In gas cleanup for coke-oven gas, which device is most suitable for removing trace liquid tar fog (submicron to micron droplets)?

Introduction / Context:
Coke-oven gas contains mist-like tar droplets after primary cooling. To meet downstream specifications, an efficient fine-aerosol collector is required.

Given Data / Assumptions:

• Droplets are small (fog) and sticky.
• Pressure drop and fouling are practical concerns.

Concept / Approach:
Electrostatic precipitators impart electrical charge to droplets and collect them on grounded plates, achieving high efficiency on fine mists with moderate pressure drop. Cyclones are ineffective for submicron aerosols; strainers are for coarse debris.

Step-by-Step Solution:
Identify particle size regime (mist/fog).Select a device effective for submicron droplets: ESP.Confirm suitability for sticky tar aerosols.

Verification / Alternative check:
Coke plant gas-cleaning trains routinely include ESPs for tar-fog removal.

Why Other Options Are Wrong:
Cyclone: low efficiency for very fine droplets.Strainer: not an aerosol device.Bag filter: tar loading would blind quickly.

Common Pitfalls:
Using only mechanical separators; they cannot meet fine mist removal targets.

Final Answer:
Electrostatic precipitator