Patent · US Expired

Method of operating a multiple hearth furnace

US6832564B2 · kind B2 · utility

4Cited by
10References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 24, 2003
Grant dateDec 21, 2004
Priority date
Expiry dateOct 24, 2023

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF27B9/185
  • WIPO fieldThermal processes and apparatus
  • WIPO sectorMechanical engineering

Abstract

A method of operating a multiple hearth furnace with a plurality of vertically aligned hearth floors includes feeding a first material onto the uppermost hearth floor and moving it over the hearth floor before it falls through a drop hole onto the next lower hearth floor. The first material is processed in this way from hearth floor to hearth floor to the lowermost hearth floor. A second material is fed onto one of the hearth floors to be mixed into the first material. This second material is moved separately from the first material in a separate annular zone of the hearth floor onto which it is fed before it is mixed into the first material, providing an efficient thermal preconditioning of the second material prior to mixing it with the first material without requiring any supplemental equipment.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.