High-temperature flue gas cleaning system

Abstract

The invention discloses a high-temperature flue gas cleaning system which is moisture condensation resistant, and tar film pasting resistant. The system comprises a filtering system, a blowback system and an ash discharging system, wherein the filtering system comprises a high-temperature flue gas connecting pipe, at least one part of a filter connected with the high-temperature flue gas connecting pipe and a fan driving the gas to be cleaned to pass through the filter, the filter is respectively connected with the blowback system and the ash discharging system, the blowback system takes protective gas as a blowback medium, and the blowback system is internally provided with a protective gas heater; and when the high-temperature flue gas cleaning system is turned on, the blowback system is taken as a filter core moisture condensation-resistant system for preheating a filter core in the filter in a blowing way, and when the high-temperature flue gas cleaning system is turned off, the blowback system is further taken as a protective gas displacement system for displacing the original gas in the filter in a blowing way. In the stage that high-temperature flue gas cleaning system is turned on, the filter core is preheated by the protective gas, so that the phenomena of moisture condensation and tar film pasting on the surface of the filter core can be avoided.

Description

technical field [0001] The invention relates to a gas purification facility, in particular to a high-temperature flue gas purification system for purifying high-temperature flue gas generated in the metallurgical industry. Background technique [0002] Pyrometallurgy often produces a large amount of high-temperature flue gas, and the treatment of these high-temperature flue gases has great significance for energy conservation and environmental protection. Taking the production of ferroalloys as an example, my country currently mainly produces ferroalloys with carbon reduction ores through submerged arc furnaces. The production varieties include ferrosilicon, silicon-calcium alloys, industrial silicon, high-carbon ferromanganese, high-iron chromium, silicon-chromium alloys, etc.; among them, Furnace material is submerged arc reduction smelting by means of resistance arc heat generated by electric arc and current passing through. During smelting, a large amount of combustible g...

AI Technical Summary

Problems solved by technology

[0004] Practice has found that there are mainly the following problems in applying the above-mentioned traditional high-temperature flue gas purification system to the treatment of ferroalloy submerged arc furnace gas: First, dew condensation and tar paste film cause filter element pollution

Condensation and tar film are the most important factors affecting high-temperature gas filtration, and they are also a technical difficulty that currently plagues the high-temperature gas filtration industry. The main reason for condensation and tar film is that the gas temperature drops during system start-up or shutdown. Below the dew point, liquid water or a small amount of tar condenses and precipitates on the surface of the filter element, thereby reducing the service life of the filter element

Second, the furnace pressure control problem of ferroalloy submerged arc furnace

Third, the online ash discharge problem of the high temperature flue gas purification system

In order to improve the service life of the fan, the fan in the high-temperature flue gas purification system is best installed at the end of the system's process flow, so that the entire high-temperature flue gas purification system will form a negative pressure to drive the flue gas movement, so that due to the external ash discharge system The air pressure is greater than the air pressure in the ash discharge system, resulting in difficulty in ash discharge

Fourth, the problem of producing tar when igniting and dispersing

When the gas treated by the high-temperature flue gas purification system still meets the recovery requirements, the gas needs to be ignited and released, and tar will be generated to pollute the environment.

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