Sintering smoke wet method sulphur removing and dust removing technology

Abstract

The invention provides a wet desulfuration and dust-removing technology of sintered flue gas. After the pressure is boosted, the sintered flue gas is firstly processed cooling and defluorination, enabling the HF in the flue gas to be collected by alkaline solution and the temperature of the flue gas to be reduced below 80 DEG C, and then the flue gas enters a highly-effective desulfuration absorption tower. The flue gas is rotatablely punched into a slurry pool with high speed by the function of a rotary current device installed inside a projecting tube arranged inside the tower, and then the flue gas is crushed in the slurry and is fully mixed with the slurry, consequently the process of desulfuration and dust-removing is finished. The pure flue gas after being demisted is discharged from a chimney after being heated by the sintered steam. Above 95% desulfuration efficiency and 99% dust-removing efficiency can be realized by the desulfuration and dust-removing technology. The arrangement of a cooling defluorinated device ensures the hot safety property of the absorption tower and reduces the corrosive degree of the inner tower. The highly-effective desulfuration absorption tower is not provided with a slurry circulation pump, and no moving member is installed inside tower, thereby the contacting effect of gas and liquid is perfect. The reheating method by the sintered steam saves the normal GGH, increases the stability of the systematic operation, and reduces the systematic fabrication 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

[0008] (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

[0009] (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

[0010] (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

[0011] 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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