The principle and work flow of nitrogen making machine, application description Pressure swing adsorption nitrogen making machine is designed and manufactured according to pressure swing adsorption technology nitrogen generating equipment. Two adsorption towers are usually used in parallel, and the automatic control system strictly controls the timing according to a specific programmable program, alternately performs pressure adsorption and decompression regeneration, completes nitrogen and oxygen separation, and obtains the required high purity nitrogen.

Working principle of pressure swing adsorption nitrogen making machine

PSA pressure swing adsorption nitrogen production principle

Carbon molecular sieve can absorb oxygen and nitrogen in the air at the same time, and its adsorption capacity also increases with the increase of pressure, and there is no significant difference in the equilibrium adsorption capacity of oxygen and nitrogen under the same pressure. Therefore, it is difficult to effectively separate oxygen and nitrogen by pressure changes alone. If the adsorption rate is further considered, the adsorption properties 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 nitrogen, so the adsorption speed of carbon molecular sieve oxygen is also very fast, adsorption about 1 minute to reach more than 90%; At this time, the adsorption of nitrogen is only about 5%, so the adsorption is mostly oxygen, and the rest is mostly nitrogen. In this way, if the adsorption time is controlled within 1 minute, oxygen and nitrogen can be initially separated, that is, adsorption and desorption are achieved by pressure difference, adsorption when the pressure rises, desorption when the pressure falls. The difference between oxygen and nitrogen depends on the difference in the speed of adsorption between the two, which is achieved by controlling the adsorption time, the time is controlled very short, oxygen has been fully adsorbed, and nitrogen has not had time to adsorb, and the adsorption process has stopped. Therefore, pressure swing adsorption nitrogen production must have pressure changes, but also to control the time within 1 minute.

Nitrogen machine action

Using air as raw material, l uses physical methods to separate oxygen and nitrogen in it.

There are three kinds in industry, namely cryogenic air separation method, molecular sieve air separation method (PSA) and membrane air separation method.

Species introduction



Cryogenic air separation for nitrogen production



Nitrogen production by cryogenic air separation is a traditional method of nitrogen production, which has a history of recent decades. It takes air as raw material, after compression, purification, and then heat exchange to liquefy the air into liquid air. Liquid-air is mainly a mixture of liquid oxygen and liquid nitrogen, using the boiling point of liquid oxygen and liquid nitrogen is different (at 1 atmospheric pressure, the boiling point of the former is -183 ° C, the latter is -196 ° C), through the distillation of liquid-air, so that they are separated to obtain nitrogen. The cryogenic air separation nitrogen equipment is complex, occupies a large area, has high infrastructure costs, more one-time investment in equipment, higher operating costs, slow gas production (12 ~ 24h), high installation requirements and long cycle. Comprehensive equipment, installation and infrastructure factors, equipment below 3500Nm3/h, PSA equipment of the same specification is 20% to 50% lower than cryogenic air separation equipment. The cryogenic air separation nitrogen device is suitable for large-scale industrial nitrogen production, while the medium and small-scale nitrogen production is uneconomical.

Nitrogen production by air separation of molecular sieve



With air as raw material, carbon molecular sieve as adsorbent, the use of pressure swing adsorption principle, the use of carbon molecular sieve on oxygen and nitrogen selective adsorption and nitrogen separation method, commonly known as PSA nitrogen production. This method is a new nitrogen production technology developed rapidly in the 1970s. Compared with the traditional nitrogen production method, it has the advantages of simple process, high degree of automation, fast gas production (15 ~ 30 minutes), low energy consumption, product purity can be adjusted according to the needs of users in a large range, easy operation and maintenance, low operating cost, and strong adaptability of the device, so it is very competitive in the nitrogen production machine equipment below 1000Nm3/h. More and more popular with small and medium nitrogen users, PSA nitrogen has become the preferred method for small and medium nitrogen users.

Membrane air separation for nitrogen production



Using air as raw material, under certain pressure conditions, oxygen and nitrogen gas with different properties in the membrane have different penetration rates to separate oxygen and nitrogen. Compared with other nitrogen production equipment, it has the advantages of simpler structure, smaller volume, no switching valve, less maintenance, faster gas production (≤3 minutes), convenient capacity increase, etc. It is especially suitable for medium and small nitrogen users with nitrogen purity ≤98%, and has the best functional price ratio. When the nitrogen purity is more than 98%, its price is more than 15% higher than that of the PSA nitrogen maker of the same specification

Edit this section nitrogen machine industry related parameters



Mass is the weight of the gas, often expressed in milligrams (mg), grams (g), kilograms (kg), and tons (t). Volume refers to the volume of the container in which the gas resides. Often expressed in cubic millimeters (mm3), cubic centimeters (cm3), and cubic meters (m3). The specific volume is the volume occupied by the unit weight of the substance, expressed by the symbol V, the specific volume of the gas is expressed by m3/kg, and the specific volume of the liquid is expressed by l/kg.

Pressure, pressure, atmospheric pressure, absolute pressure, relative pressure

The force produced by the movement of gas molecules against the walls of the container is called pressure. The pressure exerted on the unit area of the container is called pressure. The unit of pressure is customary to use millimeters of mercury (mmHg)/ square centimeter (cm2), international common (legal measurement) Pa (Pa), kPa (kPa), MPa (MPa). After conversion, 1mmHg=133.3Pa=0.1333kPa, 1MPa=1000kPa=1000000Pao1ATA=0.1MPao.

The pressure caused by a very thick layer of atmosphere surrounding the earth's surface on the earth's surface or surface objects is called "atmospheric pressure", symbol B; The pressure directly acting on the surface of the container or object is called "absolute pressure", and the absolute pressure value takes the absolute vacuum as the starting point, and the symbol is PABS.

The pressure measured by the pressure gauge, vacuum gauge, U-tube and other instruments is called "table pressure" (also called relative pressure), "table pressure" takes the atmospheric pressure as the starting point, and the symbol is Pg. The relation among the three is: PABS==B+Pg.

Temperature, absolute temperature, relative temperature, critical temperature, critical pressure

Temperature is the statistical average of the thermal motion of the molecules of a substance. Gas temperature is caused by the thermal motion of gas molecules. The unit of gas temperature is commonly expressed in Celsius (° C), and the temperature of water freezing is 0 ° C. In physics, absolute temperature is often used, denoted by "K". The absolute temperature is -273 ° C as zero. The relation between Celsius and absolute temperature is T=t+273. In addition, British scientists often use the word "Fahrenheit", with the symbol oF.

Because any gas can be liquefied at a point of temperature and pressure, the higher the temperature, the higher the pressure required for liquefaction, but when the temperature exceeds a certain value, even how much pressure can not be liquefied, this temperature is called the critical temperature, at this temperature the lowest pressure is called the critical pressure.

Refers to the temperature at which the water in the gas changes from unsaturated water vapor to saturated water vapor, when the unsaturated water vapor becomes saturated water vapor, there is a very fine dew, and the temperature when the dew appears is called the "dew point". Dew point is related to pressure, so there is an atmospheric dew point (atmospheric dew point) and a dew point under pressure. Atmospheric pressure dew point refers to the condensation temperature of the water under atmospheric pressure, and the dew point under pressure refers to the water condensation temperature under the pressure, and there is a conversion relationship between the two (see the conversion table), such as the pressure of 0.7Mpa when the pressure dew point is 5℃, the corresponding atmospheric pressure (0.101Mpa) dew point is -20℃. In the gas industry, unless otherwise specified, the dew point referred to is the atmospheric pressure dew point. Vaporization refers to the process by which a substance changes from a liquid to a gas, including evaporation and boiling. Condensation is the process by which a gas becomes a liquid.

purity

Purity is an important technical parameter of gas. Nitrogen, for example, according to the purity of the national standard nitrogen machine is divided into industrial nitrogen, pure nitrogen and high purity nitrogen three levels, their purity is 99.5%(O2 less than or equal to 0.5%), 99.99%(O2 less than or equal to 0.01%) and 99.99%(O2 less than or equal to 0.001%).

Flow, volume flow, mass flow

Flow rate refers to the amount of gas passing through any section in unit time during the gas flow process. There are two ways to express flow, namely volume flow and mass flow. The former refers to the volume of gas through any section of the pipeline, the latter is the mass of gas through, and the volume flow is generally used in the gas industry to m3/h(or L/H) as a unit of measurement. Because the volume of the gas is related to temperature, pressure and humidity, in order to facilitate comparison, the volume flow rate usually referred to is the standard state (temperature is 20℃, pressure is 0.101Mpa, relative humidity is 65%), the flow rate at this time is Nm3/h as a unit, 'N' is the standard state.

Air has compressibility, and the air after the air compressor does mechanical work to reduce its volume and increase its pressure is called compressed air. Compressed air contains many impurities: 1. Water, including water mist, steam, condensate; 2. Oil: including oil, oil vapor; 3. Various solid substances such as: rust mud, metal powder, rubber powder, tar particles and filter materials, sealing materials, etc.; In addition, there are a variety of harmful chemical odor substances. Compressed air can be pressurized, cooled, adsorption and other methods to remove water vapor. The liquid water can be removed by heating, filtration, mechanical separation and other methods. Adsorption, membrane penetration

Adsorption is the selective concentration of one or more components in the gas on the surface of the porous solid, the adsorbed component is called the adsorption medium, and the porous solid is called the adsorbent. The connection between the adsorbent and the adsorption medium is a chemical bond, and the resolution of the adsorption medium depends on heating up or reducing the partial pressure of the component in the air pressure. Another situation is the chemical reaction of the adsorption component with the solid adsorbent, which is called chemical adsorption, and chemical adsorption can not be regenerated under normal circumstances.

Membrane penetration refers to the process of gas purification in which the polymer separates the gas based on the selective penetration of one or more gas components from one side of the membrane to the other. The component dissolves on the surface of the polymer film and is transferred along the film to form a concentration difference maintained by the partial pressure of the component on one side of the film being higher than that of the component on the other side of the film.

The use of pressure swing adsorption nitrogen machine system in various industries



The special nitrogen machine for oil and gas industry is suitable for nitrogen protection, transportation, coverage, replacement, rescue, maintenance, nitrogen injection and other fields in continental oil and gas exploitation, coastal and deep-sea oil and gas exploitation. It has the characteristics of high safety, strong adaptability and continuous production.

Chemical industry special nitrogen machine is suitable for petrochemical, coal chemical, salt chemical, natural gas chemical, fine chemical, new materials and its extension chemical product processing industry, nitrogen is mainly used for covering, purging, replacement, cleaning, pressure transport, chemical reaction agitation, chemical fiber production protection, nitrogen filling protection and other fields.

It 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 the brightness.

Coal mine industry special special nitrogen machine is suitable for coal mining fire extinguishing, gas and gas dilution fields, with ground fixed, ground mobile, underground mobile three specifications, fully meet the different working conditions of nitrogen demand.

Rubber tire industry special nitrogen machine is suitable for rubber and tire production vulcanization process of nitrogen protection, molding and other fields. 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 machine is suitable for food green storage, food nitrogen packaging, vegetable preservation, wine sealing (can) filling and preservation.

The explosion-proof nitrogen machine is suitable for chemical industry, oil and natural gas and other places where the equipment has explosion-proof requirements.

Pharmaceutical industry special nitrogen machine is mainly used in drug production, storage, packaging, packaging and other fields.

The electronic industry special nitrogen machine is suitable for semiconductor production packaging, electronic components production, LED, LCD liquid crystal display, lithium battery production and other fields. The nitrogen making machine has the characteristics of high purity, small size, low noise and low energy consumption.

The container type nitrogen machine is suitable for oil, natural gas, chemical industry and other related fields, that is, it has the characteristics of strong adaptability and mobile operation.

The mobile nitrogen making vehicle is suitable for the oil and gas industry mining, pipeline purging, replacement, emergency rescue, flammable gas, liquid dilution and other fields, divided into low pressure, medium pressure, high pressure series, with strong mobility, mobile operation and other characteristics.

Car tire flush nitrogen nitrogen machine, mainly used in car 4S shop, car repair factory car tire flush nitrogen, can extend tire life, reduce noise and fuel consumption.