19-08-2014, 10:39 AM
The application of the ultrasound in the homogeneous system has been extensively explored. In comparison, the ultrasound application in heterogeneous system is not much explored. In the present work, study of ultrasonic atomisation and emulsification has been carried out.
The application of the ultrasound in the homogeneous system has been extensively explored. In comparison, the ultrasound application in heterogeneous system is not much explored. In the present work, study of ultrasonic atomisation and emulsification has been carried out.
Atomisation is very important operation in chemical industries in spray columns for absorption, spray coatings, spray drying and formation of mist for certain chemical reactions. Ultrasonic atomisation is studied as a newer technique of atomisation for surface coating. In this work, the effect of various parameters on the % area of the spray collected on the sample paper (Whatman filter paper No.1) has been studied.
The experiments aim to observe the effects of various parameters like liquid flow rate, amplitude of the atomiser, linear velocity of the paper and the height of the atomiser from the paper on the % area of the spray collected on the paper. For this purpose a special belt conveyer was designed to move the sample paper. The liquid used was water with small amount of Rhodamine-B. The analysis of the sample papers was done with Biovis Image Analyser. A correlation is being developed to include the effect of all these parameters on the covered area.
The success of the heterogeneous liquid-liquid systems that may be reacting or non-reacting, depends on the ability to generate high interfacial area by an equipment economically. Ultrasound assisted cavitation generating equipment is a better solution when fine emulsions are required. The qualityof emulsion generated by sonication is far superior to that of conventional processes. The important advantage is that the generation of an emulsion does not require addition of surfactant.
Ultrasonic emulsification of oil and water has been carried out without using any surfactant. Vegetable oil and mineral oil were used to perform experiments so that the effect of the physicochemical properties can be studied. The effect of the various parameters on the stability, volume fraction of one phase into other and droplet diameter of dispersed phase has been studied. For comparative study, ultrasound emulsification has also been also carried out using minimal amount of non-ionic surfactant. The effect of the type of surfactant on emulsion quality has been studied.