last time, with a worsened indication of the inner race bearing defect. On Nov 22, 2011 the particular paper mill had a planned stop for general maintenance. Because of the clear damage indication, the bearing was disassembled and replaced by a new bearing. At this point the HDm value is 34.8 HDn and HDc is 18.5 HDn. In combination with the damage on the bearing inner race, this can be seen as a perfect pre-warning example (clear visible damage on the outer race and already declining damage on the inner race). With regard to the skidding inner race on the shaft, the dimensions of the shaft were checked and just out of tolerance. For the new bear-ing inner race, the mechanics cleaned and degreased the shaft and glued it to the shaft with Loc-tite. When comparing the HDm level reached and the damage seen on the bearing inner race, it is likely that the bearing would have survived another six weeks until the next planned stop for this paper mill. However, the no-risk policy of Smurfit Kappa demanded replacement of the bearing. A good result for BPFI indication was taken out of the SPM spectrum; harmonics and sidebands nicely visible. A better result was taken from the Colored Spectrum Overview. Nicely visible is the combination of inner and outer race damage. As an end result of the measurements taken by SPM HD, a very good example of damage rolling out and / or skidding of the inner race over the shaft (increasing / decreasing trend graph). Not to forget of course is that NO unplanned downtime of the paper mill has occurred; even a guide roller which crashes can lead to unwanted paper rupture.

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3 Application description

A guide roller is and acts just as the name describes; to guide the felt / paper. There are three kinds of guide rollers:

• Fixed guide roller (for guidance only) • Tension guide roller (for tensioning and guidance of the felt) • Adjustable guide roller (one side is automatically adjustable for adjusting the latitude posi-

tion of the felt). The WM56 is about a fixed guide roller and is located in the 3rd drying section of Paper mill 1 (see Figure 1, red arrow for WM56)

Glue press

2nd drying section

Fig. 1 Overview 3rd drying section, Paper mill 1, red arrow WM56.

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4 System setup

Figure 2 shows the position of the SPM transducer; in this case a 40.000 with TMU, high tempera-ture due to surroundings. Intellinova: System Unit INS10, Commander Unit INC40 Settings used in Condmaster Nova 2010.007:

- Measuring Time Same as FFT measurement - Short / long term memory Time signal and FFT - Upper frequency 100 Orders - Lines in spectrum 800 Lines - Symptom enhancement factor 5 - No. of revolutions 67.2 - Measuring interval 1 hour Filtering of results (LinX) - Value HDm - Accepted value All - Min variation for storing 3 - Forced storing interval 10

Fig. 2 Position of SPM transducer.

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Alarm Limits for HDm only - Moving average - Number of averages 10 - Upper alarm limit 26 (Yellow), 35 (Red) Bearing type SKF 22217E (Mounted) - BPO 9.037 - BPI 11.963 - 2*BS 6.962 - FT 0.430 Bearing type FAG 22217EAS (Possible mounted) -BPO 7.615 -BPI 10.385 -2*BS 6.284 -FT 0.423 It is possible that guide rollers are still equipped with a FAG bearing which obtains different bearing defect frequencies than the same type SKF bearing. Nowadays, Smurfit Kappa only uses SKF bearings, but stray FAG bearings still mounted in the pa-per mill are possible. In this case an SKF bearing was mounted.

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5 Case description

Starting from Oct 25, 2011 (green arrow), HDm level starts to increase in combination with an in-creasing delta shown in the Level Graph. Reaching the top of the first increase, a clear indication of bearing defect inner race is seen in the SPM spectrum (see Fig.4, SPM spectrum 28-10-2011).

Fig.4

Fig.5

Fig.6

Fig. 3 Level Graph HDm & Trend Graph HDm, from August 2011 – January 2012.

Fig. 4 SPM spectrum 28-10-2011

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After the first increase / decrease, a period occurs where the trend is relatively stable, starting from the yellow arrow (03-11-2011) until the blue arrow (10-11-2011). During this period, the bearing inner race defect almost disappears and a reasonable bearing outer race defect appears (see Fig.5, SPM spectrum 03-11-2011).

Time signal corresponding with the above shown SPM spectrum, Fig.5. BPFO of 9.037 is visible during 1 revolution in the time signal; approximately 9 peaks. Due to broad damage on the outer race (harmonics), the signal is “stretching out” at every peak.


Fig. 6 SPM Time Signal 03-11-2011, corresponding to the SPM spectrum in Fig.5.

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Starting from the blue arrow until the red arrow (planned machine stop), there occurs an increase, decrease and again an increase in the trend graph. The bearing defect outer race disappears while the bearing defect inner race emerges again. After the increase the bearing defect inner race only deteriorates, until the planned machine stop on 22-11-2011. In Fig.7 the spectrum is shown just before machine stop 21-11-2011.

The values of BPFI and BPFIM [HDesv]: BPFI BPFIM 28-10-2011 455 973 03-11-2011 132 387 21-11-2011 376 953 Noticeable is the drop in values [HDesv] when the trend graph decreases and the bearing defect inner race almost disappears.


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The Colored Spectrum Overview (Fig. 8) corresponds with the Level- and Trend Graph HDm from figure 3 on page 8. Starting from the green arrow in Fig. 3, a clear development of bearing inner race defect including harmonics and modulation (BPFIM) can be seen. From yellow arrow to blue arrow, there is an indi-cation of bearing outer race defect (BPFO). From blue arrow to red arrow, the bearing inner race defect is returning, the values are rising and the amount of sidebands is building up (see also Fig. 9 and 10, Enlarged Colored Spectrum Over-view). Yellow Comment Block is indication of planned paper mill stop and replacement of the bearing. After replacement of the bearing, only BPFO is visible with some harmonics and HDm values at about 18HDn. In this case it is a normal pattern for a good running bearing.

Fig. 8 Colored Spectrum Overview

BPFO BPFI

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Fig. 10 Enlarged Colored Spectrum Overview (page view from Fig.9)

BPFO

Fig. 9 Enlarged Colored Spectrum Overview

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6 Appendix (pictures)

Picture 1 Bearing outer race; clear damage in the load zone.

Picture 1, Bearing outer race.

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Picture 2 Bearing inner race; damage (wear tracks) due to skidding on the shaft (red arrows) + in the oval, the “normal” inner race damage.

Picture 3 Bearing inner race; damage on the inner race.

Picture 2, Bearing inner race

Picture 3, Bearing inner race

spm hd case study

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