Fiberbed Mist Eliminators
Construction Materials
Fiber bed mist eliminators are made out of dense layers of micron size fibers placed between two concentric cylindrical cages.Various fibres can be used;
- chemical resistant glass fibres
- polyester
- carbon fibres
The cages are available in:
- Stainless steel
- Carbon steel
- Special alloys
- FRP
- PVDF
- PTFE
- Polypropylene
- Typical Applications
- Metallurgical acid plants
- Spent acid plants
- Ammonia scrubbing
- Ammonium nitrate
- Lube oil vent from compressors
- Digesting of wood pulp
- Chlorine Industry
Characteristics
Fiberbed Mist Eliminators are high efficiency separators that are able to collect droplets at submicron level. They are available as cylindrical elements and can be manufactured in a broad range of materials.
Fiberbeds are produced as a dense packing of fiber (glassfiber, polyester fiber, carbon fiber) assembled between two concentric screens, foreseen of a flange on top or bottom for installation on a tube sheet. The elements are normally manufactured in one piece and can be installed through a manhole or vessel open end. The Diffusion type candles (DC) use Brownian Diffusion, interception and impaction as their collection mechanism and can collect essentially 99.95% of all submicron liquid particles and soluble solid particles. The pressure drop across the elements can range depending on the design from 25 to 500 mm W.G. (1-20 inch). Due to the principle on which these elements capture droplets, theyhave a virtually unlimited turndown capability, without loss in efficiency.
The Impaction type candles (IC) use only inertia based impaction as their liquid removal principle. These types of candles are designed to economically capture droplets in the range of 1-3 micron. The collecting efficiencies at these micron sizes range from 90 to around 97%. The pressure drop across the elements can range depending on the design from 100 to 250 mm W.G. (4-10 inch).
The operating principle is that a gas stream loaded with fine mist particles will enter the bed of densely packed
fibres from one side, while from the other side clean gas will emerge and escape from the mist eliminator.
The liquid, either separated by Brownian motion or Impaction, will be directed downwards of the candle towards the outer screen and will then drain off the downstream face of the fiber bed by gravity. Fiber bed mist eliminators are typically installed in a vessel or a tank and the collected liquid is continuously drained from within the tank.
Benefits
- Extremely high liquid removal efficiency
- Unlimited turn-down capabilities without efficiency loss