Patents Assigned to Envirotech Corporation
  • Patent number: 4624783
    Abstract: Apparatus for backwashing the filter media of a liquid filtering machine while at the same time enabling the machine to filter liquid. The machine is of the type having a tank and a continuous bed of granular filter media in the tank through which liquid having suspended solids therein for removing the solids. The apparatus comprises a partitioning chamber and a carriage for selectively supporting and conveying the chamber above the media bed, with the chamber being insertable into the bed to isolate a portion thereof from the remainder of the bed. The apparatus further comprises a mechanism to selectively allow insertion of the chamber into the bed and to remove it, and a pump to draw liquid through the isolated portion of the bed to backwash it, while filtration may proceed in the remainder of the bed. Apparatus for removing the media from the chamber and replacing it with new, cleaned or regenerated media is also disclosed.
    Type: Grant
    Filed: January 22, 1985
    Date of Patent: November 25, 1986
    Assignee: Envirotech Corporation
    Inventors: Brent C. Black, Bruce D. Bradley, Ralph B. Haymore
  • Patent number: 4624787
    Abstract: A lifting mechanism for a raking structure in a solids-liquid separation tank comprising a fixed column adapted to extend vertically within the tank, a movable column being adapted to support a raking structure for the tank, and a lift device for raising and lowering said movable column telescopically with respect to said fixed column. The lift device includes an elongate flexible tension member; a first series of load points on the fixed column at spaced intervals on the fixed column; and a second series of lift points on the movable column below said first series of points and at spaced intervals on the movable column, the tension member being alternately threaded between load and lift points of said first and second series of points, with the tension member thus being led over one of said load points, down and below one of said lift points and back up and over the next load point.
    Type: Grant
    Filed: May 6, 1985
    Date of Patent: November 25, 1986
    Assignee: Envirotech Corporation
    Inventors: Ralph B. Haymore, Heinz W. Winter
  • Patent number: 4588559
    Abstract: A lime slaking system for hydration of lime and removal of unwanted grit, particularly for formation of reactive slaked lime to be used in SO.sub.2 scrubbing of effluent gases, comprising a series of slaking vessels (10, 12) for reacting CaO and water while agitating the reactants, a dilution mix tank (14) receiving a viscous slaked lime slurry from the vessels, diluent for the dilution tank comprising an upstream classifier overflow stream (16), a cyclone (19) receiving pumped diluted slurry from tank (14), the overflow (21) of the cyclone providing usable slaked lime product and the underflow (22) exiting to the upstream classifier (24) where grit materials are separated and removed. Dilution for effective classification is provided by spent scrubbing process water containing appreciable sulfate ions.
    Type: Grant
    Filed: September 27, 1984
    Date of Patent: May 13, 1986
    Assignee: Envirotech Corporation
    Inventor: Robert C. Emmett
  • Patent number: 4588037
    Abstract: This turret has a head 6 enabling, after the drilling of a hole 15, the injection of a resin cartridge without modifying the position of the turret 1. A movable member 8, displaced by a jack 14, has a first passage 11 traversed by the drilling rod 4, and a second passage 12 connected to the hose 13 for the injection of resin cartridges. After the drilling of the hole 15 and the retraction of the drilling apparatus 2, the movable member 8 is displaced such that the drilling rod 4 is laterally retracted by bending. The second passage 12 is simultaneously brought in line with the axis of the hole 15 so as to enable the injection of one or more resin cartridges.
    Type: Grant
    Filed: December 11, 1984
    Date of Patent: May 13, 1986
    Assignee: Envirotech Corporation
    Inventor: Michel Combet
  • Patent number: 4575256
    Abstract: A draft tube mixer is disclosed particularly adapted for use with digestion processes and apparatus wherein a vertical shaft (13) is driven by motor (15) through a suitable drive (14) to rotate a ragless propeller (12). The propeller (12) has a series of three lobes or blades (40-42) which are concentrically arranged at 120.degree. apart positions so that the minimum diameter of the blades are at the ends of a hub (43) from which the blades integrally extend. The blades extend over the length of the hub over about a 360.degree. of rotary motion. The blades (40-42) are symmetrical from their ends to the mid points on the vanes from either direction top or bottom so that the propeller is reversible without loss of efficiency.
    Type: Grant
    Filed: September 19, 1983
    Date of Patent: March 11, 1986
    Assignee: Envirotech Corporation
    Inventors: Jack R. Armitage, Ralph B. Haymore
  • Patent number: 4561978
    Abstract: A dual-belt method and apparatus for dewatering a water laden cake of material through the use of multiple primary dewatering rolls is disclosed. A pair of porous belts containing filter cake disposed between the belts are wrapped around a first and second primary roll so that the belts circumscribe more than a 180.degree. arc of each roll. The pressure applied to the belts, that is, to the filter cake, is greater on the second roll than on the first roll.
    Type: Grant
    Filed: October 9, 1984
    Date of Patent: December 31, 1985
    Assignee: Envirotech Corporation
    Inventor: Kenneth F. Janecek
  • Patent number: 4551285
    Abstract: A froth flotation machine (40) having a rotary air-supply shaft (42) vertically disposed in a vessel (41) includes an impeller (50) comprising a series of interconnected blades (52,53). Extending radially and fixedly depending from a flat impeller plate (52) is a pumping blade extending over one-half the distance from the plate outer periphery to the shaft. Blade (53) is an air-inducing vane of lesser radial length which aids in inducing air from shaft (42) to pumping blades (52). The vane has a height less than 50% of the height of the pumping blade. The pumping blade has an L/H ratio of from 0.8 to 1.4 where L is its radial length and H is its vertical height. Slurry is pumped by the blades (52) from bottom of the vessel through a central aperture in a surrounding fixed stator base (56) having stator bars (55) extending upwardly and forming parallel-sided passageways (63,64) for pumped fluid.
    Type: Grant
    Filed: February 9, 1984
    Date of Patent: November 5, 1985
    Assignee: Envirotech Corporation
    Inventor: Michael A. Jackson
  • Patent number: 4541210
    Abstract: A cover and erection method for a tank, sedimentation device or building cover constructed over or within a generally continuous upstanding circular side wall (30), made up of a series of concentric spaced thrust rings (11, 12, 21) having multiple short curved radial beams (14, 19) bridging the annuli between the rings and cover plates (17, 21) extending across the spaces between adjacent ones of the beams between each of the spaced rings. Erection may be from the wall inwardly or from the center to the wall. In either event an intermediate thrust ring is temporarily supported at an elevation above and within the side wall and the beams set across the rings in relatively short radial spans prior to welding of beams and plates to the respective rings. By this technique, small lightweight beams can be utilized for building large-diameter covers or domes with each rise span being of relatively small length.
    Type: Grant
    Filed: June 23, 1983
    Date of Patent: September 17, 1985
    Assignee: Envirotech Corporation
    Inventor: Lynn W. Cook
  • Patent number: 4515694
    Abstract: A lifting mechanism for a rake arm and rake structure employed to move sediments settling out from a solids-liquid slurry in a sedimentation tank, includes a fixed center column (27) in the tank and a concentric movable column (28) in telescoping relation to the fixed column. A first series of sheave assemblies (40) are attached to or fixed with respect to the fixed column and a second series of sheave assemblies (51-55) attached to the movable column at a vertically displaced distance from the first series. The respective sheave assemblies may extend in part in an annulus (34) between the fixed and movable columns and are positioned around the peripheries of the respective columns. A continuous cable (45) extends alternately between individual sheaves in each series and the ends of the cable are attached to a vertical take-up drum (38).
    Type: Grant
    Filed: May 2, 1983
    Date of Patent: May 7, 1985
    Assignee: Envirotech Corporation
    Inventors: Ralph B. Haymore, Heinz W. Winter
  • Patent number: 4482528
    Abstract: A lime slaking system for hydration of lime and removal of unwanted grit, particularly for formation of reactive slaked lime to be used in SO.sub.2 scrubbing of effluent gases, comprising a series of slaking vessels (10,12) for reacting CaO and water while agitating the reactants, a dilution mix tank (14) receiving a viscous slaked lime slurry from the vessels, diluent for the dilution tank comprising an upstream classifier overflow stream (16), a cyclone (19) receiving pumped diluted slurry from tank (14), the overflow (21) of the cyclone providing usable slaked lime product and the underflow (22) exiting to the upstream classifier 24 where grit materials are separated and removed. Dilution for effective classification is provided by spent scrubbing process water containing appreciable sulfate ions.
    Type: Grant
    Filed: January 10, 1983
    Date of Patent: November 13, 1984
    Assignee: Envirotech Corporation
    Inventor: Robert C. Emmett
  • Patent number: 4475453
    Abstract: A method and apparatuses for expressing the liquid phase from a wet mixture such as a clay-like mixture includes a primary roll (12, 104) with a plurality of smaller pressure rolls (13, 112-118) biased against its surface at circumferentially spaced intervals and at increasing pressures. The primary roll and at least the upstream one (112) of the pressure rolls have a thick outer covering of a substantially deformable elastomeric material. A pair of opposed filter belts (22, 23 or 142, 144) are trained about the primary roll and means are provided to feed the wet mixture between the belts to carry the mixture successively through the nips between the primary roll and the pressure rolls. The mixture is initially subjected in the first nip to a relatively gradual rate of increase in pressure and in subsequent nips is subjected to progressively steeper rates of increase in pressure adapted to the different flow behavior of the mixture caused by the increasing solids content of the mixture.
    Type: Grant
    Filed: January 26, 1982
    Date of Patent: October 9, 1984
    Assignee: Envirotech Corporation
    Inventor: Steven Davis
  • Patent number: 4465293
    Abstract: An oscillation lock for an articulated mining vehicle having a front frame and rear frame with pivot means therebetween which prevents oscillation and possible tipping of the vehicle when hauling heavy front-mounted loads. The device includes a mounting plate attached to one of said frames cross-wise of the pivot link between the frames and a lock plate assembly including a pair of depending stop blocks which blocks and plates in assembled position straddle the pivot link and restrict oscillatory movement between the frames.
    Type: Grant
    Filed: October 28, 1982
    Date of Patent: August 14, 1984
    Assignee: Envirotech Corporation
    Inventors: William S. McNab, Jerry A. Phifer
  • Patent number: 4454042
    Abstract: A rotatable drum solids-liquids separation device having bailer scoop means forming a fluid-holding trough attached to and rotatable with the drum which is operable to pick-up fluid in an internal drum sump and during rotation to lift and transport the fluid to an outlet position higher in elevation than the sump level, normally at the centerline of the drum.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: June 12, 1984
    Assignee: Envirotech Corporation
    Inventor: Samuel H. Dorcheus
  • Patent number: 4450077
    Abstract: An improved filtering machine of the down-flow type is disclosed wherein a particular section of a granular media filtration bed is isolated for backwashing while allowing filtration to proceed in the remainder of the bed. The filter machine includes a liquid-holding tank containing a bed of granular media, structure permitting passage of filtrate through the bed from below, a flume for distributing influent liquid containing suspended solids across the bed for downward percolation therethrough, and a partitioning chamber mounted on a carriage mechanism which selectively conveys the partitioning chamber across the surface of the bed. The partitioning chamber is reciprocatably insertable into the bed to isolate selected sections from the remainder of the bed. A pump is in communication with the partitioning chamber to draw liquid upward through the bed within the isolated section.
    Type: Grant
    Filed: August 6, 1982
    Date of Patent: May 22, 1984
    Assignee: Envirotech Corporation
    Inventors: Brent C. Black, Bruce D. Bradley, Ralph B. Haymore
  • Patent number: 4447072
    Abstract: A suspension for a rigid front axle assembly (28) of an articulated mining truck (10) includes a bolster plate (30) upon which the axle assembly is fixedly cradled, a spherical or swivel bearing assembly (36) connecting the front end of the bolster plate to the chassis of the vehicle, and a hollow unitary elastomeric block (70) that is mounted to resiliently couple the rear end of the bolster plate to the chassis. The elastomeric block is preferably elongate and longitudinally oriented, and the block has a cavity that extends longitudinally through its center that is aligned with a longitudinal axis (A-A) through the spherical bearing. The elongate walls thus provided at the sides of the elastomeric block are sufficiently flexible to bulge outwardly when the axle assembly oscillates about the longitudinal axis A-A.
    Type: Grant
    Filed: December 14, 1981
    Date of Patent: May 8, 1984
    Assignee: Envirotech Corporation
    Inventors: Kirk D. Bradley, Robert R. Koski, James W. Clark
  • Patent number: 4439938
    Abstract: A coupling system includes a connecting assembly 4 having two upwardly facing critically angled U-shaped lifting forks mounted at the upper ends of its sides. A bucket 2 has two transversely spaced locating members 6 and 8 defining a central profiled portion 10. Two co-linear transverse pins 12 are mounted at the top of the portion 10, and a central recess 18 is formed in the profiled portion 10. An end member 22 having an aperture 24 therein is located at the base of the recess 18. A latch bar 34 and an operating cylinder 36 are mounted on the assembly 4, and are dimensioned to fit in the recess 18.In operation, the assembly 4 is tilted forwardly and advanced until the lifting pins 12 enter the forks 32. The assembly 4 is then tilted backwards and edged forwardly until the cylinder 36 and the latch bar 34 enter the recess 18. The cylinder 36 is then operated to advance the latch bar 34 into the aperture 24 to couple together the bucket 2 and the assembly 4.
    Type: Grant
    Filed: November 4, 1983
    Date of Patent: April 3, 1984
    Assignee: Envirotech Corporation
    Inventor: David Grant
  • Patent number: 4424130
    Abstract: An apparatus for driving and lifting the rake assembly in a sedimentation basin. An annular hub is mounted on the main gear member, such hub having slot means through which vertical edges of a vertically-extending rectangular torque-plate are slidably affixed. Torque is transmitted from the gear member, through the hub slot means, to the torque plate and to the rake assembly which is attached generally at the bottom of the torque plate. Side loads (horizontal unbalanced rake loads) are transmitted from the vertical edges of the torque plate through the hub slots to the main gear bearing in the drive. Means is also provided attached to the torque-plate to move the torque-plate upwardly through the slot means so as to raise and lower the rake assembly.
    Type: Grant
    Filed: September 2, 1982
    Date of Patent: January 3, 1984
    Assignee: Envirotech Corporation
    Inventor: Donald L. King
  • Patent number: 4405453
    Abstract: A process for cleaning undeslimed coal includes the steps of determining the scalar value of cross-correlation function of the measured values of the percent magnetics and the bulk specific gravity of a heavy media and coal slurry being fed to a cyclone, comparing the value to a set-point value determined after start-up when the recirculating suspension in the feed slurry is normally clean, and diverting at least a portion of the heavy media suspension that is separated from the underflow of the cyclone from being mixed with the feed coal slurry, to thereby correspondingly reduce the slime content of the feed slurry, and concurrently increasing the flow of cleaner heavy media suspension to the feed coal slurry until the cross-correlation function is brought up to the set-point value. Also disclosed is an embodiment of the process for cleaning coal, wherein the overflow from the cyclone is screened and screened solution is split between a first recycle loop for cleaning the suspension and the heavy media sump.
    Type: Grant
    Filed: February 23, 1982
    Date of Patent: September 20, 1983
    Assignee: Envirotech Corporation
    Inventor: Charles H. Wells
  • Patent number: 4391705
    Abstract: A digestor includes a tank and an inverted dish-shaped cover, the lower end of which extends into sludge contained within the tank. The cover is ballasted by a number of ballast members which resemble tubs and which are integrally formed of concrete. Each ballast member is mounted with its cavity facing upwardly so that the ballast cavities automatically fill with sludge upon start-up of the digestor. When partially surfaced above the sludge, the predetermined total weight of sludge in the ballast members causes a substantial increase in the pressure exerted by the cover on the contained gas than would be exerted by the cover and unfilled ballast members.
    Type: Grant
    Filed: May 29, 1981
    Date of Patent: July 5, 1983
    Assignee: Envirotech Corporation
    Inventors: Lynn W. Cook, David P. Brown
  • Patent number: 4378437
    Abstract: An improved anaerobic digester 10 includes a cylindrical concrete sidewall 16 having a plurality of guide channel assemblies 40 bolted thereto at uniformly spaced locations along its circumference. The digester further includes a cover 18 adapted to be buoyed upwardly above the surface of the liquid by the digester gas. The digester cover is guided by roller assemblies 70 that cooperate with the guide channel assemblies 40. When gas is not present within the digester, the cover is supported by the cooperation of a plurality of stop tubes 76 and 78 that project radially outwardly of the cover from a thrust ring 24 incorporated at its periphery and a plurality of stop members 60 and 62 that are affixed to the guide channel assemblies at readily accessible locations close to the top of the tank.
    Type: Grant
    Filed: October 28, 1981
    Date of Patent: March 29, 1983
    Assignee: Envirotech Corporation
    Inventor: Lynn W. Cook