This is where Excel shines. Use the Generalized Pressure Drop Correlation (GPDC) or the K4 vs. Flow parameter chart.
Step A: Flow Parameter (X-axis)
$$F_p = X = \fracLG \times \sqrt\fracρ_gρ_l$$
Excel: =(L_G_ratio)*(SQRT(gas_density/1000)) (assuming liquid density ~1000 kg/m³)
Step B: Flooding K4 – You need a lookup table for your packing. Create a small table in Excel: | Packing Type | Flooding K4 at ΔP=42 mmH₂O/m | | :--- | :--- | | 1" Metal Pall Ring | 1.8 | | 2" Plastic Pall Ring | 1.2 | | 3" Ceramic Intalox | 0.9 |
Use VLOOKUP to fetch K4. For design, take 70% of Flooding K4.
Step C: Gas velocity $$V_gas (m/s) = \sqrt\fracK4 \times (ρ_l - ρ_g)13.1 \times F_p \times μ_l^0.1$$ Where $F_p$ = packing factor (from vendor).
Step D: Diameter $$D (m) = \sqrt\fracQ_gas / 36000.785 \times V_gas$$
The velocity at the scrubber throat ($u_t$) is the primary driver of collection efficiency. As hot gas accelerates through the throat, liquid is injected and atomized into fine droplets. The relative velocity between the gas and the droplets creates inertial impaction, capturing particles.
When dealing with hot gas, the Excel calculation must account for the following, often overlooked, factors:
Clients are sensitive to energy costs. The sheet must predict pressure drop across the packing.
The gas will cool to the adiabatic saturation temperature (typically 40°C to 70°C depending on water temperature).
Equation:
m_gas * Cp_gas * (T_in - T_out) = m_water * λ
Where λ is the latent heat of vaporization of water.
The search for "scrubber design calculation excel hot" is not about finding any spreadsheet—it is about finding the right thermodynamic engine. A standard isothermal calculator will overestimate efficiency and underestimate vessel size by a factor of 2 or more.
By building or purchasing an Excel tool that solves the adiabatic energy balance, corrects gas viscosity for temperature, and uses saturated gas volume for velocity calculations, you move from guessing to engineering.
Next Step: [Download the Pro-Tier "Hot Gas Venturi Scrubber Calculator" Excel Template (VBA Enabled)] – Includes psychrometric loop, material selector, and 3D output chart.
Author Bio: The author is a process engineer with 15 years of experience in cement kiln and incinerator scrubber retrofits. scrubber design calculation excel hot
Keywords: scrubber design calculation excel hot, venturi scrubber sizing spreadsheet, high temperature gas cleaning, adiabatic saturation Excel tool, packed bed scrubber thermal design.
Designing a wet scrubber for high-temperature ("hot") gas streams requires balancing pollutant removal efficiency with heat recovery and structural integrity
. Using Excel allows for iterative modeling of these complex thermal and chemical interactions. www.mchip.net Core Design Parameters
A proper design calculation must start with these foundational inputs: Gas Characteristics : Volumetric flow rate ( cap Q sub g ), inlet temperature ( cap T sub i n end-sub ), moisture content, and pollutant concentration (e.g., cap H sub 2 cap S cap S cap O sub 2 , or particulate matter). Removal Requirements : Desired outlet concentration ( cap C sub o u t end-sub ) and overall absorption efficiency ( Saturation State : For hot gases, calculating the saturation temperature ( cap T sub s a t end-sub
) and saturated volume is critical for sizing the shell diameter. www.mchip.net Step-by-Step Calculation Logic in Excel Gas Volume Correction
: Hot gas volume must be corrected to saturated conditions. For example, a 10,000 ACFM stream at 450°F may reduce to 7,500 ACFM upon saturation. Tower Sizing
: Determine based on the allowable gas velocity through the shell (typically 1–2 m/s or 500 ft/min).
: Calculated using the Height of a Transfer Unit (HETP) and the required Number of Transfer Units (NTU) based on absorption kinetics. Liquid-to-Gas (L/G) Ratio
: This ratio (typically 0.1 to 10) determines the volume of scrubbing liquid needed to handle the pollutant load and provide necessary cooling. Pressure Drop ( cap delta cap P : Use correlations like Norton’s Darcy-Weisbach
equation to ensure the system operates within fan/blower limits. : For hot gases, calculate the energy balance (
) to determine the cooling load or potential for heat recovery. www.mchip.net Excel Implementation Resources
For a professional starting point, utilize these established templates: EPA Cost & Design Spreadsheets US EPA Cost Calculation Spreadsheets
provide detailed tabs for Packed Bed and Wet Flue Gas Desulfurization (WFGD) parameters. Spray Tower Calculators : Marco Meloni offers a specialized Spray Tower Excel Sheet that covers removal efficiency and pressure losses. General Wet Scrubber Sheets This is where Excel shines
: Detailed sizing guides for diameter, plate thickness, and packing selection can be found on platforms like H2s Scrubber Design Calculation - MCHIP
Introduction
A scrubber is a type of air pollution control device that uses a liquid to remove contaminants and pollutants from a gas stream. The design of a scrubber involves several key calculations to ensure that it can effectively remove pollutants and meet emissions standards. In this write-up, we will discuss how to perform scrubber design calculations using Excel.
Scrubber Design Calculations
The design of a scrubber involves several key calculations, including:
Excel Calculation Template
To perform scrubber design calculations in Excel, we can create a calculation template that includes the following inputs:
The template can then be used to calculate the following outputs:
Step-by-Step Calculation Procedure
Here is a step-by-step procedure for performing scrubber design calculations in Excel:
Example Calculation
Here is an example calculation for a scrubber design using Excel:
Using the calculation template and step-by-step procedure, we can calculate the following outputs: Material Selection: While not a calculation, the output
Conclusion
Scrubber design calculations can be performed using Excel to ensure that a scrubber can effectively remove pollutants and meet emissions standards. By following a step-by-step calculation procedure and using a calculation template, engineers can quickly and accurately design scrubbers for a variety of applications.
The hum of the plant was usually a comfort to Elias, but today, the caustic scrubber
was screaming. Not literally, of course—though the high-pressure alarm on the control panel was doing a fine job of that.
The inlet gas temperature from the kiln had spiked, and the old design parameters were failing. If the liquid-to-gas ratio stayed this off-balance, the stack would start "yellow-smoking," and the EPA would be at the gates by noon.
Elias ducked into the site office, his boots clacking on the linoleum. He pulled up his master file: Scrubber_Design_Final_v4_HOT.xlsx
"Talk to me," he muttered, fingers flying across the mechanical keyboard. He didn't just need a fix; he needed a recalculation for adiabatic saturation
. As the hot gas hit the recirculating liquor, it would evaporate water instantly, cooling the gas but shrinking its volume and changing the density. The Inputs:
He punched in the new 450°F inlet temp and the soaring flow rate. The Magic:
The spreadsheet’s hidden VLOOKUPs pulled the physical properties of the gas. The NTU (Number of Transfer Units) cells turned a cautionary orange. The Solve:
He adjusted the packing depth from 10 feet to 14. The pressure drop calculation—the heart of the sheet—recalculated.
With a final tweak to the pump frequency on the screen, he watched the "Flood Point %" drop from a dangerous 92% to a stable 70%. He hit 'Save,' exported the setpoints, and ran back to the floor.
Ten minutes later, the alarm fell silent. The plume at the top of the stack turned from a ghost of a haze to invisible, clean air. Elias leaned against the steel railing, the heat of the tower radiating against his back, and smiled.
The math held. The Excel sheet, messy as it was, had saved the day. pressure drop across the packing for your own design?
