EN 17077-2018 en Determination of burning behaviour of dust layers.pdf

1、BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06Determination of burning behaviour of dust layersBS EN 17077:2018EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 17077 May 2018 ICS 13.220.40 English Version Determination of burning behaviour of dust layers Dtermi

2、nation du comportement lors de la combustion des couches de poussires Bestimmung des Brandverhaltens von StaubschichtenThis European Standard was approved by CEN on 9 March 2018. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

3、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 ver

4、sions (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

5、, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain,

6、Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels 2018 CEN All rights of exploitation in any form and by any means reserved worldwid

7、e for CEN national Members. Ref. No. EN 17077:2018 ENational forewordThis British Standard is the UK implementation of EN 17077:2018. The UK participation in its preparation was entrusted to Technical Committee EXL/23, Explosion and fire precautions in industrial and chemical plant.A list of organiz

8、ations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2018 Published by BSI Standards Limited 2018I

9、SBN 978 0 580 92306 7ICS 13.220.40Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 May 2018.Amendments/corrigenda issued since publicationDate Text affectedBR

10、ITISH STANDARDBS EN 17077:2018EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 17077 May 2018 ICS 13.220.40 English Version Determination of burning behaviour of dust layers Dtermination du comportement lors de la combustion des couches de poussires Bestimmung des Brandverhaltens von Staubschich

11、tenThis European Standard was approved by CEN on 9 March 2018. 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 ref

12、erences 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 C

13、EN 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, Former Yugoslav Republic of Macedon

14、ia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATIO

15、N EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels 2018 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 17077:2018 EBS EN 17077:2018EN 17077:2018 (E) 2 Contents Page European forew

16、ord . 3 Introduction 4 1 Scope 5 2 Normative references 5 3 Terms and definitions . 5 4 Principle of the test method 6 5 Test equipment 6 5.1 General 6 5.2 Test apparatus 6 5.2.1 Board method . 6 5.2.2 Ltolf apparatus 7 5.3 Ignition source . 8 6 Characterization of dust sample 8 7 Test procedure . 9

17、 7.1 General 9 7.2 Sample preparation 9 7.2.1 Board method . 9 7.2.2 Ltolf apparatus method 9 7.3 Ignition procedure 9 7.4 Evaluation 9 7.5 Additional tests for melting substances . 11 8 Safety precautions / instructions . 11 9 Test report 12 Annex A (informative) Tests at elevated initial temperatu

18、res . 14 A.1 Additional equipment. 14 A.2 Additional information in the test-report . 14 Annex B (informative) Alternative test apparatus 15 B.1 Principles 15 B.2 Evaluation of results . 16 Annex C (informative) Example materials demonstrating behaviour typical of each of the burning classes . 17 An

19、nex ZA (informative) Relationship between this European Standard and the essential requirements of Directive 2014/34/EU aimed to be covered . 18 Bibliography . 19 BS EN 17077:2018EN 17077:2018 (E) 3 European foreword This document (EN 17077:2018) has been prepared by Technical Committee CEN/TC 305 “

20、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 November 2018, and conflicting nati

21、onal standards shall be withdrawn at the latest by November 2018. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN not be held responsible for identifying any or all such patent rights. This document has been prepared under a m

22、andate 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, see informative Annex ZA, which is an integral part of this document. According to the CEN/CENELEC Internal Regu

23、lations, 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, I

24、taly, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 17077:2018EN 17077:2018 (E) 4 Introduction This document specifies a method for experimental determination of the b

25、urning behaviour of dust layers. The determination of burning behaviour of a dust layer is a screening test required to assess the type and magnitude of the fire risk associated with the dust. The determination of the burning behaviour enables assessment of whether a material layer, when in contact

26、with an external ignition source shows a reaction (e.g. ignition, smouldering). It also measures the ability of the locally induced reaction to propagate through the material in bulk or layer form. The behaviour in the test is characterized as a class number (burning class). The burning class allows

27、 qualitative estimations on the burning behaviour of a dust layer as well as on the probability of transfer of glowing particles and glowing nests from upstream connected parts of a plant. It is therefore in certain cases a basis for explosion prevention and protection measures. In addition to that

28、the burning class is used as basis to decide whether fire prevention and protection measures are necessary. Therefore this document gives added values to the following clauses of the EU directives: Directive 2014/34/EU of the European Parliament and the Council of 26 February 2014 on the harmonisati

29、on of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres. The burning behaviour can be markedly affected by physical characteristics (e.g. particle size, packing density) and external factors (e.g. temperature, air movemen

30、t across the surface of the dust). To obtain comparable and reliable results, it is necessary to standardize the conditions under which the burning behaviour is measured. Further testing may be required for those substances which melt or for which rapid propagation of the combustion reaction is obse

31、rved in the initial test. If additional information is requested for labelling of the substances according to Regulation (EC) No 1272/2008 (i.e. whether labelling as H228: flammable solid is appropriate) and if testing according to this standard leads to a determination of burning class 4 or 5, then

32、 further testing according to the UN (United Nations) Manual of Tests and criteria test N.1 3 is required. BS EN 17077:2018EN 17077:2018 (E) 5 1 Scope This European Standard describes a test method for the determination of the burning behaviour of dust layers under defined initial conditions of air

33、flow, temperature and ignition. A test result of “burning class 1” with the described method does not mean that a dust cannot be ignited when dispersed in a cloud. This method is not suitable for use with recognized explosives, like gunpowder and dynamite, explosives which do not require atmospheric

34、 oxygen for combustion, pyrophoric substances, or substances or mixtures of substances which may under some circumstances behave in a similar manner. Expert advice should be called in, when any doubt exists about the existence of hazard due to explosive properties. 2 Normative references The followi

35、ng 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-

36、1:2011, 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 p

37、urposes of this document, the terms and definitions given in EN 13237, EN 1127-1 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: avai

38、lable at http:/www.iso.org/obp 3.1 air flow velocity volume of air m3 which flows through a defined surface m2 per unit time s 3.2 combustion exothermic reaction with either flames, glowing or smouldering when ignited Note to entry: For the purpose of this standard “combustion” includes decompositio

39、n 3.3 ignition initiation of combustion 3.4 initial temperature temperature of the dust train at the moment of ignition BS EN 17077:2018EN 17077:2018 (E) 6 3.5 propagation movement of the combustion front along the train 3.6 glowing combustion with light emission without visible flame 3.7 smoulderin

40、g combustion without light emission 4 Principle of the test method A representative sample of the test substance is placed at ambient temperature on a heat insulating surface and ignition is attempted. The air flow moving along the length of the dust train is kept constant during the test. Since the

41、 test result may depend on the temperature of the dust sample tests at elevated temperatures could be necessary (see Annex A). For melting substances the sample preparation or test equipment shall be modified (see 7.5). 5 Test equipment 5.1 General The test apparatus is placed in a laboratory fume c

42、upboard which creates an air flow of approximately 0,2 m/s to 0,4 m/s in the propagation direction of the reaction next to the surface of the dust. The slight overflow with air is necessary, since the sample may produce inert gas after contact with the ignition source. The inert gas can influence th

43、e burning behaviour of the dust. NOTE The higher air velocities and/or temperatures present in filter systems or dryers can change the burning behaviour when compared to that determined by the standard test procedure. Varying test conditions can simulate technical process conditions. If modified tes

44、t conditions lead to a different burning class then this should be mentioned in the test report along with a description of how test conditions have deviated from the standard. 5.2 Test apparatus 5.2.1 Board method The tests are performed on a clean, non-combustible thermal isolating board, or tile,

45、 with a plane surface placed in a laboratory fume cupboard. A mould (20 2) mm width, (10 1) mm height and min. 40 mm length is used to form a triangular powder train (see Figure 1). BS EN 17077:2018EN 17077:2018 (E) 7 Dimensions in millimetres Figure 1 Mould for forming powder train NOTE 1 Different

46、 plate materials are possible (e.g. ceramic, marble, fibre insulation board). NOTE 2 Boards with a textile structure yield in a higher burning classes for melting dust samples (see 7.4 and Annex B). NOTE 3 The size of the mould, apart from the length, corresponds to the UN-Test N.1 3 concerning read

47、ily combustible solids. 5.2.2 Ltolf apparatus The Ltolf Apparatus consists of a glass tube, a sample holder made out of stainless steel, a thermally insulating heat-proof support and a mould to form a powder train, see Figure 2. Key 1 support 2 sample holder (l = 80 mm 1 mm) 3 glass tube ( = 43 mm 1

48、 mm, l = 121 1 mm) 4 dust sample 5 air flow (0,2 m/s to 0,4 m/s) Figure 2 Ltolf apparatus for burning class BS EN 17077:2018EN 17077:2018 (E) 8 5.3 Ignition source The ignition source is an electrically heated glowing platinum wire with a temperature of approximately 1 000 C (e.g. diameter 1 mm, len

49、gth 86 mm 1 mm, I = 30 A 0,5 A). This is illustrated in Figure 3. Alternatively, an open flame of a burner (operating with e.g. butane, propane, natural gas) can be used. The oxygen concentration should be regulated to achieve a blue coloured triangular flame with a length of approximately 10 mm to 20 mm and a diameter of 2 mm to 3 mm in the middle of the flame. See Figure 4. The temperature at the tip of the inner blue flame should be approximately 1 000 C. Key 1 platinum wire: total length 86 mm 1 mm l135 mm 1 mm,