What is the role of the cross-line before the highly absorbent oil returns to the tower and before the first intermediate stream returns to the tower?

I guess, I’m not sure if it’s right? 1. Use unqualified oil as the absorbent in the reabsorption tower, and then transfer it to Unit 1 for reprocessing; by raising the temperature of this unqualified oil, the amount that can be reprocessed can be increased. 2. During shutdown, directly press the oil at the bottom of the reabsorption tower into Unit 1, which makes it easier to completely remove the oil from the bottom of the tower.

I think it’s used to purchase diesel at No. 1 Worksite

If oil is to be taken in at the start of operation at stage 1, wouldn’t it be faster to use a diesel pump to supply oil to the inlet of stage 1?

The oil components with high absorption capacity contain a larger proportion of gasoline components, which are relatively light; these components help reduce the gas-phase load on the lower trays of the tower, and are used to control the quality of diesel

I don’t think this cross-line is used for starting up or taking in oil, because generally, at the inlet of the pump in a catalytic unit, there is a light diesel feed line. At startup, gently pour in diesel and transfer it to the middle system for filling. Therefore, when it is found that the dry point of light diesel is high and it contains a large amount of heavy fractions, this is done to ensure that the quality of gasoline is not affected. Use this crossover line to pump the substandard diesel into Unit 1 for reprocessing.

1. The richly absorbed oil from the catalytic cracking fractionator is generally returned to the tower at layer 27, which affects the load on the top of the tower and thus impacts the quality of gasoline. 2. The oil rich in absorbents is returned to the tower via the primary reflux stream; generally, it is sent back 22 levels up the tower, which can increase the yield of diesel. 3. It can reduce the load on the middle and upper sections, decrease pressure drop, and improve the efficiency of the compressor.

Agree with what was said on floor 7; then the unit can be used

The rich absorption oil returning to the tower serves as a heat-extraction reflux in the distillation column; when this rich absorption oil reflux returns above the diesel extraction point, it together with the top circulation forms the upper heat-extraction system. As the rich absorbent oil increases, the top temperature of the tower decreases. When returning to the return port of Unit 1, it forms a central heat extraction system with Unit 1. Therefore, when the highly absorbent oil returns to the tower via the return inlet of Stage 1, the heat extraction in Stage 1 must be significantly reduced ； Top-loop heat extraction needs to be significantly increased; when the rich absorbent oil returns to phase one, it acts as a \"cold reflux,\" and all of this rich absorbent oil must vaporize and enter above the diesel extraction point. When the richly absorbed oil returns to the diesel extraction point, it only transfers the sensible heat between the diesel extraction temperature and the temperature at which the richly absorbed oil returns to the tower, so the amount of heat transferred is not large. It seems that this is the design approach, but it’s rarely used in No. 1 Middle School, as it isn’t conducive to heat recovery from high-temperature areas there.

The highly absorbent oil is returned to the tower in order to adjust the quality of diesel; it serves a washing function during the processing of heavy oils, thereby controlling 95% of the diesel