About the temperature difference of heated fluid in thermosiphon reboiler
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I would like to ask everyone, is there a limit to the temperature difference between the inlet and outlet of the heated fluid of the thermosiphon reboiler? Because an old expert questioned our reboiler, saying that the temperature difference between the inlet and outlet of the heated fluid in our thermosiphon reboiler is too large (38 degrees) and cannot be reached. The reason is that there is no such a large temperature difference between the gas and liquid phases in the reboiler.
It can be safely said that the temperature difference is too big! Please inform the medium to be heated, its composition, and operating conditions.
Benzene 5.51%, toluene 15.53, sulfolane 77.75, water 1.19%, temperature 139, pressure 0.1, return temperature 177, vaporization fraction 0.145. All are quality
Of course, the temperature of the incoming and outgoing materials should be about the same. This difference comes from the change in pressure.
I don't understand this very well. I hope it can be explained clearly.
For a two-component separation reboiler, the theoretical temperature difference is very small, because the purity of the material in the tower kettle is already very high, so the inlet and outlet of the reboiler can be considered as the pure heavy component has been partially vaporized. The temperature at this time is the boiling point temperature of the heavy component at this pressure. The reduction in the content of the light component is not enough to affect the change of the boiling point. The resistance of the reboiler also has little effect, generally only a few KPa, and the impact on the boiling point can be ignored. For multi-component separation, the change in vaporization temperature caused by changes in the tower reactor components must be considered, but the temperature difference will not be too large. 38 degrees Celsius should be a bit outrageous.
I don’t agree with the expert’s statement. Your system is a three-component system, and the boiling points of each substance are very different. If you require such a large vaporization rate, you must reach your temperature.