Reaction history of gas mixture explosion

The explosion of gas mixture has two different processes: thermal reaction and chain reaction

(1) Thermal reaction mechanism

Combustion and explosion of gas mixture are essentially the same from the point of view of chemical reaction

(2) Chain reaction mechanism

Some explosion phenomena cannot be explained by the thermal reaction mechanism

According to the chain reaction theory, after explosive mixtures (such as flammable explosive gases and oxygen) are in contact with external energy (such as fire sources), the activated molecules will absorb energy and dissociate into free radicals, that is, free radicals.

There are two types of chain reactions: straight-chain reactions and branched-chain reactions

1.

The linear reaction means that each free radical undergoes its own chain reaction.

2.

Branched chain reaction means that one free radical can generate more than one new free radical in the reaction.

In the case that chain growth means that the reaction can proliferate free radicals, if the reaction rate of destroying free radicals (chain termination) at the same time is not high, the number of free radicals will increase, and the number of reaction chains will also increase.

Figure 13-1 Branched chain reaction

The chain reaction process is roughly divided into three stages: ① chain initiation, free radical generation; ② chain transfer, the free radical acts on other compounds involved in the reaction to generate new free radicals; ③ chain termination, that is, the consumption of free radicals, so that The chain reaction ended