July 30, 2018
Industrial ultrasonic cleaners can clean parts quickly and completely if they have the right characteristics for the application. Ultrasonic cleaning systems are made up of a generator, one or more transducers, and a cleaning tank. Each component has to be selected correctly and they have to work together for the system to live up to its cleaning potential. Systems can be designed to clean one kind of part or they can be flexible and clean many different kinds. The key to selecting the right system is to be clear about what cleaning has to be done and what the required result should be.
The Cleaning Application
Cleaning parts effectively depends on the kind of part that has to be cleaned and the type of contaminants that are on the parts. When the right industrial ultrasonic cleaner is used, the surfaces of the parts to be cleaned are unaffected while the substances that have to be removed are washed away quickly. Ultrasonic cleaners remove light contamination such as dust, films and residue quickly and completely, even when the parts are odd shapes or have holes, cracks and crevices. The ultrasonic cleaners act wherever the cleaning solution can penetrate so interior cavities are also cleaned as long as the cleaning solution can enter.
When contamination is heavy, additional measures may be appropriate. For thick deposits of oil or grease, heating the cleaning solution helps speed cleaning because the oil and grease become softer and easier to remove. For some difficult deposits, mild solvents that act on the contaminant may also help clean the parts. If a cleaning application falls into these categories, the ultrasonic cleaning system should be able to handle solvents and heat the cleaning solution.
Size and Power
The size of the parts to be cleaned determines the cleaning tank size and influences the power required for the industrial ultrasonic cleaner. For unusually shaped parts, such as long thin parts or large flat ones, a custom tank may be appropriate to avoid having to power a large amount of cleaning solution, most of which is empty. In any case, the tank has to be slightly larger than the longest dimension of the parts to be cleaned.
Larger tanks will need more power but the most important factor is that the ultrasonic waves have to be evenly distributed and reach all sections of the cleaning tank. Too much power may cause pitting on the surfaces of the parts so buying a system with the right power is important. A competent manufacturer can help select the required power levels or recommend a system for which the power level is adjustable, depending on the cleaning application.
How to Immerse the Parts to be Cleaned
Since ultrasonic cleaning is carried out by means of high-frequency sound waves in the cleaning solution, both the tank walls and the parts to be cleaned may vibrate slightly as cleaning takes place. This means parts must be suspended in the cleaning solution to avoid contact between the parts and the tank walls or bottom because the vibrations can cause damage.
A basket that fits inside the tank can hold the parts safely suspended in the cleaning solution but the cleaning tank will have to be slightly larger to accommodate the basket. Baskets are usually stainless steel but they can be coated to hold delicate parts without scratching.
Kaijo’s Experts can Provide Help
With extensive experience in industrial ultrasonic cleaning systems, Kaijo can help customers select the ultrasonic cleaner best suited to their needs. Kaijo will provide free consultation on size, power, baskets as well as the appropriate frequency to use for a given cleaning application. They offer an extensive product line of ultrasonic cleaning equipment to address the needs of many different kinds of industrial cleaning applications.
July 17, 2018
Ultrasonic cleaning systems are composed of a signal generator, an ultrasonic transducer and a cleaning tank. The transducer changes the electrical high-frequency signal from the generator into ultrasonic sound waves in the cleaning solution. Due to this key role, it is important to choose a transducer that will work well with the generator and cleaning tank but also perform as expected for the cleaning application.
Ultrasonic Cleaning transducers have to deliver ultrasonic power in the liquid of the cleaning tank and withstand difficult operating environments without failure or reduced performance. Different types are available and some may be more suitable for specific cleaning tasks. Getting the best transducer means selecting the right type, designed by an experienced manufacturer and built with high-quality materials.
How an Ultrasonic Transducer Works
Kaijo’s ultrasonic cleaning transducers are made up of an electrical section that receives the electric signal from the ultrasonic generator and a mechanical section that vibrates at high frequency to generate the sound waves in the cleaning solution. Once received, the electric signal is applied across piezoelectric crystals that change the signal into vibrations. A heavy metal sheet is attached to the crystals and amplifies the vibration over a larger area. The whole construction is enclosed in a stainless-steel housing with the vibrations transmitted through the steel to the outside. When the transducer is immersed in the cleaning solution, the vibrations result in corresponding ultrasonic waves in the liquid.
Sound waves are compression waves that travel through the liquid as compression peaks and troughs. In the troughs, cavitation bubbles form due to the low pressure, and the bubbles collapse again in the high-pressure peaks. The collapsing bubbles release an energetic jet of cleaning solution that dislodges dirt and contaminants from the surface of the parts. The scrubbing action of these jets results in effective and rapid cleaning of the parts without damaging the underlying surface. Cleaning is thorough and takes place even in places that are inaccessible for conventional cleaning methods.
Type of Transducers
Different types of ultrasonic cleaning transducers are suitable for different cleaning applications. Kaijo offers immersible transducers, bolt-on transducers or mounted units depending on the cleaning system configuration. The transducers can be purchased separately, as individual units, or as part of a turnkey system.
Immersible transducers are the most flexible. They can be placed in any tank in the cleaning solution and will work whether they are horizontal or vertical, as long as they are completely immersed. These transducers are ideal for installing in an existing tank or an existing cleaning system for which ultrasonic cleaning is being added.
Bolt-on or mounted transducers are more permanently installed and can be part of a new system. The transducers are mounted or bolted onto the walls or bottom of the cleaning tank. For large tanks, several transducers may be needed to evenly fill the tank with ultrasonic waves.
Ultrasonic Transducer Characteristics
Ultrasonic transducers have to withstand the conditions present in the cleaning solution without damage. This means their surfaces have to be immune to pitting from exposure to ultrasonic waves and the housing must be waterproof. Ultrasonic cleaning solutions are sometimes heated and they may contain mild solvents. Transducers should continue to deliver rated performance under such operating conditions.
Kaijo has a complete line of ultrasonic transducers to meet the most demanding industrial cleaning requirements. Typical is the 40 kHz ultrasonic transducer, which will deliver 600 W or 1200 W of power, operate in up to 100 degrees centigrade liquids and which comes in a rugged hermetically sealed 316L stainless steel housing. Kaijo can help customers with their selection of ultrasonic transducers based on the company’s long-standing expertise in the ultrasonic cleaning field and can follow up recommendations with offers from their full line of transducers.Read More