Fan upstream or downstream of a scrubber

[RistEcho]

When installing the fan for a scrubber for exhaust gas treatment, do people like to design it upstream or downstream of scrubber?

I’ve seen it done both ways, but I would like to see hear the group’s thoughts on pros/cons.

 

[shvet]

This is case specific. To get useful replies, you should describe your case in detail.

 

[pierreick]

Hi,
A google search.
Pierre


In a wet scrubber system, the fan can be located either upstream or downstream of the scrubbing column. Placing the fan upstream can help reduce the fan's exposure to corrosive or dirty gases, while downstream placement allows for greater flexibility in system design and better operator working conditions.

Upstream Fan Placement:

• Pros:
  The fan handles cleaner, cooler gas, potentially prolonging its lifespan and reducing maintenance needs.
• Cons:
  The fan may need to handle higher gas volumes and potentially higher pressure drops due to the scrubber's resistance. This can increase energy consumption.
  

Downstream Fan Placement:

• Pros:
  The fan handles a smaller volume of gas (after some of the pollutants have been removed by the scrubber) and potentially lower temperatures and pressure drops, potentially reducing energy consumption.
• Cons:
  The fan may be exposed to corrosive or dirty gases, leading to increased wear and maintenance.
  

Additional Considerations:

• Scrubber Design:
  The scrubber's specific design (e.g., packed bed, spray tower) can influence the optimal fan placement.
  
  
• System Requirements:
  The overall system requirements, including gas flow rate, pressure drop, and desired efficiency, will also factor into the decision.
  
  
• Flexibility:
  Downstream placement offers more flexibility in terms of system layout and access.
  
  
• Safety:
  For systems handling hazardous or corrosive materials, upstream placement might be preferred to protect the fan.