1
Samuel L Sachs, Freeman K Hill: Ultrasonic cleaning method and apparatus for heat exchangers. The Johns Hopkins University, Robert E Archibald, Samuel Louis Sachs, January 13, 1981: US04244749 (30 worldwide citation)

Biofouling is removed from the external surfaces of spaced apart pipes of a heat exchanger which are in contact with a liquid by positioning a plurality of ultrasonic transducers between the pipes and operating the transducers at sufficient power levels to cause cavitation within the liquid to effec ...


2
Samuel L Sachs, Freeman K Hill: Ultrasonic cleaning method and apparatus. The Johns Hopkins University, Robert E Archibald, Samuel L Sachs, Leonard W Pojunas, March 8, 1983: US04375991 (23 worldwide citation)

An ultrasonic cleaning apparatus which is configured for transportation to an object positioned for use for in situ cleaning and a method for accomplishing the cleaning. In one embodiment, the present invention provides a substantially planar transducer array which can be employed to clean biofoulin ...