Cooling gas system for cooling section of shaft furnace

Abstract

The invention belongs to the technical field of metallurgy, and in particular relates to a cooling gas system used in the cooling section of a shaft furnace. The cooling gas system includes a cooling gas intake pipeline, a cooling gas intake pipeline, a cooling and dust removal device, a pressure raising device, an intake switching valve group, a carburizing gas device, and a furnace bottom material temperature measurement device, wherein the cooling gas intake pipeline Including the intake ring pipe and multiple air inlets; the cooling air collection pipeline includes the air collection ring pipe, multiple air collection ports and multiple air collection hoods; the cooling and dust removal device is connected to the furnace outlet; the air inlet of the intake switching valve group They are respectively connected with the pressure raising device and the carburizing gas device, and the gas outlet is connected with the furnace inlet; the furnace bottom material temperature measuring device is arranged under the inlet pipeline. Therefore, the cooling air system adopts multiple air inlets, multiple air intake ports and air intake hoods evenly distributed in the ring pipe, which ensures the uniformity of air intake in the cooling section and realizes efficient recovery of cooling air, thus reducing the unused cooling air. Effective recovery and rising to the reduction section will adversely affect the reduction reaction.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to the design of a cooling gas inlet and gas collection pipeline system in the lower cooling section of a gas-based shaft furnace for directly reducing iron-containing minerals to produce sponge iron. [0002] technical background [0003] At present, the gas-based shaft furnace process accounts for more than half of the world's direct reduction ironmaking production, and is the most mature sponge iron production process. In 2015, the world's direct reduced iron production was 72.57 million tons, of which, the production of direct reduced iron by gas-based shaft furnace method accounted for about 80%. Gas-based shaft furnace direct reduction ironmaking is the most important non-blast furnace ironmaking method. Its product is direct reduced iron (also known as sponge iron), which is mainly used as raw material for electric furnace steelmaking and also as coolant for con...

AI Technical Summary

Problems solved by technology

However, there are some problems in the air intake and collection systems of large-scale experimental shaft furnaces and industrial shaft furnaces: (1) The existing air intake system adopts single-port entry or straight pipe entry, and the distribution of cooling air after entering the shaft furnace is uneven. The cooling effect is different in each area, the heat exchange effect of the cooling air is not ideal, and the utilization rate is low, while the sponge iron in the cooling section of the shaft furnace has a local high temperature; (2) The cooling air continues to go upward after exchanging heat with the sponge iron in the cooling section , due to the simple design or unreasonable layout of the gas collection pipeline system, the gas collection effect is not good, and part of the cooling gas cannot be collected effectively and continues to rise into the reduction section of the shaft furnace, which affects the iron ore reduction reaction effect; The air collection effect of the pipe has been improved, but there will be a lot of materials used in the pipe, which hinders the smooth downward movement of the furnace

In short, the current large-scale experimental shaft furnaces and industrial shaft furnaces have a certain degree of unreasonable layout of the intake and gas collection systems, using a single gas inlet, gas collection port, or single straight pipe or multiple rows of straight pipes as the intake pipe, collection pipe, etc. The air pipe is simple in design, but there are problems such as poor cooling air circulation effect and low cooling air utilization rate

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