Method for regulating and controlling circulating flue-gas temperature and oxygen content

Abstract

The invention discloses a method for regulating and controlling circulating flue-gas temperature and oxygen content. A thermometer, a flowmeter, a pressure meter and an oxygen amount analysis meter are arranged on a pipeline (14) for connecting sintering machine air boxes (6) and a large flue and a circular cooler hot exhaust gas circulating pipeline (24) and used for monitoring the temperature, flows, pressure and the oxygen content of smoke of the sintering machine air boxes and hot exhaust gas of a circular cooler and calculating the smoke of the air boxes and standard flows of the hot exhaust gas of the circular cooler. According to the requirement for the temperature of the smoke discharged by an electric dust remover of the large flue, the sintering machine air boxes for smoke exhausting are allocated. A regulating valve (23) installed on the circular cooler hot exhaust gas circulating pipeline is utilized to regulate the hot exhaust gas flows of the circular cooler so as to regulate and control the circulating flue-gas temperature and the oxygen content. The circulating flue-gas temperature and the oxygen content are actually measured through the thermometer and the oxygen amount analysis meter arranged on a connecting pipeline (6) between a sintering machine fan housing (5) and a mixer (17), the hot exhaust gas flows of the circular cooler are corrected, and accordingly the circulating flue-gas temperature and the oxygen content are accurately controlled.

Description

technical field [0001] The invention relates to waste gas emission reduction in sintering process and waste heat recovery and utilization of sintering machine waste gas, in particular to a method for controlling the temperature and oxygen content of circulating flue gas. Background technique [0002] The sintering process plays an extremely important role in the economic benefits of iron and steel enterprises and the recycling of resources. For example, in a company's blast furnace iron-containing charge, the cost of sintered ore is 180-350 yuan / ton lower than that of pelletized ore, and slightly lower than the cost of natural lump ore. The sintering process is a major energy consumer and pollutant emitter in steel production. A large amount of flue gas is generated during the sintering production process. The sintering flue gas contains a variety of complex environmental pollutants, such as dust, SO 2 , NOx, heavy metals (such as Cd, Hg, As, Pb, etc.), HCl, HF, volatil...

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Problems solved by technology

[0004] Chinese patent 200780002553.9 discloses a method for sintering on a sintering machine, the method is to divide the sintering machine into three sections along the traveling direction of the trolley, accounting for 15-25% and 50-65% of the length of the sintering machine respectively and 10-25%, and the sintering waste gas of the first and second sections is mixed and then added to the cooling machine exhaust gas or air as the process gas and sent to the second section of the cycle sintering method, the temperature of the circulating flue gas is required to be 90- 150°C, with an oxygen content of more than 15%, but there is no mention of the method of controlling the temperature and oxygen content of the circulating flue gas and how to ensure that the temperature of the exhaust gas entering the electrostatic precipitator is ≥80°C

[0006] In the currently disclosed technology of circulating sintering with sintering flue gas, it is mentioned that the temperature and oxygen content of the circulating flue gas should be controlled within a certain range in order to ensure the effect of circulating sintering, but none of them involve how to control the circulating flue gas Temperature and oxygen content and ensure that the temperature of the exhaust gas entering the electrostatic precipitator is ≥80°C

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