Catalytic cracking diesel
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Friends, could someone tell me why the temperatures at the upper and lower outlets of the diesel fractionation tower are reversed? Is the temperature of extraction at the top higher than that at the bottom?
Personal opinion: The position of the thermocouple determines this – the one located higher measures the gas phase temperature, so it shows a higher value, while the one located lower measures the liquid phase temperature, resulting in a lower value. This is just my opinion; please correct me if I’m wrong.
It was like this before too, or did it become like this the day after?
Is it a problem with the gauge, perhaps it was connected reversely? The latter case is an abnormal display due to a fault in the gauge
Happy New Year! First of all, may I ask what the exact temperatures are for the upper and lower draws at the moment? What are the valve positions? Is the discharge working properly? If the valve position is normal and the amount is small, consider whether the extraction outlet is blocked or there is a problem with the lower extraction valve. Bring up the recent pressure drop trend of the entire fractionation tower to see if it has increased, and consider whether salt accumulation in the fractionation column is severe.
The upper and lower drawing temperatures are generally 160°C, 172℃
Thermocouple positions. It is guessed that the one on the higher side is inserted into the tower, while the one on the lower side is inserted into the distillation outlet line.