Powdered coal burner and burning device using said powdered coal burner

Abstract

To provide a pulverized coal burner and a combustion apparatus using the same, for obtaining sufficient restriction of the generation of NOx by facilitating the expansion of NOx reduction area. A plurality of plate-shaped members 30 (10 mm thick) are arranged radially in a pulverized coal nozzle 11. A high concentration part 37 is formed radially in primary air containing pulverized coal to the injected from the pulverized nozzle 11 with the concentration of the pulverized coal distribute circumferentially, so that quicker ignition of the pulverized coal is accomplished by the fast propagation of flame passing through the high concentration part 37. The speeding up of the consumption of oxygen enables expansion of a reduction area formed near a burner to reduce the generation of NOx. As a result of the quicker ignition, since combustion time in a furnace can be increased, unburned components in the ash is lowered and combustion rate is increased.

Description

technical field [0001] The present invention relates to a pulverized coal burner for burning pulverized coal which is conveyed by airflow and combusted together with the airflow, in particular, relates to a pulverized coal burner which can effectively reduce the concentration of nitrogen oxides and the use of this pulverized coal burner combustion device. Background technique [0002] Most of the NO produced during pulverized coal combustion X (nitrogen oxides) is the so-called fuel NO X , is produced by the oxidation of nitrogen contained in coal, however, in the early combustion stage, through thermal decomposition reactions, nitrogen contained in coal is converted into HCN (hydrogen cyanide) and NH 3 (ammonia) in the gas phase. [0003] Thus, at high oxygen concentrations, these nitrogen compounds are oxidized to NO X , and in the case of low oxygen concentration, it is reduced to harmless N 2 (nitrogen). [0004] At present, in order to reduce the NO produced by co...

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Problems solved by technology

[0033] That is to say, in order to suppress the production of NO during pulverized coal combustion X , first of all the pulverized coal must be ignited rapidly, but, in the above-mentioned prior art example, because the pulverized coal concentration increases in the periphery, therefore, the pulverized coal flow ignites rapidly in the peripheral part of the pulverized coal nozzle injection, but in the middle The fuel concentration is lower, the ignition is delayed, and the formation of NO X Restoration area

[0034] In addition, in the above-mentioned examples of the prior art, when the jetted coal flow forms a vortex, under the action of centrifugal force, the pulverized coal is dispersed in the radial direction after being sprayed out from the pulverized coal nozzle. In this case, due to the The dispersed pulverized coal in the high oxygen concentration area burns at the periphery of the pulverized coal flow, so the NO X concentration increases

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