Reasons for the decrease in pressure drop in catalytic cracking cyclones
Thread Content
Reasons for the decrease in pressure drop in catalytic cracking cyclones: During the normal operation of a catalytic unit, the reasons for the decline in pressure drop in cyclones (in the regenerator or settler), as well as the associated hazards and countermeasures. I hope everyone feels free to speak!
Coking in the cyclone is the main cause, and there are many factors that affect coking, including the properties of the raw materials, operating conditions, the atomization effect of the nozzles, and the design of the cyclone itself; each case needs to be analyzed on a case-by-case basis.
If the pressure drops by about 1 Kpa, it may indicate that the catalyst is under stress; the reason could be poor operation of the flap valves, or blockages in the ash hopper or feed legs caused by coke particles, which reduces the flow area.
The main reasons for the decrease in the pressure drop of the centrifuge are: low density of the material, which prevents proper sealing of the material leg； Wing valve failure ； High content of fine catalyst powder ； Significant fluctuations in operating pressure ；
Based on my own operational experience: 1. Reasons for the decline in performance of the regenerator cyclone: 1) A decrease in the main air flow; 2) A drop in the regeneration pressure. Problems with the opening and closing of the flap valves (caused by elastic failures, deformation of equipment surrounding the flap valves that leads to impacts on them, etc.), as well as poor fluidization. 2. Reasons for the decline in performance of the reactor cyclone: 1) A reduction in the amount of medium entering the system: feed volume, gas injection volume, etc.; 2) A decrease in the reaction pressure; problems with the opening and closing of the flap valves; 4) A reduction in the steam used for stripping in the cone-shaped section, as well as a decrease in the steam used to prevent coking. In severe cases, this can lead to significant catalyst loss and an increase in the solid content, among other issues....................
It’s probably coking; the cyclone effect has decreased, resulting in less resistance to gas flow
I’ve learned a lot. Recently, the centrifugal pressure drops in our regenerator and settler have been fluctuating frequently, and this provides a theoretical basis for my future operations. Thank you to all the teachers
What everyone has said makes sense, and I would like to add a few words as well. 1. In the settler, do the vapors in the dead zone and the active zone change significantly? Have the anti-scaling steam orifice plates or gate valves been adjusted, resulting in changes in the steam volume? Things like cracks in the anti-scorching steam pipeline might have a slight impact. 2. In the regenerator, check whether the fluidization is uniform; if there are differences between the cyclones, this may be due to wear of the main air distribution pipes, detachment of internal components, sticking of flap valves, or accumulation of debris in the guide cones.
I think anything that affects the inlet linear velocity of the cyclone or the density of the inlet medium could cause changes in pressure drop； Also: I would like to know what the typical normal pressure drop is for the reactors and regenerator cyclones in everyone’s systems. Our settler 10KPA ； Regenerator around 14 kPa ； Coarse rotation around 12 kPa ；
A decrease in the pressure drop at the inlet and outlet of the cyclone separator indicates a possible leakage of fluid. The flap valve may not be able to close completely due to coking or malfunction.
Our reactor is at 11 KPA and the regenerator is at 12 KPA