Method and system for increasing calsium and remelting flyash in boiler and high temperature desulfurizing in boiler

Abstract

The present invention provides a boiler fly ash calcium-increasing remelting-intrafurnace desulfurizing method and its system. Said method includes the following steps: (1), making the fly ash discharged by boiler be passed through remelting system, then making collection, pressurization and distribution; (2), making the fly ash having need of increasing calcium undergo the process of calcium-increasing treatment; and (3),spraying the calcium-increased fly ash into the furnace cavity to make secondary combustion, remelting and desulfurization. Said system includes boiler coal-feeding belt system, powder-making system, combustor, boiler, dust-remover, boiler blower and stack, etc. Said system also includes a fly ash calcium-increasing system connected with boiler and a fly ash remelting system connected with dust-remover, and the fly ash remelting system is connected with said fly ash calcium-increasing system.

Description

technical field [0001] The invention relates to a boiler fly ash remelting-in-furnace high-temperature desulfurization method and system thereof. Background technique [0002] Sulfur dioxide emitted during coal combustion is the main source of sulfur dioxide pollution in my country, and fly ash is one of the sources of solid waste and dust pollution. [0003] The fly ash remelting technology is to use the dry fly ash (generally containing a certain amount of residual combustible carbon and free CaO) captured in the ash hopper of the dust collector at the end of the liquid slagging boiler (or cyclone furnace) that burns pulverized coal. The conveying device is used to send it back to the high-temperature zone of the original boiler furnace, so that the residual combustibles in the fly ash are combusted for a second time, and the heat is recovered to realize coal saving in the boiler. [0004] Patent application CN 00129744.9 discloses a liquid slagging furnace desulfurizatio...

AI Technical Summary

Problems solved by technology

Since the original CaO content in the fly ash is less than 20%, the desulfurization efficiency in the furnace is low

In order to increase the desulfurization effect in the furnace, adding limestone to the coal fired in the boiler is often counterproductive, which will cause frequent fire extinguishing and accidental shutdown of the boiler

[0006] The above-mentioned technologies lack an automatic control system and a sulfur dioxide monitoring system, and cannot accurately and timely control the calcium content of fly ash and the desulfurization process in the furnace, and the overall desulfurization effect of the system is poor

[0007] To sum up, so far, the use of fly ash remelting technology for efficient desulfurization in the furnace is still an unsolved problem

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