How should multiple reboilers be arranged around a single tower? I hope the experts here can give some guidance! ! !
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This post was last edited by xjjisdawn on 2018-5-17 at 16:10. Currently, I am working on an energy-saving renovation project. One of the towers involved in this project originally had two thermal siphon horizontal reboilers in use simultaneously; these two reboilers were arranged symmetrically. A main pipe led from the tower to the reboilers, dividing into two branches, and the return pipes from the reboilers to the tower were also positioned symmetrically on either side of the tower. Now, it is necessary to use the heat from another stream of fluid to replace the heat source of one of the reboilers. The workshop refuses to replace the existing reboiler with a new one in its original location, nor does it agree to make changes to the piping connected to the existing reboilers in order to switch the heat source stream. Instead, they require that additional equipment and piping be installed without altering the existing process flow, so that they can switch back to the original process immediately if the new process does not function properly. The problem is that the space on site is limited. By adding a new reboiler next to the existing one, logistical constraints mean that the piping for this new reboiler will inevitably be longer and have more bends than that of the existing reboiler. Moreover, considering the requirements of the workshop, two isolation valves need to be installed at each inlet and outlet of the new reboiler as well as those of the reboiler it is intended to replace. I’m concerned that the pressure drop in the piping system of the new reboiler could be much higher than that of the existing reboiler, leading to severe flow imbalances. Please, dear experts, share your ideas and suggestions freely :) Please include the images; within the red lines in the plan are the towers mentioned, along with the two reboilers currently in use. The workshop suggests moving the heat exchanger within the blue lines on the left to another location, and placing a new reboiler here. But what worries me the most is the issue of flow deviation – will it affect the siphoning action in the reboiler and the heating in the tower?:dizzy:
You’ve already thought of a lot; it’s hard for others to come up with better solutions. The textual description is not ideal; it would be better to have images
The space is insufficient; therefore, the reboiler should be changed to a vertical type. One of the existing elbows should be replaced with a tee connection, so as to connect directly to this unit. The heat exchange area needs to be calculated based on the heat source. It would be good to add temperature gauges at the inlet and outlet of the reboiler; the rest can be adjusted by the workshop staff as needed:lol:lol:lol
It is recommended that, if possible, a hand-drawn or digital version of the drawings be provided, as this will help with understanding
Personal opinion: The material at the bottom of the tower should flow through the shell side of the reboiler. The pressure drop caused by straight sections and elbows in the piping isn’t as significant as one might think; it can be taken into account during the design of the tower base, so these factors can be ignored. The method for calculating pressure drop due to elbows can be found on Baidu. The reboiler relies on the density difference resulting from temperature differences – if the temperature is too low, it won’t be able to function properly. Additionally, the offset flow issue should also be fine, as the material returns to the tower at its bottom, not at the tray level. I’m not entirely proficient in this, but I think it’s completely possible to meet both the workshop’s requirements and the installation location constraints. It’s just my personal opinion; I hope it helps. You’re someone who likes to think, so give it a like
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The image has been uploaded; the text description is indeed a bit complicated. If you have any good suggestions, please help out :)
From a planar perspective, the new heat exchanger can be placed in the space between the existing reboilers and the tower. Since it’s not known what size the new heat exchanger will be, you can arrange it accordingly; there should be no major issues with flow redirection. Just be careful when installing the piping. I’ve seen cases where two reboilers were placed on one side of the tower, and that worked just fine as well.
With this type of horizontal reboiler, which uses thermal siphon effect, aren’t you concerned about material deposition and blockages? Add a forced circulation pump; one reboiler might be sufficient as well. One pump serves both sides, with the reboiler being used in turn, operating 24/7 without any downtime:lol:lol:lol
I considered going with pump-driven circulation, but the workshop disagreed. . .