Method and device for blowing breeze to pure oxygen smelting mobile filling bed smelting furnace

Abstract

The invention discloses a coal powder injection method and the device for a melting furnace of a pure oxygen smelting moving packed bed. The invention applies a coal injection device which comprises a water cooled tuyere, an oxygen blow pipe and a coal lance; a rotating diversion trench which improves the mixing level of the oxygen and the coal powder is designed on the head part of the coal lance for the swirling flow of the oxygen; the swirling flow ratio is 0 to 6; the outlet flow velocity is 180m / s to 300m / s; the distance between the end surface of the outlet of the coal lance and the front end of the tuyere is 20mm to 250mm; the pressure difference between the head part of the coal lance and the tail part is 0.02MPa to 0.1MPa; and the pressure of carrier gas is bigger than the sum ofthe pressure in the furnace ( the back pressure) and the pressure difference between the head part of the coal lance and the tail part. The invention applies a separating structure between the cooledtuyere and the oxygen blow pipe and the coal lance, which has convenient installation, application and replacement. As the tuyere is the water cooling, the head part of the coal lance obtains great cooling effects due to the high speed oxygen outside the coal lancer; the combustion ratio of the coal powder is high, the coal injection amount is great and the invention fills the blank of the coal lance for a melting furnace of a pure oxygen moving packed bed.

Description

technical field [0001] The invention relates to the technique of injecting coal powder in smelting, in particular to a method and a device for injecting coal powder into a moving packed bed smelting furnace for pure oxygen smelting. Background technique [0002] In order to save coke, pulverized coal injection has become an important means for modern blast furnaces to replace coke with coal and reduce product costs in recent years. European patent EP27822 introduces a three-channel blast furnace pulverized coal burner. The burner has coaxial channels separated from each other. From the inside to the outside, there are respectively a pulverized coal channel for air as a carrier gas, an oxygen-enriched channel and a channel for controlling the flame temperature. The gas channel, the burner has a large volume and weight, which brings inconvenience to the operation in front of the furnace. Due to the increase of the temperature control gas channel, its structure is complicated, ...

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Problems solved by technology

[0003] Chinese patent application numbers CN93118519.X, CN92205037.6, and CN99801352.8 disclose pulverized coal burners, which adopt separate coaxial channels to inject pulverized coal and oxygen respectively, but these oxygen-coal burners are all for blast furnace coal injection Specially designed, they are obliquely inserted into the direct blowing pipe of the blast furnace tuyere for coal injection and local oxygen enrichment for the hot air. The designed oxygen enrichment rate is lower than 30% of the total amount of hot air blasted. Moving packed bed melting furnace with pure oxygen

[0004] In the design of pure oxygen packed bed smelting furnace, because pure oxygen has no excess nitrogen compared with blowing hot air, the amount of pure oxygen blown in is reduced by more than 79% compared with the amount of air blowing, and the diameter of the tuyere and the size of the circulation area of ​​the tuyere The oxygen blown in in the cold state does not have the sensible heat of the blast furnace hot air, and the combustion efficiency of the pulverized coal will also be seriously reduced. Moreover, in order to avoid burning out the tuyeres and keep the combustion zone in the high temperature zone of the flame away from the tuyeres, the pulverized coal oxygen should reach a certain level. out speed

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