Stainless steel tower internal liquid collector and re -
distributor
Usually a complete packed distillation tower has two or more
packing layers. A liquid collector and redistributor shall be set between each two packing layers to collect the liquid
from the upper packing and redistribute the liquid into the lower
packing. Sometimes, the tower has side lines for feeding and
discharging, and the tower packing in these parts should be divided
into sections. There is a certain limit on the height of each section of tower
packing, which is generally equivalent to 15-20 theoretical plates, that should be divided into sections. Therefore, liquid collector
and liquid redistributor are indispensable tower internals.
In the down flow of liquid in the tower, there may be uneven
distribution, resulting in uneven liquid concentration on the cross
section of the tower. The liquid collection redistributor can
completely collect and mix the liquid phase with uneven flow rate
and concentration, which is beneficial to give full performance
regarding to the separation efficiency of the tower. In addition,
the rising gas must be evenly distributed in the upper packing, and
the resistance is smaller.
Working principle:
The liquid falling from the upper packing is collected by the
liquid collecting plate, flows through the lower liquid guide
trough and then into the bottom liquid collecting trough in the
center. When the diameter of the tower is large, in addition to the
center collecting trough, the surrounding ring collecting trough is
also set, and the collecting shutter is fixed on the middle
horizontal trough and the ring groove. The liquid collected by the
liquid collecting plate flows into the horizontal groove and the
annular groove, and then flows into the redistributor below through
the central tube of the horizontal groove to mix and redistribute
the liquid.
General failure analysis and treatment of packed tower:
| Phenomenon | Possible cause of failure | Advice |
| Tower efficiency is low, product quality is poor, but packing
pressure drop is normal | It is mainly caused by uneven liquid distributor 1. Poor design, liquid overload range; 2. Poor installation levelness; 3. The liquid distributor is blocked; 4. Liquid distributor leaks due to medium corrosion | 1. Improve the design, increase or decrease the opening of
distributor; 2. Reinstall and adjust the level; 3. Remove the blockage; 4. New distributor made of more corrosion resistant material |
| Low efficiency of tower and low pressure drop of packing | Too loose packing installation or too large clearance with tower
wall | Install as required. Temporary measures to increase return flow can
improve efficiency. |
| The packing pressure drop is large, and the operation upper limit
capacity is reduced | 1. The metal filler is installed too tightly and has large
deformation; 2. There are many broken ceramic fillers | 1. Install as required. Temporary measures to reduce the operating
load can improve the efficiency of the tower; 2. Remove debris. Temporary measures to reduce the operation load. |
| The product yield of the upper side is low, that of the lower side
is light and that of the lower side is high | The oil collecting tank on the upper side is not sealed, and there
is oil leakage downward. | Repair unsealed areas or reinstall. |
| Unable to reach the design capacity, flooding ahead of time, low
tower efficiency. | 1. The opening rate of packing support plate is low; 2. Low opening rate of packing press plate | 1. Replace with high opening rate support plate; 2. Replace with high opening rate pressing plate. |
| After a period of operation, the pressure drop increases gradually,
the efficiency decreases, and the load capacity decreases | Packing blocked and coking | Clean or replace packing |
| After operation for a period of time, the pressure drop fluctuates
from high to low, and the efficiency decreases | The packing is corroded | Replace the anti-corrosion material filler |
| After a period of operation, the quality of the product decreases
and the color becomes heavier | 1. The wire mesh of metal demister is corroded 2. The wire mesh of metal demister is blocked or twisted to form
re-entrainment. | 1. Replace the anti-corrosion material demister; 2. Replace the demister with high void ratio |
Liquid collector and re-distributor position and plate size:
Welcome your contact with your private tower internals plan or
ideas!
