Sintering smoke wet method sulphur removing and dust removing technology

Abstract

The invention provides a sintering flue gas wet desulfurization and dust removal process. After the sintering flue gas is pressurized, it is cooled and defluorinated first, so that the HF in the flue gas is captured by the lye and the temperature of the flue gas is lowered to below 80°C; then the flue gas enters the high-efficiency desulfurization absorption tower, and is circulated through the jet pipe in the tower. The function of the flow device makes the flue gas swirl into the slurry pool at high speed, the flue gas is broken in the slurry and fully mixed with the slurry to complete the desulfurization and dust removal process; the net flue gas after demisting is reheated by the sintering waste heat steam from the Chimney exhaust. The desulfurization and dust removal process can achieve a desulfurization efficiency of more than 95% and a dust removal efficiency of 99%. The setting of the cooling defluorinator ensures the thermal safety of the absorption tower and reduces the degree of corrosion inside the tower. The high-efficiency desulfurization absorption tower has no slurry circulation pump, and there are no moving parts in the tower, and the gas-liquid contact effect is good. The reheating method using sintering waste heat steam saves the conventional GGH, improves the stability of the system operation and reduces the system cost.

Description

technical field [0001] The invention relates to a sintering flue gas desulfurization and dust removal process, in particular to a wet desulfurization and dust removal process for iron and steel metallurgy sintering flue gas. Background technique [0002] At present, sintering flue gas has become SO in iron and steel smelting 2 However, domestic research on sintering flue gas desulfurization technology is basically blank, which has become a bottleneck restricting the development of my country's iron and steel industry. [0003] In order to solve the sintering flue gas SO 2 There are two main countermeasures for the emission problem. [0004] One is to choose low-sulfur fuel or add a desulfurizer to the sintering raw material to reduce SO 2 For example, Chinese patent CN1285415A desulfurizes during combustion by adding ammonia-containing compounds to the sintering raw materials. Due to the uneven distribution of additives in the material layer and the uneven temperature an...

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Problems solved by technology

However, the gas-liquid mass transfer efficiency of the spray tower is average. To remove such a low concentration of SO 2 , it is necessary to ensure that the spray slurry is fully covered on the section of the absorption tower, and even the coverage between the spray layer and the layer exceeds 200%, so the corresponding liquid-gas ratio (W / G) is relatively large (generally W / G is 12 ~20), the power consumption is very large, and the economy is poor

[0009] (2) Compared with the flue gas of coal-fired boilers, the particle size of dust particles in sintering flue gas is smaller, and the proportion of submicron dust is higher. The dust removal efficiency of traditional spray towers in this particle size range is not high

[0010] (3) The temperature of the sintering flue gas from the electrostatic precipitator is relatively low (85-150°C), which makes it impossible for the regenerative gas-gas heat exchanger (GGH) at the front of the spray tower to recycle the purified flue gas heat above 80°C

Moreover, the composition of the sintering flue gas is complex, which will worsen the working condition of the GGH, which is already easy to block, thereby reducing the availability of the system

[0011] (4) The composition of sintering flue gas is complex. According to the difference of sintering ore, each cubic meter of sintering flue gas contains dozens or even hundreds of milligrams of HF gas

[0012] Therefore, considering the particularity of sintering flue gas, it may not be feasible and uneconomical to completely copy the wet desulfurization process and spray tower widely used in power plant desulfurization to sintering flue gas desulfurization

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