SOLID-LIQUID SEPARATION PROCESS
FOR FINE PARTICLE SUSPENSIONS BY AN
ELECTRIC AND ULTRASONIC FIELD
 Inventors: Harapanahalli S. Muralidhara,
Dublin, Ohio; Bhupendra K. Parekh,
Lexington, Ky.; Nagabhusan
Senapati, Dublin, Ohio
 Assignee: Battelle Memorial Institute,
[ * ] Notice: The portion of the term of this patent subsequent to Dec. 31, 2002 has been disclaimed.
 Appl. No.: 799,529
 Filed: Nov. 19,1985
Related U.S. Application Data
 Continuation-in-part of Ser. No. 622,422, Jun. 20,1984, Pat. No. 4,561,953, which is a continuation-in-part of Ser. No. 504,780, Jun. 16, 1983, abandoned.
 IntCl.4 B01D 13/02
 U.S. CI. 204/182.3; 204/157.42;
204/180.1; 204/301; 210/748
 Field of Search 204/186, 299 R, 300 R,
204/301, 302, 307, 182.3, 180.1, 181.8, 181.9, 188,189,190,191, 157.42, 157.62; 210/785,748
 References Cited
U.S. PATENT DOCUMENTS
4,551,924 11/1985 Candor 204/183.1 X
4,561,953 12/1985 Muralidhara et al 204/182.3
FOREIGN PATENT DOCUMENTS
3142987 12/1978 Japan .
80/00226 2/1980 PCT Int'l Appl. .
Rounsley, Robert R., "Drying in the Presence of an Electrostatic Field", 6/1985, Tappi Journal, pp. 108-112.
Neville C. Lockhart; Sedimentation and Electro-osmotic Dewatering of Coal Washery Slimes, Fuel, vol. 60, (Oct. 1981) pp. 919-923.
H. V. Fairbanks, et al; Acoustic Drying of Coal, IEEE Trans, on Sonics and Ultrasonics, vol. SU-14, No. 4 (Oct. 1967) pp. 175-177.
H. V. Fairbanks, et al; Acoustic Drying of Ultrafine
Coals, Ultrasonics, vol. 8, No. 3 (Jul. 1970) pp. 165-167.
Primary Examiner—Donald R. Valentine
Attorney, Agent, or Firm—Klaus H. Wiesmann
A method of separating a solid-liquid suspension (e.g. an aqueous coal suspension, a suspension of clay in oil) by concurrently subjecting the suspension to the action of a sonic or ultrasonic field and an electrical field so as to remove the liquid from the suspension. The suspension is moved into a solid-liquid separation chamber between opposing electrodes one of which is permeable to the liquid. The sonic or ultrasonic field is then applied to the suspension concurrently with the electrical field, at a frequency and amplitude adapted to cause the liquid to separate from the suspension particles. The concurrently applied electrical field between the electrodes causes the particles to migrate away from the permeable electrode and liquid to migrate toward the permeable electrode. The liquid is then removed through the permeable electrode. The method requires less energy to remove a unit of liquid, has a faster rate of liquid removal and achieves a lower liquid content than if only an electrical field or acoustical field were used separately or in sequence.
35 Claims, 4 Drawing Sheets