Scrubbers require a minimum liquid flow to keep the packing wetted.
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
This is the critical design constraint.
$$ \Delta P = \fracu_t^2 \times L \times \rho_l1000 \times C_d \quad \text(Simplified units) $$ scrubber design calculation excel hot
A more robust Excel formula using the Hesketh Equation: $$ \Delta P \approx \fracu_t^2 \rho_g A_t^0.1331270 \times \left( L/G \right) $$ (Note: Ensure consistent units: Pa or in. w.c.)
Pressure drop is critical for fan sizing and operating cost. This module includes:
Live flag: “ΔP > 15 kPa? → Check fan power limit” Drop-down for Packing: Use Data Validation to select
Scenario: Kiln exhaust – 10,000 m³/h at 500°C, 2% dust (5 micron).
Result: The "cold" calculator would cause a gas velocity that is too high, massive re-entrainment, and pressure drop spikes. Your "hot" Excel sheet prevents this failure.
The pressure drop ($\Delta P$) represents the energy used to accelerate the liquid droplets to the gas velocity. This calculation utilizes the Hesketh or Calvert correlation. Scrubbers require a minimum liquid flow to keep
When a hot gas enters, water evaporates. If you don't account for this, you'll run dry.
Heat to remove: $$Q_sensible = m_g \times C_p,g \times (T_in - T_out)$$
Water evaporated: $$m_evap (kg/h) = \fracQ_sensible2257 , kJ/kg$$
Excel check: Add a cell that calculates Evaporation % of recirc flow. If > 3-5%, you need blowdown or a bigger pump.