Ultrasonic Ballast Water Disinfection by ultrasonic treatment system

Ultrasonic Ballast Water Disinfection by ultrasonic treatment system

Parameter

Introduction:

Ultrasonic Ballast Water Disinfection The ultrasonic treatment system

Ultrasonic Ballast Water Treatment Marine fouling organisms can be divided into the following three categories

• Soft growths such as sponges;
• Bacteria and single-cell organic matter, such as various types of bacteria and algae;
• Hard marine animals, such as barnacles, bivalve molluscs, etc.

Sound
Sound can be described as mechanical energy transmitted by pressure waves in a material medium. Thus, sound can be described as a form of energy or a sound is said to be mechanical. This distinguishes sound energy form other forms of energy, such as electromagnetic energy. This general definition encompasses all types of sound, including audible sound, low-frequency seismic waves (infrasound), and ultrasound.

Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Although this limit varies from person to person, it is approximately 20 kilohertz (20,000 hertz) in healthy, young adults and thus, 20 kHz serves as a useful lower limit in describing ultrasound.

Ultrasound Applications
Current applications of ultrasound includes for example: sonochemistry (emulsification, acceleration of chemical reactions, extraction etc.) dispersion, and disruption of biological cells (ultrasonic disintegration), removal of trapped gases, cleaning of microscopic contamination, ultrasonic humidifier, ultrasound identification (USID), and typically to penetrate a medium and measure the reflection signature or supply focused energy. The reflection signature can reveal details about the inner structure of the medium. The most well known application of this technique is its use in sonography to produce pictures of fetuses in the human womb. Other application is using ultrasound in cancer diagnose.

The numbers of ultrasound application is numerous. Combining the right frequencies, the right amplitude and using the right transducer numerous types of ultrasound application can be achieved… ‘The Sky Is The Limit’…

Ultrasound Forces
Exposing liquids to high mechanical pressure waves (or sound waves), forces as acoustical streaming, stable cavitation and transient (unstable or inertial) cavitation can be induced.

For example ultrasonic disintegration, sonochemistry and sonoluminescence arises from acoustic cavitation: the formation, growth, and implosive collapse of bubbles in a liquid. Cavitational collapse produces intense local heating (~5000 K), high pressures (~1000 atm), and enormous heating and cooling rates (>10 9 K/sec). Acoustic cavitation provides a unique interaction of energy and matter, and ultrasonic irradiation of liquids causes high energy chemical reactions to occur, often accompanied by the emission of light.

This can only be achieved in specific situation involving specific frequencies of high ultrasound power (high W•cm-2, high dB) exposed to relatively low liquid volumes of relatively low temperatures.