Sprinkling flour on a flame will explode. Why? How powerful is the dust explosion?

Flour plays a very important role in our daily life. It can be made into many delicious foods, such as jiaozi and noodles. It is an indispensable kitchen material for most families, but many people may not know that flour also hides fatal dangers. If you are in a confined space, the situation will be even worse. Scientists use a blower to blow flour, remotely start the electronic igniter, and the acrylic box explodes instantly. Moreover, even if it is not in a confined space, when the flour particles reach a certain concentration, it will explode when it meets an open flame.

On May 2nd, 1878, washburne, the largest flour mill in the world, was in full swing in Minneapolis, Minnesota. Suddenly, the factory exploded and a mushroom cloud rose from the ground. Twenty-two people died and five factories were completely destroyed. The main component of flour is starch, which is a carbohydrate composed of sugar molecules and is very easy to burn. Flour particles are very small, each cubic meter of air contains about 50 grams of flour dust, which will burn immediately when it meets an open flame.

Sprinkling flour on a flame will explode. Why? To make matters worse, when a grain of flour burns, it will transfer heat and flame radiation to nearby suspended or blown dust, which will also burn when heated and evaporated. The reaction speed is gradually accelerated, and finally an explosion is formed by violent combustion, which will produce a lot of toxic gases in severe cases. This continuous and intense combustion phenomenon is also called dust explosion.

Flour explosion only needs to meet four conditions: the concentration of combustible dust such as flour is appropriate; Dust suspension; A certain oxygen content; The temperature reaches the lowest ignition point of the material. So be sure not to pour flour into the kitchen with an open flame. In addition, scientists have done experiments. When the fermented flour meets the flame, the flame immediately jumps upward. The researchers used starch and coffee powder instead of flour, and the result was the same. Experiments show that when we turn on the gas stove, don't sprinkle any powder!