Detail of AQ 4273-2016

Introduction of AQ 4273-2016

All the technical contents, except Clauses 1, 2 and 3 as well as 5.1.4c), 5.1.7c), 6.3, 7.1.1, 7.1.6, 7.1.7 and 9.3a), of this standard are compulsory. This standard is developed in accordance with the rules given in GB/T 1.1-2009. This standard was proposed by the State Administration of Work Safety of the People's Republic of China. This standard is under the jurisdiction of SAC/TC 288/SC 5 Subcommittee on Dust Explosion Prevention and Protection of National Technical Committee on Safety Production of Standardization Administration of China. Drafting organizations of this standard: Guangdong Jinfangyuan Safety Technology Testing Co., Ltd., Sinosteel Wuhan Safety & Environmental Protection Research Institute, Safety Engineering Research Center of NEU, Guangzhou Ganfeng Machinery Equipment Co., Ltd. and Guangzhou Tongsheng Environmental Protection Technology Co., Ltd. Chief drafters of this standard: Meng Xianwei, Xu Guoping, Li Gang, Zhao Danli, Meng Tingting, Zhou Jinbiao, Zhang Wei, Feng Gang, Feng Guishen, Luo Xingyue and Xiao Gongzeng. Safety specifications for dedusting system used in dust explosion hazardous area 1 Scope This standard specifies the requirements for explosion prevention measures, and maintenance, repair, and testing and verification of the dedusting system used in dust explosion hazardous area. This standard is applicable to the design, manufacturing, installation, acceptance, application and maintenance of the dedusting system used in dust explosion hazardous area. This standard is not applicable to the dedusting system used in production sites of chemical industry, mining, tunnel, fireworks and crackers and industrial explosive materials. 2 Normative references The following documents are indispensable for the application of this standard. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB 2894 Safety signs and guideline for the use GB 7231 Basic identification colors and code indications and safety sign for industrial pipelines GB 12158 General guideline for preventing electrostatic accidents GB 12476.1 Electrical apparatus for use in the presence of combustible dust - Part 1: General requirements GB 12476.2 Electrical apparatus for use in the presence of combustible dust - Part 2: Selected and installation GB 15577 Safety regulations for dust explosion prevention and protection GB/T 15605 Guide for pressure venting of dust explosions GB/T 16758 The classification and technical specification of exhaust hood GB/T 17919 Directives for dust explosion protection for dust collectors in dust explosion hazardous area GB 50019 Code for design of heating ventilation and air conditioning GB 50057 Code for design protection of structures against lightning GB 50058 Code for design of electrical installations in explosive atmospheres AQ 7005 Safety requirements for the use of woodworking machinery 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 dust a kind of small solid particles, which may deposit in the air due to deadweight, or also may suspend in the air for a certain period 3.2 combustible dust dust that may burn or flamelessly burn in the air and may form explosive mixture with air at the atmospheric pressure and normal temperature 3.3 dust explosion hazardous area area where combustible dust, combustion-supporting gas and ignition sources exist 3.4 dedusting system the device for collection of solid particles in gas-solid two-phase flow, consisting of dust hood or cabinet, duct, fan, deduster and control device 3.5 explosion-proof devices devices that are intended to avoid formation of dust cloud or potential ignition source and enable the combustible dust to lose the combustion and explosion actions by adopting the dust explosion prevention and control technologies, such as explosion venting, inerting, flame-proof and explosion suppression devices 4 General 4.1 Dust explosion hazards of production and processing system shall be identified and evaluated, and the selection of the deduster shall meet the following requirements: a) If dry deduster is adopted for dedusting, bag-type outward filtering and (or) cyclone dedusting technology shall be adopted. b) If wet deduster is adopted for the dedusting in mechanical processing of aluminum and magnesium products as well as for the case that wet deduster is appropriate, water washing or water curtain dedusting technology shall be adopted. c) Electric deduster shall not be adopted. d) Settling chamber-based gravity settlement dedusting mode shall not be adopted for the dedusting system; and dry roadway structure shall not be adopted as dedusting duct. e) Adoption of single-machine filter bag deduster for dedusting in machining of wooden furniture shall meet the requirements of AQ 7005. 4.2 Dry dedusting system shall be provided with dust explosion prevention and control measures according to the explosion characteristics of the combustible dust, and one or more of the following explosion-proof devices reducing explosion hazards shall be adopted: a) Explosion venting device. Before the explosion pressure reaches the anti-detonation strength of the deduster and duct, explosion venting device shall be adopted to vent the explosion product and protect the deduster and duct from damage. b) Inerting device. The deduster is filled with inert gas or powder to make the combustible dust lose the explosivity. c) Flame-proof device. The duct is equipped with flame-proof device to block the flame and explosion wave within certain limits. d) Explosion suppression device. The duct and (or) deduster are equipped with explosion suppression device, so that the duct and (or) deduster can be filled with physical and chemical fire extinguishing media at the moment of the explosion to suppress the development or spreading of the explosion. For the deduster and duct containing toxic or corrosive dust or fuel dust, explosion venting device shall not be adopted for pressure relief, and such explosion suppression device that fills the deduster and duct with fire extinguishing gas or powder shall be selected. 4.3 Box of the deduster shall meet the following requirements: a) The box shall be made of steel metal materials. If it is made of other materials, it shall be made of flame-retardant materials and also be provided with anti-static measures; in any case it shall not be made of aluminum metal materials. b) The design strength of the box shall be enable the box to withstand the maximum explosion pressure generated after explosion prevention measures are taken; for the box arranged in the structures, it shall be made of steel metal materials and be assembled by welding. c) Included angle between box boards of square box shall be subject to arcing treatment. d) The internal surface of the box shall be smooth; the box made of steel metal materials shall be provided with anti-rust measures and aluminum paint shall not be used. 4.4 The operating conditions of the dry deduster shall be continuous dust discharging and conveying. The settling chamber should not be used for dust treatment. 4.5 The dedusters used in the dust explosion hazardous areas of the aluminum and magnesium dusts and wooden product dusts shall be operating in the state of negative pressure; for the dedusting systems used in other dust explosion hazardous areas, if positive pressure is adopted for blowing of the dust, reliable measures against the ignition sources shall be taken. 4.6 Aluminum and magnesium dusts shall not share the same dedusting system with iron dust and other kinds of combustible dust, and the dedusting system shall not be connected with the duct and equipment containing such industrial gas as combustible gas, high-temperature gas and smoke dust. 4.7 The duct and deduster of the dedusting system shall be free from any spark; for the production and processing system with such hazard that the spark is inhaled into the duct via the dust hood or cabinet, measures shall be adopted to prevent the spark from entering into the duct and deduster. 4.8 Dedusting system shall be equipped with control devices in accordance with the following requirements: a) Startup and shutdown. The dedusting system shall be started ahead of the production and processing system and be shut down at least 10min later than the production and processing system. b) Protective interlocking. The dedusting system shall be equipped with protective interlocking device; where the monitoring device sends out an audible and visual alarm signal and the flame-proof and explosion suppression devices start, the protective interlocking device shall start the control protection simultaneously. 4.9 Monitoring and alarm device of the dedusting system shall be installed at positions convenient for observation. 4.10 Dedusting system shall be provided with safety signs according to the requirements of GB 2894 and the duct shall be provided with safety signs, identification color or code identification according to the requirements of GB 7231.

Contents of AQ 4273-2016

Foreword I 1 Scope 2 Normative references 3 Terms and definitions 4 General 5 Deduster 6 Dust hood and cabinet 7 Duct 8 Fan 9 Explosion-proof devices 10 Electrical safety and anti-static measures 11 Arrangement and safety measures of the deduster and duct 12 Dust cleaning 13 Maintenance, repair, testing and verification