A problem with the packing in a distillation tower
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We have a distillation column that needs to be replaced due to changes in operating conditions. It was originally operated under slight negative pressure, but now it is to be operated under positive pressure, with a column pressure of around 0.2 MPa. The packing used in this column are Pall ring type packings. We would like to use the same Pall ring packings from the original column; the packings currently in use in our existing positive-pressure distillation system are of size 50X50X3. However, the packings in the original negative-pressure distillation column were of size 38X38X1. Upon inspection, there isn’t much difference between these old packings and new ones – they are just a bit older, but their rigidity remains satisfactory. We would like to ask experts whether these old packings can be used in the new positive-pressure distillation column (the diameter of the new column is 200 mm larger than that of the old one; the material processed is hydrofluoric acid, and the operating conditions involve two columns connected in series: the first column has a pressure of 0.2 MPa and a temperature of 55 degrees Celsius, while the second column has a pressure of 0.1 MPa and a temperature of 45 degrees Celsius)
It can be used in segments; with a small amount of old filler, it is applied only to certain sections.
This has nothing to do with whether the filler is new or old; as long as it’s not damaged, that’s fine. The key is to see if the flux requirements can be met
Whether it can be used in the new tower needs to be determined through hydraulic calculations.
Personally, I think this has nothing to do with the positive or negative pressures in the distillation tower; it is mainly related to the requirements of the process after the improvements are made, especially the load on the tower, which is directly connected to the size of the packing used.
The packing has no relation to the operating pressure of the tower; the height of the tower packing can be calculated based on formulas. The choice of filler type is related to the properties of the material.
It can be used in new towers. Since the specifications are different, the old ones can only be used in certain sections of the tower, and there are no strict requirements regarding the medium flow rate; the use of packing has nothing to do with the tower pressure.
This is also a method, but I think we still need to consider the resistance of the old filler; otherwise, it’s difficult to determine its height
I think the same way; flux is essentially a problem related to tower resistance, and by solving this issue, we can arrive at a conclusion
There’s no need to go to such trouble, right? L: The height of the tower isn’t very different, is it? By hydraulic calculations, you mean the distribution of the medium within the tower, right?
I thought the same way; I asked our senior designers as well, and their opinions were the same as mine. But one graduate student firmly said it couldn’t be used
The tower’s load has increased by a little over 1 cubic meter; it’s now around 3.5 cubic meters. That’s not that much, right?
Well, yes. Since the materials are the same and the difference in fillers isn’t significant, the only thing to consider is the height of the filler. Is that what you mean?
Well, that makes a lot of sense; I think this loading method is the most reasonable. The prerequisite remains the same: not to increase excessive tower resistance
It will become clear after the calculation; logically, positive pressure operation is better than negative pressure operation. Let’s do the calculations so that there are no disputes!