scholarly journals A Comparative Analysis of the Flow Properties between Two Alumina-Based Dry Powders

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Milene Minniti de Campos ◽  
Maria do Carmo Ferreira
Keyword(s):  
Internal Friction ◽  
Moisture Content ◽  
Ceramic Powder ◽  
Morphological Characteristics ◽  
Angle Of Repose ◽  
Wall Friction ◽  
Flow Index ◽  
Alumina Powder ◽  
Flow Properties ◽  
Angle Of Internal Friction

We measured and compared the flow properties of two alumina-based powders. The alumina powder (AP) is irregularly shaped and has a smooth surface and moisture content of 0.16% (d.b.), and the ceramic powder (CP), obtained after atomization in a spray dryer, is spherical and has a rough surface and moisture content of 1.07%. We measured the Hausner ratio (HR), the static angle of repose (AoR), the flow index (FI), the angle of internal friction, and the wall's friction angle. The properties measured using aerated techniques (AoR and HR) demonstrated that AP presents true cohesiveness (and therefore a difficult flow), while CP presents some cohesiveness and its flow might be classified as half way between difficult and easy flow. Their FI values, which were obtained using a nonaerated technique, enable us to classify the alumina as cohesive and the ceramic powder as an easy-flow powder. The large mean diameter and morphological characteristics of CP reduce interparticle forces and improve flowability, in spite of the higher moisture content of their granules. The angles of internal friction and of wall friction were not significantly different when comparing the two powders.

scholarly journals Mechanical properties of potato starch modified by moisture content and addition of lubricant

2014 ◽  
Vol 28 (4) ◽  
pp. 501-509 ◽  
Author(s):  
Mateusz Stasiak ◽  
Marek Molenda ◽  
Józef Horabik ◽  
Peter Mueller ◽  
Ireneusz Opaliński
Keyword(s):  
Mechanical Properties ◽  
Internal Friction ◽  
Moisture Content ◽  
Bulk Density ◽  
Modulus Of Elasticity ◽  
Potato Starch ◽  
Magnesium Stearate ◽  
Wall Friction ◽  
Considerable Influence ◽  
Angle Of Internal Friction

Abstract Laboratory testing was conducted to deliver a set of characteristics of structure and mechanical properties of pure starch and starch with an addition of a lubricant - magnesium stearate. Considerable influence of moisture content of potato starch was found in the case of density, parameters of internal friction, coefficients of wall friction and flowability. Elasticity was found to be strongly influenced by water content of the material. Addition of magnesium stearate affected density and parameters of flowability, internal friction and elasticity. Bulk density increased from 604 to 774 kg m-3 with decrease in moisture content of potato starch from 17 to for 6%. Addition of magnesium stearate resulted in approximately 10% decrease in bulk density. Angle of internal friction obtained for 10 kPa of consolidation stress decreased from 33 to 24º with increase in moisture content, and to approximately 22º with addition of the lubricant. With an increase of moisture content from 6 to 18% and with addition of the lubricant, the modulus of elasticity during loading decreased from approximately 1.0 to 0.1 MPa. Modulus of elasticity during unloading was found in the range from 19 to 42 MPa and increased with increase of moisture content and amount of lubricant.

scholarly journals Microstructure and flow properties of lyophilized mango pulp with maltodextrin

2019 ◽  
Vol 23 (2) ◽  
pp. 133-137 ◽  
Author(s):  
Marcos R. A. Afonso ◽  
Brena K. M. Rodrigues ◽  
José M. C. da Costa ◽  
Ana C. P. Rybka ◽  
Nedio J. Wurlitzer
Keyword(s):  
Internal Friction ◽  
Bulk Density ◽  
Friction Angle ◽  
Amorphous Structure ◽  
Wall Friction ◽  
Flow Index ◽  
Flow Properties ◽  
Freeze Dried ◽  
Mango Pulp ◽  
And Behavior

ABSTRACT The present study had as objective to determine the flow properties and behavior of lyophilized mango pulp powder as a function of different concentrations of maltodextrin. In the samples of the powders contain 5, 10 and 15% of maltodextrin the angle of effective internal friction, wall friction angle, flow index and bulk density were determined. The microstructure was evaluated by scanning electron microscopy. The freeze-dried samples are characterized as having an amorphous structure, and the drying aid used modified the surface of the particles. The flow index was 3.19, 4.28 and 4.53 for samples containing, respectively, 5, 10 and 15% maltodextrin. Increasing the concentration of maltodextrin in the mango pulp decreased the effective angles of internal friction and wall friction. The bulk density of the powders increased with increasing concentration of maltodextrin for the samples containing 5, 10 and 15% of the maltodextrin, being equal to 597.8, 689.8 and 691.3 kg m-3, respectively. Thus, it was concluded that the addition of maltodextrin modified the shape of the particles, decreased segregation, affected the flow properties of the mango powders, facilitating flow and increasing their bulk density.

scholarly journals Flow and Thermal Properties of Stevia Powder

2018 ◽  
Vol 21 (2) ◽  
pp. 51-55 ◽  
Author(s):  
Ajit K. Mahapatra ◽  
Agnes J. Kapsoiyo ◽  
Sierra C. Birmingham ◽  
Daniel Ekefre ◽  
Bipul K. Biswas
Keyword(s):  
Thermal Properties ◽  
Internal Friction ◽  
Polynomial Regression ◽  
Stevia Rebaudiana ◽  
Calorific Value ◽  
Flow Index ◽  
Published Data ◽  
Mean Flow ◽  
Angle Of Internal Friction ◽  
The Mean

Abstract Stevia (Stevia rebaudiana Bertoni) has recently received a lot of attention as a sweetener due to its taste and low calorific value. Flow and thermal properties of foods play a significant role in the quantitative analysis of unit operations in the food industry. However, there are no published data available on flow and thermal properties of stevia powder. Powder Flow Tester and KD2 Pro Thermal Properties Analyzer were used to determine the flow and thermal properties of stevia powder, respectively, at different moisture contents (4.96%, 9.68%, 13.99%, 20.08%, and 25.79%, w.b.). Mean angle of internal friction of stevia powder ranged from 41.13° to 46.3°. The mean effective angle of internal friction ranged from 47.8° to 52.5° and the mean flow index ranged from 0.27 to 0.48. Mean thermal conductivity of stevia powder ranged from 0.091 W·m-2·K-1 to 0.115 W·m-2·K-1. Mean thermal diffusivity ranged from 0.103 mm2·s-1 to 0.121 mm2·s-1 and mean volumetric specific heat ranged from 0.865 MJ·m-3·K-1 to 1.019 MJ·m-3·K-1. Polynomial regression models were developed to predict flow and thermal properties of stevia powder using moisture content of stevia powder.

Moisture Dependent Dynamic Flow Properties of Coconut Flours

2016 ◽  
Vol 12 (6) ◽  
pp. 577-585 ◽  
Author(s):  
M. R. Manikantan ◽  
R. P. Kingsly Ambrose ◽  
Sajid Alavi
Keyword(s):  
Moisture Content ◽  
Normal Stress ◽  
Flow Characteristics ◽  
Coconut Oil ◽  
Friction Angle ◽  
Wall Friction ◽  
Flow Properties ◽  
Dynamic Flow ◽  
Virgin Coconut Oil ◽  
Air Velocity

Abstract The dynamic flow properties of two important coproducts of virgin coconut oil (VCO) i. e. coconut milk residue flour (MRF) and VCO cake flour (CF) were studied. The basic flowability energy of CF was higher than MRF and increased with moisture content. The change in compressibility and shear stress, with applied normal stress and moisture content, indicated that these powders are highly cohesive. For both flours, the energy required to make the powder flow increased with moisture at all experimental air velocity. Moisture did not significantly influence the cohesion and unconfined yield strength of MRF, whereas for CF there was significant effect due to the presence of moisture. The wall friction angle of both the flours increased significantly with moisture and decreased with applied normal stress. The results from this study indicated that, both CF and MRF at around 4.00 % moisture content had better flow characteristics than at higher moisture levels.

scholarly journals MECHANICAL CHARACTERISTICS OF THE RUBBED MAIZE STRAW DURING SCREW CONVEYING

2021 ◽  
pp. 109-118
Author(s):  
Wulantuya ◽  
Wuyuntana ◽  
Hongbo Wang ◽  
Wenbin Guo ◽  
Chunguang Wang ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Internal Friction ◽  
Moisture Content ◽  
Mechanical Characteristics ◽  
Sliding Friction ◽  
Angle Of Repose ◽  
Flow Function ◽  
Coefficient Of Sliding Friction ◽  
Maize Straw ◽  
Internal Friction Coefficient

In order to reduce the power consumption of screw conveyor and to improve the productivity, this study investigated such mechanical characteristics of rubbed maize straw as coefficient of sliding friction, angle of repose, internal friction coefficient, cohesion, flow function value and compressible coefficient with respect to its moisture content and density. An experiment was designed and consists of a sliding friction characteristic test-bed, a direct shear apparatus, a self-made device with adjustable density and compression. The results showed that: the coefficient of sliding friction increases with the increase of moisture content and density; the angle of repose and internal friction coefficient each increases with increasing moisture content respectively; there is no significant effect between the moisture content and the cohesion of rubbed maize straw; the flow function value goes up with the increase of the moisture content; also the increase of the moisture content leads to the increased bulk density due to the reduced materials gap and the increased compression coefficient, which makes it hard to compress. The equation of pressure and density was found, and it is suitable for the analysis of compression characteristic of rubbed maize straw. The research results lay a theoretical foundation and a basis for the further study on mechanical properties of maize straw.

Effect of Glass Fiber on Shear Strength of Soil

2018 ◽  
Vol 775 ◽  
pp. 603-609
Author(s):  
Himadri Shekhar Saha ◽  
Debjit Bhowmik
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Moisture Content ◽  
Glass Fiber ◽  
Water Content ◽  
Soil Samples ◽  
Fiber Content ◽  
Triaxial Tests ◽  
Angle Of Internal Friction ◽  
Increase With Increase

This paper investigates the effect of glass fiber reinforcement on the shear strength properties of the sand clay mixture. The soil samples were prepared by mixing 50% of locally available Barak river sand with 50% of local clay soil. Triaxial tests were conducted on the soil samples containing five different percentage of fiber to know the effect of fiber content on the shear strength of the soil. Unconsolidated Undrained (UU) Triaxial tests were conducted under three different confining pressures for each sample. Samples were prepared with five different values of moisture content considering 2% less than OMC (Optimum Moisture Content), 1% less than OMC, OMC, 1% more than OMC, and 2% more than OMC to study the effect of water content (w) on behavior of fiber reinforced soil. A parametric study has been carried out in this paper to know the effect of different influencing parameters on the cohesion value and angle of internal friction. The results show that the failure stress and angle of internal friction increase with increase in fiber content up to an optimum value then decrease. On the other hand, the cohesion value increases consistently with increase in fiber content. The study also indicates that the peak deviator stress, angle of internal friction and cohesion values increase with increase in water content up to an optimum value which is less than OMC then decrease with further increase in water content.

Characterisation of Titanium Powder Flow, Shear and Bulk Properties Using the FT4 Powder Rheometer

2014 ◽  
Vol 1019 ◽  
pp. 218-224 ◽  
Author(s):  
Silethelwe Chikosha ◽  
Linda M. Mahlatji ◽  
Hilda K. Chikwanda
Keyword(s):  
Particle Size ◽  
Internal Friction ◽  
Fine Powder ◽  
Friction Angle ◽  
Wall Friction ◽  
Flow Shear ◽  
Coarse Powder ◽  
Bulk Properties ◽  
Angle Of Internal Friction ◽  
Powder Rheometer

In order to reliably design and operate different powder processes, an understanding of the dynamic flow, shear and bulk properties of powders is required. Generally, powders are evaluated by several techniques that determine their flow, shear and bulk properties. The techniques can include compression tests, shear tests, angle of repose, flow of powder in a funnel, tapped density and many others. In order to minimize the number of instruments required to characterise the powder and eliminate operator error, automated powder rheometers that can do most of the required tests have been developed. The FT4 powder rheometer is one of these and has found widespread use in the pharmaceutical industry. In this study, the FT4 powder rheometer was used to characterise two metallic titanium powders with different particle sizes, namely CSIR Ti-45μm (Fine Powder) and CSIR Ti +45-180μm (Coarse Powder). Their particle size, particle size distribution, bulk densities, compressibility, cohesion, flowability index, effective angle of internal friction and wall friction angle were determined. Preliminary results of the study indicated that fine powder had a lower bulk density, was more compressible and more cohesive than the coarse powder. The fine powder had a lower flowability index compared to the coarse powder for both the Jenike and Peschl classification. The varying degrees of cohesion of these powders were confirmed by the cohesion values that were higher for the fine powder. The fine powder had a lower angle of internal friction but higher wall friction angle compared to the coarse powder.

scholarly journals Effects of Grinding Corn with Different Moisture Content on Subsequent Particle Size and Flowability

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1372
Author(s):  
Michaela Braun ◽  
Kara Dunmire ◽  
Caitlin Evans ◽  
Charles Stark ◽  
Jason Woodworth ◽  
...  
Keyword(s):  
Particle Size ◽  
Standard Deviation ◽  
Moisture Content ◽  
Angle Of Repose ◽  
Moisture Loss ◽  
Orifice Diameter ◽  
Flow Index ◽  
Screen Size ◽  
Size Standard ◽  
Ground Corn

The objective of this study was to determine the effects of whole-corn moisture and hammermill screen size on subsequent ground corn moisture, particle size and flowability. Treatments were arranged as a 2 × 2 factorial design with two moisture concentrations (14.5 and 16.7%), each ground using 2 hammermill screen sizes (3 mm and 6 mm). Corn was ground using a lab-scale 1.5 HP Bliss Hammermill at three separate timepoints to create three replications per treatment. Ground corn flowability was calculated using angle of repose (AOR), percent compressibility, and critical orifice diameter (COD) measurements to determine the composite flow index (CFI). There was no evidence for a screen size × corn moisture interaction for ground corn moisture content (MC), particle size, standard deviation, or flowability metrics. Grinding corn using a 3 mm screen resulted in decreased (p < 0.041) moisture content compared to corn ground using the 6 mm screen. There was a decrease (p < 0.031) in particle size from the 6 mm screen to the 3 mm, but no evidence of difference was observed for the standard deviation. There was a decrease (p < 0.030) in percent compressibility as screen size increased from 3 mm to 6 mm. Angle of repose tended to decrease (p < 0.056) when corn was ground using a 6 mm screen compared to a 3 mm screen. For the main effects of MC, 16.7% moisture corn had increased (p < 0.001) ground corn MC compared to 14.5%. The 14.5% moisture corn resulted in decreased (p < 0.050) particle size and an increased standard deviation compared to the 16.7% moisture corn. The increased MC of corn increased (p < 0.038) CFI and tended to decrease (p < 0.050) AOR and COD. In conclusion, decreasing hammermill screen size increased moisture loss by 0.55%, decreased corn particle size by 126 µm and resulted in poorer flowability as measured by percent compressibility and AOR. The higher moisture corn increased subsequent particle size by 89 µm and had improved flowability as measured by CFI.

scholarly journals Maltodextrin on the flow properties of green coconut (Cocos nucifera L.) pulp powder

2020 ◽  
Vol 44 ◽  
Author(s):  
Tayla Maria Ramos Araújo ◽  
Michael Douglas Lemos Farias ◽  
Marcos Rodrigues Amorim Afonso ◽  
José Maria Correia da Costa ◽  
Kaliana Sitonio Eça
Keyword(s):  
Cocos Nucifera ◽  
Friction Angle ◽  
Wall Friction ◽  
Flow Index ◽  
Flow Properties ◽  
Irregular Shapes ◽  
Food Powder ◽  
Cohesive Powder ◽  
Powder Particles ◽  
Cocos Nucifera L

ABSTRACT The study of the flow properties and particle surfaces of a food powder is essential for predicting its behaviour during processing and commercialization. The objective of this work was to determine the powder flow properties of lyophilized green coconut pulp with different concentrations of maltodextrin. Samples containing 0, 5, 10 and 15% (m/m) maltodextrin were lyophilized, and the flow index (FI), wall friction angles and densities were determined. The microstructure of the powders was evaluated by scanning electron microscopy (SEM). The samples containing 0 and 5% maltodextrin showed 1.87 FI, classifying them as very cohesive powders, and those containing 10 and 15% cohesive powder showed 2.12 and 2.43 FI, respectively. The powder densities varied from 138.6 to 287.6 kg/m3, and the wall friction angle varied from 15.8 to 39.8°. The powder particles presented irregular shapes and rough surfaces, especially in powders containing 0, 5 and 10% maltodextrin. The powder containing 15% had smoother and less agglomerated surfaces. An increase in the amount of maltodextrin added to the pulp made the particles smoother and denser and improved the fluidity of the powder.

scholarly journals Effect of Adding Mixture of (Concrete Waste and Asphalt Waste) on The Properties of Gypseous Soil

2019 ◽  
Vol 26 (1) ◽  
pp. 20-25
Author(s):  
Adnan Jayed zedan ◽  
Rizgar Ali Hummadi ◽  
Sarah Abdullah Hussein
Keyword(s):  
Internal Friction ◽  
Moisture Content ◽  
Asphalt Mixture ◽  
Optimum Moisture Content ◽  
California Bearing Ratio ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Angle Of Internal Friction ◽  
Density Values ◽  
Gypseous Soil

Gypseous soil which is used is taken from Tikrit city in Salah Aldeen government and specially from Tikrit University from a depth (1.5-2)m, It’s type is sandy gravely with a small percentage of silt and clay while the percentage of gypsum is (34-36)%, The tests on soil is standard proctor compaction, direct shear, collapsibility and California bearing ratio. The number of samples is (70). The effect of adding concrete waste (2, 4, 6 and 8%) and waste of Asphalt mixture (2, 4, 6 and 8) % on dry soil, as well as the effect of mixture of the optimum percentages of both additions on the properties of gypseous soil, is the aim of the study. Adding concrete waste at optimum percentage (6)% causes an increase maximum dry density at (16)% and a decrease in optimum moisture content at (5)%. Whereas adding concrete mixture waste in its optimum percentage (2)% caused a decrease in maximum dry density values with an increase of optimum moisture content, and when adding mixture of optimum percentage of waste, an increase happened in the M.D.D.(14)% with a decrease in O.M.C. at (4)%. Adding the optimum percentage (8) % for both. Value of cohesion increases (100)% when adding concrete waste with an increase in the angle of internal friction (14)% and a decrease in collapsibility in a percentage of (90)%, while adding waste of asphalt mixture shows an increase in cohesion value (112)% with a decrease in the angle of internal friction (2)%and a decrease in collapsibility in a percentage of (90)%, when adding mixture of optimum percentages the value of cohesion increase (108)% with an increase in angle of internal friction (14)%and a decrease in collapsibility in a percentage of (91)%. Values of California Bearing Ratio in dry and soaked condition increases (49)% when adding (8)% of concrete wastes which is the optimum percentage, while adding waste of asphalt mixture causes a decrease in the value of C.B.R. and the optimum percentage is (2)% , but adding optimum percentages mixture of them causes an increase in values of (52)% in dry condition and (53)% in soaked condition.

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