Method of filtering oil from liquids

Claim 5

In a method of filtering, the steps of flowing liquid contaminated with freely suspended oil globules through a filter medium bed of granulated shells of black walnuts (Juglans nigra L.), coalescing at least a portion of the oil globules to form agglomerations consisting essentially of oil, and accumulating at least a portion of the oil agglomerations in the interstices of the filter bed; terminating the liquid flow through the filter medium bed; flowing backwash liquid upwardly through the bed (a) to expand the bed and (b) to remove accumulated contaminants from the filter bed, said black walnut shells having a relatively weak affinity for oil which facilitates the removal of the accumulated contaminant during the backwash liquid flow; terminating the backwash liquid flow; and reinitiating filtration liquid flow through the filter medium bed.

Claim 6

In a method of filtering, the steps of flowing liquid contaminated with freely suspended oil globules through a filter medium bed of granulated shells of black walnuts (Juglans nigra L.), coalescing at least a portion of the oil globules to form agglomerations consisting essentially of oil, and accumulating at least a portion of the oil agglomerations in the interstices of the filter bed; terminating the liquid flow through the filter medium bed; flowing backwash liquid upwardly through the bed (a) to expand the bed and (b) to remove accumulated contaminants from the filter bed, said black walnut shells having a relatively weak affinity for oil which facilitates the removal of the accumulated contaminant during the backwash liquid flow; terminating the backwash liquid flow; and reinitiating filtration liquid flow through the filter medium bed.

Claim 7

In a method of removing oily contaminants from a contaminated water-based liquid, the steps of: flowing liquid contaminated with freely suspended oil particles in excess of that sufficient to surface wet any solid contaminants which might be present through a filter bed of granulated black walnut shells (Juglans nigra L.) within a filter housing; coalescing oil particles during the contaminted liquid flow through the filter bed and independently accumulating coalesced oil contaminants in the interstices of the filter bed during the flow of liquid therethrough, to achieve a clarified effluent; terminating the flow of contaminated liquid after the filter bed has become at least partially saturated with accumulated contaminants; cleaning the filter bed of granulated black walnut shells by (a) injecting diluent liquid into said bed to form a liquidous mixture including filter granules and contaminants; (b) violently agitating the liquidous mixture to dislodge the accumulated contaminants from the filter bed granules; and (c) removing contaminants from the filter bed; and reforming the filter bed of granulated walnut shells for further filtration flow.

Claim 8

In a method of removing oily contaminants from a contaminated water-based liquid, the steps of: flowing liquid contaminated with freely suspended oil particles in excess of that sufficient to surface wet any solid contaminants which might be present through a filter bed of granulated black walnut shells (Juglans nigra L.) within a filter housing; coalescing oil particles during the contaminted liquid flow through the filter bed and independently accumulating coalesced oil contaminants in the interstices of the filter bed during the flow of liquid therethrough, to achieve a clarified effluent; terminating the flow of contaminated liquid after the filter bed has become at least partially saturated with accumulated contaminants; cleaning the filter bed of granulated black walnut shells by (a) injecting diluent liquid into said bed to form a liquidous mixture including filter granules and contaminants; (b) violently agitating the liquidous mixture to dislodge the accumulated contaminants from the filter bed granules; and (c) removing contaminants from the filter bed; and reforming the filter bed of granulated walnut shells for further filtration flow.

Claim 9

The method as defined in claim 4, wherein the cleaning step is further characterized by flowing the liquidous mixture through a flow path which is in part exterior to the filter housing, and withdrawing part of the diluent liquid and contaminants from the liquidous mixture flow through a perforated surface in said flow path.

Claim 10

The method as defined in claim 4, wherein the step of cleaning is further characterized by flowing the agitated liquidous mixture over a perforated element, and withdrawing at least a portion of the diluent liquid and contaminants through said perforate element.

Claim 11

In a method of removing suspended globular oil particles from an aqueous-based liquid, the steps of: flowing the oil-contaminated liquid through a filter media bed consisting essentially of untreated granular black walnut shells; coalescing at least some of the globular oil particles during the liquid flow through the granulated black walnut shells to form larger particles consisting essentially of oil and capable of being entrapped within the interstices of the filter media bed; accumulating at least a portion of the coalesced oil particles in the filter media bed to achieve a clarified liquid effluent; terminating the oil-contaminanted liquid flow after the granular black walnut shells have become at least partially contaminated with oil; flowing a backwash liquid through said bed to remove at least part of the accumulated oil to rejuvenate the bed for further oil separation flow; terminating said backwash flow; and reinitiating oil-contaminanted liquid flow through the bed of granular black walnut shells.

Claim 12

In a method of removing suspended globular oil particles from an aqueous-based liquid, the steps of: flowing the oil-contaminated liquid through a filter media bed consisting essentially of untreated granular black walnut shells; coalescing at least some of the globular oil particles during the liquid flow through the granulated black walnut shells to form larger particles consisting essentially of oil and capable of being entrapped within the interstices of the filter media bed; accumulating at least a portion of the coalesced oil particles in the filter media bed to achieve a clarified liquid effluent; terminating the oil-contaminanted liquid flow after the granular black walnut shells have become at least partially contaminated with oil; flowing a backwash liquid through said bed to remove at least part of the accumulated oil to rejuvenate the bed for further oil separation flow; terminating said backwash flow; and reinitiating oil-contaminanted liquid flow through the bed of granular black walnut shells.

Claim 15

In a method of removing contaminant oil particles from a water-based liquid, including the steps of flowing said liquid though a reusable filter media bed of granulated black walnut shells, terminating said flow after the bed has become at least partially contaminated, regenerating the bed, and reusing the bed for subsequent filtration cycles, wherein the improvement comprises: during liquid flow through the layer (a) coalescing at least a portion of the contaminant oil particles to form larger particles consisting essentially of oil, and (b) accumulating at least a portion of the coalesced oil particles in the interstices of the filter media beds; and regenerating the shells by introducing a backwash liquid into and through said layer to remove at least a portion of the accumulated oil, the black walnut shells having a relatively weak affinity for oil, facilitating regeneration of the bed.

Claim 16

In a method of removing contaminant oil particles from a water-based liquid, including the steps of flowing said liquid though a reusable filter media bed of granulated black walnut shells, terminating said flow after the bed has become at least partially contaminated, regenerating the bed, and reusing the bed for subsequent filtration cycles, wherein the improvement comprises: during liquid flow through the layer (a) coalescing at least a portion of the contaminant oil particles to form larger particles consisting essentially of oil, and (b) accumulating at least a portion of the coalesced oil particles in the interstices of the filter media beds; and regenerating the shells by introducing a backwash liquid into and through said layer to remove at least a portion of the accumulated oil, the black walnut shells having a relatively weak affinity for oil, facilitating regeneration of the bed.