Equipment for circularly denitrating high-oxynitride flue gas from sintering machine

Abstract

The invention relates to equipment for circularly denitrating high-oxynitride flue gas from a sintering machine. The equipment comprises the sintering machine, a fan, dust removers and a desulfurizer. The equipment further comprises an upper fume hood, an iron ore distributing device, connecting pipelines and pipeline fittings, wherein the upper fume hood is arranged on the top of the sintering machine; and the iron ore distributing device, the connecting pipeline and the pipeline fittings are arranged on the sintering machine. The upper fume hood is connected with the circulating fan, and then is connected with a circulating dust remover; one path of the circulating dust remover is connected with a circulating pipeline which is communicated with the high-oxynitride area and low-oxynitride area of the sintering machine; and the other path of the circulating dust remover is connected with a gas-mixing adjusting pipeline which is provided with a gas-mixing adjusting valve. The circulating pipeline is not only connected with the sintering machine, but also sequentially connected with a main dust remover, the desulfurizer, the fan and a chimney through the connecting pipelines, so as to denitrate the high-oxynitride flue gas from the sintering machine. By adopting the denitrating equipment based on the flue gas circulation of the sintering machine, the efficiency for denitrating the oxynitride (NOx) from the circulated flue gas can be increased to 80-90% on the premise of not increasing the investment on equipment and construction, and the cost for energy consumption and operation.

Description

technical field [0001] The invention relates to the emission reduction of sintering flue gas circulation nitrogen oxides (NOx), which meets the requirements of national environmental protection policies, energy conservation, emission reduction and low-carbon economy, belongs to the technology for reducing emission of nitrogen oxides in sintering flue gas in the field of iron and steel metallurgy, and is a sintering flue gas nitrogen oxides emission reduction technology. Machine high nitrogen oxides flue gas circulation denitrification equipment. Background technique [0002] Sintering is an important process unit in steel production. A variety of air pollutants are produced during the sintering process, such as particulate matter, NOx, SO 2 , CO, HCl, HF, alkali metals, various heavy metals and various organic compounds including PCDD / F, etc. Sintering is the largest source of NOx emissions in iron and steel complexes. The NOx emissions of this unit account for 50% to 60% ...

AI Technical Summary

Problems solved by technology

[0004] The flue gas composition of the sintering machine is complex and fluctuates greatly, and has the following characteristics: First, the flue gas volume is large, and the flue gas volume produced per ton of sintering ore is 3500-5000m 3 (working conditions); Second, the NOx concentration fluctuates greatly, and the concentration range is generally 150-700mg / Nm 3 The third is that the flue gas temperature of each bellows varies greatly, generally between 50°C and 400°C; the fourth is that the flue gas flow rate varies greatly, and the variation range can reach about 40%; the fifth is that the moisture content in the flue gas is large and unstable, generally 10 % to 13%; Sixth, the oxygen content is high, generally 13% to 19%; Seventh, the flue gas contains a variety of pollutants, except particulate matter, SO 2 , NOx, it also contains alkali metals, heavy metals, PCDD / F and many other organic substances; eighth, the average concentration of NOx in the total flue gas is low, generally 250-400mg / Nm 3 , which is far lower than the flue gas of the olefin coal boiler in the power plant, which is not conducive to improving the removal efficiency; Ninth, if the SCR process of the power plant is copied to the sintering machine, the cost of removing NOx per unit will be astonishingly high due to the consumption of catalyst and ammonia reducing agent

[0005] Sintering machine flue gas circulation deNOx can achieve negative energy consumption operation, but only 60% to 70% of NOx in the circulating flue gas can be removed

Images