The distributor is a key element of the packed column and packing efficiency depends on good liquid distribution provided by the distributor.
Distributors are installed above the packing beds in the columns and generally positioned at a distance between 50 and 250 mm above the packing bed. The space is defined by the design of the distributor and the vertical height required for disengaging the vapor phase of the packing before passing through the distributor gas passage area.
The multi-bed columns are complicated but some distillation process parameters as a high number of theoretical plates, the need for side draw product, or mixed liquid introduction into the column imposes a design of a multi-column bed and within this case a redistributor is necessary to create a uniform distribution of liquid over the bed of packing.
An ideal distributor has the following attributes
The distributor is a key element of the packed column and packing efficiency depends on good liquid distribution provided by the distributor. The packing performance is only possible with optimum distributor design. HMDS operates a test facility for liquid distributors to measure performance and demonstrate the quality of the distributors supplied.
our facility can test liquid distributors Up to 10 meters
the discharged liquid flow is measured at various points below the liquid distributor.
The performance of the tower is in close link with the quality of liquid and vapor entering in column and the choice of the feed tube which is generally classified into four categories:
The parameters that most influence the feed tube are distributor design & performance, flow rate, operating range, which is why the feed tube must be designed when the distributor design is completed.
For a vapor/liquid mixture or flashing feed device above a distributor, the design of the feeding tube depends on the type of dispenser, liquid & gas flow rate, turndown, and column height required for vapor disengagement.
In the distillation column the inlet distributor should be designed properly because the large volume of gas causes poor distribution in the column if the distributor is not suitable. Poor distribution and high gas velocity causes the liquid re-entrainment.
It is therefore important to control the gas velocity by a properly designed distributor. The H-VID reduces the velocity of circulating gas and prevents re-entrainment of previously collected liquid. The H-VID reduces the dynamic of the inlet feed stream in a controlled manner and allows the removal of liquids, bulk solids and distributes the gas flow uniformly to the intended device.
Two factors must be considered in the design of a vapor-only feed :
When the vapor is introduced between packed beds, consider the degree of mixing of the inlet vapor with the rising vapor. If a gross mismatch of composition and/or temperature exists, mixing of both vapors optimizes packing performance above.
Specific equipment for vapor distribution may not be required if the pressure drop in the packed bed is sufficient for proper vapor distribution.
To determine the type of feed device required for a reboiler return, the first step is to consider the kinetic energy as described above. Once the required type of vapor distribution is determined, factors to consider include feed nozzle size and arrangement, pressure drop in the packed bed, flow rates, tower size and type of reboiler.