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:
Jun. 23, 1992
Filed:
Oct. 15, 1990
Alan D Randolph, Tucson, AZ (US);
Arizona Technology Development Corporation, Tucson, AZ (US);
Abstract
A crystallizer control method and apparatus that generate control signals to manipulated process parameters on the basis of on-line information derived from the measurement of the crystal population in a selected size range in the crystallizer slurry. According to one embodiment of the invention, a particle counter probe is immersed directly into the fines removal circuit of the crystallizer for on-line measurement of crystal population in the 16 to 32 micron size range. The data so collected are then used directly in a standard proportional controller apparatus to manipulate certain operating parameters, such as fines removal rate and feed rate, to effect the desired result. Applying this model-independent control method to a KCl crystallizer, the steady-state conditions of the crystal size distributions were reestablished after an upset in approximately half the time required when no control was applied. The maximum perturbation of the performance index in the controlled case was approximately 65 percent of the magnitude registered without control. The perturbation of the crystal population in the 16-32 micron range was approximately half of that seen without control.