What is the effect of a pre-burning tube + dilute-phase tube + two dense-phase regeneration?
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This post was last edited by fengdingwen on 2010-12-6 at 14:45. Are there any users among those who work in this field who use a pre-combustion tube + dilute-phase tube + two-phase regeneration system? What is the effectiveness of such regeneration? What is the typical density of burnt tubes in this format? What is the burning ratio of the burned tube? What is the difference between this configuration of lean-phase tube outlet + centrifuge + primary and secondary centrifuges, and the configuration of coking tank outlet + distribution pipe + primary and secondary centrifuges? What are their respective advantages and disadvantages? Is tail burning possible in the dilute phase of this type of regenerator?
Many, but the dilute-phase tube is already quite short. The density at the bottom of the burned tank is roughly 50–130, with significant variations. The burning ratio of the burnt tank is over 90%.
Many units remove the burning tank, leaving only a pre-burning tank; this type of burning tank uses a rapid-bed system, with a density of around 100, a burning efficiency of over 90%, and a carbon fixation level in the regenerator of about 0.1%.
Reply to 2# facecat: If 90% of the catalyst in the coking vessel is coked, is the remaining 10% coking in the dilute-phase pipe at the outlet of the coking vessel?
Both the dilute-phase tube and the two-dense-phase system showed signs of charring; it seems that the figure given in the book is 8% for the dilute-phase tube, with the remaining amount being for the two-dense-phase system.
Many units replace the dilute-phase tubes with low-pressure-drop, large-pore distribution plates
Reply to 6# Zhang Tianhao: Why make the change? Is it because of the dilute-phase afterburning?
The former is a typical pre-coking chamber design, while the latter is a regeneration process with a rapid-bed and turbulent-bed main air stream connected in series at both ends. Their regeneration efficiency is quite high; according to relevant reports, the latter boasts the highest efficiency among all existing regeneration methods, and it represents the first patented technology in the field of catalytic cracking processes in China. Their common feature is a pre-coking vessel, with a coking ratio of 90 percent; the remaining 10 percent is achieved through dilute-phase tubes and two dense phases. The operation of the coking tank involves mainly controlling the ignition temperature of the coking tank, the catalyst circulation ratio, as well as the volume and density of the material stored in the coking tank. For large-scale heavy oil catalysis, the density of the coking drum is over 200. The key to complete regeneration at high temperatures is to maintain the temperature of the coking tank at 683 degrees, and the temperature of the dilute-phase tubes above 700 degrees; otherwise, the carbon content in the catalyst cannot be reduced, and incomplete combustion of CO will lead to post-combustion phenomena.
Reply to 8# BJYTABC: I want to know how it works in practical applications What you say is theoretical.