Necessary conditions for forming a fluidized bed:
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Necessary conditions for forming a fluidized bed:
To form a fluidized bed, the gas velocity must be maintained between the critical fluidization velocity and the entrainment velocity. The critical fluidization velocity is the gas velocity at which fluidization begins, also known as the minimum fluidization velocity. The carry-out velocity is the velocity of the gas at which the fluidized material (such as a catalyst) begins to be carried away by the gas.
To achieve a fluidized state, it is necessary to have a gas flow velocity high enough to cause the material stream to \"boil\", without however blowing the material away.
Fluidized beds are divided into dispersed fluidized beds and aggregated fluidized beds; generally, liquid-solid systems tend to form dispersed fluidized beds. When the gas velocity exceeds the initial fluidization velocity, a fluidized bed is formed; when it exceeds the initial bubbling velocity, a bubbling bed is created; when it exceeds the turbulence threshold velocity (0.6 m/s), a turbulent bed is attained; and when it exceeds the rapid flow threshold velocity (0.9–3.0 m/s), a rapid flow bed state is achieved. But what we should be discussing are Class A particles.
Take a look at the Q&A on catalytic cracking unit technology; it’s very comprehensive
The critical gas velocity must be reached, with a constant pressure drop
It is necessary to maintain the flow rate of the gas medium between the critical fluidization velocity and the carry-away velocity.
Is there a better answer for forming a sulfide bed?
To form a fluidized bed, an oil-based fluidizing agent, that is, a catalyst, is required, as well as a fluidizing medium, which is air. The most essential condition is that the air must be able to fluidize the catalyst
The fluidization medium distribution plate must have sufficient pressure drop to ensure stable bed fluidization
It is mainly related to the gas velocity. Depending on the gas velocity, a bed generally goes through the following stages: 1. Fixed bed, 2. Bubble bed, 3. Fluidized bed, 4. Transport bed. For more information, you can read \"Principles of Fluidization Engineering\" written by Academician Xie Kechang: handshake
The answer upstairs is correct! :lol
There are three necessary conditions: 1. A container required for fluidization, such as a lift pipe, settler, regenerator, etc. 2. The fluidized medium, such as catalysts, etc. 3. Media used for fluidization, such as air, water, etc.
Fluidized catalytic cracking FCC Fluidizing medium Catalyst Fluidization power 0.35MPa main air Reaction-reaction pressure difference Inclined tube pressure difference Fluidization site Rapid bed Turbulent bed