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:
Mar. 23, 1993
Filed:
Nov. 07, 1990
Achim Hartmann, Pulheim, DE;
Kronos (USA), Inc., Hightstown, NJ (US);
Abstract
A process for the production of titanium dioxide through the reaction of vaporous TiCl.sub.4 with oxygen under a pressure of between 2.4 and 3.4 bar, and a corresponding apparatus are used to achieve long permanent operation times. The oxygen required is indirectly preheated to between 850.degree. and 1000.degree. C. In a reaction chamber closed at one end, configured inside for advantageous flow and lined at least partly with refractories, the indirectly preheated oxygen is further heated by direct contact with very hot combustion gases of an auxiliary flame to temperatures, as is required, for the spontaneous reaction with the TiCl.sub.4 introduced downstream into the reaction chamber. Through an annular passage in the inner peripheral wall of the reaction chamber directly at its front wall, the indirectly preheated oxygen enters the chamber uniformly distributed over its circumference, and the oxygen flow is controlled to obtain a Reynolds' number of between 15,000 and 20,000 in the annular passage and to obtain a ratio of Reynolds' number to inner diameter, in millimeters, of the reaction chamber of between 25 and 50 to 1.