US4855061A
Expired / Lapsed
US
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Method and apparatus for controlling the coagulant dosage for water treatment
Assignee: Cpc Engineering Corp
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Filing: 1988-04-26
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Granted: 1989-08-08
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Expires: 2008-04-26
Abstract
Abstract Apparatus for controlling the coagulant dosage rate includes a charge sensor located adjacent a coagulant pump for measuring the net electrical charge on coagulated water before water treatment and a turbidity meter for measuring the effluent turbidity after water treatment. A programmable controller responds to the output signal of the charge sensor to continuously adjust the dosage rate to maintain a set point of charge value in the coagulated water corresponding to a desired effluent turbidity. To maintain calibration of the charge sensor, the controller is also responsive to the output signal of the turbidity meter to adjust the charge value set point as required so that the it corresponds to a preselected effluent turbidity.
Inventors
- 👤 Arnold D. Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:36
CPC Classifications
G; G05; G05D; G05D21/00; G05D21/02; C; C02; C02F; C02F1/00; C02F1/52; C02F1/5209; G01; G01N; G01N33/00; G01N33/18
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
151 words
In a water treatment system including a means for feeding coagulant into water to be treated to form coagulated particles, apparatus for controlling the coagulant dosage comprising: charge sensing means for measuring the net electrical charge of the water after addition of the coagulant; turbidity sensing means for measuring effluent water turbidity after water treatment to remove said coagulated particles and form said effluent water; and control means responsive to the charge sensing means and the turbidity sensing means for controlling the dosage rate of the coagulant feeding means, the control means responsive to the charge sensing means for adjusting the dosage rate of the coagulant feeding means to maintain a set point of charge value to be measured by the charge sensing means and responsive to the turbidity sensing means for adjusting the charge value set point to maintain a preselected turbidity to be measured by the turbidity sensing means.
Claim 2
Dependent Claim
151 words
In a water treatment system including a means for feeding coagulant into water to be treated to form coagulated particles, apparatus for controlling the coagulant dosage comprising: charge sensing means for measuring the net electrical charge of the water after addition of the coagulant; turbidity sensing means for measuring effluent water turbidity after water treatment to remove said coagulated particles and form said effluent water; and control means responsive to the charge sensing means and the turbidity sensing means for controlling the dosage rate of the coagulant feeding means, the control means responsive to the charge sensing means for adjusting the dosage rate of the coagulant feeding means to maintain a set point of charge value to be measured by the charge sensing means and responsive to the turbidity sensing means for adjusting the charge value set point to maintain a preselected turbidity to be measured by the turbidity sensing means.
Claim 3
Dependent Claim
29 words
The apparatus of claim 1 in which the charge sensing means is arranged to measure the net electrical charge of the water after coagulant additions and before water treatment.
Claim 4
Dependent Claim
16 words
The apparatus of claim 1 in which the charge sensing means comprises a streaming current detector.
Claim 5
Dependent Claim
14 words
The apparatus of claim 1 in which charge sensing means comprises a zeta meter.
Claim 6
Dependent Claim
15 words
The apparatus of claim 1 in which the control means comprises a programmable logic controller.
Claim 7
Dependent Claim
9 words
The apparatus of claim 1 comprises a microprocessor-based controller.
Claim 8
Dependent Claim
20 words
The apparatus of claim 1 including flow proportioning means for maintaining a constant proportion of coagulant dosage to water flow.
Claim 9
Dependent Claim
23 words
The apparatus of claim 1 including means for controlling the pH of the water to be treated to maintain a substantially constant pH.
Claim 10
Dependent Claim
153 words
Apparatus for controlling the coagulant dosage added to water flowing in a water treatment system comprising: means for feeding coagulant into water to be treated to form coagulated particles; charge sensing means for measuring the net electrical charge of the water after addition of the coagulant; turbidity sensing means for measuring effluent water turbidity after water treatment to remove said coagulated particles and form said effluent water; and control means responsive to the charge sensing means and the turbidity sensing means for controlling the dosage rate of the coagulant feeding means, the control means responsive to the charge sensing means for adjusting the feed rate of the coagulant feeding means to maintain a set point of charge value to be measured by the charge sensing means and responsive to the turbidity sensing means for adjusting the charge value set point to maintain a preselected turbidity to be measured by the turbidity sensing means.
Claim 11
Dependent Claim
153 words
Apparatus for controlling the coagulant dosage added to water flowing in a water treatment system comprising: means for feeding coagulant into water to be treated to form coagulated particles; charge sensing means for measuring the net electrical charge of the water after addition of the coagulant; turbidity sensing means for measuring effluent water turbidity after water treatment to remove said coagulated particles and form said effluent water; and control means responsive to the charge sensing means and the turbidity sensing means for controlling the dosage rate of the coagulant feeding means, the control means responsive to the charge sensing means for adjusting the feed rate of the coagulant feeding means to maintain a set point of charge value to be measured by the charge sensing means and responsive to the turbidity sensing means for adjusting the charge value set point to maintain a preselected turbidity to be measured by the turbidity sensing means.
Claim 12
Dependent Claim
161 words
Apparatus for controlling the coagulant dosage added to water flowing in a water treatment system, comprising: a coagulant pump having an adjustable feed rate for feeding coagulant into water to be treated to form coagulated particles; a streaming current detector for measuring the net electrical charge of the water after addition of the coagulant and before water treatment to remove coagulated particles and form effluent water; turbidity sensing means for measuring the turbidity of said effluent water after said water treatment; and a programmable controller responsive to the streaming current detector and the turbidity sensing means for controlling the dosage rate of the coagulant pump, the controller responsive to the detector for adjusting the feed rate of the coagulant pump to maintain a set point of charge value to be measured by the detector and responsive to the turbidity sensing means for adjusting the charge value set point to maintain a preselected turbidity to be measured by the turbidity sensing means.
Claim 13
Dependent Claim
161 words
Apparatus for controlling the coagulant dosage added to water flowing in a water treatment system, comprising: a coagulant pump having an adjustable feed rate for feeding coagulant into water to be treated to form coagulated particles; a streaming current detector for measuring the net electrical charge of the water after addition of the coagulant and before water treatment to remove coagulated particles and form effluent water; turbidity sensing means for measuring the turbidity of said effluent water after said water treatment; and a programmable controller responsive to the streaming current detector and the turbidity sensing means for controlling the dosage rate of the coagulant pump, the controller responsive to the detector for adjusting the feed rate of the coagulant pump to maintain a set point of charge value to be measured by the detector and responsive to the turbidity sensing means for adjusting the charge value set point to maintain a preselected turbidity to be measured by the turbidity sensing means.
Claim 14
Independent Claim
115 words
A method of controlling the coagulant dosage added to water flowing in a water treatment system to form coagulated particles comprising: measuring the net electrical charge of the water after addition of the coagulant and before water treatment to remove said coagulated particles and form effluent water; measuring the turbidity of said effluent water after said water treatment; and controlling the dosage rate of the coagulant added to the water in response to measurement of the net electrical charge to maintain a set point of charge value in said water and adjusting the charge value set point in response to measurement of the effluent water turbidity to maintain a preselected turbidity in said effluent water.
Claim 15
Independent Claim
115 words
A method of controlling the coagulant dosage added to water flowing in a water treatment system to form coagulated particles comprising: measuring the net electrical charge of the water after addition of the coagulant and before water treatment to remove said coagulated particles and form effluent water; measuring the turbidity of said effluent water after said water treatment; and controlling the dosage rate of the coagulant added to the water in response to measurement of the net electrical charge to maintain a set point of charge value in said water and adjusting the charge value set point in response to measurement of the effluent water turbidity to maintain a preselected turbidity in said effluent water.
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