Automatic titrator
AssigneeEcolab USA Inc.
InventorsJohn Wilhelm Bolduc, Blake Roberts Otting, Paul R. Kraus, Robert Ryther
Life of this patent
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Abstract
A system and method for performing automated titrations. An automatic titrator utilizes control devices and sensors adapted for various chemical reactions to perform titrations and determine the content of a desired component of a solution. Batch and continuous mode titrations are possible. Titrant is added to a sample either in varying amounts or rates and a titration endpoint is observed via sensors. Control devices detect when the titration endpoint occurs and calculates the desired content. Various reactions within the solution may be suppressed in order to titrate isolated components individually.
Claims31
A method for determining the amount of a desired component in a solution, the method comprising:
- providing an amount of sample;
- providing a light source and an optical sensor with the sample disposed there between, the optical sensor comprising a threshold value;
- adding to the sample at least one reagent so that the sample undergoes a first color change and causes a measurement by the optical sensor to cross the threshold value in a first direction,
- adding a titrant to the sample over time with a controlled titrant pump;
- increasing the amount of titrant added to the sample at a rate that is nonlinear with time until the sample undergoes a second color change wherein the measurement by the optical sensor crosses the threshold value in a second direction opposite the first;
- determining a measure of the titrant necessary to induce the second color change;
- and
- calculating, using the determined measure, the amount of the desired component in the solution.
A system for determining the peracid content in a sample, the system comprising:
- a first reaction vessel for containing a first volume of the sample;
- at least one reagent in fluid communication with the first reaction vessel, the reagent such that when applied to the sample it facilitates a first color change;
- at least one reagent pump associated with the reagent and configured to transport the reagent to the first reaction vessel;
- a first optical arrangement for detecting a color change of a species in the first reaction vessel;
- a titrant in fluid communication with the first reaction vessel, the titrant such that when applied to the combined sample and reagent in sufficient quantity facilitates a second color change;
- at least one titrant pump associated with the titrant configured to transport the titrant to the first reaction vessel;
- a control device in communication with the first optical arrangement, the at least one titrant pump and at least one reagent pump, and configured to
- supply reagent to the first volume of sample contained in the first reaction vessel via the at least one reagent pump until it senses, via the first optical arrangement, the first color change;
- supply titrant via the at least one titrant pump to the sample and reagent combination in the first reaction vessel in an amount which increases at a rate that is nonlinear with time until it senses, via the first optical arrangement, the second color change;
- and
- calculate, based on a controlled quantity associated with supplying the titrant and the amount of titrant supplied to induce the second color change in the first reaction vessel, the peracid content in the sample.
A method for determining the concentration of oxidizer in a transparent sample, the method comprising;
- continuously flowing the sample through a reaction vessel;
- detecting, using an optical arrangement, the transparency of the sample;
- adding to the sample at a first manifold at least one reagent such that the combination of the reagent and the sample produces a first solution;
- adding a titrant to the first solution to form a second solution;
- observing at least one optical property of the second solution using an optical arrangement;
- changing the flow rate of at least one of the sample or the titrant in a first direction until the optical property of the second solution sufficiently changes from a first state to a second state;
- determining a first flow rate of the changed flow rate of the at least one of the sample and the titrant at which the change from the first state to the second state occurred;
- calculating, using the first flow rate, a first measurement of the concentration of oxidizer in the sample;
- changing the flow rate of the at least one of the sample or the titrant in a second direction, the second direction being opposite the first, until the optical property of the second solution sufficiently changes from the second state to the first state;
- determining a second flow rate of the changed flow rate of the at least one of the sample and the titrant at which the change from the second state to the first state occurred;
- and
- calculating, using the second flow rate, a second measurement of the concentration of oxidizer in the sample.
Dependencies are inferred from the claim text.