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A packed bed of uniform spherical particles of diameter, d= 2.5 mm, density ρs= 4000 kg/m3...

A packed bed of uniform spherical particles of diameter, d= 2.5 mm, density ρs= 4000 kg/m3 , and voidage e= 0.45 is fluidised by means of a liquid of viscosity μ= 1 mN s/m2 and density ρ= 900 kg/m3 . (a) Starting from Carman’s and Ergun’s equations reported in the attached equations sheet, derive the corresponding expressions for the minimum fluidising velocity, umf, for both equations and explain their meaning.

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