A rotational double coaxial cylinder viscometer

1972 ◽  
Vol 11 (3-4) ◽  
pp. 275-285 ◽  
Author(s):  
B. Enoksson
Keyword(s):  
Coaxial Cylinder ◽  
Cylinder Viscometer

Flow behaviour of low solids fresh cheeses

1993 ◽  
Vol 60 (4) ◽  
pp. 593-601 ◽  
Author(s):  
Jozef Korolczuk
Keyword(s):  
Shear Rate ◽  
Initial Level ◽  
Coaxial Cylinder ◽  
Initial Value ◽  
Exponential Equation ◽  
Final Stress ◽  
Final Yield ◽  
Time Required ◽  
Rate Relation ◽  
Cylinder Viscometer

SummaryA computerized, coaxial cylinder viscometer, controlled by a function synthesizer, was used to study the stress characteristics of acid fresh cheeses containing 7·5–8·5% protein and 0–20% fat in total solids, as a function of shearing time (0–3600 s) and of shear rate (0–4·5 s–1). For a given shear rate the stress diminished with time, following an exponential equation. The hypothetical final stress level (Sf for the shearing time t = ∞) represented about half its initial value (Si). For four cheese samples, the time required for the stress to become equal to Sf + (Sf – Sf)/e was 340–560 s. The stress-shear rate relation indicated shear thinning behaviour. The effect of shearing time showed that the material was thixotropic. The cheeses exhibited plastic flow. The initial and final stress levels were hyperbolic functions of the shear rate. Bingham final yield stress (for t = ∞) was 14–50 Pa. It was 15–25% higher for increasing than for decreasing shear rate. Bingham viscosity (for t = ∞) was between 2 and 6 Pa s. It was 10–20% higher for decreasing shear rate. The initial level of Bingham viscosity was ˜ 30% higher than its final value.

Flow of Greases Under the Action of Complex Shear

1968 ◽  
Vol 90 (3) ◽  
pp. 604-607 ◽  
Author(s):  
G. V. Vinogradov ◽  
A. A. Mamakov
Keyword(s):  
Shear Stress ◽  
Axial Direction ◽  
Coaxial Cylinder ◽  
Great Decrease ◽  
Annular Space ◽  
Uniform Shear ◽  
Complex Shear ◽  
Shear Stress Field ◽  
Limiting Value ◽  
Cylinder Viscometer

Experiments were performed in a coaxial cylinder viscometer in which there were realized separately and simultaneously flows of grease and bright stock (Newtonian fluid) in the axial and peripheral direction. The latter was at uniform shear stress field. The effect of peripheral on axial-flows was a great decrease in resistance toward deformation in the axial direction. This is a very important peculiarity of greases, which are non-Newtonian media, when considering their flow in labyrinth boxes and some other devices. The effect of axial on peripheral flow showed somewhat increased resistance toward the latter. Such behavior was attributed to continuous inflow of fresh grease into the annular space where it did not remain long enough for structural destruction to reach a limiting value.

Study on the Variety of Rheological Properties and Thermal Analysis of Modified Coal Tar Pitch with 1,4-Benzenedimethanol

2014 ◽  
Vol 602-603 ◽  
pp. 304-307 ◽  
Author(s):  
Wu Chao Shi ◽  
Li Min Dong ◽  
Qiang Li ◽  
Chen Wang ◽  
Tong Xiang Liang
Keyword(s):  
Rheological Properties ◽  
Apparent Viscosity ◽  
Sulfonic Acid ◽  
Carbon Materials ◽  
Coal Tar ◽  
Coaxial Cylinder ◽  
Coal Tar Pitch ◽  
Carbon Yield ◽  
Toluene Sulfonic Acid ◽  
Cylinder Viscometer

Coal tar pitch (CTP) as carbon material was studied using 1,4-Benzenedimethanol (PXG) as modifier by p-toluene sulfonic acid (PTS) catalyst and the variety of rheological properties of modified coal tar pitch (MTP) was discussed. The apparent viscosity of CTP and MTP were measured using rotating coaxial-cylinder viscometer, and the relations between the apparent viscosity and temperature were studied. Thermal behaviors of CTP and MTP were analyzed with TG-DSC. The results showed that the viscosity of the MTP gradually decreased with the temperature rising and the viscous activation energy of the MTP is 72.92 kJ·mol-1, which was beneficial to the process for producing carbon materials and the carbon yield was greatly improved. Therefore, coal tar pitch modified with PXG was qualified to be an excellent carbon precursor.

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