Patents Assigned to Envirotech Corporation
  • Patent number: 4364827
    Abstract: A device for moving filter plates from one end of a filter press to the other end, includes carriages which selectively couple to each of the plates and which are driven to slide along the frame members of the press by a hydraulic motor. A control means is provided to control the operation of the hydraulic motor.
    Type: Grant
    Filed: December 28, 1979
    Date of Patent: December 21, 1982
    Assignee: Envirotech Corporation
    Inventor: Murray M. Guttman
  • Patent number: 4364834
    Abstract: A rotary sedimentation apparatus (10), such as a clarifier or thickener, includes a conventional rake arm structure (26, 28, 30) adapted to urge sedimented sludge toward the center of the bottom wall of the apparatus and a centrally mounted drive and lift unit (24) adapted to rotate the rake arm structure. The lifting unit includes an inner cage (84) that is adapted to rotate with the rake arms but to remain at the same elevation when the rake arms are lifted. An improved scum skimming mechanism (12) includes a flat elongate inner blade 40 that is connected by two cables (66 and 68) to the inner cage (84) so that the inner blade remains partially submerged at the liquid level, even though the rake arm structure may be raised. The inner blade is vertically slideably mounted to the upper end of the support frame (50) that extends upwardly from the outer end of a rake arm (30).
    Type: Grant
    Filed: November 10, 1981
    Date of Patent: December 21, 1982
    Assignee: Envirotech Corporation
    Inventor: Walter G. Wawro
  • Patent number: 4359376
    Abstract: A system and process are provided for recovering copper from a contaminated copper-bearing source such as copper smelter flue dust. The copper-bearing source is leached in an acidic solution to produce a liquor containing dissolved copper and dissolved contaminants. Simple copper sulfides are precipitated from the liquor by reacting the liquor with chalcopyrite and sulfur dioxide. Copper is recovered from the precipitated sulfides.A novel process is provided for precipitating simple copper sulfides from a solution containing both dissolved copper and dissolved contaminants. The solution is combined with precipitation product such that substantially all ferric iron contained in the solution is reduced to ferrous iron. The ferric-free solution is reacted with chalcopyrite solids and sulfur dioxide to precipitate the dissolved copper as simple copper sulfides.
    Type: Grant
    Filed: May 11, 1981
    Date of Patent: November 16, 1982
    Assignee: Envirotech Corporation
    Inventors: Frank A. Baczek, Bruce C. Wojcik, Alexander A. Jueschke, Daniel M. Lewis, Jack C. Otto, Lawrence L. Tuttle
  • Patent number: 4342638
    Abstract: An apparatus arrangement and method of operation for treatment of the residue from a coal liquifaction and hydrogenation reactor, which residue contains 5% to 10% solids and is at elevated temperature (f.i. above 700.degree. F.) and pressure of 150-200 psi. Said apparatus comprising a continuous pressure precoat filter sealed against pressure loss, a sealed repulper associated with said pressure filter for repulping filter cake in relatively cooler solvent while maintaining the pressure thereon at about 150-200 lbs/in..sup.2 to yield a slurry, then utilizing the pressure to force the slurry into and through a second pressure filter wherein to effect liquid solids separation; and separately discharging the filtrate and cake from the second filter.
    Type: Grant
    Filed: December 30, 1980
    Date of Patent: August 3, 1982
    Assignee: Envirotech Corporation
    Inventor: Donald A. Dahlstrom
  • Patent number: 4336139
    Abstract: A machine for filtering slurry includes a frame with two drums mounted to said frame for rotation and spaced apart from one another. An endless, perforated drainage belt is disposed around the two drums to define a substantially horizontal drainage surface on the top of the drainage belt. A vacuum pan is located below the drainage surface to apply vacuum to material on the drainage surface, and a raising and lowering system is coupled to the vacuum pan to selectively support the vacuum pan in sealing engagement with the drainage belt and to selectively lower the vacuum pan away from the drainage belt.
    Type: Grant
    Filed: November 24, 1980
    Date of Patent: June 22, 1982
    Assignee: Envirotech Corporation
    Inventors: Max A. Mueller, Dirk Vandertoolen, Gerald Minear
  • Patent number: 4324116
    Abstract: A machine and process for washing paper stock pulp and other vacuum-filterable materials includes a wash drum mounted in a tank. Two endless filter belts are trained to pass around the wash drum and through wash liquid contained in the tank. A mat of pulp is formed between the two endless filter belts and carried on the wash drum and through the tank for washing therein. Wash liquor is pulled by vacuum through the pulp mat as it travels under the drum thereby washing the pulp mat. After the pulp has been washed it is removed from between the two belts.
    Type: Grant
    Filed: April 21, 1980
    Date of Patent: April 13, 1982
    Assignee: Envirotech Corporation
    Inventor: Steven S. Davis
  • Patent number: 4304666
    Abstract: A system is provided for treating spent geothermal brine to remove silica. The process includes introducing the brine into the reaction zone of a reactor-clarifier and allowing the brine to flow therefrom into the clarification zone of the reactor-clarifier. In the clarification zone, particles settle from the brine and are urged to the center of the tank beneath the reaction zone, and the settled particles are drawn upwardly into the reaction zone by an impeller. The particles mix with the brine in the reaction zone to form a substantially uniform distribution therein to provide nuclei for silica precipitation from the brine. A stream of sludge is removed from the bottom of the reactor-clarifier and disposed of.
    Type: Grant
    Filed: May 1, 1980
    Date of Patent: December 8, 1981
    Assignee: Envirotech Corporation
    Inventor: Robert H. Van Note
  • Patent number: 4303516
    Abstract: There is provided a system for treating wastewater having a tank and a partition mounted in the tank to define an endless circuitous channel. An aerator and impeller is mounted in the tank to cause the liquid to flow through the channel. A clarifier is disposed in the channel and has a liquid outlet in its upper portion.
    Type: Grant
    Filed: October 14, 1980
    Date of Patent: December 1, 1981
    Assignee: Envirotech Corporation
    Inventors: H. David Stensel, Peter Maier, Mark G. Biesinger, David R. Refling, Ronald P. Klepper, John V. Maxham
  • Patent number: 4302328
    Abstract: A process is provided for treating spent geothermal brine to remove silica. The process includes introducing the brine into the reaction zone of a reactor-clarifier and allowing the brine to flow therefrom into the clarification zone of the reactor-clarifier. In the clarification zone, particles settle from the brine and are urged to the center of the tank beneath the reaction zone, and the settled particles are drawn upwardly into the reaction zone by an impeller. The particles mix with the brine in the reaction zone to form a substantially uniform distribution therein to provide nuclei for silica precipitation from the brine. A stream of sludge is removed from the bottom of the reactor-clarifier and disposed of.
    Type: Grant
    Filed: April 27, 1979
    Date of Patent: November 24, 1981
    Assignee: Envirotech Corporation
    Inventor: Robert H. Van Note
  • Patent number: 4302422
    Abstract: A system and process for determining the concentration of nonmethane organic chemicals in a gaseous sample includes a separation system to receive the gaseous sample. In the separation system nonmethane organic chemicals including ethylene and ethane are reversibly retained on a packing material while methane and inert gases pass through the separation system and are vented. Thereafter a carrier gas is directed through the separation system, the nonmethane organic chemicals are released into the carrier gas, and the carrier gas containing the organic chemicals is conveyed to an analyzer for analysis of the organic chemicals.
    Type: Grant
    Filed: March 31, 1980
    Date of Patent: November 24, 1981
    Assignee: Envirotech Corporation
    Inventor: Yoshihiro Takahashi
  • Patent number: 4299114
    Abstract: An ultrasonic system for sensing a liquid-fluid interface comprises a support structure (10) to which a transmitting crystal (21) and a receiving crystal (22) are bonded in such a way that the crystals (21 and 22) are positioned opposite each other across a gap (30). Each of the crystals (21 and 22) has a relatively high resonant frequency and a relatively low resonant frequency. An amplifier means (40) and a bandpass filter means (50) are connected to the crystals (21 and 22) to form a feedback loop. In normal operation, the transmitting crystal (21) is excited to resonate at its high resonant frequency in order to cause transmission of an ultrasonic signal across the gap (30) without causing appreciable ultrasonic transmission through the support structure (10) to the receiving crystal (22).
    Type: Grant
    Filed: June 10, 1980
    Date of Patent: November 10, 1981
    Assignee: Envirotech Corporation
    Inventors: David Silvermetz, George L. Adams
  • Patent number: 4294591
    Abstract: A mounting assembly (12) for suspending an electrically conductive support frame for high-voltage electrodes (10) in an electrostatic precipitator comprises an electrical insulator (20) secured to a roof portion (13) of the precipitator and a fastening means for securing the support frame to the insulator (20). The insulator (20) has a bore therethrough, and is positioned circumjacent an aperture in the roof portion (13). The fastening means includes a rod (23), the lower end of which is attached to a horizontal member (11) of the support frame and the upper end of which extends through the bore of the insulator (20). The upper end of the rod (23) is secured to an annular member (25), which bears against a top portion of the insulator (20) to support the weight of the support frame and of the high-voltage electrodes (10) attached thereto.
    Type: Grant
    Filed: May 12, 1980
    Date of Patent: October 13, 1981
    Assignee: Envirotech Corporation
    Inventor: Melvin R. Kahl
  • Patent number: 4293417
    Abstract: An improved filter press for separating solids from liquid is provided. The press includes a plurality of filter plates which are suspended from overhead I-beams such that the plates may be removed either from the top of the press or from the sides of the press as desired. The filter plates are suspended from the I-beams by rollers which alternate in position for adjacent filter plates between engagement with the outside flanges and engagement with the inside flanges of the beams and, thus, allow larger rollers to be utilized. The filter press includes a press head for moving the individual filter plates into abutting relationship which is pivotally suspended from the I-beams such that the press head can assume the alignment of the filter plates when the press is closed. The press further includes a pair of vertically-arranged, independently-operable hydraulic closing rams for applying different closing pressures at the top and bottom of the filter plates to compensate for variations in plate stacking.
    Type: Grant
    Filed: April 28, 1980
    Date of Patent: October 6, 1981
    Assignee: Envirotech Corporation
    Inventors: Murray M. Guttman, William L. Fismer
  • Patent number: 4293411
    Abstract: Apparatus is disclosed for steam drying a cake of filtered solids formed on a disc filter element of a rotary disc vacuum filter where the disc filter element is mounted on a rotating means for rotation in a container, the lower portion of which includes a slurry tank and the upper portion of which includes a steam hood. The steam hood encloses a portion of the disc filter element in a steam chamber and includes a pair of sidewalls and a spine wall which joins the pair of sidewalls. A linear seal means is mounted to the pair of sidewalls of the hood to define a steam-retaining exit for the steam chamber through which the disc filter element rotatably moves, and includes two elongated flexible flaps which extend in a straight line from the spine wall into the slurry tank.
    Type: Grant
    Filed: January 24, 1980
    Date of Patent: October 6, 1981
    Assignee: Envirotech Corporation
    Inventor: Steven S. Davis
  • Patent number: 4290865
    Abstract: A system and process are provided for recovering copper from a contaminated copper-bearing source such as copper smelter flue dust. The copper-bearing source is leached in an acidic solution to produce a liquor containing dissolved copper and dissolved contaminants. Simple copper sulfides are precipitated from the liquor by reacting the liquor with chalcopyrite and sulfur dioxide. Copper is recovered from the precipitated sulfides.A novel process is provided for precipitating simple copper sulfides from a solution containing both dissolved copper and dissolved contaminants. The solution is combined with precipitation product such that substantially all ferric iron contained in the solution is reduced to ferrous iron. The ferric-free solution is reacted with chalcopyrite solids and sulfur dioxide to precipitate the dissolved copper as simple copper sulfides.
    Type: Grant
    Filed: January 23, 1980
    Date of Patent: September 22, 1981
    Assignee: Envirotech Corporation
    Inventors: Frank A. Baczek, Bruce C. Wojcik, Alexander A. Jueschke, Daniel M. Lewis, Jack C. Otto, Lawrence L. Tuttle
  • Patent number: 4290787
    Abstract: A high-voltage electrostatic precipitator is powered by a transformer supported below the high-voltage electrodes. A lead-in conductor extends from the transformer to the electrodes through a screen-covered aperture in the precipitator housing. Purging gas is directed through the aperture to prevent accumulation of particulates on the lead-in conductor.
    Type: Grant
    Filed: May 12, 1980
    Date of Patent: September 22, 1981
    Assignee: Envirotech Corporation
    Inventor: Melvin R. Kahl
  • Patent number: 4288229
    Abstract: Total organic carbon can be determined for each one of a plurality of discrete aqueous samples containing halide ion by means of an apparatus comprising a reactor (13), and a pump (12) and flowline (11) for introducing a continuous flow into the reactor (13) of a solution that contains an oxidizing agent and mercuric monohalide ion without forming an insoluble precipitate. The solution to be introduced into the reactor (13) is prepared by mixing the oxidizing agent with a solution containing mercuric monohalide ion; and the solution containing mercuric monohalide ion is formed by adding a quantity of mercuric halide and a quantity of mercuric nitrate to an aqueous solution containing nitric acid, where the molar concentration of the mercuric halide is at least equal to the molar concentration of the mercuric nitrate.
    Type: Grant
    Filed: April 21, 1980
    Date of Patent: September 8, 1981
    Assignee: Envirotech Corporation
    Inventor: Danny M. Mar
  • Patent number: 4284417
    Abstract: In a system for controlling electric power supplied to corona-generating electrodes in an electrostatic precipitator (10), an opacity-sensitive transducer (20) produces an output signal proportional to the opacity of the flue gas exiting from the precipitator (10). The signal from the transducer (20) is compared in comparators (304 and 305) with pre-set upper and lower limits defining a permissible opacity range for the flue gas. When the signal from the transducer (20) exceeds the pre-set upper limit or falls below the pre-set lower limit, automatic voltage controllers (40) are activated to control the power supplied to the corona-generating electrodes in order to restore the flue gas opacity to the permissible opacity range.
    Type: Grant
    Filed: March 17, 1980
    Date of Patent: August 18, 1981
    Assignee: Envirotech Corporation
    Inventors: Robert O. Reese, Karl R. Wieber, James A. Sholly
  • Patent number: 4282082
    Abstract: A slurry electrowinning apparatus includes a tank (10) in which are mounted alternating, spaced-apart anode (18) and cathode (20) electrodes. An inlet opening (60) is formed in a side of the tank (10) for introducing a copper-bearing electrolyte to the tank (10). An overflow opening (76) is also formed in a side of the tank (10) such that a solution level (62) is maintained in the tank (10) which is above the inlet opening (60). Baffles (64) are mounted within the tank (10) for evenly distributing the slurry within the tank (10) between the anodes (18) and cathodes (20). Both the anodes (18) and the cathodes (20) are supported within the tank (10) by electrode guides (22) such that a high pressure contact between the electrodes (18, 20) and the main electrical bussing (78) is provided.
    Type: Grant
    Filed: January 29, 1980
    Date of Patent: August 4, 1981
    Assignee: Envirotech Corporation
    Inventors: Robert D. Cook, Robert C. Emmett, Jr., Bruce C. Wojcik, Frank A. Baczek
  • Patent number: D262973
    Type: Grant
    Filed: September 1, 1978
    Date of Patent: February 9, 1982
    Assignee: Envirotech Corporation
    Inventors: John Griffin, T. Daryl Hatch