Probe Systems

Probe-type sonicators are able to deliver to the extraction medium up to 100-fold greater power than that of an ultrasonic bath, so that a better performance is expected. One main feature for the successful application of ultrasonic probes for many chemical processes is that the ultrasonic energy is not transferred through the liquid medium to the extraction vessel but introduced directly into the system (Figure 6). The ultrasonic probe consists of the following components:

• A generator which is the source of alternating electrical frequency (typically 20 kHz). The generator allows tuning to be carried out for optimum performance.

Figure 5 Schematic diagram of an ultrasonic bath.

Figure 6 Schematic diagram of a probe-type sonicator.

• Ability of the ultrasonic processor to be used in pulsed mode operation which allows the medium to cool between pulses of sonication.

• The upper horn element - a piece of titanium to which the detachable horn is attached, forming both the emitter or booster.

• A detachable horn, usually made of a titanium alloy, which allows the vibration of the fixed horn to be transmitted to a chemical system. Tip erosion can occur as a result of cavitation. Depending on the volume of sample to be irradiated a range of detachable horns can be used.

Despite the improved performance displayed by probe-type sonicators for solid-liquid extraction compared with cleaning baths, a series of problems can arise with the use of these sonicators. Volatile components can be lost due to the 'degassing' effect of the ultrasound power. Ultrasound irradiation by means of probes is accompanied by a large amount of heat generated during operation, hence some cooling of the sonication vessel is required.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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