Liquid separation process for suspensions by a pulsating electrical current

A method of dewatering a suspension comprising:

• a. subjecting the suspension to an acoustical field at a frequency and amplitude adapted to cause separation of liquid bound to particles in the suspension, wherein the applying of the acoustical field is at a frequency of 5000-40,000 Hertz and at an amplitude of 0.002 to 0.01 millimeters;
• b. concurrently subjecting the suspension to pulsating D.C. electrical field adapted to cause a migration of liquid and of particles resulting in a portion of the suspension having an increased concentration of particles and another portion having an increased concentration of liquid;
• and
• c. removing liquid from the portion of the suspension having an increased concentration of liquid, whereby the total amount of energy employed for separating a unit of liquid from the suspension is less than would be required by use of a nonpulsating D.C. electrical field to separate the unit of liquid.

A method of dewatering an aqueous suspension comprising:

• a. flowing the suspension into a dewatering zone;
• b. subjecting the suspension to an acoustical field at an amplitude and frequency adapted to separate water bound to particles in the suspension, wherein the applying of the acoustical field is at a frequency of about 5000 to 40,000 Hertz and at an amplitude of about 0.002 to 0.01 millimeters;
• c. concurrently subjecting the suspension to a pulsating D.C. electrical field adapted to cause a migration of particles toward one portion of the zone and to cause a migration of water toward another portion of the zone;
• and
• d. removing water from the portion of the dewatering zone toward which water is migrating, whereby the total amount of energy employed for separating a unit of water from the suspension is less than would be required by use of a nonpulsating D.C. electrical field to separate the unit of water.

A method of dewatering an aqueous suspension in a dewatering chamber with an inlet and discharge outlet, and having two electrodes, one of which is wear permeable, forming opposing walls of the dewatering chamber which method comprises:

• a. flowing the suspension into the dewatering chamber and between the two electrodes;
• b. applying an acoustical field to the suspension at a frequency and amplitude adapted to separate water bound to suspended particles in the suspension, wherein the applying of the acoustical field is at a frequency of about 5,000 to 40,000 Hertz and at an amplitude of about 0.002 to 0.01 millimeters;
• c. applying a pulsating D.C. electrical field concurrently with step b between the two electrodes adapted to cause the suspended particles to migrate away from the water permeable electrode and water toward the water permeable electrode;
• d. concurrently with step c removing water from the suspension through the water permeable electrode;
• and
• e. removing the dewatered suspension from the dewatering chamber;
• whereby the total amount of energy employed for separating a unit of water from the suspension is less than would be required by use of a nonpulsating D.C. electrical field to separate the unit of water.