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 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.