Simulation Research And Industrial Application Of Airlift

Airlift reactors are gas-liquid(or slurry) contacting devices which have advantages like simple structure, low cost, easy to seal, and low power consumption. They are to the benefit of reactants mixing, diffusion, heat and mass transfer. So airlift reactors have been widely used in the industry. Further investigation of airlift reactors is very important for design and amplification of such reactors.Parameters of the behavior of airlift reactors are hydrodynamic parameters such as gas holdup, superficial gas velocity, liquid circulation velocity, pressure difference and structural parameters such as height to diameter ratio and diameter ratio, etc. The airlift reactors were optimized for simulation research and engineering practice with hydrodynamic parameters and structural parameters.The relationship between the superficial gas velocity, liquid circulation, gas holdup in riser and pressure difference at different effective depth, height to diameter ratio and diameter ratio were studied for the system of air-water in airlift reactor. When the superficial gas velocity was low, the larger the superficial gas velocity, the higher the gas holdup. However, as the superficial gas velocity went on increasing, the gas holdup sharply increased between 0.017 m/s and 0.021 m/s. The liquid circulating velocity increased with increasing superficial gas velocity. The relationship between the the riser linear liquid velocity UL to the riser superficial gas velocity was theoretically by U_L = 1.2555U_G^1.3788, The pressure difference sharply increased with increasing superficial gas velocity. Under the different effective depth, the liquid circulation velocity of 160 cm increased faster than 161 cm. The gas holdup was less influenced by the effective depth. The bigger the superficial gas velocity, the higher the pressure difference. The gas holdup increased faster with larger height to diameter ratio than those with smaller ratio. The bigger the diameter ratio, the higher the liquid circulation amount. The gas holdup decreased with increasing diameter ratio; the smaller the diameter ratio, the larger the pressure difference.Airlift reactor was applied to wastewater treatment, the results showed that the process had stable treatment efficiency, strong resistance to shock loading and can meet the project requirements. This provides an example for industrial applications of the airlift reactor.