Why a Packed Scrubber Needs Controlled Airflow
A packed scrubber brings contaminated gas into contact with a suitable liquid. The fan maintains that gas flow, while the liquid and packing perform the contacting process.
Follow the air through the process
Gas rises as liquid descends
In this countercurrent tower, gas enters below the packing and rises through its open spaces. Liquid is distributed above and flows downward over the packing surfaces.
Packing creates contact area
The wetted surfaces create a large contact area. A target gas must transfer into a compatible liquid, sometimes with a chemical reaction. Water alone does not absorb every pollutant equally.
Remove carried droplets before discharge
Above the spray distributor, a mist eliminator separates liquid droplets carried by the rising gas. The captured liquid drains downward; this droplet removal differs from absorbing a gas molecule.
Too much flow can disturb the liquid
Gas and liquid rates must be matched to the packing. Excessive gas flow can hinder liquid drainage and increase carryover. Clogged or poorly wetted packing also changes the contact and resistance.
Airflow function
- Maintain gas flow through the wet packing so gas and suitable liquid can contact each other.
- Overcome the combined resistance of the tower, demister, duct and outlet.
- Support the specified operating range while the absorption chemistry and liquid drainage perform separate functions.
What can change the result
- Poor liquid distribution leaves packing surface unavailable for the intended gas-liquid contact.
- Excessive upward gas flow can hinder drainage and increase tower pressure loss.
- Droplet carryover or incompatible wetted materials can affect the downstream fan.
Start with the complete air path
Share your layout and the information you already have. Unknown values can be identified before a configuration is selected.
Match the fan to this air path
LONGWELL offers anti-corrosion centrifugal families. Provide gas chemistry, concentration, temperature, moisture and full pressure loss. Confirm the actual wetted materials and complete scrubber duty before selecting a model.
Where it sits
Downstream of the demister in the countercurrent scrubber arrangement shown. The fan draws gas through the tower and connecting ducts, then sends it toward the designed discharge; that inlet gas may still contain moisture and residual contaminants.
Why consider this configuration
The fan must cover tower, packing, demister, duct and outlet resistance across the intended flow range. Choose wetted materials and seals from the actual chemistry, concentration, temperature and possible droplet carryover, not from the casing colour.
Check the result in your equipment
Discuss your packed-bed scrubber airflow requirements
Send the gas components and concentrations, absorbent, required flow range, temperature and moisture at the fan. Include packing and demister losses, ductwork, carryover conditions and required materials or seals.
A layout, installation photos or your existing model is enough to start the discussion.