The draw-off temperature in the middle section of the catalytic fractionation tower cannot be reduced
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The extraction temperature in the middle section of the fractionation tower remains high. Methods that have been tried include reducing the diesel extraction temperature, increasing the amount of slurry returned to the tower, and lowering the reaction temperature (however, the inlet and outlet points at the upper and lower ends of this middle section cannot be adjusted). Yet the diesel extraction temperature in that section still stays high. What should be done?
Are there specific operational parameters? See if there is any room for adjustment. . .
Does the temperature not drop, or does the temperature reading remain unchanged? If the temperature still doesn’t drop even after making all the adjustments you mentioned, it’s necessary to consider whether there is a problem with the gauge. Second, regarding the issue you mentioned of the temperature drop not being able to be reduced, there’s definitely no change at the 95% level for diesel; what are the results of your sampling and analysis?
The first reaction is usually to wonder if there’s a problem with the instruments!
If the dry point of the diesel does not change, it may be the raw materials or the reaction temperature that have led to an increase in diesel production. If the diesel dry point is too high, it may be a problem with the lower trays.
I agree with you. It always seems to be a problem with the instruments.
Check whether there are any changes in the 95% distillation point of diesel and its distillation volume, as well as whether there are significant changes in the properties of the raw materials and the product distribution; has the yield of diesel increased?
Look at the trends; if the dry point of the diesel changes while the extraction temperature remains constant, then there is a problem with the instrument, or it’s necessary to have the instrument calibrated.
Check the overall temperature gradient variation in the fractionation tower, as well as whether there are changes in the amount of oil and gas or their temperature； Was the flow rate or reflux temperature of backflows such as re-refining oil not adjusted in a timely manner? ? ? Next, check the pressure changes in the fractionation tower.
Increase the circulation volume in Stage 1 and reduce the temperature returning to the tower
1. Lower the temperature below the single-layer plate. 2. Increase heat absorption from the middle layer – why then can’t the temperature be reduced?