Patents by Inventor Robert L. Greenawalt

Robert L. Greenawalt has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5989435
    Abstract: Electro-magnetic filter apparatus and method of operating to separate and remove oily magnetic solids from wastewaters. The filter apparatus includes a filter assembly having an electro-magnetic coil that encircles a canister. The canister has an interior space defined by a wall surface and a first perforated baffle spaced apart from a second perforated baffle. The interior space contains a ferromagnetic matrix comprising split ring lock washers. The feed side end portion of the canister communicates with the wastewater source that contains the oily magnetic solids, a wash-water supply, a pressurized air supply and a disposal stream. The discharge side end portion of the canister communicates with a recycling stream, the disposal stream and the wash-water supply.
    Type: Grant
    Filed: January 21, 1998
    Date of Patent: November 23, 1999
    Assignee: Bethlehem Steel Corporation
    Inventors: Stewart T. Herman, Robert L. Greenawalt, Richard W. Faupel
  • Patent number: 5792364
    Abstract: A system and method for disposing of vacuum degasser contaminants which includes adjusting the pH, in a reactor vessel, of a vacuum degasser underflow stream to precipitate lead and zinc into particulate matter. The solids are then concentrated in a thickener to produce an underflow stream that is communicated to a holding vessel to settle. The overflow from the thickener is filtered through a sand filter and discharged to meet applicable NPDES permit limits. Lime is added to the slurry in the holding vessel to further settle the solids, to aid in filtration, and to prevent leaching of lead from the filter cake during TCLP testing. An overlaying supernatant is decanted from the holding vessel and returned to the reactor vessel for further treatment. Limestone is added to the underflow stream. The resulting slurry is dewatered to produce a friable, non-hazardous filtrate cake and a filtrate. The filtrate is directed back to reactor vessel prior to discharge for further treatment.
    Type: Grant
    Filed: April 29, 1997
    Date of Patent: August 11, 1998
    Assignee: Bethlehem Steel Corporation
    Inventors: Stewart T. Herman, Robert L. Greenawalt
  • Patent number: 5766450
    Abstract: Electro-magnetic filter apparatus and method of operating to separate and remove oily magnetic solids from wastewaters. The filter apparatus includes a filter assembly having an electro-magnetic coil that encircles a canister. The canister has an interior space defined by a wall surface and a first perforated baffle spaced apart from a second perforated baffle. The interior space contains a ferromagnetic matrix comprising split ring lock washers. The feed side end portion of the canister communicates with the wastewater source that contains the oily magnetic solids, a wash-water supply, a pressurized air supply and a disposal stream. The discharge side end portion of the canister communicates with a recycling stream, the disposal stream and the wash-water supply.
    Type: Grant
    Filed: September 25, 1996
    Date of Patent: June 16, 1998
    Assignee: Bethlehem Steel Corporation
    Inventors: Stewart T. Herman, Robert L. Greenawalt, Richard W. Faupel