Fly ash circulating device and circulating fluidized bed boiler comprising same

Abstract

The invention provides a fly ash circulating device and a circulating fluidized bed boiler comprising the same. The fly ash circulating device comprises a middle ash bin, a feeding machine and a pneumatic conveying device; the middle ash bin is used for containing fly ash to be circulated, an inlet of the middle ash bin is connected with a dust remover, and an outlet of the middle ash bin is connected with a coal feeding port of a hearth through a fly ash circulating pipeline; the feeding machine is arranged on the fly ash circulating pipeline and is used for supplying fly ash to the hearth from the middle ash bin; and the pneumatic conveying device is arranged on the fly ash circulating pipeline and used for conveying fly ash provided by the feeding machine into the hearth. By means of the device, the carbon content of the fly ash can be reduced, and the economic benefit and the environmental protection benefit are improved.

Description

technical field [0001] The invention belongs to the technical field of boilers, and in particular relates to a fly ash circulation device and a circulating fluidized bed boiler comprising the same. Background technique [0002] Circulating fluidized bed (CFB) boilers have the advantages of wide fuel adaptability and good environmental protection, and are developing rapidly in our country. After the coal is burned in the furnace, the high-temperature flue gas, ash and carbon particles produced enter the cyclone separator for separation. Among them, the larger particles are captured by the separator and enter the standpipe and returner to return to the furnace. The small particles fly to the furnace. The ash enters the dust collector from the central cylinder of the separator, and then is sent into the ash storage by the dust collector. [0003] At present, most fluidized bed boilers have a large deviation between the actual operating coal quality and the initial design coal ...

AI Technical Summary

Problems solved by technology

However, through the practical application of many projects, it is found that the technology of sending fly ash into the furnace through the secondary air pipe is limited by many factors, and the effect is not ideal

First of all, the number of feeding points is not enough, and the amount of backburned ash is far from reaching the amount of ash required to establish a cycle; secondly, the location of the feeding point cannot really make the backburning fly ash blend into the mass transfer atmosphere in the furnace; the third point The feeding point is connected to the secondary air pipe, which seriously affects the regulation of the secondary air volume

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