US5378374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lime addition system for water treatment
Assignee: Individual
•
Filing: 1993-10-15
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Granted: 1995-01-03
•
Expires: 2013-10-15
Abstract
Abstract A system for the preparation of a lime slurry and metering of the slurry, which prevents scaling and plugging of equipment and piping. The elimination of scaling and ease of metering are achieved by a combination of process steps in an automated operating sequence. The system is particularly adaptable to the addition of lime to municipal water systems for reduction of the acidity of the water.
Inventors
- 👤 John N. Andersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:53
CPC Classifications
C; C01; C01F; C01F11/00; C01F11/02; C02; C02F; C02F1/00; C02F1/52; C02F1/529; C02F1/66; C02F1/72; C02F1/76; C02F5/00; C02F5/02; C02F5/06; C02F1/008; C02F2209/00; C02F2209/06
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
173 words
A process for the control of the acidity of municipal water supplies which comprises: (a) introducing into a first agitated vessel, which contains a lime slurry heel, a mixture of hydrated lime and water in an amount sufficient to obtain a slurry having a lime concentration from about 12 to about 24% by weight; (b) transferring the slurry from the first vessel into a second agitated holding vessel containing a lime slurry heel and circulating the slurry in the second vessel; (c) providing a third agitated vessel containing a dilute lime slurry having a concentration from about 1 to 4% by weight; (d) continuously feeding the dilute slurry to the municipal water supply at a rate sufficient to obtain a substantially neutral pH while periodically restoring the dilute lime slurry level in the third agitated vessel by addition of a controlled quantity of slurry from the second agitated vessel and water to maintain the desired slurry concentration and also a slurry level which is not less than about 75% of the vessel capacity.
Claim 2
Dependent Claim
173 words
A process for the control of the acidity of municipal water supplies which comprises: (a) introducing into a first agitated vessel, which contains a lime slurry heel, a mixture of hydrated lime and water in an amount sufficient to obtain a slurry having a lime concentration from about 12 to about 24% by weight; (b) transferring the slurry from the first vessel into a second agitated holding vessel containing a lime slurry heel and circulating the slurry in the second vessel; (c) providing a third agitated vessel containing a dilute lime slurry having a concentration from about 1 to 4% by weight; (d) continuously feeding the dilute slurry to the municipal water supply at a rate sufficient to obtain a substantially neutral pH while periodically restoring the dilute lime slurry level in the third agitated vessel by addition of a controlled quantity of slurry from the second agitated vessel and water to maintain the desired slurry concentration and also a slurry level which is not less than about 75% of the vessel capacity.
Claim 3
Dependent Claim
67 words
A process according to claim 1, wherein the pH of the lime slurry-adjusted municipal water supply is continuously monitored by electronic means and signals generated by upward deviations from a set point pH value are utilized for temporary downward adjustment of the flow of slurry introduced from the second agitated vessel to the third agitated vessel until the desired pH value is restored in the water supply.
Claim 4
Dependent Claim
28 words
A process according to claim 1, wherein the slurry from the second agitated vessel is transferred to the third agitated vessel by means of a positive displacement pump.
Claim 5
Dependent Claim
28 words
A process according to claim 1, wherein the slurry from the second agitated vessel is transferred to the third agitated vessel by means of a progressive cavity pump.
Claim 6
Dependent Claim
30 words
A process according to claim 1, wherein a measured quantity of a chlorinating agent is introduced into the first vessel along with the measured amounts of hydrated lime and water.
Claim 7
Dependent Claim
13 words
A process according to claim 5, wherein the chlorinating agent is calcium hypochlorite.
Claim 8
Dependent Claim
14 words
A process according to claim 5, where in the chlorinating agent is sodium hypochlorite.
Claim 9
Dependent Claim
12 words
A process according to claim 5, wherein the chlorinating agent is chlorine.
Claim 10
Dependent Claim
30 words
A process according to claim 1, wherein a measured quantity of a chlorinating agent is introduced into the slurry being transferred from the first vessel into the second agitated vessel.
Claim 11
Dependent Claim
13 words
A process according to claim 9, wherein the chlorinating agent is calcium hypochlorite.
Claim 12
Dependent Claim
13 words
A process according to claim 9, wherein the chlorinating agent is sodium hypochlorite.
Claim 13
Dependent Claim
12 words
A process according to claim 9, wherein the chlorinating agent is chlorine.
References Cited (Backward Citations)
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US4320012A
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US4465597A
Cited
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-01-02 | 1998-07-04 | 1999-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-02 | 2002-07-04 | 2003-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-02 | 2006-07-04 | 2007-01-03 | $7700.00 | Window Closed / Lapsed |