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:
Sep. 28, 1999
Filed:
Nov. 28, 1997
Applicant:
Inventors:
Louis T Barry, Skillman, NJ (US);
Mark B McCormick, Weston, CT (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F23N / ; F23G / ;
U.S. Cl.
CPC ...
110188 ; 110185 ; 110186 ; 110190 ; 110204 ; 110206 ; 110225 ; 110227 ; 110342 ; 110345 ; 110346 ;
Abstract
A multiple hearth furnace having a drying zone, a combustion zone and a cooling zone includes a recirculation loop that recycles exhaust gas from the drying zone to the cooling zone. In some embodiments, a first control loop including a temperature measurement device that measures temperature in the combustion zone controls fan speed of a recirculation fan that drives the recirculation loop. A second control loop monitors recirculation fan temperature and overrides the first control loop if the recirculation fan temperature exceeds a predetermined maximum. A third control loop controls air flow into the furnace.