Mist elimination
Mist Eliminator Equipment for gas-liquid separation and vapor flow conditioning
In any process that includes the contact between gas and liquid, the gas will entrain some extent of liquid drops. This entrainment causes process inefficiency and apparatus damage.
Drop production
The mechanism following which the drops are produced recognizes the drop size to be eradicated. Knowledge of the processes that cause drop production and the eventual drop size is essential to accomplish the selection and design of mist eliminator.
Entrainment may be caused by the following mechanisms: mechanical action, chemical reaction and condensation. The standard particle size distributed by these mechanisms varies from 0.1 to 1000 microns. Combining the knowledge with experience, the drop size produced can usually be assessed with the reasonable accuracy.
Applications of Mist Eliminators
1. Decline loss of significant chemicals: Monel wire mesh mist eliminators significantly decrease the glycol, amine or solvent consumption in the adsorption and reproduction units.
2. Improve throughput capacity: Mist eliminators permit considerable increase in the throughput wherever gases and liquids come into contact in the process apparatus.
3. Enhance product purity: Mist eliminators avoid contamination of side draws and overheads in refinery conditions and vacuum towers and other distillation columns.
4. Decrease contamination: Mist eliminators can avoid the contamination of the costly downstream catalysts or offer boiler feed water quality condensate from the evaporator overheads
5. Offer apparatus security: they secure turbine, blower, and compressor blades to decrease severe maintenance issues.
6. Decrease air pollution: They help decreasing drop emissions to environmentally acceptable levels.
Common applications of Mist eliminators
Knockout drums
While designing knockout drums including mist eliminators helps in decreasing initial investment and enhancing efficiency. The knockout drums depend only on the gravity settle to remove the drops only more than 100 microns. Using an adequate mist eliminator will avoid entrainment of all drops more than 5 to 10 microns. This high competency decreases the product loss, downstream corrosion,contamination and damage to apparatus like compressors, molecular sieve driers and blowers. Vessel weights can be easily decreased to half and handling liquid slugs is enhanced.
Evaporators
Customized mist eliminators decrease carry over of dissolved and undissolved solids to receive specified steam condensate purity levels lower to 1 to 50 ppm. It not only avoids product loss, but it also secures compressor internals in vapor recompression systems, offers boiler feed water quality condensate and avoids significant pollution troubles.
Industrial installations are different from the chemical plants and inorganic chemical concentrators, to pulp and paper (back liquor and pulping chemical recovery) to the food industry such as sugar, salt and corn syrup generation.
Steam Drums
Customized mist eliminators decrease carryover of dissolved solids to retain specified steam condensate purity levels from 1 ppm lower to 5ppm without the need for external separator vessels. The operating pressures vary from 20 to > 2500 psi or 1 to 170 bar.
Distillation towers
Liquid entrainment can lead to functionality troubles and limit capacity in packed and trayed distillation towers in the two manners:
1.At moderate draw-off trays, entrainment from bottom decreases the purity of product and can permit non-volatile pollutants into the draw-off liquid.
2.The overhead gas product can also be contaminated with liquid entrainment.
In these cases, the trouble is usually not specified clearly and stated as a trouble with the trays or packing. In actual, it is a trouble of entrainment that can be treated by using an adequately designed mist eliminator.
Scrubbers
From clean gas scrubbers and process vents to fouling operations like flue gas desulfurization systems or steel mill blast furnace exhausts, mist eliminators help enhance efficiency and capacity. In the serious services, high functional wash systems are specifically designed to meet the process needs and significantly increase the performance life with nominal wash liquid usage.