Week 5 MR Chapter 6 Fluid Flow Through
- Slides: 16
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. 19, 2020. • By either volunteer or class list. MARTIN RHODES (2008) Introduction to Particle Technology , 2 nd Edition. Publisher John Wiley & Son, Chichester, West Sussex, England.
Pressure drop-flow relationship Laminar flow: Darcy (1856) Hagen-Poiseuille: Tube equivalent diameter: Flow area = e. 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
A Sv = 6/x Carmen-Kozeny eq. : Turbulent flow:
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 (From Ergun equation) The volume of cake formed by the passage of unit volume of filtrate. (Eq. 6. 21, See Appendix 5 for derivation )
• Constant pressure drop filtration (Eq. 6. 23, see Appendix • Including the resistance of the filter medium 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 rc = rc(ps) Analysis of the pressure drop-flow relationship for a compressible cake
xsv = 792 mm.
