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
August 16, 2016
Industrial manufacturing facility managers and business owners are finding that ultrasonic cleaning systems offer significant advantages over traditional chemical-based cleaning methods. Ultrasonic systems provide significant operational cost savings because they don’t require the use of chemicals and the costs of compliance with environmental regulations. Ultrasonic systems clean faster and more effectively and can clean the surface of oddly shaped devices or parts. The main question that remains before making a purchasing decision is regarding the frequency that will be best for the particular cleaning application.
Ultrasonic cleaning systems operate at frequencies between about 20 kHz and 200 kHz. The cleaning system includes a generator, transducer and a cleaning tank. The transducer creates ultrasonic waves that produce bubbles in the water of the cleaning tank. Low frequencies generate larger bubbles and more intensive cleaning while the small bubbles of high frequencies will clean more gently. A 40 kHz ultrasonic transducer generates mid-range to large bubbles that clean a wide range of manufactured parts well but are not as aggressive as the large bubbles generated at the 20 kHz range.
Ultrasonic Cleaning System Components
In an ultrasonic cleaning system, a generator produces the high-frequency electric signal and the transducer converts the signal to sound waves in water. One or more transducers are located inside the tank that holds the cleaning solution and the parts to be cleaned. Transducers can be designed to handle different frequencies but they have to match the frequencies produced by the ultrasonic generator. The tanks are the same no matter what frequency is used.
For a 40 kHz generator, corresponding 40 kHz ultrasonic transducers can be immersible, bolt-on or tank mounted. Immersible transducers are supplied as separate units with an electrical cable connection and can be moved and placed anywhere in the cleaning tank. Bolt-on transducers are bolted onto the bottom or sides of a tank while mounted transducers are already installed.
Turnkey systems may come with a tank that has the transducers already mounted or has bolt-on transducers that can be changed for different frequencies. For customers purchasing just the transducers or wanting to retrofit an existing tank, the immersible or bolt-on transducers may be more appropriate because they offer more installation flexibility.
Parts to be Cleaned
The parts or components to be cleaned and the nature of contamination or dirt determine which frequency is the most appropriate for ultrasonic cleaning. Heavy deposits to be removed from robust parts require a low frequency with intensive cleaning. Delicate parts with only a dirty film or microscopic particles require high frequencies. The mid-range frequency of 40 kHz combines the most desirable features of both extremes.
For example, at 40 kHz, a cleaning system can effectively clean machined parts, industrial devices, ceramics, jewelry, electronics such as hard disk drive parts, wires and glass parts such as lenses. Both heavy contamination and light films are removed effectively without damaging the surface of the parts to be cleaned.
Kaijo can supply 40 kHz nominal (38 kHz actual) transducers in immersible, bolt-on and tank-mounted configurations. The transducers are available in 600 W and 1200 W models and can withstand cleaning solution temperatures of up to 100 degrees Celsius. Kaijo has the ultrasonic cleaning technology and experience to help customers choose the transducers or ultrasonic cleaning solutions most appropriate for their applications. For a free consultation or quote on selecting the right ultrasonic cleaning system and transducer for your specific cleaning application call Kaijo at 408 675-5575 or email [email protected].Read More
July 19, 2016
Ultrasonic cleaning systems are made up of ultrasonic transducers, generators, and cleaning tanks. The transducers are submerged in the cleaning solution and take the electric signal from the generator to produce the cleaning action. As the electric ultrasonic frequency signal rises and falls, the transducer vibrates and generates compression waves in the cleaning solution. These compression waves produce the cavitation bubbles responsible for ultrasonic cleaning.
The immersion of the ultrasonic transducers in the cleaning solution can be carried out in two ways. The immersible transducers are self-contained, sealed units connected to the ultrasonic generators with a cable. They are placed in the tank containing the cleaning solution together with the object to be cleaned.
The bolt-on or mounted transducers are mounted at the bottom or on the sides of the cleaning tank. Systems with bolt-on or mounted transducers produce consistent cleaning results but changing a bolt-on or mounted transducer for one of with a different frequency takes more time than changing an immersible transducer.
Ultrasonic transducers must be resistant to erosion from the effects of the cavitation bubbles and must be able to operate submerged in cleaning solutions at high temperatures. Kaijo ultrasonic transducers are hermetically sealed in 316L stainless steel housing with a thick metal plate to transmit the sound waves to the cleaning liquid and avoid damage from cavitation over extended periods. The transducers can be used at temperatures of up to 100 degrees Centigrade for most transducers and up to 80 degrees Centigrade for the transducers operating at 1 MHz.
Immersible ultrasonic transducers are available at ratings of up to 1200 W and at frequencies of 26kHz, 38kHz, 78kHz, 100kHz, 130kHz and 160kHz. They can be connected to any Kaijo ultrasonic generator and can be placed in existing tanks. Their ease of use and flexibility makes them ideal for facilities that have a wide variety of ultrasonic cleaning requirements.
Operators can place the object to be cleaned in a tank with an appropriate cleaning solution and insert one or several transducers with the desired frequency. The transducers can be placed in the tank either horizontally or vertically and cleaning can be varied to ensure optimum performance for a particular object and for the contamination to be removed or the type of cleaning required.
Bolt-on or Mounted Transducers
Bolt-on or Mounted ultrasonic transducers are available at ratings of up to 1200 W and at frequencies of 26kHz, 38kHz, 78kHz, 100kHz, 130kHz, 160kHz, 200kHz, 430kHz, 750kHz, and 950kHz. They are mounted at the bottom or on the sides of cleaning tanks or can be bolted onto the desired location on existing tanks. Kaijo ultrasonic transducers are compatible with the Kaijo Quava, Phenix Legend and Phenix III generators and they are available installed on Kaijo ultrasonic baths and tanks.
Bolt-on or mounted transducers are especially suited for manufacturing and laboratory facilities that have clearly defined ultrasonic cleaning needs. Kaijo can recommend a configuration that delivers top cleaning performance for a particular application. Frequency, tank size and number of transducers can be optimized for the specific cleaning requirements and the fixed transducer installation can deliver consistent cleaning results.
Whether the immersible or the fixed bolt-on or mounted transducers are the best solution for a particular application, Kaijo can propose a custom solution that delivers the optimum level cleaning without the degradation over time that can occur with other piezoelectric systems. Call 408 675-5575 or email [email protected] for a free consultation or quote on using an ultrasonic cleaning system for your application.Read More