The process of ice slurry preparation is observed with the ice slurry preparation equipment based on vacuum stirring method

and the effects of ethylene glycol additive

solution volume and stirring speed on the supercooling degree of ice slurry preparation are investigated experimentally. The results indicate that the procedure of ice slurry preparation under vacuum can be divided into four stages

including solution evaporation

boiling

supercooling

and ice crystal generation. The system pressure increases at the instant of ice crystal generation and the pressure variation which is defined as supercooling crystallization pressure difference can characterize the supercooling degree. The higher the concentration of ethylene glycol additive

the smaller the average supercooling crystallization pressure difference

which is down to 49.4 Pa from 58.9 Pa when the concentration of ethylene glycol additive is varied from 3% to 6%. Furthermore

the increase of solution volume can also reduce the average differential pressure which is dropped by 12.9% when the solution volume is varied from 20 mL to 40 mL. The stirring speed has little influence on supercooling crystallization pressure difference.