Coal powder ignition device and method

Abstract

The invention relates to the device used electric arc to ignite coal dust and its igniting method. It includes coal dust transport pipeline, anode and its cooling system, short circuit arcing mechanism, cathode, and electric arc plasma generator. The cathode is set on the axes of the coal dust transport pipeline. And the distance between the cathode front end and anode back is smaller than 500mm. The speed of the coal dust and air mixture is 10-100m per second. And its excess air ratio is from 0.1 to 1.2. It has the advantages of low energy consumption, high reliability and stability, and high igniting efficiency.

Description

technical field [0001] The invention relates to a device for igniting pulverized coal by electric arc and a related igniting method. Background technique [0002] Combustion of pulverized coal in air requires a certain high temperature environment. Large-scale industrial boilers and industrial kilns are preheated to a certain temperature before injecting coal powder for stable combustion. Early large-scale industrial pulverized coal boilers mostly used muffle furnace torch technology for ignition. Due to complex operation, heavy maintenance workload, and long start-up time, oil-fired torches were gradually replaced. Since the ignition and stable combustion of large industrial pulverized coal boilers need to consume a large amount of fuel oil, under the condition of tight oil resources and rising oil prices, research on new pulverized coal ignition technology and pulverized coal torches to replace oil torches or other gas fuel torches , It has good economic benefits for sav...

AI Technical Summary

Problems solved by technology

That is to say, the temperature of the plasma jet tail flame and the density of active particles have dropped a lot, which will inevitably reduce the ability to ignite pulverized coal, which not only reduces the reliability of pulverized coal combustion, but also increases the consumption of ignition energy

[0005] In the pulverized coal igniter disclosed by USP4228747 of Smirlock Martin E. et al., USP4221174 of Smith Doland A. et al. and USP4241673, the method of electric spark discharge is adopted to ignite the pulverized coal, and the electric arc of its discharge can expand to the pulverized coal area, The ignition efficiency is improved, but because the pulse discharge method is used, the reliability and stability of pulverized coal ignition and pulverized coal combustion are affected.

[0006] Considering that the plasma arc discharge process in the arc channel in the plasma torch body is relatively complicated and the stability is poor, so far, there has been no report on igniting and burning coal powder directly in the arc channel in the plasma torch body

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