① Sintering raw materials: loading and unloading, crushing, screening and storage and transportation: generating dusty gas;
(2) mixing system: generating steam-dust waste gas;
③ Mixed sintering system: high-temperature waste gas of dust, flue gas, SO2 and nitrogen oxides;
(4) Dust-bearing waste gas is produced in the process of crushing, screening, cooling, storage and transportation of sinter.
The amount of waste gas produced by sintering plant is large, the concentration of dust and SO2 is high, and the pollution is serious.
Every link has dust removal, and the typical dust removal system in sintering plant includes:
(1) head: general electrostatic precipitator, the flue gas comes from high-temperature sintering waste gas;
(2) The tail of the aircraft is generally dusted by a bag or electrostatic precipitator, and part of the waste gas is sintered, and the waste gas generated by sintering, crushing, screening, cooling, storage, transportation and transshipment is sintered;
(3) In batching workshops, raw material storage yards and other places, cloth bags are generally used to collect dust, and the collected dust is returned to the silo for reuse.
Sintering machine head: electrostatic dust removal is generally used.
(1) The flue gas emission is large, and the dust emission concentration is generally low, about 1~6g/m3, which depends on the sintering process.
(2) The flue gas temperature fluctuates greatly, generally 80℃ ~ 200℃;
(3) The moisture content of flue gas is large, generally around 10%, and the dew point temperature of flue gas is high;
(4) The content of calcium, potassium and sodium in dust is high. Because of the low boiling point of alkali metal compounds, they volatilize into the flue gas after passing through the electrostatic precipitator at the sintering machine head and are enriched in the dust, which increases the specific resistance of submicron dust particles, and at the same time, their specific gravity is small, which is not conducive to dust removal;
(5) The particle size of dust is small, with dust particles smaller than 5 microns accounting for more than 30%;
(6) The specific resistance of dust is about109 ~10/2 Ω. Cm, which belongs to medium-high specific resistance dust;
(7) The negative pressure of flue gas is large, about 20KPa, which is easy to leak air and corona seal.
B Sintering machine tail: generally, electric dust removal or bag dust removal is adopted, and the market ratio is about 1: 1.
(1) The dust emission is small, accounting for about 25%~50% of the nose dust emission, but the dust concentration is large, accounting for about15 ~ 20g/m3;
(2) The average flue gas temperature is 80℃~ 150℃, and the flue gas moisture is normal;
(3) The dust has high viscosity, and the content of Fe2O3 and FeO is above 50%, so it has high recycling value;
(4) The dust is coarse, with an average particle size of about 40μ m;
The dust resistance is about1010 Ω cm, and the negative pressure is normal.