Efficient long-service-life single-runner secondary combustion oxygen lance and using method

Abstract

The invention discloses an efficient long-service-life single-runner secondary combustion oxygen lance which comprises a lance body and a lance head. The gun body comprises an outer pipe, a middle pipe and a central pipe, and the gun head comprises a gun head end part and a water diversion disc; a circle of main blowing holes and a circle of auxiliary blowing holes are uniformly formed in the end part of the gun head in the circumferential direction; the lowest points of the outlet outer edges of all the main blowing holes are located on the bottom edge of the main hole conical surface, the highest points of the outlet outer edges of all the auxiliary blowing holes are located on the top edge of the main hole conical surface, the lowest points of the outlet outer edges of all the auxiliary blowing holes are located on the bottom edge of the auxiliary hole conical surface, and the highest points of the outlet outer edges of all the auxiliary blowing holes are located on the top edge of the auxiliary hole conical surface. By optimizing the distribution of the blowing main holes, the interference effect of main and auxiliary jets is reduced, secondary combustion in the converter is promoted, the converter blowing metallurgical effect is improved, and by cooling and strengthening the lance head, inhibiting ablation of the lance head of the oxygen lance and prolonging the service life of the oxygen lance, the comprehensive effects of increasing the steel scrap ratio of the converter, shortening the smelting period of the converter, improving the quality of molten steel and the like are achieved.

Description

technical field [0001] The invention belongs to the technical field of converter steelmaking, and in particular relates to a high-efficiency and long-life single-flow secondary combustion oxygen lance and a use method. Background technique [0002] Converter steelmaking is the main process of molten steel smelting in my country, accounting for more than 80% of my country's steel production. All are vigorously improving the scrap ratio of converters. However, with the increase of the scrap ratio of the converter, the heat of the molten pool is obviously insufficient, which cannot meet the requirements of the molten steel temperature at the smelting end point. In order to overcome the problem of insufficient heat in converter smelting under the condition of large scrap ratio, scrap preheating is usually used in large-scale production, and heating supplements (coke, SiC, ferrosilicon, etc.) are added to the converter, but the above two types of technologies have shortcomings. ...

AI Technical Summary

Problems solved by technology

[0007] Chinese patent "Wu Wei, Hu Yanbin, Tong Puqiao, etc., a dual-stream oxygen lance and its use method, authorized announcement number CN106282481 B", through the analysis of conventional secondary combustion oxygen lance technology, pointed out the shortcomings of the existing technology , mainly as follows: (1) the auxiliary oxygen hole channel occupies a large water cooling space of the nozzle, which reduces the service life of the nozzle; (2) due to the limitation of the cooling space in the inner cavity of the nozzle, the increase in the number of outlets of the auxiliary hole is restricted, which affects the The effect of secondary combustion is brought into play; (3) secondary combustion produces a large amount of CO 2 , which reduces the concentration of converter gas and affects the recovery of converter gas; (4) secondary combustion oxygen lances, especially double-channel oxygen lances, the auxiliary holes occupy more flow, resulting in poor converter slag splashing effect

[0008] Chinese patent "Zheng Shuguo, Liu Zhiyuan, An Yanfei, etc., a single-channel secondary combustion oxygen lance and its use method for increasing the scrap ratio of converters, application publication number CN 108977620A", aimed at the auxiliary hole flow rate of less than 15% and Due to the limited heat supplement effect of the secondary combustion and the fact that the number of outlets of auxiliary holes is greater than the number of inlets, it is very difficult to cool the design, and the actual production adaptability is poor. An oxygen lance nozzle end surface is provided with a main oxygen nozzle hole, and the nozzle side A secondary combustion oxygen lance with auxiliary oxygen injection holes on the wall, wherein the flow rate of the auxiliary oxygen injection holes accounts for 15-30% of the total oxygen supply flow rate, and the flow rate of the main oxygen injection hole accounts for 70-85% of the total oxygen supply flow rate

However, in industrial experiments, there are problems such as ablation and water leakage of the gun head below the auxiliary oxygen injection hole, and short life of the oxygen gun.

[0009] The Chinese patent "Chen Hongzhi, A Spin-type Secondary Combustion Oxygen Lance and Its Application, Application Publication No. CN105154617A", aimed at the shortcomings of conventional secondary combustion oxygen lances, such as low localized combustion efficiency and severe radial jet furnace lining scour, discloses A secondary combustion oxygen lance provided with a plurality of secondary oxygen hole structures in the circumferential direction of the gun body; wherein, the secondary oxygen holes penetrate the outer tube of the gun body and the middle water riser and are tangent to the oxygen tube of the oxygen lance, and the secondary oxygen holes The angle α between the axis and the axis of the oxygen lance body is 30°~60°; the number of secondary oxygen holes is 3~5, the hole diameter is 3~7mm, and the distance from the main oxygen nozzle is 400~1600mm

However, its complex secondary oxygen pore structure increases the difficulty of the processing and production of the oxygen lance, and no actual production and application reports have been seen so far.

[0010] To sum up, it can be seen that in terms of single-channel secondary combustion oxygen lance technology, domestic and foreign scholars have successively carried out a lot of research on the improvement of secondary combustion efficiency, flow distribution of main and auxiliary oxygen injection holes, structure of lance head and control method of oxygen lance. and formed a series of patented technologies. Some technologies have achieved good heat supplement and temperature rise effects in industrial tests, but failed in terms of the optimal distribution of the flow rate of the main and auxiliary oxygen injection holes, and the structure and arrangement of the auxiliary injection holes. Reached a consensus, there are few studies on the damage mechanism of the secondary combustion oxygen lance, the service life of the oxygen lance, the efficient heat transfer of the secondary combustion, and the jet flow interference of the main and auxiliary nozzles.

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