Explosion-proof method for milling high-volatile coal by coal mill

Abstract

The invention provides an explosion-proof method for milling high-volatile coal by a coal mill. The explosion-proof method comprises the following steps of: S1, adding Indonesia coal in a coal bin, controlling the outlet temperature of the coal mill to be 70 + / -2 DEG C, and ensuring that the temperature exceeds 75 DEG C for not more than 5 minutes; S2, in order to prevent the low-load primary air speed from being low, ensuring that the sum of the opening degrees of cold and hot air control valves is not less than 90%; S3, keeping high coal feeding quantity operation, and preventing coal quantity from being lower than 45t / h for long time (controlled to be less than 15 minutes); S4, checking an adjustable shrinkage cavity, an upper expansion joint and the like of a pulverized coal pipe at an outlet of the coal mill per shift, and informing maintenance treatment and merging into shortage in time when powder leakage is found; S5, for the coal mill operating for more than 8000 hours, avoiding adding the Indonesia coal in the coal bin as much as possible; if the Indonesia coal is added in the coal bin, stopping and purging once for 30 minutes every day according to the load condition; and if the Indonesia coal is added in the coal bin, stopping once according to the load condition for purging for 30 minutes during 2, 4 and 6 white shifts per week. According to the coal mill, the combustion safety of the Indonesia coal with low heat value, high moisture and high volatile matter is improved.

Description

technical field [0001] The invention relates to the technical field of coal pulverizers, in particular to an explosion-proof method for grinding high-volatile coal by a coal pulverizer. Background technique [0002] The power plant coal mill is the main equipment of the coal powder preparation system of the thermal power station. Coal mill refers to a coal mill with a working speed of 50-300r / min, which belongs to the professional equipment for preparation and processing of auxiliary materials for blast furnace ironmaking. The medium-speed coal mill can provide suitable auxiliary materials for the blast furnace ironmaking system-coal powder, medium-speed mill The coal machine is the most important large-scale equipment in the coal-to-oil pulverization system. Its operation safety and economy are extremely important to the normal operation of the coal-to-oil system. The medium-speed coal mill is suitable for grinding bituminous coal and lean coal, etc. The pulverization and ...

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Problems solved by technology

[0003] In order to reduce fuel costs, improve quality and efficiency, and adapt to changes in the fuel market, Huaneng Yuhuan Power Plant will purchase low-calorific value, high-moisture Indonesian coal as economic coal. According to the experience of burning Indonesian coal, low-calorific value, high-moisture Indonesian coal Coal quality parameters: calorific value is less than 4500kcal / kg, moisture is greater than 26%, volatile matter is greater than 33%, sulfur content is less than 0.4%. Powder accumulation, causing abnormalities in the pulverizing system, and even deflagration of the pulverizing system

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