scholarly journals Effects of Ultrasound on Behavior of Fine Solid Particles in Solid-Liquid Mixture (Classification of Particle Aggregation and Sound Pressure Profiles under Horizontal Irradiation)

2008 ◽  
Vol 3 (5) ◽  
pp. 655-666 ◽  
Author(s):  
Junichi OHTA ◽  
Hiroyuki NAKANO
2007 ◽  
Vol 2 (1) ◽  
pp. 77-87 ◽  
Author(s):  
Junichi OHTA ◽  
Takashi MAKARA ◽  
Seisuke HIROBE

Author(s):  
Yasuhiro Sugimoto ◽  
Tatsuya Haruna ◽  
Keiichi Sato

It is important to separate and collect particles from solid-liquid mixture in order to reduce in environmental load and treatment cost of waste fluid. In this study, we try to separate and collect particles from the mixture by ultrasonic waves with relatively low frequency. In the present report, we use slurry of alumina abrasive as removal particles that use for polish and water jet cutting, etc. The particles are fully stirred in test water and then ultrasonic waves are irradiated with some frequencies. The particles behavior observed by a high-speed video camera is analyzed by a time series image analysis and correlated with sound pressure distribution. Particles flocculate to some layers like white bands that correspond to node of sound pressure after irradiation of ultrasonic wave. It is found that particles begin to move just after ultrasonic wave irradiation and flocculate clearly with the increase in sound pressure.


Author(s):  
Yajing Wang ◽  
Liqun Wu ◽  
Yaxing Wang ◽  
Yafei Fan

A new method of removing waste chips is proposed by focusing on the key factors affecting the processing quality and efficiency of high energy beams. Firstly, a mathematical model has been established to provide the theoretical basis for the separation of solid–liquid suspension under ultrasonic standing wave. Secondly, the distribution of sound field with and without droplet has been simulated. Thirdly, the deformation and movement of droplets are simulated and tested. It is found that the sound pressure around the droplet is greater than the sound pressure in the droplet, which can promote the separation of droplets and provide theoretical support for the ultrasonic suspension separation of droplet; under the interaction of acoustic radiation force, surface tension, adhesion, and static pressure, the droplet is deformed so that the gas fluid around the droplet is concentrated in the center to achieve droplet separation, and the droplet just as a flat ball with a central sag is stably suspended in the acoustic wave node.


2015 ◽  
Vol 754-755 ◽  
pp. 240-244
Author(s):  
M.N. Derman ◽  
Syaza Nabilla Mohd Suhaimi ◽  
Zuraidawani Che Daud

Microwave sintering is new sintering technology method to produce Al alloys. The advantages of this method because of very short sintering time and less production cost compare to conventional sintering. However, the main problems in microwave sintering are required to be controlled sintering time due to rapid sintering mechanism. Therefore the effect of microwave sintering time to PM Aluminium will be studied. The compacted and sintered aluminium powder is placed in a microwave oven at a different period of 5 minutes, 10 minutes, 15 minutes and 20 minutes. Compression of 150 MPa is applied on aluminium powder to form pellets. Palette is shaped to 1cm in diameter and weighs 1g. SiC is placed together with aluminium samples in the microwave for the purpose of absorbing electromagnetic energy and is converted to heat. Results of different period sintering of aluminium pallet production altered physical properties of each sample. For a rapid sintering time, aluminium pallet does not show any binding reaction between powder particles. Whereas, for long microwave sintering period, solid particles phase change into solid-liquid phase caused by the movement and the formation of bonds between particles. Hence, this will be affecting the mechanical properties of the sample material.


2006 ◽  
Author(s):  
Bhagavatula Venkata Ramana Murthy

Fluidized beds are widely used in industries for mixing solid particles with liquids as the solid is vigorously agitated by the liquid passing through the bed and the mixing of the solid ensures that there are practically no temperature gradients in the bed even with exothermic or endothermic reactions (Mixing and the segregation in a liquid fluidized of particles with different sizes and densities", The Canadian Journal of Chemical Engineering, 1988). The violent motion of the solid particles also gives high heat transfer rates to the wall or to cooling tubes immersed in the bed. Because of the fluidity of the solid particles, it is easy to pass solid from one vessel to another. In the present experimental work, the relative density between solid and liquid phases on pressure drop under fluidized condition has been studied using the solid-liquid systems namely, glass beads-water, glass beads-kerosene, plastic beads-kerosene and diamond sugar-kerosene. Pressure drop - liquid velocity and void fraction - liquid velocity relationships have been found for all the mentioned solid-liquid systems under fluidized condition and results have been noted. The effect of the nature of the fluid on the minimum fluidization velocity and the pressure drop has been studied. In addition to the pressure drop studies, mass transfer studies have also been conducted with diamond sugar-water system with and without fluidization and results have been obtained. In addition to these, comparison of bed voidage, pressure drop and minimum fluidization velocity between denser and lighter liquids have been studied and the results have been obtained. Also, the value of rate of mass transfer with fluidization is compared that without fluidization for diamond sugar-water system and the results have been obtained.


2006 ◽  
Vol 11 (6) ◽  
pp. 575-595 ◽  
Author(s):  
L. Fusi ◽  
A. Farina ◽  
D. Ambrosi

The mechanical behavior of a mixture composed by an elastic solid and a fluid that exchange mass is investigated. Both the liquid flow and the solid deformation depend on how the solid phase has increased (diminished) its mass, i.e. on the mass conversion between constituents. The model is developed introducing a decomposition of the solid phase deformation gradient. In particular, exploiting the criterion of maximization of the rate of entropy production, we determine an explicit evolution equation for the so-called growth tensor which involves directly the solid stress tensor. An example of a possible choice of the constitutive functions is also presented.


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