SIST EN 14034-1:2005
(Main)Determination of explosion characteristics of dust clouds - Part 1: Determination of the maximum explosion pressure pmax of dust clouds
Determination of explosion characteristics of dust clouds - Part 1: Determination of the maximum explosion pressure pmax of dust clouds
This document describes a test method for the determination of the maximum explosion pressure of dust clouds in a closed vessel under defined initial conditions of pressure and temperature.
This method is not suitable for use with recognised explosives, like gunpowder and dynamite, substances which do not require oxygen for combustion, pyrophoric substances, or substances or mixtures of substances which may under some circumstances behave in a similar manner. Where any doubt exists about the existence of hazard due to explosive properties, expert advice should be sought.
Bestimmung der Explosionskenngrößen von Staub/Luft-Gemischen - Teil 1: Bestimmung des maximalen Explosionsdruckes pmax von Staub/Luft-Gemischen
Dieses Dokument beschreibt ein Prüfverfahren für die Bestimmung des maximalen Explosionsdruckes von Staubwolken in einem geschlossenen Behälter unter definierten Anfangsbedingungen von Druck und Temperatur.
Dieses Verfahren ist nicht geeignet für Sprengstoffe wie Schießpulver und Dynamit sowie Stoffe, die ohne Sauerstoff verbrennen, pyrophore Stoffe oder Stoffe bzw. Stoffgemische, die sich unter bestimmten Umständen ähnlich verhalten. Wenn Zweifel über eventuell vorhandene Gefährdungen durch die Explosionswirkung bestehen, sollten Fachleute zu Rate gezogen werden.
Détermination des caractéristiques d'explosion des nuages de poussiere - Partie 1 : Détermination de la pression maximale d'explosion pmax des nuages de poussiere
La présente norme décrit une méthode d'essai permettant de déterminer la pression maximale d'explosion des nuages de poussiere dans un récipient fermé, dans des conditions initiales définies de pression et de température.
Cette méthode ne convient pas aux explosifs reconnus comme tels, comme la poudre et la dynamite, aux explosifs dont la combustion ne nécessite pas d'oxygene, aux substances pyrophoriques, ou aux substances ou mélanges de substances pouvant, dans certaines circonstances, se comporter de maniere similaire. Lorsqu'il existe un doute sur l'existence d'un phénomene dangereux en raison de propriétés explosives, il convient de faire appel a l'avis d'experts.
Ugotavljanje eksplozijskih značilnosti oblakov prahu - 1. del: Ugotavljanje najvišjega tlaka eksplozije pmax oblakov prahu
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 14034-1:2005
01-marec-2005
8JRWDYOMDQMHHNVSOR]LMVNLK]QDþLOQRVWLREODNRYSUDKXGHO 8JRWDYOMDQMH
QDMYLãMHJDWODNDHNVSOR]LMHSPD[REODNRYSUDKX
Determination of explosion characteristics of dust clouds - Part 1: Determination of the
maximum explosion pressure pmax of dust clouds
Bestimmung der Explosionskenngrößen von Staub/Luft-Gemischen - Teil 1: Bestimmung
des maximalen Explosionsdruckes pmax von Staub/Luft-Gemischen
Détermination des caractéristiques d'explosion des nuages de poussiere - Partie 1 :
Détermination de la pression maximale d'explosion pmax des nuages de poussiere
Ta slovenski standard je istoveten z: EN 14034-1:2004
ICS:
13.230 Varstvo pred eksplozijo Explosion protection
SIST EN 14034-1:2005 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 14034-1:2005
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SIST EN 14034-1:2005
EUROPEAN STANDARD
EN 14034-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2004
ICS 13.230
English version
Determination of explosion characteristics of dust clouds - Part
1: Determination of the maximum explosion pressure p of
max
dust clouds
Détermination des caractéristiques d'explosion des nuages Bestimmung der Explosionskenngrößen von Staub/Luft-
de poussière - Partie 1 : Détermination de la pression Gemischen - Teil 1: Bestimmung des maximalen
maximale d'explosion pmax des nuages de poussière Explosionsdruckes pmax von Staub/Luft-Gemischen
This European Standard was approved by CEN on 9 July 2004.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14034-1:2004: E
worldwide for CEN national Members.
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SIST EN 14034-1:2005
EN 14034-1:2004 (E)
Contents page
Foreword.4
1 Scope .6
2 Normative references .6
3 Terms and definitions .6
4 Test apparatus .7
4.1 General.7
4.2 Explosion vessel.7
4.3 Dust dispersion system (dust container, fast acting valve, connecting tube, dust
disperser).9
4.4 Ignition source .11
4.5 Control unit.11
4.6 Pressure measuring system.11
5 Dust sample.11
6 Test procedure.12
7 Calibration and verification .14
7.1 Calibration .14
7.2 Verification .15
8 Safety precautions / instructions for use.15
9 Alternative test equipment / procedures.16
10 Test report .16
Annex A (normative) Electro pneumatic valve .17
Annex B (normative) Dust disperser with 5 mm holes .19
Annex C (normative) 20 l sphere.23
C.1 General.23
C.2 Test apparatus .23
C.3 Test conditions .23
C.4 Test procedure.24
C.5 Calculation and correction of p .25
max
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 94/9 .26
Bibliography .27
Foreword.4
Introduction .5
1 Scope .6
2 Normative references .6
3 Terms and definitions .6
4 Test apparatus .7
4.1 General.7
4.2 Explosion vessel.7
2
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SIST EN 14034-1:2005
EN 14034-1:2004 (E)
4.3 Dust dispersion system (dust container, fast acting valve, connecting tube, dust
disperser) .9
4.4 Ignition source.11
4.5 Control unit .11
4.6 Pressure measuring system.11
5 Dust sample .11
6 Test procedure.12
7 Calibration and verification .14
7.1 Calibration.14
7.2 Verification .15
8 Safety precautions / instructions for use.15
9 Alternative test equipment / procedures.16
10 Test report.16
Annex A (normative) Electro pneumatic valve.17
Annex B (normative) Dust disperser with 5 mm holes.19
Annex C (normative) 20 l sphere.23
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 94/9.26
Bibliography.27
3
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SIST EN 14034-1:2005
EN 14034-1:2004 (E)
Foreword
This document (EN 14034-1:2004) 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 March 2005, and conflicting national standards shall be withdrawn at
the latest by March 2005.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative annex ZA, which is an integral part of this document.
This document includes a Bibliography.
This document is one of a series of standards as listed below:
EN 14034-1,Determination of explosion characteristics of dust clouds - Part 1: Determination of the
maximum explosion pressure p of dust clouds;
max
prEN 14034-2, Determination of explosion characteristics of dust clouds - Part 2: Determination of the
maximum rate of explosion pressure rise (dp/dt) of dust clouds;
max
prEN 14034-3, Determination of explosion characteristics of dust clouds – Part 3: Determination of the
lower explosion limit LEL of dust clouds;
EN 14034-4, Determination of explosion characteristics of dust clouds – Part 4: Determination of the
limiting oxygen concentration LOC of dust clouds.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland
and United Kingdom.
4
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SIST EN 14034-1:2005
EN 14034-1:2004 (E)
Introduction
This document specifies a method for experimental determination of the maximum explosion pressure of dust
clouds. The maximum explosion pressure is the maximum value of the overpressure during explosions of
explosive atmospheres in the explosion range of a combustible dust in a closed vessel. The measurement of
the maximum explosion pressure forms the basis for explosion protection by design and construction of
equipment, protective systems and components to reduce the explosion effects.
This maximum explosion pressure is a safety characteristic used for hazard identification and designing safety
measures for the mitigation of destructive effects of dust explosions.
Therefore this document gives added values to the following clauses of the EU directives:
Directive 98/37/EC of the European Parliament and the Council of June 22, 1998 on the approximation of
the laws of the member states relating to machinery
Annex I, Clause 1.5.7
Directive 94/9/EC of the European Parliament and the Council of March 23, 1994 on the approximation of
the laws of the member states concerning equipment and protective systems intended for use in
potentially explosive atmospheres.
Annex II, Clause 1.0.1
5
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SIST EN 14034-1:2005
EN 14034-1:2004 (E)
1 Scope
This document describes a test method for the determination of the maximum explosion pressure of dust
clouds in a closed vessel under defined initial conditions of pressure and temperature.
This method is not suitable for use with recognised explosives, like gunpowder and dynamite, substances
which do not require oxygen for combustion, pyrophoric substances, or substances or mixtures of substances
which may under some circumstances behave in a similar manner. Where any doubt exists about the
existence of hazard due to explosive properties, expert advice should be sought.
2 Normative references
The following referenced documents are indispensable for the application 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.
prEN 14460, Explosion resistant equipment.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
dust
small solid particles in the atmosphere which settle out under their own weight, but which may remain
suspended in air for some time (includes dust and grit, as defined in ISO 4225)
NOTE Generally maximum particle size will not exceed 500 µm.
3.2
combustible dust
dust able to undergo an exothermic reaction with air when ignited
NOTE The terms “flammable” and “combustible” are used synonymously.
3.3
explosion pressure
p
ex
the highest overpressure occurring during an explosion of a dust cloud in a closed vessel
3.4
explosive atmosphere
mixture with air, under atmospheric conditions, of flammable (combustible) substances in the form of gases,
vapours, mists or dusts, in which, after ignition has occurred, combustion spreads to the entire unburned
mixture
3.5
ignition delay
t
v
time between the initiation of the dust dispersion and the activation of the ignition source
3.6
initial pressure
p
i
the pressure in the explosion vessel at the moment of ignition
6
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SIST EN 14034-1:2005
EN 14034-1:2004 (E)
3.7
initial temperature
T
i
the temperature in the explosion vessel at the moment of ignition
3.8
maximum explosion pressure
p
max
maximum overpressure occurring in a closed vessel during the explosion of an explosive atmosphere
determined under specified test conditions and standard atmospheric conditions. (Maximum value of the
explosion pressure p determined by tests covering the explosible range of dust concentrations).
ex
4 Test apparatus
4.1 General
The standard test apparatus to determine the maximum explosion pressure p of dust clouds is an explosion
max
pressure resistant vessel of 1 m³, as used for the determination of the maximum rate of explosion pressure
rise (K -value) and the lower explosion limit of dust clouds as well as the limiting oxygen concentration of
St
dust/air/inert gas mixtures.
The main components of the test apparatus are
explosion vessel;
dust dispersion system;
ignition source;
control unit;
pressure measuring system.
NOTE The 20 l sphere apparatus is an alternative explosion vessel for these determinations (see annex C)
4.2 Explosion vessel
The standard explosion vessel is an explosion pressure resistant, spherical or cylindrical vessel in accordance
with prEN 14460 having a volume of 1 m³. The aspect ratio of the cylindrical vessel shall be 1:1 ± 10 % (see
Figure 1).
NOTE It is recommended that the explosion vessel be designed to withstand an overpressure of at least 20 bar.
The apparatus shall be fitted with electrical and/or mechanical cut-offs as far as possible to ensure that any
openings in the vessel (e.g. main door, instrument ports, inlet or outlet) are properly closed before a test
procedure can start.
The apparatus shall also be equipped as far as possible to ensure that any residual pressure inside the vessel
is vented before the vessel can be opened.
7
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SIST EN 14034-1:2005
EN 14034-1:2004 (E)
Key
1 Pressure sensor 5 Dust container
2 Chemical igniters 6 Fast acting valve
3 Inlet for purge air 7 Connecting tube
4 Dust disperser 8 Outlet for exhaust gas
Figure 1 — 1 m³ vessel (schematic)
8
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SIST EN 14034-1:2005
EN 14034-1:2004 (E)
4.3 Dust dispersion system (dust container, fast acting valve, connecting tube, dust
disperser)
The dust to be dispersed is charged into a dust container having a volume of 5,4 dm³. Its aspect ratio is 3:1. It
is designed to withstand an internal overpressure of at least 20 bar (see Figure 2).
The dust container has an outlet at the base, through which the dust leaves the container. This outlet is closed
by a fast acting valve activated by a blasting cap. The valve has a mushroom-shaped seal. The seal is held in
position against the pressure in the dust container by a small ring. The ring is destroyed by firing a blasting
cap and the valve opens due to the pressure inside the dust container (see Figure 2). The valve shall be
designed so that it opens in less than 10 ms. For alternative valves see annex A.
The fast acting valve is connected to the side of the explosion vessel. The connecting tube between the fast
acting valve and the dust disperser shall be not longer than 350 mm (see Figure 1).
Key
1 Dust container 5 Protective hood
2 Mushroom shaped seal 6 Protective hood
3 Seal housing 7 Blasting cap
4 Support ring 8 Connecting tube
Figure 2 — Dust container with blasting cap activated valve as commonly used for explosion
suppression (schematic; it is commercially available)
For dispersing the dust, a perforated semicircular spray pipe (dust disperser) is mounted inside the explosion
)
1
vessel, concentric with its wall. The spray pipe, with an internal diameter of 21,7 mm is fitted with 13 holes of
a diameter of 6 mm (incl. one hole in each end cap) which shall be located as shown in Figure 3 (see also
Figure 1).
1
(e. g. EN ISO 1127, DN 20, ¾")
9
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SIST EN 14034-1:2005
EN 14034-1:2004 (E)
For coarse, vol
...
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