Slag falling device and circulating fluidized-bed boiler

Abstract

The invention discloses a slag falling device and a circulating fluidized-bed boiler. The slag-falling device comprises a slag discharging pipe (1), a conveying pipe (2) and a slag feeding pipe (3), wherein an upper end port of the slag discharging pipe (1) is communicated with a slag discharging port of the boiler, and a lower end port of the slag discharging pipe (1) is communicated with an upper end port of the conveying pipe (2); and an upper end port of the slag feeding pipe (3) is communicated with a lower end port of the conveying pipe (2), and a lower end port of the slag feeding pipe (3) is communicated with a slag feeding port of a slag cooler. The slag falling device also comprises an air inducing component which is communicated with the conveying pipe (2) and can form a low-pressure zone above the conveying pipe (2). The air inducing component forms the low-pressure zone above the conveying pipe, so that the gas flow which is carried into the slag cooler by bottom slag when the bottom slag flows downwards is reduced, and a slag running phenomenon caused by lubrication and fluidization effects of gases is avoided; and at the same time, gases entering the low-pressure zone flow in a single phase, so that the wind volume and the wind speed are easy to control.

Description

technical field [0001] The invention relates to the field of boiler slagging, in particular to a slagging device and a circulating fluidized bed boiler. Background technique [0002] my country has abundant inferior fuel reserves, and circulating fluidized bed boilers have wide adaptability to coal types. The low-cost and high-efficiency utilization of inferior fuels can be realized through circulating fluidized bed boiler combustion technology. The common characteristics of low-quality fuels are low calorific value and high ash content. Therefore, circulating fluidized bed boilers burning these fuels have a large flow of fly ash and a very large flow of bottom slag. In order to control bed pressure and bed thickness, prevent slag deposition, ensure good fluidization conditions, stabilize combustion, and avoid ash and slag coking, these bottom slags must be discharged in a timely manner. On the other hand, the heat transfer, mass transfer, and combustion in the circulating ...

AI Technical Summary

Problems solved by technology

This part of the gas in the slag cooler will fluidize and lubricate the transportation of the particles, so that the particles cannot form an effective accumulation at the inlet of the slag cooler, and its flow in the slag cooler is no longer controlled by the drum. The ribs are controlled, so the drum will lose control of the slag discharge, which is the phenomenon of slag flow

When the slag flow occurs in the slag cooler, the flow rate of the bottom slag will be out of control, and a large amount of materials in the furnace will enter the slag cooler in a short period of time, which will damage the slag cooling and slag discharge devices, reduce the materials in the furnace, and lower the bed temperature. In severe cases, it may lead to shutdown

[0004] The current method of controlling slag flow is often to close the inlet opening of the slag falling device, for example, by figure 1 The opening of the valve 8 is adjusted, but this method often brings about the problem of slag blocking, and the slag discharge is easily interrupted because the pipeline opening is too small

After the occurrence of slag blockage, it is usually necessary to restore the slag discharge by manual slag removal, which will bring high labor costs, so this method is not an ideal method to solve the problem of slag flow in the slag cooler

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