POWER ULTRASONIC EQUIPMENT - PRACTICE AND APPLICATION

Based on a paper presented at the Sonochemistry Symposium, Annual Chemical Congress, held at Warwick University, UK. By J P Perkins Sonic Systems Ltd, Bakers Farm Barns, Puckington, Ilminster, Somerset TA19 9JA UK Telephone: +44 (0) 1460 52123 email: info@sonicsystems.co.uk Download PDF Version Introduction With chemists turning more and more to ultrasound as a source of energy for the acceleration or modification of chemical reactivity, so it becomes increasingly important that they understand some of the ultrasonic engineering principles which underpin the whole topic of sonochemistry. This article is intended to provide an introduction to the principles of generation of ultrasound for the non-specialist. It is to be hoped that a chemist, armed with this information, will be in a much better position to decide on the type of equipment most appropriate for the intended laboratory application. The majority of chemists who have an interest in sonochemistry will naturally have acquired some familiarity with the types of ultrasonic equipment used for their work. However, with the increased usage of ultrasound in chemistry, as evidenced by the large number of sonochemical papers currently being published in the literature, more chemists are seeking information on the choice of equipment available and those already in the field may well be looking for more refined instrumentation. As part of any refinement one would expect a move towards some means of monitoring acoustic performance. The purpose of this article is to explore some of the principles behind the generation of power ultrasound. In doing so it is hoped that a practising chemist may gain not only a better knowledge of these fundamentals but also an appreciation of some of the parameters which ought to be monitored when applying acoustic energy in fundamental sonochemical studies. There are two basic methods of applying acoustic power to liquid loads (see Figure 1).