To prevent scale buildup inside by transferring ultrasonic vibration to the inside of an outer pipe without causing cavitation erosion of an outer surface of the outer pipe of a double pipe-type heat exchanger.
This scale prevention device includes a heating section 2 for heating the water while storing the water inside or allowing the water to pass therethrough, a propagation tank 1 disposed while covering the heating section 2, and storing nonvolatile liquid or a propagation medium 3 of which a dispersion medium is composed of nonvolatile gel, so that the heating section 2 is soaked in the propagation medium 3, an ultrasonic wave vibrating means 4 propagating the ultrasonic wave vibration to the water in the heating section 2 by vibrating the propagation medium 3 by ultrasonic to separate substances attached to the inside of the heating section, and a control section 8 controlling the ultrasonic wave vibrating means 4 and the heating section 2. Cavitation is not generated on an interface between the heating section 2 and the propagation medium 3, but generated in the water in the heating section 2.
FUKUMOTO MASAMI
Hiroki Naito
Daisuke Nagano