Pressure Drop And Mixing Characteristic Of A Reciprocating Metallurgical Furnace Based On Porous Medium Combustion

Metallurgical furnace with porous media and reciprocal system is mainly used for metal melting. It combines highly temperature air combustion technology with reciprocating superadiabatic combustion in porous media. The combination of these technologies can improve gas combustion efficiency and reduce pollutant emission. Pressure drop profiles of honeycomb regenerator, gases mixing characteristics of burner and flue gas delay time are studied by experimental research and numerical simulation.Firstly, pressure drop profiles in metallurgical furnace with porous media and reciprocal system was experimentally studied on a cold test setup. The effects of half-cycle, superficial velocities and porous medium structure on pressure drop profiles were investigated. The results show that the system exists a smallest period of pressure drop, and the half-cycle has no influence on the pressure drop profiles. It was found that pressure drip profiles varied with rectangle waves when the system was operated steadily and periodically. Results show that superficial velocities and pore size of porous medium in the part of combustion have strong influence on pressure drop, while pore size of porous medium in the part of heat accumulation has relative small effect. In hot state resistance coefficient is relevant with temperature and velocity.Secondly, gases mixing characteristics of burner of the metallurgical furnace is studied by research. Half-premixed burner which is applied in industrial furnace can effectively avoid tempering problems, but it cannot guarantee gas mixing well in the burner. In order to improve combustion efficiency, it is necessary to study gas mixing characteristic of a half-premixed burner. Mixing characteristics of half-premixed burner was studied by experimental research and numerical simulation. Mixing characteristics which contain the velocity ratio of air and flue, the position of gas vents and preheating temperature was studied. The results show that increasing the velocity ratio of air and flue can make mixing characteristics better and the peak of gas concentration in the same section was move to the wall of the burner when the velocity ratio of air and flue become bigger; putting the position of gas vents in the front of the airflow distribution device can make mixing characteristics better than putting gas vents behind the airflow distribution device; increasing air preheat temperature can make gas concentration distribution more uniform.Lastly, combustion characteristic and flue gas delay time are studied through measuring composition of the burner and exhaust gas by comparing the research data in cold state with the research results in hot state. The results show that combustion characteristic of the central and the bottom positions are much better than the upper position; when the velocity of the air decreases, CO concentration fluctuation range in tail gas will increase during the system is reversing and flue gas delay time should increase. Therefore, the flue gas delay time is related to the velocity ratio of air and flue. When the velocity ratio of air and flue increases, the flue gas delay time will decrease and when the velocity ratio of air and flue decreases, the flue gas delay time will increase.