Energy-saving and waste-reducing flue gas recycling jacket rotary kiln and application thereof

Abstract

The invention discloses an energy-saving and waste-reducing flue gas recycling jacket rotary kiln and application thereof. The rotary kiln comprises a kiln head, a kiln body, a combustion chamber and dustsettling chambers; the kiln body comprises an outer kiln and an inner kiln located in the outer kiln, and the combustion chamber is arranged at the joint of the kiln head and the outer kiln; the dustsettling chambers comprise the first dust settling chamber and the second dust settling chamber, and the first dust settling chamber and the second dust settling chamber are separated from each other; the first dust settling chamber is connected with the inner kiln and used for collecting and treating flue gas of the inner kiln; the second dust settling chamber is connected with the outer kiln and used for collecting and treating flue gas of the outer kiln; and a flue gas outlet of the first dust settling chamber is connected with the combustion chamber, and the combustion chamber is used for combusting the flue gas flowing out of the first dust settling chamber. According to the energy-saving and waste-reducing flue gas recycling jacket rotary kiln and the application thereof, a conventional treatment path for the flue gas of the rotary kiln in the prior art is broken through for the first time, the quality-divided and flow-divided treatment of the fuel combustion flue gas (namely the flue gas of the outer kiln) and the material pyrolysis waste gas (namely the flue gas of the inner kiln) is realized, and secondary combustion of gaseous pollutants in the flue gas and fuel which is not fully combusted is realized.

Description

technical field [0001] The invention belongs to the field of flue gas utilization of a rotary kiln, and in particular relates to a rotary kiln with an energy-saving and waste-reducing flue gas recirculation jacket and an application thereof. Background technique [0002] The incineration method can maximize the harmless and reduction treatment of hazardous waste, municipal sludge and domestic waste. At present, more than 90% of hazardous wastes and a large amount of urban sludge and household wastes in the country are treated by incineration. Most of the equipment used by the hazardous waste incineration treatment enterprises established in various parts of our country adopts the rotary kiln system. [0003] Rotary kiln is a rotary calcining kiln or sintering kiln, which is widely used in many production industries such as building materials, metallurgy, chemical industry and environmental protection, for calcining, incinerating or sintering solid materials. For example, i...

AI Technical Summary

Problems solved by technology

However, because the flue gas composition contains fuel combustion flue gas, material pyrolysis waste gas and a large amount of water vapor, the total amount of flue gas is huge, so its secondary incineration consumes a lot of energy, resulting in high treatment costs

However, when this method is used to treat the exhaust gas of the rotary kiln, its disadvantages are: (1) The combustion of the fuel produces a large amount of flue gas, and the temperature has dropped to about 200-300 °C after the countercurrent heat exchange with the material. , it needs to be reheated to above 850°C-1100°C, and a large amount of gas is re-added to high temperature, which greatly increases energy consumption; (2) After the material is heated, the moisture in it will be mixed into the exhaust gas in the form of water vapor, and a large amount of water vapor also needs to be added. High temperature will greatly increase unnecessary energy consumption; (3) The cost of dioxins in the flue gas is extremely high, because it is necessary to ensure sufficient temperature and sufficient residence time, etc.

[0006] To sum up, the currently widely used rotary kiln system for hazardous waste treatment has huge environmental risks. A large amount of gaseous organic pollutants produced by the materials are introduced into the atmosphere by the induced draft fan before reaching the high temperature section, including secondary Strong carcinogens such as oxins, causing serious air pollution; secondary incineration flue gas terminal treatment costs are high and the effect is not good

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