Burner structure

Abstract

To provide a low combustibility fuel firing burner that can ensure high ignition performance and combustion stability even if a gas flow rate is changed along with changes in boiler load or the like. A low combustibility fuel firing burner separates a pulverized low combustibility fuel supplied together with an air with a separator, distributing the separated fuel to a rich portion nozzle and a lean portion nozzle provided in a furnace, and burning the fuel, in which a variable control part such as a core or a flow adjusting / blocking valve is provided in at least one of a high-particle-concentration gas pipe extending from a downstream side of the separator and communicating with the rich portion nozzle and a low-particle-concentration gas pipe extending from the downstream side of the separator and communicating with the lean portion nozzle.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a low combustibility fuel firing burner applicable to various types of combustion apparatuses that burn a low combustibility fuel such as a pulverized coal boiler. [0003] This application is based on Japanese Patent Application No. 2006-286692, the content of which is incorporated herein by reference. [0004] 2. Description of Related Art [0005] Hitherto, a low combustibility fuel firing burner that burns a pulverized low combustibility fuel (hereinafter referred to as “burner”) has been used in pulverized coal boilers fired with a low combustibility fuel such as anthracite or petroleum coke in a fine powder form. [0006] For example, as shown in FIGS. 4 and 5, a burner 10A of the related art, which burns a fuel that is pulverized coal obtained by pulverizing anthracite in a furnace 1 of a boiler is composed of a pulverized coal-air mixture system provided in the burner center and supp...

AI Technical Summary

Benefits of technology

The present invention provides a low combustibility fuel firing burner that can ensure high ignition performance and combustion stability even if gas flow rate changes occur. The burner has a variable control part that can adjust the flow path sectional area to optimize performance under different operating conditions. The burner also has a separator that can adjust the separation efficiency and optimize the gas flow rate. The burner has a hardwearing finish to improve wear resistance. Additionally, the burner has a unique design that prevents interference of flames and slagging on the furnace wall. Overall, the low combustibility fuel firing burner ensures high ignition performance and combustion stability.

Problems solved by technology

However, according to the above related art, when a gas flow rate is changed along with change in boiler load or the like, an ignition performance or combustion stability might be affected thereby.

In particular, in the case of using a low combustibility fuel, an ignition performance or combustion stability is affected also by interference of flames of adjacent nozzles.

Therefore, it is difficult to attain a desired distribution rate for the rich portion nozzle 24 and the lean portion nozzle 26.

Further, if a burner is not used during partial load operations or a spare burner is used, there is a fear of backflow of a gas from the lean nozzle pipe 25 to a direction of the separator 20A due to a negative pressure.

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