Why is the effect of thermal siphon not good when the components are too light?
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If the components of the medium in the bottom of the tower are light, it may result in poor thermosiphon effect, preventing the establishment of thermosiphoning. Please ask an expert to help me understand the reason behind this sentence.
The driving force of thermosiphon effect is the density difference; if the density is low, the driving force is weak
Reply to 2# su*ubin: I was wondering if there is also the reason that light components vaporize easily, which prevents the liquid level at the bottom of the tower from being established and stops thermal siphonage from continuing; moreover, the presence of heavy components can increase the heat capacity?
For detailed calculations, one can refer to books on reboilers. In any case, it is necessary that the driving force be greater than the resistance; this driving force is primarily due to the pressure difference. A lower density requires a higher pressure difference, and if this requirement is not met, the operation will not be stable
This post was last edited by wiseboy on 2011-4-6 at 19:59. (1) The original poster’s claim seems to come from somewhere; it is not accurate. It can be said that the low density of the kettle liquid is not conducive to siphoning. You say the components are light, but others mistakenly think they are volatile – that’s completely wrong. (2) The explanations for the 2nd and 4th floors are correct.
Reply to 5# wiseboy: What I said is correct. In one tower, due to the light composition of the components, such as the presence of C2 and C1, it is difficult to establish thermal siphon effect. Therefore, a medium containing C3 is injected at the bottom reboiler to assist in creating this thermal siphon effect. I would like to ask whether there are any other reasons besides density……
In theory, this is true; in practice, however, the light components in the tower bottom generally are not abundant.
Reply to 6# yy1007: If there are volatile components, I think it’s the evaporation of the lighter components that causes the problem. I’ve encountered situations where evaporation led to the pump at the bottom of the tower becoming empty.
This one. . . Does that mean that because the components vaporize so easily, all the liquid at the bottom of the tower gets vaporized as well? . .
This post was last edited by wiseboy on 2011-4-7 17:10. Lightness and heaviness are relative, relative to this distillation tower. In a normal tower, the liquid at the bottom of the reactor is always the heaviest in the entire tower; if it is said that \"the liquid at the bottom of the tower has been completely vaporized,\" then there is a problem with that distillation tower. Therefore, many of the statements made by netizens above are not accurate.
Uh. . . Actually, what the original poster is referring to is difficulty in starting