Patents Assigned to Erco Industries Limited
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Patent number: 4678655Abstract: Effluent acid from a non-evaporating chlorine dioxide-generating process is subjected to diffusion-dialysis across an anion-exchange membrane to preferentially transfer sulphuric acid from the effluent acid stream to a recipient aqueous medium while sodium sulphate remains in a waste stream. The sulphuric acid extracted from the effluent acid stream on this way may be recycled to the chlorine dioxide generator, after concentration, if desired.Type: GrantFiled: August 1, 1984Date of Patent: July 7, 1987Assignee: ERCO Industries LimitedInventor: Zbigniew Twardowski
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Patent number: 4534952Abstract: 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: GrantFiled: February 24, 1984Date of Patent: August 13, 1985Assignee: ERCO Industries LimitedInventors: W. Howard Rapson, Maurice C. J. Fredette
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Patent number: 4526766Abstract: Red amorphous phosphorus is formed by thermal conversion of yellow phosphorus by a process wherein thermal conversion is effected while simultaneously the heat of conversion is permitted to effect evaporation of yellow phosphorus. The evaporated yellow phosphorus is condensed, collected and used in a subsequent conversion batch. The red amorphous phosphorus is obtained substantially free from residual unconverted yellow phosphorus and in a physical form which allows ready further processing to particulate form.Type: GrantFiled: December 13, 1983Date of Patent: July 2, 1985Assignee: ERCO Industries LimitedInventors: Kevin P. Ryan, Carl D. Yank
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Patent number: 4489183Abstract: Particulate red amorphous phosphorus is stabilized against oxidation and phosphine formation by the use of a combination of titanium dioxide or titanium phosphate and an organic resin, usually an epoxy resin, a melamine-formaldehyde resin or a urea-formaldehyde resin.Type: GrantFiled: December 13, 1983Date of Patent: December 18, 1984Assignee: ERCO Industries LimitedInventor: Helena Twardowska
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Patent number: 4473540Abstract: Chlorine dioxide is formed at high efficiency from a solution of acid sodium chlorate at high sulphuric acid normality to which methanol is fed. The reaction medium is at its boiling point under a subatmospheric pressure. Total acid normality values in the range of about 7 to about 9 normal may be used while high efficiency of chlorine dioxide production is maintained.Type: GrantFiled: July 7, 1983Date of Patent: September 25, 1984Assignee: ERCO Industries LimitedInventor: Maurice C. J. Fredette
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Patent number: 4465658Abstract: Chlorine dioxide is formed at high efficiency from a solution of acid sodium chlorate at high sulphuric acid normality in excess of 9 normal to which methanol is fed. The reaction medium is at its boiling point under a subatmospheric pressure. The incidence of white-outs is avoided by feeding chloride ions to the reaction medium, while the efficiency of chlorine dioxide production remains high.Type: GrantFiled: June 13, 1983Date of Patent: August 14, 1984Assignee: Erco Industries LimitedInventor: Maurice C. J. Fredette
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Patent number: 4421598Abstract: The advantages of the serial application of chlorine dioxide and chlorine without intermediate wash during the bleaching of wood pulp in the absence of significant amounts of dissolved organic materials are improved by the presence of small quantities of dissolved chlorine in the chlorine dioxide solution.Type: GrantFiled: March 22, 1982Date of Patent: December 20, 1983Assignee: Erco Industries LimitedInventor: Douglas W. Reeve
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Patent number: 4421728Abstract: Particulate red amorphous phosphorus is stabilized against oxidative degradation to phosphorus acids and phosphine by the use of titanium dioxide or titanium phosphate.Type: GrantFiled: July 7, 1982Date of Patent: December 20, 1983Assignee: ERCO Industries LimitedInventor: Helena Twardowska
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Patent number: 4414193Abstract: Chlorine dioxide for waste water treatment is formed by reaction of sodium chlorate, sodium chloride and sulphuric acid at high acidity while the reaction zone is subjected to subatmospheric pressure and spent reaction medium overflows from the reaction zone. The subatmospheric pressure preferably is applied using a water eductor to which the water to be treated is fed, so that direct contact between the produced gases and the water to be treated is effected.Type: GrantFiled: September 16, 1982Date of Patent: November 8, 1983Assignee: ERCO Industries LimitedInventors: Maurice C. J. Fredette, Gerald Cowley
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Patent number: 4414088Abstract: A novel electrolysis unit (10) for forming sodium chlorate from sodium chloride utilizes a reaction tank (12) and a bank (18) of electrolysis cells wherein the cells (20) are rigidly joined together using a bipolar cell divider plate (42) between adjacent cells. The cells (20) contain interleaved anode (34) and cathode (32) plates which define upwardly-extending electrolysis channels (36). The bank of cells (18) is connected to the reaction tank (18) to receive a plurality of individual flows of electrolyte to the cells (24) and to forward a plurality of individual flows of electrolyzed material (26) to the tank (12). The cell divider plate (42) comprises anodic (64) and cathodic (62) metal layers intimately and integrally connected, by explosive bonding to an electrically-conducting metal layer (66), usually copper.Type: GrantFiled: September 21, 1981Date of Patent: November 8, 1983Assignee: ERCO Industries LimitedInventor: Joseph B. Ford
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Patent number: 4409066Abstract: The adverse effects of dissolved organic material in the aqueous phase of pulp suspensions during bleaching using mixtures of chlorine dioxide and chlorine are overcome by applying the chlorine dioxide and chlorine serially to the pulp in two steps without an intermediate wash. An aqueous solution of chlorine dioxide and chlorine in which the chlorine constitutes from about 6 to about 10% of the total available chlorine of the solution is used in the first step and chlorine is used in the second step. The aqueous solutions are formed by dissolving in water chlorine dioxide and chlorine formed in a chlorine dioxide generator.Type: GrantFiled: March 22, 1982Date of Patent: October 11, 1983Assignee: Erco Industries LimitedInventors: Douglas W. Reeve, W. Howard Rapson
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Patent number: 4406736Abstract: The advantages of the serial application of chlorine dioxide and chlorine without intermediate wash during the bleaching of wood pulp in the absence of significant amounts of dissolved organic materials are improved by the presence of small quantities of dissolved chlorine in the chlorine dioxide solution.Type: GrantFiled: August 17, 1981Date of Patent: September 27, 1983Assignee: ERCO Industries LimitedInventor: Douglas W. Reeve
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Patent number: 4393036Abstract: A mixture of hydrochloric acid and sulphuric acid for use as a feed to a chlorine dioxide generator to provide reactant chemicals therefor is formed by the reaction of chlorine, sulphur dioxide and water. The reaction is effected in the presence of excess chlorine to avoid the presence of dissolved sulphur dioxide in the acid mixture. The proportion of the excess of the chlorine also can be used to control the strength of the acid mixture which can be made without dissolved sulphur dioxide.Type: GrantFiled: November 10, 1981Date of Patent: July 12, 1983Assignee: ERCO Industries LimitedInventor: Maurice C. J. Fredette
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Patent number: 4393035Abstract: A chlorine dioxide generating process is described wherein chlorine formed with the chlorine dioxide is used to form acid reactant for the chlorine dioxide generating process by reaction with sulphur dioxide and water. The substantial evaporation of the water which would otherwise result from the exothermic nature of the reaction is prevented by controlling the temperature of the water during the reaction. In one embodiment, the temperature control is achieved by effecting the reaction in a cooled falling film absorber having integral cooling passages and to which liquid water is fed to form the falling film. In another embodiment, the reaction is effected in a packed tower with a substantial proportion of the product acid being recycled through an external heat exchanger and diluted with water.Type: GrantFiled: November 2, 1981Date of Patent: July 12, 1983Assignee: ERCO Industries LimitedInventor: Maurice C. J. Fredette
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Patent number: 4366120Abstract: Chlorine dioxide solution for use in waste water treatment is produced in an automated small scale plant wherein sodium chlorate solution is reacted with sulphur dioxide at subatmospheric pressure by countercurrent flow in a reaction tower. Water ejectors are used to withdraw gaseous chlorine dioxide from the upper end of the tower and form therefrom chlorine dioxide solution and also to withdraw liquid effluent from the bottom of the tower for discharge. The plant is fully automated to form chlorine dioxide solution in response to inventory requirements. The chlorine dioxide-producing reaction is only permitted to operate if each of a plurality of sensed parameters is within predetermined ranges.Type: GrantFiled: August 27, 1980Date of Patent: December 28, 1982Assignee: Erco Industries LimitedInventor: Gerald Cowley
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Patent number: 4336228Abstract: The entrainment of reaction medium in the vapor phase and the entrainment of gaseous phase in liquid phase are decreased in a chlorine dioxide generator (12) producing a gaseous mixture of chlorine dioxide, chlorine and steam from a boiling reaction medium (14) and wherein generator liquor is recycled with make up chemicals. These results are achieved by generator modifications, which include tangential entry (30) of recycled liquor to the generator (12) in the vapor space (16) above the liquid level in the generator (12), and the provision of a baffle (34, 50) projecting inwardly from the generator wall in the vapor space (16) and arranged to be above the trajectory of the recycled liquor as it enters the generator (12). These modifications enable the generator volume to be decreased substantially, with consequentially decreased capital costs.Type: GrantFiled: September 22, 1980Date of Patent: June 22, 1982Assignee: ERCO Industries LimitedInventor: Gerald Cowley
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Patent number: 4325934Abstract: A highly efficient chlorine dioxide generating process which produces chlorine-free chlorine dioxide and neutral solid phase sodium sulphate from sodium chlorate, sulphuric acid and methanol is described. Solid phase sodium acid sulphate recovered from the high acidity reaction medium is metathesized using controlled quantities of water and controlled quantities of methanol to form the solid phase neutral sodium sulphate. Sulphuric acid recovered from the acid sulphate by the metathesis is recycled to the generator along with a part of the methanol used in the metathesis.Type: GrantFiled: September 22, 1980Date of Patent: April 20, 1982Assignee: Erco Industries LimitedInventors: Richard Swindells, Maurice C. J. Fredette
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Patent number: 4325783Abstract: The adverse effects of dissolved organic material in the aqueous phase of pulp suspensions during bleaching using mixtures of chlorine dioxide and chlorine are overcome by applying the chlorine dioxide and chlorine serially to the pulp in two steps without an intermediate wash. An aqueous solution of chlorine dioxide and chlorine in which the chlorine constitutes from about 6 to about 10% of the total available chlorine of the solution is used in the first step and chlorine is used in the second step. The aqueous solutions are formed by dissolving in water chlorine dioxide and chlorine formed in a chlorine dioxide generator.Type: GrantFiled: November 27, 1979Date of Patent: April 20, 1982Assignee: Erco Industries LimitedInventors: Douglas W. Reeve, W. Howard Rapson
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Patent number: 4299653Abstract: The advantages of the serial application of chlorine dioxide and chlorine without intermediate wash during the bleaching of wood pulp in the absence of significant amounts of dissolved organic materials are improved by the presence of small quantities of dissolved chlorine in the chlorine dioxide solution.Type: GrantFiled: November 29, 1979Date of Patent: November 10, 1981Assignee: ERCO Industries LimitedInventor: Douglas W. Reeve
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Patent number: 4292275Abstract: A modular chlorine dioxide generating unit (10) is disclosed wherein recycled reaction mixture passes along a flow path (18) internally of the generator vessel (12) out of direct fluid flow communication with the reaction medium (13) from the lower end (16) of the vessel (12) to a discharge point in the vapor phase (15) above the liquid level (13) in the generator vessel (12).Type: GrantFiled: May 22, 1980Date of Patent: September 29, 1981Assignee: ERCO Industries LimitedInventor: James H. Forster