Multi-radiation evaporation screen afterheat boiler

Abstract

The invention discloses a multi-radiation evaporation screen afterheat boiler. The multi-radiation evaporation screen afterheat boiler comprises a flue gas inlet, a flue gas flow equalizing chamber, a water-cooling radiation heat exchange chamber, a radiation evaporation screen, a film type water cooling wall, a convective heat exchange chamber, an evaporator, a coal saver, a steam pocket, a dust discharging device and the like. High-temperature flue gas enters the flue gas flow equalizing chamber from a flue gas inlet of the afterheat boiler, after being equalized, the flue gas enters the water-cooling radiation heat exchange chamber, after exchanging heat with the film type water cooling wall and the radiation evaporation screen, the flue gas enters the convective heat exchange chamber again, after the flue gas exchanges heat with the evaporator and the coal saver, the temperature of the flue gas is greatly reduced, the flue gas is exhausted from a boiler system, and after being de-dusted, the flue gas is exhausted; the afterheat boiler absorbs the heat of the high-temperature flue gas, and the generated steam is used for production or generating electricity. The afterheat boiler can fully reclaim the heat of the high-temperature and high-dust content flue gas of an arc furnace, convertor and the like, the temperature of the absorbed flue gas can be up to 1,600 DEG C, and the reclaimed heat can be up to over 70 percent of the heat of the exhausted flue gas; the equipment of the reclaiming system is stable and reliable in operation, and the maintenance cost and the operation cost are low.

Description

technical field [0001] The invention relates to a waste heat boiler for recovering waste heat of high-temperature and high-dust flue gas. Specifically, the multi-radiation evaporation panel waste heat boiler can efficiently recover waste heat of high-temperature and high-dust flue gas such as electric arc furnaces and converters, and reduce the exhaust gas temperature to the greatest extent. , efficiently recovering the waste heat of the flue gas, ensuring the safe operation of the dust removal equipment, and reducing the power consumption of the dust removal, which belong to the technical field of energy saving and environmental protection. Background technique [0002] At present, in the production process of electric arc furnace steelmaking, converter steelmaking and closed submerged arc furnace, the temperature of the high-temperature and high-dust flue gas discharged is very high, generally at 1300 ° C ~ 1800 ° C, the dust content in the flue gas The amount reaches 30g / ...

AI Technical Summary

Problems solved by technology

There are many disadvantages in the above cooling methods: 1. The resistance of the vaporization cooling device is large, the exhaust gas temperature is high, the investment is high, and the floor area is large; The initial investment and operating costs of the fans, motors, and dust collectors of the flue gas, and waste the heat in the flue gas

3. Water-cooled flue cooling method: a large amount of cooling water is required for cooling, and cooling equipment and water treatment devices for cooling water are required, which not only wastes the heat in the flue gas, but also increases the power consumption and chemical consumption of the cooling water system

3. Spray cooling: Consuming cooling water and increasing the water content in the flue gas not only makes the dust bag easy to condense, but also easily causes the bag to fail in hydrolysis, and also wastes the heat in the flue gas

4. Heat pipe waste heat boiler cooling method: Since the heat pipe can only withstand the flue gas temperature of about 860°C, this method can only recover the heat of the flue gas below 850°C; the heat pipe of the heat pipe waste heat boiler has a short service life and high operating costs; Heat pipe waste heat boilers are large in size, occupy a large area, and require high investment

5. Waste heat boiler with flue gas screen, the patent number is 200820211388X. A water-cooled flue gas screen is installed in the radiant room. The flue gas screen is composed of curved and longitudinally arranged cooling water pipes. When used in high-temperature flue gas above 1000, the water in the elbow is easy to vaporize and accumulate on the top of the elbow, causing local overheating and burning; Extremely susceptible to wear and damage

Therefore, this type of boiler is not suitable for electric arc furnace steelmaking, converter steelmaking, etc., which have high dust content and ultra-high temperature flue gas waste heat recovery.

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