In order to remove hydrogen in the aluminum liquid, the Silicon Nitride Ceramic hollow degassing rotor is used to feed nitrogen or argon, and the gas is dispersed by high-speed rotation,finally achieve the effect of neutralizing and discharging hydrogen. ï?¬Compared with graphite rotor, Silicon Nitride Ceramic will not be oxidized under high temperature environment, so it will not pollute the aluminum liquid, and the service life is much longer; ï?¬The property of high thermal shock resistance ensures that the degassing rotor will not break during frequent intermittent operation; Because Silicon Nitride Ceramic is of high density and high strength, it assures that degassing rotor can be reliable and stable in high speed rotation.