Spray gun used for desulphurizing by directly spraying and blowing magnesium desulfurizing agent to molten iron

Abstract

The invention discloses a spray gun used for desulphurizing by directly spraying and blowing a magnesium desulfurizing agent to molten iron. The spray gun is composed of a connecting section, a gun body section and a spraying-blowing section. The connecting section is sequentially composed of a connecting flange and a compound gun core. The outer wall of the gun body section and the outer wall of the spraying-blowing section are made of fire resistant materials in a lining pouring manner to form a gun wall. The spraying-blowing section comprises a spraying-blowing section gun body and a special-shaped gun head arranged at the top end of the spraying-blowing section gun body. The compound gun core sequentially comprises an inner inserting pipe, a main pipe and a reinforcement pipe from inside to outside. The main pipe is inserted into an inner inserting pipe connector. The inner inserting pipe penetrates the inner inserting pipe connector and is inserted into the end of a vertical channel. A graphite spraying-blowing pipe is installed in a radial horizontal channel, extends outwards and is installed in a graphite spraying-blowing pipe installing hole in the gun wall. By means of the spray gun, smoothness of a spraying-blowing flowing channel of the spray gun is guaranteed, the comprehensive using performance of the spray gun is greatly improved, and the comprehensive aims that the service life of the spray gun is prolonged, the maintenance cost of the spray gun and the consumption of the desulfurizing agent are reduced, and the desulphurization production working rate is increased are achieved.

Description

technical field [0001] The invention relates to the field of molten iron pretreatment, in particular to a desulfurization spray gun for direct injection of magnesium desulfurizer into molten iron. Background technique [0002] The document "External desulfurization of molten iron, Shanxi Metallurgy, 2007, No1" reported that molten iron is the basic raw material for molten steel smelting, and its chemical composition and physical properties determine the quality of steel products and the benefits of enterprises to some extent. Therefore, Since the 1970s, people began to pay attention to the development of molten iron pretreatment technology, and continuously improved its technology and methods to remove harmful elements in molten iron. In addition to sulfur-containing steel, sulfur is one of the main harmful elements in steel, but in the process of blast furnace ironmaking, it is necessary to increase the alkalinity of slag and furnace temperature, which will reduce the techn...

AI Technical Summary

Problems solved by technology

Due to the low gasification temperature and poor fluidity of metal particles magnesium, it is easy to mix with the injection carrier gas N 2 Reaction and other characteristics, in actual production, the nozzle of the inverted Y-shaped double-nozzle spray gun often becomes clogged, and it is difficult to unclog the site. The normal use performance of the spray gun is affected, and the consumption cost of the spray gun rises sharply. At the same time, although lime is compounded in the desulfurizer, the consumption of metal magnesium does not decrease, and is even higher than that of pure magnesium sprayed with metal particles.

[0007] Based on the above, it can be seen that for the direct injection molten iron desulfurization process of magnesium desulfurizer (pure metal magnesium or metal magnesium + lime), due to the inherent characteristics of metal magnesium, it is easy to cause nozzle blockage. Therefore, the spray guns used in the early stage are all single nozzles Straight-through spray gun, through the straight-line equal-diameter flow channel of the spray gun, reduces the spray flow resistance of the spray gun, ensures the stability of the spray flow, and avoids nozzle clogging; although the inverted Y-shaped double-nozzle spray gun obviously improves the concentration of magnesium desulfurizer in molten iron. Dispersion status and desulfurization reaction kinetics conditions, but the problem of nozzle clogging often occurs

According to the analysis, for the inverted Y-shaped double-nozzle spray gun, compared with the original single-nozzle straight-through spray gun, due to the sudden change in the local structure of the injection channel, the stability and uniformity of the flow field in the injection channel are destroyed, and the jet flow field of the two nozzles is easy to Differences occur, especially for spray guns with low nozzle processing accuracy, the difference in the jet flow field of the two nozzles is caused by the difference in the processing of the nozzle flow channel; The difference will inevitably lead to the difference of slag accumulation in the flow channels of the two nozzles; during the desulfurization process of molten iron injection, due to the violent fluctuation of the liquid level of molten iron and the static pressure of the nozzle, the molten iron at the nozzle with small injection kinetic energy will be recharged. When the injection pressure of the injection system and the feeding speed of the desulfurizer fluctuate greatly, the static pressure of the molten iron will cause the molten iron to recharge at the two nozzles at the same time, forming a blocked iron gun; due to the inverted Y-shaped injection channel structure, the nozzle flow channel It is long and can only dredge between a single nozzle and the main channel of the spray gun. The dredging process is very difficult, and it is also difficult to ensure the consistency of the dredging of the two nozzle channels. This increases the hidden danger of the spray gun continuing to be blocked after dredging. In addition, compared with the desulfurization of the gasification chamber spray gun purely spraying metal particle magnesium, the nozzle of the spray gun directly sprays metal particle magnesium or metal magnesium and lime desulfurizer combined injection of molten iron desulfurization. Magnesium consumption is relatively high. How to promote the penetration of magnesium bubbles of metal particles injected by magnesium desulfurizer, shorten the heating and gasification time of metal magnesium in molten iron, and strengthen the dissolution process of magnesium steam in molten iron are the key factors to improve the utilization rate of magnesium metal desulfurization. The key point is also the development direction of continuous improvement of magnesium desulfurization agent injection molten iron desulfurization

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