Abstract: This disclosure relates to a method for filtering suspended oil contaminants from an aqueous-based liquid. The method includes flowing the contaminated liquid through a bed of granulated black walnut shells which have a relatively weak affinity for oil. The suspended oil is coalesced during flow through the filter bed to form globular oil particles that are large enough to become entrapped in the interstices of the filter bed. After a substantial quantity of oil has been accumulated in the filter bed, the bed is rejuvenated by flowing backwash liquid therethrough to provide a high velocity scrubbing to free at least a portion of the accumulated oil from the bed, the shells' weak affinity for oil facilitating such rejuvenation. Next, the bed is reformed and a subsequent filtration cycle is initiated.

Abstract: A filter method and apparatus removes tramp oils and fine particulate contaminants from an electrically conductive liquid coolant which is utilized in metal forming, or other comparable, operations. The disclosed method includes flowing the liquid coolant into a separation vessel having a plurality of alternating, oppositely charged plates. The tramp oils and particulate contaminants have an electrical surface charge and are therefore attracted toward one of the charged plates to effect a contaminant migration. This migration results in an agglomeration of the contaminants, but does not necessarily result in an accumulation of the contaminants on the attracting plate. The other charged plate is simultaneously generating a myriad of gaseous bubbles by electrolysis of the liquid coolant. The generated bubbles entrain at least a portion of the agglomerated contaminants into an upward flow to the liquid surface where those contaminants can be conventionally removed.

Abstract: A method and apparatus reduces the amount of radioactive solids resulting from the filtration of particulate contaminants from liquid in a nuclear reactor plant. A filtration system includes a pre-filter comprising a sheet filter medium through which the reactor liquid passes to remove relatively large particulate contaminants for storage or disposal. The reactor liquid is then passed through a bed of granular filter medium to accumulate substantially all the previously non-filtered contaminants and thereby provide a clarified liquid suitable for reuse in the reactor. Backwash liquid is flowed through the granular filter bed to remove and entrain the accumulated contaminants into a slurry which is received by a reservoir where the slurry is maintained quiescently to settle the contaminants.

Abstract: The disclosed method and apparatus relate to the rejuvenation of a bed of granular filter medium which has accumulated particulate and lint contaminants during filtration flow of dirty liquid. The method first includes the step of agitating the filter bed to break-up contaminants which have become agglomerated. The agitating step includes flowing the filter granules and the contaminants in a liquid mixture slurry from the filter bed housing through a closed flow path and then back to the filter housing. The bed is then at least partially reformed, with the finer particulates and lint being in the upper portion of the bed and the larger particulates being in the lower portion of the bed. Then, the upper portion of the bed is expanded and backwashed to remove the finer particulate contaminants and lint. At the same time, the lower portion of the bed and the heavier contaminants flow in a liquid mixture through a cleaning element to remove those heavier contaminants.