Coaxial settler-free two-stage-cyclone-series-connected gas-solid separation method and equipment

Abstract

The invention relates to a coaxial settler-free two-stage-cyclone-series-connected gas-solid separation method and belongs to the technical field of petrochemical engineering and fluidization. The method is used for solving the problems that coaxial type settlers undergo coking and excessive oil vapor thermal cracking. The method comprises the processes of two-stage gas-solid separation, dipleg flutter valve discharge and oil vapor lead-out and is characterized in that due to a coaxial settler-free design, the series connection of two folded risers and external two stages of cyclone separation is adopted, and catalyst diversion facilities are designed; the catalyst diversion facilities are connected with the two stages of cyclone separation, so as to form a closed separation system, a catalyst and oil vapor, which are discharged from second-stage flutter valves, are closely guided to the closed separation system, and second-stage dipleg flutter valves adopt vertical discharging. The method disclosed by the invention has the advantages that the problem of coking of the settlers is eliminated; due to closed rapid cyclone separation, the gas-solid separation efficiency reaches over 98%, and the retention time of the oil vapor is shorter than 5 seconds, so that the reaction of excessive thermal cracking of the oil vapor is obviously reduced, the yield of dry gas is lowered, and the yield of products is increased; the discharging of diplegs is smooth, so that blow-by is avoided; the equipment maintenance is facilitated, and the equipment investment is greatly reduced. The invention further provides a two-folded riser reactor, external two stages of cyclone separators, vertical two stages of diplegs and catalyst diversion equipment, which are used for implementing the method disclosed by the invention. The method and equipment are applied to devices for catalytic cracking, catalytic pyrolysis and the like.

Description

technical field [0001] The invention belongs to the technical fields of petrochemical industry and fluidization, and in particular relates to a coaxial non-settler two-stage cyclone series gas-solid separation method and equipment. Background technique [0002] The outlet of the riser reactor of the catalytic cracking unit in the refinery is equipped with a gas-solid rapid separation device, which is used to realize the rapid separation of oil gas and catalyst and terminate the cracking reaction. In the early days, there were umbrella caps, inverted L, T-shaped and other structural types, and the separation efficiency was generally 70% to 80%. The separated oil and gas rose slowly in the larger-diameter settler, and then entered the secondary separator at the top of the settler. This part of oil and gas stays in the settler for 20 to 50 seconds, and there are still reactions such as excessive thermal cracking and condensation at a high temperature of 500°C, which affects the...

AI Technical Summary

Problems solved by technology

In this scheme, the material leg of the secondary separator adopts a folded tube structure, which is not conducive to the flow of fine powder, and the wing valve placed in the stripping section is easily buried by the catalyst, resulting in poor feeding of the material leg of the secondary separator and a large amount of catalyst loss.

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