Why does dust explode?
According to the leaders of the Work Safety Supervision Bureau, the dust explosion is caused by the high pressure formed by the combustion of combustible dust suspended in the air. Dust explosion itself is a special kind of combustion phenomenon, which requires three conditions: combustible material, combustion-supporting material and ignition source.
According to experts, there are currently seven types of dust known to be explosive: metals (such as magnesium powder, aluminum powder); coal; grain (such as wheat, starch); feed (such as blood meal, fish meal); agricultural and sideline products (such as cotton, tobacco): Forest products (such as paper powder, wood powder); synthetic materials (such as plastics, dyes). Dust fire and explosion accidents mostly occur in coal mines, flour mills, sugar mills, textile mills, sulfur mills, feed, plastics, metal processing plants, and grain depots.
Behind the dust explosion is the lack of “safety awareness”
In fact, the explosion temperature of dust such as flour or feed is equivalent to the ignition temperature of a piece of flammable paper. A little spark may cause a dust explosion. And the power of dust explosion is huge-because it is easy to produce a second explosion. The first explosion air wave will blow up the dust deposited on the equipment or the ground. In a short time after the explosion, negative pressure will be formed in the central area of the explosion, and the surrounding fresh air will fill in from the outside to the inside. The dust mixes, causing a second explosion. In the second explosion, the dust concentration will be higher.
But in fact, the tragedy of dust explosion is completely avoidable. Experts pointed out that the State Administration of Work Safety has long issued corresponding regulations, of which the “GB15577–2007 Dust Explosion Safety Regulations” is the most widely used. According to the regulations, the factory must strictly implement the dust explosion-proof standards in both design and construction. If an enterprise can do a good job in the four aspects of the production equipment itself, the production environment, the elimination of static electricity, and the prevention of secondary explosions, it should be able to prevent tragedies from happening.
How to prevent dust explosion
The enterprise should determine whether there is combustible dust in the enterprise, and where there may be an explosive dust environment. The second is to take measures to eliminate dust sources.
One is to use suitable and effective dust removal facilities to control the dust in the plant, such as the use of enclosed equipment, ventilation and dust removal, ventilation and dust removal or wetting and dust reduction measures. It should be noted that electric dust removal equipment cannot be used for combustible dust, and wet dust removal equipment cannot be used for metal dust. The fan of the dust removal equipment should be installed on the clean air side. In order to prevent dust from flying, the dust removal equipment should be opened first when the equipment is started, and then the main engine should be turned on. When it is shut down, the opposite is true.
The second is to take measures to prevent dust accumulation in the design of the plant. For example, all parts of the dust workshop should be smooth, and beams, brackets, walls and equipment should have a surface structure that is easy to clean. In addition, doing a good job of cleaning in the workshop and timely manual cleaning is also a good way to eliminate dust sources.
The third is to take measures to eliminate ignition sources. During the production process, measures should be taken to prevent open flames, equipment or devices in direct contact with dust (such as light sources, heating sources, etc.) from possible hot surfaces, lightning or static electricity, frictional impact and other factors from igniting the dust.
The fourth is to take measures to reduce the content of combustion-supporting gas. The usual method is to add inert gas (such as nitrogen) to the mixture of dust and combustion-supporting gas to reduce the oxygen content, so that the combustible dust cannot form an explosive mixture.
The fifth is to eliminate relatively closed spaces. Set up process equipment with dust explosion hazard in an open area outside the building, and set up process equipment with dust explosion hazard in the factory building at a higher position in the building and close to the outer wall.
In addition, enterprises should earnestly do a good job in safety production and dust explosion education, popularize dust explosion knowledge and safety regulations, so that employees understand the degree of danger and explosion protection measures in the company’s dust explosion hazardous locations; employees in dangerous positions should be equipped with special safety techniques and measures. Professional training, after passing the examination, they will be allowed to work.
Feed factory shoulder the responsibility of safe production
In the opinion of experts, to ensure the implementation of these preventive measures, the key is to implement the main responsibility of the company’s production safety, otherwise these specific measures are just empty words.
In 2010, the State Council issued the “Notice on Further Strengthening the Work Safety of Enterprises”, which made more specific, clear and strict regulations on strengthening the implementation of the main responsibility of enterprise safety in production and comprehensively improving the level of safety in production.
Experts pointed out that, judging from some safety production accidents in recent years, some enterprises have blindly pursued economic benefits, emphasized production and ignored safety, and have weak safety management when the economy is recovering. Some companies produce illegally without a license or with incomplete licenses, and produce in violation of laws and regulations with super-capacity, super-strength, and over-capacity. The safety supervision responsibilities of some localities and departments are not implemented, and the measures are not in place. In the final analysis, the main responsibility of the company’s production safety has not been implemented.
Experts believe that a tragic accident has warned us that enterprises are the main body, internal cause and foundation of safe production. Only when government supervision and social supervision are implemented in the production management of enterprises can they eliminate the hidden dangers of safe production to the greatest extent. In place, the safety production situation cannot continue to improve. Therefore, in order to prevent the occurrence of serious and serious accidents in production safety, it is necessary to firmly grasp the main body of responsibility of the enterprise, and effectively improve the safety production guarantee of the enterprise by strengthening safety management, increasing safety investment, strengthening technical equipment, strict safety supervision, and serious accountability ability. “It must be seen that only when the production environment is safe can the production and operation of the enterprise continue normally, and it is possible to continue to create value and profits.”
