EN ISO 5370:2023
(Main)Solid biofuels - Determination of fines content in pellets (ISO 5370:2023)
Solid biofuels - Determination of fines content in pellets (ISO 5370:2023)
This document specifies a method for determining the amount of material passing through a sieve with 3,15-mm-diameter round holes. It is intended for use in all applications (e.g. laboratories, production sites, field locations) where the measurement of fines is required.
Biogene Festbrennstoffe - Bestimmung des Feinanteils in Pellets (ISO 5370:2023)
Dieses Dokument legt ein Verfahren zur Bestimmung der Materialmenge fest, die ein Rundlochsieb mit einer Lochweite von 3,15mm Durchmesser passiert. Es ist für alle Einsatzbereiche (z.B. Laboratorien, Produktions
stätten, Feldstandorte) vorgesehen, bei denen die Messung des Feinanteils erforderlich ist.
Biocombustibles solides - Détermination de la teneur en fines des granulés (ISO 5370:2023)
Le présent document spécifie une méthode pour la détermination de la quantité de matériau passant à travers un tamis à trous ronds de 3,15 mm de diamètre. Il est destiné à être utilisé dans toutes les applications (par exemple: laboratoires, sites de production, emplacements sur le terrain) où la mesure des fines est requise.
Trdna biogoriva - Določanje vsebnosti drobnih snovi v peletih (ISO 5370:2023)
Ta mednarodni standard določa metodo za določanje količine materiala, ki gre skozi sito z okroglimi luknjami premera 3,15 mm. Namenjen je uporabi v vseh aplikacijah (npr. v laboratorijih, proizvodnih obratih, na terenu), kjer se zahteva merjenje drobnih delcev.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-2023
Trdna biogoriva - Določanje vsebnosti drobnih snovi v peletih (ISO 5370:2023)
Solid biofuels - Determination of fines content in pellets (ISO 5370:2023)
Biogene Festbrennstoffe - Bestimmung des Gehaltes an Feingut in Pellets (ISO
5370:2023)
Biocombustibles solides - Détermination de la teneur en fines des granulés (ISO
5370:2023)
Ta slovenski standard je istoveten z: EN ISO 5370:2023
ICS:
75.160.40 Biogoriva Biofuels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 5370
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2023
EUROPÄISCHE NORM
ICS 27.190; 75.160.40
English Version
Solid biofuels - Determination of fines content in pellets
(ISO 5370:2023)
Biocombustibles solides - Détermination de la teneur Biogene Festbrennstoffe - Bestimmung des Gehaltes an
en fines des granulés (ISO 5370:2023) Feingut in Pellets (ISO 5370:2023)
This European Standard was approved by CEN on 17 December 2022.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 5370:2023 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 5370:2023) has been prepared by Technical Committee ISO/TC 238 "Solid
biofuels" in collaboration with Technical Committee CEN/TC 335 “Solid biofuels” the secretariat of
which is held by SIS.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by August 2023, and conflicting national standards shall
be withdrawn at the latest by August 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 5370:2023 has been approved by CEN as EN ISO 5370:2023 without any modification.
INTERNATIONAL ISO
STANDARD 5370
First edition
2023-01
Solid biofuels — Determination of
fines content in pellets
Biocombustibles solides — Détermination de la teneur en fines des
granulés
Reference number
ISO 5370:2023(E)
ISO 5370:2023(E)
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 5370:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 2
6 Sample preparation .3
6.1 Sample size reduction . 3
6.2 Size of the test portion . 3
7 Procedure .4
7.1 Preparing of the sieving equipment . 4
7.2 Sieving . 4
8 Calculations . 5
8.1 Proportion of fines . 5
8.2 Quality control . 5
9 Performance characteristics . 5
10 Test report . 5
Annex A (informative) Determination of coarse pellet fines (CPF) . 6
Annex B (informative) Determination of fractions of fines smaller than 3,15 mm .11
Annex C (informative) Performance data .13
Annex D (informative) Research study data .15
Bibliography .18
iii
ISO 5370:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 238, Solid biofuels, in collaboration with
the European Committee for Standardization (CEN) Technical Committee CEN/TC 335, Solid biofuels, in
accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
ISO 5370:2023(E)
Introduction
This document specifies a method for manual determination of the fines content in pellets. The fines
content is defined as the percentage in mass of material below 3,15 mm in size (measured with a round
hole perforated metal plate sieve according to ISO 3310-2). The fines content is an important parameter
since excessive amounts of fines in consignments of pellets can cause problems either in transportation
systems or during combustion, or both. It also can cause health problems if the dust is inhaled and
it increases the risk of dust explosions. Many of these problems are connected to the tendency of
stratification of fines caused by any movement of the pellets.
Annex A describes a procedure for determining the amount of coarse pellet fines
(3,15 mm ≤ CPF < 5,6 mm). The determination of the amounts of smaller fines particles, for example the
fractions < 1 mm and < 0,5 mm, is given in Annex B.
NOTE 1 The upper limit of 5,6 mm for CPF was chosen because a sieve with an aperture diameter of 5,6 mm is
the standard commercial sieve with the next-smallest aperture diameter after 6 mm, which corresponds to the
diameter of the standard pellet size. When conducting the procedure for CPF as outlined in Annex A, additional
CPF are created as a result of the sieving procedure. Test results are therefore indicative and best used for
comparative purposes rather than treated as CPF originally present in the sample.
NOTE 2 This document will replace ISO 18846.
v
INTERNATIONAL STANDARD ISO 5370:2023(E)
Solid biofuels — Determination of fines content in pellets
1 Scope
This document specifies a method for determining the amount of material passing through a sieve with
3,15-mm-diameter round holes. It is intended for use in all applications (e.g. laboratories, production
sites, field locations) where the measurement of fines is required.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3310-1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth
ISO 3310-2, Test sieves — Technical requirements and testing — Part 2: Test sieves of perforated metal
plate
ISO 16559, Solid biofuels — Vocabulary
ISO 18135, Solid biofuels — Sampling
ISO 21945, Solid biofuels — Simplified sampling method for small scale applications
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16559 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
coarse pellet fines
CPF
particles with a size ranging from ≥ 3,15 mm to < 5,6 mm resulting from breakage of pellets during
production or handling
Note 1 to entry: The fraction of CPF contains all particles which pass through a sieve with 5,6-mm-diameter
round holes and which are retained on a sieve with 3,15-mm-diameter round holes (see ISO 3310-2).
4 Principle
A test portion is subjected to manual screening by means of a sieve with 3,15-mm-diameter round
holes while utilizing specific test conditions (e.g. a template is used to guide the movement of the sieve,
rotational speed is specified, the number of rotations is dependent on the nature of the material being
tested) and the mass of the material passing through the sieve is determined as a mass percentage of
the total mass of the test portion.
ISO 5370:2023(E)
5 Apparatus
5.1 Sieve template, as illustrated in Figure 1, consisting of a (14 ± 2) mm-thick wooden board with a
hole cut in the centre to receive the sieve with collecting pan, all mounted on a base panel with the same
size dimensions. The sieve template is for guiding the sieve during the screening process to ensure
consistent motion of the sieve. The inner circle should have a smooth surface to enable smooth circular
movements of the sieve with the collecting pan within the template. The template diameter is based on
a factor of 1,4 multiplied by the sieve diameter.
The diameter of the sieve and the template, the target size of the sub-portion used for a single screening
operation and the rotational speed are given in Table 1.
Table 1 — Diameter of sieve and the template, size of the sub-portion and rotational speed
Mass of sub-portion for a single
Inner diame- Approximate rota-
sieving procedure
Sieve diameter
ter of template tional speed
Recommended Range
mm
mm r/min
g g
400 Recommended 560 500 300 to 600 80
sieve diameter
300 Alternative sieve 420 280 170 to 340 95
diameters
450 630 630 380 to 760 77
The template shall be secured to the workplace (table) by, for example, clamps.
a) Top view b) Cross-section
Key
A template, with a wooden base
B sieve
C collecting pan
D workplace, table
Figure 1 — Sieving apparatus with template
To facilitate operation, a lubricant may be used to improve the sliding properties of the collection pan in
the template, such as graphite powder or silicon lubricant. Additionally, roller tables may be used.
5.2 Circular sieve with 3,15-mm-diameter round holes, and aperture geometry in accordance
with ISO 3310-2. A sieve with a diameter of 400 mm is recommended. Other sieve diameters within
the range of 300 mm to 450 mm may be used, but it is important to make sure the sieving criteria is
adjusted for the specific sieve to be used (see Table 1). The frame of the sieve shall have a height which
allows for free movement of the sample without losing material during the sieving process.
ISO 5370:2023(E)
5.3 Sieve with 5,6-mm-diameter round holes. If coarse pellet fines (3,15 mm ≤ CPF < 5,6 mm) are
determined in accordance with Annex A, the circular sieve shall have round holes with a diameter of
5,6 mm and aperture geometry in accordance with ISO 3310-2. All other requirements are given in 5.2.
5.4 Sieves, with metal wire cloth having aperture sizes smaller than 3,15 mm. If fines fractions
smaller than 3,15 mm, for example < 1 mm or < 0,5 mm, are determined in accordance with Annex B,
the circular or rectangle sieves shall have an aperture geometry in accordance with ISO 3310-1 and
shall have a minimum effective sieve area of 250 cm .
5.5 Collecting pan, for collection of material passing through the sieve, with the same diameter as
the sieve.
5.6 Weighing container(s), of adequate size for weighing of the fractions. The collecting pan may
also be used as a weighing container.
5.7 Balance, with suitable capacity to weigh the total mass of the sample plus any container used to
hold the sample, capable of reading to the nearest 0,1 g.
5.8 Metronome or stopwatch, for confirmation of the rotational speed when performing the sieving
procedure.
NOTE Use of a simple metronome, such as a mobile phone app, has been shown to be a convenient method for
speed control.
6 Sample preparation
6.1 Sample size reduction
The laboratory sample used for the determination of the fines content shall be obtained in accordance
with ISO 18135 or ISO 21945. The sampling strategy shall be such that special provisions are taken
regarding the tendency for stratification of the fines in a consignment of pellets. For example, the
entire quantity of pellets in a bag shall be taken as the laboratory sample. Due to the special provisions
necessary regarding sampling for fines determination, the combined (raw) sample can end up being very
large. The combined sample may be divided into one or more smaller test portions using appropriate
methods of subdivision as outlined in ISO 14780 (e.g. a riffle box). For the test portion used for the
determination of fines content, the minimum mass given in 6.2 shall be considered.
NOTE In bulk handling of large volumes of pellets there is often a risk of stratification of materials in storage
bins. There is also the risk of incremental variations of fines in volumes of pellets due to batch-wise operation
during transportation by rail carriages, trucks and ocean-going vessels.
6.2 Size of the test portion
The size of the test portion shall be selected in relation to pellet diameter as given in Table 2.
Table 2 — Minimum mass of test portion depending on the pellet diameter
Minimum size of a test
Pellet diameter
portion
mm
kg
6 to 8 3
> 8 (up to 25) 5
ISO 5370:2023(E)
7 Procedure
7.1 Preparing of the sieving equipment
The template shall be placed on a table or work bench as shown in Figure 1. It shall be fixed, for example
with clamps, to ensure regular circular movements of the combination of sieve and collecting pan.
The sieve is placed on top of the collecting pan and together they are placed inside the template against
the edge.
This sieving procedure is based on the use of a 400-mm-diameter sieve and a template of 560 mm inner
diameter. When using a sieve with another size, the appropriate template shall be used.
7.2 Sieving
Weigh the test portion to the nearest 0,1 g and record the mass.
Place a first sub-portion on the sieve. The target mass of the sub-portion is 500 g but it is also permitted
to use a mass within the range given in Table 1. If a sieve with another diameter is being used, see
Table 1 for the size of sub-portions.
Sieve the sub-portion using circular rotations within the template at a rate of approximately 80 rotations
per minute (r/min). At this speed (10 ± ¼) rotations will take approximately 7,5 s and (20 ± ¼) rotations
will take approximately 15 s. Technicians performing the test procedure the first time should adjust
their rotational speed in pre-tests using a stopwatch or a metronome. Rotational speed can also be
checked from time to time using the stopwatch or the metronome. For other sieve sizes, an appropriate
rotational speed shall be used; values for sieves with a diameter of 300 mm and of 450 mm are given in
Table 1. In all cases, the rotational speed should be sufficient to maintain most of the pellets in motion.
Sieve rotations can be either clockwise or anticlockwise.
Empirical data for the sieving speed using sieves with a diameter of 400 mm and of 300 mm are given
in Annex D.
The total number of rotations will depend on the nature of the material being sieved and is given in
Table 3. The number of rotations will remain the same regardless of the sieve diameter being used.
Table 3 — Number of rotations for sieving procedure
Pellets to be sieved Number of rotations
Pellets made for residential or commercial use where
compliance limits for fines content is 1,0 % in mass 10 ± ¼
or less
Pellets made for commercial or industrial use where
20 ± ¼
compliance limits for fines content is > 1 % in mass
After completing the sieving of the sub-portion, transfer the coarse material retained on the sieve
to another container. The fines fraction can be left inside the collecting pan or, if desired, can be
transferred to a weighing container. Place the sieve back on the collecting pan, place both the collecting
pan and the sieve back into the template against the edge and place the next sub-portion on the sieve.
Repeat this sieving process until all sub-portions have been screened for fines.
Once the whole test-portion has been sieved, weigh the cumulated fines fraction (either in the tared
weighed collecting pan or in a separate weighing container) to the nearest 0,1 g. For quality control,
also weigh the cumulated coarse material that was retained on the sieve.
NOTE 1 The maximum mass of 600 g of a sub-portion allows the subsequent use of the sub-portion for the
determination of durability according to ISO 17831-1.
ISO 5370:2023(E)
NOTE 2 Sieving of pellets with low durability leads to formation of fines due to abrasion during sieving. The
tendency of an over-estimation of the fines content increases with decreasing mechanical durability of the
pellets.
8 Calculations
8.1 Proportion of fines
Calculate the percentage in mass of fines by dividing the mass of the cumulated fines fraction by the
mass of the test portion used for the sieving procedure and multiply by 100.
The result shall be given to the nearest 0,1 % in mass for reporting.
8.2 Quality control
Calculate the difference between the mass of the test portion and the total mass of the cumulated fines
fraction and the cumulated coarse material that was retained on the sieve and express the difference
in per cent of the mass of the test portion. If the difference is larger than 2 % in mass, the causes for the
deviation shall be investigated and the determination shall be repeated with a new test portion. If the
difference after repeated determination still exceeds 2 % of the mass of the test portion, the size of the
test portion and the difference in percentage mass shall be reported together with the fines content as
per 8.1.
If the amount of CPF is determined according to Annex A from the sample used in 7.2, then the mass of
cumulated CPF and the mass of cumulated coarse material that was retained on the sieve with 5,6-mm-
diam
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