A bottom-up cocurrent combustion furnace for the production of synthetic microspheres by thermal expansion of glass particles is provided having improved characteristics with regard to anti-fouling, process efficiency, and yield. The disclosed furnace uses preheated combustion air to preheat the feed material and to convey the feed material in a dilute phase transport regime to a burner. The combustion air, fuel, and feed material are premixed prior to being injected though the burner. The feed material rapidly expands as it is ejected through the burner and through a flame and then rapidly cools to solidify the microspheres. Additional features are provided to prevent the furnace from fouling by keeping the feed material away from the furnace walls, removing feed material that adheres to the furnace walls, and collecting feed material that agglomerates or does not expand.
Please note there is up to 60 days of latency in this Status indicator for certain status conditions. You can obtain up-to-date Status indicator readings by ordering PAIR for the file.
An application with the status "Published" (which means it is pending) may be recently abandoned, but not yet updated to reflect its abandoned status. However, an application filed less than one year ago is unlikely to be abandoned.
A patent with the status "Granted" may be recently expired, but not yet updated to reflect its expired status. However, it is highly unlikely a patent less than 3.5 years old would be expired.
An application with the status "Abandoned" is almost always current, but there is a small chance it was recently revived and the status not yet updated.
This priority date is an estimated earliest
priority date and is purely an estimation. This date should not be
taken as legal conclusion. No representations are made as to the
accuracy of the date listed. Please consult a legal professional
before relying on this date.