CEN TR 15149-3-2014 Solid biofuels - Determination of particle size distribution - Part 3 Rotary screen method《固体生物燃料 粒度分布的测定 第3部分 旋转筛法》.pdf

1、BSI Standards PublicationPD CEN/TR 15149-3:2014Solid biofuels Determinationof particle size distributionPart 3: Rotary screen methodPD CEN/TR 15149-3:2014 PUBLISHED DOCUMENTNational forewordThis Published Document is the UK implementation of CEN/TR15149-3:2014. It supersedes DD CEN/TS 15149-3:2006 w

2、hich iswithdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PTI/17, Solid biofuels.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract.

3、 Users are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 73877 7ICS 75.160.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This Published Document was published under the authorit

4、y of theStandards Policy and Strategy Committee on 30 November 2014.Amendments issued since publicationDate Text affectedPD CEN/TR 15149-3:2014TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 15149-3 November 2014 ICS 75.160.10 Supersedes CEN/TS 15149-3:2006English Version Solid biofuel

5、s - Determination of particle size distribution - Part 3: Rotary screen method Biocombustibles solides - Dtermination de la distribution granulomtrique - Partie 3 : Mthode au tamis rotatif Feste Biobrennstoffe - Bestimmung der Teilchengrenverteilung - Teil 3: Verfahren mit rotierendem Sieb This Tech

6、nical Report was approved by CEN on 18 July 2011. It has been drawn up by the Technical Committee CEN/TC 335. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, German

7、y, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR N

8、ORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TR 15149-3:2014 EPD CEN/TR 15149-3:2014CEN/TR 15149-3:2014 (E) 2 Contents Page Foreword 3 Introduction .4

9、 1 Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Principle 5 5 Apparatus .5 6 Sample preparation .7 6.1 Sample size 7 6.2 Sample preparation .7 7 Procedure .7 8 Calculation 8 9 Precision and bias .9 10 Test report . 10 Annex A (informative) Example of a rotary sieving machine 11 Bibl

10、iography . 12 PD CEN/TR 15149-3:2014CEN/TR 15149-3:2014 (E) 3 Foreword This document (CEN/TR 15149-3:2014) has been prepared by Technical Committee CEN/TC 335 “Solid biofuels”, the secretariat of which is held by SIS. Attention is drawn to the possibility that some of the elements of this document m

11、ay be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes CEN/TS 15149-3:2006. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Associ

12、ation. EN 15149, Solid biofuels Determination of particle size distribution, consists of the following parts: Part 1: Oscillating screen method using sieve apertures of 1 mm and above; Part 2: Vibrating screen method using sieve apertures of 3,15 mm and below; Part 3: Rotary screen method Technical

13、Report; the present document. The most significant changes since the latest edition of this text are the following ones: The former edition was a Technical Specification; it was turned into the present Technical Report. References have been consistently updated. PD CEN/TR 15149-3:2014CEN/TR 15149-3:

14、2014 (E) 4 Introduction Part 1 describes the reference method for size classification of samples with a nominal top size of 3,15 mm and over. Part 2 describes the reference methods for all samples with a nominal top size below 3,15 mm. Part 3 describes an innovative method, by which the degree of ov

15、erestimating the fine particle fractions is reduced. As it is currently not generally available, it is here proposed for research and development purposes or for individual quality management processes, in which the quality requirements are bilaterally defined between the suppliers and consumers bas

16、ed on this method. NOTE The nominal top size is defined as the aperture size of the sieve where at least 95 % by mass of the material passes (see Bibliography). PD CEN/TR 15149-3:2014CEN/TR 15149-3:2014 (E) 5 1 Scope This Technical Report specifies a method for the determination of the size distribu

17、tion of particulate biofuels by the rotary screen method. The method described is meant for particulate biofuels only, namely materials that either have been reduced in size, such as most wood fuels, or are physically in a particulate form e.g. olive stones, nutshells, grain, etc. This document appl

18、ies to particulate uncompressed fuels with a nominal top size of 3,15 mm and over, e.g. wood chips, hog fuel, olive stones, etc. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated refer

19、ences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 14778, Solid biofuels Sampling EN 14780, Solid biofuels Sample preparation EN 14774-1, Solid biofuels Determination of moisture content - Oven dry metho

20、d Part 1: Total moisture Reference method EN 14774-2, Solid biofuels Determination of moisture content Oven dry method Part 2: Total moisture Simplified method EN 15149-2, Solid biofuels Determination of particle size distribution Part 2: Vibrating screen method using sieve apertures of 3,15 mm and

21、below EN ISO 16559, Solid biofuels Terminology, definitions and descriptions (ISO 16559) ISO 3310-2, Test sieves Technical requirements and testing Part 2: Test sieves of perforated metal plate 3 Terms and definitions For the purpose of this document, the terms and definitions given in EN ISO 16559

22、apply. 3.1 nominal top size aperture size of the sieve where at least 95 % by mass of the material passes 4 Principle A sample is subjected to sieving through sieves in a rotary sieving machine sorting the particles by increasing size. 5 Apparatus 5.1 Rotary screen. For the test a rotary sieving dev

23、ice is required for which the operating principle is shown in Figure 1. The rotary sieving device consists of five joined cylindrical sieve rings each with an inner diameter of 500 mm PD CEN/TR 15149-3:2014CEN/TR 15149-3:2014 (E) 6 ( 15 mm). The height (length) of each of the 5 sieve rings is 400 mm

24、 with a maximum of 20 mm imperforated (“blind”) surface at each side; as a consequence each ring is having an effective sieving length of 360 mm or higher. All five cylinder rings (sieves) are evenly long and consecutively connected to each other, thus forming a drum. The inner surface of the drum s

25、hall be constructed in a way, which allows the particles to slide from one ring to another without interruption. Downward to the direction of flow the drum is inclined at an angle of 3 ( 0,2) towards the horizontal ground. The drum shall be rotating at a speed 16 rotations per minute. Due to both, i

26、nclination and rotation of the drum, the sample is continuously being transported forward in the drum over the rotating sieves. Thereby the particles are separated by their size by passing through the sieve holes and falling into individual collecting pans underneath each sieve cylinder. Large parti

27、cles, which have not passed through any sieve holes, are finally being discharged from the drum into a final collecting pan. The size of each individual pan should be at least 70 % of the initial test sample volume. Key 1 material addition 2 increasing hole diameter 3 material flow direction 4 colle

28、cting pans Figure 1 Operating principle of rotating sieves The geometry of the apertures and the thickness of the sieves shall be in accordance with the requirements of ISO 3310-2. The aperture sizes of the sieves shall be chosen according to the size specification of the sample material. It is reco

29、mmended that the diameters of the holes in the sieves are 3,15 mm, 8 mm, 16 mm, 45 mm and 63 mm. On the rotating drum the cylinders shall be arranged by increasing sieve hole diameters, starting with the smallest sieve holes where the sample material shall be fed on (see Figure 1). 5.2 Balance. A ba

30、lance capable of measuring the mass of the sample to be sieved to the nearest 0,1 g is required. PD CEN/TR 15149-3:2014CEN/TR 15149-3:2014 (E) 7 6 Sample preparation 6.1 Sample size The minimum size of the test sample for the determination of the size distribution shall be 8 l and shall have been sa

31、mpled according to EN 14778. For fine grade biofuels, where 100 % of the particles pass sieve holes of 45 mm diameter, a smaller sample size of minimum 4 l can be used. The sample should include material for determination of size distribution and moisture content. 6.2 Sample preparation The sample s

32、hall be sieved at a moisture content below 20 % wet base, thus preventing the particles from sticking together or loosing moisture during the sieving process. If necessary the sample shall be pre-dried. Drying is done according to EN 14780. NOTE By pre-drying, as described in EN 14780, the sample is

33、 brought into equilibrium with the humidity of the surrounding atmosphere. Determine the moisture content of the material to be sieved on a separate sub-sample following the procedure given in EN 14774-1 or EN 14774-2. The moisture content shall be determined and reported concurrently with the parti

34、cle size distribution determination. 7 Procedure Assemble and operate the rotary sieve with the appropriate sieves in accordance with 5.1. Weigh the sample to the nearest 0,1 g of the total sample mass. Feed the sample material continuously into the rotating sieve at a constant feeding rate of 1 l p

35、er min. This can, for example, be achieved by letting the sample material fall over an infeed slide onto the edge of the first cylinder. The homogeneous feeding rate can be achieved either by a mechanical feeding mechanism or by hand feeding onto the slide. If feeding is done by hand, the sample sho

36、uld be divided into several portions (for example 8 portions) of equal volume; these portions are then dropped onto the slide sequentially in a way that ensures an even and uninterrupted flow throughout the total feeding time (e.g. 8 1 min). If a larger sample size (more than 8 l) is processed, the

37、capacity of the collecting pans may be exceeded or the sample may have to be separated in two or more portions and be processed subsequently. Stop the rotation when no more material is remaining in the rotating drum. In case that a particle sticks in a sieving hole, the sieve shall be stopped and th

38、e particle shall be re-fed in the sieve. Restart the rotary sieve and let the sieve empty. All particles larger than 100 mm (maximum dimension) shall be hand sorted into one or more fractions regardless from which sieve or collecting pan they are collected. Weigh the net material in each fraction wi

39、th an accuracy of 0,1 g and record the mass in a scheme equal to Table 1. NOTE In many cases it is useful to identify the largest particle (maximum dimension) and record it in a scheme equal to Table 1. The information on the longest particle may be required for computing the median particle size or

40、 for illustrating the results in a cumulative size distribution curve. PD CEN/TR 15149-3:2014CEN/TR 15149-3:2014 (E) 8 In size classification by sieving, some of the thin particles, which are longer than the hole diameter, will pass the sieve and mix with the particles in the smaller size fractions.

41、 Most of these particles shall remain in that fraction. Only particles which are over 100 mm (maximum dimension) shall be sorted by hand, regardless from which collecting pan they are collected. If fractionation of the finest material, which fell through the sieve holes of the first cylinder ring, i

42、s required, proceed as described in EN 15149-2. 8 Calculation The result is expressed as a percentage of the total mass of all fractions. If more than one sample (sub-sample) is processed the weight of the respective fractions shall be added up before calculating the overall percentage of each class

43、. This procedure is demonstrated in Table 1. PD CEN/TR 15149-3:2014CEN/TR 15149-3:2014 (E) 9 Table 1 Results of the size distribution analysis (1) (2) (3) (4) (5) Fraction name Fraction, in mm Mass of fraction in subsample 1, in grams Mass of fraction in subsample 2, in grams Mass of fraction in sub

44、sample 3, in grams (add more columns if necessary) Total mass of fractions in Columns 1, 2 and 3 (or more), in grams Percentage of fraction (by mass), in % (based on total mass in Column 4) 1st Collecting pan below 3,15 2nd Collecting pan 3,158 3rd Collecting pan 816 4th Collecting pan 1645 5th Coll

45、ecting pan 4563 6th Collecting pan 63100 Hand sorting To be specified Hand sorting To be specified Total mass of all fractions all 100 % Other recordings: Total mass of test portion Number of Overlong (Specify fraction in mm) Number of Overlong (Specify fraction in mm) Length of longest particle ove

46、rall, in mm Difference between the total mass of the test portion and the total mass of all fractions (column 4) in percent of the total test portion Moisture content of the sieved sample, in % w/w. The difference between the total mass of test portion and the total mass of all fractions as indicate

47、d in Table 1 shall be smaller than 2 %. Larger differences may occur due to lost or retained particles or due to changes in moisture content. In this case the causes for the deviation should be investigated and the measurement repeated. In case this is impossible or the result still deviates more th

48、an accepted this shall be reported. 9 Precision and bias Because of the varying nature of solid biofuels covered by this document it is not possible at this time to give a precision statement (repeatability or reproducibility) for this test method. PD CEN/TR 15149-3:2014CEN/TR 15149-3:2014 (E) 10 10

49、 Test report The test report shall include at least the following information: identification of the laboratory and the testing date; identification of the product or sample tested (see EN 14778); a reference to this Technical Report; any deviation from this Technical Report; conditions and observations, e.g. unusual occurrences during the test procedure, which may affect the result; the test results as demonstrated in Table 1; if the 2 % difference between the total ma