Abstract
Content
- 1. The main functions of the converter lance
- 2. Possible designs of lances for afterburning CO
- 3. Bunk lance
- 4. Three-tiered lance
- 5. Future research
- List of sources
1. The main functions of the converter lance
On the converting modern lance imposed a series of often contradictory functions. The main feature is the high-performance metal scavenging does not cause emissions, ensuring an energetic function of slag formation. Applied lance should ensure vigorous flow of refining reactions in the converter bath. Thus lance parameters must have satisfactory wear resistance. Additional features modern lance is the possibility of post-combustion of CO in the working space of the converter. Today's focus is to provide the use of the lance on the ledge of the lining of the converter, to increase the resistance of the converter lining. For this purpose the lance is inflated using previously left in the converter slag. The original design is a lance having a central cylindrical-blowing hole increases post-combustion CO (Fig. 1). According to the data contained in the literature, the modernization of the structure of the central vent hole with a deterioration in the conditions of cooling of the lance tip It did not significantly affect its resistance.
2. Possible designs of lances for afterburning CO
Similar functions are performed stacked lances, as well as the first option considered, the lances are of limited use. Literature data show that at higher complexity in manufacturing the lance for industrial use have a shorter life. Applying analytical literature review and analysis of the "Internet" has allowed to allocate a resource, several designs of lances, providing a solution set of technological problems, while found that the heat balance of the converting smelting is improved by applying multilevel lances. Parameters blow holes lances and their number is optimized for a better environment of refining bath. Preliminary analysis indicated that the lances are designed with significant deviation angles between the axis of the nozzle, in such conditions, the center of the bath will fall minimum kinetic energy of the jet. For this reason, the operation of skull drawing on the lining of the converter will be little effective. The best use for this purpose is a universal tuyeres provided in obtaining efficient kinetic energy while maintaining acceptable values ??of parameters of the reaction zone Having studied the experience of the metallurgical enterprises applying such lance for blowing slag will allow them to recognize the structure is not optimal. This is indicated by the application to create a ledge separate special tuyeres. In light of this study it is relevant in the direction of improving the structure of the lance tip to the universality of its application.
3. Bunk lance
Bunk lance (Fig. 2). is different from the conventional oxygen so that a higher head nozzles for supplying oxygen into the bath, there is another row (stage) of nozzles, through which oxygen enters the space above the bath. Lower level metal for purging a result of oxidation of carbon in the zone allocated SB. The second tier of the nozzles should be within 1,65-2,5 m from the lance tip; the angle of the nozzles of the second tier to the vertical is about 30 °. The nozzles operate cylindrical and oval section; in the latter case it increases the contact area with the oxygen jets and the flow increases the degree of CO afterburning. Modern Bunk lance operate with two independent paths oxygen: oxygen consumption for post-combustion. It is known that the post-combustion of CO allows to increase the CO2 content in the exhaust gases at the neck level converter to 25 - 30%. For heat score obtained in the post-combustion carbon monoxide, the share of scrap metal smelting in the charge cooler can be increased by 3-10% At the same time with the same gas exhaust ducts can increase the intensity of blowing, the converter increasing productivity by 10 - 27%. And such a lance prevents intensive zametallivanie lance bore, and the conical portion of the neck of the converter lining.
4.Three-tiered lance
Known another type of lance - a three-tiered lance (Figure 3.) Its use will enable more effective to redistribute blown oxygen to react with the metal, slag and gas phases workspace converter, controlled foaming of slag to prevent intensive zametallivanie lance barrel, ensure a reduction of the final oxidation of the metal and slag, slag scull organize drawing on the lining of the converter prepared by blowing slag increased to 10-14% MgO. Application scull is a new feature used lances. Maximum efficiency is achieved by blowing slag decrease the angle of the blow holes in the process of the lance axis. This forces or use separate lance or to preserve the universality of improve the design of multi-functional lances.
5. Future research
Today, various companies use different designs of lances. The lance is complicated so it is difficult not so high in the manufacture of its service life, so research is ongoing and aimed at improving the lance basis from a variety of different design.
List of sources
1. Баптизманский В.И. Фурмы для продувки мартеновской ванны и их работа / В.И. Баптизманский, А.Г. Величко, А.В. Шибко // Бюл. НТИ. Черная металлургия. – 1990. – № 5 – С. 24–33.
2. Сущенко А.В. Моделирование процесса дожигания монооксида углерода в кислородном конвертере при различных вариантах подвода дутья / А.В. Сущенко, А.С. Безчерев А.С. // Вісник ПДТУ. – Вип. 14. – 2004. – С. 44–48.
3. Кислородная фурма для продувки конвертерных плавок в условиях нестабильных параметров шихты и производства / А.В. Сущенко, В.И. Ганошенко, А.Б. Ковура и др. // Труды шестого конгресса сталеплавильщиков. – М.: АО «Черметинформация», 2001. – С. 104–107.