Engineering reference for Indian students

Core process

Process Calculations

5 self-contained study topics — notes, diagrams, formulas, and worked examples for exams and GATE.

Topics

Material Balance
Material Balance — Recycle and purge alter fresh feed Part of Process Calculations (material and energy balances), using notation from Stoichiometry — Bhatt & Vora. Important for B.Tech semester exams and GATE stoichiometry and recycle streams.
Energy Balance
Energy balances close the first law on a flowing system: heat added minus shaft work equals the change in enthalpy (plus small kinetic and potential terms), with all enthalpies referred to one common datum.
$Adiabatic reactor: Q = 0; isothermal: \Delta T \approx 0 with heat exchange$
Recycle and Purge Calculations
Recycle-and-purge problems distinguish two conversions: overall (based on fresh feed) and single-pass (based on reactor inlet). A purge stream is added to bleed accumulating inerts and is sized so inert generation equals inert removal at steady state.
Combustion Calculations
Combustion calculations balance a fuel against air, compute the stoichiometric oxygen from the C, H and S content, add a stated percentage of excess air, and then report flue-gas composition on either a wet or a dry (Orsat) basis.
$Excess air % = \frac{(O_{2} supplied - O_{2} stoichiometric)}{O_{2}} stoich \times 100$
Humidity and Psychrometry
Psychrometry describes moist air using absolute humidity (kg water per kg dry air) and relative humidity (partial pressure over saturation pressure); most problems are read directly off the psychrometric chart at the intersection of dry- and wet-bulb temperatures.