according to the explosion of substances in the explosion process changes, can be divided into chemical explosions, physical explosions and nuclear explosions.

a physical explosion

Substance due to changes in the state of the pressure caused by sudden changes in the formation of the explosion is called a physical explosion. Physical explosion is characterized by the chemical composition of the material before and after are not changed.

such as steam boilers due to rapid vaporization of water, container pressure increases dramatically, the pressure exceeds the strength of the equipment can withstand the explosion; compressed gas or liquefied petroleum gas cylinders, oil drums heat explosion. Physical explosion itself does not carry out the combustion reaction, but it produces the impact of the fire can be caused directly or indirectly.

Two, chemical explosion

Chemical explosion refers to the rapid oxidation or decomposition of substances due to temperature, pressure increase or both increase and the formation of explosive phenomena. Chemical explosion before and after the chemical composition and properties of substances have undergone fundamental changes.

This explosion is fast, the explosion produced a large amount of heat and a lot of gas pressure, and issued a loud sound. Chemical explosions can directly cause fire, has a great fire hazard. The explosion of various explosives and gas, liquid vapors and dust mixed with air formed after the explosion are chemical explosions, especially the latter explosion exists in almost all areas of industry, transportation, life, etc., the danger is very great, should pay special attention to.

three, nuclear explosion

nuclear explosion (nuclear explosion) nuclear weapons or nuclear devices in a few microseconds of the instantaneous release of a large amount of energy process. In order to facilitate comparison with ordinary explosives, the explosive power of nuclear weapons, that is, the energy released by the explosion, with the release of considerable energy of TNT explosive weight, known as TNT equivalent. The energy released by the nuclear reaction can make the reaction zone (also known as the active zone) medium temperature rises to tens of millions of open, the pressure increased to billions of atmospheric pressure (1 atm equal to 101325 Pa), become a high temperature and high pressure plasma.