Optimal application of key technologies for converter gas dry dust collection and recovery system

The converter gas dry dust collection and recovery system has many unstable factors in operation, and failures occur from time to time, which seriously restricts the balance and stability of production. Through process and equipment improvements, optimized application of evaporative cooler spray water quality improvement, evaporative cooler barrel wall efficient cleaning technology, electrostatic precipitator explosion venting control technology, electrostatic precipitator electric field degradation control technology, and electrostatic precipitator cathode line online The replacement of key technologies such as technology gradually improved the inherent shortcomings of the original technology and effectively solved various problems. Through the optimized application of the key technology of the converter gas dry dust removal and recovery system, the stable and efficient operation of the equipment system has been realized, and its operating efficiency has reached or exceeded the best level of domestic and foreign counterparts. At the same time, the original converter gas dry dust removal and recovery technology has been obtained. An effective supplement and improvement. 1 Overview As early as 1965, the successful operation of the converter flue gas dry dust collection and recovery system in the Donawitz plant in Austria has attracted the attention of the world. In the early 1980s, Germany's Lurgi and Thyssen worked hand in hand to push the converter gas dry dust collection and recovery process to a new level. The process system is referred to as the LT system. In recent years, LT gas recovery technology has been widely used in the primary dust removal of converters at home and abroad. The technology adopted by Thyssenkluber in Germany and Linz steel mills in Austria is relatively mature; domestic Shanghai Baosteel, Shandong Laiwu Steel, Inner Mongolia Baotou Steel This technology is also used. 2 Process flow and technical principle of converter gas dry dust collection and recovery system 2.1 Process flow The process flow of converter gas dry dust collection and recovery system is shown in Figure 1. 2.2 Technical principle It is a process technology that captures, cools, purifies and recovers CO gas with a large amount of high temperature dust gas containing CO generated during the production process of the converter. Its core is dry electric dust removal. The high-temperature dust gas produced by converter smelting is cooled to about 1000℃ by the vaporization cooling system, enters the evaporative cooler of the LT system for water mist cooling and coarse dust removal, and then enters the electric dust removal for dry fine dust removal. The system is provided by an axial fan Negative pressure driving force. In the early and late stages of converter smelting, the CO concentration is low, and the bell valve is switched to the release tower for ignition and combustion; in the middle of converter smelting, the CO concentration is greater than 30%, and the bell valve is switched to the gas cooler for water spraying and cooling, and then the gas is sent to the gas The cabinet is recycled. LT converter gas recovery technology has a high degree of control and fast switching speed during gas recovery; the recovered gas has a low dust concentration and a long fan life. The electrostatic precipitator uses the strong electric field generated by the DC high-voltage power supply to ionize the gas, produce corona discharge, and then charge the suspended dust particles, and under the action of the electric field force, the suspended dust particles are separated from the gas and captured The dust removal device. The dust removal efficiency is high, the equipment resistance is small, and the total energy consumption is low. 3 Application prospects of converter gas dry dust removal and recovery technology The superiority of the LT system benefits from its dry dust removal system, there is no waste water and sludge treatment problem; the ultra-low dust concentration during gas recovery can be directly supplied to gas User use. It can be expected that the further promotion, application and continuous improvement of this process technology will definitely promote the environmental protection, emission reduction, energy saving and consumption reduction of converter dust removal. 4 Optimized application background 4.1 Significance of optimized application The converter gas dry dust removal and recovery system, due to the inherent limitations of this technology, there are many unstable factors in the operation of the system. The evaporative cooler, electrostatic precipitator, ID fan and the entire system control all have different degrees of defects, and failures occur from time to time, which seriously restricts the balance and stability of production. Optimizing and improving the application of new technologies in the system can improve system defects, control degradation trends, greatly reduce failure rates, and achieve stable system operation to ensure smooth production. 4.2 Difficulties in optimizing application There are 16 water-vapor dual-flow nozzles in the evaporative cooler, which are evenly distributed at the top air inlet of the evaporative cooler, which is prone to blockage during use, resulting in poor spray cooling effect; as the production operation cycle increases, evaporative cooling Mud scales of different thicknesses will form on the wall of the container. The accumulation of mud scale is affected by temperature changes and often falls and blocks the ash conveying system. According to the understanding of brother units in the same industry, there is no corresponding control and treatment measures, and it needs to be optimized and improved based on its own. There are frequent disconnections in the cathode wire inside the electric field of the electrostatic precipitator, which often causes the electric field to short-circuit and lose power, and there are many unplanned overhauls, which seriously affect the normal production. This kind of situation exists in all units at home and abroad, and many exchanges and discussions have been conducted with the design unit, but no better control plan has been reached. It also needs its own system analysis and innovative solutions. ID fan is an equipment imported from a foreign complete machine. After less than a year of operation, there were problems with high bearing operating temperature, large vibration, and even bearing burnout. It has been negotiated with the equipment manufacturer for many times, and no real one has been found. cause of issue. It is necessary to find real problems in combination with unit installation and system operation to improve control. 4.3 Optimization and improvement situation Through detailed research and analysis of converter gas dry dust removal and recovery technology, combined with the actual situation of system operation, actively carry out process optimization and equipment improvement, and constantly adopt new technologies, gradually improve the inherent defects of the original technology, and supplement the original technology The blanks of the converter gas dry dust collection and recovery technology have been fully developed. Through practical application, various problems have been fundamentally solved. So far, the optimized application of the converter gas dry dust removal and recovery technology has realized the stable and efficient operation of the equipment system, and has effectively promoted the recovery of the converter gas on the basis of ensuring a balanced production.