Abstract: Beads for use in beds in electrostatic separators for the separation of suspended particles from hydrocarbon oils. Electrostatic separators employing a bed of these beads have the capacity to remove as much as 99 weight percent of contaminating particles, such as catalyst fines, from various oil fractions to levels of less than 100 parts per million and even less than 5 ppm. A method and apparatus for purifying various FCC oils using these beads is also provided.

Abstract: A filter for separating finely divided solid particles that may be electrically conducting from electrically nonconducting liquids has means for directing the liquid to be filtered in a radial flow pattern through a filter bed of glass beads to which a high-voltage gradient is applied. A central tubular electrode that serves as a conduit for the liquid extends longitudinally through the filter bed within a concentric cylindrical outer electrode spaced between the central electrode and the casing wall of the filter. After filtering until the electrical current through the filter bed exceeds a predetermined maximum, the voltage gradient is discontinued and the filter backflushed by flowing liquid upwardly through the filter at a rate that expands the filter and causes movement of the beads relative to one another and to the cylindrical outer electrode to remove deposited solids from the beads and from the electrode.

Abstract: A process for separating finely divided, electrically conductive materials from hot liquid hydrocarbons. The process is particularly valuable in the treatment of a liquid hydrocarbon feed stock for a fixed bed catalytic process such as hydrodesulfurization of gas oils or heavier petroleum fractions, or for hydrocracking. The feed stock is made to flow longitudinally through a bed of spherical glass particles between electrodes. A voltage gradient of 5 to 25 kv per inch is applied to the electrodes. Periodically the filter is cleaned by backflushing with filtered product. The backflush liquid and entrained solids are delivered into a thickener consisting of a hollow vessel having a pair of vertical electrodes between which the backflush liquid is passed downwardly. Suspended particles aggregate and rapidly settle from the liquid.