Rheological Characterization of Highly Concentrated Mineral Suspensions Using Ultrasound Velocity Profiling with Combined Pressure Difference Method

2008 ◽  
Vol 18 (6) ◽  
pp. 62114-1-62114-10 ◽  
Author(s):  
Reinhardt Kotzé ◽  
Rainer Haldenwang ◽  
Paul Slatter
Keyword(s):  
Pressure Difference ◽  
Laser Doppler Anemometry ◽  
Mining Industry ◽  
Rheological Behaviour ◽  
Ultrasound Velocity ◽  
Rheological Parameters ◽  
Rheological Characterization ◽  
Newtonian Flows ◽  
Line Measurement ◽  
Mineral Suspensions

Abstract The rheological behaviour of non-Newtonian, highly concentrated and non-transparent fluids used in industry have so far been analysed using commercially available instruments, such as conventional rotational rheometers and tube viscometers. When dealing with the prediction of non-Newtonian flows in pipes, pipe fittings and open channels, most of the models used are empirical in nature. The fact that the fluids or slurries that are used normally are opaque, effectively narrows down the variety of applicable in-line rheometers even further, as these instruments are normally based on laser or visible light techniques, such as Laser Doppler Anemometry. In this research, an Ultrasonic Velocity Profiling technique (UVP), in combination with a pressure difference (PD) measurement, was tested to provide in-line measurement of rheological parameters. The main objective of this research was to evaluate the capabilities of the UVP-PD technique for rheological characterisation of different concentrations of non-transparent non-Newtonian slurries. Kaolin, bentonite, Carboxymethyl Cellulose (CMC) and water solutions were used as model non-Newtonian mining slurries. Results determined by the UVP-PD method were compared with results obtained by off-line rheometry and in-line tube viscometry. The agreement between the UVP-PD method, tube viscometry and conventional rheometry was found to be within 15 % for all of the highly concentrated mineral suspensions investigated over a given range of shear rates. This method, if used in combination with a pressure difference technique (PD), has been found to have a significant potential in the development process of new in-line rheometers for process control within the mining industry.

scholarly journals Analytical Rheology of Honey: A State-of-the-Art Review

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1709
Author(s):  
Célia Faustino ◽  
Lídia Pinheiro
Keyword(s):  
Sugar Content ◽  
Rheological Behaviour ◽  
Principal Component ◽  
Rheological Parameters ◽  
Experimental Conditions ◽  
Thixotropic Behaviour ◽  
Ancient Times ◽  
Medicinal Properties ◽  
Complex Relationships ◽  
Temperature Time

Honey has been used as a nutraceutical product since ancient times due to its nutritional and medicinal properties. Honey rheology influences its organoleptic properties and is relevant for processing and quality control. This review summarizes the rheological behaviour of honeys of different botanical source(s) and geographical locations that has been described in the literature, focusing on the relation between rheological parameters, honey composition (moisture, water activity, sugar content, presence of colloidal matter) and experimental conditions (temperature, time, stress, shear rate). Both liquid and crystallized honeys have been addressed. Firstly, the main mathematical models used to describe honey rheological behaviour are presented highlighting moisture and temperature effects. Then, rheological data from the literature regarding distinct honey types from different countries is analysed and results are compared. Although most honeys are Newtonian fluids, interesting shear-thinning and thixotropic as well as anti-thixotropic behaviour have been described for some types of honey. Rheological parameters have also been successfully applied to identify honey adulteration and to discriminate between different honey types. Several chemometric techniques have also been employed to obtain the complex relationships between honey physicochemical and rheological properties, including partial least squares (PLS), principal component analysis (PCA) and artificial neural networks (ANN).

scholarly journals Effects of Rheological Parameters of a Viscoplastic Fluid on Peristaltic Pumping in a Cylindrical Tube

2019 ◽  
Vol 286 ◽  
pp. 09003
Author(s):  
H. Rachid ◽  
M. Ouazzani Touhami
Keyword(s):  
Fluid Model ◽  
Pressure Rise ◽  
Cylindrical Tube ◽  
Mechanical Efficiency ◽  
Viscoplastic Fluid ◽  
Rheological Parameters ◽  
Rheological Characterization ◽  
Peristaltic Pumping ◽  
Fluid Foods ◽  
Circular Cylindrical Tube

In this paper, we study theoretically the peristaltic transport of a generalized four-parameter plastic fluid in a circular cylindrical tube. The present fluid model is presented for the rheological characterization of inelastic fluid foods. Long wavelength and low Reynolds number approximations are taken into account to get solution. The effects of embedded parameters on pressure rise, frictional force and especially on the mechanical efficiency have been numerically displayed and physically discussed.

Sensory Evaluation and Rheological Behavior of Commercial Mayonnaise

2007 ◽  
Vol 3 (1) ◽  
Author(s):  
Dayane Izidoro ◽  
Maria-Rita Sierakowski ◽  
Nina Waszczynskyj ◽  
Charles W. I. Haminiuk ◽  
Agnes de Paula Scheer
Keyword(s):  
Shear Stress ◽  
Yield Stress ◽  
Sensory Evaluation ◽  
Rheological Behavior ◽  
Oil Content ◽  
Sensory Attributes ◽  
Rheological Parameters ◽  
Low Fat ◽  
Concentric Cylinder ◽  
Rheological Characterization

The effects of ingredients on the sensory evaluation and rheological behavior of two brands of mayonnaise were examined in this work. Mayonnaise samples were examined by Analytical Descriptive Test and Ranking Test of Preference. The rheological parameters were determined at 25°C using a concentric cylinder Brookfield rheometer with a spindle SC4-34. The results showed that standard mayonnaise as opposed to low-fat mayonnaise gained higher grades for most sensory attributes. All samples were found to exhibit non-Newtonian pseudoplastic behavior described by Herschel–Bulkley model. A decrease in the yield stress, viscosity and shear stress with the decrease in oil content was observed in all products, which confirm that the rheological characterization is capable of distinguishing rather well between mayonnaises made with different formulation.

Influence of solid retention time on the rheology of MBR sludge

2007 ◽  
Vol 56 (8) ◽  
pp. 151-159 ◽  
Author(s):  
C. Giordano ◽  
A. Pollice ◽  
G. Laera ◽  
D. Saturno ◽  
G. Mininni
Keyword(s):  
Retention Time ◽  
Apparent Viscosity ◽  
Biomass Concentration ◽  
Rheological Behaviour ◽  
Solid Material ◽  
Design Parameters ◽  
Rheological Characterization ◽  
Solid Retention Time ◽  
The One ◽  
Definition Of

The rheological characterization is of crucial importance in sludge management both for biomass dewatering and stabilization purposes and for the definition of design parameters for sludge handling operations. The sludge retention time (SRT) has a significant influence on biomass properties in biological wastewater treatment systems and in particular in membrane bioreactors (MBR). The aim of this work is to compare the rheological behaviour of the biomass in a membrane bioreactor operated under different SRT. A bench scale MBR was operated for four years under the same conditions except for the SRT, that ranged from 20 days to complete sludge retention. The rheological properties were measured over time and the apparent viscosity was correlated with the concentration of solid material under equilibrium conditions. The three models most commonly adopted for rheological simulations were evaluated and compared in terms of their parameters. Steady state average values of these parameters were related to the equilibrium biomass concentration (MLSS). The models were tested to select the one better fitting the experimental data in terms of Mean Root Square Error (MRSE). The relationship between the apparent viscosity and the shear rate, as a function of solid concentration, was determined and proposed.

scholarly journals Relationship between Rheological Behaviour and Final Structure ofAl2O3and YSZ Foams Produced by Replica

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
S. Y. Gómez ◽  
O. A. Alvarez ◽  
J. A. Escobar ◽  
J. B. Rodrigues Neto ◽  
C. R. Rambo ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Raw Materials ◽  
Rheological Behaviour ◽  
Rheological Parameters ◽  
Ceramic Structure ◽  
Ceramic Foams ◽  
Different Types ◽  
Binder Type ◽  
Ceramic Suspensions ◽  
Ceramic Thickness

Using rheological parameters of ceramic suspensions, it is possible to taylor the structure of the ceramic foams produced by replica. This method consists in the impregnation of a polymeric flexible template (polyurethane foam) with a ceramic suspension (slurry) containing the appropriate additives, followed by burning out organic compounds and additives and sintering the ceramic structure. In this work, ceramic foams were produced by the replica method from Al2O3and 3% Y2O3-ZrO2. Rheological parameters of the ceramic suspensions were investigated to improve the mechanical performance of final structures. Different types and quantities of raw materials were combined in order to select the formulations for ceramic foams. The parameters that have a significant influence on the process are the binder type and the amount of solids. Significant changes on the hysteresis area of the suspensions resulted in a lower density of macrodefects in the material. Likewise, when the shear rate viscosity is enhanced, the thickness of the struts increased proportionally. Lastly, when the hysteresis area magnitude and the ceramic thickness increased, the material with higher uniformity was internally densified, and the stress concentration of the internal defects was smoothed

The Rheological Characterization of the Writing Performance of Carbon Black Gel Ink

2009 ◽  
Vol 66 ◽  
pp. 139-142 ◽  
Author(s):  
Ji Jun Qian ◽  
Ai Ping Chen ◽  
Zhong Xin Liu ◽  
Chun Zhong Li
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Carbon Black ◽  
Rheological Parameters ◽  
Rheological Characterization ◽  
Writing Performance ◽  
Strong Shear ◽  
The Common ◽  
The Relationship

The rheological properties of carbon black gel ink were investigated by measurement the relationship between shear stress and shear rate. The fitting to the common rheological curve of gel ink with Hersegel-Bulkley equation was introduced. And the rheological parameters used to characterize the writing properties of gel ink were proposed. The results indicated that the gel ink system possessed strong shear-thinning ability. And the writing performance of the gel ink could be characterized with rheological parameters comprehensively.

Influence of Fructose and Sucrose on Small and Large Deformation Rheological Behaviour of Heated Amioca Starch Dispersions

2004 ◽  
Vol 10 (1) ◽  
pp. 51-57 ◽  
Author(s):  
D. B. Genovese ◽  
V. M. Acquarone ◽  
K. -S. Youn ◽  
M. A. Rao
Keyword(s):  
Yield Stress ◽  
Large Deformation ◽  
Heating Temperature ◽  
Ageing Time ◽  
Rheological Behaviour ◽  
Angular Frequency ◽  
Rheological Parameters ◽  
Static Yield ◽  
Pasting Temperature ◽  
Dynamic Yield

Effect of sucrose or fructose on the rheological behaviour of gelatinized 5% w/w amioca starch dispersions (GSDs), was studied by small and large deformation rheological techniques. Storage (G0) and loss (G00) moduli as a function of angular frequency (o), and shear stress (s) as a function of shear rate (_) data were obtained on GSDs with: 0, 30 and 60% w/w sugars. Magnitudes of Herschel–Bulkley yield stress (0-HB) were determined from – _ data. Using the vane method, the static yield stress (0s), the dynamic yield stress (0d) and the shear modulus (G) were determined. Effect of pasting temperature and ageing time were also studied by the vane method. Addition of sugars produced an increase in all rheological parameters except 0d, suggesting that sugars increased the strength of the internal bonds or cohesiveness of the GSDs; in general, fructose was slightly more effective than sucrose. Equivalent parameters: G0 and G, and 0-HB and 0s showed good agreement. Decreasing the heating temperature increased G. GSDs with fructose showed a clear increase in 0s and G with ageing time.

Physicochemical and Electro-Rheological Characterization of Kaolinite / CMS / Silicone Oil Fluid

2010 ◽  
Vol 446 ◽  
pp. 33-41
Author(s):  
Thomas Reiss ◽  
Saoussen Laribi ◽  
Jean-Marie Fleureau ◽  
Jean Francois Tassin
Keyword(s):  
Electric Field ◽  
Yield Stress ◽  
Applied Electric Field ◽  
Silicone Oil ◽  
Rheological Behaviour ◽  
Rheological Characterization ◽  
Clay Particles ◽  
Observed Behaviour ◽  
Composite Nature

The aim of this study is to elaborate electro-rheological fluids based on kaolinite. the scientific characterization made it possible the identification of the composite nature and the checking of the intercalation of the polymer among the clay particles The rheological behaviour of the fluid depends on the electric field. A yield stress of the suspensions is observed, which increases with the applied electric field. An interpretation based on the different modes of association between the clay particles is proposed to account qualitatively for the observed behaviour.

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