Sonication energy

Other types are available that use sonic energy (from gas streams), ultrasonic energy (electronic), and electrostatic energy, but they are less commonly used in process industries. See Table 14-11 for a sum-maiy of the advantages/disadvantages of the different type units. An expanded discussion is given by Masters [Spray Drying Handbook, Wiley, New York, (1991)]. 

On the other hand, RPBs suffer from poor heat transfer possibilities. Heat input could theoretically be achieved by use of eddy currents, microwaves, or sonic energy, and thus endothermic reactions are, in principle, possible. The heat removal is more problematic and exothermic reactions must be conducted adiabatically within the rotor. Alternating packing and heat transfer plates could perhaps be an option, although it would greatly increase the complexity and the price of the reactor. 

The result is an intense field of sonic energy focused between the nozzle body and... 

J.P. Russell and M. Smith, Sonic energy in processing use of a large scale, low frequency sonic reactor, Advances in Sonochemistry, T.J. Mason (ed.), JAI Press, 1999, 5, 175-208, ISBN 0-7623-0331-X. 

Industrially, the silver is recovered from either the wash water, or the bleach fix separately or from a mixture of the two using electrolysis employing a stainless steel cathode cylinder and an anode of stainless steel mesh. A typical wash solution composition contains silver (4 g L ), sodium thiosulphate (220 g L ), sodium bisulphite (22 g L ) and sodium ferric EDTA (4 g L ). At Coventry we have used a scaled down version of the industrial process employing 250 mL samples [46]. Electrolysis experiments were performed at ambient temperature with both wash and bleach fix solutions and in which the potential applied to the cathode and the speed of rotation of the cathode were varied. The sonic energy (30 W) was supplied by a 38 kHz bath. The results are given in Tab. 6.9. The table shows that the recovery of silver on sonication of the wash or bleach fix solutions is much improved especially if the electrode is rotated while ultrasound is applied. Yields with bleach fix (which contains ferric ions) are less since Fe and Ag compete for discharge (Eqs. 6.13 and 6.14). 

J.P. Russell and M. Smith, Sonic energy in processing Use of a large scale,... 

Figure 7. Release profile from sonicated capsules. Samples that were to be treated with sonic energy were placed in the polypropylene cages and immersed in 10 ml of physiological saline in scintillation vials. The vials were subjected to 3 minutes of sonication at 4 C in a sonic bath. The capsules were then transferred to fresh buffer and the release of myoglobin was followed (- -) and compared with release from capsules containing free myoglobin (-x-).

The attenuation of sonic energy by absorption is an exponential function of the pathlength, x, and the absorbance, a ... 

Hartmann whistles have also found application in process technology by utilization of the sonic energy for the dispersal of liquids. So-called Liquid whistles serve to produce emulsions and dispersions. A high pressure flat jet of liquid impinges on the edge of a thin blade. Such devices have been used to produce insecticide emulsions, and also, probably, dispersions of other agents... 

Neumann, E.P. and Norton, J.L., "Application of Sonic Energy to Commercial Aerosol Collection Problems", Chemical Engineering Symposium Series No. 1, Vol. 47, 4 -10 (1951). 

Cool the flask to 0°C and start sonication, while adjusting the sonication energy level to the minimum giving the cavitation noise.b... 

In order to understand this phenomenon, let us consider briefly the anatomical pathways by which sonic energy is perceived. The auditory system can be conveniently divided into two components the peripheral portion consisting of the external, middle and inner ears (Figure 1) and the central portion, comprising of the auditory nerve and pathways to various central neural structures (Figure 2). 

Heat sealing is usually applied to the joining of pliable plastics sheet (less than 50 mils thick) and is limited to use on thermoplastic materials. The heat may be provided by thermal, electrical, or sonic energy. A wide variety of heat sealing systems are available. 

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