| The flow of non-Newtonian fluids that react chemically are of great industrial interest [Chem. Eng. Sci., 43, 1209 (1988)]. Consider one such fluid, a Bingham plastic in laminar flow in a tubular reactor. This fluid has the following properties: | ||
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where U is the velocity, B
the viscosity, y
the yield stress, andr
stress at radius r. For laminar flow of a Bingham plastic in a cylindrical
tube, the shear< there will be core region of radius rc
near the axis where the axial velocity is uniform, |
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| The average velocity, U, over the cross section is | ||
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| where y =r/R and yc = rc/R, which can be calculated from the equation | ||
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where ,
the Bingham number. |
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| (a) Derive equations for E(t)
and F(t) for a Bingham plastic flowing in a straight cylindrical
reactor. (b) Derive an equation for the mean residence time. |
[2nd Ed. P13-16]
