Why is the nitrogen flow rate at the outlet of the dust collector in the reprocessing unit controlled by the pressure difference between the lower hopper and the elevator?

Which process is UOP’s?

You must be referring to the pressure control of the separation hopper, that is, the one located in front of the catalyst dust separator

Yes, it’s the flow control at the outlet of the dust collector; it’s essentially equivalent to pressure control in the separation hopper! Why use the pressure difference between the lower hopper of the front reactor and the elevator for control?

It’s not UOP; it’s domestic technology

This is not used to control the pressure in the separation hopper; it mainly controls the pressure difference between the lower hopper of the four reverse units and the elevator. The principle is to ensure that the pressure in the lower hopper of the four-reactor system is always higher than the pressure in the lower lifter of the same system, so that the catalyst can flow downward smoothly; the pressure difference is generally between 15 KPa and 20 KPa. The 3rd generation CCR technology results in a bottom pressure of less than 0.33 MPa in the 4th reactor; this pressure is even lower when the load is low. The N2 supply pressure in the four-reactor lifter is generally high, and in order to ensure that the catalyst can flow out from the bottom of the 4th reactor, it is necessary to reduce the pressure in the lifter. This is achieved by installing a differential pressure valve downstream of the separation hopper, which sends the N2 back to the N2 recycling system for regeneration. This mode is used in the CCR processes of UOP, Axens, and LPEC; the countercurrent moving bed regarding SEI is not very clear.

We’re not talking about the same issue. What I want to know is why the outlet flow rate of the dust collector needs to be controlled through the pressure difference between the lower hopper and the elevator