Title: Fluidized BedObjective :- To determine the pressure drop across fluidized bed - To verify the Carman- Kozeny equation- To observed the differences between particulate and aggregative fluidization. Introduction:A fluidized-bed reactor (FBR) is a combination of the two most common, packed-bed and stirred tank, continuous flow reactors. In FBR, the substrate is passed upward through the immobilized enzyme bed at a high enough velocity to lift the particles. However, the velocity must not be so high that the enzymes are swept away from the reactor entirely. This type of reactor is ideal for highly exothermic reaction because it eliminates local hot-spots, due to its mass and heat transfer characteristics mentioned before. The increase in FBR use in todays industrial world is due to the inherent advantages of the technology. FBR perform uniform particle mixing and temperature gradients and ability to operate reactor in continuous state. On the other hands, FBR does have its draw-backs, which must take consideration. FBR need to increased reactor vessel size to solve the expansion of the bed materials in the reactor. The requirement for fluid to suspend the solid material necessitates that a higher fluid velocity is attained in the reactor. The high gas velocities present in this style of reactor often result in fine particles becoming entrained in the fluid. This may continue is an expensive problem even with other entrainment reducing technologies. The fluid-like behaviors of the fine solid particles with the bed eventually result in the wear of the reactor vessel. This can require expensive maintenance and upkeep for the reaction vessel and pipes. If fluidization pressure is suddenly lost, the surface area of the bed may be suddenly reduced. This can either be an inconvenience, such as runaway reaction.Possible solid particle fluid mixture state are: fixed bed, stationary fluidized bed, bottom feeding and overflow at the free surface of the bed, or vice versa, vertical conveying in the dense bed, low density vertical and horizontal conveying, downward particle movement in the dense bed and spouted bed. Dense phase, non-fluidized solid floe, in which particles move en bloc, with little relative velocity, has been referred to as moving-bed flow, packed bed flow or slip-stick flow. The voidage is close to the minimum fluidization value. Vertical down flow is often used with the fluid moving faster than solids. Upflow of non-fluidized particles is not common. The spouted bed is a combination of a jet-like upward moving dilute fluidized phase surrounded by a slow downwards moving bed through which gas percolates upwards. The use of such system is limited to a few physical operations with large particles. Using some bed expansion and higher flow rates will give higher mass transfer rates from the liquid to the particles. Clogging and dead zones will also be avoided and attrition may help in controlling. Depending on particle size and density, liquid and gas flow rates, the use of recycle and bed geometry, several mixing patterns may be obtained in which the liquid phase and the solid phase are mixed or not.

It is most often applied in immobilized-enzyme catalysis where viscous. Particulate substrates are to be handled. FBR are used for produce gasoline and other fuels, along with many other chemicals. Many industrials produced polymers are made using FBR technology, such as rubber, vinyl chloride, polyethylene, styrenes and polypropylene. Various utilities also use FBRs for coal gasification, nuclear power plants, and water and waste water treatment setting. Equipment: