1、Designation:D694119Standard Practice forMeasuring Fluidization Segregation Tendencies of Powders1This standard is issued under the fixed designation D6941;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A nu
2、mber in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This practice covers an apparatus and procedure forcreating several specimens of a powder sample that,if thepowder is one that segregates by
3、 the fluidization mechanism,should be different from one another.1.2 A powder sample is fluidized then,after the fluidizinggas is turned off,it is separated into three or more specimensthat can be analyzed for parameters of interest.The differencein these parameters between the specimens is an indic
4、ation ofthe segregation potential of the powder.1.3 Powders must be capable of being fluidized in order tobe tested by this practice.1.4 Temperature-and moisture-sensitive powders may needto be tested at different temperatures and moisture contents,aswould happen in an industrial environment.1.5 Thi
5、s standard is not applicable to all bulk solids andsegregation mechanisms:while fluidization is a commonsegregation mechanism experienced by many fine powders,other segregation mechanisms not evaluated by this standardmight induce segregation in practice.Practice D6940 coversanother common mechanism
6、:sifting.1.6 The extent to which segregation will occur in anindustrial situation is not only a function of the powder and itstendency to segregate,but also the handling equipment(forexample,bin design),process(for example,transfer rates),andenvironment.1.7 The values stated in SI units are to be re
7、garded asstandard.No other units of measurement are included in thisstandard.1.8 This practice offers a set of instructions for performingone or more specific operations.This document cannot replaceeducation or experience and should be used in conjunction withprofessional judgment.Not all aspects of
8、 this practice may beapplicable in all circumstances.This ASTM standard is notintended to represent or replace the standard of care by whichthe adequacy of a given professional service must be judged,nor should this document be applied without consideration ofa projects many unique aspects.The word
9、Standard in the titleof this document means only that the document has beenapproved through the ASTM consensus process.1.9 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate
10、 safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.10 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment
11、 of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD2216 Test Methods for Laboratory Determination of Water(Moistur
12、e)Content of Soil and Rock by MassD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD6940 Practice for Measuring Sifting Segregation Tenden-cies of Bulk Solids3.Terminology3.1 Definitions:3.1.1 For c
13、ommon definitions of technical terms in thisstandard,refer to Terminology D653.4.Summary of Practice4.1 Arepresentative sample of a powder is placed in the testchamber.4.2 Pressurized gas(usually air),which is blown from thebottom,is ramped up from zero to a pre-determined High1This practice is unde
14、r the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.24 on Characterizationand Handling of Powders and Bulk Solids.Current edition approved May 1,2019.Published May 2019.Originallyapproved in 2003.Last previous edition approved in 2012 as D694
15、112.DOI:10.1520/D6941-19.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandardsvolume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at t
16、he end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 Flow-rate,held there,ramped down to a pre-determined
