Sabri Ergun
Encyclopedia
The Ergun equation, derived by the Turkish
chemical engineer
Sabri Ergun in 1952, expresses the friction factor
in a packed column
as a function of the Reynolds number:
where
and 
are defined as
and 
where:
is the pressure drop across the bed,
is the length of the bed (not the column),
is the equivalent spherical diameter of the packing,
is the density
of fluid,
is the dynamic viscosity of the fluid,
is the superficial velocity
(i.e. the velocity that the fluid would have through the empty tube at the same volumetric flow rate), and
is the void fraction of the bed(Bed porosity at any time).
Extension of the Ergun equation to fluidized beds is discussed by Akgiray and Saatçı (2001).
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
chemical engineer
Chemical engineer
In the field of engineering, a chemical engineer is the profession in which one works principally in the chemical industry to convert basic raw materials into a variety of products, and deals with the design and operation of plants and equipment to perform such work...
Sabri Ergun in 1952, expresses the friction factor
Friction factor
Friction factor can refer to:* Darcy friction factor* Fanning friction factor* Atkinson friction factor...
in a packed column
Packed bed
In chemical processing, a packed bed is a hollow tube, pipe, or other vessel that is filled with a packing material. The packing can be randomly filled with small objects like Raschig rings or else it can be a specifically designed structured packing...
as a function of the Reynolds number:
where
and are defined as and where:
is the pressure drop across the bed, is the length of the bed (not the column), is the equivalent spherical diameter of the packing, is the densityDensity
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
of fluid,
is the dynamic viscosity of the fluid, is the superficial velocitySuperficial velocity
Superficial velocity , in engineering of multiphase flows and flows in porous media, is an hypothetical fluid velocity calculated as if the given phase or fluid were the only one flowing or present in a given cross sectional area. Other phases, particles, the skeleton of the porous medium, etc...
(i.e. the velocity that the fluid would have through the empty tube at the same volumetric flow rate), and
is the void fraction of the bed(Bed porosity at any time).Extension of the Ergun equation to fluidized beds is discussed by Akgiray and Saatçı (2001).