Venturi Scrubber Design Calculation Xls Upd Jun 2026

Venturi Scrubber Design Calculation: A Comprehensive Engineering Guide Venturi scrubbers are highly efficient wet scrubbing systems used to remove fine particulate matter and gaseous contaminants from industrial exhaust streams. Designing these systems requires precise calculation of geometric dimensions, pressure drop, liquid injection rates, and collection efficiency. This technical guide outlines the fundamental engineering equations and parameters used to build a robust Venturi Scrubber Design Calculation spreadsheet (XLS). 1. Fundamental Design Principles and Parameters A Venturi scrubber consists of three primary sections: a converging section, a throat, and a diverging section. The gas stream accelerates in the converging section, reaches maximum velocity in the throat, and decelerates in the diverging section. Liquid is introduced either at the inlet or directly into the throat, where the high-velocity gas atomises the liquid into fine droplets to capture particles. Key Design Inputs: - Actual gas flow rate (Q_g, m³/s or ACFM) - Gas temperature and pressure - Gas density (ρ_g) and viscosity (μ_g) - Particle density (ρ_p) and particle size distribution (d_p) - Required collection efficiency (η) 2. Throat Velocity and Geometric Sizing The throat is the most critical part of the Venturi scrubber. The gas velocity in the throat typically ranges from 45 to 120 m/s (150 to 400 ft/s). High throat velocity increases particulate collection efficiency but also increases the pressure drop across the system. To calculate the throat area (A_t): A_t = Q_g / V_t Where: - A_t = Throat cross-sectional area (m²) - Q_g = Volumetric gas flow rate at actual throat conditions (m³/s) - V_t = Selected throat gas velocity (m/s) For a circular throat, the diameter (D_t) is derived as: D_t = √((4 * A_t) / π) The converging section typically features an inclusion angle of 21 to 28 degrees to smoothly accelerate the gas. The diverging section typically features an inclusion angle of 5 to 7 degrees to maximise static pressure recovery and prevent flow separation. 3. Liquid-to-Gas Ratio (L/G) The liquid-to-gas ratio determines the volume of scrubbing liquid required per unit volume of gas. For Venturi scrubbers, the L/G ratio generally ranges from 0.7 to 2.7 L/m³ (5 to 20 gal/1000 ACF). Total Liquid Flow Rate (Q_l) calculation: Q_l = Q_g * (L/G) Where: - Q_l = Volumetric liquid flow rate (L/s or GPM) 4. Pressure Drop Calculation Pressure drop (ΔP) is the primary determinant of operating cost and particulate collection efficiency. The most widely accepted empirical model for predicting pressure drop is the Calvert equation: ΔP = 5.02 * 10^-5 * (V_t)^2 * (L/G) Where: - ΔP = Pressure drop in cm of water column (cm w.c.) - V_t = Throat gas velocity (m/s) - L/G = Liquid-to-gas ratio (L/m³) Alternatively, the Hesketh equation provides another standard approach for industrial design: ΔP = ((V_t)^2 * ρ_g * A * (L/G)^0.78) / 1270 Where: - ΔP = Pressure drop in inches of water column (in. w.c.) - ρ_g = Gas density (lb/ft³) - A = Empirical cross-sectional area factor 5. Particulate Collection Efficiency Collection efficiency is highly dependent on the aerodynamic diameter of the target particles and the inertial impaction parameter (ψ). The impaction parameter represents the ratio of a particle's inertial force to the aerodynamic drag force acting on it: ψ = (C * ρ_p * (d_p)^2 * V_t) / (9 * μ_g * d_d) Where: - C = Cunningham slip correction factor - ρ_p = Particle density (kg/m³) - d_p = Particle diameter (m) - μ_g = Gas viscosity (kg/m·s) - d_d = Mean droplet diameter (m), often predicted via the Nukiyama-Tanasawa equation The fractional efficiency (η) for a specific particle size can then be calculated using the Johnstone equation: η = 1 - exp(-k * (L/G) * √ψ) Where k is an empirical tuning constant specific to the geometry and operating characteristics of the scrubber. 6. Implementing the Calculations into Excel (XLS) To construct an updated, dynamic Venturi Scrubber Design Calculation spreadsheet, organize the tabs into a logical workflow: - Documentation Tab: Outlines unit conventions, standard constants, and version control updates. - Inputs Tab: Cells for gas flow rate, temperatures, pressures, gas composition, and target particle characteristics. - Calculations Engine: Formulate cells to automatically calculate gas density, actual volumetric flow, throat dimensions, minimum required pressure drop, and fluid requirements using the equations listed above. - Outputs Tab: Summarizes the required fan power (based on ΔP and gas flow), pump power (based on Q_l and system head), geometric specifications, and expected overall efficiency. By automating these formulas within an XLS template, process engineers can quickly execute iterative sensitivity analyses to optimize the trade-offs between fan power consumption and emission compliance limits. Use code with caution. Share public link

Warning alerts if the throat velocity is too low (poor collection) or too high (excessive re-entrainment).

By following the guidance provided in this article, designers can create effective venturi scrubber designs that meet regulatory requirements and minimize environmental impact.

cap delta cap P equals 0.532 center dot v sub t squared center dot rho sub g center dot cap A sub t to the 0.133 power center dot open paren 0.56 plus 16.6 center dot the fraction with numerator cap Q sub l and denominator cap Q sub g end-fraction plus 40.7 center dot open paren the fraction with numerator cap Q sub l and denominator cap Q sub g end-fraction close paren squared close paren Typical Ranges: venturi scrubber design calculation xls upd

While Excel spreadsheets remain a powerful and transparent tool, the key "upd" in venturi scrubber design is the shift toward real-time simulation. By following the structured, step-by-step methodology—defining requirements, calculating droplet size and impaction parameters, and then solving for efficiency and pressure drop—you can create an effective design using either a classic spreadsheet or a modern web-based calculator.

) is the most critical factor driving the operating cost of a Venturi scrubber. The Calvert model provides an accurate estimation of pressure drop across the throat:

Gas properties, liquid properties, and target removal efficiency. Liquid is introduced either at the inlet or

An efficient tool must incorporate several foundational engineering formulas: Gas Velocity in Throat ( Vtcap V sub t ):

Kp=C⋅ρp⋅dp2⋅vt9⋅μg⋅d0cap K sub p equals the fraction with numerator cap C center dot rho sub p center dot d sub p squared center dot v sub t and denominator 9 center dot mu sub g center dot d sub 0 end-fraction = Cunningham slip correction factor ρprho sub p = Particle density ( kg/m3kg/m cubed = Particle diameter ( The overall penetration ( ) of particles through the scrubber throat is derived by:

To build a reliable calculation tool, you must define the following input variables: Usually measured in Actual Cubic Feet per Minute (ACFM). Gas Density ( ρgrho sub g ): Critical for pressure drop calculations. Baisakhi (harvest rituals)

= Mean droplet diameter (calculated via the Nukiyama-Tanasawa equation). 5. Implementation in Excel (XLSX/XLSM)

– Ram Navami, Baisakhi (harvest rituals), Summer drinks (aam panna, shikanji)