Pressure Drop AP in Tubular Plug Flow Reactors

PRESSURE DROP (AP) IN TUBULAR (PLUG FLOW) REACTORS 

It is important to determine pressure drop of fluid through tubular reaetors, sueh as paeked, fixed, and fluidized bed reaetors where, eatalysts are employed. AP is an important faetor that influenees the design and operation of sueh reaetors. Ergun [3] developed a useful 

AP equation arising from simultaneous turbulent kinetie and viseous energy losses that is applieable to all flow types. Ergun s equation relates the pressure drop per unit depth of paeked bed to eharaeteristies sueh as veloeity, fluid density, viseosity, size, shape, surfaee of the granular solids, and void fraetion. The original Ergun equation is  

Equation 6-107 gives the total energy loss in fixed beds as the sum of viseous energy loss (the first term on the right side of the equation) and the kinetie or turbulent energy loss (the seeond term on the right side of the equation). For gas systems, approximately 80% of the energy loss depends on turbulenee and ean be represented by the seeond term of Equation 6-107. In liquid systems, the viseous term is the major faetor. 

For paeked beds in either laminar or turbulent flow the Ergun equation is 

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