2007-049 matthee quatenary crushers oil tanks

InfraMation 2007 Proceedings ITC 121A 2007-06-27

�� Hennie Matthee Diagnostic Engineering Thermographer ITC LEV III, South Africa, Sishen, Kumba Iron Ore Ltd. ��

Infrared is an excellent tool that is widely used for locating electrical problems. Too often we neglect the mechanical applications. Companies today are under tremendous pressure to reduce costs while maintaining production. As thermographers, we understand the value of IR systems for surveying electrical problems. However, we must realize it is also important to focus just as eagerly on mechanical systems as well. IR is such an effective tool in Condition monitoring programs. It is because this highly visual technology communicates information clearly and effectively. The source of thermal anomalies can be identified and repaired prior to equipment failure. This leads to a better predictive maintenance program and overall maintenance and operational savings costs. We as thermographers must remember that our surveys must include all factors of operation systems for us to be effective. This paper will demonstrate the need for this attention by using IR systems for Root Cause Failure Analysis to eliminate costly maintenance issues. ��

Routine inspection was done on Crushers with the infrared camera. The main objective of this IR inspection was to determine the accuracy of the Pt 100 by comparing counter shaft and oil Temperature readings with the LCD display and to report any anomalies. ��

LCD Display of crusher (Identification Nr.F752 G3200)

LCD display from PT 100 PT 100 not in position.

Trip Temperature (60°C)

33.6°C

52.3°C

35

40

45

50

AR01

24.8°C

46.6°C

25

30

35

40

45

AR01

Figure 1. Thermogram of PT 100 at Oil Tank. Figure 2. Thermagram of Crusher Counter shaft

AR 01 : Max Temperature 51.9 0C AR 01: Max Temperature 46.4 0C


It is second nature to a Thermographer to be curious, consequently looking at all possible effects of heat flow effects. For this reason I looked at the oil reservoirs. To my surprise the thermal image indicated Temperature differences at the bottom of some of the Oil reservoirs. The Question is “What are the images telling us?” Thanks to emissivity difference the root cause problem could be determined. By using IR the maintenance personnel improved the design of the reservoirs and the availability of the Crushers and reduced maintenance costs by extending oil life. OIL RESERVOIR Oil level BOTTOM OF RESERVOIR

18.0°C

33.9°C

20

25

30

SP01 SP02

LI01

LI02

21.2°C

44.4°C

25

30

35

40

LI01

LI02

Figure 2. Thermogram indicate residue at bottom on oil reservoir F752-G3100 and. F756-G3200. .

28.7°C

48.5°C

30

35

40

45

LI01

27.7°C

47.7°C

30

35

40

45

LI01

SP01 SP02

Figure 3. Thermogram on left test project of new oil filter on F752-G3200 system indicates no residue. F755-G3200 indicates residue at bottom af oil tank.

16.1°C

42.8°C

20

25

30

35

40LI01

SP01 SP02


To clarify the abnormalities indicated by the thermogram, oil samples where taken from the bottom of the reservoirs on all the reservoirs which indicated Temperature differences in the Infra Red images. The lowest suction point of the reservoir is located 100mm from the bottom of the reservoir. To insure that bottom samplings were taken the following sampling method was used. Filter Focus, a company specializing in protecting the integrity of oil by filtering oil to below 1 micron, removing water in solution down to 20 ppm, removing free sulphur and saving on current maintenance and repair costs make use of a one way valve mounted at the end of a 20 mm PVC electrical pipe to take bottom oil samples. See photo.

One way valve PVC Pipe Plunge

Figure 4. Photo of one way valve plunger mounted on a PVC electrical pipe.

The pipe was immerse into the oil. When the PVC pipe is at the base of the reservoir the plunger of the valve opens the valve and the oil flows to the inside of the pipe due to the oil level gravity. The pipe is removed from the reservoir and the oil is drained in to the sampling bottle. The oil samples were dispatch to Sishen mine Oil Lab to be analyzed. The Oil reports of the reservoirs confirm the build up at the bottom of the tanks. The build up indicate high iron (Fe), copper (Cu), Lead (Pb), Silica (Si) and Water (H2O) The oil analysis results are as follows: Unit Fe Cr H2O Si Pb PQ

755-3200 13321.0 3328.0 969.0 2103.0 16050.0 6784.00

756-3100 5882.0 1602.0 713.2 190.0 6150.0 4288.00

752-3200 258.0 442.0 1.0 6.0 268.0 120.00

756-3200 10459.0 1635.0 798.5 2095.0 5424.0 5749.00


Oil level Water Residue and. build up

Figure 5. Photo: Oil sample of F755 – G3200.

Oil level Residue and. build up

Figure 6. Photo: Oil sample of F756 – G3200.

The oil analysis reported indicated that the oil is very contaminated and that the Lab instruments filters blocked in the analysing process. What the IR image actually revealed is the residue and build up at the bottom of the tank. By positioning the suction point higher and not at the bottom of the tank will protect the oil pump from sucking in water and sludge. This sludge can not be effectively removed by the filtration system that is installed at the reservoir. The reservoir has no drain point to drain all the oil from the tank. This will contaminate the new oil when refilling. These findings were discussed with maintenance personnel to resolve the problem at hand and to establish the best solution for this problem. The following solutions were recommended by Diagnostic engineering to solve the problem. A. Clean the reservoir by hand. The reservoir can be cleaned by hand. This method is only possible during maintenance days. To do this the oil must be drained and the reservoir must be opened and be flushed out and cleaned by hand. This method can only be executed when major repair work is scheduled for a specific crusher. This method will be effective, however very time consuming.

B. Make use of the filtration system. It is recommended that we make use of the existing filtration system. The oil in the reservoir can be stirred, so that the residue at the bottom of the tank can be forced to move. The oil will flow through the filtration system and the filters will than clean the oil to the filter specifications. This will take time and the


cost of filters is expensive. Some of the contaminants might pass through the filter causing unnecessary wear. C. Redesign the oil reservoir Redesign the oil reservoir so that the sludge can be drained at any time. This design will also drain water from the tank. The design will still protect the pump and filters. No need to drain all the oil, reducing costs. D. Install new filter system on all oil reservoirs. Install the same filter system that is on 752-3200 on all the other reservoirs. The oil reports indicate that this new filter system is working. The IR images indicate that there are fewer residues at the bottom of the tank. Maintenance personnel decided to redesign the oil reservoir and to install the new oil filter system on all the reservoirs. NEW OIL RESERVOIR DESIGN.


Figure 7. Photo: Oil filtration systems.

19.4°C

39.9°C

20

25

30

35

19.0°C

34.4°C

20

25

30

Figure 8. Thermagram: oil reservoirs Eight months after modification. F751-G3200 and. F756 G3200

��

With regular IR inspections on the Oil Reservoirs the IR image will indicate the residue at the bottom of the tank and Maintenance personnel can be tasked to drain the sludge. �� ! ��"� ��

The author wishes to acknowledge the cooperation of Maintenance and Oil Lab personnel at Sishen Kumba Iron Ore Company for there assistance. We are also grateful for the support of Filter Focus South Africa personnel and H Rohloff (PTY) Ltd. Johannesburg South Africa who provided additional data and information for this paper. ��

Hennie is ITC certification Lev III Thermographer and has been using IR for 8 years. He was appointed at Sishen Mine on the 1 January 1986. He was trained as a Fitter and turner and qualified in August 1990. He achieved the following qualifications: National Higher Diploma N6 Mechanical and National Higher Diploma N6 Electrical at Kathu College. He has experience in the reconditioning of Hydraulic and Electrical equipment. He started at Diagnostic Engineering in 1994. He implemented and developed standards for Balancing at Sishen mine. He was part of the vibration section for 6 years where he was responsible for analyzing and reporting of all vibration readings. He started the Thermal Infrared program in 1999.

2007-049 matthee quatenary crushers oil tanks

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