Patents Assigned to Dravo Corporation
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Patent number: 4255089Abstract: Two series connected fans driving a variable throat venturi are controlled by a single flow control feedback loop yet are decoupled by modifying the common flow control signal by separate but complementary piecewise linear characterizations of the flow characteristics of each fan. Both fans are protected from surging and overcurrent by their own differential pressure and current limiting control loops respectively which automatically assume control when conditions warrant. The venturi is controlled by its own differential pressure control loop which is operated to generate the maximum differential pressure allowed by the flow rate without surging the fans.Type: GrantFiled: March 22, 1979Date of Patent: March 10, 1981Assignee: Dravo CorporationInventors: William R. Phillips, Jr., Ronald D. Tate
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Patent number: 4251062Abstract: A process for the ignition of sinter mixtures containing solid fuels and apparatus for carrying out this process. The ignition is effected by means of hot combustion gases which are produced, under certain specified conditions, by the combustion of gaseous or liquid fuel initially in a swirl combustion chamber and then under a hood from where they are suctioned through the sinter mix.Type: GrantFiled: March 23, 1978Date of Patent: February 17, 1981Assignee: Dravo CorporationInventors: Erhard Pobuda, Alois Kilian
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Patent number: 4249722Abstract: A burner for the flash oxidation of particles of metal concentrates has three downwardly directed, concentrically mounted tubes each having a venturi nozzle on the discharge end thereof. Finely divided metal concentrates introduced into the annular space between the inner tube and the intermediate tube are accelerated by high pressure oxygen introduced through the inner tube to substantially the velocity of an oxidizing gas introduced into the annular space between the intermediate tube and the outer tube. Means are provided for adjusting the extent that the nozzles on the ends of the inner tube and intermediate tube extend into the nozzles on the ends of the intermediate and outer tubes respectively.Type: GrantFiled: May 11, 1979Date of Patent: February 10, 1981Assignee: Dravo CorporationInventor: Louis H. Jaquay
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Patent number: 4244528Abstract: A process and apparatus for micronizing solid carbonaceous material and preparing carbon oil mixtures. Micronization is accomplished by projecting particles of a carbonaceous material into the point where a number of fluid streams intersect and by then impacting the particles against a rotating cone. The resulting micronized particles are then separated from the fluid in which they are entrained and are mixed with fuel oil. A preferred fluid for use in this process is a gaseous mixture consisting of about fifty percent steam and fifty percent flue gas.Type: GrantFiled: July 26, 1979Date of Patent: January 13, 1981Assignee: Dravo CorporationInventor: Joseph Vlnaty
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Patent number: 4238120Abstract: A seal for a bulk material circular cooler includes arcuate sections of flat, horizontally disposed rings directed inward from each upper side edge of the wind boxes. Horizontally disposed outwardly directed ring-shaped flanges depending from both arcuate bottom edges of the rotating cooler frame extend outward underneath these arcuate sections. Arcuate sealing strips mounted on the underside of the arcuate sections bear against the upper surface of the ring-shaped flanges to form a sliding seal between the wind boxes and the cooler frame. The arcuate sections are bendable in the vertical direction and the weight of these sections and the sealing strips is sufficient to overcome the overpressure of cooling air bearing against the underside of the arcuate sections to maintain the seal.Type: GrantFiled: July 26, 1979Date of Patent: December 9, 1980Assignee: Dravo CorporationInventor: Gunter Schneider
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Patent number: 4231467Abstract: There is disclosed a backstacker-reclaimer apparatus which includes a frame having a combined stacking and reclaiming boom. A plurality of spaced stacking and reclaiming flights are longitudinally driven about the boom by an endless chain drive. A conveyor is provided which feeds material to be stacked to the lower reach of the boom so that flights traveling along the lower reach may push the material up onto the stack. The material is confined in the lower reach by side skirts which may be raised for a reclaiming operation.Type: GrantFiled: May 24, 1979Date of Patent: November 4, 1980Assignee: Dravo CorporationInventor: Edward E. Cheek
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Patent number: 4227892Abstract: Micronized coal is removed from coal-bearing steam by spraying stabilized petroleum oil into the steam and directing the resultant stream at a separation surface on which a coal-oil slurry is deposited and collected. Apparatus includes conduits which direct the resultant stream downward into a housing and normal to a surface on which the slurry is deposited by impact forces. In additional apparatus disclosed, the resultant stream is directed from a horizontal conduit circumferentially along the interior wall of a horizontally disposed cylindrical chamber at the top of the chamber and the coal-oil slurry deposited on the wall by centrifugal force is collected in a trough situated below a longitudinal slot at the bottom of the chamber. In both types of apparatus, after separation of the slurry the velocity of the steam is reduced to settle out remaining oil droplets and is then discharged to the atmosphere.Type: GrantFiled: December 4, 1978Date of Patent: October 14, 1980Assignee: Dravo CorporationInventor: Joseph Vlnaty
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Patent number: 4222872Abstract: Molybdenum or other heavy metal anions and ferric sulfate are reclaimed from wastewater skimmings, that result from treatment of wastewaters through formation of insoluble heavy metal ferric salts and flotation, by treating the skimmings with aqueous caustic at 150.degree.-225.degree. F. to form a solution of the heavy metal anions and a residual solids fraction, separating the solids and contacting the residual solids with sulfuric acid to produce ferric sulfate.Type: GrantFiled: February 27, 1979Date of Patent: September 16, 1980Assignee: Dravo CorporationInventor: Ernest R. Ramirez
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Patent number: 4222851Abstract: This invention relates to the treatment of a multi-component material to separate and recover the components thereof, and more particularly to the solvent extraction or treatment of waste asphalt shingles to recover, in reusable form, the filler, fiber, granules and like solid components as well as asphalt therefrom.Type: GrantFiled: November 6, 1978Date of Patent: September 16, 1980Assignee: Dravo CorporationInventors: Robert D. Good, deceased, Paul P. Quenin
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Patent number: 4221764Abstract: Horizontal basket extractors with a continuous conveyor with spaced baskets or cells are arranged with traveling splitters movable along the top and/or bottom runs of the conveyor synchronously with the baskets arranged to divert a continuous flow of solids and/or liquids from a preceding basket to a following one, thereby eliminating the intermittent feeding of the material being charged in succession but avoiding passage of the material through the spaces between the baskets.Type: GrantFiled: December 15, 1978Date of Patent: September 9, 1980Assignee: Dravo CorporationInventor: Arthur F. Saxon
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Patent number: 4221341Abstract: A sinter crushing machine having a crushing screen and a crushing roll, the screen having hollow teeth with nozzle means for directing a spray of coolant over the working surfaces thereof and the roll having hollow spikes with nozzle means for directing a spray of coolant, such that the working surfaces of the screen and roll are respectively cooled by a substantially uniform amount of coolant at substantially uniform temperatures.Type: GrantFiled: August 29, 1978Date of Patent: September 9, 1980Assignee: Dravo CorporationInventors: Konrad Schymura, Manfred Schafer
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Patent number: 4219417Abstract: A flow of wastewater is adjusted to near zero streaming potential by injecting a non-coagulant mineral acid or base into the wastewater. The potential is measured in streaming detector units. The thus adjusted flow enters a basin where it is subjected to a decreasing gradient of small bubbles to form and separate off a buoyant floc from which valuable materials are more readily recoverable, a floc of higher solids content, and a floc of lesser relative volume than other systems employing similar manipulative steps.Type: GrantFiled: October 25, 1978Date of Patent: August 26, 1980Assignee: Dravo CorporationInventor: Ernest R. Ramirez
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Patent number: 4219470Abstract: There is disclosed a process for the sequential extraction of carbohydrates and oil from particulate oleaginous seed materials utilizing aqueous alcohols as the solvent to produce a novel protein concentrate.Type: GrantFiled: October 23, 1978Date of Patent: August 26, 1980Assignee: Dravo CorporationInventor: George B. Karnofsky
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Patent number: 4219416Abstract: A process for removal of heavy metals in their anionic state, particularly tungsten and molybdenum, from industrial mining wastewater by chemical precipitation of the heavy metal values, followed by gas flotation.Type: GrantFiled: June 29, 1978Date of Patent: August 26, 1980Assignee: Dravo CorporationInventors: Ernest R. Ramirez, Gopalan Ramadorai
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Patent number: 4217981Abstract: A conveying apparatus having a work portion including two work runs disposed to travel at an angle to each other is disclosed. The apparatus includes means for guiding the work portion of an endless conveyor belt whereby first and second work runs lying at an angle to each other and connected by a downwardly extending loop are provided. The guide means is further arranged such that the discharge end of the first work run lies in a plane above the receiving end of the second work run. Means for driving the conveyor belt, and guide means for guiding the return run of the belt are also provided.Type: GrantFiled: June 6, 1972Date of Patent: August 19, 1980Assignee: Dravo CorporationInventor: Aubrey C. Briggs
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Patent number: 4214987Abstract: In a first stage, a flow of wastewater is adjusted to near zero streaming potential by injecting a mineral acid into the wastewater. The thus adjusted flow enters a basin where it is subjected to a decreasing gradient of small bubbles to form and separate off a first buoyant floc from the flow of wastewater. The flow of wastewater then passes to a second stage. In the second stage, a metal coagulant is injected into the wastewater, and the wastewater and coagulant enter a coagulation cell into which dense quantities of bubbles are supplied. Buoyant composites of particulates, coagulant and bubbles are formed in the cell. These composites leave the cell together with the wastewater flow and enter a second flotation basin where a second buoyant floc is separated off.Type: GrantFiled: October 25, 1978Date of Patent: July 29, 1980Assignee: Dravo CorporationInventor: Ogden A. Clemens
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Patent number: 4211752Abstract: A multi-cell apparatus for the solvent extraction of oils or juices from divided organic material and like operations wherein a circular series of open top cells is radially disposed for rotation about a vertical axis with a bottom door hinged to the lower end of each cell comprised of a perforate bottom panel carried on a rigid frame and which is normally held closed against the lower end of its cell, but which swings downwardly by the removal of support at both the inner and outer ends of the door at a predetermined station in the circle of rotation of the cells for the discharge of spent material in turn from each cell preparatory to the door being again closed.Type: GrantFiled: June 16, 1978Date of Patent: July 8, 1980Assignee: Dravo CorporationInventor: Arthur F. Saxon
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Patent number: 4199352Abstract: A continuous, autogenous process for conversion of nonferrous metal sulfide concentrates to remove metal therefrom wherein oxygen-containing gas is fed to a molten concentrate charge, through fluid shielded nozzles of a substantially horizontal converter, wherein sulfur trioxide is fed along with the oxygen-containing gas, with the sulfur trioxide converted to sulfur dioxide within the converter to absorb heat from the charge and assist in control of the temperature thereof.Type: GrantFiled: December 15, 1978Date of Patent: April 22, 1980Assignee: Dravo CorporationInventor: Louis H. Jaquay
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Patent number: 4194729Abstract: A sintering plant in which sinter exhaust gases and cooling gases are collected in separate gas collecting systems. A cooling gas gas-collecting main is located beneath the lower strand of a sintering belt and is connected to opposite sides of each of the wind boxes underlying the cooling section of the sintering strand by at least two cooling gas connecting pipes, and at least one sinter exhaust gas gas-collecting main is disposed adjacent to said cooling gas gas-collecting main and connected to each of the wind boxes underlying the sintering section. Both the cooling gas gas-collecting main and the sinter exhaust gas gas-collecting main are exhausted through a plurality of gas evacuating fans and flue connecting pipes to a flue.Type: GrantFiled: October 30, 1978Date of Patent: March 25, 1980Assignee: Dravo CorporationInventors: Karl Wacker, Fritz Feigk
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Patent number: 4190005Abstract: Combustion gases from combustion of a coal-in-oil fuel mixture are used as an inert carrier gas in a fluid energy pulverizer used in the formation of the fuel mixture. A portion of the hot combustion gases is separated, cooled and compressed and passed to a heat exchanger where that portion is heated by the remainder of the combustion gases, the hot, pressurized portion led to the fluid energy pulverizer for use as a carrier gas for pulverizing of further coal.Type: GrantFiled: December 15, 1978Date of Patent: February 26, 1980Assignees: COMCO - Dravo Corporation, Electric Fuels CorporationInventors: Donald H. Cookson, Clifford W. McCoy