Effect of Electric Fields on Mass Transfer to Droplets PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Effect of Electric Fields on Mass Transfer to Droplets PDF full book. Access full book title Effect of Electric Fields on Mass Transfer to Droplets by . Download full books in PDF and EPUB format.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 9
Get Book Here
Book Description
During the six year funding period, the effects of a direct and alternating field upon single drop hydrodynamics and mass transfer were evaluated both experimentally and theoretically. Direct current field effects upon drop size, velocity and mass transfer rates were also observed for multiple drops formed in a three stage sieve tray column. Drop size, velocity, and mass transfer rates were measured experimentally and compared to simple models for direct current electric fields. Agreement between theory and experiment was found for drop charge, size, and velocity. Drop mass transfer coefficients were substantially larger than theoretical predictions while extraction efficiencies were moderately higher. Drop distortion and oscillation were observed and are thought to result in the experimentally observed higher values. For alternating current fields, drop flow streamlines and oscillations were measured and found to compare well with predictions from a solved mathematical model. In addition, equipment was constructed to determine mass transfer rates to oscillating drops. Concentration profiles in still and oscillating drops were measured and qualitatively compared to theoretical predictions.
Author: Lance Tickner
Publisher:
ISBN:
Category : Drops
Languages : en
Pages : 170
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 26
Get Book Here
Book Description
A series of mass transfer studies were conducted for the extraction of solute from droplets falling in an electric field. The experiments were planned such that the dispersed phase resistance was controlling. In one series of experiments single drops were formed from a charged nozzle and allowed to fall through a continuous, dielectric phase. The drop size and velocity were correlated by means of a simple force balance. Drop mass transfer coefficients were calculated for the drop free fall period and were compared to predictions based upon literature correlations for an oscillating droplet in-the absence of an electric field. Droplet size and velocity were approximately predicted by a staple force balance whereas the mass transfer coefficient was approximately 25--250% higher than that predicted. Droplet extraction efficiencies Increased about 20--30% in the presence of electric fields up to 2 kv/cm. For the same field, the drop diameter decreased 30--50% and the terminal velocity increased by up to 50%. The enhancements for the toluene-water system can be ascribed to increases in terminal velocity and decreases in drop diameter. The mass transfer model for freely falling drops proposed by Skelland and Wellek roughly predicts the moderate mass transfer efficiency increases (about 18% at 1 kv/cm) for the toluene water system but failed to predict the increases (about 25% at 0.5 kv/cm) for the heptane furfural system. The second series of experiments involved the formation of a swarm of droplets In a three stage sieve tray column. In a separate series of experiments. the effect of the electric field upon mass transfer from drops exhibiting interfacial turbulence was evaluated.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 26
Get Book Here
Book Description
A series of mass transfer studies were conducted for the extraction of solute from droplets falling in an electric field. The experiments were planned such that the dispersed phase resistance was controlling. In one series of experiments single drops were formed from a charged nozzle and allowed to fall through a continuous, dielectric phase. The drop size and velocity were correlated by means of a simple force balance. Drop mass transfer coefficients were calculated for the drop free fall period and were compared to predictions based upon literature correlations for an oscillating droplet in-the absence of an electric field. Droplet size and velocity were approximately predicted by a staple force balance whereas the mass transfer coefficient was approximately 25--250% higher than that predicted. Droplet extraction efficiencies Increased about 20--30% in the presence of electric fields up to 2 kv/cm. For the same field, the drop diameter decreased 30--50% and the terminal velocity increased by up to 50%. The enhancements for the toluene-water system can be ascribed to increases in terminal velocity and decreases in drop diameter. The mass transfer model for freely falling drops proposed by Skelland and Wellek roughly predicts the moderate mass transfer efficiency increases (about 18% at 1 kv/cm) for the toluene water system but failed to predict the increases (about 25% at 0.5 kv/cm) for the heptane furfural system. The second series of experiments involved the formation of a swarm of droplets In a three stage sieve tray column. In a separate series of experiments. the effect of the electric field upon mass transfer from drops exhibiting interfacial turbulence was evaluated.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 7
Get Book Here
Book Description
In certain cases droplet direct contact heat transfer rates can be significantly enhanced by the application of an alternating electric field. This field can produce shape oscillations in a droplet which will enhance mixing. The theoretical evaluation of the effect of the interaction of the field with drop charge on the hydrodynamics has been completed for small amplitude oscillations. Previous work with a zero order perturbation method was followed up with a first order perturbation method to evaluate the effect of drop distortion on drop charge and field distribution. The first order perturbation results show secondary drop oscillations of four modes and two frequencies in each mode. The most significant secondary oscillation has the same mode and frequency as the second mode oscillation predicted from the first order perturbation work. The resonant frequency of all oscillations decrease with increasing electric field strength and drop charge. Work is currently underway to evaluate the heat transfer enhancement from an applied alternating electric field.
Author: Thomas Edward Carleson
Publisher:
ISBN:
Category : Drops
Languages : en
Pages : 482
Get Book Here
Book Description
Author: Loto Shen-lun Chang
Publisher:
ISBN:
Category : Drops
Languages : en
Pages : 268
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 7
Get Book Here
Book Description
In certain cases droplet direct contact heat transfer rates can be significantly enhanced by the application of an alternating electric field. This field can produce shape oscillations in a droplet which will enhance mixing. The theoretical evaluation of the effect of the interaction of the field with drop charge on the hydrodynamics has been completed for small amplitude oscillations. Previous work with a zero order perturbation method was followed up with a first order perturbation method to evaluate the effect of drop distortion on drop charge and field distribution. The first order perturbation results show secondary drop oscillations of four modes and two frequencies in each mode. The most significant secondary oscillation has the same mode and frequency as the second mode oscillation predicted from the first order perturbation work. The resonant frequency of all oscillations decrease with increasing electric field strength and drop charge. Work is currently underway to evaluate the heat transfer enhancement from an applied alternating electric field.
Author: Satwindar S. Sadhal
Publisher: Springer Science & Business Media
ISBN: 1461240220
Category : Science
Languages : en
Pages : 528
Get Book Here
Book Description
Fluid flows that transfer heat and mass often involve drops and bubbles, particularly if there are changes of phase in the fluid in the formation or condensation of steam, for example. Such flows pose problems for the chemical and mechanical engineer significantly different from those posed by single-phase flows. This book reviews the current state of the field and will serve as a reference for researchers, engineers, teachers, and students concerned with transport phenomena. It begins with a review of the basics of fluid flow and a discussion of the shapes and sizes of fluid particles and the factors that determine these. The discussion then turns to flows at low Reynolds numbers, including effects due to phase changes or to large radial inertia. Flows at intermediate and high Reynolds numbers are treated from a numerical perspective, with reference to experimental results. The next chapter considers the effects of solid walls on fluid particles, treating both the statics and dynamics of the particle-wall interaction and the effects of phase changes at a solid wall. This is followed by a discussion of the formation and breakup of drops and bubbles, both with and without phase changes. The last two chapters discuss compound drops and bubbles, primarily in three-phase systems, and special topics, such as transport in an electric field.
