perry s chemical engineers phần 6 potx

... 1993). DIMENSIONLESS GROUPS For purposes of data correlation, model studies, and scale-up, it is useful to arrange variables into dimensionless groups. Table 6- 7 lists many of the dimensionless groups ... relaminar- ization. Stress transport models provide equations for all nine Reynolds stress components, rather than introducing eddy viscosity. Algebraic closure equations for the Reynolds...

Ngày tải lên: 06/08/2014, 13:22

... fraction of phase i Dimensionless Dimensionless Re Reynolds number Dimensionless Dimensionless s Density ratio Dimensionless Dimensionless U .S. customary Symbol Definition SI units units s Entropy ... mass J/(kg ⋅ K) Btu/(lbm ⋅ R) S Slope Dimensionless Dimensionless S Pumping speed m 3 /s ft 3 /s S Surface area per unit volume l/m l/ft St Strouhal number Dimensionless Dimensionl...

Ngày tải lên: 06/08/2014, 13:22

... between vessel and pump; S 0 = system speed as given by Eq. (6- 80), assumed independent of pressure; p 1 = initial vessel pressure; p 2 = final vessel pressure; and p 0 = lowest pump intake pressure ... of pressure drop. A common error is to assume that pressure drop and frictional losses are equiva- lent. Equation (6- 16) shows that in addition to frictional losses, other factors such as...

Ngày tải lên: 06/08/2014, 13:22

... investigators. In some cases, statistical analysis of pressure fluc- tuations has been used to distinguish flow patterns. Figure 6- 24 (Alves, Chem. Eng. Progr., 50, 449–4 56 [1954]) shows seven flow ... the pressure of the surroundings into which the gas flow discharges. The pressure drops from the exit pressure to the pressure of the surroundings in a series of shocks which are highly non...

Ngày tải lên: 06/08/2014, 13:22

... Multiphase systems introduce such design criteria as solids suspension and gas dispersion. In very viscous systems, helical rib- bons, extruders, and other specialized equipment types are favored over ... vertical solid/liquid flow, but also to gas/solid flow and to horizontal flow. For fast-settling slurries, ensuring conveyance is usually the key design issue while pressure drop is somewhat...

Ngày tải lên: 06/08/2014, 13:22

... similar restric- tions, vortices may periodically be shed downstream. Objects such as smokestacks, chemical- processing columns, suspended pipelines, and electrical transmission lines can be subjected ... here. Many employ the Boussinesq approximation, simplified here for incompressible flow, which treats the Reynolds stresses as analogous to viscous stresses, introducing a scalar quantity c...

Ngày tải lên: 06/08/2014, 13:22

... elements in six dimensionless groups. Proper conversions will result in the same numerical value for the dimensionless number. The dimensionless numbers used as examples are the Reynolds, Prandtl, ... Institute of Chemical Engineers; Process Consultant, The Dow Chemical Company (retired) (Section 26, Process Safety) Bryan J. Ennis, Ph.D., President, E&G Associates, and Adjunct Profes...

Ngày tải lên: 16/02/2014, 19:20

... (Concluded) U .S. Customary U .S. Customary Symbol Definition SI units System units Symbol Definition SI units System units X f C Pseudoconcentration of Mass ratios Mass ratios solute in feed for case C [Eq. ... ratio, mass ratio basis Mass ratio/ Mass ratio/ (Bancroft coordinates) mass ratio mass ratio K″ Partition ratio, mass fraction Mass fraction/ Mass fraction/ basis mass fraction mass...

Ngày tải lên: 16/02/2014, 19:20

... fraction of phase i Dimensionless Dimensionless Re Reynolds number Dimensionless Dimensionless s Density ratio Dimensionless Dimensionless U .S. customary Symbol Definition SI units units s Entropy ... ves- sel is desired, while for others high local turbulence intensity is required. Multiphase systems introduce such design criteria as solids suspension and gas dispersion. In very viscou...

Ngày tải lên: 27/06/2014, 14:20

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