Sheet 1 of 5

COLUMN DIAMETER / HYDRAULIC CHECK

Prepared by : Column Tag No. :Checked by : Job No. :Date : Client :

Project :

Input Data

Packing type = Pall metal ringsPacking size = 25 mm

Gas / Vapour PropertiesGas / Vapour flow rate, V = 3843 kg/h

= 1.0675 kg/s

= 3.9352

Liquid PropertiesLiquid flow rate, L = 2317 kg/h

= 0.6436 kg/s

= 769.87 Conversion :

= 0.0002218 0.2218 0.00022180

= 160

Calculation

== 0.0431

= 0.76

= 4.50

Trial % flooding == 41.0961

=

= 2.2198

Trial column c/s area =

= 0.4809

Gas / Vap. Density, V kg/m3

Liquid Density, L kg/m3

Liquid Viscosity, µL Ns/m2 Cp = Ns/m2

Packing factor, Fp m-1

Liq.-Vap. Flow factor, FLV (L / V) x ( V / L)

Design for an initial pressure drop of 20mm H2O /m packing

From K4 v/s FLV,

K4

K4 at flooding

( (K4 / K4 at flooding) ) x 100

Gas mass flow rate, Vm K4 . V ( L -- V)

13.1 Fp (µL / L)0.1

kg/m2.s

V / Vm

(Trial As)

m2

(1/2)

Sheet 2 of 5

Trial column dia., D = 0.7825 m D =

Round off 'D' to nearest standard sizeTherefore, D = 0.600 m

= 0.2827

% flooding = 69.8977

ConclusionGenerally packed towers are designed for 50% -- 85% flooding.If flooding is to be reduced,(i) Select larger packing size and repeat the above steps.OR(ii) Increase the column diameter and repeat the above steps.

(4/pi) x Trial As

Column C/S area, As m2 As = (pi/4) x D2

% flooding = Trial % flooding x (Trial As / As)

Sheet 3 of 5

HETP PREDICTION

Norton's Correlation : ln HETP = n - 0.187 ln + 0.213 ln µApplicable when, liquid phase surface tension > 4 dyne/cm & < 36 dyne/cmliquid viscosity > 0.08 cP & < 0.83 cP

Conversion :Input Data 0.017 N/m = 17 dyne/cmLiquid-phase Surface Tension, = 17 dyne/cm Norton's Correlation Applicable

Liquid Viscosity = 0.2218 cP Norton's Correlation Applicable

n = 1.13080

Calculation

ln HETP = 0.2802155

HETP = 1.323415 ft= 0.4033769 m

For separations, less than 15 theoritical stages, a 20% design safety factor can be applied.

Considering 20% safety factor, HETP = 0.4840523 m

For separations, requiring 15 to 25 theoritical stages, a 15% design safety factor can be applied.

Considering 15% safety factor, HETP = 0.4638834 m

Table 6.2Constant for HETP Correlation

Ref.:: Random Packings and Packed Towers ---- Strigle

Ref. : : Chemical Engineering, Volume-6 , COULSON & RICHARDSON'S