Applications and Advantages
- Rapid Mixing
- no added air
- Homogenous mixing
- Small sample mixing
- Fast contamination removal
- Low noise
- Easy Cleaning
- Low cost
- Plug and Play
- No added air bubble
- Safe to use
The device is suitable for developing and performing scientific research.
It has 20 kHz working frequency with adjustable power range between 0-200 W.
It operates in pulse mode and total duration of reaction is also adjustable. In addition, it is equipped with thermometer which is for regulating the temperature of the reaction chamber.
How the Ultrasonic Homogenizer Works
The ultrasonic power supply (generator) converts 50/60 Hz voltage to high frequency electrical energy. This alternating voltage is applied to disc-shaped ceramic piezoelectric crystals within the converter, causing them to expand and contract with each change of polarity.
These longitudinal vibrations are amplified by the probe (horn) and transmitted into the liquid as ultrasonic waves consisting of alternate expansions and compressions. The pressure fluctuations pull the liquid molecules apart creating micro-bubbles (cavities), which expand during the negative pressure excursions, and implode violently during the positive excursions.
As the bubbles collapse, millions of shock waves eddies and extremes in pressures and temperatures are generated at the implosion sites. Although this phenomenon, known as cavitation, lasts but a few microseconds, and the amount of energy released by each individual bubble is minimal, the cumulative amount of energy generated is extremely high.
The high shear energy delivered is at maximum near the tip of the probe, and decreases as the distance away from the tip increases.
Compared to mechanical homogenizers, ultrasonic processing is fast and highly reproducible.
Probes are practically self cleaning, and by virtue of their design, account for negligible sample losses. When used with environmentally safe aqueous cleaning solutions, the Homogenizer becomes a powerful cleaning tool, capable of removing the most tenacious contaminants from normally inaccessible locations. Unlike ultrasonic baths, which dissipate the vibrational energy over a large area, the Homogenizer probe focuses the energy to create a concentrated, high intensity cleaning zone.
Probes (sometimes referred to as horns) are one-half wavelength long tools that act as mechanical transformers to increase the amplitude of vibration generated by the converter. They consist of two sections each having different cross-sectional areas. When driven at its resonant frequency, the probe expands and contracts longitudinally about its center. However, no longitudinal motion occurs at the threaded nodal point (area of no activity), allowing accessories to be connected to the probe at that point. The greater the mass ratio between the upper section and the lower section, the greater the amplification factor.
Probes with smaller tip diameters produce greater intensity of cavitation, but the energy released is restricted to a narrower, more concentrated field. Conversely, probes with larger tip diameters produce less intensity, but the energy is released over a greater area. The larger the tip diameter, the larger the volume that can be processed, but at lower intensity. High gain probes produce higher intensity than standard probes of the same diameter, and are usually recommended for processing larger volumes or difficult applications. Probes are fabricated from high grade titanium alloy Ti-6Al-4V because of its high tensile strength, good acoustical properties at ultrasonic frequencies, high resistance to corrosion, low toxicity, and excellent resistance to cavitation erosion. They are autoclavable, and available with threaded ends to accept replaceable tips, microtips and extenders.
Transducer is the main part in ultrasonic apparatus. Piezo ceramic rings existed in transducer convert electrical force into mechanical one in form of vibrations with high frequency. A transducer comprise of three major parts: backing, piezo ceramic rings and matching.
Even though ultrasonic vibrations are above the human audible range, ultrasonic processing produces a high pitched noise in the form of harmonics which emanate from the vessel walls and the fluid surface. The sound abating enclosure is made through metal sheets and insulated by means of elastomeric foams to damp and reduce annoying noises. It permits extended processing without discomfort by reducing the sound by 35db. There is a moveable table to adjust the height of probe in solution. Its approximate dimensions are 45×33×30 cm.