Cleaning Equipment

In an ultrasonic cleaner, the object to be cleaned is placed in a chamber containing a suitable solution (in an aqueous or organic solvent, depending on the application). In aqueous cleaners, surfactants (e.g., laundry detergent) are often added to permit dissolution of nonpolar compounds such as oils and greases. An ultrasound generating transducer built into the chamber, or lowered into the fluid, produces ultrasonic waves in the fluid by changing size in concert with an electrical signal oscillating at ultrasonic frequency. This creates compression waves in the liquid of the tank which ‘tear’ the liquid apart, leaving behind many millions of microscopic ‘voids’ or ‘partial vacuum bubbles’ (cavitation). These bubbles collapse with enormous energy; temperatures and pressures on the order of 5,000 K and 20,000 lbs per square inch are achieved; however, they are so small that they do no more than clean and remove surface dirt and contaminants. The higher the frequency, the smaller the nodes between the cavitation points, which allows for cleaning of more intricate detail.