1、Designation: E1620 97 (Reapproved 2012)Standard TerminologyRelating to Liquid Particles and Atomization1This standard is issued under the fixed designation E1620; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONThe transformation of bulk liquid into collections of discrete drops in sprays or mists is required formany processes includin
3、g combustion, spray drying, evaporative cooling, humidification, and spraycoating. Several techniques are commonly used to measure and characterize collections of drops asfound in sprays, and a substantial body of terminology has evolved to describe liquid drops, droppopulations, sprays, and spray d
4、evices, all of which are of interest to the users of liquid atomizers,spray instruments, and data. This terminology lists terms commonly encountered in the literature onliquid drops and sprays and provides definitions specific to the subject area.1. Scope1.1 In a broad sense, this terminology covers
5、 terminologyassociated with liquid particles dispersed in gas. The principalemphasis, however, is on particles produced by the process ofatomization.1.2 All terms, followed by their definitions, are arrangedalphabetically. In addition, the terminology contains severaltables wherein terms related to
6、specific subjects are segregatedand identified.1.3 Within the broad scope, the following specific catego-ries are included:1.3.1 Terms pertaining to the structure and condition ofindividual particles or groups of particles as observed in nature.1.3.2 Terms pertaining to the structure and condition o
7、findividual particles or groups of particles produced by anatomizing device.1.3.3 Terms pertaining to atomizing devices according tothe primary energy source responsible for spray development.(When more than one term is used for the same device or classof devices, the alternative term is followed by
8、 the preferredterm.) Definitions of the devices may refer to their construc-tion, operating principle, or distinctive spray characteristics.The atomizers, however, are not classified by their respectiveareas of application or end use. Moreover, the listed terms aregeneric and do not include brand na
9、mes, trademarks, orproprietary designations.1.3.4 Terms pertaining to statistical parameters involvingparticle measurement, particle size, and size distribution func-tions.1.3.5 Terms pertaining to instruments and test proceduresutilized in the characterization of liquid particles and sprays.1.4 The
10、 values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.2. Referenced Documents2.1 ASTM Standards:2D1356 Terminology Relating to Sampling and Analysis ofAtmospheresE799 Practice for Determining Data Criteria and Processingfor Liquid Drop S
11、ize Analysis3. Terminologyaerating nozzle, na device to atomize liquid for the purposeof aeration.DISCUSSIONAlthough this term is occasionally used to designatecertain types of airblast or internal mixing pneumatic atomizers, it isambiguous and is not recommended for describing the latter devices.ae
12、rodynamic diameter, nthe diameter of a hypotheticalsphere having a specific gravity of unity and the samesettling velocity as the actual particle.aerosol, na dispersion of solid particles or liquid particles, orboth, in gaseous media. D13561This terminology is under the jurisdiction ofASTM Committee
13、 E29 on Particleand Spray Characterization and is the direct responsibility of Subcommittee E29.02on Non-Sieving Methods.Current edition approved April 1, 2012. Published May 2012. Originallyapproved in 1994. Last previous edition approved in 2004 as E1620 97 (2004).DOI: 10.1520/E1620-97R12.2For ref
14、erenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, We
15、st Conshohocken, PA 19428-2959, United States.air assist nozzle, na pneumatic atomizer in which pressur-ized air is utilized to enhance the atomization produced bypressurized liquid. The air may be required only for part ofthe operating range (for example, low liquid flow rates).air atomizing nozzle
16、, nsee pneumatic atomizer.air blast nozzle, nsee airblast nozzle.airblast nozzle, na pneumatic atomizer that utilizes arelatively large volume of low-pressure air.DISCUSSIONThe term is occasionally used to designate the entireclass of pneumatic atomizers.aspirating nozzle, nsee siphon nozzle.atomiza
17、tion, nthe process of atomizing.atomize, vto transform bulk liquid or slurry into particles.atomizer, na device for atomizing.Berglund-Liu atomizer, na vibratory atomizer in which apiezoelectric transducer transmits high-frequency oscilla-tions to a liquid stream discharged through an orifice,creati
18、ng relatively uniform drops whose size is a function ofthe frequency of oscillation and the flow rate of the liquidthrough the orifice.blast nozzle, nsee pneumatic atomizer.breakup, nliquid disintegration that occurs during atomiza-tion.TABLE 1 Summary of Atomizer TermsPressure Atomizer (hydraulic a
19、tomizer, pressure atomizing nozzle, Lubbock nozzlepressure nozzle, single-fluid atomizer) variable orifice poppet nozzle (variable orifice pintle nozzle)cone atomizer (cone spray nozzle)hollow cone atomizer Pneumatic Atomizer (air atomizing nozzle, blast nozzle, gas atomizer, gas-solid cone atomizer
20、 (full cone nozzle) liquid nozzle, twin-fluid atomizer, two-fluid atomizer)deflector atomizer (flood nozzle, flooding nozzle) air assist nozzledual orifice nozzle (duple nozzle) airblast nozzle (air blast nozzle,duplex nozzle aerating nozzle)piloted airblast nozzle (simplex airblast nozzle)Fan Spray
21、 Atomizer: prefilming airblast nozzleeven spray atomizer (even flow atomizer)flat spray atomizer (flat jet atomizer) External Mixing Pneumatic AtomizerLaskin nozzleFog NozzleInternal Mixing Pneumatic AtomizerImpact Atomizer: (impingement atomizer): (aerating nozzle,pintle atomizer Nukiyama-Tanasawa
22、nozzle,splash cup atomizer effervescent atomizer)splash plate atomizerCentrifugal Atomizer (rotary atomizer, slinger)Impinging Jet Atomizer (impingement atomizer): rotary cup atomizer (spinning cup atomizer)doublet atomizer rotary disk atomizer (spinning disk atomizer)triplet atomizer rotary wheel a
23、tomizerPlain Jet Atomizer (orifice atomizer, plain orifice atomizer, single jet atomizer, Vibratory Atomizer (vibrative atomizer)straight stream nozzle) electromagnetic vibratory atomizersimplex nozzle piezoelectric vibratory atomizerSquare Spray Nozzle Berglund-Liu atomizersonic nozzleSwirl Atomize
24、r ultrasonic nozzleSwirl Chamber Atomizer (centrifugal pressure nozzle, swirl chamber vibrating needle atomizeratomizer) vibrating reed atomizerby-pass nozzle (bypass nozzle, flowback nozzle, recirculating nozzle, returnflow nozzle, spill nozzle, spill return nozzle, spillback nozzle) Electrostatic
25、Atomizerdual orifice nozzle (duplex nozzle)duplex nozzle Shear Coaxial Injectorsimplex nozzle swirl coaxial injectorvariable-area nozzleSiphon Nozzle (aspirating nozzle)Sonic Nozzle (sonic-whistle atomizer, ultrasonic nozzle)TABLE 2 Characteristic Particle Diameters and DistributionFunctionsAerodyna
26、mic DiameterArea (surface) Mean DiameterDNf,DLf,DAf,DVfDe Brouckere DiameterEquivalent Volume SphereDiameterEvaporative DiameterHerdan DiameterLinear (arithmetic) Mean DiameterLog Normal DistributionMean DiametersNormal DistributionNukiyama-Tanasawa DistributionRelative SpanRosin-Rammler Distributio
27、nSauter Mean DiameterSquare Root Normal DistributionStokes DiameterUpper Limit Log NormalDistributionVolume Mean DiameterE1620 97 (2012)2breakup length, nthe distance between the liquid dischargepoint of an atomizing device and the point where liquidbreakup commences.bypass nozzle, nsee by-pass nozz
28、le.by-pass nozzle, na swirl chamber atomizer containingby-pass orifice(s) or port(s) through which part of the inletliquid may be withdrawn from the swirl chamber andreturned to the supply tank or pressure pump suction. Thedischarge flow is modulated by controlling the pressure inthe bypass line, us
29、ing a valve in the line.cavitation, nthe formation of vapor-filled cavities in theinterior or on the solid boundaries of liquids in motion wherethe pressure is reduced to a critical value without a change inambient temperature.centrifugal atomizer, na device wherein a rotating solidsurface is the pr
30、imary source of energy utilized to produce aspray.DISCUSSIONAlternatively, an atomizer that rotates to distribute theliquid.centrifugal pressure nozzle, nsee swirl chamber atomizer.circumferential patternation, nmeasurements taken in acircumferential direction, showing the variation in liquidflux ab
31、out the nozzle axis.cloud, nany collection of particulate matter in the atmo-sphere dense enough to be perceptible to the eye, especiallya collection of water drops. D1356coalescence, nthe merging of two or more liquid particles toform a single liquid particle.concentration, nsee number density.cone
32、 atomizer, nan atomizer that produces a conical spraypattern.cone pattern, na diverging spray pattern that is nominallysymmetric about the nozzle axis and whose apex is locatedat or near the nozzle discharge orifice.cone spray nozzle, nsee cone atomizer.convolution, nthe combination of local measure
33、ments ofdrop size distribution and number density into equivalentline-of-sight values of drop size distribution and opticalextinction.DNf,DLf,DAf,DVf, ndiameters such that the cumulativenumber of particles, (N), length of diameter, (L), surfacearea, (A), or volume, (V), from zero diameter to thesere
34、spective diameters is the fraction, (f), of the correspondingsum for the total distribution.ExampleDV0.5is the volume median diameter; that is,50 % of the total volume of liquid is in drops of smallerdiameter and 50 % is in drops of larger diameter.deconvolution, na procedure by which line-of-sight
35、mea-surements of drop size distribution and optical extinction areconverted into local representations of the distribution andnumber density.DISCUSSIONFor sprays whose drop size distributions are axisym-metric in space, an Abel inversion procedure has been used to performthe deconvolution.3,4deflect
36、or atomizer, nan atomizer in which a liquid jetspreads out over a solid surface, forming a spray whoseshape depends upon the solid surface.dispersion, na system of particles distributed in a solid,liquid, or gas.dispersion, nthe spread of values of a frequency distributionabout an average (in statis
37、tics). (Quantitative measures ofdispersion include range, variance, standard deviation, meandeviation, and relative span.)doublet injector, nan impinging jet atomizer in which thereare two colliding liquid jets.drop, na single liquid particle having a generally spheroidalshape.droplet, nsee drop; al
38、so a small drop.dual orifice nozzle, na swirl chamber atomizer containing aprimary injector and a concentric annular secondary injector,each injector comprising a separate orifice and set oftangential slots. The nozzle is normally operated only withthe primary injector at low flow rates, with second
39、ary liquidintroduced at a specified pressure. (This definition applies todevices used in the gas turbine industry.)duple nozzle, nsee dual orifice nozzle.duplex nozzle, na swirl chamber atomizer comprising asingle discharge orifice and two sets of tangential slots, eachwith a separately controlled l
40、iquid supply. The smaller(primary) slots supply liquid at low flow rates, and both sets(primary and secondary) are utilized as flow increases.effervescent atomizer, nan internal mixing pneumatic atom-izer in which gas bubbles are dispersed in the liquid stream.electromagnetic vibratory atomizer, na
41、vibratory atomizerin which an electromagnetic transducer transmits high-frequency oscillations to the liquid.electrostatic atomizer, na device wherein an electric chargeis the primary source of energy utilized to produce a spray.emitting spray angle, nsee initial spray angle.equivalent volume sphere
42、 diameter, nthe diameter of ahypothetical sphere having the same volume as the actualparticle.even flow atomizer, nsee even spray atomizer.even spray atomizer, na fan spray atomizer that produces arelatively uniform band of liquid, usually by means ofinjection, through an elliptical orifice. (This d
43、efinition ap-plies to devices utilized in the agricultural industry.)3Hammond, D.C., “A Deconvolution Technique for Line-Of-Sight OpticalScattering Measurements in Axisymmetric Sprays,” Applied Optics, Vol 20, No. 3,February 1981, pp. 493499.4Yule, A.J., Ah Seng, C., Felton, P.G., Ungut, A., and Chi
44、gier, N.A., “A LaserTomographic Investigation of Liquid Fuel Sprays,” Eighteenth Symposium-International-on Combustion, Pittsburgh: The Combustion Institute, 1981, pp.15011510.E1620 97 (2012)3external mixing pneumatic atomizer, na pneumatic atom-izer in which pressurized gas is directed on a liquid
45、film orjet outside the nozzle, so as to form a spray.fan pattern, na spray pattern in which the liquid flux isconcentrated in a narrow oval or ellipse in a plane perpen-dicular to the spray axis.fan spray atomizer, na pressure atomizer that produces aflat sheet of liquid that collapses into particle
46、s. The angle orwidth of the sheet is controlled by the shape of a slot or ovaldischarge orifice, by an external deflector, or by impingingjets.flat jet atomizer, nsee flat spray atomizer.flat spray atomizer, na fan spray atomizer that produces aplanar spray pattern.DISCUSSIONIn agricultural applicat
47、ions, the spray patterns havetapered edges.flood nozzle, nsee deflector atomizer.flooding nozzle, nsee deflector atomizer.flowback nozzle, nsee by-pass nozzle.flux, nthe number of particles flowing through a given areaper unit time.flux-sensitive, na sampling process where the magnitudemeasured resp
48、onds to the flux of particles through thesampling region.flux size distribution, nthe size distribution of particlespassing through a sampling zone during a given interval oftime, wherein individual particles are counted and sized.DISCUSSIONFlux size distributions are typically obtained by collec-ti
49、on techniques or by optical instruments capable of sensing individualparticles in flight. Certain sampling methods may provide neither fluxsize distributions nor spatial size distributions.fog, na quiescent cloud near the earths surface.fog nozzle, na high capacity pressure atomizer that producesa dispersion of fine drops.full cone nozzle, nsee solid cone atomizer.full cone pattern, na cone pattern wherein the liquid isdistributed throughout the pattern.gas atomizer, nsee pneumatic atomizer.gas-liquid nozzle,
