SIST EN 14034-2:2006+A1:2011

Determination of explosion characteristics of dust clouds - Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds

This standard describes a test method for the determination of the maximum rate of explosion pressure rise 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, explosives 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 2: Bestimmung des maximalen zeitlichen Druckanstiegs (dp/dt)max von Staub/Luft-Gemischen

Diese Norm legt ein Prüfverfahren für die Bestimmung des maximalen zeitlichen Druckanstiegs 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 2: Détermination de la vitesse maximale de montée en pression d'explosion (dp/dt)max des nuages de poussière

La présente Norme spécifie une méthode d’essai pour déterminer la vitesse maximale de montée en pression lors
de l’explosion de nuages de poussière dans un récipient fermé, dans des conditions initiales de pression et de
températures définies.
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 et 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 - 2. del: Ugotavljanje največje hitrosti naraščanja tlaka eksplozije (dp/dt)max oblakov prahu

Ta standard opisuje preskusno metodo za ugotavljanje največje hitrosti naraščanja 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, eksplozivi, ki za izgorevanje ne potrebujejo kisika, piroforne snovi ali snovi ali zmesi snovi, ki se lahko pod nekaterimi okoliščinami podobno obnašajo. Kadar obstaja kakršen koli dvom o nevarnosti zaradi eksplozivnih lastnosti, je treba poiskati strokovni nasvet.

General Information

• Status: Published
• Publication Date: 06-Apr-2011
• ICS: 13.230 - Explosion protection
• Technical Committee: EXP - Product for explosive atmospheres
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 24-Mar-2011
• Due Date: 29-May-2011
• Completion Date: 07-Apr-2011
• Directive: 2014/34/EU - Directive 2014/34/EU Of The European Parliament And Of The Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres (recast)
• Directive: 94/9/EC - Directive 94/9/EC of the European Parliament and the Council of 23 March 1994 on the approximation of the laws of the Member States concerning equipment and protective systems intended for use in potentially explosive atmospheres
• Mandate: M/396 - Mandate to CEN and Cenelec for standardisation in the field of machinery
• Ref Project: EN 14034-2:2006+A1:2011 - Determination of explosion characteristics of dust clouds - Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds

Relations

• Consolidates: SIST EN 14034-2:2006 - Determination of explosion characteristics of dust clouds - Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds
• Effective Date: 01-May-2011

Overview

EN 14034-2:2006+A1:2011 is a CEN standard that specifies a laboratory test method to determine the maximum rate of explosion pressure rise ((dp/dt)max) for combustible dust clouds. The method measures the steepest slope of the pressure–time curve during a dust explosion in a closed vessel under defined initial pressure and temperature. Results support explosion protection design, equipment selection and risk assessment for dust-handling processes. The standard is part of the EN 14034 series and aligns with EU requirements (see Annex ZA and Directive 94/9/EC).

Key topics and technical requirements

• Test apparatus: Standard apparatus is a 1 m³ explosion-resistant vessel (spherical or cylindrical, aspect ratio ~1:1). A 20 l sphere is permitted as an alternative (Annex C).
• Main components: explosion vessel, dust dispersion system (5.4 dm³ dust container with fast-acting valve), dust disperser (perforated spray pipe), ignition source (two pyrotechnic igniters, 5 kJ each), control unit and pressure-measuring system.
• Dust dispersion details: dust container connects to the vessel via a short tube (≤350 mm); valve must open rapidly (≤10 ms). Standard dust disperser uses a 21.7 mm pipe with 13 holes (6 mm diameter) positioned concentrically.
• Measured parameters: (dp/dt)max (bar·s⁻¹) and derived, volume-independent characteristics Kmax / KSt (related by the cubic law). The document clarifies units and equivalence when measured in the 1 m³ vessel.
• Safety and exclusions: not applicable to recognized high explosives (gunpowder, dynamite), substances that combust without oxygen, pyrophoric materials or mixtures that may behave similarly. Calibration, verification, and safety procedures are mandatory.
• Performance & design: recommended vessel strength (e.g., withstand ≥20 bar overpressure), instrumentation and procedural controls to prevent accidental release or opening under pressure.

Applications and who uses it

• Industrial safety engineers and plant designers evaluating explosion hazards in food processing, pharmaceuticals, chemical, wood, metal dust and bulk-material industries.
• Test laboratories performing dust explosion testing and certification.
• Manufacturers of process equipment, explosion suppression systems and protective devices who require validated (dp/dt)max and KSt data for design.
• Risk assessors and compliance teams preparing documentation for ATEX/Directive 94/9/EC and machine safety.

Related standards

• EN 14034-1 - Determination of maximum explosion pressure (pmax)
• EN 14034-3 - Determination of lower explosion limit (LEL)
• EN 14034-4 - Determination of limiting oxygen concentration (LOC)
• EN 14460 - Explosion resistant equipment

Keywords: EN 14034-2, dp/dt max, dust explosion testing, KSt, explosion pressure rise, 1 m3 vessel, dust disperser, explosion protection.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Bestimmung der Explosionskenngrößen von Staub/Luft-Gemischen - Teil 2: Bestimmung des maximalen zeitlichen Druckanstiegs (dp/dt)max von Staub/Luft-GemischenDétermination des caractéristiques d'explosion des nuages de poussière - Partie 2: Détermination de la vitesse maximale de montée en pression d'explosion (dp/dt)max des nuages de poussièreDetermination of explosion characteristics of dust clouds - Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds13.230Varstvo pred eksplozijoExplosion protectionICS:Ta slovenski standard je istoveten z:EN 14034-2:2006+A1:2011SIST EN 14034-2:2006+A1:2011en,fr,de01-maj-2011SIST EN 14034-2:2006+A1:2011SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14034-2:2006+A1
January 2011 ICS 13.230 Supersedes EN 14034-2:2006English Version
Determination of explosion characteristics of dust clouds - Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds
Détermination des caractéristiques d'explosion des nuages de poussière - Partie 2: Détermination de la vitesse maximale de montée en pression d'explosion (dp/dt)max des nuages de poussière
Bestimmung der Explosionskenngrößen von Staub/Luft-Gemischen - Teil 2: Bestimmung des maximalen zeitlichen Druckanstiegs (dp/dt)max von Staub/Luft-Gemischen This European Standard was approved by CEN on 20 April 2006 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 14034-2:2006+A1:2011: ESIST EN 14034-2:2006+A1:2011

Electro Pneumatic Valve . 19Annex B (normative)
Dust dispenser with 5 mm holes . 22Annex C (normative)
20 l sphere . 25C.1 General . 25C.2 Test apparatus . 25C.3 Test conditions . 26C.4 Test procedure . 26C.5 Calculation of (dp/dt)max, 20 l, Kmax and KSt . 27Annex ZA (informative)
!!!!Relationship between this European Standard and the Essential Requirements of EU Directive 94/9/EC"""" . 28Bibliography . 29Figures Figure 1 — 1 m³ vessel (schematic) . 9Figure 2 — Dust container with blasting cap activated valve as commonly used for explosion suppression (schematic; it is commercially available) . 10Figure 3 — Location of the 6 mm holes in the dust disperser . 12Figure 4 — Dust dispersion and pressure-time curve . 15Figure 5 — Determination of the maximum rate of explosion pressure rise (dp/dt)max. 16Figure A.1 — Electro Pneumatic Valve (schematic) . 20SIST EN 14034-2:2006+A1:2011

!". 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 Directives. For relationship with the EU Directive 94/9/EC, see informative Annex ZA, which is an integral part of this document. This European Standard is one of a series of standards as listed below: EN 14034 "Determination of explosion characteristics of dust clouds" – Part 1: Determination of the maximum explosion pressure pmax of dust clouds; – Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds; – Part 3: Determination of the lower explosion limit LEL 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.
1 Scope This standard describes a test method for the determination of the maximum rate of explosion pressure rise 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, explosives 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 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 SIST EN 14034-2:2006+A1:2011

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 14034-2:2006+A1:2011

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 vessel, concentric with its wall. The spray pipe, with an internal diameter of 21,7 mm1) is fitted with 13 holes of a diameter of 6 mm (incl. one hole in each end cap) which are 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
1) (e.g. EN ISO 1127, DN 20, 3/4") SIST EN 14034-2:2006+A1:2011

Key 1 6 mm hole 2 end cap with 6 mm hole Figure 3 — Location of the 6 mm holes in the dust disperser SIST EN 14034-2:2006+A1:2011
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