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.
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
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
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.
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.
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.
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.
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
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.