To improve mass transfer efficiency in a packed column with multiple layers of packing, liquid collectors and redistributors need to be installed between each packing layer.
When liquid flows downward along the packing layer, there is a tendency to flow towards the column wall, resulting in an increase in the wall flow effect and affecting the uniformity of gas-liquid distribution within the packing layer, thus leading to decreased mass transfer efficiency. The purpose of installing liquid collectors and redistributors is to collect the liquid flowing down from the upper packing layer, to provide a uniform liquid distribution for the lower packing layer, and to offer channels for the rising gas to be distributed evenly.
Single Direction Vane Liquid Collector
It is a versatile liquid collector usually placed below the packing layer to collect all of the liquid. The resistance of the vane liquid collector is negligible and does not affect the uniformity of gas distribution.
Gas Riser Liquid Collector
Its structure is the same as the riser type liquid distributor, except that the upper end of the riser should be equipped with a fluid baffle to prevent the liquid from falling from the riser. Its resistance is larger than that of the vane type, but the uniformity of gas distribution is better.
Features
Combined Liquid Collector & Distributor
A liquid collector and a conventional liquid distributor are combined to form a liquid collector and redistributor. It comes in a variety of forms such as the combination of a baffle liquid collector and a trough liquid distributor.
Deck Liquid Collector & Distributor
The gas phase enters the upper packing layer through a gas riser, while the liquid flowing down from the upper layer of packing is collected completely. Subsequently, the collected liquid is distributed into the lower layer of packing through base orifices. It is generally suitable for large-scale columns.
Pan Liquid Collector & Distributor
Similar to the principle of deck liquid collector and redistributor, the gas phase enters the upper layer of packing through a gas riser, while the flowing liquid is completely collected and then uniformly distributed through orifices or drip tubes.
Wall Wiper Liquid Collector & Distributor
For small-diameter columns, it plays a crucial role in collecting wall flow liquid and directing it to the lower layer of packing. It can be divided into truncated cone wall wiper liquid redistributor and rose-shaped liquid redistributor.
Features
It can be used in packed columns of chemical, petrochemical, pharmaceutical, environmental protection and other industrial sectors in runoff, absorption, resolution, washing and other processes under atmospheric pressure, reduced pressure and pressurization conditions.
