RESEARCH ON CO DEFLAGRATION AND EXPLOSION PREVENTION IN THE ALL-DRY PROCESS OF GAS SENSIBLE HEAT RECOVERY FOR BASIC OXYGEN FURNACE

When the gas of basic oxygen furnace (BOF) is about 850 °C, water spray is generally used for cooling and dedusting, resulting in 50% of the sensible heat of the gas being wasted. In order to fully utilize the waste heat resources rich in CO gas during the converter steelmaking process, the new method cancels the water spraying process and adopts the converter gas fully dry sensible heat recovery system. However, this technology poses a risk of gas explosion during the pre and post combustion stages of the converter gas. In response to the safe and stable operation requirements of the full dry process system of the converter, this article investigates the effects of factors such as CO equivalence ratio, initial temperature of the mixed gas, and water content on CO deflagration characteristics through experiments and theoretical calculations. The results show that the maximum pressure and deflagration speed of CO deflagration decreases with the decrease of CO equivalence ratio in the mixed gas. But, when the CO equivalence ratio is less than 0.368, the effect on flame speed is not significant. Within the range of CO equivalence ratio in the experiment, the maximum deflagration pressure is 0.65 MPa, and the maximum deflagration speed is about 750 m/s; The initial temperature increase of the mixed gas leads to a decrease in the maximum deflagration pressure generated during the deflagration process, while the flame speed increases relatively, thereby affecting the flame propagation time. An increase in water content will lead to an increase in the maximum deflagration pressure of CO deflagration, but further increase after the water content reaches 0.463% has little effect on the maximum deflagration pressure; Finally, by analyzing the characteristics of CO deflagration and the actual production process, explosion-proof methods and technologies such as combustion control and enhancement, as well as gas explosion containment, were proposed to effectively reduce the losses caused by deflagration.