The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 20, 1999
Filed:
Feb. 21, 1995
Kevin T O'Dougherty, Minneapolis, MN (US);
Travis A Lemke, St. Paul, MN (US);
Donald C Grant, Exelsior, MN (US);
FSI International, Inc., Chaska, MN (US);
Abstract
A chemical blending system for blending two or more constituent chemicals to a desired concentration. One embodiment of the system includes a mix tank, a recirculation line having an inlet and an outlet in the tank, and a pump in the recirculation line for recirculating and mixing the blended chemical. A source of diluent is fluidly coupled to the mix tank through a diluent inlet and supply line. A source of concentrated chemical is fluidly coupled to the recirculation line through a concentrated chemical inlet, supply line, and an adding valve located in the recirculation line between the inlet and pump. A conductivity-type sensor in the recirculation line provides continuous measurements of the blended chemical concentration. A titration analyzer is coupled to the recirculation line to provide periodic blended chemical concentration measurements. A programmable logic control system including a processor and associated memory is coupled to the adding valve, conductivity-type sensor and titration analyzer. A blending control program and process control values are stored in the memory. The processor executes the blending control program and controls the concentrate adding valve as a function of the concentration measurements provided by the conductivity-type sensor and titration analyzer to blend the chemical to the desired concentration.