Prevent dust explosions!

Dust explosion is caused by combustible dust encountering heat source (open flame or high temperature) within the explosion limit range, and dust explosion is very harmful and often causes large casualties.

Five elements of dust explosion

1. Combustion-supporting gas: A certain oxygen content is the basis of dust combustion.

2. Combustible dust: dust that can be burned by oxidation reaction with combustion gas.

3. Ignition source: A high temperature heat source that can cause a sudden increase in the temperature of a local dust cloud to burn.

4. Dust Cloud: A cloud of combustible dust suspended in the air at the lower explosive limit.

5. Confined space: The dust cloud is confined to a relatively confined space.

Characteristics of dust explosion

Multiple explosions: The first explosion wave will blow up the dust deposited on the equipment or the ground, and in a short time after the explosion, the center area of the explosion will form negative pressure, and the fresh air around will be filled from outside to inside, mixing with the raised dust, resulting in a secondary explosion. In the second explosion, the dust concentration will be higher.

Enterprise dust explosion-proof safety management system

The dust explosion-proof safety management system shall include the following:

(1) dust explosion risk identification, assessment and control;

(2) dust explosion accident potential investigation and treatment;

(3) Safe operating rules for dust work posts;

(4) dust explosion-proof special safety production education and training;

(5) dust cleaning and disposal;

(6) dust removal system and related safety facilities and equipment operation, maintenance, overhaul, repair management;

(7) Emergency handling and rescue of dust explosion accidents.

Criteria for Determining Potential Hazards of Major Accidents in Industrial and Trade Enterprises

11th there is a dust explosion risk of industrial and trade enterprises have one of the following circumstances, should be judged as a major accident potential:

(1) The dust explosion danger place is set in a multi-storey building (structure) of non-frame structure, or the dust explosion danger place is set in the staff dormitory, conference room, office, lounge and other personnel gathering place;

(2) different types of combustible dust, combustible dust and combustible gas and other media that can easily aggravate the risk of explosion share a set of dust removal system, or different buildings (structures), different fire zones share a set of dust removal system, dust removal system interconnection;

(3) The dry dust removal system does not take any of the explosion prevention and control measures such as blasting, inerting, explosion suppression;

(4) Aluminum magnesium and other metal dust dust removal system adopts positive pressure dust removal method, or other combustible dust dust removal system adopts positive pressure blowing dust, without taking measures to prevent ignition source such as spark detection and elimination;

(5) The dust removal system adopts gravity settling chamber dust removal, or adopts dry roadway structure as dust removal air duct;

(6) The dry dust removal system of metal dust such as aluminum and magnesium and wood dust is not equipped with an air lock ash discharge device;

(7) Dust collectors, dust collection bin, etc. are divided into 20 zones of dust explosion danger places where electrical equipment does not meet the explosion-proof requirements;

(8) Before the process equipment such as crushing, grinding, granulation, which is easy to produce mechanical ignition source, no debris removal device is set up, such as iron and stone, or the air pipe connected to the wood product processing enterprise and the sander is not set up spark detection and elimination device;

(9) In case of wet spontaneous combustion of metal dust collection, stacking, storage places do not take ventilation measures to prevent hydrogen accumulation, or dry collection, stacking, storage places do not take waterproof, moisture-proof measures;

(10) Failure to implement the dust cleaning system, resulting in serious dust accumulation on the work site.

Dust explosion-proof safety basic management

1. Risk identification and control

Identify the existing dust explosion dangerous places, determine the dust explosion risk and the number, location, scope and number of operators of dust explosion dangerous places, assess the dust explosion risk level, and develop effective risk control measures.

2, improve the system documents

Improve the dust explosion-proof safety management responsibility system, and clarify the safety management responsibilities of enterprise leaders, safety management personnel and personnel related to explosive dust operations; The establishment of dust explosion-proof related safety management production (including dust removal system management, etc.) and post operating procedures, safety operating procedures should contain the prevention of dust explosion safety operation and emergency disposal measures.

3. Carry out regular safety inspections

Develop dust explosion-proof safety inspection lists based on their own processes, equipment, dust explosion characteristics, explosion protection measures and safety management systems, and regularly carry out dust explosion-proof safety inspections. The enterprise should check at least once every quarter, and the workshop should check at least once a month.

4. Strengthen education and training

Carry out dust explosion-proof safety education and training, popularize dust explosion-proof safety knowledge and relevant regulations and standards, so that employees can understand the risk degree and explosion-proof measures of dust explosion dangerous places of the enterprise; The main person in charge of the enterprise, safety management personnel and dust explosion risk positions of the operators and equipment and facilities inspection and maintenance personnel should carry out special dust explosion-proof safety technology training, and pass the exam, before being allowed to work.

5. Strengthen emergency management

Formulate emergency plans for dust explosion accidents, and carry out emergency drills regularly.

6. Strengthen security warnings

Significant safety warning signs should be set up at the entrances, exits, production areas and key hazardous equipment and facilities of dust explosion hazardous places.

7, strengthen the management of hot work

When hot work is required:

✹ shall be approved by the person in charge of production safety management and obtain the fire certificate;

✹ Before hot work, the combustible dust within 10m of the hot work place should be removed and sufficient fire extinguishing equipment should be equipped;

✹ The hot working section shall be effectively separated or cut off from other sections;

✹ After hot operation, the inside and outside of the equipment should be comprehensively inspected to ensure that there is no hot fusion welding slag left behind to prevent dust smoldering;

✹ Dust shall not enter the open flame working area during hot work and during the cooling period after work is completed.

8, strengthen dust cleaning and control

✹ The enterprise shall formulate a dust cleaning system for dust explosion hazardous places, including the cleaning scope, cleaning method, cleaning period, etc.

✹ All areas where dust may be deposited (including powder storage rooms) and all parts of equipment and facilities shall be cleaned in a timely and comprehensive manner;

✹ The cleaning method that does not generate dust shall be adopted. Compressed air shall not be used for scavenging. The dust collected shall be cleaned by negative pressure vacuuming according to regulations.

✹ The process equipment for the production, processing, storage and transportation of combustible dust shall take measures to prevent dust leakage, and the joints, inspection ports, baffle plates and explosion-discharge covers of the process equipment shall be tightly sealed.

9. Strengthen maintenance management

✹ Formulate safety operation system and emergency handling measures for equipment and facilities maintenance, and formulate implementation plan for inspection and approval;

✹ Safety protection measures shall be taken in accordance with the standard regulations during maintenance operations, and cross-operation is prohibited.

10. Strengthen individual protection

✹ Dust explosion hazardous place operators should be in accordance with the provisions of GB/T11651: use individual labor protection equipment, should not wear chemical fiber easy to generate static electricity work clothes;

✹ Where inert gases are used in the process or where toxic gases may be released, respiratory protection devices shall be provided to ensure the safety of workers.

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