ASTM C767-93(2013)
(Test Method)Standard Test Method for Thermal Conductivity of Carbon Refractories
Standard Test Method for Thermal Conductivity of Carbon Refractories
SIGNIFICANCE AND USE
3.1 The thermal conductivity of carbon refractories is a property required for selecting their thermal transmission characteristics. Users select carbon refractories to provide specified conditions of heat loss and cold face temperature, without exceeding the temperature limitation of the carbon refractory. This test method establishes placement of thermocouples and positioning of test specimens in the calorimeter.
3.2 This procedure must be used with Test Method C201 and requires a large thermal gradient and steady state conditions. The results are based upon a mean temperature.
3.3 The data from this test method is suitable for specification acceptance, estimating heat loss and surface temperature, and the design of multi-layer refractory construction.
3.4 The use of these data requires consideration of the actual application environment and conditions.
SCOPE
1.1 This test method supplements Test Method C201, and shall be used in conjunction with that procedure to determine the thermal conductivity of carbon or carbon-bearing refractories. This test method is designed for refractories having a conductivity factor of not more than 200 Btu·in./h·ft 2·°F (28.8 W/m·K).
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: C767 − 93 (Reapproved 2013)
Standard Test Method for
Thermal Conductivity of Carbon Refractories
This standard is issued under the fixed designation C767; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2 This procedure must be used with Test Method C201
and requires a large thermal gradient and steady state condi-
1.1 This test method supplements Test Method C201, and
tions. The results are based upon a mean temperature.
shall be used in conjunction with that procedure to determine
3.3 The data from this test method is suitable for specifica-
the thermal conductivity of carbon or carbon-bearing refracto-
ries. This test method is designed for refractories having a tion acceptance, estimating heat loss and surface temperature,
and the design of multi-layer refractory construction.
conductivity factor of not more than 200 Btu·in./h·ft ·°F (28.8
W/m·K).
3.4 Theuseofthesedatarequiresconsiderationoftheactual
application environment and conditions.
1.2 The values stated in inch-pound units are to be regarded
as standard. The values given in parentheses are mathematical
4. Apparatus
conversions to SI units that are provided for information only
and are not considered standard.
4.1 The apparatus shall be in accordance with Test Method
C201 with the addition of thermocouples, back-up insulation,
1.3 This standard does not purport to address all of the
and refractory fiber paper as described in Section 5 of this test
safety concerns, if any, associated with its use. It is the
method.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
5. Test Specimen and Preparation
bility of regulatory limitations prior to use.
5.1 Select the test specimen and prepare in accordance with
Test Method C201.
2. Referenced Documents
5.2 Thermocouples—Embed calibrated thermocouples in
2.1 ASTM Standards:
the test specimen at two points for measuring temperature.
C155 Classification of Insulating Firebrick
Thermocouples sheathed with material having low reactivity
C201 Test Method for Thermal Conductivity of Refractories
with carbon must be used. Use the top thermocouple for one
E220 Test Method for Calibration of Thermocouples By
test only.
Comparison Techniques
5.3 Installation of Thermocouples—Place the hot junction
3. Significance and Use
of the thermocouples in the center of each 9 by 4 ⁄2-in. (228 by
114-mm) face and just below the surface of the test specimen.
3.1 The thermal conductivity of carbon refractories is a
Cut grooves to receive the wire in each 9 by 4 ⁄2-in. face of the
property required for selecting their thermal transmission
brick to a depth necessary to embed the thermocouple just
characteristics. Users select carbon refractories to provide
beneath the surface by means of an abrasive wheel. The layout
specified conditions of heat loss and cold face temperature,
for the grooves allows all of the cold-junction ends of the wires
without exceeding the temperature limitation of the carbon
to extend from one end of the brick. Cut a groove in the center
refractory. This test method establishes placement of thermo-
1 1
of each 9 by 4 ⁄2-in. face along the 9-in. dimension and end ⁄4
couples and positioning of test specimens in the calorimeter.
in. (6 mm) beyond the center. Before cementing the thermo-
couples in place, take measurements to obtain, within 60.01
in. (60.3 mm), the eventual distance between the center lines
This test method is under the jurisdiction of ASTM Committee C08 on
of the thermocouple junctions. Do this by measuring the
Refractories and is the direct responsibility of Subcommittee C08.02 on Thermal
2 ⁄2-in. (64-mm) dimension of the brick at the location for the
Properties.
Current edition approved Sept. 1, 2013. Published September 2013. Originally
approved in 1973. Last previous edition approved in 2009 as C767 – 93 (2009).
DOI: 10.1520/C0767-93R13. Method E220 specifies calibration procedures for thermocouples.
2 4 1
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Claud S. Gordon Co., 5710 Kenosha St., Richmond, IL60071, ⁄16–in. (2–mm)
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM sheathed Xactpak thermocouple, Cat. No. 401-2104 or equivalent.
Standards volume information, refer to the standard’s Document Summary page on Alundum Cement RA 562 supplied by the Norton Co., One New Bond St.,
the ASTM website. Worcester, MA 01606, is satisfactory for this purpose.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C767 − 93 (2013)
hot junctions and deducting the distance between the center 5.6 Placethesiliconcarbideslaboverthe9by13 ⁄2-in.(228
line of each junction in its embedded position and the surface by 342-mm) area of the three 9-in. (228-mm) brick specimen,
of the brick. andspaceit1in.nominalabovethespecimenbyplacingunder
each corner of the slab rectangular pieces of Group 28
5.4 Cover the calorimeter and inner and outer guards with a
insulating firebrick (see Classification C155) cut to measure
0.50-in. (12.7-mm) thick layer of Group 20 insulating firebrick
⁄8-in. (10-mm) square and 1-in. nominal length.
(see Classification C155) for the purpose of obtaining a higher
mean temperature in the test sample than would result by
6. Conditions of Test
placing the sample directly over the calorimeter area. Cut and
grind the back-up insulation so as to provide surfaces that are 6.1 Make a special effort to seal the furnace tightly so
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