Is the pressure at the top of the distillation tower high and the pressure at the bottom low? What’s the reason?
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We are using a packed tower for aromatics; the pressure in the reflux tank is 25 Kpa. For some reason, the pressure at the bottom of the tower is 2–5 Kpa lower than the pressure at the top. I first thought it might be due to an excessive amount of light components in the feed, so I tried reducing the reflux ratio, lowering the feed temperature, and reducing the temperature at the bottom of the tower, but none of these measures worked. What could be the cause? How to solve it?
Could there be any issues with the measurement? Are you using the same pressure gauge to measure?
Agree with the person above; could it be a problem with the pressure detection?
There seems to be an issue with the pressure detection; it is recommended to use the same pressure gauge for testing
It is recommended to calibrate the gauge to determine whether the pressure gauge is functioning properly
1: Check the pressure difference gauge of the tower. As the original poster mentioned, the value on the gauge should be zero; if it shows a positive value, then there is an issue with the measurements taken by the original poster. 2: Check the top temperature of the tower and the temperature in the reactor; if the top temperature is low while the temperature in the reactor is high, then there is an issue with the measurements taken by the person in question. There is no need to measure the pressure in the top vessel of the tower; the quality of the pressure gauge used in the tower can be determined directly from these two parameters.
I think the main issue is the error in pressure measurement. I encountered similar problems during the production process, and it was the pressure measurement that caused the issues; once it was calibrated and replaced, the problem disappeared.
Reason: 1. There is a problem with the pressure gauge; it needs to be calibrated； ⒉Has there been any change in the components? There are more light components; conduct a component analysis as follows ；
Considering the above, could increasing the reflux and raising the feed temperature work?
The problem should first be looked for in the instruments; there may be an issue with the measuring instruments, so replace them and conduct testing.
This phenomenon generally does not occur. Is the bypass valve of the tower top pressure control valve fully open? Or is the pressure-controlled valve fully open?
It is likely that the operation of the tower was unbalanced; the light components in the feed suddenly increased, and the reflux flow was not adjusted in a timely manner. As a result, the amount of vapor in the distillation section of the tower increased, the overhead reflux could not be cooled promptly, the vapor pressure at the top of the tower rose, which in turn led to an increase in the pressure at the top of the tower. As a result, the recombination component at the tower bottom decreases, the load is reduced, and the pressure at the tower bottom falls.
First, use the same gauge to take a measurement to see if it’s a problem with the pressure gauge.
I have a question for everyone: Have you come across any cases where the operating pressure in a distillation tower is higher at the top than at the bottom? Haha, I’m referring to the normal design operating pressure; sorry for not making that clear. This post was last edited by realdark on 2009-4-14 at 12:50.]
No matter what the components are, the source of pressure remains at the bottom of the tower, unless external substances are introduced by cooling water or something similar. First, check if there are any issues with the pressure measurement; if nothing is wrong, then check the other aspects.
1. Is the temperature at the bottom of the tower also lower than that at the top? If not, it might be a problem with the instruments. 2. If it’s not the case mentioned in point 1, I believe it could be due to blockage in the tower packing, which results in wall flow.