Packed Bed flooding.pdf - Youngstown State University's Personal ...

(“Fluiddynamik von Kolonnen mit Modernen Füllkörpern und
Packungen für Gas/Flüssigkeitssysteme, Otto Salle Verlag, Frankfurt
am Main, and Verlag Sauerländer, Aarau, 1991), and by Mersmann
and Deixler [Chem. Ing. Tech. 58(1), 19 (1986)] apply to
second- and third-generation random packings as well as to some
structured packings.
Stichlmair and Fair (Distillation Principles and Practice, Wiley-
VCH, New York, 1998) show that liquid holdup is primarily a function
of the liquid Froude number, specific surface area of the
packing, and physical properties. They recommend the correction by
Engel, Stichlmair, and Geipel [Ind. Eng. Chem. Symp. Ser. 142, 939
(1997)].
EQUIPMENT FOR DISTILLATION AND GAS ABSORPTION: PACKED COLUMNS 14-77
(a) (b)
(c)
FIG. 14-70 Flashing feed and vapor distributors. (a) Bare nozzle. (b) Rounded V baffle. (c) Peripheral flash box—the box extends right around
the tower wall, with the collected liquid descending via downpipes to a liquid distributor below. (d) Gallery distributor—the feed enters the
gallery area (upper plate). (Parts a–c, courtesy of Sulzer Chemtech; part d, courtesy of Koch-Glitsch LP.)
U 2 Lap
(d)
µ 2 La 3 p
σa 2 p
1/6
hLo = 0.93� � � � 1/10
� � 1/8
� � ��
2 g ρLg 1000ρLg
(14-165)
where hLo = liquid holdup, fractional
UL = liquid superficial velocity, m/s
ap = packing specific surface area, m2 /m3 g = acceleration due to gravity, m/s
µ L = liquid viscosity, kg/(m⋅s)
σ=surface tension, mN/m
The Engel, Stichlmair, and Geipel correlation applies only in the
preloading regime. The packing geometry is represented in the