Subtopic: Steady state heat transfer in conduction, convection and radiation
Question Statement:
Log mean temperature difference (LMTD) correction factor (F) is applicable to
Options:
(A) Spiral tube heat exchanger
(B) Steam jacketed kettle
(C) Plate heat exchanger
(D) Evaporator tubes
Official Answer Key:
C
Step-by-Step Solution & Explanation
The LMTD correction factor F corrects the true counter-current LMTD for exchangers in which the flow is not purely co-current or counter-current — i.e. multi-pass and cross-flow arrangements.
A plate heat exchanger has multi-pass/cross-flow arrangements, so F < 1 must be applied.
A steam-jacketed kettle and evaporator tubes operate with one isothermal (condensing/boiling) fluid, for which F = 1 by definition; a spiral tube exchanger is essentially pure counter-current, again F = 1.
Practice This in Real CBT Exam Interface
Test yourself with the official TCS-iON palette, virtual calculator, and immediate performance analytics.