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(analytical chemistry)
In flame spectrometry, conversion of a volatilized sample into free atoms.
A process in which the chemical bonds in a molecule are broken to yield separated (free) atoms.
(mechanical engineering)
The mechanical subdivision of a bulk liquid or meltable solid, such as certain metals, to produce drops, which vary in diameter depending on the process from under 10 to over 1000 micrometers.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


The process whereby a bulk liquid is transformed into a multiplicity of small drops. This transformation, often called primary atomization, proceeds through the formation of disturbances on the surface of the bulk liquid, followed by their amplification due to energy and momentum transfer from the surrounding gas.

Spray formation processes are critical to the performance of a number of technologies and applications. These include combustion systems (gas turbine engines, internal combustion engines, incinerators, furnaces, rocket motors), agriculture (pesticide and fertilizer treatments), paints and coatings (furniture, automobiles), consumer products (cleaners, personal care products), fire suppression systems, spray cooling (materials processing, computer chip cooling), medicinal (pharmaceutical), and spray drying (foods, drugs, materials processing). Current concerns include how to make smaller drops (especially for internal combustion engines), how to make larger drops (agricultural sprays), how to reduce the number of largest and smallest drops (paints and coatings, consumer products, medicinals, spray drying), how to distribute the liquid mass more uniformly throughout the spray, and how to increase the fraction of liquid that impacts a target (paints and coatings, spray cooling, fire suppression).

Spray devices (that is, atomizers) are often characterized by how disturbances form. The most general distinction is between systems where one or two fluids flow through the atomizer. The most common types of single‐fluid atomizers are pressure (also called plain‐orifice, hydraulic, or pneumatic), pressure‐swirl, rotary, ultrasonic (sometimes termed whistle or acoustic), and electrostatic. Twin‐fluid atomizers include internal‐mix and external‐mix versions, where these terms describe the location where atomizing fluid (almost always a gas) first contacts fluid to be sprayed (almost always a liquid).

While primary atomization is important, because of its role in determining mean drop size and the spectrum of drop sizes, subsequent processes also play key roles in spray behavior. They include further drop breakup (termed secondary atomization), drop transport to and impact on a target, drop evaporation (and perhaps combustion), plus drop collisions and coalescence. In addition, the spray interacts with its surroundings, being modified by the adjacent gas flow and modifying it in turn. See Particulates

McGraw-Hill Concise Encyclopedia of Engineering. © 2002 by The McGraw-Hill Companies, Inc.


The formation of tiny droplets or a very fine spray, as produced by impinging jets of air on a small stream of paint in spray painting.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
The dynamics of spray atomisation have never been easier to understand.
The new gun improves paint atomisation, transfer efficiency, durability and operator comfort with greatly simplified controls that allow the operator to independently adjust the spray fan pattern, fluid flow and the electrostatic effect "on the gun" to give the best possible spray finish, and transfer efficiencies.
Ransburg have reinvented the electrostatic spray gun by significantly improving paint atomisation, transfer efficiency, durability and operator comfort with greatly simplified controls.
Compact's spray performance is achieved with the utilisation of the very latest cutting edge atomisation technology.
Collaboration between Hosokawa Micron Ltd and Novel Technical Solutions Ltd has led to the development of atomisation technology which revolutionises the production of microfine powders.
The choice of accessories provides the finest atomisation and control over many pattern sizes and allows the use of a range of paints including those with up to 70 per cent solids.
The AA1500 and AA4000 guns operate at 1500 or 4000 psi respectively to produce quality 'low overspray' atomisation, they are extremely lightweight with many built-in ergonomic features such as lower trigger pull tension and decreased trigger travel which results in reduced operator fatigue and RSi.
This is because of both their light weight and the excellent atomisation achieved with water-bome coatings."