Patents Assigned to Tennessee Valley Authority
  • Patent number: 4760784
    Abstract: Apparatus useful as a compacting device adapted to be inserted into a barrel or similar container either singularly, or in combination with a plurality of similar devices and generally comprising one or more compacting plates which plates are adapted to fit within such container and disposed therein for movement in a direction generally parallel to the axis of such container. A plurality of resilient locking tabs are secured to the upper surface of such compacting plates each by means of an angle bracket and in a manner so as to extend beyond both the peripheral surface of such compacting plate and the outermost edge of said angle bracket to thereby provide for engagement of said tabs with the inside of such container. When loose material is placed in the container, and a compacting plate is inserted thereinto and pressed downwardly, the material within the container and under said plate will be compacted.
    Type: Grant
    Filed: July 15, 1987
    Date of Patent: August 2, 1988
    Assignee: Tennessee Valley Authority
    Inventor: Richard W. Whiteside
  • Patent number: 4758261
    Abstract: Improved, simple, energy-efficient, and easy-to-operate process for producing granular diammonium phosphate (DAP) fertilizers from anhydrous ammonia, phosphoric acid, sulfuric acid, and water utilizing a rotating drum granulator and a pipe reactor in combination with a specially designed slurry distributor. The pipe reactor operates at pressures of more than 80 pounds per square inch gage and utilizes a special low-impact distributor to uniformly distribute a wide-angle spray of slurry onto the bed of recycled solids in the drum granulator and to provide for a minimum of bed disruption and deformation. This energy-efficient process produces dry, free-flowing granular DAP with little or no fossil-fuel heating requirements for drying and with low recycle ratios which allow for high production rates or increases in production rates when the process is retrofitted into existing plants.
    Type: Grant
    Filed: November 30, 1987
    Date of Patent: July 19, 1988
    Assignee: Tennessee Valley Authority
    Inventors: Byron R. Parker, Barry W. Curtis
  • Patent number: 4757263
    Abstract: The present invention teaches a technique and provides for apparatus eminently useful for the continuous, simultaneous monitoring of the insulation quality of one or more pieces of high voltage ac electrical equipment, while the equipment is in service and connected to its normal high voltage source. The technique or method of the instant invention involves comparing a voltage, developed across a capacitive shunt at the capacitance tap of a transformer or bushing so equipped with a reference voltage taken from a voltage transformer or potential device connected to the same high voltage source.
    Type: Grant
    Filed: May 1, 1987
    Date of Patent: July 12, 1988
    Assignee: Tennessee Valley Authority
    Inventors: Harold B. Cummings, III, Frank A. Deviney
  • Patent number: 4743289
    Abstract: An improved process for more economically and effectively producing crystalline by-product ammonium sulfate (A/S) by granulating crystalline by-product A/S feedstock and recycle material together with an A/S-sulfuric acid-granulation aid-particle hardener solution and ammonia to bind the crystals together. Underlying the gist of the improvement concept is the identification of a low-cost readily available lignosulfonate by-product of the pulp and paper industry which, when used in predetermined and relatively small proportions, has now been discovered to be very satisfactory as a granulation aid-particle hardener for granulating such by-product ammonium sulfate crystals. Use of lignosulfonate instead of alum, as is currently practiced, reduces the manufacturing cost of granulating by-product ammonium sulfate by about as much as one dollar per short ton of product.
    Type: Grant
    Filed: August 10, 1987
    Date of Patent: May 10, 1988
    Assignee: Tennessee Valley Authority
    Inventors: J. C. Mickus, Cecil P. Harrison, Cullen G. Tittle
  • Patent number: 4743438
    Abstract: An improved process for extending the capabilities of an existing, conventional wet-process phosphoric acid production plant to more effectively utilize phosphate values contained in low purity phosphate rock which process comprises (1) adjustment of the maximum soluble sulfate level in phosphoric acid taken from, for example, the conventional wet-process acid facility prior to reacting same with such low purity phosphate rock, in combination therewith, and (2) control of the parameters of (a) ratio of attack acid to feed rock, (b) reaction temperature, and (c) reaction time. Said improved process effects selective dissolution of calcium and phosphate values from such rock without incurring unwanted and undesired high codissolution of congeneric aluminum and iron impurities therein.
    Type: Grant
    Filed: March 16, 1987
    Date of Patent: May 10, 1988
    Assignee: Tennessee Valley Authority
    Inventors: George A. Kennedy, James R. Lehr
  • Patent number: 4702896
    Abstract: An improved, substantially more energy efficient, thermal treatment process for use on relatively high organic content phosphate rock is herein taught wherein such rock is heated in two stages under controlled conditions to thereby yield an improved calcined product rendered more suitable for subsequent processing into wet-process phosphoric acid by, for example, acidulation with a mixture of phosphoric and sulfuric acids. The two-stage thermal treatment of the instant invention has been demonstrated to be especially beneficial when applied to an apatitic phosphate rock possessing a high content of organic matter and a high degree of carbonate substitution in the apatite crystal lattice thereof.
    Type: Grant
    Filed: September 2, 1986
    Date of Patent: October 27, 1987
    Assignee: Tennessee Valley Authority
    Inventor: Alexander D. Mair
  • Patent number: 4676821
    Abstract: The present invention teaches a technique and provides for apparatus eminently useful for reducing the amount of sulfur currently needed by industry to coat water-soluble fertilizer materials such as, for example, granular or prilled urea. A further advantage of and benefits derived from the practice of the instant invention relates to the production of sulfur-coated urea products which have substantially higher nitrogen values than do urea products produced by prior art processes.
    Type: Grant
    Filed: December 12, 1986
    Date of Patent: June 30, 1987
    Assignee: Tennessee Valley Authority
    Inventors: Larry L. Gullett, Charles L. Simmons
  • Patent number: 4676822
    Abstract: The herein described practice and operating procedures relating to the instant invention have demonstrated the utility and economic advantages of slightly acidic, neutral, and slightly basic fluid fertilizer solutions containing urea and the urease inhibitor thiophosphoryl triamide in preventing or at least substantially reducing the loss of ammoniacal nitrogen from soils to which such fluid fertilizers are often surface applied. The results of said testing procedures also demonstrate a new, novel, and heretofore unknown method of utilizing said thiophosphoryl triamide in conjunction with urea which method circumvents the problem usually encountered in the practice of prior art processes of rapid inhibitor decomposition in solid mixtures with urea.
    Type: Grant
    Filed: July 24, 1986
    Date of Patent: June 30, 1987
    Assignee: Tennessee Valley Authority
    Inventor: Joe Gautney
  • Patent number: 4670038
    Abstract: Test show that 2,2,4,4,6,6-hexaaminocyclotriphosphazatriene, 2-phenoxy-2,4,4,6,6-pentaaminocyclotriphosphazatriene, 2,4-diphenoxy-2,4,6,6-tetraaminocyclotriphosphazatriene and 2,4,6-triphenoxy-2,4,6-triaminocyclotriphosphazatriene (also frequently called phosphonitrilic derivatives) of the formula ##STR1## are highly effective inhibitors of urease activity in agricultural soil systems wherein(1) R.sub.1 . . . R.sub.3 '=NH.sub.2 or(2) R.sub.1 '=R.sub.2 '=R.sub.3 '=R.sub.2 =R.sub.3 =NH.sub.2 and R.sub.1 =OC.sub.6 H.sub.5 or(3) R.sub.1 '=R.sub.2 '=R.sub.3 '=R.sub.3 =NH.sub.2 and R.sub.1 =R.sub.2 =OC.sub.6 H.sub.5 or(4) R.sub.1 '=R.sub.2 '=R.sub.3 '=NH.sub.2 and R.sub.1 =R.sub.2 =R.sub.3 =OC.sub.6 H.sub.5.
    Type: Grant
    Filed: August 21, 1986
    Date of Patent: June 2, 1987
    Assignee: Tennessee Valley Authority
    Inventors: Ramiro Medina, Jack M. Sullivan
  • Patent number: 4648966
    Abstract: An improved phosphate ore beneficiation process wherein phosphate ore containing coarse, weathered dolomite in the flotation feed thereof is subjected to beneficiation as follows: The flotation feed is subjected to a rougher phosphate flotation step wherein it is treated with fatty acid and fuel oil and wherefrom is removed the coarse, weathered dolomite in one or more subsequent cleaner phosphate flotation steps without the use of additional flotation reagents added thereto; subjecting the float from said cleaner phosphate flotation step(s) to a sulfuric acid based partial deoiling step and then to a phosphate-carbonate flotation step wherefrom is collected a first fraction of the phosphate flotation feed values as underflow subjecting the overflow from said phosphate-carbonate flotation step to a sulfuric acid based total deoiling step wherefrom the resulting deoiled material from said total deoiling step is subsequently introduced and subjected to carbonate flotation step(s) using alkyl diphosphonic acid a
    Type: Grant
    Filed: December 2, 1985
    Date of Patent: March 10, 1987
    Assignee: Tennessee Valley Authority
    Inventor: Shaung-shii Hsieh
  • Patent number: 4636303
    Abstract: A phosphate ore beneficiation process wherein phosphate ore containing coarse, weathered dolomite in the flotation feed thereof is subjected to beneficiation as follows: Said feed is sent to rougher phosphate flotation wherein it is treated with fatty acid and fuel oil and wherefrom is removed the coarse weathered dolomite in one or more cleaner phosphate flotations, without the use of additional flotation reagents added thereto, to thereby remove the coarse carbonate, i.e., dolomite fraction, which fraction would not otherwise float in subsequent carbonate flotation. In many instances this process effects reduction of the carbonate, as MgO contamination in the final concentrate, to less than about 1.0 percent by weight. Process feed can be prepared from the coarse pebble waste or the conventional flotation feed of the original phosphate matrix.
    Type: Grant
    Filed: October 7, 1985
    Date of Patent: January 13, 1987
    Assignee: Tennessee Valley Authority
    Inventor: Shuang-shii Hsieh
  • Patent number: 4619684
    Abstract: Process for producing diammonium phosphate (DAP) fertilizer from phosphoric and sulfuric acids, anhydrous ammonia, and water in a specially designed reactor operated at high pressures to granulate diammonium phosphate at low recycle ratios and with relatively small fossil fuel requirement drying per ton of product. Previously operated reactors employed pressures ranging from 0 to 10 psig pressures. This reactor operates at 40 to 80 psig. The process substantially increases production in existing DAP granulation plants and has helped reduce grade deficiencies. Also, use of this reactor for DAP production results in about the same levels of ammonia loss to the scrubber as the prior-art tank preneutralizer, higher operating factors, less maintenance and no transfer pump plugging. Operation is at a temperature of 300.degree. or more .degree.F., while the tank preneutralizer operates normally at 240.degree. F.
    Type: Grant
    Filed: March 24, 1986
    Date of Patent: October 28, 1986
    Assignee: Tennessee Valley Authority
    Inventors: David G. Salladay, Frank P. Achorn
  • Patent number: 4618691
    Abstract: Tests show that 2,2,4,4,6,6-hexaaminocyclotriphosphazatriene, 2-phenoxy-2,4,4,6,6-pentaaminocyclotriphosphazatriene, 2,4-diphenoxy-2,4,6,6-tetraaminocyclotriphosphazatriene and 2,4,6-triphenoxy-2,4,6-triaminocyclotriphosphazatriene (also frequently called phosphonitrilic derivatives) of the formula ##STR1## are highly effective inhibitors of urease activity in agricultural soil systems wherein(1) R.sub.1 . . . R.sub.3 '=NH.sub.2 or(2) R.sub.1 '=R.sub.2 '=R.sub.3 '=R.sub.2 =R.sub.3 =NH.sub.2 and R.sub.1 =OC.sub.6 H.sub.5 or(3) R.sub.1 '=R.sub.2 '=R.sub.3 '=R.sub.3 =NH.sub.2 and R.sub.1 =R.sub.2 =OC.sub.6 H.sub.5 or(4) R.sub.1 '=R.sub.2 '=R.sub.3 '=NH.sub.2 and R.sub.1 =R.sub.2 =R.sub.3 =OC.sub.6 H.sub.5.
    Type: Grant
    Filed: December 31, 1984
    Date of Patent: October 21, 1986
    Assignee: Tennessee Valley Authority
    Inventors: Ramiro Medina, Jack M. Sullivan
  • Patent number: 4617048
    Abstract: A process for producing urea ammonium nitrate (UAN) sodium bentonite suspension from hot urea solution, hot ammonium nitrate solution and dry solid sodium bentonite clay. The dry sodium bentonite clay is added directly to the hot urea solution without the use of expensive chemical dispersants. There is no need for intermediate processing steps involving the dispersion of clay in water, said water normally containing expensive chemical dispersants. After the sodium bentonite has been dispersed in the hot urea solution, then, and only then can the hot ammonium nitrate solution be added. Unexpectedly, the order of addition of the feed material to this process is highly critical. This economical and innovative production process is readily adaptable to existing commercial nitrogen fertilizer production plants and has solved many of the problems which have kept sodium bentonite from being widely used in the production of suspension fertilizers.
    Type: Grant
    Filed: August 26, 1985
    Date of Patent: October 14, 1986
    Assignee: Tennessee Valley Authority
    Inventors: David G. Salladay, Donald L. Kachelman
  • Patent number: 4606897
    Abstract: Phosphate rock, containing appreciable quantities of organic impurities, is thermally treated under controlled conditions to fully utilize the fuel values of the organic matter contained therein. This process is beneficial for treating deposits of unaltered Idaho rock containing both higher grade phosphate rock and lower grade phosphatic shales and recovering therefrom substantially all the phosphate values as a rock product rendered more acceptable for acidulation to wet-process phosphoric acid.
    Type: Grant
    Filed: April 29, 1985
    Date of Patent: August 19, 1986
    Assignee: Tennessee Valley Authority
    Inventor: Alexander D. Mair
  • Patent number: 4601891
    Abstract: An improved process for the production of granular ammonium polyphosphate fertilizer of a nominal 11-56-0 grade resulting from the pressure ammoniation of phosphoric acid without the use of a preneutralizer and using a specially designed pipe reactor to effect coating and granulation of an anhydrous melt onto cascading granules of ammonium polyphosphate with polyphosphate contents thereof ranging from about 15 percent to 30 percent of the total P.sub.2 O.sub.5. The instant invention defines the operating parameters which allow for the practice of a process wherein there is essentially no degradation in the amount of P.sub.2 O.sub.5 values produced as polyphosphate in the melt as said melt is further processed in the remaining steps therein through the step of product recovery, i.e., we have discovered the parameters for operating a process wherein essentially no hydrolysis of the polyphosphate P.sub.2 O.sub.5 values in the melt occurs.
    Type: Grant
    Filed: October 15, 1985
    Date of Patent: July 22, 1986
    Assignee: Tennessee Valley Authority
    Inventors: Kenneth E. McGill, Johnny R. Gamble
  • Patent number: 4600505
    Abstract: A flotation process is taught for beneficiating phosphate ores containing, as impurities, silica and alkaline earth metal carbonates, particularly dolomite. Using a single flotation stage, the phosphate values are recovered in the overflow and quite unexpectedly both the siliceous and the carbonate gangue minerals are simultaneously removed in the underflow. Prior to flotation, surfaces of the minerals in the phosphate ore are selectively sulfidized with an insoluble copper-containing metal sulfide, permitting use of sulfide mineral collecting reagents such as alkyl xanthates in the flotation step to achieve a high degree of selectivity.
    Type: Grant
    Filed: September 9, 1985
    Date of Patent: July 15, 1986
    Assignee: Tennessee Valley Authority
    Inventors: Alexander D. Mair, Myra M. Soroczak
  • Patent number: 4589904
    Abstract: A process for granulating crystalline by-product ammonium sulfate, hereinafter referred to, for the sake of convenience, as A/S, to produce a product having excellent physical and chemical properties as they relate to the storage and handling thereof and also as they relate to the bulk blending of same with other fertilizer blend materials. The method involves introducing the crystalline by-product A/S feedstock, together with recycle material, into a conventional drum ammoniator granulator and granulating the mixture using A/S-sulfuric acid-alum solution and gaseous anhydrous ammonia to bind the crystals together by virtue of the fresh A/S produced and precipitated. Drying in a rotary drum dryer by countercurrent flow of hot gases instead of the more conventional cocurrent gas flow is required.
    Type: Grant
    Filed: August 26, 1985
    Date of Patent: May 20, 1986
    Assignee: Tennessee Valley Authority
    Inventors: Cecil P. Harrison, Cullen G. Tittle
  • Patent number: 4588498
    Abstract: A flotation process is taught for beneficiating phosphate ores containing, as impurities, silica and alkaline earth metal carbonates, particularly dolomite. Using a single flotation stage, the phosphate values are recovered in the overflow and quite unexpectedly both the siliceous and the carbonate gangue minerals are simultaneously removed in the underflow. Prior to flotation, surfaces of the minerals in the phosphate ore are selectively sulfidized with an insoluble copper-containing metal sulfide, permitting use of sulfide mineral collecting reagents such as alkyl xanthates in the flotation step to achieve a high degree of selectivity.
    Type: Grant
    Filed: March 28, 1985
    Date of Patent: May 13, 1986
    Assignee: Tennessee Valley Authority
    Inventors: Alexander D. Mair, Myra M. Soroczak
  • Patent number: H425
    Abstract: Process and Apparatus for preparing O--X--O and O--X--X (i.e., zero nitrogen) suspension fertilizers wherein phosphate rock is acidulated with merchant-grade wet-process orthophosphoric acid. The instant invention requires only a minimal amount of relatively inexpensive equipment. The process comprises a first-charging step wherein a reactor vessel is partially filled with water of formulation, phosphoric acid, and phosphate rock. The resulting mixture is subjected to a digestion step for a predetermined period of time to effect reaction of the acid and phosphate rock added thereto. Said digestion step is subsequently followed by a second-charging step wherein predetermined amounts of potassium chloride and/or suspending agent are added to said reactor vessel.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: February 2, 1988
    Assignee: Tennessee Valley Authority
    Inventors: Herbert W. Norris, Jeffrey L. Boles