초록 ▼

In a fluid catalytic cracking (FCC) unit, a regenerator or a stripper includes a standpipe for circulating catalyst from one vessel to another, the standpipe having an inlet design which reduces gas entrainment during catalyst transport by partial de-fluidization in the standpipe inlet region. The s

In a fluid catalytic cracking (FCC) unit, a regenerator or a stripper includes a standpipe for circulating catalyst from one vessel to another, the standpipe having an inlet design which reduces gas entrainment during catalyst transport by partial de-fluidization in the standpipe inlet region. The standpipe inlet design could include multiple inlet openings through the top of the standpipe or from the side wall by means of slots, or both, and a horizontal disk surrounding the standpipe below the slots for blocking the upward flow of bubbles, the combination thereby forming a dense fluidization zone above the disk and surrounding the inlet, including the slots. Additionally, the disk may include a downwardly-projecting lip or edge forming an inverted void space around the standpipe and the downwardly-projecting edge may further include vent holes around its circumference which allow bubbles trapped under the disk to be vented outside the standpipe inlet region. Above and below the disk and surrounding the standpipe, gas injection rings may be used to prevent the dense fluidization zone above the disk from complete de-fluidization, thus assisting the catalyst to remain fluidized and flow smoothly into the standpipe either through the slots or at the very top of the open standpipe, or both.

대표청구항 ▼

[ What is claimed is:] [1.]1. In a fluidized bed of particulate solids for use in a apparatus, said process including a fluidizing gas for keeping said particulate solids in a fluidized bed mode, a conduit for transferring said particulate solids into said fluidized bed and a standpipe for transferr

[ What is claimed is:] [1.]1. In a fluidized bed of particulate solids for use in a apparatus, said process including a fluidizing gas for keeping said particulate solids in a fluidized bed mode, a conduit for transferring said particulate solids into said fluidized bed and a standpipe for transferring said particulate solids out of said fluidized bed, wherein said standpipe protrudes into said fluidized bed, the improvement comprising:an inlet portion of said standpipe including an open upper of said standpipe for receiving particulate solids from said fluidized bed, said inlet portion being completely submerged in said fluidized bed; anda non-perforated disk surrounding said standpipe below said open upper end of said standpipe for trapping a portion of said fludidizing gases thereunder and inducing partial de-fluidization particulate solids thereabove.