Calculators›Packed Column Design
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Packed Column Design Calculator

GPSA · Plant Processing of Natural Gas Ch. 9 · Packed Towers

Packed Tower Hydraulic Design
Sizes packed columns for absorption, stripping, and distillation using GPSA and Kister correlations. Calculates diameter from flooding velocity, HETP-based packing height, pressure drop (Strigle method), and liquid loading. Includes packing factor (Fp) data for Pall rings, IMTP, Raschig rings, and structured packing per GPSA 14th Ed. Section 19.

Process Conditions

MMSCFD
gpm
psia
°F

Fluid Properties

lb/ft³
lb/ft³
cP

Packing Selection

Pall Rings (Metal): Most common random packing. Good capacity (Fp=27-56), moderate HETP (2-4 ft). Ideal for amine treating and general absorption.

📚 Learn the Theory

Learn packing types, HETP calculations, and pressure drop design

Read Engineering Guide →

📐 Key Design Parameters

Fp (Packing Factor)
Higher Fp = lower capacity. Pall 2" = 27, IMTP 2" = 18, Structured 250Y = 28
HETP (Height Equivalent to Theoretical Plate)
1.5-2 ft (structured), 2-4 ft (random). Height = Stages × HETP
FLV (Flow Parameter)
(L/G)×√(ρG/ρL). Determines flooding curve position on GPDC chart
Cs (Capacity Factor)
From GPDC correlation: Cs = Vs×√(ρG/(ρL-ρG))
Flooding Velocity Correlation:
Vflood = Cs,flood × √((ρL-ρG)/ρG)
Design velocity typically 70-80% of flooding velocity

📊 Design Guidelines (GPSA)

Operating Limits

Flood Margin Design at 70-80% of flooding velocity
Min. Wetting (Random) 3-5 gpm/ft²
Min. Wetting (Structured) 1-2 gpm/ft²
ΔP Normal Operation <0.5 in H₂O/ft
ΔP Approaching Flood <1.0 in H₂O/ft
Redistributors Every 15-20 ft or 1.5×D (structured)

Packing vs. Trays Selection

✓ Packing preferred: Vacuum service (low ΔP), corrosive systems, foaming, low liquid rates (<5 gpm/ft²), large columns (>10 ft dia.)
✗ Trays preferred: Fouling/solids service, wide turndown requirements, very low surface tension liquids

⚙️ Common Applications

🧪 Amine Contactors: 2" Pall rings or IMTP, 15-25 ft packing height
💧 Glycol Dehydration: 1-2" random packing, 10-20 ft typical height
❄️ NGL Fractionation: Structured packing (Mellapak, Flexipac) for low ΔP
🏭 Acid Gas Removal: MDEA/DEA systems with high-capacity packing
⚗️ Sulfur Recovery: Claus tail gas treating with structured packing

Critical Design Considerations

🌊 Flooding Prevention
Never exceed 85% flood; monitor ΔP for early warning
💨 Liquid Distribution
Quality distributor essential; min. 40-100 drip points/ft²
📏 Bed Height Limits
Max 20-25 ft per bed; add redistributors for taller columns
🔧 Packing Support
Gas injection support plates; avoid liquid holdup at base
🧹 Fouling Mitigation
Consider larger packing size or trays for fouling services

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