Contrast experiments on scaling effect using ultrasonic scaling method on the commercial water boilers are performed and the formed water scale is analyzed by SEM (scanning electron microscopy). Results show that ultrasonic can accelerate the formation of the scale microcrystal nucleus. The ultrasonic scaling method can promote the scale of the heating tube with high temperature on commercial water boilers

while it decreases the scale on the low temperature plate

such as water tank surface. Since the scale is mainly taken place on the heating tube

this method is not suitable for commercial boiler.