EN 15188:2020
(Main)Determination of the spontaneous ignition behaviour of dust accumulations
Determination of the spontaneous ignition behaviour of dust accumulations
This European Standard specifies analysis and evaluation procedures for determining self-ignition temperatures (TSI) of combustible dusts or granular materials as a function of volume by hot storage experiments in ovens of constant temperature. The specified test method is applicable to any solid material for which the linear correlation of lg (V/A) versus the reciprocal self-ignition temperature 1/TSI (with TSI in K) holds (i.e. not limited to only oxidatively unstable materials).
This European Standard is not applicable to the ignition of dust layers or bulk solids under aerated conditions (e.g. as in fluid bed dryer).
This European Standard shall not be applied to dusts like recognised explosives that do not require atmospheric oxygen for combustion, nor to pyrophoric materials.
NOTE Because of regulatory and safety reasons "recognised explosives" are not in the scope of this European Standard. In spite of that, substances which undergo thermal decomposition reactions and which are not "recognised explosives" but behave very similarly to self-ignition processes when they decompose are in the scope. If there are any doubts as to whether the dust is an explosive or not, experts should be consulted.
Bestimmung des Selbstentzündungsverhaltens von Staubschüttungen
Dieses Dokument legt Prüf- und Auswerteverfahren zur Bestimmung der Selbstentzündungstemperaturen (TSI) brennbarer Stäube oder Schüttgüter als Funktion des Volumens fest. Das geschieht durch Warmlagerungsuntersuchungen in Öfen bei konstanter Ofentemperatur. Das spezifische Prüfverfahren ist auf jeden Feststoff anwendbar, für den die Theorie der Wärmeexplosion nach A.2 gilt (d. h. nicht begrenzt auf ausschließlich oxidativ instabile Stoffe).
Die spezifische Prüfung ist auf jeden Staub oder jedes Schüttgut anwendbar, das primär mit Luftsauerstoff reagiert. Aus Sicherheitsgründen wird diese Prüfung nicht mit Stoffen durchgeführt, die mit festen/flüssigen Oxidantien gemischt sind (z. B. Schießpulver, Thermit, mit flüssigem Sauerstoff imprägniertes Holz) oder mit Stoffen, bei denen heftige nicht oxidative Reaktionen entstehen könnten (z. B. Peroxide, Explosivstoffe). Jedoch dürfen im Einzelfall einige Arten von Stoffen geprüft werden, bei denen nicht oxidative Reaktionen entstehen können (z. B. nicht heftige exotherme Zersetzungsreaktionen), vorausgesetzt, dass zusätzliche Sicherheitsvorkehrungen getroffen werden. Bei Zweifeln über Gefahren aufgrund der Eigenschaften des zu untersuchenden Stoffes (z. B. ob er toxisch oder explosiv ist), wird der Rat eines Expertes eingeholt.
Dieses Dokument ist nicht anzuwenden für die Entzündung von Staubschichten oder Schüttungen unter durchlüfteten Bedingungen (wie z. B. in einem Fließbett-Trockner).
Détermination de l'aptitude à l'auto-inflammation des accumulations de poussières
Le présent document spécifie des modes opératoires d’analyse et d’évaluation permettant de déterminer les températures d’auto-inflammation (TAI) de poussières combustibles ou de matériaux granulaires en fonction de leur volume par des essais en étuve isotherme dans des étuves à température constante. La méthode d’essai spécifiée s’applique à tout matériau solide pour lequel la théorie de l’explosion thermique, selon l’Article A.2, se vérifie (c’est-à-dire que son applicabilité ne se limite pas aux seuls matériaux instables par oxydation).
L’essai spécifié s’applique à toute poussière ou tout matériau granulaire réagissant principalement avec l’oxygène de l’air. Pour des raisons de sécurité, cet essai ne doit pas être utilisé avec des matériaux mélangés à des oxydants solides/liquides (tels que de la poudre noire, des thermites ou du bois imprégné d’oxygène liquide) ou des matériaux pouvant subir de violentes réactions non oxydantes (par exemple, peroxydes, explosifs). Certains types de matériaux subissant des réactions non oxydantes (telles que des réactions de décomposition exothermiques non violentes) peuvent toutefois être soumis à essai au cas par cas, à condition de prendre des mesures de sécurité supplémentaires. En cas de doute concernant l’existence d’un danger lié aux propriétés du matériau d’essai (toxiques ou explosives, par exemple), il convient de consulter l’avis d’experts.
Le présent document n’est pas applicable à l’inflammation des couches de poussière ou des solides en vrac dans des conditions aérées (par exemple, dans un sécheur en lit fluidisé).
Določanje lastnosti samovžiga usedlih plasti prahu
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-2021
Nadomešča:
SIST EN 15188:2007
Določanje lastnosti samovžiga usedlih plasti prahu
Determination of the spontaneous ignition behaviour of dust accumulations
Bestimmung des Selbstentzündungsverhaltens von Staubschüttungen
Détermination de l'aptitude à l'auto-inflammation des accumulations de poussières
Ta slovenski standard je istoveten z: EN 15188:2020
ICS:
13.220.40 Sposobnost vžiga in Ignitability and burning
obnašanje materialov in behaviour of materials and
proizvodov pri gorenju products
13.230 Varstvo pred eksplozijo Explosion protection
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 15188
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2020
EUROPÄISCHE NORM
ICS 13.230 Supersedes EN 15188:2007
English Version
Determination of the spontaneous ignition behaviour of
dust accumulations
Détermination de l'aptitude à l'auto-inflammation des Bestimmung des Selbstentzündungsverhaltens von
accumulations de poussières Staubschüttungen
This European Standard was approved by CEN on 18 October 2020.
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, 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
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 15188:2020 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Test apparatus . 6
4.1 Sample baskets . 6
4.2 Determination of Basket Volume . 7
4.3 Oven and test conditions . 7
4.4 Thermocouples . 9
4.5 Temperature recording equipment . 9
5 Preparation of dust samples . 9
6 Procedure . 10
6.1 Experimental Procedure . 10
6.2 Evaluation of tests . 11
6.3 Calibration of thermocouples . 12
7 Test report . 12
8 Precision . 13
8.1 General. 13
8.2 Uncertainty of extrapolation to larger volumes . 13
8.3 Uncertainty of single-basket-test (10 cm basket) . 14
Annex A (normative) Theoretical Basis to Determinations and Extrapolations . 15
Annex B (informative) Extrapolation of induction times . 21
Annex C (informative) Extrapolation to Temperatures or Volumes of Interest by Numerical
solution of Fourier’s equation . 23
Annex D (informative) Alternative method for running tests adiabatically and interpreting
the results . 26
Annex E (normative) Safety Precautions . 30
Annex F (informative) Significant Changes between this European Standard and
EN 15188:2007 . 31
Annex ZA Annex ZA (informative) Relationship between this European Standard and the
Essential Requirements of EU Directive 2014/34/EU . 33
Bibliography . 34
European foreword
This document (EN 15188:2020) has been prepared by Technical Committee CEN/TC 305 “Potentially
explosive atmospheres – Explosion prevention and protection”, the secretariat of which is held by DIN.
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 2021, and conflicting national standards shall be
withdrawn at the latest by December 2021.
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.
This document supersedes EN 15188:2007.
This document has been prepared under a standardization request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of EU
Directive 2014/34/EU.
For relationship with EU Directive 2014/34 EU, see informative Annex ZA, which is an integral part of
this document.
According to the CEN-CENELEC Internal Regulations, the national standards organisations 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, Turkey and the
United Kingdom.
Introduction
The self-ignition behaviour of dusts and granular materials and their mixtures depends on their
chemical composition as well as on related substance and bulk properties. It also depends on the size
and geometry of the body of material, and, last but not least on the ambient temperature.
The reason for self-heating (with possible self-ignition) is that the surface molecules of combustible
dust or granular materials undergo exothermic reactions with air or other oxidising atmospheres
transported into the void volume between the particles even at normal ambient temperatures. Any heat
then released will cause the temperature of the reactive system to rise, thus accelerating the reaction of
additional molecules with oxygen, etc. A heat balance involving the heat produced inside the bulk
(quantity and surface of reactive surface molecules, specific heat producing rate) and the heat loss to
the surroundings (heat conductivity and dimension of the bulk, heat transfer coefficient on the outside
surface of the bulk and the size of the latter) is decisive as to whether a steady-state temperature is
reached at a slightly higher temperature level (the heat loss terms are larger than the heat production
term), or whether temperatures in the bulk will continue to rise up to self-ignition of the material, if
heat transport away from the system is insufficient (in this case the heat production term is larger than
all heat losses).
The experimental basis in this document for describing the self-ignition behaviour of a given dust or
granular material is the determination of the self-ignition temperatures (T ) of differently sized bulk
SI
volumes by isoperibolic hot storage experiments (storage at constant oven temperatures) in
commercially available ovens. The results thus measured reflect the dependence of self-ignition
temperatures upon volume of the accumulation.
Different evaluation procedures – described in Annex A – allow interpolation and extrapolation, to
characterize the self-ignition behaviour of deposits of a different scale and of different bulk geometric
shapes. Primary method is the evaluation based on the thermal explosion theory according to Frank-
Kamenetskii (A.2) and Thomas (A.3).
Interlaboratory tests have shown, that it is necessary to provide prescribed test conditions, e.g. by
installation of a mesh wire screen into the oven, surrounding the dust samples and the thermocouples.
In this way the spread of results will be minimized. If it is possible based on suitable thermo-analytic
test procedures (adiabatic, isothermal or dynamic tests) to derive a reliable formal kinetic model, which
describes the heat production of the substance as a function of temperature, then the volume
dependency of the self-ignition temperature may be calculated according to the methods described in
Annex A.
1 Scope
This document specifies analysis and evaluation procedures for determining self-ignition temperatures
(T ) of combustible dusts or granular materials as a function of volume by hot storage experiments in
SI
ovens of constant temperature. The specified test method is applicable to any solid material for which
the thermal explosion theory according to A.2 holds (i.e. not limited to only oxidatively unstable
materials).
The specified test is applicable to any dust or granular material that reacts primarily with oxygen from
the air. For safety reasons, this test is not used with materials mixed with solid/liquid oxidant (e.g.
gunpowder, thermites, wood impregnated with liquid oxygen) or materials that could undergo violent
non-oxidative reactions (e.g. peroxides, explosives). On a case by case basis, some types of materials
undergoing non-oxidative reactions (e.g. non-violent exothermic decomposition reactions) may be
however tested provided that additional safety precautions are taken. Where any doubt exists about the
existence of hazard due to the properties of the test material (e.g. toxic or explosive), expert advice is
sought.
This document is not applicable to the ignition of dust layers or bulk solids under aerated conditions
(e.g. as in fluid bed dryer).
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 1127-1:2019, Explosive atmospheres - Explosion prevention and protection - Part 1: Basic concepts
and methodology
EN 13237:2012, 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, the following terms and definitions given in EN 13237:2012,
EN 1127-1:2019 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 https://www.iso.org/obp
3.1
self-ignition temperature
T
SI
highest temperature at which a given volume of dust just does not ignite
Note 1 to entry: Self-ignition temperature is expressed in °C.
3.2
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.