FLOW PATTERN

a good length of liquid path

a very long liquidpath

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

Overall efficiencyac

eqo N

NE

21010 log044923.0log27511.052782.0 oE

Efficiency correlation (O’Connell, 1946)

MURPHREE EFFICIENCY MODEL

Thus,

inout

inoutMV yy

yyE

*

inout

inoutML xx

xxE

*

1234 xxxxxout

It is possible to have

outout yy *

1MVE

SIEVE TRAY LAYOUT• Net area• Hole area• Active area

LIQUID PRESSURE HEADS ON SIEVE TRAY

dugradcrestweirpdc hhhhhh

PRESSURE HEADS ON BUBBLE CAP TRAY

COLUMN DIAMETER

v

vLflood Ku

2.0

20

sbCK

floodop ufractionu )( 3600netv

vop A

MWVu

4

)( 2DiaAnet

3600)(4

floodv

v

ufractionMWVDia

Estimate sbCL

v

v

Llv W

WF

from sbC VS

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.