This standard is applicable to the engineering design, production management, storage and transportation of powdery products in dangerous places of dust explosion.

This standard does not apply to mines, fireworks and explosive dust places. The clauses in the following documents become the clauses of this standard by reference. All subsequent modifications (excluding errata) or revisions of dated reference documents are not applicable to this standard. However, parties who have reached an agreement according to this standard are encouraged to study whether the latest versions of these documents can be used. For undated reference documents, the latest edition is applicable to this standard.

GB/T 1 165 1 labor protection articles selection rules

GB 12476. 1 0 electrical equipment for combustible dust environment.

Part l: electrical equipment protected by enclosure and limited in surface temperature.

Section 1: Technical Requirements for Electrical Equipment (Idec61241-1:1999)

GB/T 15605 dust explosion pressure relief guide (NEQ NFPA 68)

GB/T 179 19 Explosion-proof guidelines for dust collectors used in hazardous places of dust explosion.

GB/T 18 154 safety technical requirements for monitoring explosion suppression devices.

Code for Lightning Protection Design of Buildings (GB50057)

GB50058 Code for Design of Electrical Installations in Explosive and Fire Dangerous Environments

The following terms and definitions in GBJ 16 Code for Fire Protection Design of Buildings are applicable to this standard.

3. 1 combustible dust

Dust that can react violently with gaseous oxidants (mainly air) under certain conditions.

3.2 areas with dust explosion danger in dust explosion danger places

Places where combustible dust and gaseous oxidants (mainly air) exist.

3.3 inerting

The technology of filling enough inert substances in places where there is a danger of dust explosion to make the dust mixture lose its explosiveness.

Explosion suppression

When an explosion occurs, the flame is extinguished by physical and chemical action, so that unexploded dust no longer participates in the explosion control technology.

3.5 Explosion-proof (fire prevention)

In the channel containing combustible dust, explosion suppression technology is set to prevent the flame from passing, block and eliminate waves, so as to block the explosion in a certain range.

3.6 Dust explosion discharge

When an explosion occurs in a confined space with dust and mainly air, before the explosion pressure reaches the ultimate strength of the confined space, the high-temperature and high-pressure combustion products and unburned substances generated by the explosion leak to the non-dangerous direction through the weak part of the confined space, so that the confined space is not damaged.

3.7 Secondary explosion and subsequent explosion

When the dust explodes, the shock wave of the initial explosion will raise the deposited dust again, forming a dust cloud, which will be ignited by the subsequent flame, leading to continuous explosion. 4. 1 New construction, reconstruction and expansion projects of enterprises with dust explosion danger shall comply with the provisions of this standard. Existing enterprises that do not meet the requirements of this standard should formulate safety technical measures plans.

4.2 The enterprise should know whether there is a dangerous place for dust explosion in the enterprise, and take effective measures to prevent and control dust explosion.

4.3 The enterprise shall formulate the detailed rules for the implementation of the dust explosion-proof safety checklist of the enterprise according to this standard and the characteristics of its own dust explosion-proof dangerous places, and carefully carry out the dust explosion-proof inspection according to the safety checklist. Enterprises should check at least once every quarter, and workshops (or sections) should check at least once a month.

4.4 Enterprises should conscientiously do a good job in safety production and dust explosion-proof education, popularize dust explosion-proof knowledge and safety laws and regulations, and make employees understand the danger degree and explosion-proof measures of dust explosion dangerous places in their enterprises; Workers in dangerous positions should receive special safety technology and business training, and they can only take up their posts after passing the examination.

4.5 In the dangerous place of dust explosion, all kinds of unproductive open flames should be put an end to.

4.6 Without the approval of the competent department of safety, equipment and facilities such as safety, ventilation and dust removal, dust explosion prevention and dust explosion control shall not be replaced or stopped. 5. 1 buildings (structures) with dust explosion danger or combustible dust should be separated from other buildings (structures), and their fire protection distance should comply with the relevant provisions of GBJ 16.

5.2 The building should be a single-story building with a light roof.

5.3 The structural requirements of multi-storey buildings are as follows:

5.3. 1 frame structure is suitable for multi-storey buildings;

5.3.2 For buildings that cannot adopt frame structure, explosion-proof doors that meet the requirements shall be set on the wall;

5.3.3 If windows or other openings are used as explosion vents, check and ensure that they can effectively vent during explosion.

5.4 Process equipment with explosion danger should be set in the open air outside the building; If there is a danger of dust explosion in the workshop, the process equipment should be located at a higher position in the building and close to the external wall.

5.5 Beams, supports, walls and equipment shall have a surface structure that is easy to clean.

5.6 The requirements for evacuation routes are as follows:

5.6. 1 The working area should have an evacuation passage. The number and location of evacuation passages shall comply with the relevant provisions of GBJ 16;

5.6.2 The evacuation route should have obvious road signs and emergency lighting.

5.7 Process equipment with explosion danger should be set in the open air outside the building. 6. 1 Prevent spontaneous combustion of powder

6. 1. 1 Spontaneous combustion of hot powder should be cooled to normal storage temperature before storage;

6. 1.2 Under normal storage conditions, when a large amount of bulk powder with spontaneous combustion is stored, the temperature of the powder should be continuously monitored; When temperature rise or gas evolution is found, measures should be taken to cool the powder;

6. 1.3 The discharging system should have measures to prevent powder aggregation.

6.2 Prevent open flames and hot surfaces from catching fire.

6.2. 1 The following provisions shall be observed when working with naked flame in dust explosion dangerous places:

—— Approved by the person in charge of safety, and obtained the hot certificate;

—— Before the operation with open flame begins, the combustible dust in the workplace with open flame shall be removed, and sufficient fire extinguishing equipment shall be provided;

—— The open flame operation part shall be separated or separated from other parts;

-No dust shall enter the open flame workplace during the open flame operation and during the cooling period after the operation.

6.2.2 The allowable surface temperature of the equipment or device (such as light source and heating source) in direct contact with dust shall be lower than the minimum ignition temperature of the corresponding dust;

6.2.3 In places with combustible dust, the transmission mechanism of equipment and devices shall meet the following requirements:

—— Bearings of process equipment shall be dustproof and sealed; If overheating is possible, a detector that can continuously monitor the bearing temperature should be installed;

-Improper belt drive; If belt drive is used, speed difference sensor and automatic anti-skid protection device should be installed; When sliding friction occurs, the protection device should be able to ensure automatic stop.

6.3 Prevention of Electric Arc and Electric Spark

6.3. 1 In the dangerous place of dust explosion, corresponding lightning protection measures should be taken according to the relevant provisions in GB50057;

6.3.2 When there is electrostatic danger, the following provisions shall be observed:

6.3.2. 1 All metal equipment, device shells, metal pipes, supports and parts shall be directly grounded by anti-static; If it is inconvenient or the process does not allow direct grounding, it can be indirectly grounded through electrostatic conductive materials or products;

6.3.2.2's instruments directly used for loading powder and pipelines (belts) for conveying powder should be made of metal or antistatic materials;

All metal pipe joints (such as flanges) in 6.3.2.3 should be bridged;

6.3.2.4 operators should take anti-static measures;

6.3.2.5 should not use the method of metal conductor directly grounding or shielding contact with high-speed flowing powder to eliminate static electricity;

6.3.3 The electrical equipment used in the hazardous places of dust explosion shall comply with the relevant provisions of GB 12476. 1+0;

6.3.4 The power design of dust explosion dangerous places shall be implemented according to the relevant provisions of GB50058.

6.4 Prevent sparks from friction and collision.

6.4. 1 When sparks generated by collision can ignite dust clouds, measures should be taken to prevent collision, and explosion-proof tools should be used for maintenance;

6.4.2 Magnets, pneumatic separators or screens that can remove impurities from mixed materials should be installed at the feed of the process flow to prevent impurities from colliding with equipment;

6.4.3 Effective measures should be taken to prevent aluminum, magnesium, titanium, zirconium and other metal powders or powders containing these metals from rubbing against stainless steel to generate sparks;

6.4.4 There are no protective measures equivalent to open flame operation. Rotating grinding wheels and rotating cutting discs should not be used for grinding and cutting.

6.5 inerting

In the process equipment for producing or treating combustible powder, if the safety cannot be guaranteed after taking the above measures, the inerting technology should be adopted.

6.6 Ventilation and dust removal

6.6. 1 It is advisable to set up a relatively independent dust removal system according to process segments;

6.6.2 Dust covers shall be installed at all dust producing points;

6.6.3 There should be no dust deposition in the air duct;

6.6.4 The installation, use and maintenance of the dust collector shall comply with the relevant provisions of GB/T 179 19. 7. 1 segmentation and isolation

7. 1. 1 The connection of process equipment shall ensure that all equipment can be easily separated and moved, and there is no open flame operation;

7. 1.2 When designing process equipment, technical isolation should be considered.

7.2 Implement protective parking during explosion.

According to the size of the workshop, several interlocking power control boxes should be installed; In case of emergency, all motors should be cut off in time.

7.3 Explosion-proof

7.3. 1 explosion suppression device shall be used for protection;

7.3.2 If monitoring explosion suppression device is adopted, it shall comply with the provisions of GB/T 18 154.

7.4 Restrain explosion pressure

When producing and processing powder that can cause explosion, all process equipment should be able to withstand the overpressure caused by internal explosion without explosion suppression device and pressure relief measures; At the same time, connecting parts (such as pipes, flanges, etc.). ) All kinds of process equipment should also have the same strength as the equipment itself; Explosion-proof devices should be installed at the joint of high-strength equipment and low-strength equipment.

7.5 Explosion-proof

7.5. 1 When the strength of process equipment is insufficient to withstand the overpressure caused by internal dust explosion under its actual working conditions, an explosion vent shall be set. The size of explosion-proof door shall conform to GB/T15605;

7.5.2 For process equipment with on-line pipeline, the generally recommended design index should be able to withstand at least 0. 1MPa internal overpressure. 8. 1 process equipment joints, inspection doors, baffles, explosion-proof hole covers, etc. Should be tightly closed.

8.2 Cleaning requirements for special places

8.2. 1 In special places where dust leakage cannot be completely prevented (such as places where powder enters and exits process equipment), effective dust removal measures should be taken;

8.2.2 Effective dust prevention measures should be taken in places where powder is manually loaded;

8.2.3 Packaging places should be cleaned regularly.

8.3 cleaning

8.3. 1 All workshops and warehouses that may accumulate dust shall be cleaned in time;

8.3.2 Compressed air should not be used for purging.

8.4 Fire extinguishing

8.4. 1 Fire extinguishing agent should be correctly selected according to the physical and chemical properties of dust;

8.4.2 When putting out the fire, dust and fog should be prevented;

8.4.3 If combustible materials can generate explosive gas when meeting water, they should not be put out with water. 9. 1 personal protection

9. 1. 1 Production personnel shall use labor protection articles in accordance with the relevant provisions of GB 1 165 1;

9. 1.2 places where inert gases are used or toxic gases may be released in the process flow shall be equipped with respiratory protection devices that can ensure the safety of operators;

9. 1.3 In the workplace, production personnel should not wear chemical fiber products and underwear.

9.2 rescue

9.2. 1 The enterprise shall prepare an emergency rescue plan containing dust explosion and report it to relevant departments for the record;

9.2.2 Organize all employees to conduct drills on fire fighting and emergency rescue plans.