How are the internal components of a distillation column with a diameter of 600 mm installed?
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Currently, a distillation column with a diameter of 600 mm and a height of 20 m is being designed. It is equipped with three layers of mesh corrugated packing, each layer being 4 m high; a liquid separator is installed in each layer. The distributor used is of the tube-type design. The manholes on the column have a diameter of 450 mm. Due to the small diameter of the column, it is difficult for technicians to enter the column to carry out installation work. Furthermore, since this column operates under high vacuum conditions and is made of the expensive 316 material, we do not want to use a method that involves connecting the various components via flanges. What is the best way to install the packing and other internal components of this column? Please give me some advice, thank you!
Based on my personal experience, you can design a special tool for loading the filler material. Since the diameter of your tower is small, each small layer of filler can be divided into two sections. Find a thin person to lie down at the manhole, with another person at the manhole on the upper level; the two work together. When installing the topmost layer, the other person should be at the outlet at the bottom of the tower. After the first piece is placed into the tower, a person at the top uses installation tools or ropes to lift the first piece of packing; then, once the second piece is inserted into the tower, the two pieces are combined together. Then, specialized tools are used to place the packing inside the tower.
In my opinion, it’s better to divide it into sections – this makes maintenance and replacement easier in the future. Moreover, what you have now is placed inside a frame.
Is the tower design ready yet? Or is it only the process engineers who are considering this issue? If it’s just the concern of the process engineers, then there’s no problem. Professional tray manufacturers will provide corresponding tray installation services; you can simply consult the manufacturer of the trays you are using. PS: For such a small tower, special tools will likely be required for installing the trays, and the price of those trays might be a bit higher than usual^_^
I don’t quite understand why the original poster is reluctant to use the segmented flange connection method; we have built many distillation towers with a diameter of 600 mm, all of which employ this segmented flange connection approach.
Dear moderator up there, the design in question is for a packed tower. If there is only one section of packing, it’s not necessary to use flanges; however, with three sections of packing, it’s advisable to use flanges for connecting each section. If there is enough space between each section of packing, sufficient for one person to fit in, then flanges may not be needed, but the height of each cylinder section should be at least 1.2 meters. Consider whether it’s more expensive to have cylinders that are over a meter high along with a 450-mm access hatch, or to use pairs of 600-mm flanges.
With a 600 tower that has been erected without flange sections, it is very difficult for people to get inside for installation. You should coordinate with the owner to carry out the installation promptly while the tower is still not upright, as this will save a lot of effort. When the tower is lying down, people can enter and press down; the packing is installed in sections through the manhole, and the distributor is also installed in sections (the installation location can be set between the manhole and the upper packing support)
1. Is the wire mesh filler to be installed once only, with no need to replace it during subsequent operations? 2. If it is to be installed once, more manholes can be created; first, the fixing elements inside the tower should be welded in place, after which the wire mesh filler can be added, and this process can be repeated layer by layer until the top layer is reached. 3. Or is it possible to change the diameter of the tower?
In my opinion, it is not a good situation to have a tower of 600 with an access hatch of 450; even if reinforcement is applied, it remains a weak point. Adding flanges can enhance strength, and carbon steel flanges with welded rings can be used for this purpose. Furthermore, the lack of flanges makes maintenance a difficult task.
Some of the towers around 600 meters in height that I’ve seen are segmented, which makes installation and maintenance much easier
It’s normal for a tower of 600 to have manholes of 450 in size; many of our towers are like this. I think, considering ease of installation and future maintenance, it’s better to divide the packing into sections – each layer is divided into several segments, with each segment consisting of two or three pieces that are connected to each other using bolts, and the upper and lower parts of each layer are held in place by pressure plates.
Personally, I think it’s much better to divide it into sections – is it easier to carry out maintenance that way? If it’s not segmented, it will be more troublesome to replace the packing in the future. Moreover, adding a pair of DN600 flanges and an DN450 manhole shouldn’t cost that much, right?
Since it is a structured packing, the tower has a small diameter and people cannot enter it. It can only be manufactured in sections, with the filler installed at the same time.
Without paragraph breaks, it will be impossible to carry out maintenance later!
It is recommended to use a flanged cylinder; after installing the packing, it should be installed in sections. For maintenance, the cylinder must be disassembled and the packing removed for cleaning
Segmented flanged vacuum distillation columns are not often used, as they can lead to internal leaks that affect the vacuum level, and it is also difficult to inspect them. The tower internals can only be installed by humans entering and exiting it. This requires sufficient installation height to be left in the space of each layer of packing, and manholes must also be provided in the liquid distributor section for installation purposes.
It should be designed as a flanged tower section to facilitate installation. After all, the accurate installation of packing, especially internal components such as distributors, is crucial for the distillation efficiency of a column. One shouldn’t give up the big picture for trivial matters.
If this tower has already been designed, then the person who designed it should stop working； If this tower is manufactured by a factory, then that person is extremely talented. I don’t know whether he should include manholes or how to reinforce it. If the owner allows those two things to be done in that way, then there will be no one left working in that company. If the internal components can be installed by such a factory, then it has workers who are of dwarf stature; I don’t understand how such a problem can arise!
If the tower diameter is indeed small, it is still more appropriate to use segmented design, as the use of 316 material ensures a long service life for the equipment, making maintenance quite important.
It is recommended that the original poster divide it into sections, otherwise it will be very inconvenient during maintenance! I have a packed tower in my workshop that is used as an absorption tower; due to bacterial growth in the spray nozzles, the packing became clogged. Thankfully, it has flanges!
First of all, segmentation is a very good approach. It’s just that higher standards are required for the manufacturing level. However, segmentation is a very good approach for ordinary towers; but what if scaling occurs inside the tower and its resistance increases? We can’t possibly replace the tower, especially since the cost mentioned by the original poster is quite high. Secondly, if the original poster truly does not have the conditions to build a segmented tower, I suggest focusing on the tower packing and liquid distributor. Create a whole unit and then lift it together. When it’s time for maintenance, just open the upper head and pull out the entire internal structure of the tower. But that way you can switch to an annual salary as well.