Chemical Engineering - Chemical Reaction Engineering - Discussion

A Semi-fluidized bed can be viewed as the combination of a batch fluidized bed at the bottom and a fixed bed at the top within a single vessel. This type of technique overcomes the disadvantages of fluidized bed namely back mixing of solids, attrition of solids and problems involving erosion of surfaces. This also overcomes certain drawbacks of the packed bed, viz, Non-uniformity in temperature in the bed, channel flow and segregation of solids.

The semi fluidized bed is characterized by a fluidized bed and a fixed bed in series with single contacting vessel, adding mixer in the fluidized section.

May I know the main difference between fluidised bed and semi fluidised bed reactors?

I think fluidised bed gives max conversion due to more surface area of the catalyst.

What is increasing order of conversion of giving reactors?

@Kd Krishan.

What do you mean about this can you please elaborate it more explicitly.

In Packed bed an external force may inhibit the reaction.

This may be because in Semi Fluidized bed the Flow of reactant can controlled so that the contact time can be increased than the fluidised bed. In Packed bed an external force may inhibit the reaction.

Can any one please explain the reason behind this?