Abstract: A flange alignment tool comprises a body portion having a first, relatively flat surface disposed for abutting engagement with a rear surface of a pipe flange and a second, curvilinear surface adjacent the first surface and shaped for complementary engagement with a curvilinear neck portion of the pipe flange adjacent the rear surface thereof. First and second spaced apart aligning pins extend through the body portion and include projecting flange-engaging pin ends positioned for alignment with an adjacent pair of through apertures in the flange. Resilient springs urge the aligning pins in a predetermined direction for encouraging positive engagement of the flange-engaging pin ends with the through apertures.

Abstract: A baffle for protecting a bottom bearing assembly used as a stabilizer for an agitator shaft operating in a tank-like vessel containing a liquid hostile to bearing components. The baffle defines a pressurized gaseous chamber for isolating the bearing from the liquid in the vessel. Gas under pressure delivered to and maintained in the chamber prevents invasive entry of liquid from the vessel. The apparatus includes an open top bearing-encircling casing which is sealed at its lower end to a bottom wall of the vessel. A pipe in the form of an inverted bucket coaxial with and sleeved over to overlap and encircle an open top of the casing is open at its lower end and is sealed at its upper end to the agitator shaft for rotation therewith. Spaced radially outwardly of an outer wall of the casing, the pipe defines with the casing a restricted annular channel.

Abstract: A novel cleaning assembly for a dryer feed chute comprises a shaft, a housing in which said shaft is rotatably mounted, a carriage for carrying the housing and the shaft member, drive mechanism for rotating the shaft, and an oscillating chain for moving the housing and hence the shaft in the longitudinal direction. The oscillating mechanism includes control structure for providing longitudinal movement of the housing and the shaft from a first position to a second position and thereafter back to the first position to complete a cycle.

Abstract: A method for maintaining a preselected concentration of non-condensible gases in a condenser is disclosed. A compressor supplies the condenser with compressed ammonia. The compressed ammonia includes non-condensible gases. At least a portion of the compressed ammonia condenses, forms condensed ammonia and exits the condenser. A pressure controller operates an automatic valve to vent at least a portion of the non-condensible gases from the condenser. A temperature element senses the condensed ammonia temperature and sends a signal, based upon the condensed ammonia temperature, to the pressure controller. The pressure controller uses the signal to reduce the pressure of the condenser from a predetermined value to a computed value estimated to be necessary to maintain the preselected concentration of non-condensible gases in the condenser.

Abstract: A converter igniter is provided for igniting a converter screen assembly which acts as a catalyst for vapor phase oxidation of ammonia in a nitric acid reduction process. The igniter includes an elongate gas delivery tube and structure for sealably mounting the gas delivery tube with one end thereof within the vapor phase oxidation chamber. An igniting structure is provided at the end of the elongate gas tube includng a spark plug completely recessed within the end of the tube and a plurality of apertures in the tube end for producing a diffuse flame. An elongate rod-like conductor is concentrically mounted within the gas delivery tube and electrically and physically isolated therefrom by means of a concentrically mounted surrounding insulator structure.

Abstract: A process for producing fertilizer-grade phosphoric acid is disclosed. In the process, a rock slurry is produced from a predetermined quantity of phosphate rock and a predetermined quantity of pond water neutralized with ammonia. A predetermined rate of sulfuric acid is added to the rock slurry to produce a reaction mixture. The improvement comprises maintaining an excess of sulfate ion in the reaction mixture.

Abstract: Disclosed are after-treatment processes and apparatus for synthesis plants, particularly urea and ammonium nitrate plants, but applicable also to various other plants in which the synthesis reaction does not go to substantial completion. In such plants product is fed to an evaporator for concentration and then to a solidification stage. The vaporous overhead stream from the evaporator contains entrained synthesis product, one or more unreacted starting materials, and solvent (usually H.sub.2 O). It is condensed, and the condensate is brought into mass and heat exchange relationship with the vaporous overhead stream from the evaporator substantially without material transfer of solvent to the condensate stream. The condensate stream is thereby enriched in synthesis product, heat is added to it, and unreacted starting material is desorbed from it. The product-enriched condensate is delivered to the solidification stage for processing there.

Abstract: An ammonium nitrate particle removal apparatus is joined with an exhaust gas flow of a nitrogen oxides abatement system as utilized in a nitric acid producing plant for removing ammonium nitrate particles carried in the gas flow. The apparatus includes a filter element for receiving the gas flow and substantially trapping the ammonium nitrate particles. Injection nozzles inhabit a conduit which delivers the exhaust gas flow to an inlet of the filter and inject a water mist into the gas flow which mist acts to irrigate the filter. As a result of this irrigation, the trapped ammonium nitrate particles go into solution and drop by the action of gravity to a tank or reservoir below the filter element, where the solution may be recovered for other uses as desired.

Abstract: This application discloses a method of wet grinding crude phosphate rock containing clay minerals and the like impurities. The procedures of the invention produce a rock slurry of enhanced fluidity and a desired degree of economy; and the principles of the invention may be applied to rock slurries after size-reduction. The method of the invention contemplates introducing coarsely sized, crude phosphate rock with component clay minerals or the like into a grinding mill together with a suitable quantity of water and with an amount of a calcium-free alkaline amendment or additive material which is adequate to establish and maintain a pH of at least about 8.5 in the mixture.