GB/T 3000-1999 Test method for air permeability of dense shaped refractory products
Some standard content:
ICS.81.080
National Standard of the People's Republic of China
GB/T3000—1999
eqvIs08841:1991
Dense shaped refractory products-Determination of permeability to gasesIssued on November 23, 1999
Implemented on August 1, 2000
Issued by the State Administration of Quality and Technical Supervision
GB/T3000—1999
This standard is equivalent to the international standard ISO8841:1991 "Dense shaped refractory products-Determination of permeability". There are slight changes in the following chapters and clauses:
2 (the referenced international standards are replaced by national standards); -3 (Note 4 is moved to Chapter 8);
5.1 (the measuring range of the rotor flowmeter is expanded, a ring for clamping thin specimens is added, and Figure 2, about the instrument for measuring air permeability under negative pressure, is deleted);
5.1.2 (the inflation pressure of the latex sleeve is changed, and Note 5, about the holder of the cubic specimen, is deleted); -5.1.4 (the provisions for measuring the flow plate by replacing air with water are deleted); -6.1 (Note 7, about the size of the cubic specimen, is deleted); -8.1C Formula (3) is deleted, the temperature range of the air dynamic viscosity value is expanded, the correction coefficient of water vapor is deleted, and the conversion formula between mbar and mmH20 is added];
-8.2 (the air permeability calculation formula is rewritten);
-8.3 (the air permeability calculation formula for the cubic specimen is deleted); -9 (Note 10 is deleted).
This standard mainly makes the following modifications to GB/T3000-1982 "Test Method for Air Permeability of Refractory Products": Add ISO Foreword and Introduction;
Expand the definition content;
-Change the number and flow range of flowmeters in Figure 1, and change the gasket ring in Figure 3 to a ring; Change the symbol of air permeability from K to u, and the unit from um2 to m\; Cancel Appendix A (Flow Measurement by Displacing Air with Water). This standard replaces GB/T30001982 from the date of implementation. This standard is proposed by the State Metallurgical Industry Bureau. This standard is under the jurisdiction of the National Technical Committee for Standardization of Refractory Materials. This standard was drafted by Luoyang Refractory Materials Research Institute. The main drafters of this standard are Qu Xuebin and Huang Haiqin. This standard was first issued on March 29, 1982. GB/T3000-1999
ISO Foreword
ISO (International Organization for Standardization) is a world federation of national standard bodies (ISO member bodies). The work of developing international standards is usually carried out by ISO's technical committees. Each member body has the right to participate in the work of a technical committee if it is interested in a project established by the committee. International organizations (official or unofficial) in contact with ISO may also participate in the work. ISO works closely with the International Electrotechnical Commission (IEC) in all aspects of electrotechnical standardization. The draft international standard adopted by the technical committee is submitted to the member groups for voting. It can only be published as an international standard if it obtains at least 75% of the votes of the member groups participating in the voting. International Standard ISO8841 was developed by the Test Methods Subcommittee of the ISO/TC33/SC2 International Organization for Standardization Technical Committee on Refractories.
GB/T3000—1999
ISO Introduction
The air permeability of a solid is a property related to the distribution of pores in the material and is therefore sensitive to changes in structure. It has no direct relationship with apparent porosity. It varies much more than porosity both within a specimen and between several specimens. It should also be noted that, unlike density and porosity, permeability is a property that varies according to the direction of measurement and sometimes also according to the direction of gas flow.
The equipment should not be affected by air flow or other local temperature changes. 1 Scope
National Standard of the People's Republic of China
Test method for permeability of dense shaped refractory productsDense shaped refractory products-Determination of permeability to gasesGB/T3000—1999
eqvIS08841:1991
Replaces GB/T3000—1982
This standard specifies the method for determining the permeability of dense shaped refractory products. For the determination of the permeability of shaped insulating refractory products, reference may be made to this standard.
The method specified in this standard takes into account the dynamic viscosity of the gas. Therefore, the results obtained cannot be directly compared with those obtained by earlier methods that did not take viscosity into account. Air is generally used during the measurement, and other gases can be used when necessary. The viscosities of air and nitrogen are given. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T1214.2—1996 Vernier caliper Vernier caliper 3 Definitions
This standard adopts the following definitions.
Permeability
The performance of a material that allows gas to pass under a pressure difference. If the volume of gas passing through the sample in a given time is known, the permeability is calculated using formula (1): V
Where: V
The volume of gas passing through the sample, m\;
The time for the volume of gas to pass through the sample, S; The permeability of the sample, m\;
The dynamic viscosity of the gas at the test temperature, Pa·S; The cross-sectional area of the sample, m2;
The height of the sample, m;
The absolute pressure of the gas, Pa;
The absolute pressure of the gas entering the sample end, Pa; The absolute pressure of the gas escaping from the sample end, Pa. 1 Formula (1) conforms to Darcy's law and is derived from the Hagen-Poiseuille law. 2 Since p is the pressure when the gas volume is measured, p=p1 when measured under positive pressure and p=P2 when measured under negative pressure. Formula (1) can be rearranged as follows:
Approved by the State Administration of Quality and Technical Supervision on November 23, 1999·(1)
Implemented on August 1, 2000
Substitute the corresponding units into formula (2)
The unit of air permeability is m2.
4 Principle
GB/T3000—1999
m·Pa·s·m
m·Pa·Pa
(2)
Dry gas passes through the sample, and the flow rate at both ends of the sample is recorded under at least three different pressure differences. The air permeability of the material is determined by calculation based on these values and the size and shape of the sample. 5 Equipment
5.1 General
The instrument for measuring air permeability under positive pressure is shown in Figure 1. The connecting tube is made of glass rather than rubber and should be as short as possible so that the pressure loss in the equipment is small compared with the pressure loss in the sample. 3a36
1-compressed gas cylinder, 2-gas pressure reducer; 3-gas filter pressure reducer: (a) leads to the rubber sleeve; (b) leads to the flow meter; 4-gas level filter, 5-rotor flowmeter: (a) 10~100cm/min, (b) 60~600cm*/mins (c) 100~1000cm/min; (d) 40~400cm/h, (e) 250~2500cm/h; 6a~6f-stop valve; 7-sample holder; 8-U-tube pressure gauge Figure 1 Schematic diagram of air permeability tester
5.1.1 Gas source
It consists of a constant pressure gas container.
5.1.2 Sample holder
The airtightness of the sample side shall be ensured by an inflatable latex sleeve. The inflation pressure depends on the nature of the latex sleeve, and is generally about 0.10-0.12 MPa (see Figure 2).
Note: When the sample height is less than 50 mm, a ring with an outer diameter of 50 mm, an inner diameter of 46 mm, and a height of 50 mm (see Figure 3) shall be placed on the sample in the holder. 5.1.3 U-tube manometer
The U-tube manometer is used to measure the pressure difference at both ends of the sample. For this type of measurement, the usual test measures shall be taken to ensure that the pressure measurement error (including the reading error of the water column height, the meniscus error, the verticality error of the manometer, and the measurement error of the liquid density in the manometer) does not exceed 1%. The pressure shall be measured close to the end face of the sample in the sample holder (5.1.2). 2
GB/T3000—1999
Note: If the pressure is measured in the connecting pipe far away from the sample, the result may be lower. 5.1.4 Gas flow measurement instrument
Consists of a sensitive rotor flow meter calibrated at a given pipeline temperature and pressure. The flow meter should be accurate to within 2%, should be regularly calibrated with the gas used, and should only measure the middle part of the scale. Connect the filling tube
Latex flexible
To the flow disc meter
2×45°
Figure 2 Sample holder
Figure 3 Ring
To the pressure gauge
5.1.5 Vernier caliper, in accordance with GB/T1214.2, the vernier reading value is accurate to 0.02mm. 5.1.6 Electric drying oven, which can be controlled at 110℃±5℃. 5.1.7 Airtight standard sample, such as an aluminum cylinder. 6 Test specimen
6.1 Dimensions
GB/T3000—1999
The test specimen should be cylindrical, with a diameter of 50mm±0.5mm and a height of 50mm±0.5mm. The perpendicularity of the test specimen to the end face axis and the parallelism between the two end faces should be within 0.5mm. Note: For thinner products, the height of the test specimen can be less than 50mm. 6.2 Preparation
The test specimen should not carry the surface layer within 4mm of the product. The direction and number of test specimens prepared relative to the pressurization direction of the product shall be in accordance with the product technical conditions or agreed upon by the relevant parties, and shall be noted in the test report. The surface of the test specimen should be free of dust generated during cutting. If wet cutting, brush it clean under water flow; if dry cutting, brush it clean under compressed air. 6.3 Drying
The specimen shall be dried in an electric drying oven (5.1.6) at 110°C ± 5°C for 2 h and shall be cooled in a desiccator to room temperature for at least 2 h.
7 Procedure
7.1 Measure the diameter and height of the specimen with a vernier caliper (5.1.5) to the nearest 0.1 mm. 7.2 Carry out a blank test with an airtight standard specimen (5.1.7) to verify that the test apparatus is airtight. 7.3 Place the specimen in the holder (5.1.2) and ensure that the pressure of the latex sleeve is sufficient to prevent air from leaking from the sides of the specimen. This can be checked by increasing the pressure on the latex sleeve. When the pressure is increased, there should be no change in the gas flow rate and the pressure difference across the specimen. 7.4 Measure the gas flow through the specimen at at least three different pressure differences across the specimen. Calculate the air permeability of the specimen for each measurement. Note: These measurements should prove that the flow rate is proportional to the pressure difference, because the equation used for calculation (see Chapter 8) is only valid for laminar flow. 7.5 If the calculated air permeability of the samples under different pressure differences deviates by more than 5%, repeat the blank test according to 7.2 to 7.4. Check the equipment and repeat the test. If it is still more than 5%, it should be noted in the test report. 8 Calculation of results
The air permeability (μ) is calculated according to formula (3), with m2 as the unit and expressed with two significant figures: xx
μ=2.16×10-6nx
Wherein: n——dynamic viscosity of gas passing through the sample at the test temperature, Pa·s; h——sample height, mm;
d——sample diameter, mm;
——gas flow rate through the sample, cm\/min; Ap——gas pressure difference at both ends of the sample (=p-p2), mmH20; p1——absolute pressure of gas entering the sample end (=p2+Ap), mmH,0; 2p1
p2——absolute pressure of gas escaping from the sample end (=the atmospheric pressure at that time and place), mmH,0. Usually, the factor 2P1
——is very close to 1 and can be ignored when measuring under small pressure difference (e.g. Ap<100mmH,0). P,+P2
10～35CThe dynamic viscosities of air and nitrogen are listed in Table 1 and Table 2 respectively. Note
11mmH,0=9.807Pa:1mbar=10.2mmH,0210-12m2=10-8cm21μm.
(3)
Test report
Dynamic viscosity
X10-6Pa·s
Dynamic viscosity
x10-pa·sWww.bzxZ.net
The test report should include the following contents:
a) Name of the testing unit;
b) Test date;
c) Implementation standard;
GB/T3000—1999
Table 1 Dynamic viscosity of air
Dynamic viscosity
X10~6Pa·s
Table 2 Gold||t t||Dynamic viscosity of nitrogen
d) Mark of the test product (manufacturer, model, batch, etc.); e) Number of specimens for each gas flow direction in the brick or product; f) Gas used;
Dynamic viscosity
X10-tPa·s
g) The pressure differences at both ends of the specimen and the corresponding gas flow rate through the specimen, temperature
h) The average value of the material permeability in each gas flow direction (relative to the pressurized direction of the brick or product); i) Explanation of the permeability deviation measured under at least three different pressure differences being greater than the allowable value (see 7.5). Dynamic viscosity
X10-'Pa·s
Dynamic viscosity
X10-6Pa·s
People's Republic of China
National Standard
Test method for air permeability of dense shaped refractory products GB/T3000—1999
Published by China Standards Press
No. 16, Sanlihebei Street, Fuxingmenwai, Beijing
Postal Code: 100045
Tel: 68522112
China Standards Press Printed by Qinhuangdao Printing House, Xinhua Bookstore, Beijing Distribution Office, Xinhua Bookstores in all regions. Copyright reserved. No reproduction allowed.
Format: 880×1230
First edition in June 2000
Printing sheet: 3/4
Number of words: 10,000
First printing in June 2000
Print run: 1-1000
Book number: 155066·1-16693
Heading: 408-15
661-0000 /16×10-6nx
Where: n——dynamic viscosity of gas passing through the sample at the test temperature, Pa·s; h—sample height, mm;
d—sample diameter, mm;
——gas flow rate through the sample, cm\/min; Ap——gas pressure difference at both ends of the sample (=p-p2), mmH20; p1——absolute pressure of gas entering the sample end (=p2+Ap), mmH,O; 2p1
p2——absolute pressure of gas escaping from the sample end (=the atmospheric pressure at that time and place), mmH,O. Usually, the factor 2P1
——is very close to 1 and can be ignored when measured under a small pressure difference (e.g. Ap<100mmH,0). P,+P2
The dynamic viscosities of air and nitrogen at 10～35C are listed in Table 1 and Table 2 respectively. Note
11mmH,0=9.807Pa:1mbar=10.2mmH,0210-12m2=10-8cm21μm.
(3)
Test report
Dynamic viscosity
X10-6Pa·s
Dynamic viscosity
x10-pa·s
The test report should include the following contents:
a) Name of the testing unit;
b) Test date;
c) Implementation standard;
GB/T3000—1999
Table 1 Dynamic viscosity of air
Dynamic viscosity
X10~6Pa·s
Table 2 Gold||t t||Dynamic viscosity of nitrogen
d) Mark of the test product (manufacturer, model, batch, etc.); e) Number of specimens for each gas flow direction in the brick or product; f) Gas used;
Dynamic viscosity
X10-tPa·s
g) The pressure differences at both ends of the specimen and the corresponding gas flow rate through the specimen, temperature
h) The average value of the material permeability in each gas flow direction (relative to the pressurized direction of the brick or product); i) Explanation of the permeability deviation measured under at least three different pressure differences being greater than the allowable value (see 7.5). Dynamic viscosity
X10-'Pa·s
Dynamic viscosity
X10-6Pa·s
People's Republic of China
National Standard
Test method for air permeability of dense shaped refractory products GB/T3000—1999
Published by China Standards Press
No. 16, Sanlihebei Street, Fuxingmenwai, Beijing
Postal Code: 100045
Tel: 68522112
China Standards Press Printed by Qinhuangdao Printing House, Xinhua Bookstore, Beijing Distribution Office, Xinhua Bookstores in all regions. Copyright reserved. No reproduction allowed.
Format: 880×1230
First edition in June 2000
Printing sheet: 3/4
Number of words: 10,000
First printing in June 2000
Print run: 1-1000
Book number: 155066·1-16693
Heading: 408-15
661-0000 /16×10-6nx
Where: n——dynamic viscosity of gas passing through the sample at the test temperature, Pa·s; h—sample height, mm;
d—sample diameter, mm;
——gas flow rate through the sample, cm\/min; Ap——gas pressure difference at both ends of the sample (=p-p2), mmH20; p1——absolute pressure of gas entering the sample end (=p2+Ap), mmH,O; 2p1
p2——absolute pressure of gas escaping from the sample end (=the atmospheric pressure at that time and place), mmH,O. Usually, the factor 2P1
——is very close to 1 and can be ignored when measured under a small pressure difference (e.g. Ap<100mmH,0). P,+P2
The dynamic viscosities of air and nitrogen at 10～35C are listed in Table 1 and Table 2 respectively. Note
11mmH,0=9.807Pa:1mbar=10.2mmH,0210-12m2=10-8cm21μm.
(3)
Test report
Dynamic viscosity
X10-6Pa·s
Dynamic viscosity
x10-pa·s
The test report should include the following contents:
a) Name of the testing unit;
b) Test date;
c) Implementation standard;
GB/T3000—1999
Table 1 Dynamic viscosity of air
Dynamic viscosity
X10~6Pa·s
Table 2 Gold||t t||Dynamic viscosity of nitrogen
d) Mark of the test product (manufacturer, model, batch, etc.); e) Number of specimens for each gas flow direction in the brick or product; f) Gas used;
Dynamic viscosity
X10-tPa·s
g) The pressure differences at both ends of the specimen and the corresponding gas flow rate through the specimen, temperature
h) The average value of the material permeability in each gas flow direction (relative to the pressurized direction of the brick or product); i) Explanation of the permeability deviation measured under at least three different pressure differences being greater than the allowable value (see 7.5). Dynamic viscosity
X10-'Pa·s
Dynamic viscosity
X10-6Pa·s
People's Republic of China
National Standard
Test method for air permeability of dense shaped refractory products GB/T3000—1999
Published by China Standards Press
No. 16, Sanlihebei Street, Fuxingmenwai, Beijing
Postal Code: 100045
Tel: 68522112
China Standards Press Printed by Qinhuangdao Printing House, Xinhua Bookstore, Beijing Distribution Office, Xinhua Bookstores in all regions. Copyright reserved. No reproduction allowed.
Format: 880×1230
First edition in June 2000
Printing sheet: 3/4
Number of words: 10,000
First printing in June 2000
Print run: 1-1000
Book number: 155066·1-16693
Heading: 408-15
661-0000 /
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