Where is the demister pad usually located?

• A. At the top
• B. At the sump
• C. On the shell
• D. In the piping

Answer: (B)

Mist eliminators, or demister pads, are placed where rising gas carries small liquid droplets so those droplets can be intercepted, coalesced, and drained back into the liquid phase. Putting the pad in the sump—the lower part where liquid collects—situates the mist eliminator right in the zone where droplets are still present as gas begins to leave the liquid. As gas flows through the pad, droplets collide and coalesce and then drain away into the sump, reducing carryover into the outlet. This location offers effective contact with the entrained mist and uses gravity to return the coalesced liquid to the liquid pool, which is why it’s normally chosen.