Mixer viscometer

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. 

Briggs, J. L. and Steffe, J. F. 1996. Mixer viscometer constant (k ) for the Brookfield small sample adapter and flag impeller. J. Texture Stud 27 671-677. 

Castell-Perez, M. E., Steffe, J. F., and Morgan, R. G. 1987. Adaptation of a Brookfield (HBTD) viscometer for mixer viscometer studies, y. Texture Stud. 18 359-365. 

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. 

Dzuy and Boger (2) employed a mixer viscometer for the measurement of yield stress of a concentrated non-food suspension and called it the "vane method . Yield stress of apple sauce samples was determined by means of the vane method by Qiu and Rao (22) using two vanes. The maximum recorded torque (Tm) value, and the diameter (Dv) and the height (H) of the vane were used to calculate the yield stress (Ov) according to the equation ... 

Tests were conducted to compare the effect of KC1 and TKPP on the rheology of an unweighted (nondispersed) and a weighted (dispersed) drilling fluid. All fluids were mixed in an industry standard Hamilton Beach mixer. The rheology of each fluid was then measured in a Fann viscometer at 120°F at 300 rpm and 600 rpm. 

In general a rotating part of a machine in the mbber industry the term refers particularly to the contoured rolls of an internal mixer and to the mushroom-shaped rotor of the Mooney Viscometer. 

Different speeds will provide different shear rates and perhaps different apparent viscosities for many viscous fluids. Apparent viscosities measured by a mixing impeller are more useful for mixer design than those obtained with a viscometer, because the appropriate distribution of shear rates are included in the measurements. 

Rubber mixes were prepared in the Banbury mixer according to the recipes in Table 1-2. The rheological properties of all compounds were determined by using an oscillating disc Monsanto Rheometer MDR 2000 and Mosanto Viscometer VM2000. 

These tests were performed using a universal Zwick tester, model 1435, coimected to a computer with appropriate software. Particle size was measured in paraffin oil using Zetasizemano S90 (Malvern Instmments) analyzer. Zeta potential of filler dispersion in water was studied by the means of Zetasizer 2000 (Malvern Instruments) apparams. Rheological properties of filler suspensions in paraffin oil were determined by viscometer RM500 (Rheometric Scientific). Dibutylphtalate (DBP) absorption was measured by means of an Absorptometer C (Brabender). The modification process was carried out in Brabender Measuring Mixer N50 at following parameters temperature 125°C rotor speed 40 RPM duration 0,5 h. 

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