Optimal application of key technologies in converter gas dry dust removal and recovery system

There are many unstable factors in the operation of the converter gas dry dust removal and recovery system, and failures occur from time to time, which seriously restricts the balance and stability of production. Through process and equipment improvement, optimize the application of evaporative cooler spray water quality improvement, evaporative cooler bucket wall high-efficiency cleaning technology, electrostatic precipitator explosion vent control technology, electrostatic precipitator electric field deterioration control technology, electrostatic precipitator cathode line online Replace key technologies such as technology, gradually improve the inherent defects of the original technology, and effectively solve various problems. Through the optimized application of the key technologies 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 even 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 removal and recovery system in the Donawitz plant in Austria has been concerned by the world. In the early 1980s, German Lurgi and Thyssen worked together to push the converter gas dry dust removal and recovery process to a new height, the process system referred to as LT system. In recent years, the LT gas recovery technology has been widely used in the primary dust removal of converters at home and abroad. The technology adopted by Thyssenkruber in Germany and Linz in Austria is relatively mature; domestic Baosteel in Shanghai, Laigang in Shandong, Baosteel in Inner Mongolia This technology is also used. 2 The process flow and technical principle of the converter gas dry dust removal and recovery system 2.1 Process flow The process flow of the converter gas dry dust removal 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 in the production process of the converter. The core is dry electrostatic precipitator. The high-temperature dust generated by converter smelting is cooled to about 1000°C 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 electrostatic precipitator for dry fine dust removal. The system is provided by an axial flow fan. Negative pressure driving force. In the early and late stages of converter smelting, when the CO concentration is low, the bell valve is switched to the release tower for ignition and combustion; in the middle stage of converter smelting, when the CO concentration is greater than 30%, the bell valve is switched into the gas cooler for water spray cooling and then sent to the gas Cabinets are recycled. LT converter gas recovery technology has a high degree of control and fast switching speed during gas recovery; the recovered gas has low dust concentration and long fan life. The electrostatic precipitator uses the strong electric field generated by the DC high voltage power supply to ionize the gas and generate corona discharge, thereby charging the suspended dust particles, and under the action of the electric field force, the suspended dust particles are separated from the gas and captured. 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 is due to the fact that it is a dry dust removal system, and there is no problem of waste water and sludge treatment; 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 Background of optimized application 4.1 Significance of optimized application In 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. Evaporative coolers, electrostatic precipitators, ID fans and the control of the entire system have various 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 the deterioration trend, greatly reduce the failure rate, and realize the stable operation of the system 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 air inlet at the top of the evaporative cooler, which is prone to blockage during use, resulting in poor spray cooling effect; with the increase of production operation cycle, evaporative cooling Sludge of different thicknesses will form on the wall of the barrel, and the accumulation of sludge is affected by temperature changes, and it often falls and blocks the ash conveying system. According to the understanding of the brothers in the same industry, there is no corresponding control measures, and it needs to be optimized and improved based on its own. The cathode line inside the electric field of the electrostatic precipitator is frequently disconnected, which often causes the electric field to be short-circuited and lose power, and the number of unplanned maintenance is frequent, which seriously affects the normal production. This kind of situation exists in all units at home and abroad. After many exchanges and discussions with the design unit, no better control plan has been obtained. It also needs its own system analysis and innovative solutions.