1、BSI Standards Publication PD CEN/TR 15149-3:2014 Solid biofuels Determination of particle size distribution Part 3: Rotary screen methodPD CEN/TR 15149-3:2014 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of CEN/TR 15149-3:2014. It supersedes DD CEN/TS 15149-3
2、:2006 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee PTI/17, Solid biofuels. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions
3、of a contract. Users are responsible for its correct application. The British Standards Institution 2014. Published by BSI Standards Limited 2014 ISBN 978 0 580 73877 7 ICS 75.160.10 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was publish
4、ed under the authority of the Standards Policy and Strategy Committee on 30 November 2014. Amendments issued since publication Date 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 15149-3:2006 Engl
5、ish Version Solid biofuels - 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 r
6、otierendem Sieb This Technical 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
7、Macedonia, France, Germany, 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
8、 EUROPISCHES KOMITEE FR NORMUNG 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 15149-3:2014 CEN/TR 15149-3:2014 (E) 2 Contents Page
9、Foreword 3 Introduction .4 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 rota
10、ry sieving machine 11 Bibliography . 12 PD CEN/TR 15149-3:2014 CEN/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
11、elements of this document may 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
12、 European Free Trade Association. 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: Rota
13、ry screen method Technical 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
14、15149-3:2014 CEN/TR 15149-3:2014 (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 metho
15、d, by which the degree of overestimating 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
16、 suppliers and consumers based 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 15149-3:2014 CEN/TR 15149-3:2014 (E) 5 1 Scope This Technical Report specifies a method for the deter
17、mination of the size distribution 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, g
18、rain, etc. This document applies 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
19、 application. For dated references, 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 mois
20、ture content - Oven dry method 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 si
21、eve apertures of 3,15 mm and 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 defin
22、itions given in EN ISO 16559 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
23、the test a rotary sieving device 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 15149-3:2014 CEN/TR 15149-3:2014 (E) 6 ( 15 mm). The height (length) of each
24、of the 5 sieve rings is 400 mm 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. T
25、he inner surface of the drum shall 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 rotati
26、ons per minute. Due to both, inclination 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 ea
27、ch sieve cylinder. Large particles, 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 m
28、aterial flow direction 4 collecting 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 t
29、he sample material. It is recommended 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 (se
30、e Figure 1). 5.2 Balance. A balance capable of measuring the mass of the sample to be sieved to the nearest 0,1 g is required. PD CEN/TR 15149-3:2014 CEN/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 shal
31、l be 8 l and shall have been sampled 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
32、Sample preparation The sample shall 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 descr
33、ibed in EN 14780, the sample is 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 repor
34、ted concurrently with the particle 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
35、 constant feeding rate of 1 l per 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
36、is done by hand, the sample should 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 (mo
37、re than 8 l) is processed, the 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, th
38、e sieve shall be stopped and the 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 n
39、et material in each fraction with 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 comput
40、ing the median particle size or for illustrating the results in a cumulative size distribution curve. PD CEN/TR 15149-3:2014 CEN/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 particle
41、s in the smaller size fractions. 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 hol
42、es of the first cylinder ring, is 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
43、 overall percentage of each class. This procedure is demonstrated in Table 1. PD CEN/TR 15149-3:2014 CEN/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
44、, in grams Mass of fraction in subsample 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 81
45、6 4th Collecting pan 1645 5th Collecting 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
46、mm) Length of longest particle overall, 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
47、 mass of all fractions as indicated 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
48、 the result still deviates more than 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
49、:2014 CEN/TR 15149-3:2014 (E) 10 10 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 t
