Relationship between the upper gas phase temperature and lower gas phase temperature of a tray layer and the liquid phase withdrawal temperature of that tray layer
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Under normal operating conditions of an atmospheric pressure tower, what is the order of temperatures among the gas phase temperature at the upper part of a tray, the gas phase temperature at the lower part of that tray, and the liquid phase withdrawal temperature of that tray?
Taking the temperature of the liquid layer as the macroscopic reference point, the gas phase below the liquid layer > the liquid layer > the gas phase above the liquid layer.
So what’s the reason why the liquid phase temperature inside the tower is sometimes higher than the gas phase temperature in the layer below?
Just like when you drink hot soup, there are specified requirements for the import process; it must meet these process conditions. If it cannot be satisfied, then it is a matter of human beings. The operating conditions, which have been determined during the design of a production setup, must be followed by the operators. As the title suggests, there are three states for the gas and liquid feeds in a distillation column: saturated feed state, unsaturated state, and supersaturated state. If the temperature of the liquid is higher than that of the rising vapor, the less volatile components in its phase are not washed out and move from the gas phase to the liquid phase. I’m not sure what the actual situation of your problem is, or which category of distillation feed condition it falls under; please clarify.
I agree; the distillation process is a process of mass and heat transfer, following certain temperature distribution patterns.
It’s the atmospheric pressure column in oil refining units; sometimes the temperature of the liquid phase is higher than that of the gas phase below it. Could it be that there is too much liquid medium flowing to the lower trays, thereby cooling the gas phase and causing its temperature to drop below that of the liquid phase? Is that how it can be understood?
What I mean is that it is necessary to control things in accordance with the operating conditions of the equipment. The conditions of the materials entering the tower must meet the design parameters. If this cannot be ensured, abnormalities will occur; it’s not just a matter of temperature, as both the quality and output of the product will be affected. Therefore, strict control is needed in this regard. If any abnormalities do occur, they need to be analyzed and assessed comprehensively; it’s not just a matter of temperature changes – other reaction data must also be taken into account to identify issues in certain areas, for reference purposes.