SANS 1399-2008 Wood charcoal and charcoal briquettes for household use《家用木炭和木炭块》.pdf

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1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-21489-0 SANS 1399:2008Edition 2.3Any reference to SABS 1399 is deemedto be a reference to this standard(Government Notice No. 1373 of 8 No

4、vember 2002)SOUTH AFRICAN NATIONAL STANDARD Wood charcoal and charcoal briquettes for household use Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa S

5、ANS 1399:2008 Edition 2.3 Table of changes Change No. Date Scope Amdt 1 2000 Amended to omit the compression strength requirement and test for charcoal briquettes. Amdt 2 2002 Amended to delete the references to SABS 197 and replace it with SANS 3310-2/ ISO 3310-2. Amdt 3 2008 Amended to change the

6、designation of SABS standards to SANS standards, to update the definition of “acceptable“, to change the chemical requirements for volatile matter content, ash content and fixed carbon content, and to delete reference to the certification mark. Foreword This South African standard was approved by Na

7、tional Committee StanSA SC 5110.08E, Sawn timber and semi-manufactured timber products Wood charcoal and m2is the mass of the total contents of the container before sieving, in grams. Record the mean of the two results. 5.2.4.2 For each container calculate, to the nearest 0,1 %, the quantity that pa

8、ssed through the 9,5 mm test sieve, as follows: 23mm 100 SANS 1399:2008 Edition 2.3 7 where m2is the mass of the total contents of the container before sieving, in grams; and m3is the mass of the quantity that passed through the 9,5 mm test sieve, in grams. Record the mean of the two results. 5.2.4.

9、3 Check for compliance with 4.4.2. 5.3 Sieve analysis for charcoal briquettes 5.3.1 Apparatus 5.3.1.1 Balances, as in 5.2.1.1. 5.3.1.2 Round test sieve, that complies with the requirements of SANS 3310-2, that is equipped with a cover and a receiver, and that has square apertures of nominal size 9,5

10、 mm. Amdt 2 5.3.2 Test specimens Take, at random, two containers from the sample under test (see B.2.2.2 of annex B). 5.3.3 Procedure Determine the mass of the contents of one container to the nearest 20 g. Separate all the unbroken briquettes from the broken briquettes and fines. Using a horizontal

11、 to and fro movement, sieve the broken briquettes and fines on the test sieve in such increments as to ensure that, on the completion of the sieving of each increment, each piece in the increment has been in direct contact with the sieve plate. Determine the mass of the quantity that passed through

12、the test sieve to the nearest 1 g. Repeat the test on the second container. Retain all the unbroken briquettes from each container (see 5.6.3 and 5.7). 5.3.4 Expression of results 5.3.4.1 For each container calculate, to the nearest 0,1 %, the quantity that passed through the test sieve, as follows:

13、 54mm 100 where m4is the mass of the quantity that passed through the 9,5 mm test sieve, in grams; and m5is the mass of the total contents of the container, in grams. Record the mean of the two results. 5.3.4.2 Check for compliance with 4.4.2. SANS 1399:2008 Edition 2.3 8 5.4 Drop resistance of cont

14、ainer content 5.4.1 Apparatus 5.4.1.1 Dropping device, comprising a divided table (or single-leaf device), fitted with a release mechanism, that is so spring-operated as to produce, from a height of 750 mm, free fall of the container without rotational or sideways motion of the container. 5.4.1.2 Im

15、pact surface, comprising a rigid and level concrete surface (or a steel plate embedded in concrete) of sufficient strength and rigidity to withstand repeated impacts of test material without significant deflection or movement. 5.4.2 Test specimens Take, at random, two of the remaining containers fro

16、m the sample under test (see B.2.2.2 of annex B). 5.4.3 Procedure So position one of the containers upright that, when released, it will fall on its base. Operate the release mechanism and drop the container. Unless the container has failed, invert it, gently distribute the contents as symmetrically

17、 as possible and repeat the drop. Repeat this procedure with the container positioned on its right-hand side and on its left-hand side. Repeat the test on the second container. If a container fails, take a new container from the remainder of the sample under test (see B.2.2.2 of annex B), and repeat

18、 the procedure. For each container determine, as in 5.2 or 5.3 (as relevant), the percentage (by mass) of the contents that passed through a 9,5 mm test sieve. 5.5 Deleted by amendment No. 1. 5.6 Moisture content 5.6.1 Principle A test specimen is heated to a constant mass in an air-oven at a temper

19、ature of 105 C and the percentage moisture content is calculated from the loss in mass of the test specimen. 5.6.2 Apparatus 5.6.2.1 Air oven, capable of maintaining a substantially uniform temperature of 105 C, and such that the rate of atmosphere change is sufficiently rapid for the test. 5.6.2.2

20、Balance, accurate to 1,0 g. 5.6.2.3 Tray, of area approximately 0,1 m2and of depth 25 mm, made of non-corrodible material such as stainless steel, tinned steel or aluminium. The tray shall be clean, dry and accurately tared. 5.6.3 Test specimen Approximately 500 g of lump charcoal or charcoal brique

21、ttes. For the test on briquettes, take at random a similar number of unbroken briquettes from each container retained in terms of 5.3.3 until approximately 500 g is obtained and, for the test on lump charcoal, take a test mass of 250 g from the contents of each container retained in terms of 5.2.3.

22、SANS 1399:2008 Edition 2.3 9 5.6.4 Procedure Determine the mass m1of the dry empty tray. Transfer the specimen as completely as possible to the tray and spread the specimen evenly. Determine the initial mass m2of the tray and contents. Place the charged tray in the oven, preheated to 105 C, until co

23、nstant mass is obtained. Determine the mass m3of the heated tray and contents while they are still hot, to avoid absorption of moisture during cooling. 5.6.5 Expression of results 5.6.5.1 The moisture content M of the charcoal, expressed as a percentage (by mass), is given by the equation M = )()(12

24、32mmmm 100 where m1is the mass of the empty tray, in grams; m2is the initial mass of the tray plus the test specimen, in grams; m3is the mass of the tray plus the test specimen after heating, in grams. Report the result (preferably the mean of duplicate determinations) to the nearest 0,1 % (by mass)

25、. 5.6.5.2 Check for compliance with 4.5.1. 5.6.6 Precision of results The results of duplicate determinations shall not differ by more than the appropriate of the values given in table 1. Table 1 Precision of results 1 2 Moisture content (by mass) % Same laboratory, repeatability 5 0,5 % absolute 0,

26、5 % absolute NOTE Limits for reproducibility (different laboratories) have not yet been established because results obtained in different laboratories depend on the humidity conditions, which can vary from laboratory to laboratory. 5.7 Preparation of test material for volatile matter content and ash

27、 content Take, at random, eight of the unbroken briquettes (four from each container) retained in terms of 5.3.3 or, in the case of lump charcoal, a specimen of mass at least 200 g from the contents of each container retained in terms of 5.2.3. Quickly (to avoid heat build-up) pulverize or grind the

28、 specimen such that it passes through a 250 m sieve, mix well, and store in an airtight container. SANS 1399:2008 Edition 2.3 10 5.8 Volatile matter content 5.8.1 Principle A test specimen from which the moisture content has been extracted, is heated for 7 min at 900 C out of contact with air. The p

29、ercentage of the volatile matter is calculated from the loss in mass of the test specimen. 5.8.2 Apparatus 5.8.2.1 Muffle furnace, heated by electricity, in which a zone of adequate size is maintained at a constant and uniform temperature of 900 C 10 C. The furnace may be of the stop-ended type, or

30、fitted at the back with a flue of diameter approximately 25 mm and of length approximately 150 mm. The heat capacity of the furnace is such that, with an initial temperature of 900 C, a minimum temperature of 885 C is regained within 4 min (and preferably within 3 min) of the insertion of a cold sta

31、nd and its crucible(s), the temperature being measured with the unsheathed thermocouple (see 5.8.2.2) by inserting its thermojunction midway between the floor of the furnace and the base of the crucible in its stand. If the stand holds more than one crucible, the temperature under each crucible is c

32、hecked in the same manner. Normally, the furnace will have been designed specifically for receiving either one crucible and its stand or a number of crucibles in one stand. NOTE 1 The position of the crucible stand is chosen within the zone of uniform temperature and this position is used for all de

33、terminations. NOTE 2 The temperature of 900 C is attained as closely as possible and the tolerance of 10 C is specified to compensate for inherent errors in the temperature measurement and lack of uniformity in the temperature distribution. 5.8.2.2 Pyrometer, with an unsheathed thermocouple, of wire

34、 of diameter not exceeding 1 mm, for checking the temperature characteristics of the muffle furnace. NOTE 1 A sheathed thermocouple can be permanently installed in the furnace with its thermojunction as close as possible to the centre of the zone of uniform temperature. In this case, its temperature

35、 readings are correlated at frequent intervals with those of the unsheathed thermocouple. (Because of the thickness of the sheathed thermocouple, it cannot be inserted under a crucible.) NOTE 2 The temperature/electromotive force relationship of a thermojunction maintained at elevated temperatures g

36、radually changes with time. 5.8.2.3 Cylindrical crucible, with a well-fitting lid, both made of fused silica. The crucible and lid have a combined mass of between 10 g and 14 g, and their dimensions approximate those shown in figure 1. The fit of the lid to the crucible is critical for the determina

37、tion and a lid is so selected to match the crucible that the gap between the lid and the crucible does not exceed 0,5 mm. After selection, the crucible and the lid are ground together to give smooth-fitting surfaces and are thereafter used solely as a matched pair. NOTE Crucibles of other refractory

38、 materials or of platinum may be used, provided that they give, within the prescribed limits of precision (see 5.8.6), the same results as the silica crucibles. 5.8.2.4 Suitable stand, in which to place the crucible(s) in the muffle furnace, and such that the appropriate rate of heating can be achie

39、ved. SANS 1399:2008 Edition 2.3 11 5.8.2.5 Desiccant, of fresh or freshly regenerated self-indicating gel. 5.8.2.6 Desiccator, of suitable dimensions, that contains the desiccant. 5.8.2.7 Analytical balance, accurate to within 0,1 mg. 5.8.2.8 Stopwatch. Figure 1 Silica crucible and lid 5.8.3 Test sp

40、ecimen A test specimen taken from the material prepared in accordance with 5.7. Ensure that the preprepared material is thoroughly mixed (preferably by mechanical means) for at least 1 min. 5.8.4 Procedure Heat the crucible and lid (or the set of crucibles and lids (as relevant) in the muffle furnac

41、e at 900 C 10 C for 7 min. Remove the crucible(s) from the furnace, allow to cool on a thick metal plate for 10 min and then for 15 min in the desiccator located next to the balance. When cooled to room temperature, determine (in turn) the mass m1of each clean empty crucible and lid, to the nearest

42、0,1 mg, and return the lid to the desiccator. Weigh, to the nearest 0,1 mg, into each crucible, 1,00 g to 1,01 g of the test specimen, and heat the crucible and test specimen, without the lid, in an air oven (see 5.6.2.1) at 105 C for 1 h. (This initial action is critical, since the result has to be

43、 expressed on a dry basis.) Cool the crucible and test specimen in the desiccator for 15 min. Replace the lid and determine, to the nearest 0,1 mg, the initial mass m2of each crucible plus lid plus dried specimen. SANS 1399:2008 Edition 2.3 12 Tap each crucible on a clean, hard surface until the spe

44、cimen forms a layer of uniform thickness at the bottom of the crucible. Place the charged crucible(s) in the stand and, in the case of multiple determination, fill the vacant places in the stand with empty crucibles. Place the stand within the zone of uniform temperature in the furnace, preheated to

45、 900 C, for exactly 7 min, remove the crucible(s), allow to cool on a thick metal plate for 10 min and then in the desiccator for 15 min. When the crucible(s) has (have) cooled to room temperature, determine the mass of each charged crucible to the nearest 0,1 mg and record the final mass m3of each.

46、 NOTE Precisely similar treatment of a crucible before and after determination minimizes the effect of any film of water absorbed on its surface, and the rapid cooling reduces absorption of moisture by the charcoal residue. 5.8.5 Expression of results 5.8.5.1 The volatile matter content V, expressed

47、 as a percentage (by mass), is given by the equation V = )()(1232mmmm 100 where m1is the mass of the empty clean crucible plus lid, in grams; m2is the mass of the crucible plus lid plus specimen after drying at 105 C for 1 h, in grams; m3is the mass of the crucible plus lid plus residue after heatin

48、g, in grams. Report the result (preferably the mean of duplicate determinations), to the nearest 0,1 % (by mass). 5.8.5.2 Check for compliance with 4.5.2. 5.8.6 Precision of result The results of duplicate determinations shall not differ by more than the appropriate of the values given in table 2. T

49、able 2 Precision of results 1 2 3 Volatile matter content (by mass) % Same laboratory, repeatability Different laboratories, reproducibility 10 3 % of the mean result The greater of 0,5 % absolute and 4 % of the mean result SANS 1399:2008 Edition 2.3 13 5.9 Ash content 5.9.1 Principle A test specimen from which the moisture content has been extracted, is heated in air at a specified rate up to a temperature of 710 C 10 C and maintained at this temperature until constant in mass. The percentage of the ash is calculated from the mass of the re