Regarding NFU heat exchangers
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Hello everyone, I have a question. There is a heat exchanger that, due to its large diameter and high pressure, needs to be designed in the NFU format in order to avoid using large-diameter, high-pressure flanges. Is it possible to use a head on the tube box side? The tubes enter the tube box through openings whose diameter is greater than 500; is this approach feasible?
For on-site maintenance, it is not practical to go inside from the pipe opening. It is more difficult to disassemble if the pipe is large.
Setting a transition section is no problem.
There is nothing that is impossible; in fact, some large-diameter, high-pressure flanges under normal operating conditions simply cannot provide a proper seal. It’s best to divide the pipeline into smaller sections, so that removing a small segment of the pipeline allows direct access. Additionally, it’s important to improve the reliability of the equipment, for example by increasing the wall thickness of the heat exchange tubes and upgrading their material quality. This is done to reduce the need for maintenance and to cut costs. Otherwise, when the pipes become severely damaged, the entire equipment may need to be replaced. If used shells are employed to replace the pipe bundles, it’s difficult to meet the original pipeline dimensions, and the inspection procedures are also complicated – this is just my personal opinion.
The diameter of the equipment is quite large, nearly 3000; is it suitable for use as a manhole?
Does it refer to the short section between the tube sheet and the head?
The main consideration is cost reduction; maintenance can be carried out for cleaning, while the tube bundle can only be used as a fixed tube sheet
Don’t all large-diameter tubular hydrogenation reactors have manholes in the tube bank?
Yes, I want to use this type of reactor design for heat exchangers