Solid biofuels - Safety of solid biofuel pellets - Safe handling and storage of wood pellets in residential and other small-scale applications (ISO 20023:2018)

This International Standard provides principles and requirements for safe handling and storage of wood pellets in residential and other small-scale applications. It covers the supply chain from the final loading point of the bulk transport to the end-user storage and specific requirements for the bulk transport. It also covers the design and construction of pellet storage systems. This standard addresses risks of fires, dust explosions, off-gassing and other health risks. It is applicable to wood pellets in accordance with ISO 17225-2.

Biogene Festbrennstoffe - Sicherheit von biogenen Festbrennstoffen - Sicherer Umgang und Lagerung von Holzpellets in häuslichen- und anderen kleinen Feuerstätten (ISO 20023:2018)

Dieses Dokument enthält die grundlegenden Prinzipien und Anforderungen für die sichere Handhabung und Lagerung von Holzpellets in häuslichen und anderen kleinen Feuerstätten. Es erfasst die Lieferkette vom Beladen der Lieferfahrzeuge einschließlich der Anforderungen an Lieferfahrzeuge bis zu den Anschlüssen an die Lagerstätte der Endverbraucher sowie den Lieferprozess. Zudem erfasst es die Auslegung und Konstruk¬tion von Pelletlagerungssystemen. Dieses Dokument behandelt die Gefahr durch Feuer und Staubexplosionen, das Risiko der Ausgasung, der Sauerstoffarmut, von Schäden an Anlagen und Gebäuden durch das Aufquellen von Pellets, sowie weitere Gesundheitsrisiken. Es gilt für Holzpellets nach ISO 17225 2.

Biocombustibles solides - Sécurité des granulés de biocombustible solide - Manutention et stockage en toute sécurité des granulés de bois dans des applications résidentielles et autres applications à petite échelle (ISO 20023:2018)

Le présent document fournit des principes et des exigences pour la manutention et le stockage en toute sécurité des granulés de bois dans les applications résidentielles et autres applications à petite échelle. Il couvre la chaîne d'approvisionnement à partir du chargement du camion de livraison, les exigences applicables aux camions de livraison, les jonctions avec le silo de l'utilisateur final et le processus de livraison. Il couvre également la conception et la construction des installations de stockage des granulés. Le présent document traite des risques d'incendie, d'explosion de poussières, de dégagement gazeux, de diminution de la teneur en oxygène, de dommages sur les appareils et bâtiments dus au gonflement des granulés, et des autres risques pour la santé. Il s'applique aux granulés de bois conformément à l'ISO 17225-2.

Trdna biogoriva - Varnost peletov trdnega biogoriva - Varno ravnanje in shranjevanje lesnih peletov za uporabo v stanovanjskih in drugih manjših napravah (ISO 20023:2018)

Ta mednarodni standard podaja načela in zahteve za varno ravnanje ter shranjevanje lesnih peletov za uporabo v stanovanjskih in drugih manjših napravah. Obravnava dobavno verigo od končnega mesta natovarjanja razsutega tovora do skladiščenja pri končnem uporabniku in določa posebne zahteve za prevoz razsutega tovora. Obravnava tudi zasnovo in konstrukcijo sistemov za shranjevanje peletov. Ta standard obravnava nevarnosti nastanka požarov, eksplozije prahu in hlapov organskih spojin ter druga tveganja za zdravje. Uporablja se za lesne pelete v skladu s standardom ISO 17225-2.

General Information

Status
Published
Public Enquiry End Date
02-May-2017
Publication Date
07-Jan-2019
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
19-Dec-2018
Due Date
23-Feb-2019
Completion Date
08-Jan-2019

Buy Standard

Standard
EN ISO 20023:2019 - BARVE
English language
58 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day
Draft
prEN ISO 20023:2017 - BARVE
English language
49 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 20023:2019
01-februar-2019
Trdna biogoriva - Varnost peletov trdnega biogoriva - Varno ravnanje in
shranjevanje lesnih peletov za uporabo v stanovanjskih in drugih manjših
napravah (ISO 20023:2018)
Solid biofuels - Safety of solid biofuel pellets - Safe handling and storage of wood pellets
in residential and other small-scale applications (ISO 20023:2018)
Biogene Festbrennstoffe - Sicherheit von biogenen Festbrennstoffen - Sicherer Umgang
und Lagerung von Holzpellets in häuslichen- und anderen kleinen Feuerstätten (ISO
20023:2018)
Biocombustibles solides - Sécurité des granulés de biocombustible solide - Manutention
et stockage en toute sécurité des granulés de bois dans des applications résidentielles et
autres applications à petite échelle (ISO 20023:2018)
Ta slovenski standard je istoveten z: EN ISO 20023:2018
ICS:
75.160.40 Biogoriva Biofuels
SIST EN ISO 20023:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN ISO 20023:2019

---------------------- Page: 2 ----------------------

SIST EN ISO 20023:2019


EN ISO 20023
EUROPEAN STANDARD

NORME EUROPÉENNE

December 2018
EUROPÄISCHE NORM
ICS 27.190; 75.160.40
English Version

Solid biofuels - Safety of solid biofuel pellets - Safe
handling and storage of wood pellets in residential and
other small-scale applications (ISO 20023:2018)
Biocombustibles solides - Sécurité des granulés de Biogene Festbrennstoffe - Sicherheit von biogenen
biocombustible solide - Manutention et stockage en Festbrennstoffen - Sicherer Umgang und Lagerung von
toute sécurité des granulés de bois dans des Holzpellets in häuslichen- und anderen kleinen
applications résidentielles et autres applications à Feuerstätten (ISO 20023:2018)
petite échelle (ISO 20023:2018)
This European Standard was approved by CEN on 5 October 2018.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey 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
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 20023:2018 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST EN ISO 20023:2019
EN ISO 20023:2018 (E)
Contents Page
European foreword . 3

2

---------------------- Page: 4 ----------------------

SIST EN ISO 20023:2019
EN ISO 20023:2018 (E)
European foreword
This document (EN ISO 20023:2018) 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 June 2019, and conflicting national standards shall be
withdrawn at the latest by June 2019.
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.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 20023:2018 has been approved by CEN as EN ISO 20023:2018 without any modification.


3

---------------------- Page: 5 ----------------------

SIST EN ISO 20023:2019

---------------------- Page: 6 ----------------------

SIST EN ISO 20023:2019
INTERNATIONAL ISO
STANDARD 20023
First edition
2018-10
Solid biofuels — Safety of solid biofuel
pellets — Safe handling and storage of
wood pellets in residential and other
small-scale applications
Biocombustibles solides — Sécurité des granulés de biocombustible
solide — Manutention et stockage en toute sécurité des granulés
de bois dans des applications résidentielles et autres applications à
petite échelle
Reference number
ISO 20023:2018(E)
©
ISO 2018

---------------------- Page: 7 ----------------------

SIST EN ISO 20023:2019
ISO 20023:2018(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved

---------------------- Page: 8 ----------------------

SIST EN ISO 20023:2019
ISO 20023:2018(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General terms . 1
3.2 Terms related to transportation and delivery . 2
3.3 Terms related to storage . 3
4 General . 3
4.1 Product requirements . 3
4.2 Hazards associated with amounts of pellets ≤100 t . 3
4.3 General requirements for storage and handling of pellets . 4
5 Requirements for safe transport and delivery of pellets . 4
5.1 General . 4
5.2 Requirements for bulk delivery by blower trucks . 5
5.2.1 Transport vehicles and their operation . 5
5.2.2 Filling end-user storage systems . 6
5.3 Pellets delivered in bulk tipped into troughs or bunkers . 8
5.4 Pellets delivered in big bags . 8
5.5 Pellets delivered in small bags on pallets . 8
6 Requirements for bulk storage systems . 8
6.1 General requirements . 8
6.1.1 Location of pellet store . 8
6.1.2 Quality control of installation . 9
6.1.3 Construction requirements . 9
6.1.4 Measures to reduce the accumulation of fines . 9
6.1.5 Protection against moisture and water . 9
6.1.6 Prevention of dust movement . 9
6.1.7 Noise protection . 9
6.1.8 Installation .10
6.1.9 Fire protection .10
6.1.10 Explosion prevention .10
6.1.11 Protection and measures against burn-back and back gassing . .10
6.1.12 Extraction systems .11
6.1.13 Fill connectors and piping .11
6.1.14 Electrical outlet for suction fan .12
6.1.15 Ventilation .12
6.1.16 Safety instructions .15
6.1.17 Access to storage .15
6.2 Individual custom-made pellet stores .15
6.2.1 Construction requirements .15
6.2.2 Fill connectors .17
6.2.3 Impact protection mat .18
6.2.4 Sloping floor .18
6.2.5 Access hatch/door to pellet store .18
6.3 Pre-fabricated storage systems .19
6.3.1 General.19
6.3.2 Requirements regarding the site, indoor systems .20
6.3.3 Requirements regarding the siting of outdoor installations .20
6.3.4 Ground connection (earth) .20
6.3.5 Filling instructions .20
6.3.6 Fabric store .20
© ISO 2018 – All rights reserved iii

---------------------- Page: 9 ----------------------

SIST EN ISO 20023:2019
ISO 20023:2018(E)

6.3.7 Underground store .21
7 Health protection aspects .21
7.1 Entering a pellet store .21
7.1.1 General.21
7.1.2 Requirements for small pellet stores up to 15 t .22
7.1.3 Requirements for pellet stores >15 t and/or underground stores .22
7.2 Stationary CO monitors .22
7.3 Equipment used in stores .23
Annex A (informative) Hazards associated with pellets .24
Annex B (informative) Model calculation for different cases of store ventilation .30
Annex C (informative) Examples for store designs .34
Annex D (normative) Minimum requirements of a hand-over document .42
Annex E (informative) Example of a checklist for filling of store .46
Bibliography .48
iv © ISO 2018 – All rights reserved

---------------------- Page: 10 ----------------------

SIST EN ISO 20023:2019
ISO 20023:2018(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.
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.
© ISO 2018 – All rights reserved v

---------------------- Page: 11 ----------------------

SIST EN ISO 20023:2019
ISO 20023:2018(E)

Introduction
There is a continuous global growth in production, storage, handling, bulk transport and use of solid
biofuels especially in the form of pelletized biofuels.
The specific physical and chemical characteristics of solid biofuels, their handling and storage can lead
to a risk of fire and/or explosion, as well as health risks such as intoxication due to exposure to carbon-
monoxide, asphyxiation due to oxygen depletion or allergic reactions.
There is a risk of injury or death associated with pellet storage, so safety measures shall be implemented.
The possibility of fire and explosion incidents is a clear indicator that safety needs to be prioritized,
first of all for human safety but also because interruptions in energy supply can have significant
consequences. The market confidence in solid biofuels as a secure energy source may be jeopardized
and financial losses due to business interruptions could occur. Difficulty to obtain insurance coverage
will also increase.
As part of the determination and the assessment of risks for solid biofuels, defined test methods
and standards are established or need to be developed. However, the ageing and degradation due to
handling and storage of solid biofuels in particular environments will affect the characteristics. The
consequence of this change of characteristics is that safety margins need to be established in relation to
the actual analysis results.
For small scale applications and handling of small quantities of pellets up to 100 t, requirements of this
standard support end-users not educated in safety aspects or requirements of solid biofuel handling.
Health risks are associated with the quality of the fuel and therefore controlling the fuel quality reduces
the risks, particularly of dust emissions. Logistics and the handling of the pellets play a major part in
maintaining quality and are therefore also addressed in this standard.
Generally, facilities at end users with a storage capacity <100 t are covered by this document and larger
1)
stores will be covered by ISO 20024 . However, storage capacity alone is not a good enough parameter
on which to decide which standard to apply. A trader or larger end user might have a number of small
storage facilities but may have a greater throughput of pellets during the entire year but with frequent
filling and reclaiming or packaging. Depending on the characteristics of a specific facility, all of the
principles covered in this document should be considered but all or only some parts of the systems/
equipment described in ISO 20024 will be relevant.
A competent assessor should have knowledge and experience commensurate with the complexity of the
facility (knowledge of solid biofuels is required) before selecting which standard and which clauses are
applicable to the facility being considered.
1)  Under preparation. Stage at the time of publication ISO/CD 20024:2018.
vi © ISO 2018 – All rights reserved

---------------------- Page: 12 ----------------------

SIST EN ISO 20023:2019
INTERNATIONAL STANDARD ISO 20023:2018(E)
Solid biofuels — Safety of solid biofuel pellets — Safe
handling and storage of wood pellets in residential and
other small-scale applications
1 Scope
This document provides principles and requirements for the safe handling and storage of wood pellets
in residential and other small-scale applications. It covers the supply chain from loading of the delivery
truck, requirements of delivery trucks, connections to the end-user's store and the delivery process.
It also covers the design and construction of pellet storage systems. This document addresses risks
of fires, dust explosions, off-gassing, oxygen depletion, damage to appliances and buildings through
swelling of pellets and other health risks. It is applicable to wood pellets according to ISO 17225-2.
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 16559, Solid biofuels — Terminology, definitions and descriptions
ISO 17225-2, Solid biofuels — Fuel specifications and classes — Part 2: Graded wood pellets
IEC 60529, Degrees of protection provided by enclosures (IP Code)
EN 13237, Potentially explosive atmospheres — Terms and definitions for equipment and protective systems
intended for use in potentially explosive atmospheres
3 Terms and definitions
For the purposes of this document, terms and definitions given in ISO 16559 and EN 13237, and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1 General terms
3.1.1
combustible dust
finely divided solid particles, with a particle size of 500 μm or less in nominal size, which may form
explosive mixtures with air at standard atmospheric pressure and temperatures
Note 1 to entry: This includes dust and grit as defined in ISO 4225.
Note 2 to entry: The term 'solid particles' is intended to address particles in the solid phase but does not preclude
a hollow particle.
[SOURCE: ISO/IEC 80079-20-2:2016, 3.1]
© ISO 2018 – All rights reserved 1

---------------------- Page: 13 ----------------------

SIST EN ISO 20023:2019
ISO 20023:2018(E)

3.1.2
fines
F
small sized particles in fuel below a certain pre-defined size, here less than 3,15 mm
Note 1 to entry: The amount of fines can be different after completion of production, bagging, transportation,
unloading, distribution etc.
[SOURCE: ISO 16559:2014, 4.90, modified — “usually” replaced by “here” to indicate exact limit.]
3.2 Terms related to transportation and delivery
3.2.1
bulk transport
pellets transported loose, typically in tippers, walking floor trucks, other trucks with closed cargo area
or blower trucks (3.2.2)
3.2.2
blower truck
vehicle with a pneumatic discharge system using compressed air
Note 1 to entry: Examples of blower trucks include silo-trucks and rotary feeder trucks.
3.2.3
silo truck
fully pneumatic blower truck (3.2.2) where pellets are loaded into special pressurised compartments
emptied by applying compressed air and using compressed air for pellet conveying
3.2.4
rotary feeder truck
truck where pellets are discharged by gravity via a rotary valve (or star valve) into the stream of
compressed air for pellet conveying
3.2.5
day hopper
hopper directly linked to the automatically stoked heating boiler
Note 1 to entry: Typically a day hopper holds a few days of pellet fuel up to 1 t. The filling of the hopper is a batch
operation.
3.2.6
closing cap
cap made of metal or plastic, which seals the connectors (3.2.7)
3.2.7
connector
permanently installed coupling made of aluminium-alloys or steel, with a gasket ring for pressure and
suction operation, which functions in the filling of the pellet store (3.3.2)
Note 1 to entry: There are different uses for connectors, such as filling and suction.
3.2.8
delivery hose
temporary connection between the pellet blower truck (3.2.2) and the fill connector of the pellet store
during the pneumatic delivery process
2 © ISO 2018 – All rights reserved

---------------------- Page: 14 ----------------------

SIST EN ISO 20023:2019
ISO 20023:2018(E)

3.3 Terms related to storage
3.3.1
sloping floor
construction in the store that allows the fuel to be fed by gravity to the conveying system
Note 1 to entry: The aim is to achieve storage that completely drains without any intervention.
3.3.2
pellet store
room, container or other place where pellets are stored by the end-user before combustion
Note 1 to entry: Pellet stores can be self-built or pre-fabricated.
3.3.3
small pellet store
pellet store with a capacity of less than 15 t
3.3.4
individual customized store
pellet store that is individual custom-made into a building often including existing structures like walls
Note 1 to entry: Individual customized stores may be self-built by end-users.
3.3.5
pre-fabricated store
storage system built by specialist companies, erected at the end-user's premises
3.3.6
fill pipe
connecting pipe, which connects the fill connector (3.2.7) with the pellet store
3.3.7
small bag
bag for pellets with a typical filling weight between 8 kg and 25 kg
3.3.8
big bag
flexible intermediate bulk container (FIBC) made of flexible fabric that is designed for storing and
transporting bulk materials with a capacity of 500 l and above
4 General
4.1 Product requirements
This document was developed to promote the safe handling, storage and combustion of pellets
conforming to the fuel properties of ISO 17225-2, Classes A1, A2 and B. If other fuel types are used the
principles contained herein might not apply.
A data sheet for wood pellets issued by the manufacturer/supplier may provide more specific
information with regards to the produc
...

SLOVENSKI STANDARD
oSIST prEN ISO 20023:2017
01-april-2017
Trdna biogoriva - Varnost peletov trdnega biogoriva - Varno ravnanje in
shranjevanje lesnih peletov za uporabo v stanovanjskih in drugih manjših
napravah (ISO/DIS 20023:2017)
Solid biofuels - Safety of solid biofuel pellets - Safe handling and storage of wood pellets
in residential and other small-scale applications (ISO/DIS 20023:2017)
Biogene Festbrennstoffe - Sicherheit von biogenen Festbrennstoffen - Sichere
Handhabung und Lagerung von Holzpellets in häuslichen- und anderen kleinen
Feuerstätten (ISO/DIS 20023:2017)
Biocombustibles solides - Sécurité des granulés de biocombustible solide - Manipulation
et stockage des granulés de bois en toute sécurité dans des applications résidentielles
ou d'autres à petite échelle (ISO/DIS 20023:2017)
Ta slovenski standard je istoveten z: prEN ISO 20023
ICS:
75.160.40 Biogoriva Biofuels
oSIST prEN ISO 20023:2017 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN ISO 20023:2017

---------------------- Page: 2 ----------------------
oSIST prEN ISO 20023:2017
DRAFT INTERNATIONAL STANDARD
ISO/DIS 20023
ISO/TC 238 Secretariat: SIS
Voting begins on: Voting terminates on:
2017-01-20 2017-04-13
Solid biofuels — Safety of solid biofuel pellets — Safe
handling and storage of wood pellets in residential and
other small-scale applications
Titre manque
ICS: 27.190; 75.160.40
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 20023:2017(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2017

---------------------- Page: 3 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved

---------------------- Page: 4 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(E)
Contents
Foreword. 5
Introduction . 6
1 Scope. 7
2 Normative references . 7
3 Terms and definitions . 7
3.1 General terms . 8
3.2 Terms related to transportation and delivery . 8
3.3 Terms related to storage. 9
4 General .10
4.1 Product requirements.10
4.2 Hazards associated with small amounts of pellets (< 100 t).10
4.3 General requirements for storage and handling of pellets .11
5 Requirements for safe transport and delivery of pellets .11
5.1 General.11
5.2 Requirements for bulk delivery by blower trucks.12
5.3 Pellets delivered in bulk tipped into troughs or bunkers.15
5.4 Pellets delivered in big bags.15
5.5 Pellets delivered in small bags on pallets .15
6 Requirements for bulk storage systems.16
6.1 General requirements .16
6.2 Custom-made pellet stores.22
6.3 Pre-fabricated storage systems .27
7 Health protection aspects .29
7.1 Entering a pellet store.29
© ISO/DIS 2017 All rights reserved 3

---------------------- Page: 5 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(E)
7.2 Stationary CO monitors .30
7.3 Equipment used in stores .30
Annex A (informative) Examples of explosion properties of wood dust .31
Annex B (informative) Hazards associated with pellets .32
Annex C (informative) Custom-made storage rooms .38
Annex D (informative) Example of a hand-over document .45
Annex E (informative) Example of a checklist for filling of store.47

4 © ISO/DIS 2017 All rights reserved

---------------------- Page: 6 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(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 committe e.
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. www.iso.org/directives
Attention is drawn to the possibility that some of the elements of this document may be the subj ect 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. 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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO's adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 238 Solid biofuels.
© ISO/DIS 2017 All rights reserved 5

---------------------- Page: 7 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(E)
Introduction
There is a continuous global growth in production, storage, handling, bulk transport and use of solid
biofuels especially in the form of pelletized biofuels.
The handling and storage of solid biofuels and their physical characteristics can lead to a risk of fire
and/or explosion, as well as health risks such as intoxication due to exposure to carbon-monoxide,
asphyxiation due to oxygen depletion or allergic reactions.
There is a risk of injury or death associated with pellet storage, so safety measures shall be
implemented. The possibility of fire and explosion incidents is a clear indicator that safety needs to be
prioritized, first of all for human safety but also because interruptions in energy supply can have
significant consequences. The market confidence in solid biofuels as a reliable en ergy source may be
jeopardized and financial losses due to business interruptions could occur. Difficulty to obtain
insurance coverage will also increase.
At the moment it is difficult for facility owners, logistics providers, equipment suppliers/manufacturers,
consultants, authorities and insurance providers to determine reasonable measures and an appropriate
level of protection due to a lack of harmonized standards and recommendations.
As part of the determination and the assessment of risks for solid biofuels, defined test methods and
standards are established or need to be developed. However, the ageing and degradation due to
handling and storage of solid biofuels in actual environments will affect the characteristics. The
consequence of this change of characteristics is that safety margins have to be established in relation to
the actual analysis results.
For small scale appliances and handling of small quantities of pellets up to 100 t requirements of the
standard support end-users not educated in safety aspects or requirements of solid biofuel handling.
Health risks are closely related with quality of the fuel and therefore controlling the fuel quality reduces
the risks, particularly of dust emissions. Logistics and the handling of the pellets play a major part
maintaining quality and are therefore also addressed in this standard.
6 © ISO/DIS 2017 All rights reserved

---------------------- Page: 8 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(E)
Solid biofuels — Safety of solid biofuel pellets — Safe handling and
storage of wood pellets in residential and other small-scale
applications
1 Scope
This document provides principles and requirements for the safe delivery and storage of wood pellets
in residential and other small-scale applications. It covers the supply chain from loading of the delivery
truck, requirements of delivery trucks, connections to the end-user's store and the delivery process. It
also covers the design and construction of pellet storage systems. This document addresses risks of
fires, dust explosions, off-gassing, oxygen depletion and other health risks. It is applicable to wood
pellets in accordance with ISO 17225-2.
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.
EN 13237, Potentially explosive atmospheres — Terms and definitions for equipment and protective
systems intended for use in potentially explosive atmospheres
ISO 16559, Solid biofuels — Terminology, definitions and descriptions
ISO 17225-2, Solid biofuels — Fuel specifications and classes — Part 2: Graded wood pellets
IEC 60529, Degrees of protection provided by enclosures (IP Code)
3 Terms and definitions
For the purposes of this document, terms and definitions given in EN 13237 and ISO 16559 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
 IEC Electropedia: available at http://www.electropedia.org/
 ISO Online browsing platform: available at http://www.iso.org/obp
© ISO/DIS 2017 All rights reserved 7

---------------------- Page: 9 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(E)
3.1 General terms
3.1.1
dust
fragmented material of small size passing a 500 µm sieve caused by a non-voluntary process as opposed
to powder which is normally manufactured to size
Note 1 to entry: There is no official definition of what constitutes dust in terms of physical size (see ISO 16559). In
this standard dust is determined by using sieves according to ISO 3310-1. The particle size of 500 µm has been
determined based on Gestis explosion database, see [21].
Note 2 to entry: In EN 12779 dust is defined as particles of wood emanating from processing at woodworking
machines. The particle size for dust is set to less than 0,5 mm. In general dust is often considered as particles
below 75 µm in diameter, which settle out under their own weight but which remain suspended for some ti me.
3.1.2
fines
F
small sized particles in fuel below a certain pre-defined size, usually less than 3,15 mm
Note 1 to entry: The amount of fines can be different after completion of production, bagging, transportation,
unloading, distribution etc.
[SOURCE: ISO 16559:2014, 4.90]
3.2 Terms related to transportation and delivery
3.2.1
bulk transport
pellets transported loose, typically in walking floor trucks, other trucks with closed cargo area or
blower trucks (3.10)
3.2.2
blower truck
vehicle with a pneumatic discharge system using compressed air
Note 1 to entry: Examples of blower truck include, silo-truck and rotary feeder truck
3.2.3
silo truck
fully pneumatic blower truck (3.9) were pellets are loaded into special pressurised compartments
emptied by applying compressed air and using compressed air for pellet conveying
3.2.4
rotary feeder truck
truck where pellets are discharged by gravity via a rotary valve into the stream of compressed air for
pellet conveying
8 © ISO/DIS 2017 All rights reserved

---------------------- Page: 10 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(E)
3.2.5
day hopper
hopper linked to the automatically stoked heating boiler
Note 1 to entry: Typically a day hopper holds a few days of pellet fuel up to 1 t. The filling of the hopper is a batch
operation.
3.2.6
closing cap
cap made of metal or plastic, which seals the connectors (3.5)
3.2.7
connector
solid coupling made of aluminium-alloys or steel, with a gasket ring for pressure and suction operation,
which functions in the filling of the pellet store (3.12)
Note 1 to entry: There are different uses for connectors, such as filling and suction.
3.2.8
delivery hose
temporary connection between the pellet blower truck (3.19) and the fill connector of the pellet store
during the pneumatic delivery process and/or connection between the suction fan and the suction
connector of the store
3.2.9
safety data sheet
SDS
document specifying the properties of a substance, its potential hazardous effects for humans and the
environment, and the precautions necessary to handle and dispose of the substance safely
[SOURCE: ISO 14937:2009, 3.12]
3.3 Terms related to storage
3.3.1
sloping floor
construction in the store that allows the fuel to be fed by gravity to the conveying system
Note 1 to entry: The aim is to achieve storage that completely without any intervention.
3.3.2
pellet store
room, container or other place where pellets are stored by the end-user before combustion
Note 1 to entry: Pellet stores can be self-built or pre-fabricated
3.3.3
small pellet store
pellet store with a capacity of less than 15 t
© ISO/DIS 2017 All rights reserved 9

---------------------- Page: 11 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(E)
3.3.4
customized store
pellet store that is custom-made into a building often including existing structures like walls
Note 1 to entry: Customized stores may be self-built by end-users.
3.3.5
pre-fabricated store
storage system built by specialist companies, erected at the end-user's premises
3.3.6
storage container
fully enclosed container that is built independently of the building structure
Note 1 to entry: Storage containers can be made of materials permeable or impermeable to air such as metal,
concrete, plastics, wood or textiles.
3.3.7
fill pipe
connecting pipe of metal, which connects the fill connector with the pellet store
3.3.8
small bag
bag for pellets with a typical filling weight between 8 kg and 25 kg
3.3.9
big bag
flexible intermediate bulk container (FIBC) made of flexible fabric that is designed for storing and
transporting bulk materials with a capacity of 500 l and above
4 General
4.1 Product requirements
For residential and other small scale appliances only pellets according to ISO 17225-2 class A1, A2 or B
shall be used to guarantee safe handling, storage and combustion of pellets.
Pellets of different diameters or qualities shall not be mixed.
If there is a safety data sheet (SDS) for wood pellets issued by the manufacturer/supplier it may provide
more specific information with regards to the product delivered, quality, safety and health aspects
during handling and storage.
4.2 Hazards associated with small amounts of pellets (< 100 t)
Pellets react in their environment in different ways, especially with air and moisture and they are also
sensitive to mechanical stress. To avoid hazards it is important to store and handle pellets accordingly.
It is difficult to describe in detail all variables that might affect the pellets in practise, the technical
background and potential hazards are summarized in this clause for the most important hazards such
as:
10 © ISO/DIS 2017 All rights reserved

---------------------- Page: 12 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(E)
— emissions of volatile compounds and oxygen depletion,
— backflow of flue gases,
— fines and dust,
— uncontrolled ignition and smouldering,
— decomposition, and
— swelling.
More information concerning the listed hazards is compiled in informative Annex B.
4.3 General requirements for storage and handling of pellets
All handling and transport equipment shall be designed to minimise damage to the pellets. Abrasion of
pellets and consequential formation of fines shall be minimized.
Dust emissions to the environment shall be kept as low as possible. Fines and dust accumulate on flat
and inclined surfaces. These surfaces and other places where fines may accumulate shall be minimized.
Unavoidable areas where fines may accumulate shall be cleaned regularly, see 6.1.3.
Accumulation of carbon monoxide (CO) and volatiles in closed storage facilities shall be avoided by
proper ventilation of the facilities.
Wood pellets shall be protected against humidity and moisture. They shall be kept dry at all times.
All transport systems, including vehicles, conveyors and storage facilities shall be thoroughly cleaned
from previously handled products except when used for the same dimension and quality of pellets. .
NOTE Requirements for large storage facilities (> 100 t), packing and loading systems are provided in
ISO/CD 20024.
5 Requirements for safe transport and delivery of pellets
5.1 General
The requirements will differ depending on the type of delivery to the end-user:
— Bulk pellets for residential and other small-scale applications are typically delivered by blower
trucks. Requirements for this type of delivery, see 5.2.
— If bulk pellets are delivered by tippers or walking floor trucks and are unloaded at the end-
customer into a trough or a bunker, see 5.3.
— If other vehicles are used for bulk transport the suitability of the transport system shall be
evaluated.
— Pellets delivered in big bags, see 5.4
— Pellets delivered in small bags, see 5.5
© ISO/DIS 2017 All rights reserved 11

---------------------- Page: 13 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(E)
In all cases the pellets shall be protected against moisture (e.g. rain, snow or condensate) throughout
the transportation process as well as during loading and unloading.
Loading of trucks is only permitted when the pellet temperature is less than 40 °C. Heating of pellets in
the truck shall be minimized e.g. by using bright/reflective surface on the outside of the truck. Heating
can also be caused by using hot compressed air, which raises the temperature of the pellets.
The specification of the pellets shall be in accordance with ISO 17225-2 and shall be stated on all
delivery documentation and invoices.
All pellet handling areas shall be strictly non-smoking areas and have no naked flames.
5.2 Requirements for bulk delivery by blower trucks
5.2.1 Transport vehicles and their operation
To help the understanding of the following paragraphs, see Figure 1.
8
2
7
3
6
1
5
4

Figure 1 — Operating principle of the pneumatic delivery process using a silo truck.
Key
1  compressor 5  delivery hose
2  pressurisation of silo compartment 6  end-user’s pellet store
3  pressure gauge measures pressure in the 7  suction fan with filter sock to extract the
discharge pipe or in the silo compartment blower air and create a slightly negative pressure
in the pellet store
4  coupling on delivery vehicle
8  exhaust air
Mechanical damage of pellets caused by transport vehicles shall be minimized. Blower trucks shall be
equipped with a low abrasion blowing feed system. Low abrasion may be obtained by using coated
hoses. Sharp edges between hoses shall be avoided. The trucks should be equipped with a compressor
that provides air for blowing the pellets. Where required, blower trucks shall have a mobile fan to
extract the supply air from the storage facility during the delivery. Explosion protection for the mobile
fan is not required. The capacity of this suction fan shall exceed the capacity of the blowing system of
the vehicle. The extracted air shall be filtered(e.g. by fabric filter) to limit dust emissions to the
environment. The connected filter bag shall be checked for fouling and shall be protected from rain or
12 © ISO/DIS 2017 All rights reserved

---------------------- Page: 14 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(E)
be made from water resistant materials in order to ensure a permanent negative pressure in the pellet
store during the delivery process.
Some pre-fabricated stores do not need suction of the blowing air. Filling instructions provided by the
manufacturer of these stores shall be followed. Where no suction is required, the blowing air (up to
1500 m³/h) has to exit through windows, doors or other openings, so that the pressure in the room
where the pellet store is located does not increase significantly. Openings should have a size of at least
400 cm², see 6.1.10.
A blower truck shall be constructed so that the increase in fines is as low as possible. While testing the
suitability of a truck the increase of fines shall be less than 2 % and be tested using test conditions i.e.
using pellets with a mechanical durability of 98,5 % (± 0,3 %), a distance between the end of the tube
and a wall of 3 m with an impact mat 20 cm in front of the rear wall, the hose shall be 20 m long with
one 45° bend and a mass flow of 15 t/h (±1 t). The minimum quantity of fuel to be blown shall be 500
kg.
The actual fines content in the end-user's store depends on many additional factors to those during
testing (e.g. impact of driver/operating staff competence, blowing distance, height differences, bends,
construction and dimensions of the pellet store) and can exceed these 2 % increase expected for the
transportation vehicle testing.
Blower trucks should carry 30 m filling hoses as standard equipment. Locally used reducing and
connecting couplings should be part of the equipment on board the truck. The hose couplings shall be
free from sharp edges pointing in the direction opposite to the pellet flow. Only conductive delivery
hoses shall be used for the filling. Where the delivery hoses have a coating, the breakdown voltage shall
6
be below 4 kV. The delivery and vent hoses shall be dissipate static (earth leakage resistance RE << 10
Ω). Hoses shall be marked or be clearly visible when crossing traffic areas like sidewalks or bicycle path.
The delivery vehicle shall be equipped with an earthing system. Blower truck doing part deliveries to
end-users shall be equipped with calibrated certified on-board weighing system.
The truck storage cells shall be tightly shut immediately after loading the truck.
Only trucks properly operated, maintained and with well-kept blowers may be deployed. Storage cells,
hoses, fans, filters and other equipment shall be clean and shall be inspected regularly by the operating
staff according to the manufacturer’s instructions and good practice.
In difficult delivery situations where high temperatures can cause problems such as long distances
between the truck and fill connector and/or high ambient temperatures (> 30 °C), the delivery vehicles
should use cool air. This can be achieved by organizational measures (e.g. delivering in the cold early
morning) or technical measures (e.g. compressor cooler).
5.2.2 Filling end-user storage systems
There are two options when filling of a pellet store is allowed:
a) When the customer is on-site or deliverer has been provided with access:
— if required by the filling instructions of the manufacturer, the customer shall turn off the
combustion system in appropriate time before the delivery of the pellets. This needs to
be confirmed by the customer before delivery.
© ISO/DIS 2017 All rights reserved 13

---------------------- Page: 15 ----------------------
oSIST prEN ISO 20023:2017
ISO/DIS 20023:2017(E)
— the exact period of time before the delivery takes place should be given in the boiler
instructions.
— the driver has to make sure that the turn-off time meets the requirements.
b) When the customer is absent:
— the customer gives a written instruction that it is allowed to be filled without turning the
boiler off and the delivery should go ahead
— Where the delivery operative has no information on the length of time the boiler has
been turned off and there is no knowledge of written instruction from the end-user to
carry out the delivery operative the pellet supplier shall not fill the pellet store.
To help the understanding of the described options when filling a pellet store, see Figure 2.

Figure 2 — Filling of end-user store
Before filling an end-user pellet store a checklist shall be filled in by the delivery staff, see an example of
a checklist in Annex E. The checklist shall include at least the following information:
— Boiler switched off YES/NO/ UNKNOWN. If "no" or "unknown" a written instruction from the end-
user to carry out the delivery shall be provided. If there is no instruction and there is no
confirmation of the boiler state (on/off/unknown) no delivery shall be performed.
— Pellet store inspected YES/NO/PARTIALLY
— Suction fan used YES/NO
— Nature and estimated amount of remaining pellets in the store, if possible
14 © ISO/DIS 2017 All rights reserved

---------------------- Page: 16 --------
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.