Ultrasonic cleaning system

Commercial and custom-made ultrasonic cleaning systems... 

Burstein [57] has given several examples of aqueous ultrasonic cleaning systems that can remove ... 

Four-station ultrasonic cleaning system using aqueous and semi-aqueous chemistries... 

All ultrasonic cleaning systems consist of the four fundamental components of... 

Anonymous, Multi stage ultrasonic cleaning system for the metal, electronics, aerospace and allied industries. Lubr. Eng. 52, 669-669 (1996)... 

Layton Technologies developed ultrasonic cleaning system for aerospace company facing stringent environmental regulations." The system meets California regulations, saves 60% solvent, and has full carbon adsorption." ... 

Lamminen MO, Walker HW, Weavers LK (2006) Cleaning of particle-fouled membranes during cross-flow filtration using an embedded ultrasonic transducer system. J Membrane Sci 283 225-232... 

Fig. 7. The impingement of this jet can create a localized erosion (and even melting) responsible for surface pitting and ultrasonic cleaning (68-70). A second contribution to erosion created by cavitation involves the impact of shock waves generated by cavitational collapse. The magnitude of such shock waves can be as high as 104 atmospheres, which will easily produce plastic deformation of malleable metals (77). The relative magnitudes of these two effects depends heavily on the specific system under consideration.

In cases where low intensity irradiation is needed batch treatment could be as simple as using a large-scale ultrasonic cleaning bath as the reaction vessel. However the tank would need to be constructed of a material which was inert towards the chemicals involved. An appropriate grade of stainless steel might prove adequate or plastic tanks could be used. In the latter case however the transducer would need to be bonded onto a stainless or titanium plate and this assembly then bolted to the tank. A useful variant to this and indeed one which offers greater flexibility in use is the sealed, submersible transducer assembly (Fig. 7.17). With either system some form of additional (mechanical) stirring would almost certainly be needed. 

Of the four types of laboratory ultrasonic apparatus commercially available for practising chemists in general (namely, whistle reactors, ultrasonic cleaning baths, probes and cup-horn devices) analytical chemists, except for a few specialists working in (or with) ultrasound detectors, use mainly cleaning baths and probes both of which are usually operated at a fixed frequency dependent on the particular type of transducer, that is usually 20 kHz for common probe systems and 40 kHz for baths. Both types of devices are described below. 

In the process of sonication, electrical energy is converted into mechanical energy. The sound waves produce cavitation (the process of formation and collapse of microscopic bubbles) which leads to great mechanical shear forces. Particles are hammered to form smaller particles, and the increased energy of the system can promote chemical reactions. Ultrasonic chemistry has recently been reviewed [34]. Most research in sonichemistry has been carried out in ultrasonic cleaning baths. Operations on scale can be carried out by using commercial flow cells [35],... 

Three basic schemes for the ultrasonic cleaning of the melt can be proposed (1) in a liquid bath of an ingot (the melt surface is in a contact with a waveguide-radiating ultrasonic system) (2) in a mold (oscillations transmit to the melt through mold walls) and (3) in an intermediate vessel placed in the flow of melt from a holding furnace to a mold (oscillations transmits to the melt according to the first scheme). 

Easy to use, long-tank life, alkaline aqueous cleaner designed for batch washers Easy to use, low pH aqueous cleaning solution for ultrasonic immersion cleaning systems... 

Spray batch and spray in-line cleaning systems for OA, no-clean, and RMA pastes and lead-free flux residues Removes all types of flux residues including lead-free in batch washing Flux residue removal in ultrasonic immersion cleaning systems requiring no sump side additives... 

Versatile ultrasonic precision cleaning system for aqueous or semi-aqueous processes with all-in-one rinse and dry operations... 

Microstreaming, shock waves, and liquid microjets in the vicinity of solid surfaces lead to very efficient cleaning. This effect has been used in industry for more than forty years. Insoluble layers of inorganic salts, polymers, or liquids can be removed by the ultrasonic cleaning effect. In heterogeneous systems such a clean reactive surface leads to improved dissolution rates of metals in acids and enhanced reaction rates. Chemical reactions giving insoluble products are freed from these mass-transport-limiting layers and react rapidly. 

A process that has found widespread use in practice is semi-aqueous cleaning with ZESTRON FA. This cleaner was especially developed for removal of no-clean soldering fluxes in ultrasonic batch or spray under immersion cleaning systems. It is used in the cleaning bath, rinsed with demineralized water, and then dried with hot air (see scheme in Figure 14.8.13.). 

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