Abstract: The industrial applications of Crosser grids, a new type of internals for dense gas-solids fluidized bed reactors developed by China University of Petroleum(Beijing) were reviewed. The design principle of the Crosser grid and its effects on improving gas-solids contact and suppressing solids backmixing were described. The emphasis was on its industrial applications in the regenerators and strippers of fluid catalytic cracking (FCC) units in petroleum refineries. These successful applications proved the effectiveness of the Crosser grid on promoting the performances of both FCC regenerators and strippers due to its effective improvements on bed fluidization and suppression on axial solid backmixing. Finally, the application possibility of Crosser grid in MTO plant and the effect on product distribution and regenerator charing effect were analyzed and discussed.

Key words: internal, fluidized bed, fluid catalytic cracking, methanol to olefins, fluidization quality, solid backmixing