Reference no: EM131394066

Instructions: Solve the following problems, showing all the steps you made in the procedure.

Problem 1:

A column packed with 50 mm in ceramic Pall ring is to be design for the following vapor and liquid conditions:

Data:

	Vapor	Liquid
Mass flow rate , kg/h	525	1360
Density, kg/m3	1.182	1000
Viscosity, kg/m-s	1.78x10-5	1.00x10-3
Molecular weight	28.4	18.02
Surface tension, kg/s2		2.401x10-2

The column is operated at 110 kPa and 303 K. The process carried out with 69 percent of the flooding velocity.

Units of kinematic viscosity are m²/s.

Use the figure (Y vs. X): G²F_Pμ_L^0.1ψ/ρ_G(ρ_L-ρ_G)g_c vs. L'/G'(ρ_G/ρ_L-ρ_G)^0.5

Determine:

1. Molar flow rate.

2. The vapor and liquid superficial velocities at the loading and flooding points.

3. The void fraction.

4. The specific liquid holdup at the loading point.

5. The specific pressure drop at the loading and flooding point.

6. The column inside diameter for operation at the loading point.

7. The dry-gas pressure drop (Pa/m).

8. The liquid and gas mass velocity (kg/m²-s).

9. k_L and k_y.

10. The volumetric gas-phase and liquid phase mass transfer coefficients.

11. HTU (H_tG)

12. N_tG

13. Packed height, Z in m.

14. Give some characteristics from the packing used in this design.

Problem 2: Design of a sieve tray column

Carbon disulfide, CS₂, used as a solvent in a chemical plant, is evaporated from the product in a dryer into an inert gas (essentially N₂) in order to avoid an explosion hazard. The CS₂-N₂ mixture is to be scrubbed with an absorbent hydrocarbon oil (C₁₈H₃₈). The gas will flow at the rate of 0.45 m³/s at 297 K and 1 atm. The partial pressure of CS₂ in the original gas is 55 mmHg, and the CS₂, concentration in the outlet gas is not to exceed 0.55%. The oil enters the absorber essentially pure at a rate 1.3 times the minimum, and solutions of oil and CS₂ follow Raoult.s law.

Give a sketch of the countercurrent tower.

	MM	ρ (kg/m3)	P* (mmHg)	μ	σL (N/m)	Difussivity (cm2/s)
Oil	254	810		4 cP	0.030	0.765x10-5
Gas			346	1.7x10-5 (kg/m-s)		0.114

Foaming factor: 0.85

Tray spacing (t): 0.5 m

Hole diameter (d₀): 5 mm

Equilateral-triangular pitch: 12 mm centers punched in sheet metal.

Stainless steel metal: 2.5 mm thick

Design for a gas velocity which is 75% of the flooding velocity.

h_w: 5.0 cm

L_Smin is 5.95 mol/s

Assume isothermal operation, 297 K.

Assume equilibrium and operating lines. Graph Y vs X.

Results: Give all results in a

Liquid flow rate (kg/s):

Diameter (m):

Plate spacing (m):

Total cross-sectional area (m²):

Downcomer area (m²):

Details of the tray design:

Active area over the tray (m²):

Weir length (m):

Distance from tray center to weir (m):

Total hole area (m²):

h_d (cm):

h_I (cm):

h_σ (cm):

h_t (cm):

ΔP_G (Pa/tray)

F_r0:

Entrainment (E):

Entrainment mass flow rate (kg/s):

E_OG:

E_MG:

E_MGE:

Number of ideal trays.

Number of real trays required.

Give graphical solution and analytical solution

Conversions:

1.0lbm = 453.6 g

1.0 m= 3.2808 ft

1.0 m³ = 35.31 ft³

g = gc (in American system)

1 cP = 0.001 Pa-s

1.0 dyne = 0.00001 N