What does the two-phase flow in the regenerator that people often talk about refer to?

It’s not easy to say; just take a look at the location of the pressure tapping point. The reserve amount is simply determined based on the density measurements; under normal circumstances, the reserve amount at the second density level of the regenerator is located at the very bottom of the regenerator

The two-phase region in the regenerator is specifically related to that of the coking drum regenerator; that is, if the outlet of the coking drum is equipped with a large-pore distribution plate, it refers to the area above this plate. There, the linear velocity decreases due to the increase in diameter, resulting in a two-phase region, although the density remains around 300 as well. If the outlet of the burned tank is a dilute-phase pipe, then the annular space formed between this dilute-phase pipe and the wall of the regeneration settler is primarily used for collecting catalyst; as a result, the flow rate of the fluidizing gas in this area is low. This is in line with the original definition of dilute phase, where the density is high, exceeding 600. 　The second catalyst unit at Takahashi Petrochemical features a coaxial arrangement of the reactor and regenerator; however, the regenerator is a new type that induces rapid turbulence. An annular large-pore distribution plate is added in the middle of the regenerator, and its upper part also consists of a two-phase region with a density similar to that of the current coking tanks equipped with large-pore distribution plates, around 300, which is relatively low. A regenerator extraction hopper was added between the two Secret phases; at that time it was called the three Secret phase, and it is actually what is now known as the catalyst extraction hopper.