Method for recovering waste heat of high-temperature fuel gas of smelting furnace

Abstract

The invention relates to a method for recovering waste heat of high-temperature fuel gas of a smelting furnace. The method is characterized in that a conventional heat exchanging type combustion mode is operated when the furnace is started or in low-temperature combustion, and a thermal storage type combustion mode is operated when the temperature of the furnace is higher than 950 DEG C. The method is realized through a system for recovering waste heat of high-temperature fuel gas of the smelting furnace. The system comprises the smelting furnace, a thermal storage type regenerative burner system, a fume exhaust induced draft fan, a fuel gas circulation fan and a convection and radiation heat exchanger. According to the waste heat gradient utilization principle and difference of heating loads of the furnace, waste heat resources of fuel gas are recovered in the thermal storage mode and the heat exchanging mode properly, the advantages of the two modes are fully utilized, the waste heat recovery methods are automatically switched according to different temperatures of fuel gas in the furnace, the fuel gas is preheated and returns to the furnace through a flowing fire blocking wall in the furnace, high-temperature fuel gas waste heat is recycled to the maximum extent, waste heat recovery efficiency is improved, energy is effectively conserved, and it is guaranteed that the system can safely and stably operate.

Description

technical field [0001] The invention relates to the field of recovery and utilization of industrial furnaces and flue gas waste heat resources, in particular to a method for recycling high-temperature flue gas waste heat of a smelting furnace. Background technique [0002] Traditional smelting furnaces have problems such as small capacity, high energy consumption, large burning loss, poor operating environment, and severe local overheating and overburning, which lead to inconvenient component control in the smelting process, low production efficiency, and low product yield. [0003] The traditional smelting furnace has no smoke and dust settlement structure, and the smoke and slag are discharged with the flue gas, which is not up to environmental protection standards; or, the smoke and slag are discharged with the flue gas to block the heat storage body, which in turn causes the heat storage body to burn or melt, resulting in accidental shutdown. furnace. [0004] The flue ...

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Problems solved by technology

[0002] Traditional smelting furnaces have problems such as small capacity, high energy consumption, large burning loss, poor operating environment, and severe local overheating and overburning, which lead to inconvenient component control in the smelting process, low production efficiency, and low product yield

[0003] The traditional smelting furnace has no smoke and dust settlement structure, and the smoke and slag are discharged with the flue gas, which is not up to environmental protection standards; or, the smoke and slag are discharged with the flue gas to block the heat storage body, which in turn causes the heat storage body to burn or melt, resulting in accidental shutdown. furnace

[0004] The flue gas waste heat recovery method of the traditional smelting furnace mainly adopts the following two methods: 1. The metal heat exchanger is used to preheat the air with high-temperature flue gas. This waste heat recovery method is inefficient and cannot fully recover the waste heat of high-temperature flue gas. Furnace thermal efficiency is generally below 50%

The second is to preheat the air and gas to above 900°C by using the high-temperature flue gas waste heat above 1100°C through the ceramic regenerator, so as to realize the efficient recovery of the waste heat of the flue gas; The smoke exhaust method is different from the traditional heating furnace. It is not suitable for the initial start-up of the furnace and the low-temperature operating conditions. During the production process, there are often fluctuations in the furnace pressure, sucking cold air or serious fire from the furnace door, and even burn out the furnace door and the steel structure of the furnace body. , frequent accidents often affect production, and there is still the problem of large oxidation burning loss

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