Experimental research on antiscale and scale removal by ultrasonic cavitation

Abstract

Aiming at the scale problem in heat-transfer equipments, experimental investigation on antiscale and scale removal by ultrasonic cavitation is performed. By means of microscopic magnifying photography system, the sedimentary phenomenon can be observed. The experimental research reveals the influencing rule of acoustic intensity, cavitational distance, liquid temperature and solution concentration. The experimental results indicate that liquid temperature has different effects on antiscale and scale removal. Different experimental liquids are used for antiscale and scale removal experiments. The results show that every liquid has a respective cavitational active temperature. When ultrasonic is used for antiscale, the smaller acoustic intensity is, the better effect is. But, when ultrasonic is used for scale removal, acoustic intensity has a reverse influence. In addition, biggish solution concentration is propitious to antiscale for long-time running. Distance of test sample to ultrasonic transducer also has certain influence on antiscale and scale removal. The smaller the distance to ultrasonic transducer is, the better effects antiscale and scale removal have.

Influence of ultrasound to convectional heat transfer with fouling of cooling water

“…According to previous research [1,2,13] ultrasound when propagating in liquid may cause several important effects on fouling process, e.g. cavitational effect, shearing effect, active effect and mechanical effect.…”

“…Legay et al [12] simulated the descaling process of ultrasound by paint-spray experiment and got very good effect during a few tens of minutes of ultrasound treatment. Li et al [13] investigated ultrasound cavitations effect on antifouling and descaling and found the different cavitational active temperature for liquids and reverse effect of acoustic intensity.…”

Enhancement of Heat Transfer by Ultrasound: Review and Recent Advances

“…The result observed was that the use of ozone and ultrasound was more effective than each process alone. But optimal parameters are sometimes difficult to find, for example, concerning scale removal [91] with choice of temperature, distance, and acoustic intensity.…”

Dynamic behaviors of cavitation bubble for the steady cavitating flow

“…(5) The cavitating flow in the venturi is in the steady state, namely the mass flow rate is constant.…”

“…For example, the interchange of pressure and kinetic energy can be achieved in the case of flow through orifice plate, venture, etc. Cavitation has significant potential for application to various industries, such as drinking water disinfection [1,2], wastewater treatment [3], intensification of chemical reactions [4], antiscale and scale removal [5] and heat transfer enhancement [6][7][8][9].…”