August 13, 2018
The most important considerations in choosing an ultrasonic cleaning system are the size of the tank, the frequency of the system and the power it can handle. Accessories such as a cleaning tank temperature heater and a basket to hold the parts must also be considered. Once these basic characteristics are fixed and the type of system required for the cleaning application is clear, additional options are available that may improve cleaning performance and speed up the cleaning process, depending on the parts to be cleaned and the contaminants to be removed.
Cleaning Tank Heater
Ultrasonic cleaners work by generating microscopic bubbles that scrub surfaces clean and remove surface contamination. When contaminants are hard deposits, the bubbles work more slowly because the deposits either absorb some of their energy or are too hard to immediately be broken up and washed away. Typical deposits and contaminants of this type include grease, engine deposits and burnt oil or carbon.
Such contamination is difficult to remove by any cleaning method but heat usually helps soften the deposits or loosen them from the underlying surface. When the cleaning solution of an ultrasonic cleaning system tank is heated, the bubbles act much faster and the cleaning process is completed in less time.
Tank heaters are a useful option for ultrasonic cleaning systems but they have to be designed for the application. The cleaning solution may contain a mild solvent but it is mostly water that boils at 100 degrees centigrade. As a result, the heat settings should be controlled to make sure the cleaning solution does not start boiling.
The cleaning tank also contains ultrasonic transducers that work with electronic parts sensitive to high temperatures. If the cleaning solution is going to be heated to a point just under boiling temperatures, the transducers must be able to withstand 100 degree centigrade heat. For applications that require the tank heater option, making sure that the system is designed to support it is critical.
Using Sweep Frequencies
An ultrasonic cleaning system is designed to operate at a certain frequency at which optimum cleaning results are achieved due to the size of the microscopic bubbles and the cleaning action intensity. At a given frequency, a system may experience a number of unpredictable negative effects. There may be dead spots in the cleaning tank where ultrasonic waves cancel each other out and no cleaning occurs. Resonance vibrations may appear and threaten to damage equipment or the parts to be cleaned. Sweep frequency modes reduce these effects.
When using sweep frequencies, the ultrasonic cleaner frequency varies around a central value. If ultrasonic waves are cancelling out somewhere in the tank, changing the frequency slightly will stop this effect or displace it temporarily to another tank location. Overall, cleaning is more even. Changing the frequency also stops resonance vibrations because they occur at one particular frequency. Using sweep frequencies to continuously vary the operating frequency helps to achieve better cleaning performance.
Water Resonance System
A water resonance system treats water destined for the cleaning tank to promote the formation of cavitation bubbles and help ensure even cleaning action throughout the tank. The water treatment of a water resonance system provides an even distribution of nuclei essential to bubble formation. With the nuclei distributed evenly, bubbles form everywhere in the cleaning solution rather than mainly above the ultrasonic transducer. A water resonance system helps ensure even cleaning action on everything placed in the cleaning tank.
Kaijo Can Provide Ultrasonic Systems as well as Key Options
Kaijo works with many different manufacturers to supply of the right ultrasonic system to meet for their application requirements. The company can supply complete systems from its comprehensive line of ultrasonic products and it has optional features that include tank heaters, use of sweep frequency and water resonance. Specialists at Kaijo also help analyze a customer’s cleaning requirements and propose the most effective ultrasonic cleaning solution based on their specific cleaning requirements.