超声波对脱气与未脱气氯化铵溶液结晶的影响

为了阐明超声波强化饱和溶液结晶的机理,分别研究了超声波对脱气饱和氯化铵溶液与未脱气饱和氯化铵溶液结晶的影响。结果显示,在相同超声波辐射下,脱气饱和氯化铵溶液与未脱气饱和氯化铵溶液的结晶均得到了强化,但未脱气饱和氯化铵溶液白浊化开始时间显著小于脱气饱和氯化铵溶液白浊化开始时间,未脱气氯化铵溶液结晶晶粒比脱气氯化铵溶液结晶晶粒更细小。这表明超声空化以及声场中溶液分子振动引起的能量、温度及密度的波动对饱和溶液的结晶均有影响,但空化是强化饱和溶液结晶的主要因素。

Influence of ultrasonic waves on crystallization of ammonium chloride solution and degassed solution

In order to clarify the enhancement mechanism of saturated solution crystallization by ultrasound,the effects of ultrasonic waves on crystallization process of saturated ammonium chloride solution and degassed so-lution are investigated by using a novel ultrasonic cold stage device.The results show that the use of ultrasound could accelerate the crystallization process of both ammonium chloride solution and degassed solution,but the cooling rate and cloudiness time of ammonium chloride solution are much less than those of degassed solution.Furthermore,sonocrystallisation of ammonium chloride solution can result in smaller crystals than those induced by sonocrystallisation of degassed solution.It is concluded that cavitation and fluctuations of density,energy and temperature induced by ultrasound are factors that affect the crystallization process of saturated solutions.But cavitation is a major factor for the enhancement of saturated solution crystallization.