Oil-free (dry) rotary vane vacuum pumps are positive displacement pumps that allow obtaining a vacuum of medium depth in the complete absence of oil exhaust in the exhaust air. The depth of the vacuum achieved is from 90 to 400 mBar of residual pressure, depending on the model. Which is from 9 to 40% of atmospheric pressure.

It is quite difficult to create a good oil-free rotary vane pump, so the number of manufacturers in the world is not so large. They are mainly made in Europe (, and). And only low-capacity pumps are produced in the USA, China and Taiwan. Among the latter, Taiwanese pumps are in greatest demand.

Operating principle

Dry rotary vane pumps have generally the same principle of operation as. They also use an eccentrically mounted rotor with blades that can slide freely in their slots.
Animation 1: Operating principle of a rotary vane pump

However, there are some differences. Dry pumps do not use oil to seal the gap between the blades and the housing, nor to lubricate moving parts, nor for cooling. Therefore, the blades of dry pumps are made not of metal, but of graphite composite. Graphite creates much less friction compared to metal, so it does not require much cooling. In addition, graphite blades quickly grind into the surface on which they slide, providing good sealing of the gaps between the body and the blades.

On the one hand, the design of oil-free pumps is simpler: there is no oil separator and oil channels. On the other hand, the lack of lubrication increases the requirements for the quality of surface treatment.

Pros and cons of oil-free rotary vane vacuum pumps (compared to oil ones)

There are two main reasons why you should choose a dry rotary vane pump: relatively clean air at the outlet and the ability to work with rough vacuum for a long time. In addition, there is no need to constantly monitor the oil level and worry about drying the pumped gas.

All the advantages of dry pumps are a mirror image of the disadvantages of oil-lubricated models: if it is preferable for oil to operate in a deep vacuum mode, then a dry pump can operate for a long time with a rough vacuum at the inlet. A situation also often arises when the pumped-out air remains in the same room where people work. Having passed through an oil-lubricated model, the air is inevitably saturated with oil vapors, which not only smell unpleasant, but are also not particularly useful for others. Exhaust line filters solve this problem to some extent. But there are no perfect filters.

On the other hand, passing through an oil-free rotary pump, although the air does not remain perfectly clean, in this case, instead of oil, graphite dust particles enter the air. Firstly, this dust is released much less than oil. And secondly, graphite does not smell, and it is much easier to filter it. Therefore, an oil-free pump is a good choice for areas where people work.

Another significant disadvantage of oil-lubricated pumps is the need to constantly monitor the oil level. This level can either increase due to the appearance of condensation, or decrease, for example, when working with a rough vacuum or when the temperature is exceeded. Any of these scenarios is detrimental to a vane oil pump: if there is not enough oil, it will overheat and burn out, and if there is a lot of condensation in the oil, the pump will quickly rust. An oil-free pump is initially devoid of these disadvantages: there is no need to constantly monitor it; it is enough to check the thickness of the blades once every 2-3 thousand working hours.

In general, for residual pressures above 400 mbar, the oil-free pump is good choice. But it is no longer suitable for creating a deeper vacuum. The most advanced models from our catalog can provide only 100 mBar of residual pressure. Another limitation is service life. Oil-filled models can provide the same performance for years (only occasionally adding oil is required), which is what many laboratories use, maintaining a stable vacuum in the laboratory cabinet day and night. A dry rotary vane pump can also operate 24/7, but as the blades wear out, its performance will drop. Therefore, it is recommended to turn on such a pump exactly when it is needed and turn it off at the end of the shift.

Wear of working plates

As you can see from the animation above, the working plates are constantly moving along special slots in the rotor. Flying out under the influence of centrifugal force, they fit tightly to the walls of the chamber and divide the free space of the working chamber into several isolated volumes.

The pump rotor rotates at high speed (usually 1400-1500 rpm, since 4-pole electric motors are used), so the problem of friction of the plates against the inner surface of the working chamber arises. In oil-lubricated pumps, this problem is not acute, so the working plates (blades) can be either composite or more durable metal. However, in dry pumps the vanes can only be made of graphite composite (carbon vanes). Graphite itself is a good lubricant - graphite plates slide across the working chamber without overheating. But at the same time, graphite wears out relatively quickly. Moreover, not only its length is reduced due to friction against the pump body, but also its thickness due to friction against the rotor is reduced.

Image 1. Three types of wear on graphite blades of rotary vane pumps.

Wear of graphite blades (plates) leads to air leaks and a decrease in vacuum depth, as well as pump performance. What average term oil-free pump blade services? Most manufacturers bashfully do not indicate this period. However, we do have some information.

Taiwanese Stairs Vacuum indicate the need to replace blades after 8,000 - 10,000 hours. However, they note that the performance of any oil-free rotary vane pumps begins to decline after 3,000 hours of operation.

The Italians DVP write about the service life of records of 10,000 hours. An engineer once came to our office who was working on an SB 16 pump from this Italian company. He said that the pump worked for them for 20,000 hours (though in compressor mode, but this does not change the essence), after which it stopped working normally (we were talking about wear on the blades, and not about pump failure). At the same time, the exhaust hoses inside became covered thin layer graphite dust. This example says that the manufacturer indicates the minimum guaranteed service life of the blades; in practice, they can work longer, but with a decrease in operating parameters.

The Germans Becker series VX, KVX are record holders for the service life of blades (alas, and for the price of pumps too) - at least 20,000 hours, in practice from 20 to 40 thousand.

Image 2. Graph of performance decline of dry rotary vane pumps due to blade wear.

At what vacuum depth does the efficiency of rotary vane vacuum pumps become greatest?

The efficiency of oil-free vane pumps is not a fixed value, but depends on the operating point (vacuum depth). At an inlet pressure close to atmospheric (rough vacuum), the pump efficiency is very low and becomes acceptable (40% and above) at a vacuum depth of 300 mBar (700 mBar residual pressure). The efficiency reaches its maximum (almost 60%) at a vacuum of 600-700 mbar (300-400 mbar absolute pressure), and then begins to decrease again to 40% as the vacuum deepens.

Image 3. Comparison of the efficiency of a dry rotary vane vacuum pump and a single-stage vortex blower.

If we compare, for example, an oil-free rotary vane vacuum pump and a single-stage vortex blower operating in vacuum mode, it turns out that these 2 devices do not compete with each other, but complement each other. In the range of generated pressures from -100 to -300 mbar, the vortex blower shows best values Efficiency, and in the range from -300 to -900 mBar, the vane-rotor device works much more efficiently.

Extremely reliable and efficient dry, claw and screw type vacuum pumps are widely used in general industrial processes, as well as for creating vacuum in explosive and corrosive environments.

World leader in the design and production of dry vacuum pumps is the English company Edwards. Edwards is a pioneer in the field of dry gas pumping. With over 90 years of experience using vacuum pumps in a variety of operating conditions, including processes with high dust and contaminant content, and over 150,000 dry vacuum pumps delivered worldwide, we provide the most sophisticated solution to dry vacuum applications.

Dry pumping technology provides significant reductions in operating costs, increased productivity, improved product quality, and the creation of more favorable conditions labor in work areas. This technology guarantees high levels reliability in situations where oil sealed pumps are at the edge of their operating range. “Dry” pumps are capable of pumping out media with the highest permissible water vapor pressure at the pump inlet, several times higher than the highest water vapor pressure for pumps with an oil seal, and they do this in the complete absence of any contamination. This capability makes the pumps ideal for vacuum pumping in drying processes and other industrial applications.

Patented by Edwards in 1984, the Drystar claw-type dry vacuum technology was an innovation in the world of vacuum and continues to enjoy well-deserved popularity around the world to this day.

Thus, the first models of Edwards pumps with a claw mechanism, the Drystar brand, were the GV series pumps, now installed all over the world in a wide variety of general industrial processes, in metallurgy, in drying processes, surface treatment, and the production of semiconductor devices. The principle of operation of GV pumps is based on a claw gripping mechanism, and the additional Roots stage used in the design of the pumps allows increasing pumping speed in the operating range and achieving maximum operating speed.

The experience gained during the development of dry claw pumps was used in the EDP series pumps, the main difference of which from the GV series pumps is the vertical direction of the flow of the pumped medium, due to which, if liquids enter the working volume, they immediately flow out of the pump without affecting it. At the same time high temperature, maintained inside the pump, avoids condensation of media, including chemically active ones, and, as a result, the influence of corrosion. Thanks to this feature, the EDP series pumps optimally meet high demands. technological processes chemical and pharmaceutical industries.

In parallel with the technology of dry pumping with a claw gripping mechanism, the technology of vacuuming with screw pump rotors was being developed.

The IDX Series Progressive Progressive Pumps are ideal for processes that require high performance under vacuum or rapid pumping from atmospheric pressure. The pumps use a unique double-sided symmetrical screw mechanism, which simplifies the compensation system thermal expansion shafts This design, which has no analogues in products from other manufacturers, allows you to easily pump gas media with a high dust content. It is important to note that the pump can be used as a foreline pump in a multi-stage vacuum system. Systems based on IDX pumps are a standard solution in steel evacuation processes.

Subsequently, by analogy with the advent of “chemical” versions of GV-EDP pumps, the CDX screw pump was developed, which is a modification of the IDX pump, but has a number of features that allow it to be used in chemical and petrochemical production conditions.

In combination with booster pumps EH/HV/SN, dry vacuum pumps of the GV, EDP, IDX series can achieve a capacity of up to 120,000 m 3 /h. As a special case, IDX-based systems for metallurgy, which are ready-made solutions for ladle-furnace systems of 50, 100 and 150 tons (vacuum degassing VD and vacuum decarburization VOD processes). Pumping speed can be varied by adding additional stages, allowing vacuum systems to be designed to meet the needs of a specific process.

Currently, a new generation of vacuum pumps for general industrial processes - the GXS screw type pump - has become actively widespread. This pump is a completely ready-to-use solution, the pump is ready for use immediately after delivery. It is equipped with a control panel located directly on the case, and also has a number of additional options that allow you to configure a system that fully meets the needs of a specific customer. The wide range of GXS pumps can be presented either in a single-stage pump form factor or in combination with a booster pump (in a single housing), which allows for performance from 160 to 3,500 m 3 /h.

Currently, Edwards remains closely focused on vacuum processes in the chemical and pharmaceutical industries. Thus, based on the GXS, the CXS series pumps were developed. The main difference between this pump and the GXS is that all elements of the pump’s electronic control system are placed in a separate explosion-proof unit.

You can find out more about the capabilities and characteristics of Edwards dry vacuum pumps in the relevant sections of our catalog.

Innovative development of the manufacturer Edwards - EDS series pumps for complex technological processes in the chemical, petrochemical and pharmaceutical industries

In various fields human activity a vacuum is required. This term characterizes the state of the gas phase, the pressure of which is below atmospheric. It is measured in millimeters mercury or pascals. Rarefaction of gases occurs when a substance is forcibly removed from devices with a limited volume. A technical device designed for these purposes is called a vacuum pump. It can be used on its own or included in more complex systems.

Vacuum is widely used in various technical devices. It allows you to reduce the boiling point for water or chemical liquids, remove gases from materials that require increased homogeneity of composition, and create sterile processing and storage conditions. With small dimensions and economical energy consumption, modern vacuum pumps allow you to quickly achieve a deep degree of vacuum. They are used in a wide variety of processes and fields of activity:

• in the oil refining and chemical industries to maintain necessary conditions the course of reactions and separation of the resulting mixtures;
• when degassing metals and other materials to create parts with a uniform structure and absence of pores;
• in the pharmaceutical and textile industries for quick drying of products without increasing the temperature;
• V food industry when packaging milk, juices, meat and fish products;
• in the process of vacuuming refrigeration and other equipment with increased requirements for the absence of moisture;
• for the normal functioning of automatic conveyor lines using vacuum suction cups as grippers;
• when equipping production and research laboratories;
• in medicine during the operation of breathing apparatus and dental offices;
• in printing for fixing thermal films.

Operating principle of vacuum pumps

A vacuum is created by mechanically removing a substance from a confined space. Technically this is possible in various ways. Operating principle jet vacuum pump based on the entrainment of gas molecules by a stream of water or steam escaping from high speed from the ejector nozzle. Its design involves connecting a side pipe in which a vacuum is created.

The advantage of this design is the absence of moving parts, but the disadvantage is the mixing of substances and low efficiency.

In technology, the most widely used mechanical units. The operation of a vacuum pump with a rotating or reciprocating main part consists of periodically creating an expanding space inside the housing, filling it with gas from the inlet pipe, and then pushing it out through the outlet. Structural device The design of the vacuum pump can be very diverse.

Main types of vacuum pumps

In the manufacture of devices for creating vacuum, metal and plastic materials are used that are resistant to the chemical effects of the pumped medium and have sufficient mechanical strength. Much attention is paid to the accuracy of the fitting of the units and the tightness of the contact of the surfaces, eliminating the reverse leakage of gases. Here is a list of the main types of vacuum pumps, differing in design and principle of operation.

Water ring

A liquid ring vacuum pump is one of the options for liquid ring units, using to create a vacuum circulation clean water . It has the appearance of a cylinder with a rotor equipped with blades, rotating on an off-center shaft. Before starting work, it is filled with liquid.

When the engine starts, the impeller accelerates water along the inner walls of the housing. A crescent-shaped vacuum region is formed between it and the rotor. Gas flows into it from the pump inlet pipe. Moving blades move it along the shaft and throw it out through the outlet. Units of this type are often used for partial gas purification due to its intense contact with water.

Using liquid as a working body provides many advantages.

1. Water rotating in the space between the rotor and the pump body eliminates the possibility of backflow of gases, replacing seals and reducing the requirements for precision manufacturing of parts.
2. All rotating parts of the pump are constantly flushed with liquid, which reduces friction and improves heat removal.
3. Such devices rarely require repairs, have a long service life and consume minimal electricity.
4. Working with gases containing drops of water and small mechanical impurities does not have any effect negative influence on technical condition equipment.

The latter circumstance is important when using such pumps for pumping air from containers containing moisture. They are used for air conditioners and other refrigeration units when evacuating the system before filling them with freon.

Vane rotor

Such pumps have a cylindrical body with a carefully polished inner surface and a rotor located inside it. Their axes do not coincide, so the side gap has different sizes. The rotor includes special movable plates, which are pressed against the body by springs and divide the free space into sectors of variable volume. When the engine is turned on, the gases begin to move so that a vacuum is always created in the intake pipe, and excess pressure is always created in the pressure pipe.

To reduce friction, the plates are made of antifriction materials or use special low-viscosity oils. Pumps of this type are capable of creating a fairly strong vacuum, but they are sensitive to the purity of the liquid or gas being pumped, require regular cleaning and contaminate the product with traces of lubricant.

Diaphragm-piston

The working body of pumps of this operating principle is flexible membrane associated with the lever mechanism. It is made from modern composite materials that are resistant to mechanical loads. Its edges are firmly attached to the body, and the central part bends under the action of an electric or pneumatic drive, alternately reducing and increasing the space of the internal chamber.

The change in volume is accompanied by the suction and expulsion of incoming gases or liquids. When two membranes work together in antiphase, a continuous pumping mode is ensured. The valve system regulates the correct distribution and direction of flows. The mechanism does not have rotating or rubbing parts in contact with the pumped product.

TO advantages of such pumps should include:

• no contamination of the product with grease or mechanical impurities;
• complete tightness, eliminating leaks;
• high efficiency;
• ease of flow control;
• long-term operation in dry mode, which does not harm the structure;
• the ability to use a pneumatic drive for work in explosive environments.

Screw

The operating principle of screw pumps is based on displacement of liquid or gas along a rotating screw. They consist of a drive, one or two helical-shaped rotors and a correspondingly shaped stator. High precision manufacturing of parts does not allow the pumped medium to slip back. As a result, excess pressure is formed at the pump outlet, and vacuum is formed at the inlet.

Due to the high requirements for manufacturing quality, such equipment is not cheap. It cannot be kept in “dry” mode for a long time.

The main advantages of such pumps:

• uniformity of flow;
• low noise level;
• ability to pump liquids with mechanical inclusions.

Vortex

Vortex vacuum pumps by their design resemble centrifugal equipment. They also have an impeller with blades that rotates on a central shaft. The fundamental difference is the location of the inlet pipe on the outer circumference of the housing, and not in the area of ​​the central axis.

The minimum gap between the impeller and the housing ensures stable movement of the pumped liquid in the required direction. Units of this type are capable of creating a fairly high discharge pressure and have a self-priming effect. These pumps are easy to operate, easy to repair and have proven themselves in pumping gas-liquid mixtures, but they have low efficiency. They are sensitive to the ingress of mechanical impurities, which can lead to rapid wear of the impeller.

Making your own vacuum pump

If you are not ready to bear the cost of purchasing factory equipment, try making a vacuum pump yourself. It may be suitable for pumping air out of a small volume container. medical syringe or a slightly retrofitted bicycle hand pump.

Advice! For frequent use and evacuation of large vessels, it is more convenient to use electrically driven devices.

Let's consider the option of manufacturing a vacuum installation from the compressor of an old refrigerator. It is already designed for pumping gas and with minimal repairs will be able to create a vacuum. Your actions will be extremely simple:

• at some distance from the compressor, cut two copper tubes, approaching him;
• dismantle the compressor along with the power supply circuit or replace it together with the starting relay with a new one by analogy with the old one;
• put a durite hose of a suitable diameter on the copper pipe that came from the condenser and connect it at the other end to a vacuum container;
• to make the connection tight, you can use a standard clamp or use twisted steel wire;
• connect the vacuum pump to the electrical network and, after starting, check the air outlet from the second copper pipe to ensure its correct operation.

Important! The refrigerator compressor is not designed to be used in a humid environment, so care must be taken not to allow water to come into contact with it.

Today, quite a lot of physical and chemical processes are carried out in a vacuum environment. To create it, vacuum pumps are used various types and types. They are divided by type of work, technical capabilities, and functional purpose. Today, manufacturers of vacuum equipment produce positive-displacement and non-volume pumps.

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Volumetric mechanical installations pump air through the action of moving working elements. They gradually compress the air as the volume of the chamber decreases. This type of pump includes installations with a diaphragm, vane-rotor, liquid ring, cam and spiral working element. Typically, they are used to create low and medium vacuum, which is 10-2 mm Hg. Art. Some installations are capable of creating high pressure.

Other pumps do not use mechanical principle work in which gases are exposed low temperatures or other phenomena that contribute to the creation of a vacuum. Pumps of this type used to create high and ultra-high vacuum. These include diffusion, vapor-oil, multi-charge, getter, getter-ion and other pumps. However, most of these pumps work in conjunction with foreline pumps to provide the required pressure. They are necessary to create preliminary vacuum and are represented by all types of mechanical pumps.

Domestic vacuum pumps

Domestic vacuum pumps, unlike foreign installations, are large in size, made of high-quality materials, highly efficient, and reliable. They can be used in various industries, as well as in agriculture. Domestic samples of the same series have similar designs, but have many modifications. Most pump elements are suitable for other models, so they have high maintainability.

The most common models produced in our country include the NVR and BBN series units. They are widely used in various systems, but differ significantly in their design. These models have many modifications that differ in size, basic performance indicators, and residual pressure. HBP installations use mineral and semi-synthetic vacuum oils, which are designed to seal gaps. In VVN pumps, additional lubricating elements are not used due to the fact that this function is performed by the working fluid, which is usually represented by water.

Vacuum pumps NVR

NBP vane vacuum pumps are used to create low medium and high vacuum. A wide range of installations allows them to be used in industrial, agricultural, woodworking, food and other enterprises. The installations are distinguished by their ability to create a vacuum with a high residual pressure in a short period of time. HBP pumps are universal because they can perform various types of tasks.

The model range is represented by such units as NVR-0.1D, 2NVR-0.1D, 2NVR-0.1DM, NVR-1, NVR-4.5D, 2NVR-5DM, 2NVR-5DM1, 2NVR-60D, 2NVR-90D , 2NVR-250D. The units can have a single-stage or two-stage type of action, be modified with a gas ballast valve and have different capacities. Installations of this type can carry out efficient pumping only if the vacuum system is completely free of dust, dirt and condensation.

Vacuum pumps VVN

Vacuum pumps model range VVN differ significantly from other pumps in that liquid is used in the system when performing the operation. As a rule, water is used in this capacity. Pumps have a narrower functionality, but are at the same time indispensable in many areas of activity.

The main advantages of liquid ring vacuum pumps VVN:

• capable of purifying the pumped mixture;
• applicable in systems with mechanical contamination;
• environmental cleanliness;
• lack of vacuum oil in the system;
• ease of use and maintenance;
• low power consumption;
• maintainability;

VVN vacuum pumps are used in the food, chemical, medical, pulp and paper, microbiological, agricultural, woodworking, pharmaceutical and perfume industries.

Vacuum pumps for industrial furnaces

In industrial furnaces, vacuum pumps are used to speed up the operations of annealing, normalization, hardening, and also improve the quality of the material. In a vacuum space, all chemical and physical processes are performed quickly and efficiently.

Vacuum pumps can be used in industrial furnaces of arc, induction, thermal, and hydrogen types. Often, to ensure low residual pressure, diffusion furnaces, which have a non-volumetric type of action, are used.

In order to effectively implement heat treatment An industrial furnace must use pumps that provide sufficient pumping speed. This also allows you to count on high performance. No less important indicator is the residual pressure, but it can vary significantly in different furnaces depending on the type of operation being performed.

Vacuum pumps for climate chambers

Climate chambers are equipment that is necessary to study the qualities of various materials and units. To carry out the operation efficiently and quickly, vacuum pumps are used in the installations.

In order to use a pump in a climate chamber, it must:

• withstood elevated/lowered temperatures;
• high humidity;
• created a sufficient level of vacuum;
• had the ability to create and maintain the necessary pressure.

Rotary vane vacuum pumps

Rotary vane pumps are excellent for industrial applications. Wide range models allows you to perform various types of operations. Installations with high residual pressure and speed are used for climatic chambers and heat treatment furnaces.

The installations have high reliability, wear resistance, and maintainability. They can be classified as universal means of creating a vacuum. At the same time, to ensure their operation, it is necessary that the vacuum system be cleaned of mechanical impurities and moisture. To operate in climatic chambers, pumps made of stainless steel are used.

Vacuum pumps for degassing chambers

Degassing is a process that cannot take place without the participation of a vacuum pump. But it performs the main task of pumping gases and gas mixtures from various materials. To pump out gases and vapors from dense materials, as a rule, two-stage vacuum pumps are used.

Two stage vacuum pump

The two-stage vacuum pump is an upgraded model of the single-stage pump with higher performance. This type of installation is widely used in production areas where it is necessary to create higher pressure. At the same time, they are reliable and can be used with various types of gases.

In two-stage vacuum pumps, the chambers are dependent on each other. This helps to synchronize and therefore increase productivity. Every year they become more and more popular due to the fact that they have practically no large dimensions, but at the same time provide the best technical performance.

Dry Vacuum Pump

Dry vacuum pumps are becoming increasingly important because they are capable of pumping out a system without contaminating it. Unlike other installations, they do not use an oil seal.

They have lower performance, unlike analog installations, but are quite reliable. For efficient and proper operation, it is necessary to periodically carry out maintenance by replacing plates that may wear out during operation.

Oil-free vacuum pump

Oil-free vacuum ones are used in enterprises where it is necessary to ensure the cleanliness of the operation. I often use them in laboratory research, where it is necessary to create a sufficient level of residual pressure in a short period of time. The installations are highly reliable and maintainable.

When making this type of pump, designers make careful calculations because it is important that there are sufficient clearances between elements to avoid friction, but not so large as to significantly reduce performance.

High vacuum vacuum pumps

The creation of a high vacuum, as a rule, occurs using several pumps, including a fore-vacuum and a high-vacuum unit. The fore-vacuum pump, represented by one of the volumetric units, performs preliminary discharge, pumping out up to 97% of gases, and the high-vacuum pump performs the rest of the work, reaching the limit values.

The following can be used as high vacuum pumps:

• turbomolecular;
• diffusion;
• ionic;

Turbomolecular pumps

Turbomolecular pumps are significantly inferior to other pumps high pressure. They are capable of independently creating a high vacuum, since they have a mechanical operating principle. The settings operate in the range of 10-2 – 10-8 Pa. The main working mechanism is represented by a stator and a rotor with disks that are located at a certain angle.

Molecules of gas displacement, being in a turbomolecular pump, significantly increase the speed of movement due to collisions with each other. The rotor rotates at a speed that exceeds 10,000 revolutions, which is the main reason for the creation of high pressure.

Vacuum ion pump

Ionic or getter-ion vacuum pumps had widespread before the advent of other high vacuum pumps. With their help, a pressure of 10-6 mbar is created. Today they are used less frequently, but still find their consumers. Pumps of this type are characterized by environmental friendliness and an advantageous method of obtaining ultra-high vacuum.

In the installation, molecules are captured and bound by gases or a getter layer, and then retained within the volume of the installation. They are able to maintain a vacuum even when not in use. The main element of the pump is the chamber and other fixed elements. The ion pump consumes a small amount of electricity and has low noise.

A turbomolecular pump (TMP) is a special pump that allows you to create and maintain a deep vacuum for a long time, on the order of 10 -2 to 10 -8 Pa. The etymological meaning of the name of the pump is of interest. The prefix “turbo” is a shortened version, introduced into the technical lexicon since 1900, of the term “turbine”. Both of these words come from the French. “turbine” - “turbine”, and earlier from lat. “turbo”, meaning “to cause confusion, disturb, whirlwind, top.” The second part of the first word “molecular” comes from Lat. “molecule” - “part, particle”, as a diminutive of “moles” - “mass, lump, bulk”. The next term “pump” is originally ours, Slavic, as it was transformed from the Old Orthodox words “suck, ssati, ss”, meaning “suck breast milk”, “suck the brain bones”, “draw out liquid”.

In this article we will look at:

• pfeiffer turbomolecular pump;
• turbomolecular pump agilent tv81m;
• high-vacuum turbomolecular pump twistorr 84 fs;
• turbomolecular pump tg350f;
• power supply unit for turbomolecular pumps type bp 267;
• turbomolecular pump operating principle;
• molecular vacuum pump;
• molecular pump mdp 5011 price;
• buy a turbopump;
• turbopump price;
• disadvantages of turbopumps;
• turbomolecular pump TMN 500;
• pump TMN 200;
• dry pump;
• oil-free vacuum pump;
• oil-free foreline pumps;
• dry type vacuum pump;
• oil-free rotary vane vacuum pump;
• oil-free vacuum piston pump;
• fore-vacuum pump 2nvr 5dm.

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In 1913, the German scientist Wolfgang Goede published in the journal Annalen der Physik a description of a new vacuum pump, for which the laws of the molecular kinetic theory of gas movement were used. For the purpose of experimental verification, he manufactured the first vacuum molecular pump with minimum clearance 0.1 mm between the rotor, rotating at about 8000 rpm, and the stationary stator. A gas vacuum of up to 10 -4 mm Hg was obtained. The new pump even began to be produced by the German company Leybold’s Nachfolgers, but was not widely used. Firstly, there was no urgent need for it, and secondly, technological difficulties with the manufacture of such small gaps interfered. Macroscopic solid particles (pebbles, chips, glass) entering the pump along with the gas led to jamming of the rotor.

In the late 1950s there was renewed interest in molecular pumps

Only at the end of the 50s of the last century was interest in molecular pumps renewed, when the German engineer W. Becker invented the Pfeiffer turbomolecular vacuum pump with a large number bladed disks on the shaft and with increased gaps, about 1 mm. This pump was patented in 1957 by Pfeiffer Vacuum. Further, the design and principle of operation of TMN pumps continued to be improved, such designs as the Agilent TV 81M turbomolecular pump and the latest (2015) high-vacuum turbomolecular pump Twistorr 84 FS from the Italian company Agilent Technologies, the hybrid turbomolecular pump TG 350F from the Japanese company Osaka Vacuum and others appeared. Moreover, the components of these devices are often interchangeable. For example, a power supply unit for a turbomolecular pump type BP-267 can be used for pumps of models NVT-340, NVT-950, 01AB-450, 01AB-1500.

In a molecular pump, pumping out a gaseous medium is carried out by imparting mechanical impulses of energy to the molecules of the substance from solid, liquid, and gaseous surfaces of the pump moving at high speed. Moreover, in a molecular pump the direction of movement of the working surfaces and gas molecules coincide, and in a turbomolecular pump the directions of movement of the working elements and molecules are mutually perpendicular.

Cross-sectional image of a molecular pump

Based on their operating principle, molecular pumps are divided into:

• mechanical (rotor and turbine);
• ejector;
• steam jet;
• gas jet;
• water jet;
• diffusion

For example, the MDP 5011 high-vacuum molecular pump is a device with mechanical operating elements. The movement of gas molecules to the pump outlet is ensured by the solid surface of the rotor-glass, which rotates at 27,000 rpm. This model MDP 5011 is the best-selling turbopump. Clearly, you are interested in the price of the MDP5011 molecular pump. Please contact us for such questions, call, write to email. We will advise and help.

The turbopump is pumping device driven by a turbine, the components and parts of which are included in the design of the pump. The following types of turbopumps are distinguished depending on the type of pumped working medium.

Appearance of turbopumps

1. Turbopumps for pumping liquids.
2. Turbopumps for pumping suspensions.
3. Turbopumps for pumping gases.

The disadvantages of turbopumps include the complexity of the design, long downtime when repairing the pump or turbine, high cost. Therefore, if you need to buy an oil turbopump TMN-6/20, the question naturally arises, what is the price of the turbopump. If you are not satisfied with it in other companies, come to us.

Turbomolecular pumps (TMP) are designed as multi-stage axial turbines that achieve medium, high and ultra-high vacuum. The special design of the rotor and stator stages of the turbine, in which inclined channels are made, placed mirror to each other, makes it possible to effectively pump out gas molecules due to the different probability of molecules passing through the channels located at an angle in the pumping and supply directions. TMPs are fixed to a massive base through shock absorbers, which reduces vibration during the pumping process.

Appearance of the turbomolecular vacuum pump TMN-500

The operating principle of a turbomolecular pump is as follows. The energy of the turbine blades, rotating at high frequency, is transferred to the gas molecules. The latter collide with the surfaces of the blades, move together for a split second and fly off tangentially to the rotating turbine. The kinetic energy of the blades is summed up with the thermal energy of the moving gas particles. The chaotic movement of molecules turns into accelerated movement in a given direction of pumping. Such effective operation of the rotor is possible only in the molecular gas flow mode, which is created by an additional low-pressure fore-vacuum pump.

Domestic double-flow oil-free pumps make a good impression: the TMN-500 turbomolecular vacuum pump and the TMN-200 pump with a capacity of 500 and 200 l/sec, respectively. Of course, in terms of build quality and design they are inferior foreign analogues. But at a low cost, they are characterized by operational reliability, reliability and sufficient durability.

A dry (oil-free) vacuum pump works in the same way as an oil-based one. But a dry-type pump does not use oil to lubricate rubbing parts, and there are no sealing devices. Therefore, the material used for the blades of dry pumps is not metal, but a graphite composite material. Graphite blades are cheaper than metal blades made of titanium, aluminum, stainless steel, are characterized by a lower coefficient of friction and reliably seal the pump chamber.

Appearance of a dry vacuum pump

Advantages of oil-free vacuum pump:

• absence of oil vapor when air exits the pump, workplace becomes clean, the environment improves;
• no need to purchase and fill expensive oil, monitor its level and contamination;
• lower cost.

Disadvantages of a dry pump:

• the depth of the vacuum created is lower than that of oil-sealed pumps;
• the durability of graphite blades is significantly less than that of metal blades;
• wear products in the form of dusty graphite enter the atmosphere.

However, experts believe that oil-free vacuum pumps are the future. And now they are already trying to buy an oil-free rotary vane vacuum pump, an oil-free piston vacuum pump, an oil-free fore-vacuum pump, without paying attention to their price. Since the simpler and cheaper operation of a dry pump will pay for all the initial costs.

A fore-vacuum pump is a device for creating an initial rarefaction of a gaseous medium - a fore-vacuum (from the German “vor” - “in front of, in front” of the vacuum and the Latin “vacuus” - “empty”). The principle of operation is that the foreline pump is installed as the first stage in a system of pumps that create high and ultra-high vacuum. Provides energy savings and improves the ability to operate the next high stage pump.

The most suitable for this purpose is the domestic rotary vane forevacuum pump 2NVR-5DM, designed both for creating low and medium vacuum independently and as an auxiliary pump.

Appearance of the fore vacuum pump 2NVR-5DM

If you are interested in the described turbomolecular and forevacuum pumps from our company’s product range, you can get more detailed information from consultants. Our highly qualified specialists will help you choose the optimal pump option, explain the terms of purchase, operation and service, and justify prices. They will assist you in selecting spare parts and auxiliary materials, for example, such as blades for Becker oil-free pumps, oil for foreline pumps and others. Call our phones or contact us by E-mail. We will be happy to help you.