Process and device for recycling flue gas afterheat of electric furnace

Abstract

The invention provides a process for recycling flue gas afterheat of an electric furnace. The process comprises the following steps: firstly passing high-temperature flue gas generated by the electric furnace through a flue gas hood and an evaporative cooling flue so as to enter into a burning settling chamber, introducing the discharged flue gas into a heat accumulating type rapid cooling device, changing the working conditions of two heat accumulating units (A and B) of the heat accumulating type rapid cooling device periodically, introducing the flue gas into a bag-type dust collector for dedusting, and then discharging the processed flue gas into the atmosphere through a draft fan and a chimney. The invention provides a device for recycling flue gas afterheat of the electric furnace. The device mainly comprises the hood, a flue, the burning settling chamber, a flue gas inlet, a flue gas outlet, a circulating inlet, a circulating air outlet, a circulating fan, a convection type afterheat boiler, the bag-type dust collector, the draft fan and the chimney, and is characterized in that the heat accumulating type rapid cooling device is installed on the back of the burning settling chamber, mainly consists of a heat transfer unit A and a heat transfer unit B which are provided with honeycomb ceramic heat accumulators, and has two operating modes. The process and device for recycling the flue gas afterheat of the electric furnace have the advantages of realizing full recovery of low-temperature flue gas afterheat, simultaneously avoiding the new synthesis of dioxin, and realizing the standard flue gas emission.

Description

Technical field: [0001] The invention relates to the technical field of iron and steel metallurgy, in particular to an electric furnace flue gas waste heat recovery and utilization process and equipment in steelmaking production. Background technique: [0002] The existing waste heat utilization method of electric furnace flue gas is that the high temperature flue gas generated by the electric furnace enters the water-cooled flue through the exhaust hood, and the temperature is reduced to 350°C after being sprayed and cooled by the combustion settling chamber and the water-cooled flue, and then combined with the secondary flue gas After mixing, it enters the bag filter, and the purified flue gas is discharged into the atmosphere through the exhaust fan and chimney. This method of utilizing waste heat from electric furnace flue gas has the following defects: 1. Water cooling method is adopted, and the amount of cooling water is large, which consumes a large amount of electric...

AI Technical Summary

Problems solved by technology

This method of utilizing waste heat from electric furnace flue gas has the following defects: 1. Water cooling method is adopted, and the amount of cooling water is large, which consumes a large amount of electric energy; 2. The method of spray cooling is adopted, and the cooling speed is fast. The problem of evil, but it causes a lot of waste heat to be unusable. At the same time, it increases the flow of flue gas and increases the power consumption of the exhaust fan.

However, due to the re-synthesis of dioxins at a temperature of 700°C, the use of a slow convection waste heat boiler to recover waste heat will inevitably lead to excessive emissions of dioxins from electric furnace flue gas

At present, there is no waste heat recovery process and equipment that can effectively avoid the re-synthesis of dioxin while fully recovering the waste heat of electric furnace flue gas

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