以煤气作为能源的熔化炉和烘干炉,按正常情况,熔炼一炉镁合金只需3～4h。若煤气燃烧不充分,有时甚至10多个小时还熔化不了。造成煤气燃烧不充分、制约熔化炉温度升高的主要原因是喷嘴与炉口墙板的封闭式联接(图1)。煤气燃烧所需的氧气(指空气中的氧)全由喷嘴上的空气调节阀来控制,但该调节阀由 To gas as a melting furnace and drying furnace, according to normal circumstances, melting a furnace magnesium alloy only 3 ~ 4h. If the gas does not burn well, sometimes even more than 10 hours can not melt. Resulting in inadequate combustion of gas, the main reason for restricting the temperature rise of the melting furnace is the closed connection between the nozzle and the furnace wall (Figure 1). The oxygen required for the combustion of the gas (oxygen in the air) is controlled entirely by the air-regulating valve on the nozzle, but the regulating valve consists of