FLOW PATTERN
a good length of
liquid path
a very long liquid
path
high liquid–vapor
ratios
FLOW PATTERN
• Cross flow
• Double pass
SINGLE PASS
DOUBLE PASS
DOWN COMERS AND WEIRS
WEIR
• Straight Horizontal
• Adjustable
• Notched
DOUBLE PASS SLOPPED
DOWNCOMERS
MECHANICAL SUPPORTS
MANWAY
TRAY HYDRAULICS
CAPACITY GRAPH FOR A TYPICAL
BUBBLE-CAP TRAY
FLOW REGIMES
CLOSE-UPS
• Cellular foam
• Froth (Operating
regime)
CLOSE-UPS
• Emulsion regime
• Froth regime
TRAY EFFICIENCY
Eo 
N eq
Overall efficiencyN
ac
Efficiency correlation (O’Connell, 1946)
Eo  0.52782 0.27511log10   0.044923log10 
2
MURPHREE EFFICIENCY MODEL
EMV
yout  yin
 *
yout  yin
EML
xout  xin
 *
xout  xin
It is possible to have
*
yout
 yout
Thus,
EMV  1
xout  x4  x3  x2  x1
SIEVE TRAY LAYOUT
• Net area
• Hole area
• Active area
LIQUID PRESSURE HEADS ON
SIEVE TRAY
hdc  hp  hweir  hcrest  hgrad  hdu
PRESSURE HEADS ON BUBBLE CAP
TRAY
COLUMN DIAMETER
uop  ( fraction)u flood
u flood  K
V MWv
uop 
v Anet 3600
Anet  
 ( Dia) 2
4
 L  v
v
 
K  Csb  
 20 
0.2
Dia 
Estimate
W
Csb from Csb VS Flv  L
Wv
4V MWv
v ( fraction)u flood 3600
v
L
Capacity factor versus flow parameter
ADIOS!
• All of the references are provided during
class lectures.
• All of the pictures are taken from various
books and Websites solely for educational
purpose.
• The author is thankful to Dr, Syeda
Sultana Razia, associate professor, ChE,
BUET, for developing the core concept of
this presentation.