week # 5 mr chapter 6 fluid flow through a packed … chapter 6 fluid flow through a packed bed of...
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Week # 5
MR Chapter 6
Fluid Flow Through a Packed Bed of Particles
• Tutorial # 5
• MR #6.1, 6.3, 6.5, 6.7,
• To be discussed on Feb. 21,
2018.
• By either volunteer or class list.
MARTIN RHODES (2008)
Introduction to Particle
Technology , 2nd Edition.
Publisher John Wiley & Son,
Chichester, West Sussex,
England.
Pressure drop-flow relationship
/U Ui
Tube equivalent diameter:
Hagen-Poiseuille:
Laminar flow:
2eH K H
Flow area = A; wetted perimeter = SBA;
SB: Particle surface area per unit volume of the bed.
Total particle surface area in the bed = SBAH
For packed bed, wetted perimeter = SBAH/H = SBA
Darcy (1856)
Carmen-Kozeny eq.:
Turbulent flow:
(1 )v BS S
A
Sv = 6/x
General equation for turbulent and laminar flow
Ergun eq.
Non-spherical particles
Friction factor versus Reynolds
number plot for fluid flows
through a packed bed of spheres
Filtration
• Incompressible cake
(Eq. 6.21, See Appendix 5
for derivation )
(From Ergun equation)
• Constant pressure drop filtration
• Including the resistance of the filter medium
(Eq. 6.23, see Appendix
5 for derivation )
(Eq. 6.27, see Appendix 5
for derivation )
Washing the cake
Removal of filtrate during washing of the filter cake
Compressible cake
Analysis of the pressure drop-flow relationship for a compressible cake
rc = rc(ps)
xsv = 792 mm.