At present, the environmental protection pressure of the rotating furnace steelmaking plant is huge. Among them, the dust removal system of the rotating furnace flue gas is the top priority, and it is necessary to implement a clean transformation to achieve ultra-low emissions. Therefore, the selection and application of efficient, safe and low-consumption rotating furnace dedusting technology has become an urgent topic for iron and steel enterprises.
The wet method and dry method of rotating furnace flue gas dedusting have their own advantages
Rotating furnace wet dedusting technology is abbreviated as OG. OG is the abbreviation of Oxygen rotating furnace Gas Recovery in English, which means oxygen rotating furnace gas recovery. The rotating furnace using OG technology produces a large amount of high-temperature and high-concentration CO flue gas in the furnace due to the violent oxidation reaction during blowing. The flue gas suppresses the intrusion of surrounding air through the lifting of the skirt and the control of the flue gas pressure inside the hood. In the case of unburned, the technology adopts the vaporization cooling flue to cool the flue gas, and after being purified by the two-stage Venturi tube dust collector, it enters the gas recovery and release system.
Rotating furnace dry dust removal technology is abbreviated as LT. The LT method was jointly developed by Lurgi and Thyssen in Germany. LT is the abbreviation of the names of the two companies. This technology uses vaporization cooler to cool flue gas, and after being purified by cylindrical dry electrostatic precipitator, it enters the gas recovery and release system. This law began to be used in gas recovery projects in 1981.
Rotating furnace dry dedusting technology has a large one-time investment, complex structure, many consumables, and high technical difficulty. The market promotion rate in my country is less than 20%. Moreover, the dry dust removal technology uses a huge dry electrostatic precipitator to remove the viscous primary rotating furnace dust. The dust collector is easy to accumulate dust and the dust discharge is unstable.
Compared with the dry dust removal process, the OG wet dust removal process has simple structure, low cost, and high purification efficiency, but it has disadvantages such as high energy consumption, large water consumption, complicated sewage treatment, and high operating costs. Moreover, the wet dust removal technology washes all the dust into the water regardless of particle size, resulting in a large amount of dust removal sewage. Although the technical level of dry and wet dedusting processes has been continuously improved in the process of localization, their respective inherent defects have not been resolved.
In response to the above situation, industry experts have proposed semi-dry dust removal technology in recent years, which has been promoted in China. At present, the number of rotating furnaces using semi-dry dedusting technology exceeds the number of rotating furnaces using dry dedusting technology. The semi-dry dedusting process uses a dry evaporative cooler to recover 20%-25% of dry ash, which retains the advantages of wet dedusting and overcomes the defects of dry and wet dedusting technologies. In particular, this technology can transform the wet dedusting process without having to completely dismantle and redo it like the dry dedusting process, so that the original facilities can be retained to the greatest extent and investment costs can be saved.
Post time: Sep-11-2023