UCH 801 PROCESS ENGINEERING & PLANT DESIGN
Course Instructor
Dr. Sanjeev Kumar Ahuja
Associate Professor
Department of Chemical Engineering
Thapar Institute of Engineering & Technology, Patiala
(Deemed to be University)
March 3, 2023
DOF Mixing Process
Q. Several streams are mixed as shown in Figure below.
Carry out a degree of freedom analysis and solve.
Friday, March 3, 2023
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• Unknowns:A,B,C,D,E,4 Comp. of D=9
• MBs: 5+5=10
• Nd=-1, over-specified
OVERALL ENVELOPE
• Nv=4, Nr=5
• Nd=-1, over-specified
• A,B,C,D,E=1.66, 0.83, 2.49, 0.95,1.38 kg/s
Friday, March 3, 2023
THAPAR UNIVERSITY, PATIALA
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Multiple units (reacting system)
Friday, March 3, 2023
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Solution
• Basis: I h or P = 6205 lb mol
• Overall Envelope: 5 unknowns (A*, G, A, W, F); 5 MBs (5 elements)
• Overall MB (Elemental)
In
G(0.96)4 + G(0.02)2 + F (0.47) 2 (note)
A(0.79)(2) + A*(0.76)(2)
A(0.21)(2) + A*(0.20 + 0.04)(2) + G(0.02)(2)
F(0.03)
G(0.96 + 2X0.02 + 0.02) + F(0.50) + 0.04A*
H
N
O
S
C
•
Friday, March 3, 2023
F = 207 lb mol/h
Out
= W(2)
= 6205(0.8493)(2)
= 6205 (0.0413 + 0.001 + 0.1084)(2) + W
= 6205 (0.0010)
= 6205(0.1084)
G = 498 lb mol/h
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Thank you