1、Designation: D 3466 06Standard Test Method forIgnition Temperature of Granular Activated Carbon1This standard is issued under the fixed designation D 3466; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 met
3、hod 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 s
4、ame 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 suchc
5、onditions, 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 ads
6、orbed bythe carbon under prior service conditions.1.3 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 r
7、egulatory limitations prior to use. Specific precau-tionary statements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:3D 2652 Terminology Relating to Activated CarbonD 2854 Test Method for Apparent Density of ActivatedCarbonD 3195 Practice for Rotameter CalibrationE11 Specification
8、 for Wire Cloth and Sieves for TestingPurposesE 220 Test Method for Calibration of Thermocouples ByComparison TechniquesE 300 Practice for Sampling Industrial Chemicals3. Terminology3.1 DefinitionsTerms relating to this test method aredefined in Terminology D 2652.4. Summary of Test Method4.1 Asampl
9、e 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 o
10、f 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 issudde
11、n, 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 will
12、occur 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. 1.6.2 Thermocouples, Chrom
13、el-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 % at25
14、C.1This test method is under the jurisdiction of ASTM Committee D28 onActivated Carbon, and is the direct responsibility of Subcommittee D 28.04 on GasPhase Evaluation Tests.Current edition approved April 1, 2006. Published April 2006. Originallyapproved in 1976. Last previous edition approved in 19
15、98 as D3466 76 (1998).2Y. Suzin et al., Carbon 37 (1999), pp. 3353463For 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 w
16、ebsite.4Milham and Kovoch, “Treatment of Airborne Radioactive Wastes,” Interna-tional Atomic Energy Agency, Vienna, 1968. (Paper SM-110/49).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.4 Flowmeter, capable of metering air flow r
17、ates 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 forheater.6.7 Supply of Compressed Nitrogen.6.8 Quartz Beads, 4-mm in diameter or smaller as needed toprevent fluidization.6.9 Sieves, (two) 76.2-mm in dia
18、meter, 150-m conformingto Specification E11.6.10 Potentiometric Recorder or equivalent readout forthermocouples (3 or more points).6.11 Programmable Temperature Controller (Optional).7. Hazards7.1 The temperature rise in a carbon bed is quite sudden atignition. An adequate supply of nitrogen and an
19、operator mustbe present to quench the fire when this rise occurs. Do not stopnitrogen flow until all thermocouples indicate temperaturessubstantially below ignition.7.2 Combustion products of carbon or carbon impreg-nantsmay be toxic. It is advisable to conduct this test in a fume hood.8. Sampling8.
20、1 Guidance in sampling granular activated carbon is givenin Practice E 300.9. Preparation of Apparatus9.1 Assemble apparatus as shown in Fig. 1 and Fig. 2.9.2 Leak test the assembly and eliminate any leakage.9.3 Obtain a representative sample of carbon of approxi-mately 35 mL in accordance with Prac
21、tice E 300. Blow cleandry oil-free air through the sample, retained between 150-msieves, to remove carbon dust. The flow velocity through thesieves shall be 60 6 20 m/min.FIG. 1 Ignition Tube and Sample AssemblyD 3466 0629.4 Fill the ignition tube (Fig. 1) to a depth of 25 6 1 mm,using the apparatus
22、 and procedure described in Test MethodD 2854. Cover the sample with quartz beads to a depth of atleast 15 mm to prevent fluidization of the carbon bed.10. Calibration10.1 Thermocouples, recorder, and flowmeters require peri-odic calibration by standard laboratory techniques, for ex-ample, Method E
23、220, for thermocouples, and Practice D 3195,for rotometertype flowmeters.11. Procedure11.1 Adjust the air flow rate to 14.7 6 0.3 L/min, equivalentto a superificial velocity of 30 6 0.5 m/min.11.2 Adjust the variable transformer or temperature pro-grammer to increase the temperature of the air strea
24、m reachingthe sample at a rate of approximately 10C/min (as indicatedby Thermocouple T-13). Continue until air temperature reachesapproximately 150C, or when the air temperature is approxi-mately 50C below the anticipated ignition temperature of thesample. At this point, adjust the variable transfor
25、mer orprogram drive to reduce the air heating rate to approximately 2to 3C/min.11.3 Maintain the heating rate of 2 to 3C/min until ignitionis achieved, as indicated by a sudden rise in the temperaturemeasured by thermocouple T-1 or T-2.11.4 On ignition, cut off air flow immediately and introducenitr
26、ogen to quench fire.12. Interpretation of Results12.1 Obtain time-temperature plots, Fig. 3, of the tempera-tures measured by thermocouples T-1 and T-2. Draw tangentsto the heating curves before and after ignition, as shown in Fig.3; ignition temperature is the intersection of the tangents.Repeat fo
27、r thermocouple T-1. The ignition temperature for thecarbon is defined from the thermocouple that first showsignition.13. Report13.1 Report the following information:13.1.1 Name of the carbon manufacturer,13.1.2 Grade designation and nominal particle size range,13.1.3 Average ignition temperature and
28、 whether ignitionoccurred first at the upstream (T-1) or downstream (T-2)thermocouple,13.1.4 Temperature of the inlet air at the time of ignition,13.1.5 Name of the agency and technician making the test,and13.1.6 Identification number and date of the test.14. Precision and Bias14.1 The bias of this
29、test method is basically the bias of thethermocouple-recorder system. The sensitivity of the ignitionpoint to gas velocity varies from carbon to carbon. Milham andKovach have reported a maximum rate of change of ignitionpoint of 250C/(m/s). Thus, the control of flow to 60.5 m/min,(0.0083 m/s) requir
30、ed in 11.1, should introduce no more than62C error in the measurement. Such repeatability appears tohave been obtained in the above-mentioned studies, when oneconsiders reasonable variations in properties for successivesamples of the same carbons; the actual ignition temperaturespread at a given vel
31、ocity did not exceed 65C in the vicinityof 500C.15. Keywords15.1 activated carbonFIG. 2 Ignition Apparatus SchematicD 3466 063ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are e
32、xpressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not rev
33、ised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you m
34、ay attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United St
35、ates. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).FIG. 3 Determination of Temperature of Carbon at IgnitionD 3466 064
