Process Equipment Design -I — Winter 2022

Estimate the optimum pipe diameter for a flow of dry chlorine gas of 10000 kg/hr at 6 atm a and 20 oC through carbon steel pipe.

Explain concept of NPSH in pumping system. If (NPSH) is less than A (NPSH) , then suggest corrective action to make (NPSH) greater than R A (NPSH) R

Discuss step wise design procedure for shell and tube heat exchanger without phase change.

Discuss the five standard locations of pressure taps in orifice meter.

Explain Tinker’s Flow Model.

In vertical thermosyphon reboiler recirculation ratio is fixed by trial and error method. Discuss in detail how to find or fix the recirculation ratio in the following conditions: 1. ΔPav > ΔPt 2. ΔPav << ΔPt 3. ΔPav ≈ ΔPt

1-2 shell and tube heat exchanger is used to cool methanol condensate from 95 °Cto 40°C. Flow rate of methanol is 100000 kg/h. Brackish water is used as coolant with temperature rise from 25 °Cto 40 °C. Property Methanol Brackish Water Heat Capacity, kJ/kg °C 2.84 4.2 Density, kg/m3 750 995 Viscosity, mN. s/m 0.34 0.8 Thermal conductivity, W/m °C 0.19 0.59 Choose 20mm od, 16 mm id, 4.88 m long cupro-nickel tubes with triangular pitch Pt = 1.25d . Based on overall heat transfer coefficient 600 W/m2 C O Calculate (1) Number of tubes (2) Shell Diameter Kand n for tube bundle diameter: (For triangular pitch Pt= 1.25d ) 1 1 o1 No. of tube side 1 2 4 6 passes K 0.319 0.249 0.175 0.0743 0.03651 n 2.142 2.207 2.285 2.499 2.6751 Take: F =0.85 and bundle diamerical clearance 68 mm t

Discuss selection criteria between kettle type and thermosyphon reboiler

Describe determination of minimum reflux ratio by McCabe-Thiele method.

Asaturated liquid, consisting of phenol, o-cresol, m-cresol with some xylenols, is fractioned to give a top product of 95.3 mole % phenol, 4.55 mole % of o-cresol and 0.15 mol % om-cresol. The bottom product contains 5.24 mol% of phenol. Total condenser is used. The composition of the feed and relative volatilities is given in the table. For a feed rate of 100 kmol/h complete the material balance over still and calculate the minimum reflux ratio. Component Average relative volatilities Feed ,Mole % Phenol 1.98 35 o-Cresol 1.59 m-cresol 1.00 30 xylenols 0.59

Discuss the criteria for fluid allocation in shell & tube heat exchanger.

Determine the minimum reflux ratio for the binary distillation at standard atmospheric pressure based on the following data: Feed = 100 kmol/hr has mole fraction of benzene= 0.4 and rest toluene. Feed is saturated liquid and mole fraction of benzene in distillate = 0.99 Mole fraction of benzene in residue required = 0.02, α = 2.25. av

Estimate minimum reflux ratio and minimum number of ideal stages needed for the butane-pentane splitter defined by the compositions given in table below. The column is operated at a pressure of 8.3 bar. The feed is at its boiling point. Top and bottom temperatures are 65 ˚Cand 120 ˚C respectively. Component Feed, Distillate, Bottom, Relative Relative Kmol/hr Kmol/hr Kmol/hr volatility volatility at 65 ˚Cat 120˚C Propane 5 5 ? 5.5 4.5 i-butane 15 15 ? 2.7 2.5 n-butane 25 24 ? 2.1 22 i-pentane 20 ? 19 1 1 n-pentane 35 ? 35 0.84 0.85

Describe effect of increase in reflux ratio on number of theoretical stages and utility requirement.

Write a brief note on packings used for packed bed absorption.

Discuss about the Liquid distributors, Liquid redistributors, Packing support and Hold-down plate for packed tower type absorber.

Discuss jet and downcomer flooding with figure.

Draw falling film type absorber and explain its advantages and disadvantages over the adiabatic type packed tower.

Explain design procedure for Absorption tower for finding the height (Cornell’s method) and diameter of column.

Explain the procedure to fix the operating pressure of distillation column.

List important industrial application of liquid-liquid extraction

Discuss design steps for a vertical decanter for extraction column.

Explain the terms flooding and weeping in distillation column.

Discuss the desirable solvent properties for liquid-liquid extraction.

Discuss the steps for process design of counter current multistage extractor.