Mist Eliminators (ME) in FGD-plants play a vital role. The ME primary function is to stop the liquid absorbens (limestone slurry, sea-water) to escape into the environment, but there are other secondary functions as well.

Depending on the requirement of the operator or the recommendation of the process licensor, the ME can consist out of 2 or 3 stages.

2 stage ME systems

2-stage systems consist out of pre-separator and fine separator. The systems are either FLAT and installed on 2 support beam layers or of ROOF type and installed on a single layer of a support beam.

2 stage ME are able to remove the absorbens to a residual liquid content (RLC) below 50 mg/Nm³.

3 stage ME systems

3-stage ME systems are far-advanced in comparison to 2-stage systems as they provide the process licensor more design flexibility. These systems can be operated at higher gas flowrates and remove the residual liquid content below 20 mg/Nm³.

3-stage systems are typically installed on 2 support beam layers when using a combination of FLAT and ROOF-type ME. But there are also 3-systems with 3 stages FLAT on 3 support beam layers.

Illustration: FLAT-design Mist Eliminator

Illustration: 2-stage ROOF-design Mist Eliminator