Are both the flap valves and anti-backflow cones in the settler of a catalytic cracking unit in a dilute phase? Why not use a running agent?
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As the title suggests: we know that the anti-backflow cone in the regenerator must be located in the dense phase, while the flap valve can be placed either in the dilute phase or in the dense phase, in order to prevent catalyst leakage. Then why are both the anti-backflow cone and the flap valve in the settler located in the dilute phase, yet there is no catalyst leakage?
The wing valve and the anti-backflow cone of the settler are not on the same horizontal level; the anti-backflow cone is located in the dense phase, so there is no risk of material leakage； In the dilute-phase condition without agent leakage, the flap valve prevents leakage since it has a valve plate in place to block it.
Reply to 2# zhxsh6666: Is the anti-backflow cone in the settler located in the dense phase? It seems to be in a dilute phase, right?
Reply to 3# 328104062: The anti-backflow cones should be in the dense phase, covered by the catalyst; otherwise, the catalyst will not flow along the material leg and will instead go into the distillation tower.
Is the anti-backflow cone in the settler in a dense phase? It seems to be in a dilute phase, right? Welcome everyone to share your insights
The rough rotation of the settler lacks a anti-backhammer mechanism
Reply to 6# sghxw: We have them, and I’m sure – you’ll see for yourself
The anti-tilt cone is used in the dense phase; it is installed quickly at the start of charging to seal the material leg； Single-rotor winged valve, prevents leakage of fluid
Settlers are also divided into dense and dilute phases. I learned something new today: the main factor preventing fluid leakage is the pressure difference. Carbon-containing catalysts also have a high density
Reply to 8# Zhu Wenxuan: What you’re referring to is probably the regenerator. When adding catalyst during operation, it needs to be added quickly in order to seal the centrifugal feed leg. At this stage, the main issue is catalyst loss; after the feed leg is sealed, the main problem becomes bed temperature
Generally, anti-backflow cones are used in the primary cyclone separator of large-scale coaxial catalytic cracking regenerators, but these anti-backflow cones are definitely located in the dense phase within the bed. The large spiral legs of the settler are also designed to prevent inversion of the cone shape. The separation efficiency of these large spirals is generally between 98.5% and 99.5%. What is your catalyst circulation rate? What is the static pressure of the catalyst beneath the coarse spinning leg? It goes without saying that the static pressure at the feed leg is much higher than the pressure of the steam rising in the stripping section; otherwise, how could the catalyst from the crude spinning section escape?