1、BS EN 746-2:2010ICS 25.180.01NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDIndustrialthermoprocessingequipmentPart 2: Safety requirements forcombustion and fuel handling systemsThis British Standard was published under the authority of the Standards Policy and
2、 Strategy Committee on 30 June 2010 BSI 2010ISBN 978 0 580 54597 9Amendments/corrigenda issued since publicationDate CommentsBS EN 746-2:2010National forewordThis British Standard is the UK implementation of EN 746-2:2010. Itsupersedes BS EN 746-2:1997 which will be withdrawn on 31 May 2011.The UK p
3、articipation in its preparation was entrusted to TechnicalCommittee MCE/3/8, Thermoprocessing equipment - Safety.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Us
4、ers are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 746-2 May 2010 ICS 25.180.01 Supersedes EN 746-2:1997English Version Industrial thermoprocessing equipment - Safety req
5、uirements for combustion and fuel handling systems Equipements thermiques industriels - Partie 2: Prescriptions de scurit concernant la combustion et la manutention des combustibles Industrielle Thermoprozessanlagen - Teil 2: Sicherheitsanforderungen an Feuerungen und Brennstofffhrungssysteme This E
6、uropean Standard was approved by CEN on 11 March 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
7、concerning such national standards may be obtained on application to the CEN 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 i
8、ts own language and notified to the CEN 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,
9、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 NORMUNG Management Centre: Avenue Marnix 17, B-1000 Br
10、ussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 746-2:2010: EEN 746-2:2010 (E) 2 Contents Page Foreword 6Introduction .71 Scope 82 Normative references 93 Terms and definitions 114 List of hazards . 205 Safety requireme
11、nts, measures and verification means 215.1 General . 215.2 Gaseous fuels . 215.2.1 Gas pipework 215.2.2 Required safety devices . 245.2.3 Combustion air and pre-purging the combustion chamber and flue passages 305.2.4 Supply of pre-mixed fuel gas/air . 325.2.5 Burners 335.2.6 Automatic burner contro
12、l systems . 375.3 Liquid fuels 395.3.1 Liquid fuel pipework . 395.3.2 Required safety devices . 425.3.3 Combustion air and pre-purging the combustion chamber and the flue passages 455.3.4 Liquid fuel atomisation 475.3.5 Burners 475.3.6 Automatic burner control systems . 495.4 Solid fuels 515.4.1 Pul
13、verised solid fuel pipework 515.4.2 Graded fuel pipework (applicable to grate burners and fluidised beds) 525.4.3 Required devices (for pulverised fuels and fluidised beds) 535.4.4 Combustion air and pre-purging of the combustion chamber and flue passages 545.4.5 Burners 545.4.6 Automatic burner con
14、trol systems (pulverised fuel) 565.5 Multiple fuels . 565.5.1 General . 565.5.2 Fuel circuit . 575.5.3 Combustion air supplies 575.5.4 Operation of the safety devices 575.5.5 Air/fuel ratio . 575.6 Oxygen or oxygen-enriched combustion air . 575.6.1 General . 575.6.2 Suitability for oxygen service 57
15、5.6.3 Sealing materials for oxygen pipework 575.6.4 Pipework 585.6.5 Pipes velocities . 585.6.6 Fittings . 585.6.7 Blow off and venting lines . 585.6.8 Manual torches 585.6.9 Safety devices against gas backflow 595.6.10 Safety devices against oxygen backflow in mixture with other substances . 595.6.
16、11 Material requirements 595.7 Design requirements for electrical and electronic equipment for control system and protective system . 595.7.1 General . 59BS EN 746-2:2010EN 746-2:2010 (E) 3 5.7.2 Requirements for protective systems . 605.7.3 Fault assessment for a hardwired protective system . 645.7
17、.4 Electrical power failure . 705.7.5 Reset . 706 Verification of the safety requirements and/or measures . 727 Information for Use . 777.1 General . 777.2 Marking . 777.3 Instruction handbook 787.3.1 General . 787.3.2 Description of equipment . 787.3.3 Inspection procedures 797.3.4 Commissioning, s
18、tart-up and operating procedures 797.3.5 Shut-down procedures . 807.3.6 Maintenance procedures 807.3.7 Documentation 80Annex A (informative) Typical Examples of IThE, Fuels and Burners 81A.1 List Machines concerned, descriptions, functions . 81A.1.1 List of IThE . 81A.2 Classification of fuels . 84A
19、.2.1 Gaseous fuels 84A.2.2 Liquid fuels 84A.2.3 Solid fuels 84A.3 Classification of burners 85A.3.1 Gaseous fuels 85A.3.2 Liquid fuels 85A.3.3 Solid fuels 85Annex B (informative) Technical terms 86Annex C (informative) Typical examples of piping and components 101Annex D (informative) Methods for bu
20、rner start-up 111Annex E (normative) Maximum allowable pressure 118Annex ZA (informative) 123Bibliography 124BS EN 746-2:2010EN 746-2:2010 (E) 4 Figures Figure 1 Block diagram of control/protective and heated system . 60Figure 2 a Example for requirements of 5.7.2 a . 61Figure 2 b Example for requir
21、ements of 5.7.2 b . 62Figure 2 c Example for requirements of 5.7.2 c . 63Figure 2 d Example for requirements of 5.7.2 d . 63Figure 3 Fault assessment for the hardwired section of a protective system . 65Figure 4 Consideration of fault tolerance time and safety time for IThE 66Figure 5 Examples for w
22、iring of fuel shut-down with hardware diversity of the disconnecting devices . 67Figure 6 Example for wiring of fuel shut-down with diverse functionality of the disconnecting devices . 68Figure C.1 Single burner equipment . 101Figure C.2a Multiple burner equipment Central pipework Example a two burn
23、ers system 102Figure C.2b Multiple burner equipment Central pipework Example b. 103Figure C.2c Multiple burner equipment Central pipework Example c . 104Figure C.3a Multiple burner equipment Zone pipework Example a . 105Figure C.3b Multiple burner equipment Zone pipework Example b 106Figure C.3c Mul
24、tiple burner equipment Zone pipework Example c . 107Figure C.4 Multiple burner equipment (burner pipework). 108Figure C.5 Central pipework for low cycling applications 109Figure C.6 Draft breaks . 110Figure D.1 Direct main burner ignition at full rate (see Table 3, Column 2, QF max 120 kW) 111Figure
25、 D.2 Direct main burner ignition at reduced ratewith slow opening valve (see Table 3, Column 3, QF max 360 kW) 111Figures D.3 and D.4 Direct main burner ignition at reduced rate with by-pass start gas supply (see Table 3, Column 4) . 112Figures D.5 and D.6 Direct main burner ignition at reduced rate
26、 with limited start gas input (see Table 3, Column 4) . 113Figures D.7 and D.8 Main burner ignition with independent pilot burner (see Table 3, Column 5, QF max 120 kW) . 114Figures D.9 and D.10 Main burner ignition with independent pilot burner (see Table 3, Column 5, QF max 360 kW) . 115BS EN 746-
27、2:2010EN 746-2:2010 (E) 5 Figures D.11 and D.12 Main burner ignition with independent pilot burner (see Table 3, Column 5). 116Figures D.13 and D.14 Main burner ignition with independent pilot burner (see Table 3, Column 5). 117Figure E.1 Piping referred to clause a) group 1 of Annex E 119Figure E.2
28、 Piping referred to clause a) group 2 of Annex E 120Figure E.3 Piping referred to clause b) group 1 of Annex E 121Figure E.4 Piping referred to clause b) group 2 of Annex E 122Tables Table 1 Maximum safety times for natural draught burners operating in open air 34Table 2 Maximum safety times for nat
29、ural draught burners operating in combustion chamber 35Table 3 Maximum safety times for forced and induced draught burners 36Table 4 Maximum safety times . 48Table 5 Materials requirements 59Table 6 Verification of the safety requirements and/or measures 72Table B.1 English German French . 86Table B
30、.2 German English French . 91Table B.3 French English German . 96BS EN 746-2:2010EN 746-2:2010 (E) 6 Foreword This document (EN 746-2:2010) has been prepared by Technical Committee CEN/TC 186 “Industrial Thermoprocessing Equipment”, the secretariat of which is held by DIN. This European Standard sha
31、ll be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 2010, and conflicting national standards shall be withdrawn at the latest by May 2011. Attention is drawn to the possibility that some of the elements of this docume
32、nt 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 supersedes EN 746-2:1997. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Associat
33、ion, 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. Following a request from CEN/TC 186, CEN has agreed to defer the date of withdrawal of EN 746-2:1997 for a transitional period of
34、12 months. 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, Icela
35、nd, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 746-2:2010EN 746-2:2010 (E) 7 Introduction This European Standard is a Type C standard as defined in EN ISO 12100-1.
36、The machinery concerned and the extent to which hazards, hazardous situations and events are covered, is indicated in the scope of this document. When provisions of this type C standard are different from those which are stated in type A or B standards, the provisions of this type C standard take pr
37、ecedence over the provisions of the other standards, for machines that have been designed and built according to the provisions of this type C standard. This Part of EN 746 assumes that the equipment is not creating any potentially explosive atmosphere and is located in a normally ventilated area. T
38、his European Standard forms one part of a series of safety standards covering Industrial Thermoprocessing Equipment (IThE). The full list of these standards is given below: EN 746, Industrial thermoprocessing equipment Part 1: Common safety requirements for industrial thermoprocessing equipment Part
39、 2: Safety requirements for combustion and fuel handling systems Part 3: Safety requirements for the generation and use of atmosphere gases Part 4: Particular safety requirements for hot dip galvanising thermoprocessing equipment Part 5: Particular safety requirements for salt bath thermoprocessing
40、equipment Part 6: Particular safety requirements for material melting, re-melting and liquid phase maintaining thermoprocessing equipment Part 7: Particular safety requirements for vacuum thermoprocessing equipment Part 8: Particular safety requirements for quenching equipment Compliance with Europe
41、an product standards e.g. EN 267, EN 12952-8, EN 12953-7 or EN 676 is not sufficient to ensure the minimum safety requirement for industrial thermoprocessing equipment. This part 2 of EN 746 shall always have priority for IThE. An IThE generally consists of the following components: processing chamb
42、er (e.g. steel construction with lining); heating system; protective system; control and instrumentation system/operator-control level. It is assumed that (IThE) will only be operated and maintained by trained personnel. BS EN 746-2:2010EN 746-2:2010 (E) 8 1 Scope This part of EN 746 together with E
43、N 746-1 specifies safety requirements for single and multiple burners that are part of Industrial Thermoprocessing Equipment. (In this standard referred to as IThE). This document deals with significant hazards, hazardous situations and events relevant to combustion and fuel handling systems that ar
44、e part of IThE as listed in Clause 4, when used as intended and under the conditions foreseen by the manufacturer. This European Standard covers: fuel pipework downstream of and including the manual isolating valve; burner(s), burner system and ignition device; safety related control system (protect
45、ive system). This European Standard applies to any oxidation with air or other gases containing free oxygen of gaseous, liquid and solid fuels or any combustion of them to release thermal energy. For thermal or catalytic post combustion and waste incineration, this European Standard applies only to
46、auxiliary burners designed to start-up and/or support the process. The pressure hazard of the piping and components covered by this standard is within the limits of maximum pressure/size relationship as described in normative Annex E. This European Standard also gives the necessary requirements for
47、the information for use. This European Standard does not cover hazards from heating generated by electricity. This European Standard does not deal with the hazards created by the release of flammable substances from the products processed in the IThE. NOTE EN 1539, Dryers and ovens, in which flammab
48、le substances are released Safety requirements This European Standard is not applicable to combustion and fuel handling systems of welding and soldering machines; up-stream of the IThE manual isolating valve. This European Standard is not applicable to electricity cabling and power cabling upstream of the IThE control panel/protective system. Noise can be a significant hazard for combustion and fuel handling systems. It is not dealt with in this standard. This European Standard is not applicable
