The subject enables the students to apply the understanding of heat transfer mechanisms such as conduction, convection and radiation for understanding the performance of various heat transfer equipment such as heat exchangers, condensers, boilers, evaporators etc. used in almost all chemical and related industries.
1. Modes of Heat Transfer (32 hrs)
a) Conduction (12 hrs)
Fourier’s law, Thermal conductivity, Conductance, Flat wall, Multilayer flat wall, Hollow cylinder, Multilayer cylinder, log mean area, geometric mean area and Arthmatic mean area, Introduction to unsteady state conduction, Simple numerical problems in S.I. Units.
b) Convection (12 hrs)
Natural and forced convection, dimensional analysis, Pi theorem, physical significance of dimension less number. Reynolds No, Prandlt No., Nusselt No., Stanton No., Peclet No., Grashoff No., Dittus Boelter’s equation-simple numerical problems using Dittus Boelter equation. Fouling factor. Individual heat transfer coefficient and over, all heat transfer coefficient.
c) Radiation (8 hrs)
Reflection, absorption and transmission of radiation, Kirchoff;s law, Emissive power, Wein’s displacement law, Stefen Boltman law, heat transfered by radiation, exchange of energy between two parallel planes of different emissivity, Radiant heat transfer coefficient, Solar radiation, grey surfaces or grey body.
2. Heat Exchanger (12 hrs)
Log.-Mean-Tempature.-Difference(L.M.T.D.) for parallel or concurrent -flow, counter-current-flow, cross -flow, construction and description of
i) Double pipe heat exchangers.
ii) Shell & Tube heat exchanger
iii) Finned tube heat exchangers.
iv) Scale formulation and cleaning devices, Wilson’s plot (Simple Numerical Problems).
iv) Overall heat transfer coefficient
3. Evaporators (12 hrs)
Construction and description of
i) Horizontal tube types
ii) Standard vertical type or calendria type.
(a) Natural and forced circulation type.
(b) Entrainment and foam formation.