Modeling of spray deposition: Measurements of particle size, gas velocity, particle velocity, and spray temperature in Gas-Atomized sprays

1990 ◽  
Vol 21 (5) ◽  
pp. 899-912 ◽  
Author(s):  
B. P. Bewlay ◽  
B. Cantor
Keyword(s):  
Particle Size ◽  
Particle Velocity ◽  
Spray Deposition ◽  
Gas Velocity

Penetration Dynamics of Solid Particles into Liquids High-Speed Experimental Results and Modelling

2005 ◽  
Vol 473-474 ◽  
pp. 429-434 ◽  
Author(s):  
Olga Verezub ◽  
György Kaptay ◽  
Tomiharu Matsushita ◽  
Kusuhiro Mukai
Keyword(s):  
Contact Angle ◽  
Particle Size ◽  
Aqueous Solutions ◽  
Particle Velocity ◽  
Weber Number ◽  
High Speed ◽  
Solid Particles ◽  
Bulk Liquid ◽  
Distilled Water ◽  
Critical Weber Number

Penetration of model solid particles (polymer, teflon, nylon, alumina) into transparent model liquids (distilled water and aqueous solutions of KI) were recorded by a high speed (500 frames per second) camera, while the particles were dropped from different heights vertically on the still surface of the liquids. In all cases a cavity has been found to form behind the solid particle, penetrating into the liquid. For each particle/liquid combination the critical dropping height has been measured, above which the particle was able to penetrate into the bulk liquid. Based on this, the critical impact particle velocity, and also the critical Weber number of penetration have been established. The critical Weber number of penetration was modelled as a function of the contact angle, particle size and the ratio of the density of solid particles to the density of the liquid.

scholarly journals Effect of Bed Particle Size on Thermal Performance of a Directly-Irradiated Fluidized Bed Gas Heater

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 967
Author(s):  
Sae Han Park ◽  
Chae Eun Yeo ◽  
Min Ji Lee ◽  
Sung Won Kim
Keyword(s):  
Particle Size ◽  
Fluidized Bed ◽  
Thermal Performance ◽  
Thermal Efficiency ◽  
Gas Velocity ◽  
Bubble Behavior ◽  
Heat Transfer Characteristics ◽  
Maximum Value ◽  
Solar Thermal Collector ◽  
Sic Particle

There is a growing interest in a fluidized bed particle receiver that directly irradiates sunlight to particles in the fluidized bed as a solar thermal collector for heating. Thermal performance of directly-irradiated fluidized bed gas heater is strongly affected by the physical properties of the particles. The effect of SiC particle size on heat transfer characteristics in the solar fluidized bed gas heater (50 mm-ID × 100 mm high) has been determined. The outlet gas temperatures showed a maximum value with increasing gas velocity due to the particles motion by bubble behavior in the bed, and the maximum values were found at 3.6 times of Umf for fine SiC and less than 2.0 times of Umf for coarse SiC. Heat absorption from the receiver increased with increasing gas velocity, showing with maximum 18 W for the fine SiC and 23 W for the coarse SiC at 4.5 times of Umf. The thermal efficiency of the receiver increased with increasing gas velocity, but was affected by the content of finer particles. The maximum thermal efficiency of the receiver was 14% for fine SiC and 20% for coarse SiC within the experimental range, but showing higher for the fine SiC at the same gas velocity. A design consideration was proposed to improve the thermal efficiency of the system.

Particle Velocity Distribution in a Novel Draft Tube-Lifted Gassolid Air Loop Reactor

2011 ◽  
Vol 396-398 ◽  
pp. 639-647
Author(s):  
Zhi Yuan Shen ◽  
Li Jun Yang ◽  
Meng Xi Liu ◽  
Chun Xi Lu ◽  
Xiao Na Liu
Keyword(s):  
Particle Velocity ◽  
Theoretical Basis ◽  
Draft Tube ◽  
Experimental Measurements ◽  
Heterogeneous Structure ◽  
Gas Velocity ◽  
Loop Reactor ◽  
Optical Fiber Probe ◽  
The Common ◽  
Superficial Gas Velocity

The hydrodynamics in a gas-solid draft tube-lifted air-loop reactor (GSALR) was investigated systematically using experimental measurements. To demonstrate the gas-solid flow pattern, the upward particle velocity, downward particle velocity and time-averaged particle velocity in four regions of the GSALR were measured by optical fiber probe under different superficial gas velocities. The experimental results show that the downward particle velocity distributes uniformly along the radius in the four regions, but the radial distributions of upward particle velocity and time-averaged particle velocity are core-annulus or heterogeneous structure in the three regions (distributor affect region, draft tube, gas-solid diffluence region), which have the common feature of aggregative fluidization occurred in normal fluidized beds. The operating condition such as superficial gas velocity in draft tube has different effects on the radial distributions of upward particle velocity, downward particle velocity and time-averaged particle velocity in each region. Analysis of the distributions of upward particle velocity, downward particle velocity and time-averaged particle velocity leads to suggestions regarding optimization of the design and provides further theoretical basis for industry application of GSALR.

Radial Hydrodynamics of High Velocity Gas-Solid Down-Flow Fluidized Beds

2003 ◽  
Author(s):  
Songgeng Li ◽  
Weigang Lin ◽  
Jianzhong Yao
Keyword(s):  
Flow Structure ◽  
Particle Velocity ◽  
Fluidized Beds ◽  
Radial Flow ◽  
Optical Probe ◽  
Circulating Fluidized Beds ◽  
Solid Concentration ◽  
Gas Velocity ◽  
Radial Profiles ◽  
Fiber Optical

Experiments have been carried out in a gas-solids co-current down-flow circulating fluidized beds. The radial profiles of particle velocity and solid concentrations were measured by a fiber optical probe. Local solid flux was calculated based on the measured local particle velocity and solid concentration. The influence of gas velocity and solid recirculation rate on the radial flow structure has been examined. The experimental results show that the radial flow structure at high gas velocity has its own prominent characteristics in comparison with that at low gas velocity.

Relationships between size and velocity for particles within debris flows

2008 ◽  
Vol 45 (12) ◽  
pp. 1778-1783 ◽  
Author(s):  
Adam B. Prochaska ◽  
Paul M. Santi ◽  
Jerry D. Higgins
Keyword(s):  
Particle Size ◽  
Debris Flow ◽  
Particle Velocity ◽  
Video Analysis ◽  
Debris Flows ◽  
Impact Force ◽  
Analysis Software ◽  
Impact Forces ◽  
The Impact ◽  
Current Guidelines

Estimation of the impact forces from boulders within a debris flow is important for the design of structural mitigation elements. Boulder impact force equations are most sensitive to the inputs of particle size and particle velocity. Current guidelines recommend that a design boulder should have a size equal to the depth of flow and a velocity equal to that of the flow. This study used video analysis software to investigate the velocities of different sized particles within debris flows. Particle velocity generally decreased with increasing particle size, but the rate of decrease was found to be dependent on the abilities of particles to rearrange within debris flows.

Numerical Simulation and Experimental Studies for High Gas Velocity Electrostatic Precipitator

2012 ◽  
Vol 472-475 ◽  
pp. 2129-2132
Author(s):  
Cheng Wu Yi ◽  
Yun Qing Zhao ◽  
Rong Jie Yi ◽  
Tian Yin
Keyword(s):  
Particle Size ◽  
Dust Particle ◽  
High Efficiency ◽  
Electrostatic Precipitator ◽  
Collection Efficiency ◽  
Experimental Studies ◽  
Simple Algorithm ◽  
Gas Velocity ◽  
Geometry Model ◽  
Relationship Of

The high gas velocity electrostatic precipitator (HGVESP) is simulated by computational fluid dynamics (CFD) technology. The SIMPLE algorithm is used to calculate and the geometry model is divided by pre-processing software ICEM. The relationship of gas velocity, dust particle size and voltage is examined by FLUENT. The results suggest that with the improvement of applied voltage and dust particle size, collection efficiency increases. The results show that HGVESP with transverse plates can not only have a high efficiency, but also increase treatment capacity, which achieve miniaturization. Then the correctness of the model is verified by experiments.

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