09,22,2026 10 views
Small dust, big hidden danger. Despite the insignificant size of dust particles, the explosive power caused by dust is enormous! Compared with gas explosions, dust explosions have the characteristics of releasing greater energy, stronger destructive power, and continuous multiple explosions, and are extremely difficult to extinguish. Therefore, it is particularly important to take preventive measures!
Industrial production is the main cause of dust generation. When dust reaches a sufficient concentration within a certain range and encounters a fire source, it can cause an explosion with unimaginable consequences. In order to avoid such problems, reasonable and feasible explosion-proof measures must be taken to improve the safety of dust explosion hazardous areas and prevent the occurrence of dust explosions.
To prevent dust explosions, the first thing to know is how dust explosions occur. Dust combustion will only trigger an explosion under certain conditions, including:
Firstly, it must be combustible dust;
Secondly, there should be sufficient oxygen content (air or oxygen);
Thirdly, combustible dust is thoroughly mixed with air or oxygen to form dispersed dust;
Fourthly, the dust content reaches the explosive concentration;
Fifth: There exists an ignition source with the minimum energy required to ignite combustible dust.
In addition, dust explosions also have certain requirements for spatial range, air pressure, and temperature. In other words, if the above conditions cannot be met, the dust will not explode. So we have a direction for preventing dust explosions.
So how to prevent dust explosions?Similar to the combustion process, the three basic conditions for dust explosion must be met simultaneously, namely the formation of a certain concentration of dust, the presence of a certain concentration of oxygen or other combustion supporting gases, and a certain intensity of ignition source, in order for dust explosion to occur. If any of these basic conditions can be eliminated or avoided, the occurrence of dust explosions can be prevented.
1、 Prevent from combustible materials
In actual industrial production, there are several measures to control the concentration of dust in the air, including:
1. The equipment, containers, and conveying systems used to handle dust should have good sealing performance to prevent dust leakage from the equipment as much as possible.
2. Eliminate or control the diffusion range of dust and reduce the concentration of combustible dust.
For example, separate equipment that is prone to producing dust and install specialized protective covers, local exhaust hoods, or consider dust collection devices; The dust movement system should be operated under negative pressure as much as possible to reduce or eliminate dust leakage; Install effective ventilation and dust removal systems, strengthen ventilation and exhaust for dust removal.
3. Prevent dust deposition and clean up dust in a timely manner to avoid secondary explosions.
For example, the floor, walls, and ceiling of the dust workshop are required to be smooth and free of bumps and depressions; Do a good job of cleaning, timely use explosion-proof vacuum dust collection equipment for manual cleaning, and wet the dust in the dust workshop with spray water if conditions permit; Raising the relative humidity of the air to over 65% can promote dust settling and absorb a large amount of heat generated by dust oxidation, while reducing static electricity; Ensure proper ventilation and promptly remove dust from the workshop.
In addition, the fan of the dust removal equipment should be installed on the clean air side. Attention should be paid to the use of electrostatic precipitators for flammable dust and wet dust collectors for metal dust. When starting the equipment, the dust removal device should be turned on first, and then the main engine should be turned on; When shutting down, the opposite is true to prevent dust from flying.
2、 Prevent from the perspective of combustion aids
The preventive measures in this regard mainly adopt inert gas protection to reduce the oxygen content in the system. Inert gases commonly used in industry include N2, CO2, etc.
3、 Prevent from ignition sources
In places where dust is generated, targeted ignition source prevention must be carried out according to the specific operating environment. Specific measures include:
When repairing equipment with dust, attention should be paid to selecting the correct tools and tools that generate impact or friction sparks during maintenance should not be used.
2. Electrical equipment in the venue should meet explosion-proof requirements, and mechanical equipment that is prone to static electricity and sparks should be installed as little as possible, and static grounding protection measures should be taken. The crushed material must undergo strict screening, stone removal, and iron absorption treatment to prevent impurities from entering the crusher and generating sparks.
3. When conducting welding operations in dust explosion hazardous areas, the materials inside the equipment should be cleaned first, and effective measures should be taken to prevent welding slag from falling into the equipment or materials.
4. Dust deposited on hot surfaces such as lighting fixtures and mechanical equipment should be cleaned up in a timely manner to prevent it from overheating for too long and causing spontaneous combustion.
5. Any place where combustible dust is generated should be designated as a no fire zone, and the use of open flames should be strictly controlled.
6. The surface of heating devices, high-temperature material conveying pipelines, etc. must not exceed the ignition temperature of the dust cloud under any circumstances.
7. Regularly inspect electrical equipment to prevent ignition sources caused by aging or short circuits in its wiring.
In conditional processing workshops, spark detection systems and fire extinguishing linkage systems can be installed. These systems are usually installed on dust removal pipelines or powder conveying pipelines. After detecting sparks in the pipeline, appropriate water mist is used to extinguish the sparks.
