Scrubber Design | Calculation Excel Best [2021]

A wet scrubber is an essential environmental control device designed to remove pollutants (gases or particulates) from industrial exhaust streams. For Excel-based design, the "best" calculations typically follow the Generalized Pressure Drop Correlation (GPDC) or Norton’s Correlation for packed towers, and the Calvert or Hesketh equations for Venturi scrubbers. 1. Key Design Parameters for Excel

To build an effective Excel calculator, you must define the following input and output variables: Gas Stream Data: Volumetric flow rate ( Qgcap Q sub g ), temperature, pressure, and pollutant concentration. Scrubbing Liquid Properties: Flow rate ( ), density ( ρlrho sub l ), viscosity ( μlmu sub l ), and surface tension (

Packing Characteristics: Specific to packed towers, you need the Packing Factor ( Fpcap F sub p ) for materials like Intalox saddles or Pall rings. 2. Core Calculation Steps A. Column Diameter Calculation

The diameter is sized to prevent "flooding," where gas flow prevents liquid from descending.

Target Flooding: Most designs aim for 50% to 85% of flooding velocity. Formula Logic: Calculate the gas mass velocity (

) using the Vapor-Liquid Factor and the GPDC chart to find the flooding point. B. Column Height (Mass Transfer) NTU/HTU Method: The total height ( ) is calculated as NOGcap N sub cap O cap G end-sub

(Number of Transfer Units): Determined by the required removal efficiency. HOGcap H sub cap O cap G end-sub

(Height of a Transfer Unit): Determined by the mass transfer coefficient of the packing. scrubber design calculation excel best

HETP Method: Alternatively, use the Height Equivalent to a Theoretical Plate (HETP) for equilibrium-based calculations. C. Pressure Drop and Power Lec 20: Scrubber - Example problem

Finding high-quality, "interesting" technical papers often means looking for resources that combine rigorous engineering theory with practical tools like Excel. 

The most reliable resources for industrial scrubber design generally come from EPA manuals, professional engineering forums like ChE Resources, and specialized technical repositories like Scribd.  🔝 Top Recommended "Paper" & Tool Combinations 

1. EPA Air Pollution Control Cost Manual (Wet & Dry Scrubbers) 

This is widely considered the "gold standard" for professional design. It provides the deep theoretical "paper" context while being accompanied by a sophisticated Excel spreadsheet. 

Best For: Estimating capital and annualized costs for sulfur dioxide (SO2) and acid gas removal.

Key Insight: Includes detailed calculation methodologies for wet flue gas desulfurization (WFGD) and packed bed scrubbers. A wet scrubber is an essential environmental control

Resource: You can find the EPA Cost Calculation Spreadsheet and its corresponding manual on official government sites.  2. Marco Meloni’s Spray Tower Rating Guide 

If you want an accessible "paper" (PDF guide) paired with a functional Excel tool, this is a community favorite. 

Best For: Preliminary calculation of single-stage spray towers.

Key Insight: The guide (available in English and Italian) includes a theoretical appendix with bibliographical references for pressure loss and removal efficiency. Resource: Available via Meloni Marco's Engineering Blog.  3. HCL Packed Column Scrubber Design Guide 

This technical paper/spreadsheet combination is highly cited on Scribd for its step-by-step transparency. 

Best For: Designing a packed bed specifically for acid gas removal (like HCl).

Key Insight: Uses Norton’s Correlation for HETP (Height Equivalent to a Theoretical Plate) and calculates the exact column diameter based on flooding percentages. Venturi scrubber: pressure drop vs

Resource: Search for the Packed Column Scrubber Design Guide on Scribd.  🛠️ Key Calculations to Look for in Excel 

A "best" design sheet should allow you to input and calculate these variables: 

Wet Scrubber: Efficiency Сalculation, L/G Ratio, and Pressure Drop

5. Download-Ready Template Structure (Best Free Option)

While I cannot provide a direct file, the best public domain Excel scrubber calculator is the EPA’s Air Pollution Control Cost Estimation Spreadsheet (updated 2021). Search for:
"EPA OAQPS Control Cost Manual" + Excel scrubber

It includes:

• Venturi scrubber: pressure drop vs. fractional efficiency (Johnstone equation).
• Packed tower: Onda’s mass transfer coefficients.
• Spray tower: Souders‑Brown for diameter.

Pro tip: Copy only the calculation logic into your own workbook, then strip out VBA (if any) and replace with dynamic arrays (FILTER, SORT) for Excel 365.

Tab 1: Inputs

• Gas flow rate (ACFM or m³/h)
• Inlet/outlet concentrations (ppm or %)
• Liquid-to-gas ratio (L/G in gal/1000ft³ or L/m³)
• Packing type (dropdown: Raschig rings, Pall rings, Intalox)
• Operating T & P

Part 5: Case Study – HCl Scrubber in Excel

Problem: Design a scrubber to remove 99% of HCl from 10,000 m³/hr of air at 30°C, using water. Packing: 2" ceramic Intalox.

Excel steps:

1. Enter gas flow = 10,000 m³/hr, density = 1.16 kg/m³.
2. L/G ratio = start at 2 L/m³ (typical for HCl).
3. From packing DB: Fp = 40, a = 102 m²/m³.
4. Flooding calc yields G_flood = 2.8 kg/m²·s → Area = 0.99 m² → Diameter = 1.12 m.
5. Use 1.2 m ID for safety (70% of flood).
6. NTU = LN(0.02/0.0002) = 4.6 (assuming exit 20 ppm).
7. HTU from Onda correlation (embedded in Excel) = 0.45 m.
8. Packing height = 0.45 * 4.6 = 2.07 m. Add 30% safety: 2.7 m.
9. Pressure drop = 15 mmH2O/m → total = 40.5 mmH2O.
10. Results: Column = 1.2 m dia × 3.5 m shell (plus sump).

The entire design took 20 minutes in the Excel sheet.