Chlorine Dioxide Patents (Class 423/477)
  • Patent number: 4542008
    Abstract: A continuous process for the production of chlorine dioxide by the electrolysis of an aqueous solution of sodium chlorite is provided. The process comprises electrolyzing the aqueous sodium chlorite solution to produce chlorine dioxide which dissolves to produce an aqueous solution of NaClO.sub.2 containing chlorine dioxide. The aqueous solution of sodium chlorite-containing ClO.sub.2 is passed through a photometric cell to measure the chlorite ion concentration as a function of the color produced by the ClO.sub.2 -NaClO.sub.2 -H.sub.2 O system. Chlorine dioxide gas is removed from the aqueous solution and recovered.The novel process of the present invention employs solutions containing low, accurately controlled concentrations of sodium chlorite ion which when electrolyzed avoid the formation of by-products such as a dark colored chlorine dioxide complex and sodium chlorate.
    Type: Grant
    Filed: October 3, 1983
    Date of Patent: September 17, 1985
    Assignee: Olin Corporation
    Inventors: Italo A. Capuano, Diane L. DeFelice
  • Patent number: 4534952
    Abstract: Chlorine dioxide, particularly for water treatment but useful in other applications of chlorine dioxide, such as the bleaching of pulp, is produced in an enclosed reaction zone filled with chlorine dioxide-generating reaction medium under sufficient pressure to prevent chlorine dioxide from forming a continuous gaseous phase and the resulting aqueous solution of chlorine dioxide in spent reaction medium is discharged to a recipient aqueous medium, such as a flowing water body to be treated, without the formation of gaseous phase chlorine dioxide.
    Type: Grant
    Filed: February 24, 1984
    Date of Patent: August 13, 1985
    Assignee: ERCO Industries Limited
    Inventors: W. Howard Rapson, Maurice C. J. Fredette
  • Patent number: 4504442
    Abstract: The use of gaseous chlorine dioxide to sterilize surfaces, especially the gas impermeable surfaces of implements commonly employed in the medical sciences, such as those formed from porcelain, ceramics, metal, plastics and glass. The contaminated surfaces are contacted with an effective amount of gaseous chlorine dioxide for a time sufficient to kill bacterial spores at a temperature which does not overly exceed ambient temperature.
    Type: Grant
    Filed: October 19, 1982
    Date of Patent: March 12, 1985
    Assignee: Scopas Technology Corporation
    Inventors: David H. Rosenblatt, Aaron A. Rosenblatt, Joseph E. Knapp
  • Patent number: 4292292
    Abstract: The present invention is directed to a chlorine dioxide generation process. The Novel process of this invention utilizes concentrated hydrochloric acid solution reacted with concentrated sodium chlorite solution, without prior dilution of either reactant. Resulting in consistent high efficiency with respect to yield and chemical consumption.
    Type: Grant
    Filed: May 30, 1980
    Date of Patent: September 29, 1981
    Assignee: Rio Linda Chemical Company
    Inventors: Bruce W. Hicks, Jerry D. Hicks
  • Patent number: 4250144
    Abstract: A system for generating chlorine dioxide for use as a disinfectant in water or wastewater treatment, the system output including a percentage of chlorine at an acceptably low level, thereby avoiding the deleterious effect of chlorine in the disinfection process. The system is provided with a source of chlorine gas and a source of aqueous sodium chlorite, both of which are fed into a reactor to generate chloride dioxide therein. The output of the reactor is coupled to an ejector operated by a water stream to create a vacuum which draws chlorine dioxide from the reactor into the ejector to dilute the chlorine dioxide before it is supplied to a process being treated. The resultant negative pressure in the reactor acts to draw the chlorine gas therein from the source through a vacuum regulator which maintains the flow of chlorine gas into the reactor at a constant rate and acts to cut off the supply of chlorine in the absence of negative pressure.
    Type: Grant
    Filed: June 14, 1979
    Date of Patent: February 10, 1981
    Assignee: Fischer & Porter Company
    Inventor: Brian J. Ratigan
  • Patent number: 4247531
    Abstract: The present invention is directed to a chlorine dioxide generation apparatus and to a method of generating chlorine dioxide utilizing this apparatus. The novel apparatus comprises a generator having a mix and dwell premix chamber interconnected with a venturi preferably, or to some other source of vacuum, undiluted reactants are permitted to mix and react in the premix chamber, prior to any dilution as by water or other fluid flowing through a venturi eductor to deliver the generated chlorine dioxide to its place of storage or utilization.
    Type: Grant
    Filed: August 13, 1979
    Date of Patent: January 27, 1981
    Assignee: Rio Linda Chemical
    Inventor: Bruce Hicks
  • Patent number: 4234446
    Abstract: Apparatus and continuous-flow process for producing a solution of chlorine dioxide by reaction between a hypochlorite, a chlorite and an acid in a gas generator-reactor comprising a plurality of separate reaction chambers interconnected in series arrangement, in which liquid reactants flow through successive stages, but chlorine dioxide is prevented from flowing between stages. A water-driven venturi eductor removes gaseous reaction products and maintains a vacuum within the reaction chambers. Gaseous reaction products are mixed with the eductor exhaust water. A separate eductor may be provided to remove liquid products of reaction from the gas generator-reactor.
    Type: Grant
    Filed: October 9, 1979
    Date of Patent: November 18, 1980
    Assignee: Kenneth T. Place
    Inventor: Daniel Ramras
  • Patent number: 4104190
    Abstract: Chlorine dioxide is generated from aqueous liquids container alkali metal or alkaline earth metal chlorites, and compounds which liberate chlorine in water. Dry, stable, solid compositions, in one or two parts, can be made from these and other ingredients.
    Type: Grant
    Filed: March 21, 1977
    Date of Patent: August 1, 1978
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Stephen R. Hartshorn
  • Patent number: 4013761
    Abstract: The present invention is directed to a chlorine dioxide generation apparatus and a method of generating chlorine dioxide using the apparatus. The novel apparatus includes a generation vessel having leak-inhibiting solvent weld joints with reducing couplings which form an inlet and outlet. The reducing couplings advantageously have surfaces which form an angle of at least 110.degree. with the vessel walls to create a geometry which prevents chemicals buildup during operation of the apparatus.
    Type: Grant
    Filed: January 23, 1976
    Date of Patent: March 22, 1977
    Assignee: Olin Corporation
    Inventors: William J. Ward, Kenneth E. Gasper