As early as the middle of19th century, British scientist Paul Burt first discovered that if animals breathe pure oxygen, it will cause poisoning, and so will humans. If people are exposed to pure oxygen with a concentration exceeding 0.05MPa (half atmospheric pressure), it is toxic to all cells. If the inhalation time is too long, "oxygen poisoning" may occur.
The capillary barrier of the lung is destroyed, which leads to pulmonary edema, pulmonary congestion and bleeding, which seriously affects the respiratory function, and then leads to organ hypoxia and damage. In the pure oxygen environment of 0. 1MPa( 1 atmospheric pressure), people can only survive for 24 hours, and pneumonia will occur, which will eventually lead to respiratory failure and suffocation.
People staying in the high-pressure pure oxygen environment of 0.2MPa(2 atmospheres) for several hours to at most 2 hours will cause brain poisoning, disordered life rhythm, mental disorder and memory loss. If 0.3MPa(3 atmospheres) or even higher oxygen is added, people will experience brain cell degeneration and necrosis, convulsion and coma within a few minutes, leading to death.
In addition, excessive oxygen inhalation will also promote life aging. Oxygen entering the human body reacts with oxidase in cells to generate hydrogen peroxide, which in turn becomes lipofuscin.
This lipofuscin is a harmful substance that accelerates cell aging, accumulates in myocardium, ages myocardial cells and reduces heart function. Accumulation on the wall of blood vessels leads to aging and hardening of blood vessels; Accumulate in the liver and weaken liver function; Accumulate in the brain, causing mental decline and memory decline, and people become dementia; Accumulate on the skin and form senile plaques.
Extended data:
Main uses of oxygen:
1. smelting process: blowing high-purity oxygen during steelmaking will have an oxidation reaction with carbon, phosphorus, sulfur and silicon, which not only reduces the carbon content of steel, but also helps to remove impurities such as phosphorus, sulfur and silicon. Moreover, the heat generated in the oxidation process is enough to maintain the temperature required in the steelmaking process, so blowing oxygen not only shortens the smelting time, but also improves the quality of steel.
In blast furnace ironmaking, increasing the oxygen concentration in blast furnace can reduce the coke ratio and increase the output. In nonferrous metal smelting, oxygen enrichment can also shorten smelting time and increase output.
2. Chemical industry: In the production of synthetic ammonia, oxygen is mainly used for the oxidation of raw gas, so as to strengthen the process and increase the yield of chemical fertilizer. Another example is pyrolysis of heavy oil and gasification of pulverized coal.
3. National defense industry: Liquid oxygen is the best combustion improver for modern rockets, and it is also the oxidant needed in supersonic aircraft. Combustible substances are highly explosive after being impregnated with liquid oxygen, which can be used to make liquid oxygen explosives.
4. Medical treatment: respiratory supply: used in anoxic, hypoxic or anaerobic environments, such as diving, mountaineering, high-altitude flight, space navigation, medical rescue, etc.
5. Other aspects: As combustion improver, it can be used together with combustible gases such as acetylene and propane to achieve the effect of welding and cutting metals. Widely used in all walks of life, especially in machinery enterprises, cutting is also very convenient. This is the preferred cutting method.
According to Article 25 of the Measures for the Safety Management of Gas Cylinders in Xining City, the following provisions shall be observed when using gas cylinders:
(a) the correct use of gas cylinders in accordance with the relevant safety regulations;
(2) Do not weld the gas cylinder, and do not change the steel seal or color code of the gas cylinder;
(three) shall not use expired, scrapped and other unqualified cylinders;
(4) Do not dispose of the residual liquid in the bottle at will;
(five) the use of bottled liquefied petroleum gas in restaurants, entertainment and other public gathering places must comply with the design code for urban gas.
(6) Other provisions of laws and regulations.
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