Compressed gas and liquefied gas (1)

Gas refers to a substance that is completely gaseous at a standard pressure of 101.

Under normal circumstances, gaseous gases are not easy to store, ship, and use, and are not easy to exchange as commodities.

1.

Compressed gas and liquefied gas refer to compressed, liquefied or pressurized dissolved gas, and should meet one of the following two conditions:

(1) Compressed or liquefied gas with a critical temperature lower than 50°C and a vapor pressure greater than 294kPa

(2) At 21.

2.

(1) Compressed gas

Compressed gas refers to the gas that is completely gaseous in the storage at 20°C

(2) Liquefied gas

Liquefied gas refers to the gas that is completely liquid in the storage at 20°C, and refers to the gas state under normal pressure that changes to the liquid state after being compressed by pressure

(3) Dissolved gas

Dissolved gas refers to the gas compressed and dissolved in the solvent in the storage, such as acetylene gas dissolved in acetone

(4) Frozen liquefied gas

Frozen liquefied gas refers to the gas that is partially in the liquid state in the storage at low temperature.

Three, nature classification

According to the physical and chemical properties and hazards of the gas, the gas is generally divided into three categories: flammable gas, non-combustible non-toxic gas and toxic gas

(1) Flammable gas

Flammable gas refers to the gas whose lower explosion limit is less than 13% (volume fraction) at 20℃ and standard pressure of 101.

(2) Non-combustible and non-toxic gas

Refers to non-toxic non-flammable gas at 20 ℃, not lower than the vapor pressure of 280kPa or frozen liquid transport noncombustible toxic gases, such as nitrogen, argon, carbon dioxide , oxygen, combustion-supporting gas, such as compressed air

(3) Toxic gas

It refers to a toxic gas inhalation lethal dose the LC ₅₀ <5000mL / m ^³ gases, such as chlorine, carbon monoxide , ammonia, sulfur dioxide , hydrogen sulfide and the like