Feed (excluding calcium carbonate), flour, flax, sugar production, milk powder, rubber, coal powder, wood flour, polyethylene plastic, sulfur powder, aluminum powder, and others are industries that may generate explosions. 

 

1.Principles of dust explosions

 

Dust can generally be divided into two categories: combustible dust and non-combustible dust. Combustible dust is further divided into ordinary combustible dust and explosive dust. The main differences between them lie in the conditions for explosion, the speed of reaction, and the amount and pressure of gases produced by the explosion. 

There are many combustible dusts that are not explosively dangerous when accumulated; however, when mixed with air and suspended, reaching a specific concentration range, they can undergo intense combustion or explosion due to external energy induction. This is commonly referred to as dust explosion. 

 

2.Conditions for dust explosions

 

Explosive materials must simultaneously meet the following three conditions to explode:

 

(1)Combustible materials exist in the gas at an appropriate 

 

concentration. Combustible       dust can only burn and not explode when encountering a fire source. Explosions only    occur when the concentration of combustible dust in the gas reaches the explosive limits (the lower and upper explosion limits). Below the lower limit and above the upper limit, combustible dust will not cause an explosion when it comes into contact with a fire source. The difference between the upper and lower explosion limits for dust can be several tens of times, and it is difficult to reach the upper limit in concentration.

Dust with a lower limit concentration of 16-65g/m is designated as dust with explosion danger, and combustible dust with a lower limit concentration of 15g/m is designated as the most explosively dangerous dust. The greater the range between the upper and lower explosion limits, the more opportunities there are to form explosive mixtures, and the greater the risk of explosion. The lower the explosion limit, the lower the concentration required to form an explosive mixture, the easier it is to meet the conditions for an explosion.  

 

(2) There is an ample supply of air and oxidizers. 

 

(3) There is an ignition source. 

 

To ignite the aforementioned explosive mixture, a minimum ignition energy is required.

 

Combustible dust that burns when heated in air or oxygen without the action of a flame or spark ignition source is called spontaneous combustion. The dust with the greatest fire danger has a spontaneous ignition temperature below 250°C.

 

Handling the aforementioned explosive fumes requires special measures to ensure safety and efficiency.To ensure the correct implementation of these measures, it is recommended to collaborate with experts in the handling of explosive dust.If you have any questions, please consult Decent Machinery, as we will provide professional advice and solutions.