GB 15605-2024 Specifications for pressure venting of dust explosion
1 Scope
This document specifies the technical requirements for pressure venting of dust explosion, and the installation, use and maintenance requirements of explosion venting devices, and also describes the corresponding verification methods.
This document is applicable to the explosion venting of processing equipment and facilities in area subject to dust explosion hazards.
This document is not applicable to the following areas with dusts, namely, those in coal mines and with fireworks, explosives and powders, strong oxidants and toxic or corrosive dust.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions 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.
GB 15577 Safety regulations for dust explosion prevention and protection
GB/T 15604 Terminology for dust explosion prevention
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 15604 and the following apply.
3.1
dust containment processing equipment
processing equipment (including containers and pipes) in which the mixture of combustible dust and air is available
3.2
explosion venting
method of protecting the container by opening the pre-designed venting port to release unburned mixture and combustion products and prevent pressure rise beyond the design strength
3.3
reduced explosion overpressure
pred
pressure peak at which an explosion occurs within the protected processing equipment after explosion reduction measures have been taken
Note: If the explosion reduction measure of explosion venting is taken, the reduced explosion overpressure is also called explosion venting pressure.
3.4
maximum reduced explosion overpressure
pred,max
maximum value of the reduced explosion overpressure (3.3) measured by systematically changing the concentration of combustible dust
3.5
static activation pressure
pstat
pressure at which the explosion venting device is opened by a slow increase in pressure
Note: The unit of static activation pressure is MPa.
3.6
geometric venting area
AV
minimum flow cross-sectional area of the venting port during explosion venting, considering the reduction of flow cross-sectional area
Note: It includes back pressure support device, restraint device and residual components after explosion venting.
3.7
effective venting area
AE
geometric venting area of the baseline venting element achieving the same venting effect for explosion venting devices with inertia
Note: The "same venting effect" is measured by the maximum reduced explosion overpressure pred,max achieving the same effect.
3.8
required vent area
A
vent area required for explosion venting when the explosion venting efficiency is an ideal value (EF=1)
3.9
venting efficiency
EF
ratio of effective venting area to geometric venting area
Example: The geometric venting area of an explosion door is 1m2. If the actual test shows that its venting effect is consistent with that of a baseline venting element of 0.7m2, its effective venting area is 0.7m2 and its venting efficiency is 0.7.
Note 1: It indicates the dimensionless number that reduces the venting effect of the explosion venting device due to the presence of inertia or flame quenching element.
Note 2: The venting efficiency of the baseline venting element is 1.
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Technical requirements 4.1 General requirements 4.2 Design and selection 4.3 Requirements for explosion venting device 5 Installation, use and maintenance 5.1 Installation and use 5.2 Inspection, maintenance and repair 6 Verification methods Annex A (Normative) Calculation of container venting area A.1 General requirements A.2 Explosion venting of separate containers A.3 Special dust cloud conditions A.4 Explosion protection of interconnected container systems A.5 Effect of venting duct A.6 Heterogeneous mixture Annex B (Informative) Examples of venting area calculation B.1 Calculation of venting area of container and silo B.2 Effect of venting duct on design strength of container B.3 External reach of flame and external peak overpressure of venting container B.4 Recoil force Annex C (Informative) Determination of length diameter ratio of protected container/silo during venting area calculation C.1 General C.2 Top venting of cylindrical container C.3 Side venting of cylindrical container C.4 Top venting of cylindrical container with cone C.5 Side venting of cylindrical container with cone (with venting port close to the cone) C.6 Side venting of square container with cone C.7 Side venting of square container with cone (with venting port close to the cone) C.8 Volume calculation for square cone and circular cone C.9 Side venting of square bag filter with cone (hopper) (with venting port close to the cone) Annex D (Informative) Additional influence of container explosion venting and its protection D.1 Flame range D.2 External influence of pressure D.3 Recoil force D.4 Vacuum breaker Annex E (Informative) Guide plate Annex F (Informative) Special considerations on explosion venting design of dust collector F.1 Bag filter with outside filtration F.2 Cyclone dust collector Annex G (Informative) Explosion venting design of pipe Annex H (Informative) Explosion venting design of bucket elevator H.1 Explosion venting design of bucket elevator with unknown strength H.2 Double-legged square barrel bucket elevator H.3 Double-legged cylinder bucket elevator Bibliography
