A=Mass Flow Rate of GasDesign Gas Mass Velocitycap A equals the fraction with numerator Mass Flow Rate of Gas and denominator Design Gas Mass Velocity end-fraction
is applied for columns with fewer than 15 theoretical stages. Pressure Drop Analysis
HTU represents the physical mass transfer efficiency of the packing phase. It depends on gas and liquid velocities, diffusivity, and packing characteristics. While HTU can be rigorously calculated using the Onda Correlation, industry engineers often use conservative empirical baselines (e.g., an HTU of 1.5 to 2.5 feet for highly soluble gases like HClcap H cap C l in water). Step 6: Estimate Pressure Drop
Z=HTU⋅NTUcap Z equals cap H cap T cap U center dot cap N cap T cap U
Scrubbers are essential for controlling pollutants in many industries, from chemical plants to power generation facilities. However, designing them properly can be a complex task that requires balancing many factors. Microsoft Excel remains one of the most practical tools for this work, offering engineers the flexibility to build custom calculation sheets that fit their specific needs. This guide will walk you through everything you need to know about scrubber design calculations in Excel, from essential formulas to best practices that will save you time and prevent costly mistakes.
Every accurate wet scrubber calculation starts with defining the baseline parameters of the waste gas stream and the liquid solvent.
These practices create maintenance problems and make formulas harder to trace. Use proper formatting and tables instead.
The vessel diameter is determined by the gas flow rate and the chosen gas velocity:
The best spreadsheet is a validated spreadsheet. Do this:
The height of the packed bed depends on how easily the contaminant transfers from the gas to the liquid. This is calculated using the and the Height of a Transfer Unit (HTU) .
ρg=P⋅MwR⋅Trho sub g equals the fraction with numerator cap P center dot cap M sub w and denominator cap R center dot cap T end-fraction
Create a table with: | Packing Type | Material | Size (in) | Fp (ft²/ft³) | a (m²/m³) | ε (void fraction) | |--------------|----------|-----------|--------------|-----------|-------------------| | 1" Pall ring | PP | 1 | 56 | 207 | 0.92 | | 2" Intalox | Ceramic | 2 | 40 | 102 | 0.74 |
A custom Excel model provides transparent formulas, instant sensitivity analysis, and zero licensing overhead. This comprehensive guide breaks down the core engineering physics and step-by-step mathematical algorithms required to build the best, audit-ready packed bed scrubber design calculation spreadsheet. 1. Core Process Chemistry and Gas Laws
Before calculating dimensions, gather your baseline process data. In your Excel sheet, dedicate an "Inputs" section for the following variables: Gas Flow Rate ( Qgcap Q sub g
Use Data Validation to select:
Use the generalized pressure drop correlation.
Using the (simplest for Excel):