Gas cleaning of fine acidic mist Which type of wet scrubber is particularly effective for arresting very fine sulphuric acid mist aerosols?

Introduction / Context:
Removing submicron acidic mists (e.g., H2SO4) from process exhaust is critical for environmental compliance and corrosion control. Selection of a scrubber depends on the target particle size and pressure drop one is willing to accept.

Given Data / Assumptions:

• Mist droplets are very fine (often < 2 μm).
• Acceptable pressure drop is higher for better capture efficiency.
• Liquid is compatible with sulphuric acid.

Concept / Approach:
Venturi scrubbers accelerate gas through a throat to very high velocities, atomizing the scrubbing liquid into extremely fine droplets and producing intense turbulence. Collection of fine particles occurs by inertial impaction and diffusion, making venturis ideal for mists and fumes that defeat conventional packed beds.

Step-by-Step Solution:

Verification / Alternative check:
Performance correlations show increased collection efficiency with gas velocity and liquid-to-gas ratio in venturis, matching field practice for acid mist control.

Why Other Options Are Wrong:

• Packed wet and hollow wet scrubbers are suitable for gas absorption and larger droplets; capture of fine mist is limited at moderate pressure drops.
• Co-current describes flow orientation, not a specific high-efficiency mist control device.

Common Pitfalls:
Neglecting demisters downstream; venturi-generated fine droplets must be separated to prevent carryover. Also ensure materials of construction resist acidic environments.

Final Answer:
venturi