AQ 4273-2016 English PDF (AQ4273-2016)

This Standard specifies the requirements for explosion-proof measures, maintenance and overhaul, detection and verification of dedusting system that are used in dust explosion hazardous area. This Standard applies to the design, manufacturing, installation, acceptance, use and maintenance of dedusting system that are used in dust explosion hazardous area.

AQ 4273-2016
GB
WORK SAFETY INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
ICS 13.100
C 65
RECORD NO.. 56078-2016
Safety Specifications for Dedusting System
Used in Dust Explosion Hazardous Area
ISSUED ON. AUGUST 29, 2016
IMPLEMENTED ON. MARCH 1, 2017
Issued by. State Administration of Work Safety of the People’s Republic of China
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative References ... 4
3 Terms and Definitions ... 5
4 General ... 6
5 Deduster ... 8
6 Dust Hoods and Dust Cabinets ... 12
7 Air-Duct ... 12
8 Fans ... 14
9 Explosion-proof Device ... 14
10 Electrical Safety and Anti-Static Measures ... 16
11 Deduster and Air-duct’s Layout and Safety Measures ... 16
12 Dust Cleaning ... 18
13 Maintenance-Overhaul, Testing and Verification ... 19
Foreword
All the technical content of this Standard is compulsory, except Clauses 1, 2 and 3, 5.1.4c), 5.1.7c), 6.3.7.1.1, 7.1.6, 7.1.7, 9.3a).
This Standard was drafted in accordance with the rules given in GB/T 1.1-2009. This Standard was proposed by the Fourth Supervision Division of the State Administration of Work Safety.
This Standard shall be under the jurisdiction of Technical Subcommittee 5 on Dust Explosion Prevention of National Technical Committee 288 on Work Safety of Standardization Administration of China (SAC/TC 288/SC 5).
The drafting organizations of this Standard. Guangdong Jinfangyuan Safety Technology Testing Co., Ltd., Sinosteel Corporation Wuhan Safety and Environmental Protection Research Institute. Safety Enginerring Research Center of NEU, Guangzhou Gan Feng Machinery Equipment Co., Ltd., Guangzhou Tongsheng
Environmental Protection Technology Co., Ltd.
The main drafters of this Standard. Meng Xianwei, Xu Guoping, Li Gang, Zhao Danli, Meng Tingting, Zhou Jinbiao, Zhang Wei, Feng Gang, Feng Guishen, Luo Xingyue, Xiao Gongzeng.
Safety Specifications for Dedusting System
Used in Dust Explosion Hazardous Area
1 Scope
This Standard specifies the requirements for explosion-proof measures, maintenance and overhaul, detection and verification of dedusting system that are used in dust explosion hazardous area.
This Standard applies to the design, manufacturing, installation, acceptance, use and maintenance of dedusting system that are used in dust explosion hazardous area. This Standard does not apply to dedusting system that are used in production sites of chemicals, mining, tunneling, fireworks and firecrackers, and commercial explosive materials.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition dated applies to this document. For undated references, the latest edition of the referenced documents (including all amendments) applies to This Standard.
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. Selection 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 Deduster in Dust Explosion Hazardous Area
GB 50019, Code for Design of Heating Ventilation and Air Conditioning in Industrial Buildings
GB 50057, Design Code for 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 Standard, the following terms and definitions apply. 3.1
dust
small solid particles in the atmosphere which settle out under their own weight, but which may remain suspended in air for some time.
3.2
combustible dust
dust that can burn or glow in air and could form explosive mixtures with air at atmospheric pressure and normal temperatures.
3.3
dust explosion hazardous area
the sites at where combustible dust, combustion-supporting gas or ignition source is present.
3.4
dedusting system
a system which is used to gather the solid particles in gas- and solid-phase flows, comprising dust collection hood or dust collection cabinet, air hose, fan, dust catcher and control device.
3.5
explosion-proof device
the device which adopt the technique of prevention and control of dust explosion, to prevent the formation of dust clouds or possible ignition sources and put combustible If there exists toxic, corrosive dust and combustible dust, the deduster and air-duct shall not adopt explosion-venting device for pressure release; it shall select the explosion-suppression device that can charge fire extinguishing gas or powder media into the deduster and air-duct to extinguish flames.
4.3 The box of the deduster shall meet the following requirements.
a) The box is made of a steel metallic material, or select flame-resistant materials and take anti-static measures if other materials are used; it shall not use aluminium metallic materials.
b) The design strength of the box shall be able to withstand the maximum explosive pressure generated after explosion-proof measures are adopted; and the box installed in buildings shall adopt steel metallic materials and welding structures. c) The included angles between the box-plates of a square-box shall be arc-treated. d) The internal surface of the box shall be smooth; the box made of steel metallic material shall be treated for rust-proofing; aluminium coating shall not be used. 4.4 The operating conditions of the dry deduster shall include continuous dust discharging and continuous dust conveying. It should not adopt settling chamber to perform dust treatment.
4.5 The deduster used in explosion hazardous areas of aluminium-magnesium dust and wooden product dust shall work under negative pressure conditions; for other dust explosion areas, if dedusting system adopts positive pressure to blow dust, then it shall adopt reliable measures to prevent the ignition sources.
4.6 Aluminium-magnesium dust shall not share the same dedusting system with iron dust and other kinds of combustible dust; and the dedusting system shall not connect with air-duct and equipment that carry combustible gas, high-temperature gas, smoke dust and other industrial gases.
4.7 The entry of sparks into the air-duct and deduster of the dedusting system is not allowed. For the production-processing system that exists suction of sparks into the air-duct through dust hood or dust cabinet, it shall adopt the measures to block sparks to enter into the air-duct and deduster.
4.8 The dedusting system shall be set up with control device meeting the following requirements.
a) Start and stop. The dedusting system shall be started before the production- processing system. When the production-processing system is stopped, the dedusting system shall be delayed for 10 min before being stopped.
b) Protection interlock. The dedusting system shall be set up with protection interlocking device. When the monitoring device give an acoustic-optical alarm c) Dust conveying device should adopt pneumatic dust conveying; it should not adopt scraper dust conveyors and spiral dust conveyors.
d) The safety requirements for pneumatic dust conveying.
-- The air-volume and air-velocity of the designed pneumatic dust conveying duct shall be calculated based on that no dust will block the duct and the duct temperature is not higher than 70°C.
-- Set up air pressure monitoring alarm device which give acoustic-optical alarm signals when the air pressure is lower than the design value.
-- Set up dust discharging openings every 6 m of horizontal dust conveying duct and in the positions where the angle of air-duct elbow is greater than 45°. The dust discharging openings shall be sealed-closed in the non-discharging state. The design strength shall be greater than the design strength of the air-duct. -- In the positions where the angle of air-duct’s elbow is greater than 45°, set up observation window to monitor the dust flowing in the duct. The design
strength shall be greater than the design strength of the air-duct.
-- For the duct of the length greater than 10 m, set up explosion-proof device as specified in 4.2.
e) The safety requirements for scraper dust conveying.
-- Use the sealed-closed dust conveying method. Do not discharge dust to the outside of the scraper conveyor during the dust conveying operation.
-- The operating speed of the designed scraper dust conveyor shall be calculated based on that dust will not block in the scraper dust conveyor.
-- Set up the monitoring-alarm device for the operating speed of the scraper dust conveyor; and they shall give acoustic-optical alarm signals when the
operating speed deviates from the set value.
-- The scraper shall be made of flame-resistant and antistatic materials. -- Set up manholes for dust discharging, overhauls and repairs every 6 m of the scraper dust conveyor. The manholes shall be sealed-closed when dust
discharging, overhauls and repairs are not done.
-- Set up observation window to monitor the operating state of the scraper dust conveyor.
-- If the conveying length of the scraper dust conveyor is greater than 10 m, set up explosion-proof device as specified in 4.2.
f) The safety requirements for spiral...