Waste heat boiler system, rotary hearth furnace high temperature dusty flue gas treatment system and method

Abstract

The invention relates to a waste heat boiler system, a rotary hearth furnace high-temperature dust-laden smoke treatment system which is provided with the waste heat boiler system and a method for rotary hearth furnace smoke treatment applying the rotary hearth furnace high-temperature dust-laden smoke treatment system. According to the invention, an external smoke inlet is arranged on a sedimentation furnace of the waste heat boiler system, so that external high-temperature smoke is introduced in for diluting to-be-treated smoke; the dust concentration and harmful content concentration in the smoke are lowered; dust is prevented from being accumulated on the sedimentation furnace, a high-temperature heat exchange part and a low-temperature heat exchange part; the probability that smoke treatment equipment and a flue are blocked is lowered; meanwhile, corrosion of the smoke to the sedimentation furnace, the high-temperature heat exchange part, the low-temperature heat exchange part, the flue and the like is alleviated; stable operation of the waste heat boiler system and the rotary hearth furnace high-temperature dust-laden smoke treatment system is ensured; and the service life of the equipment is prolonged. Meanwhile, qualities of the smoke such as temperature can be ensured by the external high-temperature smoke, and the smoke waste heat utilization efficiency is ensured.

Description

technical field [0001] The invention relates to a waste heat boiler system, a rotary hearth furnace high-temperature dusty flue gas treatment system equipped with the waste heat boiler system, and a method for treating rotary hearth furnace flue gas by using the rotary hearth furnace high temperature dusty flue gas treatment system. Background technique [0002] In 2015, China's crude steel output was 802 million tons, making it the world's largest steel producer. Rotary hearth furnace direct reduction ironmaking process is a new ironmaking process developed in China in recent years. In recent years, it has been gradually promoted and applied in some domestic iron and steel enterprises. The rotary hearth furnace emits a large amount of high-temperature flue gas during the production process, and the waste heat of the high-temperature flue gas (1000-1200°C) in the normal production process of the rotary hearth furnace is recovered to generate electricity, and the high-concent...

AI Technical Summary

Problems solved by technology

[0003] 1) The flue and heating surface are blocked

Blockage is prone to occur in high-temperature flue and low-temperature flue, etc.

Rotary hearth furnace raw materials have various sources, complex components, and frequent changes, resulting in complex flue gas components, and the flue gas contains alkali metal chlorides; the boiling point and melting point of alkali metal chlorides are low, in the range of 600-500 ° C, some alkali Metal chlorides undergo a gas-liquid phase transition in this section, and the halides bond to cause blockage; in the range of 200-300 ° C, alkali metal chlorides begin to condense, absorb moisture in the flue gas and deliquescence into hydrates, hydrates Strong corrosion and serious damage to equipment. In addition, hydrates will combine with flue gas dust to form dense bonds, which will cause blockage of the flue gas treatment system and affect system operation stability and running time.

[0004] 2) Corrosion of the heating surface

The high-temperature flue gas of the rotary hearth furnace contains acid gas elements such as Cl and S. After the temperature of the flue gas is lowered, dew condensation can be produced to produce acidic liquid, resulting in low-temperature corrosion

The flue gas temperature of the rotary hearth furnace is as high as 1000-1200°C, and the flue dust is rich in alkali metals such as K and Na, which may easily cause alkali metal corrosion of equipment and flue

[0005] 3) The thermal efficiency is low. The flue gas of the rotary hearth furnace is generally recovered and utilized by conventional power plant boilers, and the heat recovery efficiency is relatively low.

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