Mixers concentric cylinder

Fig. E7.9a Mixing of unmatured linoleum compound between concentric cylinder mixers, (a) Method of loading—initial condition, (b) After one revolution, (c) After 20 revolutions. Diameter of inner cylinder, 1 in radial clearance, 0.25 in. [Reprinted by permission from J. T. Bergen et al., Criteria for Mixing and the Mixing Process, paper presented at the 14th National Technical Conference, Society of Plastics Engineers, Detroit, 1958.]...

Hydrodynamic Analysis of an Idealized Internal Mixer Consider the idealized mixer shown in the accompanying figure, consisting of two concentric cylinders in relative motion with a step change in clearance. Calculate the mean shear stress in the narrow gap. 

The Two-cylinder Mixer Two concentric cylinders contain a viscous liquid. A vertical slice of fluid contains black die, which does not affect the rheological properties. Two experiments are carried out (a) the outer cylinder rotates clockwise at 1 rpm for 5 min. (b) the outer cylinder rotates alternately clockwise and counterclockwise at 2 rpm, 15 s in each direction, for a total of 2.5 min. Which mode of motion leads to better mixing ... 

An in-line measurement is performed in a process line an on-line measurement is performed in a bypass loop from the main process line and the food may be returned to the main process line after measurement is performed. A near-line measurement is performed on a sample taken from a process line which is often discarded after measurement. Because foods are complex materials (e.g., suspensions, emulsions, gels), stmctural changes may take place during sampling (e.g., flow through a valve) for on-line and near-line measurements (Roberts, 2003). Nevertheless, in principle, the previously described capillary flow, and rotational concentric cylinder, plate-cone, and mixer viscometers may be used for in-line, on-line, and near-line measurements. In this respect, Tamura et al. (1989) proposed a helical screw rheometer as an on-line viscometer. The empirical measurement methods described previously are used primarily in near-line measurements. 

Plant food dispersions such as tomato concentrates and concentrated orange juice are important items of commerce. The viscosity function and the yield stress are two important rheological properties that have received considerable attention. Corrections for slip, due to the formation of a thin layer of fluid next to solid surfaces, in a concentric cylinder viscometer depended on the magnitudes of applied torque and on the shear-thinning characteristics of the dispersion. Mixer viscometers were used for obtaining shear rate-shear stress and yield stress data, but the latter were higher in magnitude than those obtained by extrapolation of flow data. 

Mastication/Internal Mixer An apparatus consisting of concentric cylinders lined with teeth with the inner cylinder rotated to achieve a shredding action initially just for rubber. It produces a dough-like mass to which other materials can be readily added. 

Fig. 3.3 Schematic setup of the experiment for concentration measurement 1 storage tank, 2 water pump, 3 control valve, 4 flow meter, 5 downcomer, 6 packing, 7 sieve tray, 8 outlet weir, 9 gas distributor, 10 control valve, 11 primary control valve, 12 blower, 13 oxygen cylinder, 14 flow meter, 15 static mixer (reprinted from Ref. [22], Copyright 2011, with permission from CIESC)...

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