Page 290 - Fluid mechanics, heat transfer, and mass transfer

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SHELL AND TUBE HEAT EXCHANGERS

10.1 Heat Exchangers 271 & Heater: Supplying heat energy to a process stream,
10.1.1 Tube Pitch 285 for example, preheating a reactor or distillation
10.1.2 Baffles 287 column feed. Steam or a hot heat transfer fluid
10.1.3 Fouling 296 supplies the required energy.
10.1.4 Pressure Drop 308
& Chiller: One stream, a process fluid being con-
10.1.5 Shell Side Versus Tube Side 309
densed at subatmospheric temperatures and the other
10.1.6 Specification Sheet 311
a boiling refrigerant or process stream.
10.1.7 Log Mean Temperature Difference 311
10.1.8 Performance 317 & Plate Heat Exchanger: An alternative for shell and
10.2 Thermal Design of Shell and Tube Heat Exchangers 321 tube exchanger replacing shell and tube system by
10.2.1 Kern Method 321 alternating channels created by thinner plate parti-
10.2.2 «-NTU Method 322 tions for the flow of two fluids exchanging heat
10.2.3 Bell Delaware Method 324 between them. Plate heat exchangers are often used
10.3 Miscellaneous Design Equations 327 in low-viscosity applications with moderate de-
10.4 Annexure (TEMA Fouling Factors) 328 mands on operating temperatures and pressures,

typically below 150 C. Gasket material is chosen
to withstand both the operating temperature and the
properties of the processing fluid. Gasketed, brazed,
welded, semiwelded, or hybrid types are some
variations.
& Finned Tube/Extended Surface Heat Exchanger:
10.1 HEAT EXCHANGERS
This is a class of compact heat exchangers in which
. Name different types and names of heat transfer equip- surface area (one side) of heat transfer equipment
ment and state their functions/applications. is increased by attaching fins or creating grooves/
& Shell and Tube Heat Exchanger: General name for a threaded surfaces or by other configurations. Used
commonly used heat transfer equipment involving for applications involving poor heat transfer that
exchange of heat between two fluids, one flowing on requires large surface area for a given duty, as in
the tube side and the other on the shell side, with no exchangers involving air or gases.
direct contact between them. This is the workhorse of & Cross-Flow Heat Exchanger: Shell side flow in a
process industry. heat exchanger is in the perpendicular direction
& Condenser: To condense steam or process vapors, instead of the customary counter or parallel flow,
using in most cases, cooling water for the purpose. used in most exchangers.
& Cooler: To cool hot streams/products from process, & Spiral Heat Exchanger: Heat transfer surfaces are
before sending to storage or other applications arranged in the form of a spiral to increase turbulence
requiring colder fluids for exampling, recycling in through increased shear by continuous direction
reactors or distillation units. On one side is process change. Used in special applications justifying
stream and on the other usually cooling water. increased costs.
& Air-Cooled Exchanger: Has an integral electric & Scraped Surface Heat Exchanger: Heat transfer
motor or fluid-powered fan for the cooling or heat surface involving highly viscous liquids is subjected
removal.

Fluid Mechanics, Heat Transfer, and Mass Transfer: Chemical Engineering Practice, By K. S. N. Raju
Copyright Ó 2011 John Wiley & Sons, Inc.

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