Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: drop sizes

Sortuj według:

Ogranicz wyniki do:

High flow, low shear impellers versus high shear impellers; dispersion of oil drops in water and other examples

Pacek Andrzej W., Nienow Alvin W.

Chemical and Process Engineering

2021

Vol. 42, nr 2

77–-90

Flow patterns generated by two ChemShear impellers, CS 2 and CS 4 have been measured and flow numbers calculated; Fl = 0.04 for both impellers. Transient and equilibrium drop sizes, d32 μm of 3 different viscosity silicone oils agitated by a high-shear Rushton turbine, RT, a low-shear, high-flow HE3 impeller and the two ChemShears were determined. The equilibrium d32 are correlated for all impellers, by d32 = 1300(εT )−0.58 max.svv0.14 with an R2 = 0.94. However, the time to reach steady state and the equilibrium size at the same specific power do not match the above descriptors of each impeller’s characteristics. In other literature, these descriptors are also misleading. In the case of mixing time, a high shear RT of the same size as a high flow HE3 requires the same time at the same specific power in vessels of H/T = 1. In bioprocessing, where concern for damage to cells is always present, free suspension animal cell culture with high shear RTs and low-shear impellers is equally effective; and with mycelial fermentations, damage to mycelia is greater with low shear than high. The problems with these descriptors have been known for some time but mixer manufacturers and ill-informed users and researchers continue to employ them.

Diffraction measurement methods of sizes of drops in quasi-monodispersive aerosol.

Opara T.A.

Optica Applicata

2000

Vol. 30, nr 4

735-755

The assumptions of a diffraction method of determining the sizes of drops in the stream of fuel aerosol are presented. The applicability range of the due conventional calculation methods is determined. The systematic errors due to the diversified sizes of drops in the sprayed stream of liquid are indicated. The formulae allowing both correction of the measured average diameter D and an approximate evaluation of the standard deviation a of the statistical distribution p(D) of drop sizes in the stream examined are derived.