Abstract: An apparatus and method of making a filamentary pad for improved mist elimination and mass transfer comprising a plurality of layers of mesh, each layer of mesh having a plurality of mesh openings defined therein. A plurality of preferential gas flow openings, each having an area larger than any of the areas of said mesh openings absent said preferential gas flow openings, are defined within at least two layers of mesh. The plurality of layers of mesh are vertically stacked to form the filamentary pad. The preferential gas flow openings provide preferential low-resistance paths for gas flow.

Abstract: An improved random-dumped packed bed for effecting inter-phase heat and mass transfer. The packed bed is a plurality of a first packing size substantially uniformly mixed and co-mingled with a plurality of the suitable second larger packing size. The mixed bed so formed provides the additional surface area and mass transfer capacity of the plurality of the added first smaller packing size while maintaining the gas and liquid limiting flow capacity of a bed of the second larger packing size absent the smaller first packing size.

Abstract: Toxic metal vapor phase compounds, and in particular, mercury and cadmium, are removed from waste incinerator combustion gases by contact with dry alkaline material and dry activated carbon followed by solids separation. The resulting gas is subjected to quench/wet scrubbing with recycle hydrochloric acid solution formed in situ by absorption of HCl from the gas. Blowdown liquid withdrawn from the recycle acid liquor, may be recycled to the incinerator or further treated by neutralization, precipitation, and filtration of the precipitated toxic metals.

Abstract: A method and apparatus for minimizing the environmental release of acids and toxic organic compounds from a waste incinerator-air pollution control train. The apparatus comprises an incinerator, a gas cooling means such as a waste heat boiler or quench chamber, a means for the partial removal of acid gases and dioxins by contact with either finely-divided alkaline solids or alternatively, by an alkaline solution in a spray drier-absorber, a dry solids collection means such as a fabric filter or electrostatic precipitator, a wet scrubber means for residual metal, dioxin/acid gas removal and an induced draft fan. In the method of this invention, the final wet scrubber stage operates without alkaline neutralization, but under scrubber acid concentrations and operating conditions that provide an exhaust gas within compliance limits of emission regulations. The contaminated liquor blowdown from the wet scrubber, which contains toxic organics and acids, is recycled back into the incinerator.

Abstract: Toxic metal vapor phase compounds, and in particular, mercury and cadmium, are removed from waste incinerator combustion gases by contact with dry alkaline material and dry activated carbon followed by solids separation. The resulting gas is subjected to quench/wet scrubbing with recycle hydrochloric acid solution formed in situ by absorption of HCl from the gas. Blowdown liquid withdrawn from the recycle acid liquor, may be recycled to the incinerator or further treated by neutralization, precipitation, and filtration of the precipitated toxic metals.

Abstract: Environmental release of carcinogenic polychlorinated dibenzo-dioxins and polychlorinated dibenzo-furan compounds that typically result from combustion of materials containing chlorine or hydrochloric acid-generating components is minimized by preferential sorption of the precursor reactants on sorbents added to exhaust gas at high temperatures containing such precursors prior to conversion of the precursors to carcinogenic compounds normally occurring as the exhaust gas is cooled.

Abstract: A method and apparatus for maximizing gas flow and liquid loading capacities of filamentary mist eliminators by means of appended impermeable drainage channels or gutters which serve to augment collection of liquid drainage from the mist eliminator, protect the drainage liquid from re-entrainment by gas friction, and transport and discharge the drainage liquid to the low gas velocity region adjacent to the vessel walls.

Abstract: A method and apparatus for minimizing the environmental release of acids and toxic organic compounds from a waste incinerator-air pollution control train. The apparatus comprises an incinerator, a gas cooling means such as a waste heat boiler or quench chamber, a means for the partial removal of acid gases and dioxins by contact with either finely-divided alkaline solids or alternatively, by an alkaline solution in a spray drier-absorber, a dry solids collection means such as a fabric filter or electrostatic precipitator, a wet scrubber means for residual metal, dioxin/acid gas removal and an induced draft fan. In the method of this invention, the final wet scrubber stage operates without alkaline neutralization, but under scrubber acid concentrations and operating conditions that provide an exhaust gas within compliance limits of emission regulations. The contaminated liquor blowdown from the wet scrubber, which contains toxic organics and acids, is recycled back into the incinerator.

Abstract: A nitric acid producing plant including an absorber and a closed vessel. Nitric acid having nitrous acid in solution is produced in the absorber by reacting to the oxides of nitrogen derived from the decomposition of ammonia with water. There is also an oxygen cylinder which supplies oxygen under pressure differential to the vessel. The pressure of the stagnant oxygen in the vessel exceeds atmospheric pressure. The plant also includes means for passing the nitric acid solution from the absorber to the vessel under positive differential pressure and means for recycling to the absorber the product of the reaction of the nitric acid solution and the oxygen. The liquid which is recycled to the absorber absorbs NO at a higher rate than NO.sub.2.

Abstract: This invention relates to a novel gas-liquid contacting apparatus and method utilizing recycle spray contact trays disposed within a substantially vertical vessel. Each contact tray contains one or more housings defined by upstanding vertical wall members, said housings being open to gas flow at top and bottom. Within the housings, liquid spray is continuously generated by means of gas flowing upward past a first array of horizontally spaced-apart gas venturi-generating liquid conductors. Liquid flows from the tray floor outside the housing through the liquid conductors, is distributed into the gas, and is entrained upward as spray by the gas venturi action. Horizontally-disposed foraminous or perforated flow-restrictive elements, vertically spaced apart, mounted on top of the housings, cause the liquid spray to coalesce and regenerate at the first flow-restrictive barrier element which occupies the cross-sectional area of the vertical housing.

Abstract: This invention relates to a novel gas-liquid contacting apparatus and method utilizing recycle spray contact trays disposed within a substantially vertical vessel. Each contact tray contains one or more housings defined by upstanding vertical wall members, said housings being open to gas flow at top and bottom. Within the housings, liquid spray is continuously generated by means of gas flowing upward past a first array of spaced-apart gas venturi-generating liquid conductors. Liquid flows from the tray floor outside the housing through the liquid conductors, is distributed into the gas, and is entrained upward as spray by the gas venturi action. The major apart of the liquid spray is captured by an array of horizontal open-ended foraminous or perforated tubes, in substantial side-by-side contact with each other. The spray issuing laterally from the tubes impinges on the vessel walls and liquid therefrom drains downward or falls by gravity to the tray floor, where the process is repeated.

Abstract: The mixture of aqueous nitric and nitrous acids which is produced by the absorption of nitrogen oxides with water in the manufacture of nitric acid is conducted to a closed vessel, where the acid mixture is reacted with oxygen, preferably under pressure, and is then returned to the absorber. This treatment has been found to enhance the absorption of the nitric oxide (NO) component of the gas mixture of NO and NO.sub.2 which is supplied to the absorber in the production of nitric acid. Normally, nitric oxide has a low solubility in the mixture of nitric and nitrous acids. Because nitric oxide oxidation is the controlling factor in the operation of nitric acid plants, this enhanced absorption provides for more efficient and economic nitric acid manufacture, as well as for the reduction of emissions of nitrogen oxides in the acid plant tail gases.The same invention is also applicable to the removal of nitrogen oxides from emissions generated in processes other than nitric acid manufacture.

Abstract: A method for removing acid gases, particularly the sulfur oxides and hydrochloric acid from a hot flue gas without substantially cooling or humidifying the latter consists in withdrawing a small stream of the flue gas, preferably the purified gas, and introducing it into a stream of humid gas consisting of steam and/or humid air containing dispersed therein a finely-divided, porous, alkaline earth metal hydroxide upon which surface is adsorbed at least a monomolecular layer of water, and thereby reacting carbon dioxide in the withdrawn portion of the flue gas with the pore surfaces of the hydroxide to form an alkaline earth metal carbonate thereon. The so-formed reactant in the humid gas is then brought into contact with the main flow of hot flue gas, thereby removing acid gases from the flue gas, the solid reaction products and excess reactant thereafter being separated from the flue gas in a baghouse or electrostatic precipitator, and the so-treated flue gas being discharged to the atmosphere.

Abstract: A method and apparatus for removing acid gases such as halogen acids and sulfur oxides from a hot flue gas by contacting the gas with a finely-divided, pre-moistened and partially-agglomerated, intimate mixture of a solid alkaline reagent and a deliquescent compound. The dry akaline reactang/deliquescent compound mix is pre-conditioned by exposure to a gas of controlled humidity for a time sufficient to cause partial liquefaction of the deliquescent compound. Contact at controlled humidity conditions may be effected in a treating vessel or in a transport duct prior to injection into the hot flue gas. Alternatively, the dispersed deliquescent compound may be separately liquefied prior to mixing with the alkaline solids. Liquefaction of the deliquescent compound is achieved by controlling the partial pressure of water vapor in the conditioning gas mixture at a level higher than the equilibrium vapor pressure of the liquefied deliquescent material or its highest hydrate.

Abstract: Apparatus for treating fluids flowing at high velocity, for mass and heat transfer, for gas-liquid contacting and for contaminant particulate, mist or fume separation, including a plurality of perforated or unperforated cylinders arrayed staggered in rows perpendicular to the direction of flow of the fluid. The elements are spatially separated from each other. Diagonal by-pass flow through the array is blocked by a partition extending from each element generally parallel to the direction of flow of fluid bisecting the space between a pair of elements of an adjacent row with the elements of the pair symmetrically spaced with respect to the partition.Also, a method of removing contaminants from gas by passing the gas through this array between and injecting a liquid into the array. Capture of the contaminants by the drops is effected because of the difference in acceleration of each as the contaminated gas passes in and out of the gap between each cylinder and its adjacent partitions.

Abstract: Prilling apparatus for producing prills of ammonium nitrate or urea in which a diverging shroud extends from each prilling head. Means for supplying ammonia is connected to the shroud. The prills pass through a quiescent zone of ammonia in the shroud and the generation of fumes from the apparatus is suppressed. In addition, the prills are coated with a layer of ammonia and are more readily cooled.

Abstract: A gas scrubber and/or mist eliminator for high-velocity gas in the range between about 1,000 to 2,500 feet per minute. The gas flows horizontally through a duct or conduit in which a plurality of generally vertical, high-voidage, fibrous, non-capillary, free-draining bodies are interposed. The gas both passes through and is deflected by the bodies and its mist and/or other components are captured and drained by the bodies. Reentrainment of the drained liquid flowing out of the bodies is prevented. The bodies may be arrays of rows of separate baffles or they may be mounted on vanes.

Abstract: The emission of fumes is suppressed from a prilling tower for producing prills of ammonium nitrate or urea by conducting particles from a spray of a melt of the material countercurrent through a stream of air. The spray of the material, as it leaves the prilling head is passed through a stagnant atmosphere of ammonia. In addition, the particles of the spray are coated with ammonia and their cooling by the countercurrent air stream is accelerated. To produce the ammonia atmosphere, a shroud is provided about the spray nozzle or nozzles into which gaseous ammonia is injected.

Abstract: Gas containing nitrogen oxides is treated in two separate stages. In the first stage, the nitrogen oxides in the gas are reacted with sulfurous acid. The gaseous product of this reaction is reacted with an alkaline solution, typically caustic alkali. As a result of these treatments, the nitrogen oxides are converted into neutral salts.

Abstract: Apparatus for treating fluids flowing at high velocity, for mass and heat transfer, for gas-liquid contacting and for contaminant particulate, mist or fume separation, including a plurality of perforated or unperforated cylinders arrayed staggered in rows perpendicular to the direction of flow of the fluid. The elements are spatially separated from each other. Diagonal by-pass flow through the array is blocked by a partition extending from each element generally parallel to the direction of flow of fluid bisecting the space between a pair of elements of an adjacent row with the elements of the pair symmetrically spaced with respect to the partition.Also, a method of removing contaminants from gas by passing the gas through this array between and injecting a liquid into the array. Capture of the contaminants by the drops is effected because of the difference in acceleration of each as the contaminated gas passes in and out of the gap between each cylinder and its adjacent partitions.