Enhanced graded low NOx pulverized coal burner

Abstract

A classification strengthened low NOX pulverized coal burner comprises a primary air passage (1), a straight flow inner secondary air passage (2) and a rotating flow inner secondary air passage (3). The pulverized coal is separated at a spray nozzle into an inside-concentration and outside-dilution structure and is sprayed into a hearth through a pulverized coal equalizer (5) and a pulverized coal separator (6), which are arranged inside the primary air passage (1). Inner secondary air is provided with a straight flow air inlet and a rotating flow air inlet and then sprayed into the hearth after being mixed in the air passage. The volume of the straight flow air is controlled through a pull rod (8), so that the rotating flow strength of the inner secondary air can be controlled. Both of primary air outlet and secondary air outlet are provided with a structure of spray nozzle expanded-cone (7) with a certain angle, so that the timely mixing of secondary air and the pulverized coal is effectively controlled. Meanwhile, the water cooling wall of the spray nozzle is maintained in oxidization atmosphere for a long time. The slag formation and high-temperature corrosion on the water-cooling wall in the burner area can be effectively avoided.

Description

technical field [0001] The invention relates to the technical field of power plant boilers, in particular to an intensified graded low NOx pulverized coal burner suitable for coal-fired boilers. Background technique [0002] With the increasingly stringent national control of nitrogen oxide emissions from power plant boilers, a combustion system technology with full furnace air staging and low NOx burners has been widely used, and various schools of low NOx swirl and once-through burners have been formed. technology. [0003] As far as the wall-mounted boiler is concerned, in order to effectively reduce nitrogen oxides in the furnace, the staged combustion and low NOx emission technology of the whole furnace adopts the method of dividing all the air (oxygen) supplied to the furnace for the combustion of pulverized coal into two parts. Part of the air is injected into the furnace from the nozzle of the main burner in the lower furnace to meet the oxygen required for the earl...

AI Technical Summary

Problems solved by technology

[0004] However, while applying the above technology to meet the national pollutant emission reduction requirements, especially when it is applied to the transformation of the original traditional burner, there are currently contradictory problems: 1. After adopting the staged combustion low NOx burner, often Will cause combustion delay, resulting in high fly ash combustibles

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