The Researches On End-point Control System Of Converter Smelting

A large number of meaningful and effective work have been done on end-point control technology of converter by experts in domestic and foreign steel industry. Because of constraints,now in the most of the small converter, the workers control the smelting and tapping still resorting to experience.Because there is great difficulty either from the capital or from the device as installing sublance for small converter.As the static model of basic oxygen furnace is the basis of dynamic model of basic oxygen furnace, and the end-point hit rate of static model influences the end-point hit rate of dynamic model.So researches of improving the end-point hit rate of static controlling model of basic oxygen furnace still have important significance.In this paper the development history of the end-point controlling technology on the converter is generalized.Based on material and heat equilibrium of various physics-chemistry reactions and practical experience parameter about steel-smelting, the theoretical model of LD converter is established.And the date base of expert system are established by collecting and analysing the data generated in smelting process.The application software on end-point controlling of converter is exploited by Visual Basic 6.0, and system background database used Microsoft Access.The software can achieve the following tasks:(1)The theoretical model:inputting the data needed for smelting,software can fast calculate oxygen consumption, lime requirement, scrap steel requirement, coolant requirement and other parameter by related formula.This software can save the computing time, improve efficiency, and it can be used in project design of related courses.(2) The expert system:the expert system is established based on the problem-solving ability of smelting expert.Through inputting the temperature,component and requirement of hot metal and the component of other raw materials, oxygen pressure, oxygen flow, oxygen supply time, lance height controlling, lime requirements and addition time in different batches, ore requirement, scrap steel requirement and other parameter can be gived.This system depends on the principle of“Reproduction”.(3) Data query and update system:users can query data by inputting steel grade or date from data base which are established by collecting large amounts of data.When the data base can not meet the user’s requirement, the data can be added or updated by manual inputting.The data base system achieves an data management which is effective, convenient and practical.Through feasibility analysis on the expert system of converter smelting, it has been found that the expert system has high accuracy in the forecasting of lime requirement, coolant requirement,oxygen supply time and lance hight controlling.For the following reasons:one-time investment of the sublance system is too large; the maintenance costs of the sublance system are too high;the bulk of the sublance system is too large, most small converters do not have sublance or can not install sublance, the end-point controlling system of converter smelting has solved the problems.It has significance in the areas of improving the hit rate of tapping temperature and carbon content,reducing consumption, improving the quality of steel, shortening the refining cycle, improving production efficiency.And for the static model of basic oxygen furnace is the basis of dynamic model of basic oxygen furnace, so the researches of static controlling model of basic oxygen furnace can service dynamic model.