Hydrocarbon Processing - April 2022 - 40

Heat Transfer
vertically through half of the thickness
and then further drilled horizontally to
vent or drain out to the atmosphere, as
shown in FIG. 3; and a similar arrangement
can be applied to drain nozzle.
Lack of baffle support (to the tubebundle)
due to a flanged and flued
expansion joint. A flanged and flued
expansion joint is typically provided with
an internal sleeve to assist the shell-side
flow; however, a sleeve may not be necessary
in a vertical exchanger. An internal
sleeve is necessary for process reasons to
minimize the frictional losses or pressure
drop and ensure smooth shell-side flow.
For horizontal exchangers with a
LWN flange
Hole for vent
Tubesheet
flanged and flued joint, an internal sleeve
is purposely required for mechanical reasons
and to support the baffle (as well as
prevent the tube bundle from sagging)
because a possibility exists that one or
two baffles will most likely be located
along the length of the expansion joint
where a portion of cylindrical shell will
be unavailable due to placement of the
expansion joint. Without a sleeve or liner,
a baffle (or baffles) that falls within the
ends of the flanged and flued joint will
lack shell support. The sleeve acts as the
shell and provides mechanical support to
the tube bundle to resist gravity.
Without the sleeve, maldistribution
of shell-side flow, resonant vibrations or
sagging of the tube bundle-or all these
combined-can ultimately cause the exchanger
to fail. The authors encountered
some horizontal exchangers with flanged
and flued expansion joints in which internal
sleeves were not provided.
Consider FIG. 4C: a sleeve is still reShell
FIG.
3. Vent and/or drain nozzle arrangement
for vertical heat exchanger.
quired where baffles are clearing the expansion
joint, which is not designed to
share part of the bundle weight (acting
as a point load). For the situation shown
in FIG. 4B, a sleeve is necessary to provide
baffle support. Providing a sleeve will
also give more flexibility with respect to
baffle location. FIG. 4A illustrates an acceptable
construction.
Design review experience is acquired
by continuous practice and improvement,
and the authors believe that the feedback
of uncommon lessons is helpful.
Part 2 of this article will appear in the
May issue.
LITERATURE CITED
1
American Society of Mechanical Engineers
(ASME) Boiler and Pressure Vessel Code, Section
VIII, " Rules for construction of pressure vessels-
Division 1, " New York, New York, July 2019.
2
" Standards of the Tubular Exchangers
Manufacturer's Association Inc. (TEMA), 10th
Ed., 2019.
3
American Petroleum Institute (API) Standard
660, " Shell-and-tube heat exchangers, " 9th Ed.,
Washington, D.C., May 2020.
Complete literature cited available online at
www.HydrocarbonProcessing.com.
KUNTAK DARU is a Pressure Vessel
Engineer with Air Products and
Chemicals Inc. Mr. Daru works
in the mechanical equipment
division of Air Products, supporting
engineering and design activities
of AP projects worldwide from
the Houston, Texas location. Prior to working with
Air Products, Mr. Daru was a Technical Director in
mechanical engineering at Fluor Corp. in Sugar Land,
Texas. He has more than 30 yr of experience in the
engineering, designing and specifying of static
equipment in the refining, oil and gas, petrochemical
and chemical industries. Mr. Daru has produced more
than 10 publications in his field and holds a BS degree
in mechanical engineering from SVNIT in Surat, India.
Mr. Daru is a Registered Professional Engineer in the
states of Texas and Louisiana. The author can be
reached at Kuntak.Daru@gmail.com.
ANILKUMAR PANCHAL is an
Independent Consultant in
Mumbai, India. He has more than
15 yr of hands-on experience as a
Mechanical Design Engineer in
butyl rubber, gasification, ethane
cracker, chlorinated PVC and various
revamp projects. He previously worked for L&T Heavy
Engineering, Bechtel India Ltd., Jacobs Engineering,
Reliance Industries Ltd. and KIPIC, Kuwait. He holds
a BS degree in mechanical engineering and an
MS degree in industrial process equipment design.
He is a Certified Chartered Engineer and Professional
Engineer in India. The author can be reached at
anil0208@gmail.com.
PUNITA GALA is a Senior Design
Engineer at Reliance Industries Ltd.
and is part of the project
management team. She has worked
on benzene recovery units, extract
hydrotreater units, SCAN-Finer
units, as well as pressure vessels,
FIG. 4. Acceptable construction of expansion bellow (A) and unacceptable construction (B and C).
40 APRIL 2022 | HydrocarbonProcessing.com
shell-and-tube heat exchangers and packaged items.
Prior to Reliance Industries Ltd., she worked for
Bechtel India and Larsen & Toubro Ltd. Ms. Gala
graduated from L. D. College of Engineering,
Ahmedabad, India, in mechanical engineering.

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