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Bulk properties of fine particulate solids in the industrial practice.
Bógyiová, Csilla ; Krištof, Ondřej (referee) ; Svěrák, Tomáš (advisor)
This thesis focuses on the description of the characteristics and flow properties of powder materials. The study of powder material’s flow properties is demanding and hard. For a correctly designed technologic process it is necessary to know the flow behaviour of powder materials. Measuring is the best way to study flow properties. The aim of this thesis is to acquaintance the instruments which measure flow properties. Theoretical part of the thesis describes particular materials, ring shear tests with Jenike Shear Cell and evaluation using Mohr’s circles. Experiments were performed on two samples from the industrial practice. These samples are instant teas of various flavour. Attention was paid to the influence of humidity on the flowability of the materials. Results demonstrate that surface characteristics and humidity changes the flow behaviour of bulk properties. Consequently it is necessary to pay attention to these factors when technologic process is designed.
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Bulk properties of fine particulate solids as the function of the selected material parameters.
Slanina, Ondřej ; Roman,, Fekete (referee) ; Svěrák, Tomáš (advisor)
The theoretical part of the thesis focuses on the description of particulate materials and their mechanical behaviors with a focus on flow properties. Great emphasis is placed on measuring the shear properties using a Jenike shear machine, on the correct procedure for standardized measurement and evaluation using Mohr's circles. The theoretical part focuses on the characterization of particulate matter using a variety of methods available, such as visual, separation, sedimentation, surface methods and methods of scanning field and flow. The practical part is focused on the determination of flow characteristics and surface finishing of finely ground limestone Omyacarb VA with various grain sizes. The surface was modified using stearic acid and calcium stearate. Attention was paid to the influence of the concentration of surface-regulating substances on the flowability of the material. The flowability of commercially supplied material was compared with lab modified materials and the determination of the theoretical content of stearic acid or calcium stearate was accomplished. Shear properties were measured using the Jenike shear machine. The material was further tested by laser diffraction and SEM with EDS particle surface analysis and elemental surface mapping.
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Bulk properties of fine powders.
Zubek, Piotr ; Roman,, Fekete (referee) ; Svěrák, Tomáš (advisor)
The subject of this thesis is the measurement of flow properties of powder materials. The theoretical part deals with particulate substances in general and describes the basic principles of flow behavior of powder materials. In the theoretical part is a description of the Jenike Shear Tester and Ring Shear Tester. The following section summarizes the Standard Shear Testing Technique. Measurements were carried out on the new apparatus Laboratory of Chemical Engineering. The measurement was selected 5 samples of limestone Omyacarb ® from Omya CZ s.r.o. Individual samples varied in four different particle size distributions and one sample was surface-modified hydrophobic stearic acid. Tests were conducted at 3 levels of the preshear normal stress - 2.5 kPa, 5 kPa and 7.5 kPa. Distribution function of particle size in the material data sheets supplied by the manufacturer were verified using a laser particle size analyzer Sympatec Helos KR purchased in the Materials Research Centre at the Faculty of Chemistry at Brno University of Technology.
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Bulk properties of fine particulate solids in the industrial practice.
Bógyiová, Csilla ; Krištof, Ondřej (referee) ; Svěrák, Tomáš (advisor)
This thesis focuses on the description of the characteristics and flow properties of powder materials. The study of powder material’s flow properties is demanding and hard. For a correctly designed technologic process it is necessary to know the flow behaviour of powder materials. Measuring is the best way to study flow properties. The aim of this thesis is to acquaintance the instruments which measure flow properties. Theoretical part of the thesis describes particular materials, ring shear tests with Jenike Shear Cell and evaluation using Mohr’s circles. Experiments were performed on two samples from the industrial practice. These samples are instant teas of various flavour. Attention was paid to the influence of humidity on the flowability of the materials. Results demonstrate that surface characteristics and humidity changes the flow behaviour of bulk properties. Consequently it is necessary to pay attention to these factors when technologic process is designed.
|
|
|
Bulk properties of fine particulate solids as the function of the selected material parameters.
Slanina, Ondřej ; Roman,, Fekete (referee) ; Svěrák, Tomáš (advisor)
The theoretical part of the thesis focuses on the description of particulate materials and their mechanical behaviors with a focus on flow properties. Great emphasis is placed on measuring the shear properties using a Jenike shear machine, on the correct procedure for standardized measurement and evaluation using Mohr's circles. The theoretical part focuses on the characterization of particulate matter using a variety of methods available, such as visual, separation, sedimentation, surface methods and methods of scanning field and flow. The practical part is focused on the determination of flow characteristics and surface finishing of finely ground limestone Omyacarb VA with various grain sizes. The surface was modified using stearic acid and calcium stearate. Attention was paid to the influence of the concentration of surface-regulating substances on the flowability of the material. The flowability of commercially supplied material was compared with lab modified materials and the determination of the theoretical content of stearic acid or calcium stearate was accomplished. Shear properties were measured using the Jenike shear machine. The material was further tested by laser diffraction and SEM with EDS particle surface analysis and elemental surface mapping.
|
|
|
Bulk properties of fine powders.
Zubek, Piotr ; Roman,, Fekete (referee) ; Svěrák, Tomáš (advisor)
The subject of this thesis is the measurement of flow properties of powder materials. The theoretical part deals with particulate substances in general and describes the basic principles of flow behavior of powder materials. In the theoretical part is a description of the Jenike Shear Tester and Ring Shear Tester. The following section summarizes the Standard Shear Testing Technique. Measurements were carried out on the new apparatus Laboratory of Chemical Engineering. The measurement was selected 5 samples of limestone Omyacarb ® from Omya CZ s.r.o. Individual samples varied in four different particle size distributions and one sample was surface-modified hydrophobic stearic acid. Tests were conducted at 3 levels of the preshear normal stress - 2.5 kPa, 5 kPa and 7.5 kPa. Distribution function of particle size in the material data sheets supplied by the manufacturer were verified using a laser particle size analyzer Sympatec Helos KR purchased in the Materials Research Centre at the Faculty of Chemistry at Brno University of Technology.
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