Patent · US Expired

Apparatus and method for reduction of NOx emissions from a fluid bed combustion system through staged combustion

US4308810A · kind A · utility

13Cited by
10References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 9, 1980
Grant dateJan 5, 1982
Priority date
Expiry dateApr 9, 2000

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF27B15/14
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

Apparatus and method for the reduction of nitrogen oxides (NOx) in the emissions of a fuel burning fluidized bed combustion system. Using a staged combustion technique, an overfire air inlet is provided in the freeboard zone above the bed. In the first stage, residual oxygen (O.sub.2) in the off-gas just above the bed is held in the 0.4 to 0.8% range by the actual coal and air rates. In the second stage, carbon monoxide (CO) and unburned hydrocarbons, both present in the first stage off-gas, are combined with additional air using the overfire air inlet. CO levels in the final effluent are reduced with little or no increase in NOx emissions.

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