Gas heating system for high-temperature gas injection of hydrogen-carbon-rich circulating blast furnace

Abstract

The invention discloses a gas heating system for high-temperature gas injection of a hydrogen-carbon-rich circulating blast furnace, which is characterized in that the top of the hydrogen-carbon-rich circulating blast furnace is sequentially connected with a wet dust removal and dehydration decompression system and a hydrogen-rich furnace gas decarbonization device through pipelines, and hydrogen-rich furnace decarbonization gas, European smelting furnace decarbonization gas and coke oven gas are mixed in a mixing device; the mixing volume is 10-23% of the introduction volume of the hydrogen-carbon-rich circulating blast furnace high-temperature upgrading coal gas, the mixed coal gas is divided into three paths to respectively enter three groups of electric heaters for heating, and meanwhile, the entered coal gas is subjected to flow regulation or accident cut-off through a coal gas inlet quick switching device and a flow regulation device of the electric heaters; after the coal gas heated by the first group of electric heaters is uniformly mixed with cold coal gas to reach 950 DEG C, spraying the mixture into the furnace body; and after the coal gas heated by the second group of electric heaters and the third group of electric heaters is uniformly mixed with the cold coal gas to reach 1100 DEG C, the coal gas and the cold coal gas are subjected to pressure stabilizing and buffering through the tuyere coal gas pressure stabilizing buffer and then are sprayed into the hearth through a composite tuyere of the tuyere.

Description

technical field [0001] The invention relates to a gas heating system for injecting high-temperature gas into a hydrogen-rich carbon circulation blast furnace, which is suitable for blast furnace and non-blast furnace smelting reduction ironmaking process fields. Background technique [0002] In the traditional blast furnace ironmaking process, the main fuels are coke and coal powder. Iron-containing charge and coke are loaded from the top of the furnace, and high-temperature oxygen-enriched hot air and coal powder are injected from the tuyere of the furnace hearth. The traditional blast furnace ironmaking process needs to use a large amount of fossil fuel coke and coal powder. Coke plays the role of skeleton, exothermic agent, and reducing agent in the furnace. The high-temperature blast of the traditional blast furnace brings in a large amount of high-temperature inert gas N2, making the furnace gas The proportion of CO is less than 40%, and the degree of indirect reduction...

AI Technical Summary

Problems solved by technology

The traditional blast furnace ironmaking process needs to use a large amount of fossil fuel coke and coal powder. Coke plays the role of skeleton, exothermic agent, and reducing agent in the furnace. The high-temperature blast of the traditional blast furnace brings in a large amount of high-temperature inert gas N2, making the furnace gas The proportion of CO is less than 40%, and the degree of indirect reduction of iron ore in the furnace is relatively low. Therefore, a large amount of FeO enters the hearth of the blast furnace and is directly reduced with coke in the high temperature area, resulting in a large consumption of coke; traditional blast furnaces need to use The hot blast stove consumes a lot of gas to heat the air, resulting in high energy consumption of the hot blast stove and a further increase in CO2 emissions

Oxygen-enriched blast increases the theoretical combustion temperature in front of the tuyere, which can further increase the amount of injected fuel. If the injected coal powder exceeds the limit, the unburned coal powder will increase, which will easily cause the hearth to accumulate and the furnace condition to deteriorate. At the same time, due to high oxygen-enriched smelting (over 5% oxygen enrichment rate), the amount of gas flowing to the upper part of the blast furnace has been greatly reduced compared with before, so the heat brought into the upper part of the blast furnace has been greatly reduced, which has caused the problem of the upper and lower heat of the blast furnace, thus Affects the distribution of the overall reasonable temperature field of the blast furnace, which can easily lead to abnormal furnace conditions, resulting in major vicious blast furnace production accidents such as material suspension, furnace cooling, and even hearth freezing

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