ABSORPTION COLUMNS

The columns that we propose exploit the absorption principle, a single operation based on the transfer of a substance from the gas phase to the liquid phase. They are successfully installed for treating gaseous effluents containing, ammonia, various basic compounds, various acidic compounds, organic compounds, and various odors.

About the choice of the solvent for the abatement, in general we use substances little dangerous, inexpensive and with a strong interaction in the liquid phase with the pollutant molecule.

For the absorption, being understood as a deletion of a pollutant, it must be clear destination of the pollutant once absorbed, our supplies always include assistance to the customer in finding the optimal solution for the disposal, thanks to the collaboration with Euro D Srl, another company belonging to the Group Consulenze Ambientali.

The choice that allows the maximum efficiency of absorption, considering the same solvent consumption and the same number of stages, is the system in countercurrent, realized in absorption columns, in which the liquid enters from above and goes down in countercurrent contacting the gas fed from the bottom.

Usually we use columns filled with materials having large specific surface, which are completely wetted.
The packed columns are constituted by a vertical cylindrical, containing within the filler material and supported by a bottom grid. The liquid is poured over the fill from a distributor, proceeding downwards the liquid wets the entire surface of the filling and partly collects on the wall, where it percolates losing its absorbent efficiency. This phenomenon of by-pass the filling is amplified by incorrect verticality of the column, due to the deviating gravity action on the motion of the liquid, especially for columns with low value of the filling ratio diameter/height.

A ratio Diameter/Height, not correctly sized, drastically reduces the collection efficiencies.
The motion of the gas through the filling is normally turbulent and the pressure loss varies as a function of the square of the flow. Passing from the gas stream in the dry column to the gas flow in the wet column, the pressure drop increases with increasing the flow rate of liquid fed.

As the speed of the gas increases, increases the amount of liquid retained by the filling, until the pressure drop assumes an increase much faster, due to the fact that the gas must sustain and cross substantial levels of liquid. This point is known as the flooding point, since in this condition the equipment is completely unbalanced and are formed entrainment of liquid and by-pass of gas which reduce the efficiency of absorption. A suitable dimensioning of the column, coupled to a correct logic operation and management of the process can avoid this phenomenon.
An important feature of the filling and its wettability, that is the minimum amount of liquid to be fed to the column to ensure a liquid film over the entire filling. The amount of liquid held within the filling affects the load acting on structures, and also on the ability of the column to absorb fluctuations of the liquid flow rate.

LISTED BELOW ARE SHOWN PICTURES OF PLANTS WE HAVE INSTALLED.

THE COMPLETE LIST OF EQUIPMENT INSTALLED BY FIDIA ENGINEERING SRL IS AVAILABLE UPON REQUEST.