Scrubber Design Calculation Excel Hot -

Designing a scrubber, specifically for "hot" or high-temperature gas streams, requires accounting for gas humidification and volume changes before sizing the vessel. You can find pre-built templates on platforms like Scribd or Cheresources that handle these calculations. Core Calculation Steps for Hot Gas Scrubbers

For high-temperature applications, the "hot" gas must be cooled to its adiabatic saturation temperature before or during the scrubbing process. Gas Inlet Properties: Define your inlet gas temperature ( Tincap T sub i n end-sub

), flow rate, and pressure. Hot gases have lower density, which significantly increases the required tower diameter.

Saturation & Humidity: Calculate the saturated gas flow rate. For example, a gas at 400°F may have a saturation temperature around 127°F, which changes the volumetric flow rate ( Qsatcap Q sub s a t end-sub ) used for sizing.

Liquid-to-Gas (L/G) Ratio: This is the most critical design parameter. For venturi scrubbers, typical ratios are 7–20 gallons per 1,000 cubic feet of gas.

Tower Diameter: Use the gas velocity and pressure drop to find the cross-sectional area. The diameter ( ) is typically calculated as Pressure Drop ( ΔPcap delta cap P

): For venturi types, use the Hesketh or Calvert equations to ensure the fan can handle the resistance. Recommended Excel Templates

Excel calculation sheet for rating of a spray tower scrubber

🔥 Master Your Scrubber Design: Hot Gas Stream Excel Guide

Designing a scrubber for "hot" gas streams requires more than just standard absorption formulas. You must account for gas cooling, adiabatic saturation, and volume expansion. Use this structure to build a robust Excel calculator. 1. Core Inputs (The Essentials) Gas Stream Data: Inlet temperature ( Tincap T sub i n end-sub ), mass flow rate ( ṁgasm dot sub g a s end-sub ), and initial pollutant concentration ( Cincap C sub i n end-sub Target Efficiency: Desired removal percentage (e.g., 99%). Liquid-to-Gas (L/G) Ratio: Typically for wet systems. 2. Key Design Formulas for your Excel Cells Saturation Temperature ( Tsatcap T sub s a t end-sub

): The gas must be cooled before effective scrubbing. Calculate the adiabatic saturation temperature to determine the final volume. Scrubber Capacity:

Blower Capacity (per hour) = Total Air Flow Rate (m³) / Time. Removal Efficiency ( ): Excel Formula: =(Entry_Conc - Exit_Conc) / Entry_Conc. L/G Ratio: Use the Torch-Air standard of gallons per ft3f t cubed of air for high-performance units. 3. Pro-Tips for "Hot" Scrubber Sizing

Material Selection: Hot gas often requires exotic alloys or specialized FRP (Fiber Reinforced Plastic). Ensure your Excel includes a "Material Factor" lookup table.

Volume Expansion: Remember that hot gas occupies more volume (

). Your blower CFM must be sized for the actual temperature, not just standard conditions.

Water Evaporation: Calculate the water lost to evaporation to ensure your pump and hydro-tanks are sized correctly. scrubber design calculation excel hot

Looking for a pre-built template? Check out engineering resources like the Microsoft Support Guide for help with complex cell logic or Torch-Air's Engineering Blog for the full physics breakdown.

Wet Scrubber Design: Steps, Parameters, Calculation, Equations

To get a highly accurate wet scrubber design calculation Excel sheet, you must account for thermal effects, evaporation, and gas expansion when handling hot gas streams.

Below is the complete step-by-step framework to build your own robust design spreadsheet in Excel. 📊 Core Spreadsheet Input Parameters

To begin your calculations, set up an Inputs Section in your Excel sheet with the following variables: Gas Properties: Inlet Gas Flow Rate ( Qg,incap Q sub g comma i n end-sub ) in or CFMcap C cap F cap M . Inlet Gas Temperature ( Tincap T sub i n end-sub ) in ∘Craised to the composed with power cap C . Gas Molecular Weight ( MWgcap M cap W sub g ). Liquid Properties: Scrubbing Liquid (usually water) Inlet Temperature ( TL,incap T sub cap L comma i n end-sub ). Liquid Density ( ρLrho sub cap L ). Pollutant Data: Inlet Concentration ( Cincap C sub i n end-sub ). Desired Outlet Concentration ( Coutcap C sub o u t end-sub ) or target efficiency. ⚙️ Step-by-Step Design Calculations

Use these sequential formulas to build out the active calculating cells in your Excel grid. 1. Hot Gas Quenching & Saturation

Hot gases will immediately evaporate a portion of the scrubbing liquid upon contact, cooling the gas to its adiabatic saturation temperature. Excel Goal: Calculate the saturated gas flow rate ( Qg,satcap Q sub g comma s a t end-sub ).

Concept: Use the ideal gas law to account for volume shrinkage due to cooling, balanced against volume increase from added water vapor. Formula Clue: 2. Tower Diameter (Flooding Velocity Method)

To prevent the liquid from being blown out of the top of the scrubber, you must calculate the tower's cross-sectional area based on the gas velocity. Action: Calculate the Flooding Gas Velocity ( Ufcap U sub f ) using the Sherwood-Lobo Correlation. Excel Formula:Set your operating velocity ( Uopcap U sub o p end-sub ) at 60% to 70% of the flooding velocity.

Tower Area (A)=Qg,satUopTower Area open paren cap A close paren equals the fraction with numerator cap Q sub g comma s a t end-sub and denominator cap U sub o p end-sub end-fraction

Diameter (D)=4×AπDiameter open paren cap D close paren equals the square root of the fraction with numerator 4 cross cap A and denominator pi end-fraction end-root 3. Packing Height (Mass Transfer)

This determines how tall your packed bed needs to be to achieve your removal efficiency. Formula:

HTU (Height of a Transfer Unit): Characterizes the mass transfer efficiency of your chosen packing material. NTU (Number of Transfer Units): for lean systems. 4. Liquid-to-Gas (L/G) Ratio

For effective particulate and acid gas removal, typical L/G ratios range from 1 to 3 liters of liquid per cubic meter of gas.

Ensure your pump sizing in Excel accounts for this total volume. ⚠️ Critical Checks for "Hot" Gas Scrubbers If your incoming gas is over 150∘C150 raised to the composed with power cap C ( 300∘F300 raised to the composed with power cap F Module A: Sizing & Diameter The diameter of

), you must build these safety checks into your Excel sheet:

Materials of Construction (MOC): Standard fiberglass (FRP) or plastics like PVC will melt. Your spreadsheet should flag temperatures and recommend High-Temperature FRP, Hastelloy, or a brick-lined quench section.

Make-up Water Rate: Account for massive water loss due to evaporation. Your Excel sheet must calculate: .

To help me tailor a specific set of formulas or a ready-to-copy tabular layout for your sheet, could you tell me: What is the inlet temperature of your hot gas? What specific pollutant are you trying to scrub (e.g., SO2cap S cap O sub 2 , HClcap H cap C l , or just fly ash/dust)? Do you prefer your calculations in SI units (Celsius, ) or Imperial units (Fahrenheit, CFMcap C cap F cap M )?

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

The design of a wet scrubber—whether for particulate removal or gas absorption—requires a systematic calculation process to determine critical dimensions and operational parameters. Utilizing a structured Excel spreadsheet

allows engineers to quickly iterate through design variables like gas flow rates, temperature, and pressure drops to find an optimal configuration. 1. Define Design Inputs and Gas Conditions

The first step is establishing the "source" data. In an Excel sheet, these are typically grouped in a dedicated "Inputs" tab. Gas Stream Properties : Include the inlet volumetric flow rate (e.g., in ), inlet temperature, and pressure. Saturation Calculations

: For hot gases, the scrubber will saturate the stream. You must calculate the saturated gas flow rate cap Q sub s a t end-sub ) and temperature ( cap T sub s a t end-sub

) using a psychrometric chart or humidity ratios. The scrubber is sized based on this saturated outlet volume, not the hot inlet volume. Target Efficiency : Define the required collection efficiency (e.g., for particulates) based on regulatory standards. 2. Determine Column Diameter The column diameter ( ) is primarily a function of the gas velocity required to avoid flooding while maintaining contact time. Calculation

: Divide the saturated volumetric flow rate by the allowable shell velocity (typically around for spray towers). Cross-Sectional Area ( cap A sub s

cap A sub s equals the fraction with numerator cap Q sub s a t end-sub and denominator v end-fraction Diameter (

cap D equals the square root of the fraction with numerator 4 cross cap A sub s and denominator pi end-fraction end-root Hydraulic Check : For packed towers, the Excel sheet should check the % Flooding (typically designed for

) using correlations like Norton’s to ensure the gas can move through the packing without pushing the liquid back up. 3. Calculate Tower Height and Packing

The height ensures sufficient contact time between the gas and the scrubbing liquid. Wet scrubber design calculation xls If t_e &gt

Module A: Sizing & Diameter

The diameter of a vertical packed scrubber is determined by the gas velocity relative to the flooding point.

Flooding Velocity Calculation: Use the Sherwood-Leva-Eckert correlation (often visualized on the Generalized Pressure Drop Correlation curve).
- Excel Formula Logic: Calculate the X-axis (Flow parameter: $L/G \times \sqrt\rho_g/\rho_l$) and Y-axis (Flooding parameter).
- Lookup: Many Excel sheets use a lookup table to interpolate the flooding curve values based on the packing factor (F).
Operating Velocity: Typically, scrubbers operate at 50–75% of the flooding velocity.
Diameter Result: $Area = Q_gas / Velocity$; $Diameter = \sqrt(4 \times Area) / \pi$.

3. Pressure Drop (Venturi Scrubber – Best for Hot Gases)

For high-temperature, dirty gases, the Venturi scrubber is king. The classic Calvert Equation for pressure drop (ΔP) is: ΔP = 1.03 * v_g^2 * (L/G) * (ρ_l/ρ_g)^0.5

Excel Implementation: Create a dynamic lookup that adjusts gas density (ρ_g) for temperature. A common mistake is using density at standard conditions. Use ρ = P*MW / (R*T) in Kelvin.

10. Output Summary Sheet – “Hot Scrubber Design Report”

Automatically populated, ready to print or share:

| Parameter | Value | Unit | |-----------|-------|------| | Gas flow rate (actual @ T,in) | 25,000 | m³/h | | Inlet gas temperature | 850 | °C | | Outlet gas temperature | 72 | °C | | Evaporation rate | 2.8 | L/s | | Scrubber type | Venturi | - | | Pressure drop | 12.4 | kPa | | Overall efficiency (2 µm) | 96.3 | % | | d50 cut diameter | 0.85 | µm | | Vessel diameter | 1.8 | m | | Total installed cost (est.) | $187,000 | USD | | Annual operating cost | $34,200 | USD/year |

Step 2: Throat Design

The throat velocity must typically range between 60 m/s to 120 m/s (200–400 ft/s) for effective atomization.

Select Target Throat Velocity ($u_t$): Start with 80 m/s.
Calculate Throat Area ($A_t$): $$ A_t = \fracQ_actualu_t $$
Calculate Throat Diameter ($D_t$) (if circular): $$ D_t = \sqrt\frac4 \times A_t\pi $$
Excel Logic: Include an "Iteration Toggle" to adjust $u_t$ until a desired Pressure Drop is achieved.

1.0 Executive Summary

This document outlines the methodology for designing a Venturi Scrubber system intended for hot gas cleaning. The design focuses on removing particulate matter (PM) from high-temperature flue gases using a liquid spray. The accompanying Excel calculation tool utilizes iterative algorithms to determine the throat dimensions, pressure drop, liquid-to-gas ratio (L/G), and overall collection efficiency.

Module 4: Pressure Drop (ΔP) for Hot Gas – The Calvert Correction

Standard pressure drop correlations (e.g., Calvert or Semrau) were developed for ambient air. Hot gas has lower density and higher viscosity.

Density Correction: ΔP_hot = ΔP_ambient * (ρ_hot / ρ_ambient)

Excel Formula Example:

= IF(T_in > 200, DeltaP_ambient * ( (1.2) / ( (29/359) * (560/(T_in+460)) ) ), DeltaP_ambient)

Module 2: Volumetric Flow Correction Factor

This is where most "scrubber design excel" downloads fail. They treat volume as constant.

Formula: Q_actual = Q_inlet * (T_out + 460) / (T_in + 460) * (P_in / P_out)

For a typical hot application (Inlet: 600°F, Outlet: 160°F): Factor = (620) / (1060) = 0.585

Pro Tip for Excel: Create a dynamic named range that pulls T_out from your adiabatic solver. Your velocity (V = Q_actual / Cross-sectional area) must use the average of Q_inlet and Q_outlet for accurate pressure drop calculations.

Advanced Feature: Evaporation Time vs. Residence Time

For a truly "hot" scenario, you need a safety check.

Excel Calculation:

Residence time (t_r): Volume of scrubber (ft³) / Q_actual (ft³/sec).
Evaporation time (t_e): t_e = (ρ_l * d_p^2) / (8 * k_g * M_w * P_sat)

If t_e > t_r, the droplets evaporate completely before falling into the sump. You have created a steam explosion risk, not a scrubber.

Condition: t_r > 3 * t_e for safe operation.