Patent · US Expired

Pulverized coal combustion method

US5003891A · kind A · utility

13Cited by
3References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 26, 1990
Grant dateApr 2, 1991
Priority date
Expiry dateFeb 26, 2010

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF23K2201/10
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

The known pulverized coal combustion method including the steps of separating pulverized coal mixture gas ejected from a vertical type coal grinder into thick mixture gas and thin mixture gas by a distributor, and injecting these thick and thin mixture gases, respectively, through separate burner injecting ports into a common furnace to make them burn, is improved so as to reduce both an unburnt content in the ash and a nitrogen oxide concentration in exhaust gas while maintaining an excellent ignition characteristic. The improvements reside in that an air-to-fuel ratio of the thick mixture gas is regulated to within the range of 1-2, while an air-to-fuel ratio of the thin mixture gas is regulated to within the range of 3-6, and the range of a degree of pulverization of the pulverized coal is regulated to 100 mesh residue 1.5% or less. The degree of pulverization of the pulverized coal fed to the distributor is regulated either by adjusting the rotational speed of a rotary type classifier in the grinder or by adjusting the angles formed between classifying vanes, rotating about the axis of the rotary type classifier, and the direction of rotation.

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