SIST EN 14034-1:2005+A1:2011
(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 legt ein Prüfverfahren für die Bestimmung des maximalen Explosionsdruckes von Staubwolken in einem geschlossenen Behälter unter definierten Anfangsbedingungen von Druck und Temperatur fest. 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 Explosions-wirkung bestehen, sollten Fachleute zu Rate gezogen werden.
Détermination des caractéristiques d'explosion des nuages de poussière - Partie 1: Détermination de la pression maximale d'explosion pmax des nuages de poussière
La présente norme décrit une méthode d'essai permettant de déterminer la pression maximale d'explosion des
nuages de poussière 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'oxygène, aux substances pyrophoriques ou aux substances ou mélanges
de substances pouvant, dans certaines circonstances, se comporter de manière similaire. Lorsqu'il existe un
doute sur l'existence d'un phénomène dangereux en raison de propriétés explosives, il convient de faire appel
à l'avis d'experts.
Ugotavljanje eksplozijskih značilnosti oblakov prahu - 1. del: Ugotavljanje najvišjega tlaka eksplozije pmax oblakov prahu
Ta dokument opisuje preskusno metodo za ugotavljanje najvišjega tlaka eksplozije oblakov prahu v zaprti posodi pod opredeljenimi začetnimi pogoji glede tlaka in temperature.
Ta metoda ni primerna za uporabo s priznanimi eksplozivi, kot so smodnik in dinamit, snovi, ki za izgorevanje ne potrebujejo kisika, piroforne snovi ali snovi ali zmesi snovi, ki se lahko v nekaterih okoliščinah podobno obnašajo. Kadar obstaja kakršen koli dvom o nevarnosti zaradi eksplozivnih lastnosti, je treba poiskati strokovni nasvet.
General Information
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Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.RWDYOMDQMHBestimmung der Explosionskenngrößen von Staub/Luft-Gemischen - Teil 1: Bestimmung des maximalen Explosionsdruckes pmax von Staub/Luft-GemischenDétermination des caractéristiques d'explosion des nuages de poussière - Partie 1: Détermination de la pression maximale d'explosion pmax des nuages de poussièreDetermination of explosion characteristics of dust clouds - Part 1: Determination of the maximum explosion pressure pmax of dust clouds13.230Varstvo pred eksplozijoExplosion protectionICS:Ta slovenski standard je istoveten z:EN 14034-1:2004+A1:2011SIST EN 14034-1:2005+A1:2011en,fr,de01-maj-2011SIST EN 14034-1:2005+A1:2011SLOVENSKI
STANDARD
SIST EN 14034-1:2005+A1:2011
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14034-1:2004+A1
January 2011 ICS 13.230 Supersedes EN 14034-1:2004English Version
Determination of explosion characteristics of dust clouds - Part 1: Determination of the maximum explosion pressure pmax of dust clouds
Détermination des caractéristiques d'explosion des nuages de poussière - Partie 1: Détermination de la pression maximale d'explosion pmax des nuages de poussière
Bestimmung der Explosionskenngrößen von Staub/Luft-Gemischen - Teil 1: Bestimmung des maximalen Explosionsdruckes pmax von Staub/Luft-Gemischen This European Standard was approved by CEN on 9 July 2004 and includes Amendment 1 approved by CEN on 13 November 2010.
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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14034-1:2004+A1:2011: ESIST EN 14034-1:2005+A1:2011
EN 14034-1:2004+A1:2011 (E) 2 Contents page Foreword .31Scope .52Normative references .53Terms and definitions .54Test apparatus .64.1General .64.2Explosion vessel .64.3Dust dispersion system (dust container, fast acting valve, connecting tube, dust disperser) .84.4Ignition source . 114.5Control unit . 114.6Pressure measuring system . 115Dust sample . 116Test procedure . 127Calibration and verification . 147.1Calibration . 147.2Verification . 158Safety precautions / instructions for use . 159Alternative test equipment / procedures . 1610Test report . 16Annex A (normative)
Electro pneumatic valve . 17Annex B (normative)
Dust disperser with 5 mm holes . 19Annex C (normative)
20 l sphere . 23C.1General . 23C.2Test apparatus . 23C.3Test conditions . 23C.4Test procedure . 24C.5Calculation and correction of pmax . 25Annex ZA (informative)
!!!!Relationship between this European Standard and the Essential Requirements of EU Directive 94/9/EC"""" . 26Bibliography . 27
SIST EN 14034-1:2005+A1:2011
EN 14034-1:2004+A1:2011 (E) 3 Foreword This document (EN 14034-1:2004+A1:2011) 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 July 2011, and conflicting national standards shall be withdrawn at the latest by July 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document includes Amendment 1, approved by CEN on 2010-11-13. This document supersedes EN 14034-1:2004. The start and finish of text introduced or altered by amendment is indicated in the text by tags
!". 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 pmax of dust clouds; !EN 14034-2", Determination of explosion characteristics of dust clouds - Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds; !EN 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, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. SIST EN 14034-1:2005+A1:2011
EN 14034-1:2004+A1:2011 (E) 4 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.
!deleted text" SIST EN 14034-1:2005+A1:2011
EN 14034-1:2004+A1:2011 (E) 5 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.
!EN 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 pex 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 tv time between the initiation of the dust dispersion and the activation of the ignition source 3.6 initial pressure pi the pressure in the explosion vessel at the moment of ignition SIST EN 14034-1:2005+A1:2011
EN 14034-1:2004+A1:2011 (E) 6 3.7 initial temperature Ti the temperature in the explosion vessel at the moment of ignition 3.8 maximum explosion pressure pmax 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 pex determined by tests covering the explosible range of dust concentrations). 4 Test apparatus 4.1 General The standard test apparatus to determine the maximum explosion pressure pmax of dust clouds is an explosion pressure resistant vessel of 1 m³, as used for the determination of the maximum rate of explosion pressure rise (KSt-value) and the lower explosion limit of dust clouds as well as the limiting oxygen concentration of 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 !EN 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. SIST EN 14034-1:2005+A1:2011
EN 14034-1:2004+A1:2011 (E) 7
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) SIST EN 14034-1:2005+A1:2011
EN 14034-1:2004+A1:2011 (E) 8
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). SIST EN 14034-1:2005+A1:2011
EN 14034-1:2004+A1:2011 (E) 9
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) SIST EN 14034-1:2005+A1:2011
EN 14034-1:2004+A1:2011 (E) 10 For dispersing the dust, a perforated semicircular spray pipe (dust disperser) is mounted inside the explosion vessel, concentric with its wall. The spray pipe, with an internal diameter of 21,7 mm 1) 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). For coarse, voluminous, fibrous or poorly flowing dust samples, it may not be possible to properly discharge the dust through the dust dispersers detailed in Figures 3 and B.1. It may, therefore, be necessary to use special dust dispersers, examples of which are given in Figures B.2 and B.3. In such cases, the dust disperser used shall be described in the test report. NOTE If other dust dispersing systems than those described in this standard are used, a propagation of the explosion from the explosion vessel into the dust container, cannot be excluded. For this case, additional safety measures should be employed, e.g. higher pressure resistance of the dust container. Dimensions in millimetres
Key 1 6 mm hole 2 End cap with 6 mm hole Figure 3 — Location of the 6 mm holes in the dust disperser
1
(e. g. EN ISO 1127, DN 20, ¾") SIST EN 14034-1:2005+A1:2011
EN 14034-1:2004+A1:2011 (E) 11 4.4 Ignition source !The ignition source comprises two electrically activated pyrotechnical igniters, each having an ignition energy of 5 kJ. This is the nominal calorimetric energy based on the mass of pyrotechnic powder in the igniters. When activated, the igniters shall release a dense cloud of very hot particles with little gas. The igniters are fired by electrical fuse heads. The power supply circuit for the igniters shall be capable of firing the fuse heads in less than 10 ms. The two igniters shall be placed at the centre of the explosion vessel, firing in opposite directions (see Figure 1)." 4.5 Control unit The control unit sequences the start of the dust injection, the activation of the ignition source and the start of the recording system. 4.6 Pressure measuring system The pressure measuring system includes at least two pressure sensors and recording equipment. The pressure sensors shall be fitted in the test vessel, with their heads flush with the internal wall. Pre
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