Patent US3954403A successfully refreshed from Google Patents.
US3954403A
Expired / Lapsed
US
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Removal of phosphates in drain line of laundry tub by chemical precipitation
Assignee: Colgate Palmolive Co
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Filing: 1973-10-01
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Granted: 1976-05-04
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Expires: 1993-10-01
Abstract
Abstract A washing machine or dishwasher includes means for admixing with waste wash water a suitable chemical compound to convert the soluble phosphate in the wash water to insoluble form before discharge of the waste solution to a sewer, drain or other means of disposal. Among the useful chemical compounds employed are calcium chloride, calcium hydroxide and aluminum sulfate, which convert soluble phosphates, including tripolyphosphate and pyrophosphate salts, to insoluble materials, which may be removed from the effluent. Also within the invention are accessories for use with conventional washing apparatuses for effecting the insolubilization reaction, and corresponding processes.
Inventors
- 👤 Joseph George Ferraro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:17
CPC Classifications
D; D06; D06F; D06F39/00; D06F39/02; D06F39/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
246 words
A method of washing items with detergent containing soluble phosphate which comprises contacting in a tub means, the items to be washed with washing solution containing such detergent and, after completion of washing, removing the washing solution from the washed items, conveying said washing solution to a conduit running from said tub means to a sewer, drain or other means of disposal, supplying a suitable reactive chemical compound to said washing solution in said conduit, reacting the soluble phosphate in the washing solution with said reactive chemical compound in said conduit before discharge of the washing solution to said sewer drain or other means of disposal, so as to convert the soluble phosphate to insoluble form, said supplying step being effected by providing a Venturi section in said conduit for dispensing said reactive chemical compound and conveying said washing solution at a sufficient rate to create a vacuum in said Venturi section that draws a sufficient quantity of said reactive chemical compound into said washing solution, said reacting step being effected by the continuous addition to said washing solution from said Venturi section of from a stoichiometric proportion to a 200% excess, based on the soluble phosphate content of the removed washing solution, of a suitable precipitant salt chosen from the group consisting of oxides, hydroxides and soluble salts of calcium, aluminum and iron in an aqueous medium at a concentration of about 2 to about 80 weight percent to insolubilize substantially all of said phosphate.
Claim 2
Independent Claim
246 words
A method of washing items with detergent containing soluble phosphate which comprises contacting in a tub means, the items to be washed with washing solution containing such detergent and, after completion of washing, removing the washing solution from the washed items, conveying said washing solution to a conduit running from said tub means to a sewer, drain or other means of disposal, supplying a suitable reactive chemical compound to said washing solution in said conduit, reacting the soluble phosphate in the washing solution with said reactive chemical compound in said conduit before discharge of the washing solution to said sewer drain or other means of disposal, so as to convert the soluble phosphate to insoluble form, said supplying step being effected by providing a Venturi section in said conduit for dispensing said reactive chemical compound and conveying said washing solution at a sufficient rate to create a vacuum in said Venturi section that draws a sufficient quantity of said reactive chemical compound into said washing solution, said reacting step being effected by the continuous addition to said washing solution from said Venturi section of from a stoichiometric proportion to a 200% excess, based on the soluble phosphate content of the removed washing solution, of a suitable precipitant salt chosen from the group consisting of oxides, hydroxides and soluble salts of calcium, aluminum and iron in an aqueous medium at a concentration of about 2 to about 80 weight percent to insolubilize substantially all of said phosphate.
Claim 3
Dependent Claim
70 words
A method according to claim 1 wherein, after reaction of the compound and the soluble phosphate to produce insoluble phosphate, the insoluble phosphate is removed from the used washing solution by filtration or other separatory method and the washing solution, free of phosphate or of substantially lower phosphate content than when discharged from the washing machine or dishwasher, is then discharged to a sewer, drain or other means of disposal.
Claim 4
Dependent Claim
60 words
A method according to claim 2 wherein the soluble phosphate is an alkali metal pyrophosphate, tripolyphosphate or orthophosphate, the reactive chemical compound is an at least slightly water soluble compound of a metal which forms an insoluble phosphate or polyphosphate, and the chemical reaction and filtration operations take place at or near the location at which the items are washed.
Claim 5
Dependent Claim
75 words
A method according to claim 3 wherein the items being washed are laundry, washing is effected in an automatic washing machine, the reactive chemical is an oxide, hydroxide or soluble salt of calcium, aluminum or iron in an aqueous medium, at a concentration of about 2 to 80%, so as to convert substantially all the soluble phosphate to insoluble phosphate and to remove from 75 to 100% thereof from the waste wash water being discharged.
Claim 6
Dependent Claim
81 words
A method according to claim 4 wherein the washing solution comprises synthetic organic detergent of the anionic and/or nonionic type with pentasodium tripolyphosphate builder, the reaction between the chemical compound and the soluble phosphate in the wash water being discharged is at a temperature of about 15° to 80° C., the time of reaction is from 1 second to 1 hour and the wash water discharged after filtration contains less than 10 parts per million of phosphorus in water soluble form.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-04 | 1979-11-03 | 1980-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-04 | 1983-11-03 | 1984-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-04 | 1987-11-03 | 1988-05-04 | $7700.00 | Window Closed / Lapsed |