Inspection in accordance with the statutory standard
To guarantee the continuity of production radical measures have been taken. A stoppage of one of the two paper making machines means a loss of tens of thousands of Euros per hour.
A thorough preventive maintenance programme tracks down potential sources of faults in good time. An infrared camera plays a leading part in this. “Initially we had our electrical engineering installation inspected periodically by an external thermographic consultancy bureau”, explains Theo Janssen, Group Head of Electrical Engineering and Instrumentation. “The infrared images that we received from the bureau convinced us of the value and of the possibilities of using thermography. The need to increase the frequency of the measurements and in particular to extend their scope soon led us to buy our own infrared camera. The ThermaCAM™ from FLIR Systems fits in perfectly with our requirements”.
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The ThermaCAM PM 695 is the first camera in the world to produce an infrared and a visual image at the same time.
Inspection of high voltage installations during operation
Parenco’s in-house energy generation plant supplies a
maximum power of 58 MW. The installed power amounts to approx. 132 MW.
An electricity company sub-station provides any additional power
required. “The high voltage components are of course extremely critical
for the business process”, explains electrical engineer Mark Kobus.
“Defective contact resistances in a high voltage cable for example can
cause serious damage. Thanks to the ThermaCAM we can now examine all the
installations for suspected hot spots during full operation. We draw up
a report on this including the infrared recording and send it to the
responsible department. They determine whether the part must be replaced
immediately or whether the replacement can wait until the next planned
stop for regular maintenance”.
The invisible becomes visible
“A world opens up to you when you look at the
installations with the infrared camera”, says Barney Soerink. “You see
things that remain hidden to the human eye. The enthusiasm of the two
also inspires other departments within the paper factory to have
thermographic measurements carried out. The camera is now also giving
service in tracking uneven loads on motors and other
(electro-)mechanical components; the heat distribution of the
brush-holders in motors ruthlessly displays the load distribution.
“After the first measurement we discovered another 17 motors with
increased contact resistances”, announces Mark Kobus. Temporary repair
was able to prevent worse happening.
Moisture profile of paper
Making newsprint, in addition to the main raw
materials of wastepaper and wood, also requires a lot of water. During
the production process the moisture content is reduced by drying and
pressing from 1% consistency in the head box to a moisture content of 8%
on the rewinder. Many parameters affect the drying process. An
up-to-date moisture profile thus tells us a lot about the quality of the
drying (and hence about the quality of the end product). The infrared
camera gives a good picture of the moisture distribution in the paper
web, shooting past at a speed of approx. 1600 metres per minute.
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Inspection of the moisture distribution in the paper web shooting past at a speed of approx. 1600 metres perminute.
Rapid return on investement
Most of the heat for drying the paper is added in the form of steam. The Renkum factory has an extensive network of steam piping. Very often the infrared camera has been able to detect a steam leak via striking temperature differences. “That is of course not critical to the business, but does mean a waste of energy”, confirms trouble-shooter Barney Soerink with satisfaction. “The ThermaCAM has also amply paid for itself even without this energy saving”. A number of unplanned outages have been prevented by the measurements. This has in particular contributed to a very short pay-back time for the ThermaCAM.
Right image interpretation by training
Mark Kobus together with colleague Barney Soerink
followed the certified training as thermographers at the Infrared
Training Center (ITC), the training institute for FLIR Systems. Both men
think the training is a must for any (budding) thermographer. “You
learn to interpret infrared images, as well as what environmental
factors can affect the measurements. The cameras offer every facility to
eliminate false information, but you have to learn to recognise this
possible interference. At the ITC they have information on every
practical situation”.
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Both thermographers have their eye on the latest model ThermaCAM, the PM 695. This camera has an integrated video camera so it can take an ordinary photograph at the same time as the infrared recording. A separate digital camera thus becomes superfluous. The PM 695 also has facilities for recording all sorts of information on the measured object during the measurements in the field. The recording can even be accompanied by the spoken word. These facilities considerably simplify the reporting; virtually all the required information is after all recorded by infrared and visible photograph.
