GRAPHITE COLUMN &
COLUMN INTERNALS

Exhaust gases & particles for processes cannot be let out into the atmosphere untreated upto certain permissible ppm levels safer for the environment. Air pollution control devices are used in industries to prevent hazardous gases and soot from polluting the air. Equipment such as scrubbers in different arrangement namely packed bed, venturi arrangement etc. suitable to given process are used for the application.

These types of columns are used to remove some particulates and/or gases from industrial exhaust streams. They consist in columns with gas inlet at the bottom and washing liquid fed from the top over the entire cross-section. Gas and liquid are passed through the column at counter flow. Before the gas leaves at the top of the column, entrained scrubbing liquid drops are retained by adequate droplet separators. The column design (height, diameter, number of trays, packing sections heights, type of packing, etc…) depends on the cleaning task and the composition of the exhaust gas.

Random packed and bubble cap tray type columns are most prefered for most applications. This ensure an intimate contact between the up-flowing gases and the down-flowing liquids and therefore to generate the necessary mass transfer. Columns fitted with trays are usually better at handling solids or other sources of fouling. They operate also more efficiently at lower liquid rates. On the other hand, packed columns offer a lower pressure drop and are usually better at handling foaming systems. Liquids tend to wet the surface of the packing, and the vapors pass across this wetted surface, where mass transfer takes place. Differently shaped packings have different surface areas and void space between packings.