What are Nitrogen Generators?
A nitrogen generator is a device that uses air as a raw material to physically separate oxygen and nitrogen to obtain nitrogen. According to the different classification methods, namely cryogenic air separation method, molecular sieve air separation method (PSA) and membrane air separation method, industrially applied nitrogen generators can be divided into three types.
Nitrogen generator
- A nitrogen generator is a device that uses air as a raw material to physically separate oxygen and nitrogen to obtain nitrogen. According to the different classification methods, namely cryogenic air separation method, molecular sieve air separation method (PSA) and membrane air separation method, industrially applied nitrogen generators can be divided into three types.
- Nitrogen generator is a nitrogen production equipment designed and manufactured according to pressure swing adsorption technology. The nitrogen generator uses high-quality imported carbon molecular sieve (CMS) as
- Principle of PSA PSA Nitrogen Production
- Carbon molecular sieves can simultaneously adsorb oxygen and nitrogen in the air, and their adsorption capacity also increases with the increase of pressure, and there is no significant difference in the equilibrium adsorption capacity of oxygen and nitrogen at the same pressure. Therefore, it is difficult to complete the effective separation of oxygen and nitrogen only by the change of pressure. If the adsorption rate is further considered, the adsorption characteristics of oxygen and nitrogen can be effectively distinguished. The diameter of oxygen molecules is smaller than that of nitrogen molecules, so the diffusion rate is hundreds of times faster than that of nitrogen. Therefore, the carbon molecular sieve adsorbs oxygen quickly, and it can reach 90% or more in about 1 minute. At this time, the nitrogen adsorption amount is only 5% Left and right, so most of the adsorption at this time is oxygen, and the rest is mostly nitrogen. In this way, if the adsorption time is controlled within 1 minute, the oxygen and nitrogen can be separated initially, that is, the adsorption and desorption are achieved by the pressure difference, which is adsorbed when the pressure is increased, and desorbed when the pressure is decreased. The difference between the adsorption speed of oxygen and nitrogen is achieved by controlling the adsorption time. The time is controlled to be short, the oxygen is fully adsorbed, and the nitrogen has time to adsorb, and the adsorption process is stopped. Therefore, pressure swing adsorption nitrogen production requires pressure change, and the time should be controlled within 1 minute.
- Principle of cryogenic air separation nitrogen production
- Cryogenic Separation of Nitrogen
- Cryogenic nitrogen separation is a traditional method of nitrogen production, which has been used for decades. It uses air as a raw material, which is compressed and purified, and then heat exchange is used to liquefy the air into liquid air. Liquid air is mainly a mixture of liquid oxygen and liquid nitrogen.
- (1) Convenient and fast nitrogen production:
- Advanced technology, unique airflow distributor, make the airflow more uniform, use carbon molecular sieve efficiently, and provide qualified nitrogen in about 20 minutes.
- (2) Easy to use:
- The equipment has a compact structure and is skid-mounted as a whole. It requires a small amount of land and requires no capital investment.
- (3) More economical than other nitrogen supply methods:
- The PSA process is a simple nitrogen production method that uses air as a raw material and consumes only energy consumed by the air compressor. It has the advantages of low operating costs, low energy consumption, and high efficiency.
- (4) Mechatronics design for automatic operation:
- Imported PLC controls fully automatic operation, nitrogen flow pressure and pressure purity can be adjusted and continuously displayed, which can realize unattended operation.
- (5) Wide application range:
- Protective gas for metal heat treatment process, nitrogen gas purification for chemical industry production gas and various storage tanks and pipes, gas for rubber and plastic products production, oxygen fresh-keeping packaging for food industry, purifying and covering gas for beverage industry, and charging for pharmaceutical industry Nitrogen-filled and oxygen-exhausted nitrogen packaging and containers, protective gas for electronic components and semiconductor production processes in the electronics industry. Purity, flow and pressure are stable and adjustable to meet the needs of different customers.
- Technical indicators:
- Flow: 5-1000Nm3 / h
- Purity: 95% -99.9995%
- Dew point: -40 ° C
- Pressure: 0.8Mpa adjustable
- The special nitrogen generator for the oil and gas industry is suitable for the fields of nitrogen protection, transportation, coverage, replacement, emergency repair, maintenance, nitrogen injection and oil recovery in the petroleum and natural gas extraction in the mainland, coastal and deep-sea oil and gas extraction. It has the characteristics of high safety, strong adaptability and continuous production.
- Special nitrogen generators for the chemical industry are suitable for petrochemical, coal chemical, salt chemical, natural gas chemical, fine chemical, new materials, and their extended chemical product processing industries. Nitrogen is mainly used for covering, purging, replacing, cleaning, and pressure delivery. , Chemical reaction agitation, chemical fiber production protection, nitrogen filling protection and other fields.
- The special nitrogen generator for the metallurgical industry is suitable for heat treatment, bright annealing, protective heating, powder metallurgy, copper and aluminum processing, magnetic material sintering, precious metal processing, bearing production and other fields. It has the characteristics of high purity, continuous production, and some processes require nitrogen to contain a certain amount of hydrogen to increase brightness and so on.
- The special nitrogen generator for the coal mine industry is suitable for the fields of fire prevention and fire extinguishing, gas and gas dilution in coal mining. It has three specifications: fixed ground, mobile ground, and mobile underground, which fully meet the nitrogen requirements under different working conditions.
- Nitrogen making machine for rubber tire industry is suitable for nitrogen protection and molding in the vulcanization process of rubber and tire production. Especially in the production of all-steel radial tires, the new process of nitrogen vulcanization has gradually replaced the steam vulcanization process. It has the characteristics of high nitrogen purity, continuous production, and high nitrogen pressure.
- Food industry special nitrogen generator is suitable for green storage of food, nitrogen-filled packaging of food, fresh-keeping of vegetables, sealing (canning) of wine and preservation, etc.
- Explosion-proof nitrogen generator is suitable for places with explosion-proof requirements for equipment such as chemical industry, petroleum and natural gas.
- The special nitrogen generator for the pharmaceutical industry is mainly used in the fields of pharmaceutical production, storage, packaging, packaging and so on.
- The special nitrogen generator for the electronics industry is suitable for semiconductor production packaging, electronic component production, LED, LCD liquid crystal display, lithium battery production and other fields. The nitrogen generator has the characteristics of high purity, small size, low noise, low energy consumption and so on.
- The container type nitrogen generator is suitable for petroleum, natural gas, chemical industry and other related fields. It has the characteristics of strong adaptability and mobile operation.
- The vehicle-mounted mobile nitrogen-making vehicle is suitable for the fields of mining, pipeline purging, replacement, emergency rescue, flammable gas, and liquid dilution in the oil and gas industry. It is divided into low-pressure, medium-pressure, and high-pressure series. Homework and other characteristics.
- Nitrogen flushing machine for automobile tires is mainly used for nitrogen flushing of automobile tires in automobile 4S shops and automobile repair shops, which can prolong the service life of tires and reduce noise and fuel consumption.
- Mass is the weight of the gas, often expressed in milligrams (mg), grams (g), kilograms (kg), tons (t). Volume refers to the volume of the container in which the gas is located. Often expressed in cubic millimeters (mm3), cubic centimeters (cm3), cubic meters (m3). Specific volume is the volume occupied by a unit weight of substance, represented by the symbol V, gas specific volume units are expressed in m3 / kg, and liquid specific volume is expressed in l / kg.
- Pressure, pressure, atmospheric pressure, absolute pressure, relative pressure
- The force generated when gas molecules move against the container wall is called pressure. The pressure per unit area of the container is called pressure. The unit of pressure is customary to use millimeters of mercury (mmHg) / square centimeter (cm2), internationally accepted (legal measurement) Pa (Pa), kilopascal (kPa), megapascal (MPa). After conversion, 1mmHg = 133.3Pa = 0.1333kPa, 1MPa = 1000kPa = 1000000Pao1ATA = 0.1MPao.
- The pressure on the earth's surface or surface objects caused by a very thick atmosphere surrounding the earth's surface is called "atmospheric pressure" with the symbol B; the pressure directly acting on the surface of a container or object is called "absolute pressure". Starting with absolute vacuum, the symbol is PABS.
- The pressure measured with pressure gauges, vacuum gauges, U-tubes and other instruments is called "gauge pressure" (also called relative pressure). "Gage pressure" starts from atmospheric pressure and the symbol is Pg. The relationship between the three is: PABS == B + Pg.
- Temperature, absolute temperature, relative temperature, critical temperature, critical pressure
- Temperature is a statistical average of the thermal motion of a substance's molecules. Gas temperature is generated by the thermal movement of gas molecules. The unit of gas temperature is usually expressed in Celsius (° C), and the temperature at which water freezes is 0 ° C. The absolute temperature is often used in physics, and it is expressed by "K". The absolute temperature is -273 ° C as zero. The relationship between Celsius and absolute temperature is T = t + 273. In addition, British scientists often use "Fahrenheit", the symbol is oF.
- Because any gas can be liquefied at a certain temperature and pressure. The higher the temperature, the higher the pressure required for liquefaction. However, when the temperature exceeds a certain value, it cannot be liquefied even if the pressure is increased. This temperature is called the critical temperature. The lowest pressure at this temperature is called the critical pressure.
- It refers to the temperature at which the water in the gas becomes saturated water vapor. When unsaturated water vapor becomes saturated water vapor, extremely fine dew drops appear. The temperature at which dew drops appear is called "dew point". Dew point is related to pressure, so there is a distinction between atmospheric dew point (normal pressure dew point) and dew point under pressure. Atmospheric dew point refers to the condensation temperature of water at atmospheric pressure, and dew point under pressure refers to the condensation temperature of water at that pressure. There is a conversion relationship between the two (see the conversion table). For example, the pressure dew point at pressure 0.7Mpa is 5 , the corresponding atmospheric pressure (0.101Mpa) dew point is -20 . In the gas industry, unless otherwise specified, the dew points referred to are all atmospheric dew points. Vaporization refers to the process of changing a substance from a liquid to a gas, which includes evaporation and boiling. Condensation is the process by which a gas becomes a liquid.
- purity
- Purity is an important technical parameter of a gas. Taking nitrogen as an example, according to the purity of the national standard nitrogen, it is divided into three grades of industrial nitrogen, pure nitrogen and high purity nitrogen. Their purity is 99.5% (O2 less than or equal to 0.5%), 99.99% (O2 less than or equal to 0.01%), and 99.999% (O2 is 0.001% or less).
- Flow, volume flow, mass flow
- Flow refers to the amount of gas that passes through any cross section per unit time during the flow of gas. There are two ways to express flow, namely volume flow and mass flow. The former refers to the volume of gas passing through any section of the pipeline, and the latter is the mass of the gas passing through. In the gas industry, volumetric flow is generally measured in m3 / h (or L / H). Because the volume of gas is related to temperature, pressure and humidity, in order to facilitate comparison, the so-called volume flow refers to the standard state (temperature is 20 ° C, pressure is 0.101MPa, and relative humidity is 65%). At this time, the flow rate is in Nm3 / h is the unit, "N" means standard state.
- Air is compressible. The compressed air is called compressed air when the air compressor does mechanical work to reduce its volume. Compressed air contains many impurities: 1. Water, including water mist, water vapor, and condensed water; 2. Oil: including oil pollution, oil vapor; 3. Various solid substances such as rust mud, metal powder, rubber powder, tar particles And the fines of filter materials, sealing materials, etc .; In addition, there are a variety of harmful chemical odor substances. Compressed air can be removed by pressurization, cooling, adsorption and other methods. Liquid water can be removed by methods such as heating, filtration, and mechanical separation. Adsorption, membrane penetration
- Adsorption is the selective concentration of one or more components in a gas on the surface of a porous solid. The component to be adsorbed is called an adsorption medium, and the porous solid is called an adsorbent. The connecting force between the adsorbent and the adsorption medium is a chemical bond, and the analysis of the adsorption medium depends on increasing the temperature or reducing the partial pressure of the component in the air pressure. The other case is that the chemical reaction between the adsorbed component and the solid adsorbent is called chemical adsorption, and chemical adsorption cannot be regenerated in general.
- Membrane permeation refers to the selective permeation of polymer by gas from one side of the membrane to the other based on one or more gas components during gas purification. The component dissolves on the surface of the polymer film and transmits a concentration difference along the film. The concentration difference is maintained because the partial pressure of the component on one side of the film is higher than the partial pressure of the component on the other side of the film.
- Common legal unit of measurement for gases
- Prepared in accordance with the "Order on Uniform Implementation of Legal Units of Measurement in China" issued by the State Council on February 27, 1984
- Legal unit of measure: SI unit
- Legal unit of measure: Units other than the International System of Units
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