Article ID: 11we142
Flow and heat transfer characteristics of ammonium alum hydrate slurries treated with drag-reducing surfactants have been investigated experimentally. Ammonium alum hydrate has high latent heat of 251 kJ/kg and its fusion temperature is 51oC when the concentration of ammonium alum in water was set at 35 wt%. The friction and the melting heat transfer coefficients were measured in a pipe flow with 13 mm of diameter. From the results, it was found that ammonium alum hydrate slurries treated with surfactants show the effective drag reduction in a pipe flow. It was also found that the heat transfer of slurries with surfactants is reduced slightly especially in the cases of the high temperature difference between the slurries and the heating water flowing the outside of the test tube. However, the heat transfer of slurries with surfactants divided by pressure loss was very high and the particle growth due to the particle agglomeration could be depressed by surfactants. From this, it was concluded that the ammonia alum hydrate slurry with surfactant is a promising system as heat transportation media.
