1 - AS 1681-2002 SAFETY REQUIREMENTS FOR ELECTRICALLY HEATED TYPE 1 OVENS IN WHICH FLAMMABLE VOLATILES OCCUR
4 - PREFACE
5 - CONTENTS
6 - FOREWORD
7 - SECTION 1 SCOPE AND GENERAL
7 - 1.1 SCOPE
7 - 1.2 OBJECTIVE
7 - 1.3 APPLICATION
7 - 1.4 REFERENCED DOCUMENTS
8 - 1.5 DEFINITIONS
8 - 1.5.1 Batch process oven
8 - 1.5.2 Continuous process oven
8 - 1.5.3 Dielectric heater
8 - 1.5.4 Flashpoint
8 - 1.5.5 Fresh air
8 - 1.5.6 Ignition temperature (of an explosive gas atmosphere)
9 - 1.5.7 Induction heater
9 - 1.5.8 Infrared heater
9 - 1.5.9 Infrared lamp heater
9 - 1.5.10 Natural atmosphere
9 - 1.5.11 Oven
9 - 1.5.12 Prepared atmosphere
9 - 1.5.13 Resistance heater
9 - 1.5.14 Type 1 oven
9 - 1.6 ELECTRICAL SAFETY REQUIREMENTS
9 - 1.7 COMPLIANCE WITH REGULATORY AUTHORITIES, REQUIREMENTS
10 - SECTION 2 CONSTRUCTION REQUIREMENTS
10 - 2.1 GENERAL REQUIREMENTS
10 - 2.1.1 Ovens and related equipment
10 - 2.1.2 Materials
10 - 2.1.3 Interior surfaces
10 - 2.1.4 Insulating materials in walls
10 - 2.1.5 Expansion
10 - 2.1.6 Doors
11 - 2.1.7 Guarding of moving parts
11 - 2.1.8 Shelves
11 - 2.2 EQUIPOTENTIAL BONDING
11 - 2.3 EXPLOSION-RELIEF VENTS
11 - 2.3.1 Basic requirements
11 - 2.3.2 Location in oven
12 - 2.3.3 Adjacent areas and obstructions
13 - 2.4 DUCTS
14 - SECTION 3 HEATING SYSTEMS
14 - 3.1 ELECTRICAL INSTALLATION
14 - 3.2 CONTROLS
14 - 3.3 RESISTANCE HEATERS
14 - 3.3.1 Construction
14 - 3.3.2 Protection against contact
14 - 3.3.3 Location
15 - 3.4 INDUCTION AND DIELECTRIC HEATERS
15 - 3.4.1 Installation
15 - 3.4.2 Construction
16 - SECTION 4 VENTILATION
16 - 4.1 DESIGN CONSIDERATIONS
16 - 4.1.1 General
16 - 4.1.2 Basis for determination of fresh air requirements
16 - 4.1.3 Air circulation
17 - 4.2 RATE OF VENTILATION
17 - 4.3 MECHANICAL VENTILATION
17 - 4.4 FRESH AIR SUPPLY
17 - 4.5 EXHAUST AIR
17 - 4.6 DAMPERS
17 - 4.7 FANS
18 - 4.8 VENTILATION CONTROLS
18 - 4.8.1 Preventilation and purging
18 - 4.8.2 Interlocks
19 - SECTION 5 MARKING
19 - 5.1 GENERAL
19 - 5.2 ADDITIONAL INFORMATION
20 - APPENDIX A - COMBUSTION CHARACTERISTICS FOR COMMON FLAMMABLE LIQUIDS
25 - APPENDIX B - METHODS FOR CALCULATION OF VENTILATION
25 - B1 INTRODUCTION
25 - B2 MEASUREMENT OF QUANTITY OF AIR EXHAUSTED FROM AN OVEN
25 - B3 AIR DILUTION
26 - B4 BASIC CALCULATION
26 - B5 AMOUNT OF VAPOUR PRODUCED PER LITRE OF SOLVENT EVAPORATED (Vm3/L)
27 - B6 AMOUNT OF AIR REQUIRED TO RENDER 1 m3 OF SOLVENT VAPOUR BARELY EXPLOSIVE (A m3/m3)
27 - B7 ESTIMATION OF VA
27 - B7.1 Calculation when either V or A is unknown
27 - B7.2 Calculation for mixed solvents
27 - B7.3 Continuous process ovens
27 - B7.4 Batch process ovens
28 - B8 SAFETY FACTOR C
28 - B9 MAXIMUM INSTANTANEOUS EVAPORATION RATE OF LIQUID SOLVENT (Q L/s or mL/s)
28 - B9.1 Continuous process oven
28 - B9.2 Batch process ovens
29 - B10 TEMPERATURE/VOLUME CORRECTION
29 - B11 EXAMPLES OF CALCULATIONS
29 - B11.1 Continuous oven
30 - B11.2 Batch oven, below 120°C
30 - B11.3 Batch oven above 120°C
33 - APPENDIX C - OVEN SAFETY DESIGN FORM