Patents Assigned to Dravo Corporation
  • Patent number: 4180251
    Abstract: An apparatus for recovering lead from worn out electric storage batteries in which finely divided dried battery mud is injected into a stream of air through the veni contracta of a venturi in an air conduit. A reducing gas and oxygen are successively introduced into the stream through apertures in the walls of the conduit communicating with annular chambers in fuel and oxygen manifolds surrounding the conduit in sufficient quantities to maintain a stable reducing flame. The droplets of metallic lead and slag which fall from the reducing flame are collected in a refractory lined chamber and separated in a conventional manner.
    Type: Grant
    Filed: April 24, 1978
    Date of Patent: December 25, 1979
    Assignee: Dravo Corporation
    Inventor: Louis H. Jaquay
  • Patent number: 4179374
    Abstract: Apparatus for the treatment of wastewater has an enclosed unit providing a facultative zone wherein a mixture low in dissolved carbon comprising raw sewage and partially processed sewage undergoes denitrification brought about by faculative organisms contained in the prevailing low oxygen environment. Effluent from the facultative zone is charged into an enclosed columnar oxidation unit where a controlled flow of air or oxygen oxidizes nitrogen compounds present in raw sewage into nitrates. Part of the effluent from this columnar oxidation unit wherein the limited flow of oxygen has been mostly consumed in oxidizing the nitrogen compounds and is low in dissolved oxygen is recycled to the facultative zone and part flows into a columnar denitrification zone wherein anaerobic microorganisms substantially completely remove nitrogen as gas from the nitrates producing an effluent with a low nitrate content. Columnar oxidation units and denitrification units are in essentially deep-bed filters.
    Type: Grant
    Filed: October 18, 1977
    Date of Patent: December 18, 1979
    Assignee: Dravo Corporation
    Inventors: Elton S. Savage, Jeffrey J. Chen
  • Patent number: 4175732
    Abstract: Finely divided particulate material is discharged against the incandescent wall of a rotary furnace through a pipe extending into the open end of the furnace in a position where the material is out of the path of the flame projected into the furnace through the open end and out of the path of the out-flowing gases. The material is retained against the interior wall of the furnace by centrifugal force and, as the material melts, it collects in a pool at the inner end of the furnace. The entrainment of fine particles and their subsequent removal with the exhaust furnace gases is thereby substantially reduced, if not entirely eliminated.
    Type: Grant
    Filed: March 24, 1978
    Date of Patent: November 27, 1979
    Assignee: Dravo Corporation
    Inventor: Louis H. Jaquay
  • Patent number: 4168154
    Abstract: A process for sintering iron ore mixtures containing solid fuels on sintering strands in which uniform sinter is obtained throughout the depth of the charge by igniting the surface of the charge and subsequently treating it with hot gases under a set of defined conditions.
    Type: Grant
    Filed: March 7, 1978
    Date of Patent: September 18, 1979
    Assignee: Dravo Corporation
    Inventors: Fred Cappel, Walter Hastik
  • Patent number: 4164549
    Abstract: A method for scrubbing sulfur dioxide from gaseous streams using a calcium salt-containing aqueous liquor having 250-5000 parts per million of magnesium ion to enable fast and efficient return to operation following a period of interruption of the gaseous flow by adjusting the pH of the liquor to a value between 9.8 and 12.0 during said interruption to convert sulfite ion species in the liquor to solid magnesium hydroxide and prevent oxidation thereof, and adding magnesium-containing lime to the liquor after resumption of the scrubbing process when the pH of the inlet liquor has dropped below 9.8 to the previous operational mode.
    Type: Grant
    Filed: January 30, 1978
    Date of Patent: August 14, 1979
    Assignee: Dravo Corporation
    Inventor: Joseph G. Selmeczi
  • Patent number: 4155749
    Abstract: Non-ferrous metal sulfides are converted to recover metals therefrom in a high speed rotary converter, wherein an oxygen-containing gas is used for said conversion, with sulfur trioxide added to the converter along with the oxygen-containing gas to assist in control of temperatures of the charge during conversion, the sulfur trioxide being reduced to sulfur dioxide within the converter and exhausted therefrom.
    Type: Grant
    Filed: May 31, 1978
    Date of Patent: May 22, 1979
    Assignee: Dravo Corporation
    Inventor: Louis H. Jaquay
  • Patent number: 4144229
    Abstract: There is disclosed a process for the extraction of oil from particulate oleaginous seed materials, such as soy beans, utilizing aqueous alcohols as the solvent to produce a novel flour, particularly a soy flour.
    Type: Grant
    Filed: November 26, 1976
    Date of Patent: March 13, 1979
    Assignee: Dravo Corporation
    Inventor: George B. Karnofsky
  • Patent number: 4133718
    Abstract: Rotation of a first drum member at a preselected speed intimately mixes finely divided agglomerative materials to form a loosely coherent, plastic sticky mass. The tumbling action generated by the rotating drum breaks up the loosely coherent, plastic mass into plastic particles or agglomerates which grow in size as they roll within the first drum member. The formed agglomerates are conveyed by rotation of the first drum member into a second drum member that includes an inlet portion surrounding the outlet portion of the first drum member. The second drum member has a longitudinal axis that is coplanarly aligned with the longitudinal axis of the first drum member and both drum members are independently rotated at preselected peripheral speeds with the angle of inclination of the first drum member being adjustable relative to the second drum member to control the movement of the agglomerates.
    Type: Grant
    Filed: June 23, 1977
    Date of Patent: January 9, 1979
    Assignee: Dravo Corporation
    Inventor: Louis H. Jaquay
  • Patent number: 4126411
    Abstract: The invention concerns a rotating round cooler for the cooling of hot loose material, especially hot iron ore sinter, consisting of a ring-form base plate, which is supported with treadrollers on a circular rail, a holding apparatus fastened to the base plate, a cooling chamber which is fastened movably to the holding device with inner and outer walls permeable to gas, whereby at least the bottom edge of the outer wall is located some distance from the base plate, a horizontal passage to the center of the cooler, a charging apparatus above the cooling chamber, a pick-off above the base plate and in the midst of the cooled material, a drive device for the rotary movement of the cooler, inlet devices for the gaseous cooling medium on the inside of the holding device, as well as blowers for the production of the pressure required for the cooling medium.
    Type: Grant
    Filed: October 18, 1976
    Date of Patent: November 21, 1978
    Assignee: Dravo Corporation
    Inventors: Klaus Moller, Dierk Michel, Hartmut Wolert, Helmut Ernst
  • Patent number: 4125379
    Abstract: There is disclosed an improved rotary extractor assembly comprised of a rotor positioned within a vapor tight vessel and having upper and lower wheel assemblies positioned along the periphery thereof, which wheel assemblies ride on upper and lower track assemblies mounted to the inner surface of the vessel.
    Type: Grant
    Filed: August 25, 1976
    Date of Patent: November 14, 1978
    Assignee: Dravo Corporation
    Inventor: Arthur F. Saxon
  • Patent number: 4113413
    Abstract: A first cylindrical drum member has an inlet portion for receiving a supply of agglomerative materials, such as preheated coal and char. The first drum member has a longitudinal axis and an outlet portion through which the agglomerated product is discharged into the inlet end portion of a second cylindrical drum member. A second drum member is supported for rotation independently of the first drum member in tandem relation therewith and has a longitudinal axis copolanarly aligned with and intersecting the longitudinal axis of the first drum member. A rotary scraper is rotatably positioned within the first drum member in spaced relation to the inner cylindrical wall thereof and has a longitudinal axis spaced from the longitudinal axis of the first drum member. The scraper has a tubular body portion that is rotatably supported adjacent the inlet and outlet portions of the first drum member.
    Type: Grant
    Filed: July 28, 1976
    Date of Patent: September 12, 1978
    Assignee: Dravo Corporation
    Inventors: Arthur Jacob Pietrusza, Harry James Kent
  • Patent number: 4102676
    Abstract: A method and apparatus for recovering lead from worn out electric storage batteries in which finely divided dried battery mud is injected into a stream of air through the veni contracta of a venturi in an air conduit. A reducing gas and oxygen are successively introduced into the stream through apertures in the walls of the conduit communicating with annular chambers in fuel and oxygen manifolds surrounding the conduit in sufficient quantities to maintain a stable reducing flame. The droplets of metallic lead and slag which fall from the reducing flame are collected in a refractory lined chamber and separated in a conventional manner.
    Type: Grant
    Filed: March 25, 1977
    Date of Patent: July 25, 1978
    Assignee: Dravo Corporation
    Inventor: Louis H. Jaquay
  • Patent number: 4094667
    Abstract: Finely divided particulate material is discharged against the incandescent wall of a rotary furnace through a pipe extending into the open end of the furnace in a position where the material is out of the path of the flame projected into the furnace through the open end and out of the path of the outflowing gases. The material is retained against the interior wall of the furnace by centrifugal force and, as the material melts, it collects in a pool at the inner end of the furnace. The entrainment of fine particles and their subsequent removal with the exhaust furnace gases is thereby substantially reduced, if not entirely eliminated.
    Type: Grant
    Filed: January 31, 1977
    Date of Patent: June 13, 1978
    Assignee: Dravo Corporation
    Inventor: Louis H. Jaquay
  • Patent number: 4087334
    Abstract: A first cylindrical drum member having an inlet portion for receiving materials to be treated, such as preheated coal and char includes a longitudinal axis and an outlet portion through which the treated materials are discharged into the inlet end portion of a second cylindrical drum member. The second drum member is independently supported for rotation relative to the first drum member and has a longitudinal axis coplanarly aligned with the longitudinal axis of the first drum member such that the drum members are concentrically positioned in tandem relative. A sealing assembly is connected to the first and second drum members for longitudinal movement with the drum members during expansion and contraction of the drum members as they are subjected to different temperatures.
    Type: Grant
    Filed: October 4, 1976
    Date of Patent: May 2, 1978
    Assignee: Dravo Corporation
    Inventors: Richard Francis Harig, Arthur Jacob Pietrusza, Albert Harry Riebel, Jr., Harry James Kent
  • Patent number: 4086821
    Abstract: There is disclosed a drive assembly for the rotor of a solvent extractor and comprised of drive sprocket, a guide sprocket and a take-up sprocket on which is coursed an endless chain, which assembly is disposed about a portion of the rotor on which a chain angle including drive clips are peripherally mounted such that the chain contacts a segment of the chain angle about the rotor.
    Type: Grant
    Filed: February 16, 1977
    Date of Patent: May 2, 1978
    Assignee: Dravo Corporation
    Inventor: Arthur F. Saxon
  • Patent number: 4082489
    Abstract: A first cylindrical drum member is rotatably supported on a platform assembly and has a longitudinal axis that is coplanarly aligned with the longitudinal axis of a second cylindrical drum member that is supported independently of the first drum member and positioned in tandem relation thereto. The first drum member has an inlet end portion through which a pair of feed screw conveyors extend to supply agglomerative materials, such as preheated coal and char, to the inner portion of the first drum member. An outlet portion of the first drum member extends into the inlet portion of the second drum member. A platform assembly is provided that includes a pair of vertically extending leg portions through which a pair of shafts transversely extend to permit pivoting the first drum member. The longitudinal axes of the respective drum members intersect at the transverse axis formed by the shafts so that the platform assembly is arranged to pivot about the intersection of the respective longitudinal axes.
    Type: Grant
    Filed: July 28, 1976
    Date of Patent: April 4, 1978
    Assignee: Dravo Corporation
    Inventors: Harry James Kent, Arthur Jacob Pietrusza
  • Patent number: 4070625
    Abstract: Apparatus for measuring the distance to and through magnetically permeable materials having a planar surface includes a dipole field generating magnetic field transmitting antenna and a dipole field sensitive receiver antenna. The antennae are displaced from one another in a direction parallel to the planar surface a distance d with the field axis of one antenna, preferably the transmitting antenna, parallel to the planar surface and with the axis of the field of the other antenna intersecting and perpendicular to the axis of the field of the first antenna and substantially perpendicular to the planar surface. With this arrangement, perturbations in the magnetic field caused by the magnetically permeable material induce a signal in the receiver antenna which is proportional to 1/D.sup.3 where D is the distance between the antenna and the planar surface and is of the same order as d.
    Type: Grant
    Filed: September 14, 1976
    Date of Patent: January 24, 1978
    Assignee: Dravo Corporation
    Inventor: Joseph W. Harpster
  • Patent number: 4067727
    Abstract: A process and apparatus for sintering material are described wherein a moist sintered material is passed by a travelling grate through an ignition zone, a sintering zone, and a cooling zone with strand cooling of the sintered material being effected. The sintered material is passed through a purging zone of higher flow rate and lesser area than a subsequent initial cooling zone, followed by a final cooling zone. Cooling air from both the purging zone and the initial cooling zone is heated by the sintered material and removes dust particles therefrom. The resultant dust-laden air from the purging zone is de-dusted by conventional means, and the dust-containing heated air from the initial cooling zone is conducted to the sintering zone and forced downwardly through the moist material in the sintering zone.
    Type: Grant
    Filed: April 1, 1976
    Date of Patent: January 10, 1978
    Assignee: Dravo Corporation
    Inventor: Fred Cappel
  • Patent number: 4065295
    Abstract: A process for controlling the speed of strand sintering machines through utilization of the temperature of collected waste gas as measured in the collector pipe as the controlled variable provides improved response by utilizing as an additional controlled variable the temperature of the waste gases at the windboxes. Either the average temperature of those waste gases that leave the windboxes at a temperature above approximately 100.degree. C. or the location of the burn-through point as determined from the temperature of the waste gases at the windboxes can be used as the additional variable. In the latter case, the temperature of the collected waste gases can be used to automatically control the desired variable in a secondary cascade-type control loop in which the location of the burn-through point is the actual value and the travel speed is the regulated quantity.
    Type: Grant
    Filed: July 29, 1976
    Date of Patent: December 27, 1977
    Assignee: Dravo Corporation
    Inventors: Fred Cappel, Walter Hastik, Georges Fleming, Pierre Hofmann
  • Patent number: 4064050
    Abstract: A nozzleless, strainerless filter bottom includes a first set of blocks laid end-to-end in spaced parallel rows to define elongated channels. Transverse grooves in the lower surface of the first set of blocks provide communication between adjacent channels. A second set of blocks laid end-to-end in spaced rows which are parallel to and overlap the rows of first blocks form covers for the longitudinal channels. Transverse slots in the lower surface of the second set of blocks form with the upper surface of the first set of blocks passages through which filtrate and backwash fluid may pass without clogging. A pair of laterally spaced longitudinal flanges depending from the lower surface of the second set of blocks extend into the lower elongated channels and bear against the adjacent sides of the first set of blocks to prevent lateral displacement of both sets of blocks.
    Type: Grant
    Filed: February 27, 1976
    Date of Patent: December 20, 1977
    Assignee: Dravo Corporation
    Inventors: Donald F. Heaney, Delbert L. Boal