On the issue of flow dead zones on the distillation column trays when diesel is extracted from it
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When the diesel extraction port at the top of the catalytic fractionation tower is in use and the lower extraction valve is completely closed, is there a dead zone between the trays at the top and bottom extraction ports? Is it still the increase in the liquid layer thickness between the upper and lower extraction ports that causes leakage in the distillation tower? Everyone is welcome to discuss
If the extraction from light diesel is partial, the amount of extraction must be controlled; otherwise, dry plates will form on the trays between the upper and lower extraction hoppers. If full extraction is required for the light diesel, simply change the middle return port to the upper position. As for the dead zone and tray leakage that the original poster is worried about, they will not occur.
Reply to 2# chengkang: Let me talk about our unit. The diesel has two extraction ports, one at the top and one at the bottom. The reboiler has only one port. If only the upper extraction port is used (with the lower one closed), partial extraction occurs; then wouldn’t there be a dead zone for flow between the upper and lower extraction ports? At this point, the liquid layer fills the tray space between the upper and lower outlets – could there be leakage?
Leaking? Don’t all the materials in the tower move upward as a gas phase and downward as a liquid phase? What is leakage? At most, this oil collection tank is just a matter of capacity
Reply to 3# 328104062: Both the bottom tray above the light diesel and the tray below the light diesel have liquid drainage channels; thus, the situation described by the original poster, where the liquid layer fills the space of the trays at both the upper and lower extraction ports, does not occur. If there are drawings available, the original poster will understand this once they take a look.
Where are the blueprints? Can you show it to me? I’m very interested
How can the liquid layer fill the tray space of the upper and lower outlets? Isn’t that going to flood the tower?
Reply: 2# chengkang is right; after the light diesel is extracted, the liquid volume on the tray becomes very small, which makes it easy for the tray to dry out, so this aspect needs to be taken into consideration.
Reply to 5# chengkang: Is the night drop channel similar to the liquid drop pipe in an oil collection tank? There is a drainage channel right above the extractive tray; do you have any drawings or pictures? Thank you