Abstract: A process for producing an aqueous hypochlorous acid solution reacts droplets of an alkali metal hydroxide solution containing greater than 50 percent by weight of the alkali metal hydroxide with chlorine gas. The reaction produces a gaseous mixture of dichlorine monoxide, chlorine, hypochlorous acid vapor and water vapor, and solid particles of alkali metal chloride. The solid particles of alkali metal chloride are separated and the gaseous mixture condensed at a temperature in the range of from about -33.degree. C. and about -5.degree. C. to produce the aqueous hypochlorous acid solution. The process of the invention results in increased yields of hypochlorous acid and provides an economic basis for increased production capacity. The aqueous hypochlorous acid solutions produced are highly pure and as a result have significantly improved stability.

Abstract: An elongated, generally vertically extending cocurrent reactor vessel for the production of hypochlorous acid by the mixing and reaction of a liquid alkali metal hydroxide and a gaseous halogen is provided wherein an atomizer is mounted near the top of the reactor vessel to atomize the liquid alkali metal hydroxide into droplets in the vessel. The vessel has a spraying and reaction zone immediately beneath the atomizer and a drying zone beneath the spraying and reaction zone to produce a gaseous hypochlorous acid and a substantially dry solid salt by-product.

Abstract: An elongated, generally vertically extending cocurrent reactor vessel for the production of hypochlorous acid by the mixing and reaction of a liquid alkali metal hydroxide and a gaseous halogen is provided wherein a nozzle is mounted near the top of the reactor vessel beneath the gas injector to spray the liquid alkali metal hydroxide in droplets so that the halogen gas can be absorbed into the surface of the droplets simultaneously with water evaporation in the vessel. The vessel has a spraying and reaction zone immediately beneath the atomizer and a drying zone beneath the spraying and reaction zone.

Abstract: Apparatus for the separation of a solid salt by-product from the product gaseous hypohalogenated acid of a reactor is disclosed which is effective to separate particles ranging in size from about 0.5 to about 50 microns. The reactor mixes an aqueous alkali metal hydroxide and a gaseous halogen to produce the hypohalogenated acid product and solid salt by-product which are discharged from the reactor into the separation apparatus.

Abstract: A method of using an elongated, generally vertically extending cocurrent reactor vessel for the production of hypochlorous acid by the mixing and reaction of a liquid alkali metal hydroxide and a gaseous halogen is provided wherein an atomizer is mounted near the top of the reactor vessel to atomize the liquid alkali metal hydroxide into droplets in the vessel. The vessel has a spraying and reaction zone immediately beneath the atomizer and a drying zone beneath the spraying and reaction zone to produce a gaseous hypochlorous acid and a substantially dry solid salt by-product.

Abstract: An elongated, generally vertically extending reactor vessel for the production of hypochlorous acid by the mixing and reaction of a liquid alkali metal hydroxide and a gaseous halogen is provided with solids discharge handling apparatus connected to the bottom to remove the solid by-product. The discharge handling apparatus uses the solids to effect a seal to prevent the intrusion of outside air into the reactor and the escape of halogen and product gas to the outside atmosphere.

Abstract: A calcium hypochlorite composition consists essentially of at least 75 percent by weight of Ca(OCl).sub.2, from about 6 to about 14 percent by weight of water, and less than 1.5 percent by weight of an alkali metal chloride. The novel composition provides increased amounts of sanitizing and disinfecting to, for example, water bodies while remaining safe with respect to thermal decomposition. Further, the composition reduces the rate of chlorine evolution during storage.

Abstract: A process for producing hypochlorous acid by reacting an aqueous solution of an alkali metal hydroxide in droplet form with gaseous chlorine to produce hypochlorous acid vapor and solid alkali metal chloride particles in which the improvement comprises employing molar ratios of gaseous chlorine to the alkali metal hydroxide of at least about 22:1.The process achieves high yields of hypochlorous acid by minimizing side reactions including the formation of chlorate as an impurity in the alkali metal chloride particles produced.The hypochlorous acid solution produced contains from about 35 to about 60 percent by weight of HOCl, a dissolved chlorine concentration of less than about 2 percent by weight, and is substantially free of alkali metal ions and chloride ions.