Six requirements for enterprises involving explosive dust

1. Major accident hidden danger identification criteria "should be known to all"

The following is Article 11 of the "Standard for Determining Major Accident Hidden Dangers in Industrial and Trade Enterprises", and industrial and trade enterprises that have one of the following situations and pose a risk of dust explosion should be determined as major accident hidden dangers (related enterprises should strictly check and rectify themselves):

(1) Explosion-proof dust hazards are located in multi-story buildings (structures) that are not frame construction, or where there are employee dormitories, conference rooms, offices, rest rooms, and other personnel gathering places within the explosion-proof dust hazards;

(2) Different categories of combustible dust, combustible dust and flammable gas, which can intensify the risk of explosion, share a set of dust removal system, or different buildings (structures), different fire compartments share a set of dust removal system, and the dust removal system is interconnected;

(3) The dry dust removal system has not taken any of the following explosion prevention measures: venting, inerting, or flameless explosion suppression.

(4) Aluminum-magnesium and other metal dusts' explosion-proof dust removal system uses positive pressure dust removal method, or other combustible dusts' dust removal system uses positive pressure to blow dust, but no measures such as spark detection and removal to prevent the ignition source are taken;

(5) The dust removal system uses gravity settling chamber for dust removal, or uses dry roadway-type structure as the dust removal air duct;

(6) Aluminum-magnesium and other metal dusts, wood dusts dry dust removal systems without airtight ash discharge device;

(7) Explosion-proof electrical equipment in dust explosion hazard areas divided into Zone 20 such as dust collectors and dust bins does not meet the explosion-proof requirements;

(8) In front of process equipment that is prone to produce mechanical ignition sources, such as crushing, grinding, and pelletizing, there is no device to remove iron, stone, and other debris, or the air duct connected to the sanding machine in wood processing enterprises does not have a device to detect and eliminate sparks;

(9) Metal powder collection, stacking, and storage areas for self-igniting materials in contact with moisture have not taken measures to prevent the accumulation of hydrogen, such as ventilation, or dry collection, stacking, and storage areas have not taken measures to prevent water and moisture, such as waterproofing and moisture-proofing measures;

(10) Failure to implement the dust cleaning system, resulting in serious accumulation of dust at the workplace.

2. Dust removal process "should be wet to the end"

(1) The grinding and polishing processes in the processing of aluminum, magnesium and other metal products should use wet dust removal in places where combustible metal dust is generated.

(2) The water storage tank (box) and water quality filtration tank (box) for circulating water collected by the wet dust removal method shall not be sealed and shall be well ventilated. The amount of water and water quality shall meet the requirements of the "Safety Technical Specification for Explosion Prevention of Mechanical Processing Dust of Aluminum and Magnesium Products" and the "Safety Technical Specification for Dust Explosion Hazardous Places Dust Removal System", and the water level shall be checked in time, the water quality shall be monitored and the water for dust removal shall be replaced, and the mud in the filtration tank (box) shall be cleaned in time. For the single machine wet dust removal device, the device shall be cleaned at least once per shift, and the dust removed shall be transported away in time.

(3) It is strictly forbidden to grind or dustify with water, and to operate without water. The water supply system must be equipped with water level and flow rate monitoring and alarm devices, which must be interlocked with the main equipment to ensure that the machine stops in case of water shortage.

3. The interconnection pipeline should be "disassembled to the fullest extent".

(1) The dust explosion hazard area dust removal system should not be connected to the air duct and equipment with flammable gas, high temperature gas or other industrial gas; the dust removal system should be set up relatively independently according to the process section (area); the dust removal system in different fire compartments should not be connected.

(2) Sanding and polishing workstations shall not be interconnected through collection pipes in principle; those using single-machine dust removal and equipment body dust removal shall not be interconnected through pipes.

4. Personnel involved in powder operations should be reduced as much as possible.

(1) Reasonably plan the production process layout, reduce the number of people involved in powder operations during a single shift, and isolate areas through measures such as building firewalls, ensuring that the number of people in powder explosion hazard areas does not exceed 9 in principle.

(2) The number of operators in the dust explosion hazard area should be strictly controlled, and no rest rooms, conference rooms and other densely populated places should be set up. The fire safety distance from other factory buildings, warehouses, staff dormitories, etc. should not be less than the distance specified in the "Building Design Fire Protection Code" (GB50016).

5. Dust should be swept away completely.

(1) Enterprises should formulate dust cleaning systems that include the scope of cleaning, cleaning methods, cleaning cycle, etc., for dust explosion hazard places. All areas and equipment facilities (work site, equipment interior, dust removal pipeline dust removal equipment) where dust may accumulate should be thoroughly and regularly cleaned.

(2) Keep the workplace and the body of the dust collector well ventilated to prevent the accumulation of hydrogen. Timely clean the dust mud, and do not use compressed air for sweeping, it is better to use negative pressure suction to clean according to the characteristics of the dust.

(3) Metal powders that self-ignite in the presence of moisture should not be cleaned using water spraying to increase humidity. The collected powder should be handled as per regulations.

6. Monitoring and early warning system "should be connected"

(1) Aluminum and magnesium metal powder and wood powder enterprises with more than 10 people in a single shift should connect to the dust monitoring and early warning system, and improve the ability to perceive, deal with and prevent risks and hidden dangers in the field of dust explosion.

(2) Enterprises should regularly clean the dust accumulated on the workplace and related equipment and facilities, and check in the monitoring and early warning system.