1、Designation: C201 93 (Reapproved 2013)Standard Test Method forThermal Conductivity of Refractories1This standard is issued under the fixed designation C201; 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the com-parative thermal conductivity of refractories under standard-ized conditions of
3、 testing. This test method is designed forrefractories having a conductivity factor of not more than 200Btuin./hft2F (2818W/mK), for a thickness of 1 in. (25 mm).1.2 Detailed ASTM test methods to be used in conjunctionwith this procedure in testing specific types of refractorymaterials are as follow
4、s: Test Method C182, Test MethodC202, Test Method C417, and Test Method C767.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 This
5、 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.2. Referenced Documents
6、2.1 ASTM Standards:2C134 Test Methods for Size, Dimensional Measurements,and Bulk Density of Refractory Brick and InsulatingFirebrickC155 Classification of Insulating FirebrickC182 Test Method for Thermal Conductivity of InsulatingFirebrickC202 Test Method for Thermal Conductivity of RefractoryBrick
7、C417 Test Method for Thermal Conductivity of UnfiredMonolithic RefractoriesC767 Test Method for Thermal Conductivity of CarbonRefractoriesE220 Test Method for Calibration of Thermocouples ByComparison Techniques3. Significance and Use3.1 The thermal conductivity of refractories is a propertyrequired
8、 for selecting their thermal transmission characteris-tics. Users select refractories to provide specified conditions ofheat loss and cold face temperature, without exceeding thetemperature limitation of the refractory. This test methodestablishes the testing for thermal conductivity of refractories
9、using the calorimeter.3.2 This procedure requires a large thermal gradient andsteady state conditions. The results are based upon a meantemperature.3.3 The data from this test method are suitable for specifi-cation acceptance, and design of multi-layer refractory con-struction.3.4 The use of these d
10、ata requires consideration of the actualapplication environment and conditions.4. Apparatus4.1 The apparatus shall conform in close detail with thatshown in the approved drawings.3The equipment is shown inFig. 1 and Fig. 2, and the essential parts are as follows:4.1.1 Heating ChamberA heating chambe
11、r, shown in Fig.3, shall be capable of being heated electrically over a tempera-ture range from 400 to 2800F (205 to 1540C) in a neutral oroxidizing atmosphere. The temperature of the heating unit shallbe controlled by a mechanism capable of maintaining thetemperature in the chamber constant to with
12、in 65F (63C).Asilicon carbide slab 1312 by 9 by 1 in. (342 by 228 by 25 mm),with the 1312 by 9-in. (342 by 228 mm) faces plane andparallel, shall be placed above the sample for the purpose ofproviding uniform heat distribution. A layer of insulationequivalent at least to 1 in. (25 mm) of Group 20 in
13、sulatingfirebrick (see Classification C155) shall be placed below thecalorimeter and guard plates.1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.02 on ThermalProperties.Current edition approved Sept. 1, 2013. Publ
14、ished September 2013. Originallyapproved in 1945. Last previous edition approved in 2009 as C201 93 (2009).DOI: 10.1520/C0201-93R13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume inform
15、ation, refer to the standards Document Summary page onthe ASTM website.3The complete set of approved drawings necessary for the construction of theapparatus and suggested operating instructions, each of which requires too muchspace to be included with this test method, were originally drafted by the
16、 InsulatingProducts Division of Babcock and Wilcox Co. ASTM has been advised that thesedrawings are no longer available. Subcommittee C08.05 currently is taking thisissue under advisement.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United State
17、s14.1.2 Calorimeter AssemblyA copper calorimeterassembly, of the design shown in Fig. 4, shall be used formeasuring the quantity of heat flowing through the testspecimen. The water circulation is such that adjacent passagescontain incoming and outgoing streams of water. The calorim-eter shall be 3 b
18、y 3 in. (76 by 76 mm) square and shall have oneinlet and one outlet water connection. The inner guard sur-rounding the calorimeter shall be 1312 by 9 in. (342 by 228mm) and shall have two inlet and two outlet water connections.The outer guard shall extend 2 in. (51 mm) laterally from theinner guard
19、and shall extend vertically to the member compris-ing the bottom of the heating chamber (see Fig. 3). Theseparation between the calorimeter and the inner guard shall be132 in. (0.8 mm).4.1.3 Water-Circulating SystemA water-circulating sys-tem shall be provided for supplying the calorimeter assemblyw
20、ith water at constant pressure and at a temperature that is notchanging at a rate greater than 1F (0.5C)/h. The inlet waterpressure shall be at least the equivalent of 10 ft of hydrostaticpressure (29.9 kPa). The inlet water temperature shall at alltimes be within +5F (+3C) or 2F (1C) of the roomtem
21、perature. Fig. 5 shows the arrangement that shall be usedfor meeting these conditions. The regulating valves for con-trolling the rate of water flow through the calorimeter assemblyshall be capable of maintaining a constant rate of flow within61 % during the test period.4.1.4 Instruments for Measuri
22、ng Temperature of SpecimenCalibrated4thermocouples shall be embedded in the testspecimen for measuring the temperature. The electromotiveforce (emf) for the temperature readings shall be taken with apotentiometer having an instrument error of not more than60.05 mV, and the cold junctions of the ther
23、mocouples shallbe immersed in a mixture of ice and water.4.1.5 Instrument for Measuring Temperature Rise in Calo-rimeter WaterA multiple differential thermocouple shall beused for measuring5within an accuracy of not less than 1 % ofthe temperature rise of the water flowing through the calorim-eter.
24、The thermocouple shall be immersed at least 312 in. (89mm) in the inlet and outlet connections, and the junctions shallbe not more than14 in. (6 mm) distant from the bottom of thecalorimeter. A calibrated differential 10X copper-constantanthermocouple shall be used, and the millivolt readings shall
25、betaken with a potentiometer having an instrument error of notmore than 60.01 mV in the range between 0 and 2 mV.4.1.6 Instruments for Measuring Temperature DifferenceBetween Calorimeter and Inner GuardCalibrated differential10X copper-constantan thermocouples shall be located in thecalorimeter and
26、inner guard for measuring5the temperaturedifferences between the calorimeter and inner guard. Thetemperature difference during a test shall be maintained at avalue less than 60.05F (60.03C). The thermocouple junc-tions shall be placed in the four wells provided for thatpurpose, and millivolt reading
27、s shall be taken with a potenti-ometer having an instrument error of not more than 60.01 mVin the range between 0 and 2 mV.5. Test Sample and Its Preparation5.1 Test SampleThe test sample shall consist of three 9-in.(228-mm) straight brick and six 9 by 212 by 214-in. (228 by 64by 57-mm) soap brick (
28、Note 2) that are representative of thematerial being tested. These brick shall be selected for unifor-mity of structure and bulk density, and they shall be free ofbroken corners or edges. One brick shall be used as the testspecimen, and one each of the other two brick shall be used asguard brick on
29、either side of the specimen. The six soap brickshall be placed around the edges of the test specimen and guardbrick to prevent side flow of heat. The test specimen and guardbrick shall cover an area of approximately 18 by 1312 in. (456by 342 mm).NOTE 1A total of nine 9-in. (228-mm) straight brick ma
30、y besubmitted for test, six of which would be cut to obtain the soap brick.5.2 Preparation of Test SampleThe9by412-in. (228 by114-mm) faces of the three straight brick and the 9 by 214-in.(228 by 57-mm) faces of the soap brick shall be ground flat andparallel, and the thickness shall not vary more t
31、han 60.01 in.(60.3 mm). The thickness shall be not more than 3 (76 mm)nor less than 2 in. (51 mm). The sides that are to be placed in4Method E220 specifies calibration procedures for thermocouples.5The following procedures are recommended: Roeser, W. F., “ThermoelectricThermometry,” and Roeser, W. F
32、., and Wensel, H. T., “Methods of TestingThermocouples and Thermocouple Materials,” Temperature, Its Measurement andControl, Reinhold Publishing Corp., New York, NY, 1941, pp. 180 and 284,respectively.NOTE 1The upper half of the heating chamber has been raised topermit introduction of the test sampl
33、es.FIG. 1 Photograph of Thermal Conductivity ApparatusC201 93 (2013)2contact shall be ground flat and at right angles to the 9 by412-in. face of the brick and the 9 by 214-in. face of the soapbrick.NOTE 2Additional instructions are given in the methods of test forspecific materials (see Section 7) c
34、oncerning the preparation of thespecimen, placing of guard brick, and the like.6. Bulk Density of Test Specimen6.1 The test specimen shall be dried at 220 to 230F (105 to110C) for 12 h, after which time its bulk density, in poundsper cubic foot (or kilograms per cubic metre) shall be deter-mined in
35、accordance with Test Methods C134, with theexception that the thickness measurement shall be made inaccordance with those methods.7. Procedure7.1 Use the procedures for testing specific types of refrac-tory materials as described in the following test methods: TestMethod C182, Test Method C202, Test
36、 Method C417, and TestMethod C767.AConstant-head water supply. JMicroregulating valves.BInlet manifold and thermometer. LWater-level valve.CCirculating pump. MMagnetic control valve.DTo drain. NOutlet manifold.ECooling coil. OOverflow pipe.FWater filter. TThermostat (controls M).GCenter calorimeter.
37、 VValves.HInner guard calorimeter. WWater inlet.IOuter guard calorimeter.FIG. 2 Diagram Showing Essential Parts of Thermal Conductivity ApparatusC201 93 (2013)38. Record of Test Data8.1 Record the following data, and record 8.1.3 to 8.1.7 foreach 2-h test period (steady state of heat flow):8.1.1 Lin
38、ear dimensions of test specimen,8.1.2 Distance between thermocouple junctions located inthe test specimen,8.1.3 Three sets of temperature readings as measured by thethermocouples in the test specimen,8.1.4 Mean temperature between each pair of thermo-couples in the test specimen as calculated from t
39、he tempera-tures recorded in 8.1.3,NOTE 1When testing insulating firebrick, the back-up insulation is removed.FIG. 3 Diagrammatic Section Through Heating ChamberFIG. 4 Design of Calorimeter and Guard RingsC201 93 (2013)48.1.5 Average rise in temperature of the water flowingthrough the calorimeter,8.
40、1.6 Average rate of water flow through the calorimeter,and8.1.7 Rate of heat flow through the test specimen per unitarea.9. Calculation9.1 Calculate the thermal conductivity as follows:k 5 qL/A t12 t2!#where:k = thermal conductivity, Btuin./hft2F (or W/mK),q = Btu/h flowing into the calorimeter (tem
41、perature rise, F(K) of the water flowing through the calorimeter timesthe weight of flowing water, lb/h (or W),L = thickness (distance between hot junctions at which t1and t2are measured), in. (or m),t1= higher of two temperatures measured in the testspecimen, F (or K),t2= lower of two temperatures
42、measured in the testspecimen, F (or K), andA = area of center calorimeter, ft2(or m2).10. Report10.1 The report shall include the following:10.1.1 Brand name or other identifying information,10.1.2 Bulk density of the dried test specimen (see Section6),10.1.3 General description of the test specimen
43、 before andafter test with respect to possible structural changes caused byexposing the test specimen to the heating chamber tempera-tures.10.1.4 The thermal conductivity data as calculated in accor-dance with Section 8 at the mean temperatures recorded duringa 2-h holding period with a steady state
44、 of heat flow, andreported at the mean of the two temperatures used in thecalculation.10.1.5 A curve showing the actual thermal conductivityvalues obtained versus mean temperatures, and10.1.6 When requested, the data recorded for Section 8 shallbe included in the report.11. Precision and Bias11.1 In
45、terlaboratory Test Data:11.1.1 Results of round-robin tests between four laborato-ries on three varieties of refractory material ranging in k-valuefrom 2 to 165 were evaluated.11.1.2 Polynomial regressions were established bycomputer, and the residual sum of squares and degree offreedom were summate
46、d for the within-laboratory variances.Between-laboratory variances were calculated from the regres-sion curves of the four laboratories at four mean temperatures(500F, 1000F, 1500F, and 2000F).11.1.3 The components of variance for the thermalconductivity, k, (Btuin./hft2F) expressed as coefficients
47、ofvariations were:Within laboratories, Vw= 3.4 %Between laboratories, Vb= 9.0 %11.2 PrecisionFor the components of variation given in11.1, two averages of test values will be considered signifi-cantly different at the 95 % probability level if the differenceequals or exceeds the critical differences
48、 listed as follows: (t =1.96)No. of Samples in EachAverageCritical differences, % of grand average k (Btuin./hft2F)(n)within-labprecisionbetween-labprecision, %1 9.4 % 26.62 6.6 % 25.83 5.5 % 25.55 4.2 % 25.011.3 Supplemental Interlaboratory Data One refractorymaterial was tested by four laboratorie
49、s in which the thermo-couples were permanently affixed by one laboratory. Polyno-mial regression equations on these data revealed the followingcomponents of variance:Within laboratories, Vw= 3.1 %Between laboratories, Vb= 2.3 %12. Keywords12.1 calorimeter; refractories; thermal conductivityCCirculating pump. LWater-level valve.DTo drain. MMagnetic control valve.ECooling coil. OOverflow pipe.FWater filter. TThermostat (controls M).GCenter calorimeter. VValves.HInner guard calorimet
