1、Designation: E 1620 97 (Reapproved 2004)Standard TerminologyRelating to Liquid Particles and Atomization1This standard is issued under the fixed designation E 1620; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 inclu
3、ding 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 spra
4、y devices, 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 cov
5、ers 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
6、to 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 conditio
7、n ofindividual 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
8、 by 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
9、 names, 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.2. R
10、eferenced Documents2.1 ASTM Standards:2D 1356 Terminology Relating to Sampling and Analysis ofAtmospheresE 799 Practice for Determining Data Criteria and Process-ing for Liquid Drop Size Analysis3. Terminologyaerating nozzlea device to atomize liquid for the purpose ofaeration.NOTE 1Although this te
11、rm is occasionally used to designate certaintypes of airblast or internal mixing pneumatic atomizers, it is ambiguousand is not recommended for describing the latter devices.aerodynamic diameterthe diameter of a hypotheticalsphere having a specific gravity of unity and the samesettling velocity as t
12、he actual particle.aerosol, na dispersion of solid particles or liquid particles, orboth, in gaseous media. (D 1356)air assist nozzlea pneumatic atomizer in which pressurizedair is utilized to enhance the atomization produced bypressurized liquid. The air may be required only for part ofthe operatin
13、g range (for example, low liquid flow rates).air atomizing nozzlesee pneumatic atomizer.air blast nozzlesee airblast nozzle.airblast nozzlea pneumatic atomizer that utilizes a relativelylarge volume of low-pressure air.1This terminology is under the jurisdiction of ASTM Committee E29 on Particleand
14、Spray Characterization and is the direct responsibility of Subcommittee E 29.04on Liquid Particle Measurement.Current edition approved May 1, 2004. Published May 2004. Originallyapproved in 1994. Last previous edition approved in 1997 as E 1620 97.2For referenced ASTM standards, visit the ASTM websi
15、te, 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, West Conshohocken, PA 19428-2959, United State
16、s.NOTE 2The term is occasionally used to designate the entire class ofpneumatic atomizers.aspirating nozzlesee siphon nozzle.atomization, nthe process of atomizing.atomize, vto transform bulk liquid or slurry into particles.atomizer, na device for atomizing.Berglund-Liu atomizera vibratory atomizer
17、in which apiezoelectric transducer transmits high-frequency oscilla-tions to a liquid stream discharged through an orifice,creating relatively uniform drops whose size is a function ofthe frequency of oscillation and the flow rate of the liquidthrough the orifice.blast nozzlesee pneumatic atomizer.b
18、reakup, nliquid disintegration that occurs during atomiza-tion.breakup length, nthe distance between the liquid dischargepoint of an atomizing device and the point where liquidbreakup commences.bypass nozzlesee by-pass nozzle.by-pass nozzlea swirl chamber atomizer containing by-passorifice(s) or por
19、t(s) through which part of the inlet liquidmay be withdrawn from the swirl chamber and returned tothe supply tank or pressure pump suction. The dischargeflow is modulated by controlling the pressure in the bypassline, using a valve in the line.cavitation, nthe formation of vapor-filled cavities in t
20、heinterior or on the solid boundaries of liquids in motion whereTABLE 1 Summary of Atomizer TermsPressure Atomizer (hydraulic atomizer, pressure atomizing nozzle, Lubbock nozzlepressure nozzle, single-fluid atomizer) variable orifice poppet nozzle (variable orifice pintle nozzle)cone atomizer (cone
21、spray nozzle)hollow cone atomizer Pneumatic Atomizer (air atomizing nozzle, blast nozzle, gas atomizer, gas-solid cone atomizer (full cone nozzle) liquid nozzle, twin-fluid atomizer, two-fluid atomizer)deflector atomizer (flood nozzle, flooding nozzle) air assist nozzledual orifice nozzle (duple noz
22、zle) airblast nozzle (air blast nozzle,duplex nozzle aerating nozzle)piloted airblast nozzle (simplex airblast nozzle)Fan Spray Atomizer: prefilming airblast nozzleeven spray atomizer (even flow atomizer)flat spray atomizer (flat jet atomizer) External Mixing Pneumatic AtomizerLaskin nozzleFog Nozzl
23、eInternal Mixing Pneumatic AtomizerImpact Atomizer: (impingement atomizer): (aerating nozzle,pintle atomizer Nukiyama-Tanasawa nozzle,splash cup atomizer effervescent atomizer)splash plate atomizerCentrifugal Atomizer (rotary atomizer, slinger)Impinging Jet Atomizer (impingement atomizer): rotary cu
24、p atomizer (spinning cup atomizer)doublet atomizer rotary disk atomizer (spinning disk atomizer)triplet atomizer rotary wheel atomizerPlain Jet Atomizer (orifice atomizer, plain orifice atomizer, single jet atomizer, Vibratory Atomizer (vibrative atomizer)straight stream nozzle) electromagnetic vibr
25、atory atomizersimplex nozzle piezoelectric vibratory atomizerSquare Spray Nozzle Berglund-Liu atomizersonic nozzleSwirl Atomizer ultrasonic nozzleSwirl Chamber Atomizer (centrifugal pressure nozzle, swirl chamber vibrating needle atomizeratomizer) vibrating reed atomizerby-pass nozzle (bypass nozzle
26、, flowback nozzle, recirculating nozzle, returnflow nozzle, spill nozzle, spill return nozzle, spillback nozzle) Electrostatic Atomizerdual orifice nozzle (duplex nozzle)duplex nozzle Shear Coaxial Injectorsimplex nozzle swirl coaxial injectorvariable-area nozzleSiphon Nozzle (aspirating nozzle)Soni
27、c Nozzle (sonic-whistle atomizer, ultrasonic nozzle)TABLE 2 Characteristic Particle Diameters and DistributionFunctionsAerodynamic DiameterArea (surface) Mean DiameterDNf,DLf,DAf,DVfDe Brouckere DiameterEquivalent Volume SphereDiameterEvaporative DiameterHerdan DiameterLinear (arithmetic) Mean Diame
28、terLog Normal DistributionMean DiametersNormal DistributionNukiyama-Tanasawa DistributionRelative SpanRosin-Rammler DistributionSauter Mean DiameterSquare Root Normal DistributionStokes DiameterUpper Limit Log NormalDistributionVolume Mean DiameterE 1620 97 (2004)2the pressure is reduced to a critic
29、al value without a change inambient temperature.centrifugal atomizera device wherein a rotating solidsurface is the primary source of energy utilized to produce aspray.NOTE 3Alternatively, an atomizer that rotates to distribute the liquid.centrifugal pressure nozzlesee swirl chamber atomizer.circumf
30、erential patternation, nmeasurements taken in acircumferential direction, showing the variation in liquidflux about 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. (D 1356)coalescence, n
31、the merging of two or more liquid particles toform a single liquid particle.concentrationsee number density.cone atomizeran 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
32、nozzle discharge orifice.cone spray nozzlesee cone atomizer.convolutionthe combination of local measurements of dropsize distribution and number density into equivalent line-of-sight values of drop size distribution and optical extinction.DNf,DLf,DAf,DVfdiameters such that the cumulative num-ber of
33、particles, (N), length of diameter, (L), surface area,(A), or volume, (V), from zero diameter to these respectivediameters is the fraction, (f), of the corresponding sum forthe total distribution.Example:DV0.5is the volume median diameter; that is, 50 % of thetotal volume of liquid is in drops of sm
34、aller diameter and 50 %is in drops of larger diameter.deconvolutiona procedure by which line-of-sight measure-ments of drop size distribution and optical extinction areconverted into local representations of the distribution andnumber density.DISCUSSIONFor sprays whose drop size distributions are ax
35、isym-metric in space, an Abel inversion procedure has been used to performthe deconvolution.3deflector atomizeran atomizer in which a liquid jet spreadsout over a solid surface, forming a spray whose shapedepends upon the solid surface.dispersion, na system of particles distributed in a solid,liquid
36、, or gas.dispersion, nthe spread of values of a frequency distributionabout an average (in statistics). (Quantitative measures ofdispersion include range, variance, standard deviation, meandeviation, and relative span.)doublet injectoran impinging jet atomizer in which thereare two colliding liquid
37、jets.drop, na single liquid particle having a generally spheroidalshape.droplet, nsee drop; also a small drop.dual orifice nozzlea swirl chamber atomizer containing aprimary injector and a concentric annular secondary injector,each injector comprising a separate orifice and set oftangential slots. T
38、he nozzle is normally operated only withthe primary injector at low flow rates, with secondary liquidintroduced at a specified pressure. (This definition applies todevices used in the gas turbine industry.)duple nozzlesee dual orifice nozzle.duplex nozzlea swirl chamber atomizer comprising a singled
39、ischarge orifice and two sets of tangential slots, each witha separately controlled liquid supply. The smaller (primary)slots supply liquid at low flow rates, and both sets (primaryand secondary) are utilized as flow increases.effervescent atomizeran internal mixing pneumatic atom-izer in which gas
40、bubbles are dispersed in the liquid stream.electromagnetic vibratory atomizera vibratory atomizer inwhich an electromagnetic transducer transmits high-frequency oscillations to the liquid.electrostatic atomizera device wherein an electric charge isthe primary source of energy utilized to produce a s
41、pray.emitting spray angle, nsee initial spray angle.equivalent volume sphere diameterthe diameter of a hy-pothetical sphere having the same volume as the actualparticle.even flow atomizersee even spray atomizer.even spray atomizera fan spray atomizer that produces arelatively uniform band of liquid,
42、 usually by means ofinjection, through an elliptical orifice. (This definition ap-plies to devices utilized in the agricultural industry.)external mixing pneumatic atomizera pneumatic atomizerin which pressurized gas is directed on a liquid film or jetoutside the nozzle, so as to form a spray.fan pa
43、ttern, 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 atomizera pressure atomizer that produces a flatsheet of liquid that collapses into particles. The angle orwidth of the sheet is controlled by the shape o
44、f a slot or ovaldischarge orifice, by an external deflector, or by impingingjets.flat jet atomizersee flat spray atomizer.flat spray atomizera fan spray atomizer that produces aplanar spray pattern.NOTE 4In agricultural applications, the spray patterns have taperededges.flood nozzlesee deflector ato
45、mizer.flooding nozzlesee deflector atomizer.flowback nozzlesee by-pass nozzle.fluxthe number of particles flowing through a given area perunit time.flux-sensitivea sampling process where the magnitude mea-sured responds to the flux of particles through the samplingregion.3Hammond, D. C., “A Deconvol
46、ution Technique for Line-Of-Sight OpticalScattering Measurements in Axisymmetric Sprays,” Applied Optics, Vol 20, Number3, February 1981, pp 493499; Yule, A. J., Ah Seng, C., Felton, P. G., Ungut, A., andChigier, N. A., “A Laser Tomographic Investigation of Liquid Fuel Sprays,”Eighteenth Symposium-I
47、nternational-on Combustion, Pittsburgh: The CombustionInstitute, 1981, pp 15011510.E 1620 97 (2004)3flux size distributionthe size distribution of particles pass-ing through a sampling zone during a given interval of time,wherein individual particles are counted and sized.DISCUSSIONFlux size distrib
48、utions are typically obtained by collec-tion 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 nozzlea high capa
49、city pressure atomizer that produces adispersion of fine drops.full cone nozzlesee solid cone atomizer.full cone pattern, na cone pattern wherein the liquid isdistributed throughout the pattern.gas atomizersee pneumatic atomizer.gas-liquid nozzlesee pneumatic atomizer.globalindicates measurements or observations of a totaldispersion of particles (such as, a sample representative of anentire liquid spray).hollow cone atomizera cone atomizer wherein most of theliquid is directed toward the outside of the spray
