Chemical Engineering June 2018 - 67

Concluding remarks
The examples shown in the extended
online-only version of this
article illustrate the point that a simplified
approach could be used to
evaluate the thermal performance
of boilers and their components,
such as superheater, economizer
fire tube or water tube evaporator
or fluid heaters. U or (UA) could be
obtained for the field data case and
extrapolated for another set of operating
conditions to determine the
thermal performance. It is important
that plant engineers obtain as much
tube geometry data and thermal
performance information from boiler
suppliers before ordering the boilers,
which will help them in their calculations
at a later date. Using these,
they can evaluate the performance
at off-design conditions.
Ref. 1 provides more information
on calculation procedures considerDependable
seals
start with DeWAL
Seals, gaskets and diaphragms can all leak, so DeWAL
Industries has developed a broad range of durable,
bondable PTFE and UHMW film and tape compositions
that create dependable seals despite abrasion, harsh
chemicals, high temperatures or irregular surfaces.
ing direct radiation, non-luminous
radiation and hence more accurate
procedures can be set up by plant
engineers for each boiler in their
plant, including steam generators.
They can use the results to monitor
the performance of various components
and large deviations from " predicted "
values can be taken up for
more detailed analysis.
Though these procedures may
not be as accurate as predicted by
a complete boiler performance program,
these calculations give an idea
how process engineers can use field
data to predict performance at any
other operating point. The calculations
should be backed up by proven
instrumentation, which will make
their performance predictions more
reliable. Knowledge of these procedures
will help plant engineers to become
more informed and challenge
boiler vendors in case they offer
" inadequate " or inaccurate process
thermal performance data while selling
their boilers. Computer code can
be developed by process engineers
to model each boiler performance in
their plant, which will help them to
assess whether or not changes in
the operating conditions are likely to
cause unfavorable conditions in their
boiler equipment.
n
Edited by Scott Jenkins
References
More than a dozen DeWAL PTFE and UHMW films and
tapes are designed specifically for gaskets, expansion
joints, valve seals and diaphragms.
1. Ganapathy, V., " Steam Generators and Waste Heat Boilers
for Process and Power Plant Engineers " , CRC press,
Florida, 2014.
2. Ganapathy, V., " Industrial Boilers and Heat Recovery
Steam Generators " , CRC Press, Florida, USA, 2003.
3. Ganapathy, V., Simplify Heat Recovery Steam Generator
Evaluation, Hydrocarbon Process., March 1990.
4. Ganapathy, V., Understanding Finned Heat Exchangers,
Chem. Eng., Sept 2013, pp. 62-65.
5. Ganapathy, V., Evaluate Extended Surface Exchangers
Carefully, Hydrocarbon Process., October 1990.
6. Ganapathy, V., Superheater Problems in Steam Generators,
Chem. Eng., February 2016, pp. 38-47.
Author
Viswanathan Ganapathy is an
international
boiler
Let DeWAL engineering
help you with your most
difficult challenges.
Quality of Product...First
Narragansett, RI 02882
www.dewal.com * usa1@dewal.com
800-366-8356 * 001-401-789-9736
from Chennai,
v_ganapathy@yahoo.com).
consultant
India (Email:
He
has over 45 years of experience
in the area of design and thermal
performance aspects of steam
generators, HRSGs and wasteheat
boilers. He has authored
over 250 boiler-related articles,
For details visit adlinks.chemengonline.com/70307-22
66
which have been published in several U.S., U.K. and
Indian publications. He has authored six books on boilers,
the most recent being, " Steam Generators and
Waste Heat Boilers for process and plant engineers, "
published in 2015 by CRC Press, Florida.
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
JUNE 2018
http://www.dewal.com http://adlinks.chemengonline.com/70307-22 http://WWW.CHEMENGONLINE.COM
Chemical Engineering June 2018

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