Reduction In Apparent Viscosity Research Articles

Ascorbic acid-mediated reduction of arabinoxylan viscosity through free radical reactions

Arabinoxylan (AX) is a potential natural food additive that can enhance the textural properties of food. However, the addition of ascorbic acid (AA) can easily lead to a decrease in the viscosity of AX, which poses a challenge in the development of AX-rich foods. Therefore, the purpose of this study is to elucidate the mechanisms behind the reduction in AX viscosity in the presence of AA. The results indicated that AA could reduce the apparent viscosity and molecular weight of AX without significantly affecting the monosaccharide composition, suggesting a potential mechanism related to the cleavage of AX glycosidic bonds. Interestingly, free radicals were present in the reaction system, and the generation of free radicals under different conditions was consistent with the reduction in apparent viscosity of AX. Furthermore, the reduction in AX apparent viscosity by AA was influenced by various factors including AA concentration, reaction time, temperature, pH, and metal ions. These findings suggested that the mechanism of AX degradation may be due to AA-induced free radical generation, leading to non-selective attacks on glycosidic bonds. Therefore, this study revealed that the potential mechanism behind the reduction in AX viscosity induced by AA involved the generation of ascorbic acid radicals.

Development of 3D printable stabilized earth-based construction materials using excavated soil: Evaluation of fresh and hardened properties

Soil excavated during construction and demolition can be utilized to reduce the demand for natural sand in 3D printed constructions. This research attempts to systematically develop 3D printable stabilized earth-based materials using excavated soil (clay content of 42.5 %) as 25 % and 50 % replacement of natural sand, and examine their compressive strength, water permeable porosity, and moisture sensitivity. The effectiveness of two binder systems – Ordinary Portland Cement (OPC) and a combination of OPC and ground granulated blast furnace slag (GGBS used to replace 30 % OPC by mass), was investigated. Non-expansive clay in the soil leads to a steeper reduction in apparent viscosity, 12–15 % higher flow retention, and 50–60 % lower plastic viscosity of soil-based mixes, thus contributing to superior extrusion quality at 35–40 mm lower initial flow than OPC-sand and OPC-GGBS-sand mixes. The addition of GGBS, due to its irregular particle morphologies and interlocking effects, further enhances the shape retention of the printed layers by 8–26 % compared to OPC-soil mortars. The structural build-ups in OPC-soil and OPC-GGBS-soil mortars increase with the increase in clay content, which enabled buildability up to a height of 1.2 m compared to only 0.51–0.55 m for OPC-sand and OPC-GGBS-sand mortars. Higher water demand due to the addition of natural clay increases the porosity of 3D printed OPC-soil mortars, thereby lowering compressive strength and increasing moisture sensitivity. However, a blend of OPC and GGBS substantially reduces the moisture sensitivity of the printed mortars at 28-day age, attributed to better stabilization of clay through hydraulic and pozzolanic action of GGBS. 28-day wet compressive strength of 14–25 MPa is obtained for the printed soil-based mixes depending on the soil dosage and loading direction. In summary, the study provides a feasible solution for the 3D printing of stabilized earth structures with lower demand for natural sand and OPC.

Electroosmosis of viscoelastic fluids in pH-sensitive hydrophobic microchannels: Effect of surface charge-dependent slip length

We analytically investigated the electroosmotic flow characteristics of complex viscoelastic liquids within a charged hydrophobic microchannel, considering the pH and salt concentration-dependent surface charge effects in our analysis. We examined the variation of the electric-double layer (EDL) potential field, the surface charge-dependent slip (SCDS) length, the flow field, the viscosity ratio, and both normal and shear stresses in relation to the bulk pH, bulk salt concentration, and Deborah number of the solution. Our current findings indicate that, under strong flow resistance due to increased electrical attraction on counter ions, a highly basic solution with a high EDL potential magnitude results in a significant decrease in the slip length. Neglecting the effect of SCDS leads to an overestimation of flow velocity, with this overprediction being more pronounced for highly basic solutions. This overestimation diminishes as bulk salt concentration increases, particularly when compared to strongly acidic solutions. Furthermore, a noticeable increase in average velocity is observed as the Deborah number rises for highly basic solutions compared to highly acidic ones. This is attributed to the substantial reduction in apparent viscosity caused by the shear-thinning nature of the liquid at higher shear rates, supported by a larger zeta potential modulated strong electrical force for basic solutions. Additionally, we found that the intensity of shear and normal stresses tends to increase with bulk pH, primarily due to the rise in electric body force at higher zeta potential. These results can potentially inform the design and development of a compact, nonmoving electroosmotic pump for transporting biological species with varying physiological properties, such as solution pH. This technology could be applied in subsequent processes involving mixing, separation, flow-focusing for cell sorting, and other related applications.

Influence of pre- or post-electron beam irradiation on heat-moisture treated maize starch for multiscale structure, physicochemical properties and digestibility

Electron beam irradiation (EBI) as a green technological method for starch modification can generate starch-based materials with new functions. This study modified maize starch by heat-moisture treatment (HMT) for 1 h and 3 h, and EBI with various intensities (5 kGy and 10 kGy), and their effects of treatment sequence on the multiscale structure, physicochemical properties and in vitro digestibility were investigated. EBI or HMT alone did not change the granule morphology and crystalline type, but reduced the crystallinity and molecular weight and increased the resistant starch content. HMT alone had no significant effect on the solubility of starch, while EBI led to a considerable increase in the solubility of maize starch. The combined treatment of EBI and HMT aggravated apparent viscosity reduction, and the HMT starch pretreated with EBI had a smaller molecular weight and lower viscosity. In contrast, post-EBI samples had higher solubility and RS content. Primarily, it has excellent potential for producing low-viscosity and high-solubility starch foods.

Application of high-pressure homogenization to steer the technological functionalities of chia fibre-protein concentrate

Chia is an excellent source of healthy constituents (dietary fibre and proteins) with high water holding capacity (WHC) and strong gelling properties, which imply technological challenges for its application in foods, such as leavened bakery products. Therefore, this work explored the potential of high-pressure homogenization (HPH) to steer the technological functionalities (physicochemical, structural and rheological properties) of a chia fibre-protein concentrate (FPC) for food applications. Chia FPC suspensions (5%, w/w) were treated at increasing pressures (up to 150 MPa) and number of cycles (up to 5) to generate a wide range of energy densities delivered to the sample during processing (100–750 MJ m−3). HPH treatments decreased particle size, WHC and oil holding capacity of FPC. WHC of treated samples was 52–70% lower than control. Moreover, rheological measurements on the soluble fraction of homogenised FPC showed a reduction in apparent viscosity and shear-thinning behaviour. These results can be attributed to multiple events occurring during HPH processing. In particular, the mechanical forces suffered by the samples induced the rupture of native structures in smaller fragments in concomitance with biopolymer structure modifications. HPH at energy densities between 300 and 750 MJ m−3 determined a 14–35% increase in soluble dietary fibre (SDF) compared to control, indicating a partial conversion from insoluble to SDF without changes in total dietary fibre. Conformational changes in proteins were also observed. This study suggests that proper selection of HPH energy density represents a strategy to obtain novel promising ingredients rich in dietary fibre and proteins with tailored technological functionalities.

Thixotropic evaluation of a highly-workable and a flowable concrete made with Rice Husk Ash

Thixotropic behaviour of a Highly-Workable Concrete (HWC) and a Flowable Concrete (FC) containing varying volumetric dosages (10%, 15%, and 20%) of Rice Husk Ash (RHA) has been investigated using a coaxial cylinder concrete rheometer. The parameters to evaluate the thixotropic behaviour were RHA dosage and grade of concrete. The experiments showed that concrete exhibits a high degree of thixotropy when proportioned with a binary binder containing RHA. The influence of RHA on thixotropy was more pronounced in the HWC than in the FC. The measured thixotropic indices for the HWC, i.e., initial peak stress, thixotropic index, structuration rate, structure parameter, and reduction in apparent viscosity, increased with the increase in RHA dosage, compared to the control concrete. However, the influence of RHA in the case of the FC on all the thixotropic parameters was not significant. As the concrete grade increased from M − 30 to M − 50 in the HWC, thixotropic parameters in the RHA blended concrete increased significantly compared to the control concrete.

Effect of ultrasonication on carboxyl-functionalized multiwalled carbon nanotubes in fresh and hardened Portland cement pastes

abstract: The effects of chemical and physical methods on multiwalled carbon nanotube (MWCNT) dispersion in Portland cement pastes were investigated. Consistency, rheology, compressive strength, dynamic elastic modulus, flexural strength, water absorption, and void content tests were performed to evaluate these effects. Changes in the rheology of the cement pastes and surfactants resulted in a significant reduction in apparent viscosity and yield strength. Additionally, cement pastes containing carboxyl- functionalized MWCNTs (MWCNT-COOH) and surfactant showed higher compressive strengths at 28 d. However, the ultrasonic dispersion method did not significantly influence the properties of hardened Portland cement compared with Portland cement produced using the non-sonicated aqueous solution.

Triple action of FeCl3-assisted hydrothermal treatment of digested sludge for deep dewatering

In this study, a FeCl3-assisted hydrothermal treatment (HTT) process under mild conditions (90 °C–130 °C) was developed for deep dewatering of anaerobically digested sludge. HTT of sludge at 90 °C–130 °C with 4%–6% Fe3+ ions loading based on total sludge solids followed by mechanical dewatering reduced sludge water content from 82% to 38%–53% and sludge weight by 62%–72%. The treatment increased the flowability of sludge through reduction of apparent viscosity and disintegration of colloidal forces between sludge particles. This study unveiled that FeCl3-assisted HTT process had three mechanisms for improving sludge dewaterability and flowability. The treatment hydrolysed sludge flocs in the presence of Lewis acid FeCl3 and high temperature (90–130 °C). Fe3+ ions also improved dewaterability through the formation of double electric layers and neutralisation of surface negative charges, leading to flocculation of sludge flocs. More importantly, the hydrolysed sludge components produced during HTT process acted as reducing agents and led to in-situ generation of iron oxyhydroxide nanoparticles through reduction-oxidation reactions, further enhancing flocculation/co-precipitation of sludge flocs. The treatment reduced EPS content and changed conformational structures of EPS proteins by breaking down hydrogen bond-maintaining α-helix which led to a loose EPS protein structure and enhanced hydrophobicity and flocculability. Furthermore, the FeCl3-assisted treatment promoted immobilisation of the majority of heavy metals in the sludge matrix through co-precipitation/complexation reactions with iron species and organic/inorganic matters. This indicates that the FeCl3-assisted treatment reduced direct toxicity/bioavailability of the majority of heavy metals and the treated sludge may be suitable for land application. Overall, this study provides new insights into mechanism of FeCl3-assisted HTT process for dewaterability of anaerobically digested sludge and immobilisation of heavy metals.

Extensional flow affecting shear viscosity: Experimental evidence and comparison to models

The effect of extensional flow on apparent shear viscosity has never previously been directly measured nor is it often considered. Here, for the first time, through using a novel flow configuration (two-phase shear response under extensional flow), we have directly measured the effect extensional flow has on the apparent shear viscosity of a viscoelastic polymer solution in a controlled and kinematically mixed manner. We show, via a control transient shear experiment, that the apparent shear viscosity of the solution under mixed deformation depends not only on the shear rate but also on the extension rate and their relative direction: shear thinning being enhanced by parallel and reduced by perpendicular extensional flow, respectively. A 62% reduction in apparent viscosity with parallel extension was seen in this work. We then test the ability of the commonly used Giesekus and Carreau–Yasuda (incorporating generalized shear rate) models to predict the effect of extension rate on apparent shear viscosity against our data. The Giesekus model was found to predict the correct qualitative behavior under both parallel and perpendicular extensional flow, and depending on the fitting parameters, also provided a loosely quantitative agreement. Conversely, the generalized shear rate description does not capture the qualitative behavior, with the most significant errors occurring for perpendicular extension (i.e., expansion) flows. This work emphasizes the rarely noted shortcomings of the latter approach when used for experimental analysis and engineering design when extensional flows are additionally present.

Characterisation, rheological properties and immunomodulatory efficiency of corn silk polysaccharides

SummaryCorn silk polysaccharide (CSP) was isolated by heated 80 °C ethanol 70%. The extracted light (83.70 L*) with a yellowish (13.09 b*) reddish (1.98 a*) CSP had an ash content of 2.53 ± 0.03%. It is mainly composed of seven monosaccharides (xylose 23.64, glucose 16.65, ribose 17.35, galactose 13.64, rhamnose 11.93, arabinose 11.87 and mannose 4.85 mol%) and showed four peaks in 13C NMR correlated to the anomeric carbon of arabinose and/or xylose residues. The thermal characteristics exhibited the breakdown of CSP glycosidic bonds at 321.16 °C. The rheological properties showed that the raising of share rate (γ) caused a reduction in apparent viscosity for all tested concentrations, whilst the elastic G′ and viscous G″ storage moduli of CSP were enhanced by increasing the oscillation frequency. The immunomodulatory effects of CSP on RAW264.7 cells showed a significant (P < 0.05) increase in NO secretion up to a concentration of 80 μg mL−1 from CSP. Additionally, the phagocytosis index and acid phosphatase activity were enhanced (P < 0.05) in a dose‐dependent manner by increasing CSP concentrations.

Synthesis and mechanism analysis of a new oil soluble viscosity reducer for flow improvement of Chenping heavy oil

Oil soluble viscosity reducers have gradually attracted the attention of petrochemical research due to their cleanliness and high efficiency. Considering the high viscosity and non-Newtonian fluid properties of Chenping heavy oil found in China, a series of new oil soluble viscosity reducers with different proportions and molecular weights were prepared by free radical polymerization using octadecyl acrylate, 2-allylphenol and N-methylolacrylamide as monomers. The viscosity reducer was applied to different types of heavy oil and found that it exhibited a better effect on heavy oils with high asphaltene content. The test of rheological behavior of heavy oil with additive was performed at wide range of shear rate (3–90 s−1) and temperature range (30–100 °C). The apparent viscosity reduction rate was up to 70.09%, which was better than the industrially relevant ethylene–vinyl acetate copolymer under the same test condition. In addition, the effect of viscosity reducers on the components of heavy oil and the energy change of the system simulated by molecular dynamics simultaneously was investigated. The consistency of the simulated and experimental results show that the effect of viscosity reduction closely related to the crystallization process of wax and the viscosity reducer can reconstruct the surface structure of asphaltene and diminish the connection of benzene ring.

Acoustophoretic Liquefaction for 3D Printing Ultrahigh-Viscosity Nanoparticle Suspensions.

An acoustic liquefaction approach to enhance the flow of yield stress fluids during Digital Light Processing (DLP)-based 3D printing is reported. This enhanced flow enables processing of ultrahigh-viscosity resins (μapp > 3700 Pa s at shear rates = 0.01 s-1 ) based on silica particles in a silicone photopolymer. Numerical simulations of the acousto-mechanical coupling in the DLP resin feed system at different agitation frequencies predict local resin flow velocities exceeding 100 mm s-1 at acoustic transduction frequencies of 110 s-1 . Under these conditions, highly loaded particle suspensions (weight fractions, ϕ= 0.23) can be printed successfully in complex geometries. Such mechanically reinforced composites possess a tensile toughness 2000% greater than the neat photopolymer. Beyond an increase in processible viscosities, acoustophoretic liquefaction DLP (AL-DLP) creates a transient reduction in apparent viscosity that promotes resin recirculation and decreases viscous adhesion. As a result, acoustophoretic liquefaction Digital Light Processing (AL-DLP) improves the printed feature resolution by more than 25%, increases printable object sizes by over 50 times, and can build parts >3 × faster when compared to conventional methodologies.

Elucidation of steady shear flow properties of β‐glucan solutions under different thermal and environmental conditions by different rheological models

AbstractThe present study was carried out to investigate flow behavior of β‐glucan of hull‐less barley cultivar Lut, as influences of concentrations (0.25, 0.5, 0.75, and 1%); temperatures (5, 25, 45, and 60°C); NaCl and CaCl2 salts; pHs; and sugar. Shear stress data were fitted versus shear rates using the models with yield stress such as Casson, Heinz–Casson, Mizrahi–Berk, Generalized Herschel–Bulkley, Vocaldo, and Schulmann–Haroske–Reher together with general model of power law. Power law model provided the most appropriate fit for flow behavior properties of β‐glucan at various concentrations and temperatures with high R2 and low root mean square error. By increase in temperature, consistency coefficient was decreased and flow behavior index was enhanced. Results showed that consistency coefficient increased nonlinearly along with increase in concentration. The highest dependency of consistency coefficient on temperature was observed at 1% concentration (Ea = 31.4 kJ/mol). Apparent viscosity was decreased at 1% concentration of salts. The reduction of apparent viscosity was sharper for NaCl than CaCl2. The highest value of consistency coefficients and the lowest flow behavior indices were found in pH range of 5–7. Increase in sucrose concentration up to 30% elevated consistency coefficient but had no significant effect on flow behavior index. In general, the results showed that the flow behavior of β‐glucan in different conditions can be well interpreted by most rheological models. β‐glucan can also be introduced to the food industry as a suitable thickener in the variety of food solutions with different physicochemical properties (temperature, pH, and the presence of salts and sugar).Practical ApplicationsResearch in the field of rheological behaviors of food fluids plays critical role in designing the processes, transportation systems (pumps and pipes), heat transfer equipment (heat exchangers and evaporators), and determination of the correlation between sensory and textural properties of foods. Temperature, concentration, and environmental conditions (pH, salt, and sugar) are predicted to have a significant effect on the flow behavior of β‐glucan solution. Evaluation of flow behavior of β‐glucan solutions using rheological models provides a reliable prediction about flow behavior of them under various conditions of processing, production, and storage. Food liquids experience different concentrations, temperatures and pH during production, storage, transportation, distribution, marketing, and so forth. Therefore, modeling and simulating the flow behavior of β‐glucan solutions helps foods containing this dietary fiber (as a hydrocolloid) to easily withstand various environmental and thermal conditions in industrial processes without any problems.

Flow, viscoelastic and masticatory properties of tailor made thickened pea cream for people with swallowing problems

This study evaluated the flow, viscoelastic and masticatory properties of tailor made pea cream using different hydrocolloids, and the potential effect that saliva could have while chewing. The creams thickened with pectin, carboxymethyl cellulose, tara gum and konjac gum showed the weakest internal gel structure with highest values of loss tangent at 1Hz (0.49 ± 0.07), slope of log elastic modulus versus log frequency (0.34 ± 0.05) and maximum capacitance (0.07 ± 0.02 Pa-1). The samples thickened with commercial hydrocolloids were affected the most by the presence of saliva, with a significant reduction in apparent viscosity at 10 s−1, that ranged from 1500 mPas until 11000 mPas. These results demonstrate that it is possible to optimize the structure of thickened pea cream for dysphagia by using, for example, carboxymethyl cellulose, tara gum and konjac gum, because they provide a greater viscous component, and, therefore, a bolus that is more easy to swallow.

Pore-to-Core EOR Upscaling for CO2 Foam for CCUS

SummaryThis paper presents an ongoing CO2–foam upscaling research project that aims to advance CO2–foam technology for accelerating and increasing oil recovery, while reducing operational costs and lessening the carbon footprint left during CO2 enhanced oil recovery (EOR). Laboratory CO2–foam behavior was upscaled to pilot scale in an onshore carbonate reservoir in Texas, USA. Important CO2–foam properties, such as local foam generation, bubble texture, apparent viscosity, and shear–thinning behavior with a nonionic surfactant, were evaluated using pore–to–core upscaling to develop accurate numerical tools for a field–pilot prediction of increased sweep efficiency and CO2 utilization. At pore–scale, high–pressure silicon–wafer micromodels showed in–situ foam generation and stable liquid films over time during no–flow conditions. Intrapore foam bubbles corroborated high apparent foam viscosities measured at core scale. CO2–foam apparent viscosity was measured at different rates (foam–rate scans) and different gas fractions (foam–quality scans) at core scale. The highest mobility reduction (foam apparent viscosity) was observed between 0.60 and 0.70 gas fractions. The maximum foam apparent viscosity was 44.3 (±0.5) mPa·s, 600 times higher than that of pure CO2, compared with the baseline viscosity (reference case, without surfactant), which was 1.7 (±0.6) mPa·s, measured at identical conditions. The CO2–foam showed shear–thinning behavior with approximately 50% reduction in apparent viscosity when the superficial velocity was increased from 1 to 8 ft/D. Strong foam was generated in EOR corefloods at a gas fraction of 0.70, resulting in an apparent viscosity of 39.1 mPa·s. Foam parameters derived from core–scale foam floods were used for numerical upscaling and field–pilot performance assessment.

Flow structure and pressure gradient of extra heavy crude oil solution CO2

The flow pattern, pressure drop gradient and apparent viscosity of extra heavy crude oil solution CO2 (viscosity = 10,821 mPa·s at 50 °C) were studied in the high-temperature and high-pressure experimental loop driven without pump shear. Based on the study of the dissolution characteristics of CO2 in extra heavy crude oil, combined with local sampling, micro-photographing and pressure drop gradient testing, three different flow patterns were identified. As the volume of solution CO2 increases, the flow pattern transition boundary gradually shifts to high pressure. In addition, due to the high viscosity of extra heavy crude oil, the flow pattern is relatively less affected by temperature and flow velocity. Pressure drop gradient was introduced to analyze the flow characteristics of extra heavy crude oil solution CO2. Comparing the pressure drop gradients of extra heavy crude oil solution CO2 under different conditions, it can be seen that the presence of CO2 in the dissolved state is better than the precipitation in the form of microbubbles for viscosity reduction of extra heavy crude oil. As soon as the system pressure drop is near the saturation pressure, pressure drop gradient is found to be the lowest. The foam quality concept was introduced to correlate with the apparent viscosity and viscosity reduction characteristics of the dispersion. The small particle size and large number of microbubbles contribute to the apparent viscosity reduction of the dispersion.

Milk Fat Substitution by Microparticulated Protein in Reduced-fat Cheese Emulsion: The Effects on Stability, Microstructure, Rheological and Sensory Properties.

Fat reduction in the formulation of cheese emulsion causes problems in its flowability and functional characteristics during spray-dried cheese powder production. In order to eliminate these problems, the potential of using microparticulated whey protein (MWP) in cheese emulsions was examined in this study. Reduced-fat white-brined cheese emulsions (RF) with different dry-matters (DM) (15%, 20%, and 25% excluding emulsifying salt) were produced using various MWP concentrations (0%–20% based on cheese DM of emulsion). Their key characteristics were compared to full-fat cheese emulsion (FF). MWP addition had no influence on prevention of the phase separation observed in the instable group (RF 15). The most notable effect of using MWP was a reduction in apparent viscosity of RF which significantly increased by fat reduction. Moreover, increasing the amount of MWP led to a decrease in the values of consistency index and an increase in the values of flow behavior index. On the other hand, using high amounts of MWP made the emulsion more liquid-like compared to full-fat counterpart. MWP utilization also resulted in similar lightness and yellowness parameters in RF as their full-fat counterparts. MWP in RF increased glossiness and flowability scores, while decreased mouth coating scores in sensory analyses. Fat reduction caused a more compact network, while a porous structure similar to FF was observed with MWP addition to RF. In conclusion, MWP showed a good potential for formulation of reduced-fat cheese emulsions with rheological and sensorial characteristics suitable to be used as the feeding liquid in the spray drying process.

Thixotropic Behavior of Oil‐in‐Water Emulsions Stabilized with Ethoxylated Amines at Low Shear Rates

AbstractOil‐in‐water (O/W) emulsification is a lubricating pipeline method based on the reduction of the energy frictional loss produced during viscous flow. The flow behavior of heavy O/W emulsions formulated with nonionic surfactants is described. The effects of pH and salinity of the aqueous phase on droplet diameter, stability, and apparent viscosity of O/W emulsions were evaluated. The low‐shear Couette flow of O/W emulsions displayed intense shear‐thinning and thixotropic behavior. Thixotropy was associated to the droplet deformation energy caused by shear rate changes. The droplet deformation and alignment led to the apparent viscosity reduction compared to the fluid at rest. Thixotropic behavior is supposed to balance between the breakdown and recovery of droplet ordered structures. Emulsion formulation parameters were influenced by the aqueous phase pH, enabling to manage the emulsion properties. The droplet mean diameter of < 18 µm resulted in very stable emulsions.

The Influence of the Microstructure of W/O Emulsion of Waxy Crude Oil on Its Rheology

In this article, the viscosity-temperature characteristics of W/O waxy crude oil emulsion under different microstructures were studied, and the characteristics of the microstructure were described by the analysis of the dispersed phase parameters including the average particle size, the degree of dispersion, and the nonuniformity of average particle size. On this basis, we discuss the effects of temperature, shear rate and the microstructure on the apparent viscosity of Daqing crude oil emulsion. The results showed that with the increasing of stirring speed, the number of droplets and the degree of dispersion phase dispersion increased, average droplet size and nonuniformity of average particle size reduced; the average particle size of the dispersed phase decreased by 0.5 μm, and the abnormal point increased by about 1°C. For emulsions with the same microstructure, as the temperature or shear rate rising, the rate and percentage of the reduction in apparent viscosity decreased. At the same temperature or shear rate, the reduction rate in apparent viscosity increases with the average particle size of dispersed phase decreases, in contrast to the percentage of reduction in apparent viscosity, which revealed a definitive correlation between average particle size of dispersed phase and the apparent viscosity in the non-Newtonian fluid that from 34°;C to 48°;C; the absolute value of Pearson’s correlation coefficient was above 0.8, which was highly negatively correlated; as the temperature rose, the absolute value of Pearson’s correlation coefficient decreased from 0.839 to 0.216.

Prediction of pressure drop for the flow of zinc ore-water suspension in horizontal pipeline

Present study was focused on the flow characteristics of zinc ore water suspension. The solid concentration was varied in the range of 30-60% (by weight). The rheometer is used to study the flow behaviour of slurry suspension. The slurry exhibits Non-Newtonian behaviour at solid concentration of 30%. Whereas at higher solid concentrations slurry shows Bingham flow characteristics. The increase in temperature shows significant effect reduction of apparent viscosity. Fanning equation was used to predict the pressure drop in horizontal pipe. From the results it was noticed the pressure drop was increased with solid concentration and flow velocity.