A multi-stage atomized heavy oil catalytic cracking anti-coking nozzle

Abstract

The invention belongs to a catalytic cracking device in the field of petroleum refining and provides a multistage atomized heavy oil catalytic cracking anti-coking nozzle. The multistage atomized heavy oil catalytic cracking anti-coking nozzle comprises an inner tube (5), an outer tube (3), a shower nozzle (1), a raw oil inlet (14) and a primary steam inlet (15), the raw oil inlet (14) is communicated with a collecting tube chamber (13) and is communicated with a mixing chamber (10) in a shape of a circular truncated cone through a plurality of evenly-distributed raw oil nozzles (12), and the first stage pulverization of raw oil is obtained when the raw oil enters the mixing chamber. The second stage pulverization is carried out on the raw oil in the mixing chamber through primary steam sprayed in the mixing chamber from a primary steam nozzle (11). The third stage pulverization is carried out on the raw oil in the inner tube after the second stage pulverization. A secondary steam spraying hole I (2-2) enables the raw oil to conduct the fourth stage pulverization. The multistage atomized heavy oil catalytic cracking anti-coking nozzle adopts a multistage atomizing mode to strengthen pulverization effects, therefore, coking of the raw oil on the wall of a riser reactor is avoided.

Description

technical field [0001] The invention belongs to a catalytic cracking device in the field of petroleum refining, and mainly relates to a multi-stage atomization heavy oil catalytic cracking anti-coking nozzle. Background technique [0002] Raw oil feeding atomization nozzle is an important equipment of catalytic cracking unit in the field of petroleum refining. In the tube reactor, it mixes and reacts with the catalyst in the riser reactor. [0003] In recent years, the feed oil atomization nozzles used in catalytic cracking units mainly include throat type LPC type (90209410.6), KH type with supersonic atomizing steam double throat type (89207961.9, 200420066089.3), BWJ type with swirl structure (98233035.9,), UPC-ɑ type with porous steam distributor (00109776.8), and CCK type with secondary atomization structure (99219391.5); foreign similar technologies mainly include S&W The company's target nozzle, the multi-nozzle Optimix nozzle with a built-in porous steam distributo...

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Problems solved by technology

[0004] However, in the actual use process, the above-mentioned nozzles have more or less the following problems: first, the atomization effect of the feedstock oil needs to be further improved; Coking phenomenon occurs; the third is that the injection speed of the atomized raw material oil droplets sprayed out by the nozzle is too high, which seriously breaks the catalyst; the fourth is that the atomized steam and the raw material oil interact with each other in the inlet area of ​​the nozzle, and even appear when the fog When the pressure of steam (or raw oil) fluctuates, the raw oil (or atomized steam) cannot be introduced into the nozzle

[0007] Through research, it is found that the shortcomings of 200410010045.3 mainly lie in two aspects: one is that there is still an accumulation of oil film on the inner wall of the local area inside the nozzle; "Sensitive" because the 200410010045.3 steam injection hole is connected with the secondary steam chamber. When the steam pressure and flow fluctuate, or even the raw oil flow fluctuates, it may cause the catalyst to suck back and even cause the steam injection hole to wear

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