Design And Application Of Hot Metal Pretreatment System Based On Siemens PLC

The research firstly reviews the development of hot metal pretreatment, andthen illustrates the design of this research and its application. It mainly deals withhow to achieve decentralized control and centralized management, based on SiemensPLC auto-moderation frame, between the devices involved in the process of KRdesulfurization.Hot Metal Pretreatment, as an important process before smelting steel, is usedto reduce the sulfur content in hot metal so as to molten steel with high-quality andlow-sulfur hot metal. By analyzing the desulfurization process, this research alsogives suggestion for steel works as to which technique to adopt according todifferent conditions in an aim to cut down desulfurization cost. KR process methodremoves sulfur by putting a refractory desulfurizer into the ladle, whirling andstirring, thus making a swirl so that the weighed desulfurizer can be added to thesurface of molten iron, then be involved in by the whirlpool, and be mixed with thehot metal and react with it. It is significant because it reduces smelting costs,shortens the refining cycle, extends furnace life, and improves the quality of thevarious steel.The design of this system ranges from hanging the ladle onto the molten irondesulfurization dedicated tanker, to hanging it off the tanker at the end of thedesulfurization, involving the design of all the equipment and its subsidiary controlsystem including the electrical control, signaling, interlocking, instrument andcomputer tracking pertinent to the lubricating, hydraulic and other equipment in theentire desulfurization station. Firstly it gives an introduction to the data collection ofmajor variants of the process; then expounds on the control of the major loop and ofthe operation of each device; then analyzes the collected data of relevant equipment;finally accomplishes the adjustment of the hot metal pretreatment system.The system can be divided into PC section and lower machine part based onSiemens PLCstep7programming Environment and wincc configuration screen, withthe PLC as the lower machine part, and wincc configuration software as the PCsection. It is a distributed SCADA (Supervisory Control and Data Acquisition) system featuring decentralized control and centralized management, which canachieve a better hot metal pretreatment function. It can be operated automatically,semi-automatically, manually and locally. Integration of electrical and instrumentcontrol, based on Siemens PLC, has the advantages of complete constitution, highreliability, convenience and simple maintenance. The second level computer systemin the desulfurization adopts Chinese version Oracle database server and client tool,the programming language of which is Microsoft Visual C#. The system can serve totrack second level station logistics information of KR, issue corresponding plans bythird level system, track processing data, monitor the whole process in real time andso on. The system improves processing and management and is convenient inoperation.In accordance with the technology characteristics of hot metal desulfurization,the design in this research is conducted on the basis of the principles of beingadvanced, practical, economical, and reliable, which is guaranteed thanks to thedevelopment of modern controlling devices, such as computer, transmission andinstrument.