Catalytic cracking riser tube feeding mixing section structure for inhibiting back-mixing of catalyst

Abstract

The invention belongs to the technical field of petrochemical industry, and mainly relates to a feeding mixing section structure for inhibiting back-mixing of a catalyst in a catalytic cracking riser tube; axial guide plates (2) are arranged above a raw oil atomizing nozzle; a circumferential guide plate (3) is arranged between every two adjacent axial guide plates (2); the upper ends of the axial guide plates (2) are provided with an auxiliary gas diversion sleeve (6); a cavity is arranged between the auxiliary gas diversion sleeve (6) and a tube wall of a feeding mixing section of a riser tube reactor; the upper end surface of the cavity is communicated with a lifting device by a ring-shaped gap (7); the tube wall of the feeding mixing section of the riser tube reactor is provided with an auxiliary gas inlet tube (5); and a communicating structure between the auxiliary gas inlet tube (5) and a riser tube can be formed. By adopting a 'stream-line' diversion structure, the feeding mixing section structure accelerates and promotes the mixing between raw oil and the catalyst in the catalytic cracking riser tube reactor, thus inhibiting back-mixing of the catalyst particles and effectively inhibiting coking.

Description

technical field [0001] The invention belongs to the technical field of petrochemical industry, and mainly relates to a feed mixing section structure of a catalytic cracking riser for suppressing catalyst backmixing. Background technique [0002] Catalytic cracking technology occupies a pivotal position in my country's petroleum processing industry, providing more than 70% of gasoline and about 30% of diesel in my country's market. The riser reactor is one of the core devices of catalytic cracking. High-value target products such as gasoline, diesel and liquefied gas are obtained there. [0003] According to the role played in the cracking reaction process, the entire riser reactor can usually be divided into four parts from bottom to top: the pre-lift section, the feed mixing section, the full reaction section and the outlet rapid separation zone. In the pre-lift section , the pre-lift steam (gas) enters from the bottom of the riser, mixes and contacts with the catalyst in...

AI Technical Summary

Problems solved by technology

[0013] (3) In the feed mixing section of the riser reactor, there is a relatively serious back-mixing phenomenon of the catalyst, especially in the side wall area of ​​the riser, the catalyst back-mixing is more severe, which prolongs the residence time of the catalyst and increases the The probability of repeated contact between oil and solvent will cause serious coking

[0019] Generally speaking, accelerating the mixing between oil and agent will inevitably lead to intensified back-mixing of catalyst particles, and in order to inhibit the back-mixing of catalyst particle groups, the price of slowing down the mixing speed of oil and agent has to be paid

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