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:
Aug. 30, 1977
Filed:
Oct. 28, 1975
Soren Bent Christiansen, Copenhagen Valby, DK;
F. L. Smidth & Co., Cresskill, NJ (US);
Abstract
A method is disclosed for heat treating granular or pulverulent raw material wherein the raw material is directed to a heat exchanger having at least two preheating units operating in parallel, each preheating unit having at least a first preheating stage and at least a lowermost calcination stage to effect a preheating and at least partial calcination of the material. The preheated, at least partially calcined material is fed from the heat exchanger into a kiln and undergoes a sintering process in the kiln. The sintered material is directed from the kiln into a cooling means in which cooling air is directed in a manner to effect a heat exchange between the material and the cooling air. The method further comprises dividing the heated cooling air exiting the cooling means and directing a portion of the heated cooling air to at least one of the calcination stages of the heat exchanger and directing a portion thereof to the kiln in excess of that required to support combustion of fuel in the kiln for the sintering process thereby intensifying the effectiveness of a material cooling zone within the kiln proper. Hot kiln exit gases are directed to at least one of the calcination stages and fuel is directed to at least one of the calcination stages to support combustion with preheated cooling air to provide supplementary heating of the material and at least partially calcining of the preheated material. An apparatus for practicing the inventive method is also disclosed.