1. Use of nitrogen
Nitrogen is a colorless, non-toxic, odorless inert gas. Therefore, gas nitrogen has been widely used as a protective gas. Liquid nitrogen has been widely used as a freezing medium that can be in contact with air. It is a very important gas. , some typical uses are as follows:
1. Metal processing: nitrogen source for heat treatments such as bright quenching, bright annealing, nitriding, nitrocarburizing, soft carbonization, etc.; protective gas during welding and powder metallurgy sintering processes, etc.
2. Chemical synthesis: Nitrogen is mainly used to synthesize ammonia. The reaction formula is N2+3H2=2NH3 (the conditions are high pressure, high temperature, and catalyst. The reaction is a reversible reaction) or synthetic fiber (nylon, acrylic), synthetic resin, synthetic rubber, etc. important raw materials. Nitrogen is a nutrient that can also be used to make fertilizers. For example: ammonium bicarbonate NH4HCO3, ammonium chloride NH4Cl, ammonium nitrate NH4NO3, etc.
3. Electronics industry: Nitrogen source for processing large-scale integrated circuits, color TV picture tubes, television and radio components and semiconductor components.
4. Metallurgical industry: protective gas for continuous casting, continuous rolling and steel annealing; combined nitrogen blowing at the top and bottom of converter for steelmaking, sealing for converter steelmaking, sealing for blast furnace top, gas for pulverized coal injection for blast furnace ironmaking, etc.
5. Food preservation: nitrogen-filled storage and preservation of grains, fruits, vegetables, etc.; nitrogen-filled preservation packaging of meat, cheese, mustard, tea and coffee, etc.; nitrogen-filled and oxygen-depleted preservation of fruit juices, raw oils and jams, etc.; various Bottle-like wine purification and coverage, etc.
6. Pharmaceutical industry: Nitrogen-filled storage and preservation of traditional Chinese medicine (such as ginseng); Nitrogen-filled injections of Western medicine; Nitrogen-filled storage and containers; Gas source for pneumatic transportation of medicines, etc.
7. Chemical industry: protective gas in replacement, cleaning, sealing, leak detection, dry coke quenching; gas used in catalyst regeneration, petroleum fractionation, chemical fiber production, etc.
8. Fertilizer industry: nitrogen fertilizer raw materials; gas for replacement, sealing, washing, and catalyst protection.
9. Plastic industry: pneumatic transmission of plastic particles; anti-oxidation in plastic production and storage, etc.
Nitrogen Production Manufacturers - China Nitrogen Production Factory & Suppliers (xinfatools.com)
10. Rubber industry: rubber packaging and storage; tire production, etc.
11. Glass industry: protective gas in the production process of float glass.
12. Petroleum industry: nitrogen charging and purification of storage, containers, catalytic cracking towers, pipelines, etc.; air pressure leak testing of pipeline systems, etc.
13. Offshore oil development; gas covering of platforms in offshore oil extraction, pressure injection of nitrogen for oil extraction, inerting of storage tanks, containers, etc.
14. Warehousing: To prevent flammable materials in cellars and warehouses from catching fire and exploding, fill them with nitrogen.
15. Maritime transportation: gas used for tanker cleaning and protection.
16. Aerospace technology: rocket fuel booster, launch pad replacement gas and safety protection gas, astronaut control gas, space simulation room, cleaning gas for aircraft fuel pipelines, etc.
17. Application in the oil, gas, and coal mining industries: Filling the oil well with nitrogen can not only increase the pressure in the well and increase oil production, but the nitrogen can also be used as a cushion in the measurement of drill pipes, completely avoiding the mud pressure in the well. Possibility of crushing the lower tube column. In addition, nitrogen is also used in downhole operations such as acidification, fracturing, hydraulic blowholes, and hydraulic packer setting. Filling natural gas with nitrogen can reduce the calorific value. When replacing pipelines with crude oil, liquid nitrogen can be used to burn and inject materials at both ends to solidify and seal them.
18. Others:
A. Paints and coatings are filled with nitrogen and oxygen to prevent the polymerization of oil drying; oil and natural gas storage tanks, containers, and transportation pipelines are filled with nitrogen and oxygen, etc.
B. Car tires
(1) Improve tire driving stability and comfort
Nitrogen is an almost inert diatomic gas with extremely inactive chemical properties. The gas molecules are larger than oxygen molecules, are not prone to thermal expansion and contraction, and have a small deformation range. Its penetration rate into the tire sidewall is about 30 to 40% slower than that of air, and it can maintain Stabilize tire pressure, improve tire driving stability, and ensure driving comfort; nitrogen has low audio conductivity, equivalent to 1/5 of ordinary air. Using nitrogen can effectively reduce tire noise and improve driving quietness.
(2) Prevent tire blowout and running out of air
Flat tires are the number one cause of road traffic accidents. According to statistics, 46% of traffic accidents on highways are caused by tire failure, of which tire blowouts account for 70% of total tire accidents. When the car is driving, the tire temperature will rise due to friction with the ground. Especially when driving at high speed and emergency braking, the temperature of the gas in the tire will rise rapidly and the tire pressure will increase sharply, so there is a possibility of tire blowout. High temperatures cause the tire rubber to age, reduce fatigue strength, and cause severe tread wear, which is also an important factor in possible tire blowouts. Compared with ordinary high-pressure air, high-purity nitrogen is oxygen-free and contains almost no water or oil. It has low thermal expansion coefficient, low thermal conductivity, slow temperature rise, which reduces the speed of tire heat accumulation, and is non-flammable and does not support combustion. , so the chance of a tire blowout can be greatly reduced.
(3) Extend tire service life
After using nitrogen, the tire pressure is stable and the volume change is small, which greatly reduces the possibility of irregular tire friction, such as crown wear, tire shoulder wear, and eccentric wear, and increases the service life of the tire; the aging of rubber is affected by oxygen molecules in the air Due to oxidation, its strength and elasticity decrease after aging, and there will be cracks. This is one of the reasons for shortening the service life of tires. The nitrogen separation device can eliminate oxygen, sulfur, oil, water and other impurities in the air to the greatest extent, effectively reducing the oxidation degree of the tire inner lining and rubber corrosion, and will not corrode the metal rim, extending the tire life. The service life also greatly reduces the rust of the rim.
(4) Reduce fuel consumption and protect the environment
Insufficient tire pressure and increased rolling resistance after heating will cause an increase in fuel consumption when driving. Nitrogen, in addition to maintaining stable tire pressure and delaying tire pressure reduction, is dry, contains no oil or water, and has low thermal conductivity. , the slow heating feature reduces the temperature rise when the tire is running, and the tire deformation is small, the grip is improved, etc., and the rolling resistance is reduced, thereby achieving the purpose of reducing fuel consumption.
2. Application of liquid nitrogen freezing
1. Cryogenic medicine: surgery, cryogenic treatment, blood refrigeration, drug freezing and cryogenic crushing, etc.
2. Bioengineering: cryopreservation and transportation of precious plants, plant cells, genetic germplasm, etc.
3. Metal processing: freezing treatment of metal, frozen cast bending, extrusion and grinding, etc.
4. Food processing: quick freezing equipment, food freezing and transportation, etc.
5. Aerospace technology: launch devices, cold sources of space simulation rooms, etc.
3. With the advancement of science and technology and the development of economic construction, the application range of nitrogen has become increasingly widespread, and has penetrated into many industrial sectors and daily life areas.
1. Application in metal heat treatment: Nitrogen-based atmosphere heat treatment with nitrogen odor as the basic component is a new technology and process for energy saving, safety, non-pollution of the environment and full utilization of natural resources. It has been shown that almost all heat treatment processes, including quenching, annealing, carburizing, carbonitriding, soft nitriding and recarburization, can be completed using a nitrogen-based gas atmosphere. The quality of the metal parts treated can be comparable to that of Comparable to traditional endothermic atmosphere treatments. In recent years, the development, research and application of this new process at home and abroad are in the ascendant and have achieved fruitful results.
2. Application in the electronics industry: In the production process of electronic components and semiconductor components, nitrogen with a purity of more than 99.999% needs to be used as a protective gas. At present, my country has used high-purity nitrogen as carrier gas and protective gas in the production processes of color TV picture tubes, large-scale integrated circuits, liquid crystals and semiconductor silicon wafers.
3. Application in chemical fiber production process: High-purity nitrogen is often used as a protective gas in chemical fiber production to prevent chemical fiber products from being oxidized during production and affecting the color. The higher the purity of nitrogen, the more beautiful the color of chemical fiber products. Nowadays, some new chemical fiber factories in my country are equipped with high-purity nitrogen devices.
4. Application in residential storage and preservation: At present, the method of sealing warehouses, filling with nitrogen and removing air has been widely used in foreign countries to store grains. Our country has also successfully tested this method and entered the stage of practical promotion and application. Using nitrogen exhaust to store grains such as rice, wheat, barley, corn, and rice can prevent insects, heat, and mildew, so that they can be kept in good quality through the summer. This method is to seal the grain tightly with plastic cloth, first evacuate it to a low vacuum state, and then fill it with nitrogen with a purity of about 98% until the internal and external pressures are balanced. This can deprive the grain pile of oxygen, reduce the respiration intensity of the grain, and inhibit the reproduction of microorganisms. All borers will die due to lack of oxygen within 36 hours. This method of reducing oxygen and killing insects not only saves a lot of money (about one percent of the cost of fumigation with highly toxic drugs such as zinc phosphide), but also maintains the freshness and nutritional value of food and prevents bacterial infection. and drug contamination.
Nitrogen-filled storage and preservation of fruits, vegetables, tea, etc. is also the most advanced method. This method can slow down the metabolism of fruits, vegetables, leaves, etc. in a high-nitrogen and low-oxygen environment, as if entering a state of hibernation, inhibiting after-ripening, and thus keeping them fresh for a long time. According to tests, apples stored with nitrogen are still crispy and delicious after 8 months, and the preservation cost of apples per kilogram is about 1 dime. Nitrogen-filled storage can greatly reduce the loss of fruits during the peak season, ensure the supply of fruits in the off-season market, improve the quality of exported fruits, and increase foreign exchange income.
Tea is vacuumed and nitrogen-filled, that is, the tea is placed into a double-layered aluminum-platinum (or nylon polyethylene-aluminum composite foil) bag, the air is extracted, nitrogen is injected, and the bag is sealed. After one year, the tea quality will be fresh, the tea soup will be clear and bright, and the taste will be pure and fragrant. Obviously, using this method to preserve fresh tea is much better than vacuum packaging or freezing packaging.
At present, many foods are still packaged in vacuum or frozen packaging. Vacuum packaging is prone to air leakage, and frozen packaging is prone to deterioration. None of them are as good as vacuum nitrogen-filled packaging.
5. Application in aerospace technology
The universe is cold, dark and in a high vacuum. When humans go to heaven, they must first conduct space simulation experiments on the ground. Liquid nitrogen and liquid helium must be used to simulate space. Large-scale space simulation chambers in the United States consume 300,000 cubic meters of nitrogen gas per month to conduct large-scale wind tunnel simulation tests. On the rocket, in order to ensure the safe operation of the flammable and explosive liquid hydrogen device, nitrogen fire extinguishers are installed at appropriate locations. High-pressure nitrogen is also the pressure supply gas for rocket fuel (liquid hydrogen-liquid oxygen) and the cleaning gas for the combustion pipeline.
Before an aircraft takes off or after landing, in order to ensure safety and prevent the risk of explosion in the engine combustion chamber, it is usually necessary to clean the engine combustion chamber with nitrogen.
In addition, nitrogen is also used as a protective gas in atomic reactors.
In short, nitrogen is increasingly favored in terms of protection and insurance. The demand for nitrogen is growing with the development and emphasis of industry. With the rapid development of my country's economic construction, the amount of nitrogen used in my country will also increase rapidly.
Post time: Feb-22-2024
