All ultrasonic cleaning equipment requires essentially 2 component groups; the Ultrasonic Generator, and a plurality of Ultrasonic Transducers. 

The ultrasonic generator is responsible for converting the incoming power frequency  from 60hz to the frequency required by the ultrasonic transducers which are installed in the system, typically 25kHz, 40kHz or 80kHz.  The generator also increases the incoming voltage to match the requirements of the transducers.

The transducers are responsible for emitting sound waves into the cleaning fluid to produce cavitation, the process by which all ultrasonic cleaning systems remove contaminants from the parts being cleaned.  Transducers are commonly mounted externally to the tank bottom or sides, or inside of sealed stainless steel boxes called Submersible Transducer Packs which are mounted inside of the cleaning tank, on the bottom or side walls of the tank. 

2 types of transducers are used for ultrasonic cleaning equipment; magnetostrictive transducers, and piezoelectric transducers.  Magnetostrictive Transducers are essentialy electromagnets rapidly cycled on and off to produce an ultrasonic cleaning effect in the tank.  Piezoelectric Transducers utilize a crystal manufactured commonly of lead zirconate titanate which rapidly expand and contract with incoming cycles of electrical current, thereby created the ultrasonic cleaning effect in the tank.

Before the development of efficient piezoelectric transducers, all manufacturers of ultrasonic cleaning equipment utilized magnetostrictive transducers.   Today, over 95% of all ultrasonic cleaning system manufacturers utilize piezoelectric transducers in their equipment designs to improve electrical efficiency, and allow ultrasonic cleaning system operation at frequencies above 30kHz.  For more information on transducer types, and how they compare with one-another, see our Transducer Types page under the Ultrasonic College drop down menu above.

The importance of the ultrasonic generator in the system design cannot be understated.  The generator is a high-voltage, high-frequency device which must be carefully engineered to allow long-term reliability.  Sufficient cooling is a requirement to ensure that the amplifier in the system operates below critical temperatures.

Customers must also be aware of the "modulation ratio" of the ultrasonic cleaning system under consideration.  Modulation Ratio refers to the number of transducers which are powered by a single ultrasonic generator.  The lower the ratio, the less down time the system might face in the event of a failure.  For example, if a system includes a total of 48 transducers, and each generator powers 12 of the 48, a generator failure will lead to a 25% loss of power in the ultrasonic cleaning tank.  This system would have a 12:1 modulation ratio.  However, if each generator drives only 3 of the 48 transducers installed (modulation ratio of 3:1) a loss of only 6.25% will be encountered in the event of a generator malfunction, which would allow the system to still clean parts with no down-time.  All Zenith ultrasonic generators are modulated at 3:1.

Ultrasonic cleaning tanks also commonly include a stainless steel Work Rest Platform, which is pictured above directly over the ultrasonic submersible transducers.  These devices are designed to prevent baskets of parts from resting directly on the ultrasonic emitting surface, thereby preventing damage to the submersible packs.  Work rest platforms are designed specifically to be light-weight to prevent reduction in ultrasonic cleaning power.  Any object which is placed in an ultrasonic tank will absorb some or all of the emitted energy.  If the work rest frame were manufactured of heavy-gauge materials, or of plastic materials, much of the ultrasonic energy being emitted from the tank bottom would never reach the parts being cleaned.

Stainless steel baskets manufactured of wire cloth are also used in ultrasonic cleaning tanks.  Baskets must also be designed using materials which maximize the amount of ultrasonic energy reaching the parts being cleaned.  Generally, larger openings in the mesh are preferred over smaller sizes, as tight mesh tends to reduce ultrasonic power in the basket considerably more.  When designing a basket for an ultrasonic application, Zenith will always use the largest mesh available that will be able to support the parts being cleaned.

For additional information, click here.

Zenith Mfg. & Chemical Corp.
85 Oak St.
Norwood, NJ  07648-0412
800-432-SONIC (7664)
FAX: 201-768-6999
sales@zenith-ultrasonics.com