Chemical Engineering January 2014 - 50

Engineering Practice
baseline temperature that is appropriate
for the application, after
which an acceptable bandwidth or
tolerance range is set - for example,
±10 degrees, although tighter
tolerances of ±1 or ±5 degrees
are possible.
When the trigger on a pistol-grip
scanning IRT is squeezed and the
device is moved slowly across the
target area, the device uses a combination
of sound (in the form of
slower versus faster beeping sounds)
and colored lights (for example, red
for above range, green for within
range, and blue for below range)
to alert the user to any location
where the temperature falls outside
of the user-specified threshold values
that define the setpoint range.
The IRT will also provide an absolute
temperature reading for that
particular spot.
While scanning IRTs do not produce
a thermal image, they do provide
a quick, easy, and relatively inexpensive
way for facility personnel
to assess specific mechanical assets
and identify those problem areas
that may require closer inspection.
A valuable investment
While individual thermal cameras
typically cost more than a thousand
dollars, they can be a strategic investment
- and will easily pay for
themselves over a short amount
of time if their use prevents a
catastrophic failure.
As noted, the use of remote, IRbased
thermal sensing to inspect,
troubleshoot, diagnose and rectify
problems with specific equipment
in realtime can help facility operators
to improve the efficiency and
effectiveness of both componentspecific
and plant-wide operation
and maintenance (Figure 5). Such
improvements provide a number of
opportunities for long-term savings
and payback. For instance:
* The costs associated with unplanned
downtime in industrial
facilities, such as manufacturing
plants and chemical process
facilities can be greatly reduced
when thermal imaging is used to
improve preventive and predictive
maintenance tasks
* Proactive troubleshooting
and diagnostic intervention
can help to decrease
the likelihood of expensive
or catastrophic equipment
failures - especially important
when considering
mission-critical assets
* The ability to plan and execute
more-strategic repairs
helps to cut material
and labor costs and extend
equipment life, thereby
helping to reduce both operating
and capital budgets
* Increased uptime allows
the facility to maximize
its throughput capacity, product
yields and profitability. The ability
to carry out strategic maintenance
activities helps to not
only save money, but improve
plant and personnel safety and
environmental performance
Figure 5. When operators are able to monitor
the thermal profile of equipment and systems
using a remote monitoring technique, they can
plan for the most appropriate and timely intervention
to address a deteriorating condition
nent's ideal state under normal
working conditions. Going forward,
any departure from normal temperatures
that appear in the thermal
images produced for the unit would
signify trouble spots that require
closer inspection.
Proper training and certification
Best practices
There are several ways to make
best use of thermal-imaging data.
Trending opportunities can be used
to the engineer's advantage. For
instance, the thermal signature
from a given component, such as a
particular pump that may be suspected
of having a problem, can be
compared to the thermal signature
of similar pumps in the facility. This
will help to evaluate its condition
relative to other equipment with
comparable operation.
In addition, the thermal images
generated for a given mechanical
asset (say, a particular motor),
can be strategically captured and
cataloged over time in specific intervals.
This record can provide
timely indications of deteriorating
conditions and help the operator to
make reasonable predictions about
the rate of future deterioration,
so that the required action - be
it maintenance, repair or replacement
- can be carried out, at the
appropriate time, in the most costeffective
manner.
When practical, it is a good idea
to carry out baseline thermal-imaging
inspections on new components,
to establish baseline or reference
images that represent the compo50
ChemiCal engineering www.Che.Com January 2014
are extremely beneficial when using
IRTs and thermal-imaging cameras.
While these devices are typically
simple to operate and provide
data and images that are easy to
interpret, both rely on sophisticated
technology. As such, to ensure the
most accurate results, users should
gain a good working knowledge of
the capabilities and limitations of
these tools through proper training
and certification. Without proper
training, the accuracy of the resulting
thermal data and images could
be compromised. Following vendorrecommended
operating guidelines
and proven industry best practices
is a must for data confidence.
Today, a variety of third-party
groups offer training and certification
in the proper use of thermalimaging
cameras, including the
American Society for Nondestructive
Testing (Columbus, Ohio; www.
asnt.org), the Academy of Infrared
Training (Bellingham, Wash.; www.
infraredtraining.net), the Infraspection
Institute (Burlington, N.J.;
www.infraspection.com), The Snell
Group (Barre, Vt.; www.thesnellgroup.com)
and others.
Choosing the right thermal imaging
camera for the environment has
an effect on the equipment's ability
http://www.asnt.org http://www.infraredtraining.net http://www.infraspection.com http://www.thesnell http://www.group.com http://www.Che.Com
Chemical Engineering January 2014

Table of Contents for the Digital Edition of Chemical Engineering January 2014
