Innovation comprehensive solutions for off-gases cleaning in steel industry. Technical solutions for cleaning high-temperature gas flows

Abstract

Steelmaking in electric arc furnaces (EAF) is accompanied by formation of high-temperature gas flows, containing a number of hard particles and harmful gaseous substances. During charging and adding steel scrap into a furnace, a volley dust fall takes place, the dust being spread over large distances from the steel-works making an ecological damage to environment. Ecological and energy parameters of EAF gas-cleaning systems operation considered. It was shown, that existing EAF gas-cleaning systems, based on bag or electric filters, do not ensure residual dust concentration in the cleaned gases as 10 mg/m 3 . At that to clean gases, it is necessary to cool them preliminary, which results in irrevocable loss in the flow heat potential. A technical solution was proposed to modernize the EAF gas-cleaning systems, based on splitting unorganized and organized gas emissions: the first gas-cleaning system intends for cleaning unorganized emissions, and the other – for cleaning organized high-temperature emissions. It was proposed to subject the organized emissions – high-temperature gas flows – to comprehensive cleaning of dust, CO, NO x , SO 2 , dioxines and dibenzofurans PCDP/PCDF, benzpyrene in ceramic filters with high heat utilization and steam generation. Description of ceramic filters presented, mass production of them was organized at NTZ “Bakor”. The filters ensure the residual concentration of hard particles at the exit less 2 mg/m 3 and provide the catalytical afterburning of CO, PCDP/PCDF and benzpyrene. Technical parameters of a pilot facility comprising ceramic pulse filter ФКИ-9,8, designed for cleaning 1000 m 3 /h of a gas flow having temperature up to 600 °С presented. The facility can be connected to existing gas-cleaning system with online data transfer from numerous sensors via internet. The comprised laser dust meter ensures monitoring in real-time mode the residual concentration of hard particles at the exit of the facility.