EN 14034-1-2004 en Determination of explosion characteristics of dust clouds - Part 1 Determination of the maximum explosion pressure Pmax of dust clouds (Incorporates Amendment A1.pdf

1、BRITISH STANDARDBS EN 14034-1:2004Determination of explosioncharacteristics of dust clouds Part 1: Determination of the maximum explosion pressure maxof dust cloudsICS 13.230g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g

2、51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58+A1:2011BS EN 14034-1:2004+A1:2011This British Standard was published under the authority of the Standards Policy and Strategy Committee on 24 June 2005 BSI 2011ISBN 978 0 580 73580 6National forewordThis British Standard is t

3、he UK implementation of EN 14034-1:2004+A1:2011.The UK participation in its preparation was entrusted to Technical Committee FSH/23, Fire precautions in industrial and chemical plant.A list of organizations represented on this committee can be obtained on request to its secretary.This publication do

4、es not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.It supersedes BS EN 14034-1:2004 which is withdrawn.The start and finish of text introduced or alte

5、red by amendment is indicated in the text by tags. Tags indicating changes to CEN text carry the number of the CEN amendment. For example, text altered by CENamendment A1 is indicated by !“.Amendments/corrigenda issued since publicationDate Comments 31 July 2010 Implementation of CEN amendment A1:20

6、11EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE 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 pmaxof dust clouds Dtermination des caractristi

7、ques dexplosion des nuages de poussire - Partie 1: Dtermination de la pression maximale dexplosion pmaxdes nuages de poussire Bestimmung der Explosionskenngren von Staub/Luft-Gemischen - Teil 1: Bestimmung des maximalen Explosionsdruckes pmaxvon Staub/Luft-Gemischen This European Standard was approv

8、ed 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

9、 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 t

10、he 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, Ger

11、many, 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 COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUN

12、G 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: E2 Contents page Foreword 31 Scope 52 Normative references 53 Terms and definitions .54 Test apparatu

13、s .64.1 General 64.2 Explosion vessel 64.3 Dust dispersion system (dust container, fast acting valve, connecting tube, dust disperser) 84.4 Ignition source 114.5 Control unit 114.6 Pressure measuring system 115 Dust sample . 116 Test procedure 127 Calibration and verification . 147.1 Calibration . 1

14、47.2 Verification 158 Safety precautions / instructions for use . 159 Alternative test equipment / procedures 1610 Test report . 16Annex A (normative) Electro pneumatic valve 17Annex B (normative) Dust disperser with 5 mm holes 19Annex C (normative) 20 l sphere . 23C.1 General . 23C.2 Test apparatus

15、 23C.3 Test conditions . 23C.4 Test procedure 24C.5 Calculation and correction of pmax25Annex ZA (informative) !Relationship between this European Standard and the Essential Requirements of EU Directive 94/9/EC“ 26Bibliography . 27BS EN 14034-1:2004+A1:2011EN 14034-1:2004+A1:2011 (E)3 Foreword This

16、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

17、 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 he

18、ld 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 prepa

19、red 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 Bibliogra

20、phy. 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 pmaxof dust clouds; !EN 14034-2“, Determination of explosion characteristics of dust clouds - Part 2: Det

21、ermination of the maximum rate of explosion pressure rise (dp/dt)maxof 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 Par

22、t 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, D

23、enmark, 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. BS EN 14034-1:2004+A1:2011EN 14034-1:2004+A1:2011 (E)4 Introdu

24、ction 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.

25、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 designi

26、ng safety measures for the mitigation of destructive effects of dust explosions. !deleted text“ BS EN 14034-1:2004+A1:2011EN 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

27、 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 behav

28、e 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 appl

29、ies. 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 atmosp

30、here 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 m. 3.2 combustible dust dust able to undergo an exothermic reaction with air when ignited NOTE T

31、he 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 for

32、m 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 vesse

33、l at the moment of ignition BS EN 14034-1:2004+A1:2011EN 14034-1:2004+A1:2011 (E)6 3.7 initial temperature Tithe 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 at

34、mosphere determined under specified test conditions and standard atmospheric conditions. (Maximum value of the explosion pressure pexdetermined by tests covering the explosible range of dust concentrations). 4 Test apparatus 4.1 General The standard test apparatus to determine the maximum explosion

35、pressure pmaxof dust clouds is an explosion pressure resistant vessel of 1 m, 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 co

36、mponents 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 exp

37、losion pressure resistant, spherical or cylindrical vessel in accordance with !EN 14460“ having a volume of 1 m. 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.

38、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

39、ensure that any residual pressure inside the vessel is vented before the vessel can be opened. BS EN 14034-1:2004+A1:2011EN 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 e

40、xhaust gas Figure 1 1 m vessel (schematic) BS EN 14034-1:2004+A1:2011EN 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 dm. Its aspect ratio is 3

41、: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 s

42、eal 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

43、 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). BS EN 14034-1:2004+A1:2011EN 14034-1:2004+A1:2011 (E)9 Key 1 Dust container 5 Protective hood

44、 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) BS EN 14034-1:2004+A1:2011EN 14034-1:2004+A1:2011 (E

45、)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 mm1) is fitted with 13 holes of a diameter of 6 mm (incl. one hole in each end cap) which shall be lo

46、cated 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

47、 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 exc

48、luded. 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, “) BS EN 14034-1:2004+A

49、1:2011EN 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