US 5,422,014 A · Automatic chemical monitor and control system

Abstract

An automatic system to precisely maintain bactericidal action in a reservoir of water equipped with a recirculation system, such as a swimming pool, decorative fountain, spa, cooling water reservoir or the like. The automatic system includes: a service loop which bypasses a portion of the recirculating water past sensors which measure the pH and oxygen reduction potential (ORP) of the water and in which acid and halogen are injected by a chemical feed unit; an electronics unit for determining the injection quantity of the acid and/or halogen needed to restore pH and ORP to stored set-points, and for controlling the chemical feed unit in response to the injection time determination; and an optional telecommunication unit for reporting process control status to a remote location and allowing modification of the process parameters, selection of operating modes, and performance of diagnostic tests from the remote location. The service loop is constructed so that the acid injection results in water having a low pH flowing turbulently over the sensors and the halogen injector to keep the sensors and the halogen injector free from scale buildup and to produce data to the electronics unit from which the response characteristics of the sensors can be determined.

Claims87

Dependent claims

A monitoring and controlling system for a reservoir of water that has a recirculation system for recirculating the water in the reservoir, said monitoring and controlling system including:

a service loop positioned in the recirculation system to bypass a portion of the water flowing therethrough, said service loop including:
means to inject acid into the water flowing in said service loop;
a pH sensor positioned downstream of said means to inject acid to produce a signal representative of the pH of water flowing there past;
means to inject halogen as a bactericide into the water flowing in said service loop positioned downstream of said means to inject acid;
and
an oxygen reduction potential sensor positioned downstream of said means to inject acid and upstream of said means to inject halogen, to produce a signal representative of the oxygen reduction potential of the flow of water out of said service loop;
and
means to sense flow of water through said service loop and to produce a signal representative of the existence of flow of water through said service loop.

5 more elements

A reservoir of water including:

water quality maintenance means;
a recirculation pump for recirculating water from said reservoir through said water quality maintenance means and back to said reservoir, said water quality maintenance means including:
a service loop connected to the recirculation system so that at least a portion of the recirculating water passes therethrough, said service loop including:
means to inject acid into the recirculating water in said service loop;
a pH sensor positioned downstream of said means to inject acid to produce a signal representative of the pH of recirculating water thereat;
means to inject bactericidal halogen into the recirculating water in said service loop positioned downstream of said means to inject acid;
and
an oxygen reduction potential sensor positioned downstream of said means to inject acid and upstream of said means to inject bactericidal halogen, to produce a signal representative of the oxygen reduction potential of the recirculating water thereat;
means to sense flow of the recirculating water and to produce a flow signal representative of the existence of a quantity of flow of recirculating water through said service loop;
and
controller means connected to receive said signals representative of the pH, the oxygen reduction potential, and the existence of flow of recirculating water and to produce therefrom, an acid inject signal to said means to inject acid to cause said means to inject acid to inject acid into the recirculating water to maintain the pH of the reservoir water in a range, and a bactericidal halogen inject signal to said means to inject bactericidal halogen to cause said means to inject bactericidal halogen to inject bactericidal halogen into the recirculating water to maintain effectiveness of the bactericidal halogen in the reservoir water.

8 more elements

The reservoir of water as defined in claim wherein said reservoir includes:

a first water storage area having:
a first water storage capacity;
a second water storage area having:
a second water storage capacity smaller than said first water storage area;
valve means to switch said recirculation pump between recirculating water of said first water storage area and recirculating water of said second water storage area, said computer control means including:
memory means including:
data representative of the expected responses of said first and second water storage areas to the addition of chemical therein;
a startup routine that:
first determines that water is recirculating in said service loop before allowing injection of acid or bactericidal halogen;
causes first amounts of acid and bactericidal halogen to be injected based on said second water storage capacity;
measures the response to injection of the first amounts of acid and bactericidal halogen of the recirculating water;
compares the measured response to injection of the first amounts of acid and bactericidal halogen of the recirculating water to:
determine therefrom whether the injections of the first amounts of acid and bactericidal halogen took place from the response of said pH sensor thereto;
and
determine therefrom whether said pH and said oxygen reduction potential sensors are operating properly from the response thereof to the injection of the first amount of acid and bactericidal halogen;
after a delay, compares the measured response to injection of the first amounts of acid and bactericidal halogen of the recirculating water to:
determine therefrom the long term response of the recirculating water to injection of the first amounts of acid and bactericidal halogen and thereby determine the state of said valve means from the long term response of the recirculating water to the injection of the first amounts of acid and bactericidal halogen;
and
adjusts said acid and halogen inject signals to maintain proper bactericide effectiveness in said first water storage area when said valve means are determined to be recirculating water of said first water storage area.

16 more elements

Water quality maintenance means for at least one reservoir of water open to biological contaminants that includes at least one water recirculation system, which recirculates water in the at least one reservoir, said water quality maintenance means including:

sensor means connected to the at least one water recirculation system so that at least a portion of the recirculating water passes adjacent thereto, said sensor means including:
means that produce a recirculation output signal when the at least one recirculation system is recirculating water;
a pH sensor that produces an pH output signal representative of the pH of recirculating water thereat;
and
an oxygen reduction potential sensor that produces an ORP output signal representative of the oxygen reduction potential of the recirculating water thereat;
chemical feed means connected to the at least one water recirculation system so that at least a portion of the recirculating water passes adjacent thereto, said chemical feed means including:
an acid feed system to controllably feed acid into the recirculating water of the at least one water recirculation system;
and
a halogen feed system to controllably feed halogen into the recirculating water of the at least one water recirculation system;
and
controller means connected to receive said recirculation output signal, said pH output signal, and said ORP output signal and to produce therefrom, an acid feed signal to said acid feed system to cause said acid feed system to feed acid in the recirculation water to lower the pH of the water in the at least one reservoir to a first range, and a halogen feed signal to said halogen feed system to cause said halogen feed system to feed halogen in the recirculation water to raise the oxygen reduction potential of the water in the at least one reservoir to a second range, said sensor means further including:
a temperature sensor that produces a temperature output signal representative of the temperature of the recirculating water thereat, said controller means using said temperature output signal to compensate said pH and ORP output signals for temperature.

9 more elements

Water quality maintenance means for at least one reservoir of water that includes at least one water recirculation system, which recirculates water in the at least one reservoir, said water quality maintenance means including:

sensor means connected to the at least one water recirculation system so that at least a portion of the recirculating water passes adjacent thereto, said sensor means including:
means that produce a recirculation output signal when the at least one recirculation system is recirculating water;
a pH sensor that produces an pH output signal representative of the pH of recirculating water thereat;
and
an oxygen reduction potential sensor that produces an ORP output signal representative of the oxygen reduction potential of the recirculating water thereat;
chemical feed means connected to the at least one water recirculation system so that at least a portion of the recirculating water passes adjacent thereto, said chemical feed means including:
an acid feed system to controllably feed acid at a rate into the recirculating water of the at least one water recirculation system, said acid feed system including:
a supply of liquid acid;
an acid port positioned for feeding liquid acid into the recirculating water;
and
means to move said liquid acid from said supply of liquid acid into the recirculating water through said acid port, said acid port being spaced slightly upstream from said pH and oxygen reduction potential sensors, said means to move said liquid acid having sufficient rate capacity to substantially change the pH of the recirculating water at said pH sensor;
and
a halogen feed system to controllably feed halogen at a rate into the recirculating water of the at least one water recirculation system, said halogen feed system including:
a supply of liquid halogen;
a halogen port positioned for feeding liquid halogen into the recirculating water;
and
means to move said liquid halogen from said supply of liquid halogen into the recirculating water through said halogen port, said halogen port being spaced slightly upstream from said pH sensor and downstream from said oxygen reduction potential sensor, said means to move said liquid halogen having sufficient rate capacity to substantially change the pH of the recirculating water at said pH sensor;
and
controller means connected to receive said recirculation output signal, said pH output signal, and said ORP output signal and to produce therefrom, an acid feed signal to said acid feed system to cause said acid feed system to feed acid in the recirculation water for time sufficient to lower the pH of the water in the at least one reservoir to a range, and a halogen feed signal to said halogen feed system to cause said halogen feed system to feed halogen in the recirculation water for time sufficient to raise the oxygen reduction potential of the water in the at least one reservoir to a range.

16 more elements

An automatic system to maintain bactericidal action in a reservoir of water equipped with means for recirculating water, the automatic system including:

a first sensor responsive to pH;
a second sensor responsive to bactericidally effective halogen;
a service loop which bypasses a portion of the recirculating water past said first and second sensors;
acid injection means that on command inject acid upstream of said first and second sensors at a rate that establishes a first pH at least as low as a second pH at said first and second sensors when acid is being injected thereby;
halogen injection means that on command inject halogen upstream of said first sensor and downstream of said second sensor;
and
electronics means for determining the injection times of the acid and halogen needed to restore pH and bactericidally effective halogen to stored set-points, and for controlling said acid and halogen injection means in response to said injection time determination.

4 more elements

Dependencies are inferred from the claim text.

Automatic chemical monitor and control system

Life of this patent

Automatic chemical monitor and control system

Life of this patent

Abstract

Claims87