ASTM_D_3466_-_06_2011.pdf

Designation:D346606(Reapproved 2011)Standard Test Method forIgnition Temperature of Granular Activated Carbon1This standard is issued under the fixed designation D3466;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of referenceignition temperature of granular activated carbon in flowingair.This test method provides a basis for comparing theignition characteristics of different carbons,or the change inignition characteristics of the same carbon after a period ofservice.1.2 The ignition temperature as determined by this testmethod cannot be interpreted as the probable ignition tempera-ture of the same carbon under the operating conditions of aspecific application unless those conditions are essentially thesame as those in this test method.2If it is desired to determinethe ignition temperature of the carbon under a specific set ofoperating conditions,the test may be modified to simulate suchconditions,taking into consideration the following variables:(1)air flow rate;(2)moisture content of the carbon;(3)beddepth;(4)relative humidity of the air stream;(5)heating rate;(6)contaminants(for example,hydrocarbons,etc.)in the airstream;and(7)contaminants that may have been adsorbed bythe carbon under prior service conditions.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 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 safety and health practices and determine the applica-bility of regulatory limitations prior to use.Specific precau-tionary statements are given in Section 7.2.Referenced Documents2.1 ASTM Standards:3D2652 Terminology Relating to Activated CarbonD2854 Test Method for Apparent Density of ActivatedCarbonD3195 Practice for Rotameter CalibrationE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE220 Test Method for Calibration of Thermocouples ByComparison TechniquesE300 Practice for Sampling Industrial Chemicals3.Terminology3.1 DefinitionsTerms relating to this test method aredefined in Terminology D2652.4.Summary of Test Method4.1 Asample of carbon is exposed to a heated air stream,thetemperature of which is slowly increased until the carbonignites.The temperature of the carbon bed and of the airentering the bed are recorded,and ignition is defined as thepoint at which the carbon temperature suddenly rises above thetemperature of the air entering the bed.5.Significance and Use5.1 Activated carbons used in gas-phase adsorption may besubjected to heating,either from heat applied externally to thecarbon bed,or heat generated by radioactive4contaminants,orby the adsorption process itself.If the application of heat issudden,or if no ample means to conduct the heat from thecarbon bed exists,the carbon bed may ignite.This test methodprovides a controlled laboratory test to determine the tempera-tures at which such ignition occurs.As stated in 1.2,this doesnot necessarily give the temperature at which ignition willoccur under a specific bed operating condition.This testmethod does,however,allow some ranking of carbons withregard to ignition temperature,and is a useful quality-controlmethod for unused carbons.6.Apparatus6.1 Quartz Ignition Tube and Sample Holder,as shown inFig.1.1This test method is under the jurisdiction of ASTM Committee D28 onActivated Carbon and is the direct responsibility of Subcommittee D28.04 on GasPhase Evaluation Tests.Current edition approved March 1,2011.Published May 2011.Originallyapproved in 1976.Last previous edition approved in 2006 as D4366 06.DOI:10.1520/D3466-06R11.2Y.Suzin et al.,Carbon 37(1999),pp.335346.3For referenced 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.4Milham and Kovoch,“Treatment of Airborne Radioactive Wastes,”Interna-tional Atomic Energy Agency,Vienna,1968(Paper SM-110/49).Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.2 Thermocouples,Chromel-Alumel with Inconel sheath,0.635-mm diameter,three required.6.3 Supply of Clean,Dry,Oil-Free AirThe air must bepassed through a HEPA filter and a bed of activated carboncontaining at least 300 mL of carbon per litre per minute of airflow.Relative humidity of the air must be less than 5%at25C.6.4 Flowmeter,capable of metering air flow rates to 20L/min.6.5 Heating Mantle,tape,or oven to surround the ignitiontube;at least 50 W.6.6 Variable Transformer or temperature programmer for