Patents Represented by Attorney Thomas S. MacDonald
  • Patent number: 4022697
    Abstract: An apparatus for separating solids from liquids by sedimentation includes a covered tank in which a sediment-engaging raking structure is journaled for rotation about a central support pier. The raking structure is driven by a unit which travels about the periphery of the tank outside the enclosure. A gas-tight seal is effected between the tank, the cover and the drive unit by the combination of an annular liquid-holding launder which is fixedly supported to surround the interior of the tank, a rigid U-shaped member which connects the drive unit to the raking structure with its lower portion submerged in the liquid held in the launder, and a continuous baffle-like wall extending from the tank cover downwardly into the space bounded by the submerged portion of the U-shaped member.
    Type: Grant
    Filed: March 6, 1975
    Date of Patent: May 10, 1977
    Assignee: Envirotech Corporation
    Inventor: Peter Jerome Pankuch
  • Patent number: 4019963
    Abstract: In a coke quench car having a hood and a draft inducing mechanism or exhaust device, a closure plate apparatus is associated with the coke oven push guide and is positionable with respect to the open side of the quench car so as to substantially close the open side of the car. The gap between the guide and the edges of the open side of the quench car are draft openings through which air is drawn by the draft inducing mechanism to withdraw gaseous and particulate emissions from the coke as it is pushed into the car. The gap confines or concentrates the inflow of air so as to prevent discharge of gaseous or particulate emissions around the hood of the car.
    Type: Grant
    Filed: October 6, 1975
    Date of Patent: April 26, 1977
    Assignee: Envirotech Corporation
    Inventor: John F. Hanley, Jr.
  • Patent number: 4013023
    Abstract: The following disclosure teaches ways and means for incinerating organic wastes in a multiple hearth furnace equipped with an afterburner. In the furnace, the wastes are pyrolyzed in an oxygen deficient atmosphere which is regulated to only partially complete the oxidation of the organic substances which are pyrolyzed from the wastes. In the afterburner, air is introduced to complete the oxidation of the partially oxidized substances carried by gases and vapors from the furnace. The air supply to the afterburner is controlled so that, at temperatures above a predetermined temperature, the quantity of air introduced is increased with increasing temperatures and is decreased with decreasing temperatures. In other words, the pyrolyzing furnace is caused to operate with a deficiency of air over its operating range, while the afterburner is caused to operate with excess air and the amount of excess air supplied is used to control the operating temperature by quenching.
    Type: Grant
    Filed: December 29, 1975
    Date of Patent: March 22, 1977
    Assignee: Envirotech Corporation
    Inventors: Luis A. Lombana, Jose G. Campos
  • Patent number: 4012316
    Abstract: A device for hydraulically classifying solid fragments includes two side-by-side liquid-holding compartments between which liquid is continuously circulated; the liquid flows through a flow tube connecting the lower region of the first compartment with the second compartment, then flows upwardly through a throat zone in the first compartment and then over a weir back to the second compartment. The flow tube has a convergent mouth in the second compartment and a divergent outlet in the first compartment. A pump is arranged to withdraw a fraction of the circulating liquid from the second compartment and to inject that liquid into an eductor arranged at the mouth of the flow tube in the second compartment. Solids classification is accomplished at the throat zone: heavier solids sink through the throat zone, and lighter solids are carried upward in the rising current over the weir and onto a drainage screen.
    Type: Grant
    Filed: April 18, 1975
    Date of Patent: March 15, 1977
    Assignee: Envirotech Corporation
    Inventors: Sven E. Ostlund, Robert S. Bailey, Sr.
  • Patent number: 4012669
    Abstract: A device for detecting a persisting electrical overload in an electrical system includes means for monitoring an electrical parameter in the electrical system and for generating an electrical signal whose magnitude represents the instantaneous absolute value of the parameter, reference means which generates an output signal of predetermined value and which develops, in cooperation with the monitoring means, an electrical signal whose magnitude represents the amount by which the magnitude of the absolute value signal exceeds the predetermined value, integrator means to integrate the aforementioned electrical signal and to generate an output whose magnitude includes a component representative of the product of the electrical signal and a time-increasing value that represents the duration that an overload has persisted; and comparator means to continuously compare the magnitude of the integrator output signal with a second preselected value and which generates an indicative output whenever the integrator output
    Type: Grant
    Filed: August 29, 1975
    Date of Patent: March 15, 1977
    Assignee: Envirotech Corporation
    Inventors: Peter C. Gelfand, Clifford A. Mason
  • Patent number: 4008158
    Abstract: A dewatering machine comprises an integral and cooperative combination of a vacuum filter of the rotary drum type and an expression device of the diaphragm type. An intermittently-indexed endless filter medium belt carries a sheet of filter cake to the expression device after the cake is formed on the vacuum filter. The belt indexing action is coordinated with pressurization of the expression device so that the filter drum is indexed only when the diaphragm is relaxed and the pressurization is effected only at such times as the drum is not being indexed.
    Type: Grant
    Filed: June 19, 1975
    Date of Patent: February 15, 1977
    Assignee: Envirotech Corporation
    Inventor: Steven S. Davis
  • Patent number: 4008057
    Abstract: Electrically-activated shaking devices are arranged in modules to shake the electrodes of an electrostatic precipitator, each module corresponding to a different section of the precipitator. An operating system for the shaking devices includes a main distributor circuit that sends electrical signals to individual control circuits at each of the modules in sequence and at a relatively fast rate. Each control circuit has an adjustable timer that independently generates pulses at a relatively slow rate and a synchronizing circuit that generates an output signal only if it receives a signal from the timer followed by a signal from the main distributor. Each control circuit further includes a secondary distributor circuit that operates in response to the synchronizing circuit to activate the shaking devices in the associated module sequentially. An inhibit device operated by the synchronizing circuit prevents more than a single shaker from being activated at a time.
    Type: Grant
    Filed: November 25, 1974
    Date of Patent: February 15, 1977
    Assignee: Envirotech Corporation
    Inventors: Peter C. Gelfand, Richard A. Carpenter, Jerry F. Shoup
  • Patent number: 3996133
    Abstract: A process for reclaiming calcium values from the solid residual of incineration or calcination of calcium-bearing sewage and water sludges includes the following steps: classifying the residuals on the basis of their size and density to form two classified streams, the first of which contains relatively larger sized solid particles and has a relatively decreased concentration of calcium and the second of which contains relatively increased concentration of calcium for reuse; then mixing the particles in the first stream with water to form an aqueous solution containing calcium hydroxide; then clarifying the aqueous solution in a settling zone to form a sediment relatively rich in the insoluble inert solids and a decanted stream which is relatively rich in calcium values.
    Type: Grant
    Filed: April 11, 1975
    Date of Patent: December 7, 1976
    Assignee: Envirotech Corporation
    Inventor: Orris E. Albertson
  • Patent number: 3993563
    Abstract: An apparatus for ingesting and mixing gas into a liquid body includes a tank, a rotatable impeller fixed to a vertical drive shaft, and a vertically-extending conduit which surrounds the drive shaft and which extends to a location in the liquid above the impeller to serve as a channel of communication between a source of gas and the impeller. In the conduit, a vortex-turning baffle having an enlarged gas-flow aperture formed centrally therethrough is fixedly mounted above the impeller so that when a rotor-induced liquid vortex rises along the wall of the conduit, the vortex is turned downwardly by the baffle to aid in the ingestion of gas into the liquid.
    Type: Grant
    Filed: April 28, 1975
    Date of Patent: November 23, 1976
    Assignee: Envirotech Corporation
    Inventor: Vernon R. Degner
  • Patent number: 3992298
    Abstract: A dewatering machine comprising an integral and cooperative combination of a vacuum filter of the rotary drum type and an expression device of the type wherein a diaphragm is pressed against a drainage deck. An intermittently-indexed first endless filter medium belt carries filter cake to the expression device after the cake is formed on the vacuum filter. A second endless filter belt is trained to run beneath the diaphragm of the expression device parallel to the drainage deck and above the first filter belt so that the filter cake is sandwiched between the two filter belts. The belt indexing action is coordinated with pressurization of the expression device so that the filter drum is indexed only when the diaphragm is relaxed and the pressurization is effected only at such times as the drum is not being indexed. The second filter belt prevents the pressed material from adhering to the diaphragm of the expression device.
    Type: Grant
    Filed: March 22, 1976
    Date of Patent: November 16, 1976
    Assignee: Envirotech Corporation
    Inventor: Steven S. Davis
  • Patent number: 3991689
    Abstract: Apparatus for incinerating grease-laden aqueous mixtures includes a burner assembly or having a swirl chamber whereinto the liquid is tangentially fed and swirled. From a nozzle connected to the chamber, a minor fraction of the feed mixture is emitted as a rotating, atomized spray for subsequent ignition. A major fraction of the feed is continuously recycled thereby maintaining a high liquid flow rate through the burner assembly. A system is described for conditioning feed mixtures, and particularly sewage water skimmings of the type derived from a primary sewage treatment operation prior to delivering them to the burner assembly; the system includes means for grinding, heating and settling the materials before incinerating them.
    Type: Grant
    Filed: April 11, 1975
    Date of Patent: November 16, 1976
    Assignee: Envirotech Corporation
    Inventor: Ulf F. Rinecker
  • Patent number: 3989464
    Abstract: Sulfur dioxide is scrubbed from stack gases in an absorption device by a sodium-based aqueous scrubbing solution, a portion of which is subsequently and continuously regenerated outside the absorption apparatus by a causticizing reaction with slaked lime. The causticized solution is routed through a settling device wherefrom a portion of the aqueous sediment is returned to the causticizing zone to provide seed crystals which encourage the formation of larger sized solid particles; also, a portion of the aqueous sediment from the settling device is continuously mechanically dewatered and then removed from the system. The liquid effluent solution from the settling device is passed to a solids-contacting and reaction device for mixing with sodium carbonate in order to reduce the calcium ion concentration and the solids content of the solution. The underflow of the solids-contacting device is conveyed back to the causticizing zone and the clarified overflow, i.e.
    Type: Grant
    Filed: February 24, 1975
    Date of Patent: November 2, 1976
    Assignee: Envirotech Corporation
    Inventors: Donald A. Dahlstrom, Conrad F. Cornell
  • Patent number: 3972682
    Abstract: A furnace assembly for use in a chemical analysis system utilizing high-temperature pyrolytic techniques includes a refractory tube which defines a heated chamber wherein samples are pyrolyzed, inlet and outlet cap members mounted on opposite ends of the refractory tube, a cylindrical heating assembly which spacedly surrounds the refractory tube, and a frame which fixedly supports both the refractory tube and the heating assembly in a vertical orientation. The frame includes a stationary mounting plate and at least two rod-like members which fixedly extend in parallel downward from the stationary plate on opposite sides of the heating assembly. The heating assembly is fixed to the rods and a springy plate member is fixedly connected between the rods to provide a support upon which the outlet cap member rests and to press upwardly against the refractory tube when the same elongates during heating so that the upper and lower cap members are forceably sealed against the respective ends of the refractory tube.
    Type: Grant
    Filed: October 6, 1975
    Date of Patent: August 3, 1976
    Assignee: Envirotech Corporation
    Inventors: Thomas M. Stephens, Yoshihiro Takahashi
  • Patent number: 3969247
    Abstract: An improved process for dewatering sodium bicarbonate solids and similar substances formed as a cake on a rotary drum vacuum filter that is disposed for rotation in partial submergence in a slurry containing the suspended solids. The process includes the steps of pressing the filter cake against the surface of the filter drum by means of a pressure-applying roll which is driven to rotate so that its surface velocity exceeds the velocity of the drum surface by 25 to 75% and, thereafter, drawing steam through the filter cake while it is still on the surface of the filter drum.
    Type: Grant
    Filed: June 20, 1975
    Date of Patent: July 13, 1976
    Assignee: Envirotech Corporation
    Inventors: Robert C. Emmett, Jr., Benjamin K. Pocock
  • Patent number: 3958945
    Abstract: A device for sparging carbon dioxide from an acidified aqueous stream for use in a system for quantitatively determining the organic carbon content of the stream has a body with vertically extending cavities formed therethrough and passageways which connect the cavities in series so that the aqueous stream travels the length of a cavity before passing into the next. Dispersion tubes are mounted in the cavities for dispersing fine bubbles of sparging gas into the aqueous stream. The gas and carbon dioxide which has evolved from the aqueous stream is collected and discharged through the cavities.
    Type: Grant
    Filed: October 4, 1974
    Date of Patent: May 25, 1976
    Assignee: Envirotech Corporation
    Inventor: Yoshihiro Takahashi
  • Patent number: 3955947
    Abstract: Impacting devices are provided to strike the sway frame which supports the filtering bags in a bag house. The impacting devices each include a stationarily-mounted bracket, an externally-threaded sleeve that is adjustably received in the bracket, a bolt-like striker member slidable in the sleeve and a coil spring which biases the striker member to an extended position relative to the sleeve.
    Type: Grant
    Filed: November 13, 1974
    Date of Patent: May 11, 1976
    Assignee: Envirotech Corporation
    Inventors: Harry E. Hoon, Marion C. Pogoda
  • Patent number: 3955950
    Abstract: A hanger system particularly for cyclone collectors in a fluidized particle process vessel, such as a fluid catalytic cracker regenerator vessel, wherein a vertical supporting member is pinned at one end to a cyclone wall lug and at the other through a slot in a vessel depending lug so that thermal and mechanical stresses within the overall assembly are compensated for by sliding movement of the pin in the slot, which movement is controlled by a stabilizing linkage member attached to the pin at one end and pivotably attached at the other end to the vessel.
    Type: Grant
    Filed: May 19, 1975
    Date of Patent: May 11, 1976
    Assignee: Envirotech Corporation
    Inventor: James Frank Miller, Jr.
  • Patent number: 3948104
    Abstract: A sampling valve includes upper and lower flat-faced body sections that are mounted facing one another for rotation about a generally centrally disposed shaft with a thin seal member interposed between the sections. A reciprocative device selectively rotates the upper body section relative to the lower section through a pre-selected angle about the shaft. A passage is formed from the lower body section to the upper section so that liquid continuously flows through the valve. At one portion of the valve, the passage is in communication with a bore of a sample-taking piston assembly which is arranged on the upper body section. The piston is driven upward to draw a liquid sample from the flowing liquid in the passage and then the upper body section is rotated and the sampling piston is driven downward to eject the sample into a pyrolysis furnace or the like.
    Type: Grant
    Filed: October 4, 1974
    Date of Patent: April 6, 1976
    Assignee: Envirotech Corporation
    Inventor: Thomas M. Stephens
  • Patent number: 3947350
    Abstract: Process for preparing sludge for dewatering in a tertiary line precipitation treating system in which raw sewage has been dosed with calcium hydroxide to remove phosphates. A source of carbon dioxide is introduced into the treating system to convert calcium hydroxide salts and other salts to the more readily dewatered carbonate form, and to convert magnesium hydroxide salts to the bicarbonate form to facilitate removal of magnesium from the system. Carbon dioxide may be introduced in gaseous form, an available source of which is the exhaust gases from sludge incineration following dewatering thereof. Alternatively, sulfuric acid or hydrochloric acid or other suitable chemical reactant may be introduced into the system to neutralize the higher pH of the sludge. Conversion of the sludge to the carbonate form is effected in conjunction with the production of carbon dioxide during the neutralization reaction effected by the chemical reactants introduced into the system.
    Type: Grant
    Filed: July 19, 1974
    Date of Patent: March 30, 1976
    Assignee: Envirotech Corporation
    Inventor: Paul J. Cardinal, Jr.