The Structure Of Ultrasonic Cleaner
The structure of ultrasonic cleaning machine
Today we will talk about the structure of ultrasonic cleaner.All the ultrasonic cleaning system have many components,it is a difficult things that we learn about all the components and may be you will lose your patience to continue reading.So,we just list three main components we want to introduce–1.ultrasonic cleaning bath or tank 2.ultrasonic transducer 3.ultrasonic generator
1.Ultrasonic cleaning bath or tank
It is used to fill with liquid like water or any solution and mixing with the items you want to clean. there are many different size to fit your items such as 3L, 6L ,10L ,30L and may be have larger capacity in the professional cleaning field
in general, the ultrasonic cleaning tank is made of sus 304 stainless steel
Type 304 is the most versatile and widely used stainless steel. most people still sometimes referred to its old name 18/8 ,because its main chemical components including 18% chromium and 8% nickel.
type sus 304 has many features:
1.its Antirust performance is better than 302 stainless steel materials and have a high temperature resistance.
2.304 has excellent corrosion resistance in a wide variety of environments and when in contact with different corrosive media.
3.it also has good resistance to oxidation in intermittent service up to 870°C and in continuous service to 925°C.
so,304 sus staninless steel is widely applied in many kinds of fields
304 stainless steel is typically used in:
- Sinks and splashbacks
- Cutlery and flatware
- Architectural panelling
- Sanitaryware and troughs
- Brewery, dairy, food and pharmaceutical production equipment
- Springs, nuts, bolts and screws
- Medical implantS
Typical chemical composition
|%||SUS Stainless steel 304|
Typical Physical Properties
|Modulus of Elasticity||193 Gpa|
|Electrical Resistivity||0.072×10-6 Ω.m|
|Thermal Conductivity||16.2 W/m.K at 100°C|
|Thermal Expansion||17.2×10-6 /K at 100°C|
Typical Mechanical Properties
|Compression Strength (MPa)||210|
|Proof Stress 0.2% (MPa)||210|
|Elongation A5 (%)||45|
|Hardness Rockwell B||92|
An ultrasonic transducer is a device that converts electric energy into mechanical energy.
It take a signal in one form (electrical) and convert it into a signal of
another form (a sound wave, which also may be expressed as a acoustics pulse or pressure wave).
So,the function of the transducer used in ultrasonic cleaning is to convert the electrical pulses from the generator into a sound wave or pressure wave. When this sound wave/pressure wave is driven through a liquid with appropriate amplitude it will cause the formation of a cavitation vapor/vacuum cavity,which is the scrubbing force found in ultrasonic cleaning systems.
There two varieties transducers available, MAGNETO STRICTIVE and ELECTROI STRICTIVE.
1) The magnetostrictive type transducers contain ferromagnetic nickel laminations surrounded by electrical coils.
During operation a varying magnetic field causes the laminations to alternately expand and contract
generating a sound wave or pressure wave that is driven into the liquid of an ultrasonic tank.
Magnetrostrictive transducers are a low frequency transducer and cannot operate practically at frequencies
higher than approximately 20 KHz. Magnetostrictive transducers can lose up to 50 % of their applied
energy in the form of heat making it difficult to maintain a low temperature in the ultrasonic bath.
Magnetostrictive transducers are a low voltage, high current device that requires polarization. Do to the
low operating frequency sub harmonics from the fundamental frequency are at a high amplitude in the
human hearing range and usually will require ear protection by operating personal or other precautions will have to be taken.
2) Electrostrictive (piezoelectric) transducers have ceramic crystals, which similarly expand, and contract
(vibrate) in a varying electrical field. First quartz was used, then barium titanate. The draw back with the
quartz was the high cost. The draw back with the barium titanate was the low operating temperature of 160
degrees Fahrenheit (70 Celsius) maximum, or the transducer would become de polarized and destroyed.
The new lead zerconate titanate ceramic transducer element can withstand temperatures in excess of 250
degrees Fahrenheit (120 Celsius). These piezoelectric transducers are a high voltage low current device and are far more efficient in energy conversion (in excess of 90 %). The piezoelectric ceramic can be
manufactured to virtually any operating frequency making in the most widely used material used for
ultrasonic applications. The transducer ceramic crystal is compressed into a “sandwich ” consisting of a
steel back plate and a steel or aluminum face plate for protecting the fragile ceramic, to aid in mounting to
the tank wall, and to adjust the fundamental frequency by compression forces of the sandwich assembly.
The advantages of ceramic technology in stacking ultrasonic transducers within the sandwich are
overwhelming. Silicon carbide, second only to diamonds in hardness and acoustically the best ceramic in
the world to transmit a sound wave should be used to enhance the transmission of ultrasonic sound wave
from the transducer sandwich assembly.
Ultrasonic generators are the power source for providing electrical power to the transducer at the voltage required for operation. Each generator is designed to drive a designated number of transducers.
Ultrasonic generator can produce a specific frequency signal, this signal can be a sine signal or pulse signal, this particular frequency is also for the ultrasonic transducer.In general, the ultrasonic frequency is 25 KHZ, 28 KHZ, 35 KHZ, 40 KHZ; 100 KHZ.