Electrostatic coalescence pdf

Bailes, E. Taylor, Dewatering [30] Z. Yan, S. Li, Y. Yu, X. Zheng, An investigation into the of crude oil emulsions: 1. Rheological behaviour of the crude breaking-down of water-in-oil type emulsions by means of pulsed oil—water interface, Colloids Surf. A 80 — Cottrell, J.

Speed, Separating and collecting particles of one [31] A. Kumar, F. Ansermet, S. Hartland, Influence de la coalescence liquid suspended in another liquid, US Patent , Cottrell, Process for separating and collecting particles of one decanteurs, Can. Taylor, Investigations into the electrical and coalescence [8] P. Bailes, S. Larkai, An experimental investigation into the use behaviour of water-in-crude oil emulsions in high voltage gradients, of high voltage d.

IChemE Colloids Surf. Hano, T. Ohtake, K. Larkai, Liquid phase separation in pulsed d. IChemE 60 2 — Williams, A. Bailey, Changes in the size distribution of a [34] H. Hauertmann, W. Degener, K. Schugerl, Electrostatic coalescence: water-in-oil emulsion due to electric field induced coalescence, IEEE reactor, process control, and important parameters, Sep.

Taylor, Conductivity and coalescence of water-in-crude oil [61] R. Allan, S. Mason, Particle motions in sheared suspensions: emulsions under high electric fields, Inst. Coalescence of liquid drops in electric and shear fields, J. Hirato, K. Koyama, T.

Tanaka, Y. Awakura, H. Majima, [62] D. Sartor, A laboratory investigation of collision efficiencies, Demulsification of water-in-oil emulsion by an electrostatic coalescence and electrical charging of simulated cloud droplets, J. JIM 32 3 — Chen, R. Taylor, [63] I. Harpur, N. Wayth, A. Bailey, M. Thew, T. Williams, O. Dewatering of crude oil emulsions 4. Emulsion resolution by the Urdahl, Destabilisation of water-in-oil emulsions under the influence application of an electric field, Colloids Surf.

Thew, The electrostatic Electrostatics 40—41 — Pearce, The mechanism of the resolution of water-in-oil Conf. Taylor, Theory and practice of electrically enhanced phase IChemE 74 A [65] C. Bezemer, C. Goes, Motion of water droplets of an emulsion in — Larkai, Influence of phase ratio on electrostatic [66] R.

Interfacial properties of the asphaltic 33— Isaacs, R. Chow, Practical aspects of emulsion stability, Adv. Atten, Electrocoalescence of water droplets in an insulating liquid, [68] H. Pohl, Some effects of nonuniform fields on dielectrics, J.

Electrostatics 30 — Chen, J. Maa, Y. Yang, C. Chang, Effects of electrolytes [69] F. Joos, R. Snaddon, On the frequency dependence of and polarity of organic liquids on the coalescence of droplets at electrically enhanced emulsion separation, Chem. Waterman, Electrical coalescers, Chem. Bailes, An electrical model for coalescers that employ pulsed 51— IChemE 73 A — IChemE 69 A pp.

Clift, J. Grace, M. Weber, Bubbles, Drops, and Particles, [72] D. Klingenberg, F. Man, A. Pacek, A. Nienow, Coalescence in dilute — Event — Hill, New York, Rommel, W. Meon, E. Blass, Review: hydrodynamic modeling [74] R. Bird, W. Stewart, E. Lightfoot, Transport Phenomena, of droplet coalescence at liquid—liquid interfaces, Sep. Wiley, New York, Davis, Two charged spherical conductors in a uniform electric [49] S. Friberg, S. Miksis, Shape of a drop in an electric field, Phys.

Fluids 24 11 [50] E. Manev, C. Vassilieff, I. Ivanov, Hydrodynamics of thin — Nishiwaki, K. Adachi, T. Kotaka, Deformation of viscous droplets [51] H. Zhang, O. Basaran, R. Wham, Theoretical prediction of [78] G. Taylor, Disintegration of water drops in an electric field, Proc. A — Rigby, E. Smith, W. Wakeham, G. Maitland, The Forces [80] P. Winslow Jr. Patent 4,, Vrij, Possible mechanism for the spontaneous rupture of thin free [82] F.

Opawale, D. Burgess, Influence of interfacial properties of liquid films, Discuss. Faraday Soc. Colloid [56] A. Kabalnov, Thermodynamic and theoretical aspects of emulsions Interf. Colloid Interf. Hanai, Theory of the dielectric dispersion due to the interfacial [57] G. Bailes, P. Dowling, The production of pulsed E. Mason, Effects of electric fields on coalescence in for electrostatic coalescence, J. Electrostatics 17 3 — Larkai, Polarisation effects in liquid phase [59] A. Brown, C. Abou-Nemeh, M.

Moors, A. Bailes, M. Kalbasi, Charge measurement and leakage for single of the emulsion used in liquid surfactant membranes process of droplets in a liquid—liquid system, J. Electrostatics 10 81— Li, T. Hucal, Electrodes for electrical coalescence [95] M. Fingas, Water-in-oil emulsion formation: a review of physics and of liquid emulsions, US Patent 4,, Urdahl, T. Thew, Electrostatic [96] R.

Nelson Jr. IChemE 74 A — Sadek, C. Hendricks, Electrical coalescence of water droplets [97] S. Puskas, J. Balazs, A. Farkas, I. Regdon, O. Berkesi, I. Dekany, in low-conductivity oils, Ind. Part 1. New aspects of the stability and rheological properties of [90] G. Elton, R. Picknett, The coalescence of aqueous droplets water—crude oil emulsions, Colloids Surf.

Activity B [98] D. Thompson, A. Taylor, D. Graham, Emulsification and — Tadros, Fundamental principles of emulsion rheology and their — A 91 39— Nordvik, J. Simmons, K. Bitting, A. Lewis, T. Benayoune, L. Khezzar, M. Villamagna, M. Whitehead, A. Chattopadhyay, Mobility of [] Y. Sjoblom, A. Christy, Characterization of surfactants at the water-in-oil emulsion interface, J. Sjoblom, O. Hoiland, A. Christy, E. Johansen, [] A.

Omar, S. Desouky, B. Karama, Rheological characteristics Water-in-crude oil emulsion: formation, characterization, and of Saudi crude oil emulsions, J. Petroleum Sci. Colloid Polym. The first part to be encountered by the contaminated fuel is a wire mesh emitting electrode 31 which is equivalent to the perforated metal emitter 16 in FIG.

An annular plastic spacer 32 is provided so as to enable a separation of the electrical elements as to provide an optimum distance for the contaminant particles to be in contact with the electrostatic charging field. The solid contaminants are accumulated in a non-conductive coarse fiberglass The aqueous contaminants are coalesced in a very fine conductively coated, fiberglass collecting mat electrode 34 which has the same capillary activity as cylinder.

A perforated electrically grounded outer plate 35 supports and grounds the fibrous collecting electrode 34 and permits the passage of coalesced contaminants and cleaned fuel. A urethane sponge material 36 can be included to further increase coalesced drop size. It is seen that the coalesced aqueous contaminants can be drained through drain 37 of the coalescent chamber 40 while the clean fuel can go out through outlet A hydrophobic filtering screen 39 such as Teflon coated mesh can be put in the efiluent flow stream to act as a water barrier, preventing the escape of any fine water droplets with the clean fuel.

In an example of operation, when a charge of 10 kilovolts was applied across the cell for 15 minutes all but 4 ppm. The filter bed was AA fiberglass coated with metallic silver and offered a conductive flux path of approximately Mi 0 inch. Obviously many modifications and variations of the present invention are possible in the light of the above teachings.

It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. The combination as defined in claim 1 wherein said first and second electrode means have a planar configuration, said fiberous material of said second electrode means is glass fiber, and said means for disposal of coalesced contaminants is a coalescent chamber with drain means disposed in the lower region thereof.

USA true USA en. Method and device for in-line mass dispersion transfer of a gas flow into a liquid flow. Method and apparatus for centrifugal separation of dispersed phase from a continuous liquid phase. Removing haze from hydrocarbon oil mixture boiling in the lubricating oil range.

USB1 en. USB2 en. EPA1 en. EPB1 en. CAA en. KRB1 en. An AC power source 15 is connected to the AC electrode structure. The AC field region is identified as zone 2. The AC electrode structure is spaced about 60 cm above the interface and may be constructed of flat steel or copper. The AC electrode is preferably a rectangular perforated steel or copper plate arranged horizontally above the interface.

Obviously, other electrical conducting materials can also be used as the AC electrode. A chamber 17 is located in the upper portion of the vessel 5 through which the process fluid flows exiting the vessel.

Within chamber 17 an array of positive and negative DC electrodes 19 and 21, respectively, are mounted. The DC electrodes are composed of vertically mounted, rectangular flat plates arranged in a closely spaced parallel array with the electrodes alternately connected to the positive and negative terminals of a DC power source to produce a high gradient DC field in zone 3 of the dehydrator.

The DC electrodes may also take the form of vertically disposed cylindrical rods alternately connected to the DC power source positive and negative sides to form the desired DC field gradient. In either case the objective of providing a high gradient DC field in zone 3 separated from the AC field in zone 2 of the dehydrator to remove small residual droplets of water from the process flow may be achieved.

A high gradient DC field is beneficial when the drop size is very small and only a small drop population is present. The collisions of small drops are significantly increased as a result of electrical migration velocity of drops in the DC field.

Thus, using separate AC and DC field regions allows an operator to separately adjust the field to properly tune the system for maximum phase separation. The phase separation phenomena are discussed individually hereinbelow.

After passing upward through zone 3 of the dehydrator, the treated oil exits from an outlet at the top of chamber Water is pumped from the bottom of the vessel 5 at a rate which maintains the interface at a constant level.

The drop-interface coalescence occurs in zone 1. The ultimate phase separation can be achieved only when the drops coalesce at the liquid-liquid interface and the drop's content transfers into the bulk water phase.

The capacity of the electrostatic coalescence unit depends on drop-interface coalescence and the liquid-liquid interfacial area available. In order to achieve the maximum drop-interface coalescence, the drop sizes at the interface must be maintained as close as possible to the initial drop size of the feed emulsion. Therefore, the emulsion inlet distributors are designed to be located in the dispersion band and as near as possible to the interface. The emulsion is distributed so a uniform emulsion layer covers an entire bulk liquid-liquid interface.

No wedge-shape emulsion band is formed when the emulsion is evenly distributed over the interface. The phase separation mechanisms of zone 2 are dipole drop-drop coalescence and settling of coalesced drops into the dispersion band or the interface. The drops which are not coalesced at the interface, especially small drops, can be carried upward into zone 2 by an upward flow of the continuous phase.

An AC electric field promotes drop-drop coalescence of these drops until they are sufficiently large to settle at the interface. Dipole drop-drop coalescence occurs in the zones between electrode-interface and electrode-vessel wall. The collisions of drops in zone 2 result from a large drop population and an upward flow velocity of the continuous phase.

The coalescence efficiency of the AC electric field is large, therefore drop sizes in zone 2 are increased rapidly. Electric field gradients of the AC electric field region may be adjusted. The primary phase separation of emulsion is accomplished in the AC electric field region. These droplets coalesce with great difficulty and can be entrained with upward flow of the continuous phase. In order to accomplish a higher degree of phase separation, the separate high gradient DC electric field region zone 3 provides the secondary phase separation.

A high gradient DC electric field is used in this zone. As pointed out above, the high electric field gradient of this zone is accomplished by closely spacing the electrodes. It should be emphasized that the drop sizes and drop population in zone 3 are very small compared with zone 1 and zone 2. The phase separation mechanisms of zone 3 are: collection of drops at the electrodes; drop-drop coalescence; settling of large coalesced drops; and increasing the drop velocity by electrode contact charging.

When the distance between electrodes is small and a high DC electric field gradient is imposed, there is a rapid migration of drops to one of the electrodes. The water droplets in the oil continuous phase have a net positive charge and they will migrate to the negative electrode. The drop-drop coalescence of zone 3 is not effective for phase separation in this zone because the coalescence of two small droplets does not yield a drop sufficiently large to overcome the upward flow of the continuous phase and settle down into zone 2 and zone 1.

In zone 3, only a small drop population and very small drop size are involved; the collisions between these droplets are very small and thus there is a very small drop-drop coalescence frequency. Therefore, the primary separation mechanism in zone 3 is collection of drops at the electrodes. Drop-drop coalescence, settling of large coalesced drops, and drop contact charging are secondary phase separation mechanisms in this zone.

Hydrophillicity treatments of the negative DC electrodes for improved collection is discussed hereinbelow. Since collection of drops at the electrode is a primary phase separation mechanism in zone 3, it is necessary to provide a large electrode surface area. The DC electric field region may be extended vertically to increase the surface area of the electrodes. Vertical extension provides longer droplet residence time. Although the large drops released from the DC electrodes may adhere onto the AC electrode, this phenomenon will not affect the drop-drop coalescence in zone 2 because the water is conductive and does not alter the electric field in zone 1 and zone 2.

The wetting characteristics of a substrate are important factors determining the efficiency of drop adhesion onto the substrate. The important parameters which have to be considered are the three-phase contact angle through the water phase and the surface characteristics of the substrate such as smoothness. In order to achieve a drop collection efficiency of unity, the negative electrodes of the DC field region are made hydrophilic so that the three-phase contact angle approaches zero.