Electrodesalination water injection issue
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Why does the flash vapor pressure increase as soon as water is added to our electrodialysis system, even though the current level is not high? I’m not sure what the reason for this is
If the properties of the feedstock remain unchanged and the flash pressure increases after electrodialysis water is added, first check whether the amount of water removed from the reflux tank at the top of the atmospheric pressure tower has increased. If the amount of water removed does increase, it is likely that the water from electrodialysis has not been completely separated after addition, and this water ends up in the flash tower, causing its pressure to rise and thereby increasing the amount of water removed from the reflux tank at the top of the atmospheric pressure tower. As for why the current level is not high in electrodialysis, it might be related to the quality of your feed material or the temperature at which the material is fed into the electrodialysis process. It’s also possible that the operating temperature is too low, resulting in the oil being encapsulated within water; under high electric fields, the water cannot be separated from the oil. Try increasing the electric field strength used in electrodialysis to see if that helps. It’s not necessarily true; for reference only.
Water injection should not result in a water-in-oil structure; increase the voltage as suggested above to enhance water separation
The constant top pressure has increased, but there is little change in the water cut in the constant top reflux tank
Without adding water, the pressures at the tops of the flash tower and the atmospheric pressure tower are not high; however, these pressures increase after water is added. This clearly indicates that water has entered the system. Before adding water, check what the opening degree of the water cut control valve in the overhead reflux tank is. After adding water for electrodesalination, wait until the pressure at the tower top rises and then check whether the opening degree of the dehydration control valve has increased. If it has, then it’s definitely water that has entered the system – even a small amount of water can cause the pressure to rise. Your feed materials won’t separate into layers, right? It won’t happen that, at the time of water injection, the lighter materials end up in the flash tower. Try it a few more times to see if this happens every time you fill it with water.
Compare the water content before and after electrodialysis, before and after water injection, to determine whether water has not been removed and carried into the tower
Delayed crude carries water. You can try reducing the amount of water injected, or increasing the water removal, to see if that makes a difference