Vacuum pumps are widely used in the most various industries industry and science. The main application of vacuum pumps is to remove air or gas from a hermetically sealed volume and create a vacuum in it. We will consider the most common types, characteristics of vacuum pumps, their principle of operation and main applications.

Vacuum pumps are classified according to the operating pressure range into:

• primary (foreline) pumps,
• booster pumps
• secondary pumps.

In each pressure range, different types of vacuum pumps are used, differing from each other in design. Each of these types has its own advantage in one of the following points: possible pressure range, performance, price and frequency, and ease of maintenance.

Regardless of the design of the vacuum pumps, the basic operating principle is the same. The vacuum pump removes air and other gas molecules from the vacuum chamber (or from the outlet of a higher pressure vacuum pump if connected in series).

As the pressure in the chamber decreases, the subsequent removal of additional molecules becomes exponentially more difficult. Therefore, industrial vacuum systems must cover a large pressure range from 1 to Torr. In the scientific field this indicator reaches torr or lower.

The following pressure ranges are distinguished:

• Low vacuum:> from atmospheric pressure to 1 torr
• Medium vacuum: 1 torr to 10-3 torr
• High vacuum: 10-3 torr to 10-7 torr
• Ultra-deep vacuum: 10-7 torr to 10-11 torr
• Extreme high vacuum:< 10-11 торр

Compliance of vacuum pumps with pressure ranges:

Primary (foreline) pumps - low vacuum.

Booster pumps - low vacuum.

Secondary (high vacuum) pumps: High, ultra deep and extremely high vacuum.

Classification of vacuum pumps according to the principle of operation with gas

There are two main technologies for working with gas in vacuum pumps:

• Gas pumping
• Gas capture

Pumps operating on gas transfer technology are subdivided into kinetic pumps and positive displacement pumps.

Kinetic pumps operate on the principle of transferring momentum to gas molecules from high-speed blades to ensure a constant movement of gas from the pump inlet to the outlet. Kinetic pumps are usually not leak-tight. vacuum chambers but can achieve high compression ratios at low pressures.

Positive displacement pumps work by mechanically capturing a volume of gas and moving it through the pump. In a sealed chamber, the gas is compressed to a smaller volume at a higher pressure and after that, the compressed gas is displaced into the atmosphere (or into the next pump).

Typically, kinetic and volumetric operate in series to provide higher vacuum and flow rates. For example, very often a turbomolecular (kinetic) pump is supplied assembled in series with a screw (positive displacement) pump into a single unit.

Gas capture technology pumps capture gas molecules on surfaces in vacuum system... These pumps operate at lower flow rates than transfer pumps, but can create ultra-high torr and oil-free vacuums. Trap pumps operate using cryogenic condensation, ionic reaction or chemical reaction and have no moving parts.

Types of vacuum pumps depending on the design

Depending on the design, vacuum pumps can be divided into oil (wet) and dry (oil-free), depending on whether the gas is exposed to oil or water during pumping.

A wet pump design uses oil or water to lubricate and / or seal. This liquid can contaminate the pumped gas. Dry pumps have no liquid in the flow path and depend on the sealed gaps between the rotating and static parts of the pump. The most commonly used seal is polymer (PTFE) or a diaphragm to separate the pump mechanism from the pumped gas. Dry pumps reduce the risk of oil system contamination compared to wet pumps.

The following designs, described below, are most often used as primary (foreline) pumps.

Primary foreline pump. Principle of operation. Design options

Oil Filled Rotary Vane Pump

(wet, voluminous)

In a rotary vane pump, gas enters the inlet and is captured by an eccentrically mounted rotor, which compresses the gas and transfers it to the outlet valve. A spring-loaded valve allows gas to escape when atmospheric pressure is exceeded. The oil is used to seal and cool the blades. The pressure achieved with a rotary pump is determined by the number of stages. The two-stage design can provide a pressure of 1 × 10-3 mbar. The capacity ranges from 0.7 to 275 m3 / h.

Liquid ring vacuum pump. Design and principle of operation

(wet, voluminous)

The liquid ring pump compresses the gas by means of a rotating impeller located eccentrically inside the pump housing. The liquid is fed into the pump and forms a cylindrical moving ring by means of centrifugal acceleration. This ring creates a series of seals in the spaces between the impeller vanes, which are the compression chambers. The eccentricity between the axis of rotation of the impeller and the pump casing leads to a decrease in the volume between the impeller blades and thus to the compression of the gas and its release through the outlet pipe. This pump has a simple, solid construction since the shaft and impeller are the only moving parts. The liquid ring pump has a large power range and can provide a pressure of 30 mbar when using water with a temperature of 15 ° C. When using other fluids, lower pressures are possible. The range of available capacities is from 25 to 30,000 m3 / h.

Diaphragm vacuum pump

(dry bulk)

Diaphragm pumps use a flexible diaphragm that is connected to the stem and moves alternately in opposite directions so that gas enters the space above the diaphragm and fills it completely. Then the intake valve closes and the exhaust valve opens to release the gas.

The diaphragm vacuum pump is compact and very easy to maintain. Diaphragms and valves typically have a service life of over 10,000 operating hours. A diaphragm pump is used to support small turbomolecular pumps in a clean, high vacuum. This is a pump low power, widely used in research laboratories for sample preparation. Typical ultimate pressure 5 × 10-3 mbar. Capacity 0.6 to 10 m3 / h (0.35 to 5.9 cfm).

Spiral vacuum pump

(dry bulk)

The main elements of the pump are spiral rotor and stator. The expanded gas enters large circular spaces that taper when it reaches the center of the spiral rotating rotor. A PTFE polymer seal provides a seal between the pump scroll elements without using oil in the pumped gas. The attainable pressure is 1 × mbar. Productivity from 5 to 46 m3 / h.

Booster pumps

Double rotor vacuum pump

(dry bulk)

Twin-rotor pumps are mainly used as booster pumps and are designed to remove large volumes of gas. The two rotors rotate without touching each other to continuously transfer gas in one direction through the pump. This increases the performance of the primary / foreline pump by increasing the pumping rate to approximately 7: 1 and improving the final pressure to approximately 10: 1. Booster pumps can have two or more rotors. Typical ultimate pressure<10-3 Торр может быть достигнуто (в сочетании с первичными насосами). Производительность составляет подобных агрегатов может достигать около 100 000 м3/ч.

Cam-gear pump

(dry bulk)

The lobe-toothed pump has two lobes that rotate in opposite directions. The operation of a vacuum pump is similar to that of a rotary pump, except that the gas is conveyed axially and not from top to bottom. Very often a lobe pump and a twin-rotor pump are used in combination. Rotor stages and cam stages are installed on one common shaft. This type The pump is designed for harsh industrial conditions and provides high performance. Typical ultimate pressure 1 × 10-3 mbar. The productivity is from 100 to 800 m3 / h.

Screw pump

(dry bulk)

The main working parts of the unit are two rotating screws that do not touch each other. Rotation carries gas from one end to the other. The screws are designed in such a way that as the gas passes through them, the space between them becomes smaller and the gas is compressed, thereby causing a reduced inlet pressure. This pump has a high performance. The PCP can handle fluids and impurities and also works well under harsh conditions. Typical ultimate pressure is about 1 × 10-2 Torr. The capacity can reach 750 m3 / h.

Secondary (high vacuum) pumps

Turbomolecular pump

(dry, kinetic)

Turbomolecular pumps work by transferring kinetic energy into gas molecules using high-speed rotating angled vanes that propel the gas at high speeds. The rotation speed of the blade tip is usually 250-300 m / s. Receiving momentum from the rotating blades, the gas molecules move to the outlet. Turbomolecular pumps provide low pressure and low performance parameters. Typical ultimate pressure is 7.5 x 10-11 Torr. Performance range from 50 to 5000 l / s. Pumping stages are often combined with stagnation stages, which allows the turbomolecular to reach higher pressures (> 1 torr).

Diffusion steam oil pumps

(wet, kinetic)

Steam diffusion pumps transfer kinetic energy to gas molecules using a high speed heated oil stream that moves the gas from the inlet to the outlet. This provides a reduced inlet pressure. This design is rather outdated. To a large extent they are being supplanted in the market by the more convenient dry turbomolecular pumps. Oil diffusion pumps have no moving parts and are highly reliable. This vacuum pump has a low price. Ultimate pressure less than 7.5 x 10-11 Torr. Performance range 10 - 50,000 l / s.

Cryogenic pump

(dry, gas recovery technology)

Cryogenic pumps work by capturing and storing gases and vapors, rather than pumping them through themselves. This type of pump uses cryogenic technology to freeze or trap gas on a very cold surface (cryocondensation or absorption) at a temperature of 10 ° K to 20 ° K (minus 260 ° C). These pumps are very efficient but have limited gas storage capacity. The collected gases / vapors must be periodically removed from the pump, heating the surface. They are pumped out using another vacuum pump. This process is also known as regeneration. Cryogenic pumps require the installation of an additional compressor cooling system to create cold surfaces. These pumps can reach pressures of 7.5 x 10-10 Torr and have a capacity range of 1200 to 4200 l / s.

Major manufacturers of vacuum pumps

The vacuum pump can be purchased from the following manufacturers

BUSCH www.buschvacuum.com

Becker www.beckerpumps.com

Elmo Rietschle http://www.gd-elmorietschle.com/en

NASH http://www.gdnash.com/liquid_ring_vacuum_pumps/

Robuschi http://www.gardnerdenver.com/en/robuschi/products/vacuum-pumps

Pfeiffer Group group.pfeiffer-vacuum.com

Samson Pumps www.samson-pumps.com

In various spheres of human activity, the creation of 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 of mercury or pascals. The rarefaction of gases occurs when the substance is forcibly removed from devices with a limited volume. Technical device designed for this purpose is called a vacuum pump. It can be used on its own or as part of more complex systems.

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

• in the oil refining and chemical industries to maintain the necessary conditions for the reactions and separation of the resulting mixtures;
• when degassing metals and other materials to create parts with a homogeneous structure and the absence of pores;
• in the pharmaceutical and textile industry for quick drying of products without increasing the temperature;
• v Food Industry when packing milk, juices, meat and fish products;
• in the process of evacuating 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 operation breathing apparatus and dental offices;
• in the printing industry for fixing thermal films.

How vacuum pumps work

The vacuum is created when mechanical removal substances from a closed space. Technically it is implemented different ways... Principle of operation jet type vacuum pump It is based on the entrainment of gas molecules by a stream of water or steam escaping at a high speed from the ejector nozzle. Its scheme provides for the connection of a side pipe, in which a vacuum is created.

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

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

The main varieties of vacuum pumps

In the manufacture of devices for creating a vacuum, metal and plastic materials resistant to the chemical attack of the pumped medium and possessing sufficient mechanical strength. Much attention is paid to the accuracy of fitting the assemblies and the tightness of the contact surfaces, excluding the backflow of gases. Here is a list of the main types of vacuum pumps, which differ in design and principle of operation.

Liquid ring

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

When the engine is started, the impeller accelerates the water along the inner walls of the housing. A crescent-shaped vacuum area is formed between it and the rotor. Gas rushes into it from the inlet of the pump. Moving vanes move it along the shaft and eject it through the outlet. Aggregates of this type are often used also for partial gas cleaning due to its intense contact with water.

The use of a liquid as a working body offers many advantages.

1. The water rotating in the space between the rotor and the pump casing eliminates the possibility of backflow of gases, replacing the seals and reducing the requirements for the accuracy of parts manufacturing.
2. All rotating parts of the pump are constantly washed with fluid, which reduces friction and improves heat dissipation.
3. Such devices rarely require repair, have long term service and consume a minimum of electricity.
4. Working with gases containing water droplets and small mechanical impurities does not provide negative impact on the technical condition of the 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.

Rotary vane

These pumps have a cylindrical casing with a carefully polished inner surface and a rotor located inside it. Their axes do not coincide, so the side clearance has different values. The rotor includes special movable plates, which are pressed by springs to the body and divide the free space into sectors of variable volume. When the engine is turned on, the gases are set in motion so that a vacuum is always created in the inlet pipe, and overpressure in the discharge pipe.

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

Diaphragm piston

The working body of the pumps of this principle of operation is flexible membrane associated with the linkage. It is made from modern composite materials resistant to mechanical stress. Its edges are firmly fixed in the body, and the central part bends under the action of an electric or pneumatic drive, alternately reducing and increasing the space of the inner chamber.

The change in volume is accompanied by the suction and expulsion of incoming gases or liquids. At working together in antiphase of the two membranes, a continuous pumping mode is ensured. The valve system regulates the correct distribution and direction of flows. The mechanism has no 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, excluding leaks;
• high efficiency;
• ease of flow control;
• long-term operation in dry mode, which does not damage the structure;
• the ability to use a pneumatic actuator to work in an explosive environment.

Screw

The principle of operation of screw pumps is based on displacement of liquid or gas along the rotating screw. They consist of a drive, one or two helical 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 at the inlet.

Such equipment is not cheap because of the high quality requirements. It cannot be kept in dry mode for a long time.

The main advantages of such pumps:

• uniformity of consumption;
• low noise level;
• the ability to pump liquids with mechanical impurities.

Vortex

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

The minimum clearance between the impeller and the casing ensures stable movement of the pumped liquid in the required direction. Aggregates of this type are capable of creating sufficient high pressure discharge and have a self-priming effect. These pumps are easy to operate, easily repaired and have proven themselves excellent when pumping gas-liquid mixtures, but they have low efficiency. They are sensitive to the ingress of mechanical impurities that can lead to rapid wear of the impeller.

Self-made vacuum pump

If you are not willing to bear the costs of purchasing factory equipment, try making your own vacuum pump. For pumping air from a container of small volume, it may be suitable a medical syringe or a slightly modified hand bicycle pump.

Advice! With frequent use and evacuation of large vessels, it is more convenient to use devices with an electric drive.

Consider the manufacturing option vacuum unit 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 suitable for him;
• dismantle the compressor together with the power supply circuit or replace it together with the starting relay with a new one, by analogy with the old one;
• on the copper pipe that came from the condenser, put on a durit hose of a suitable diameter and connect it with the other end to the evacuated container;
• for the tightness of the connection, you can use a standard clamp or use a twist of steel wire;
• connect the vacuum pump to electrical network and after starting on the air outlet from the second copper pipe, make sure that it works correctly.

Important! The compressor of the refrigerator is not intended for operation in a humid environment, therefore it must be ensured that no water gets on it.

Basic principle of any type of vacuum pump Is repression. It is the same for all vacuum pumps of every size and every application. In other words, operating principle of the vacuum pump is reduced to the removal of the gas mixture, steam, air from the working chamber. During the displacement process, the pressure changes and the gas molecules flow in the desired direction.

Navigation:

Two important conditions, which the pump must perform, is to create a vacuum of a certain depth by pumping out the gas medium from the required space and to do this within a given time. If any of these conditions are not met, then you have to connect an additional vacuum pump. So, if the required pressure is not provided, but for the required period of time, the foreline pump is connected. It further reduces the pressure so that all the necessary conditions... This operating principle of the vacuum pump is similar serial connection... Conversely, if the pumping speed is not ensured, but the desired vacuum is achieved, then another pump will be required to help achieve the required vacuum faster. This principle of operation of a vacuum pump is similar to a parallel connection.

Note. The depth of the vacuum created by the vacuum pump depends on the tightness of the working space, which is created by the pump elements.

To create a good tightness of the working space, a special oil is used. It seals the gaps and bridges them completely. A vacuum pump with such a device and operating principle is called an oil pump. If the principle of a vacuum pump does not involve the use of oil, then it is called dry. Dry vacuum pumps have the advantage of using them, since they do not require maintenance with oil changes and so on.

Except vacuum pumps industrial use, small pumps that can be used at home are widely used. These include a hand-held vacuum pump for pumping water from wells, reservoirs, pools and more. The principle of operation of a manual vacuum pump is different, it all depends on its type. The following types of manual vacuum pumps are distinguished:

1. Piston.
2. Rod.
3. Wing-type.
4. Membrane.
5. Deep.
6. Hydraulic.

Piston vacuum pump works due to the movement of the piston inside it with valves in the middle of the body. As a result, the pressure decreases and water rises through the bottom valve while the piston handle moves down.

Rod vacuum pump It is similar in principle to a piston, only a very elongated rod plays the role of a piston in the body.

Vane vacuum pump has a completely different principle of operation. Pressure in working chamber the pump is created by the movement of the impeller with blades (impeller). In this case, the water rises along the wall of the chamber, this increases the pressure and, the water splashes out.

More complex design is an rotary vacuum pump... But this complexity is compensated by the fact that the pump is capable of pumping not only water, but also heavier oil liquids. The pressure in the pump is created by a rotor with thin plates that rotate and, with the help of centrifugal force, draw the liquid into the container, and then by physical force pushes it out.

Diaphragm vacuum pump does not have any rubbing parts, therefore it can be used for pumping very dirty mixtures. A vacuum is created using an internal pendulum and a membrane, which moves the liquid through the housing to the desired location. To prevent the body from jamming from accidentally lingering debris, the pump is equipped with special valves that clean the pump.

Deep well vacuum pump able to lift water from very great depths (up to 30m). Its principle of operation is the same as that of a piston, but with a very long rod.

Hydraulic vacuum pump handles viscous substances well, but wide application he didn't get it. We will consider in more detail the principle of operation and the device of vacuum pumps in its individual types.

The principle of operation of liquid ring vacuum pumps

One of the types of vacuum pumps is a liquid ring vacuum pump, its principle of operation is based on the creation of a tightness of the working volume with the help of a liquid, namely water.

Let's consider in detail the liquid ring vacuum pump and its principle of operation. Inside the body of the liquid ring pump there is a rotor, which is offset from the center slightly upward. The rotor has an impeller with blades rotating during operation. Water is pumped into the housing. When the wheel moves, the blades capture water and throw it towards the body by centrifugal force. Since the rotation speed is high enough, the result is a water ring around the circumference of the body. In the middle of the case, a free space is obtained, which will be the so-called working chamber.

Note. The tightness of the working chamber is ensured by the surrounding water ring. Therefore, these pumps are called liquid ring vacuum pumps.

The working chamber is crescent-shaped, and it is divided by the blades of the wheel into cells. These cells are obtained different sizes... During movement, the gas moves alternately through all the cells, heading in the direction of decreasing volume and at the same time contracting. This is how it goes a large number of times, the gas is compressed to the required value and exits through the discharge port. When the gas passes through the working chamber, it is cleaned and comes out already clean. This property is very useful for pumping contaminated media or steam-saturated gaseous media. During operation, the vacuum pump constantly loses a small amount of working fluid, therefore, a reservoir for water is provided in the design of the vacuum system, which then, according to the principle of operation, returns back to the working chamber. This is also necessary because gas molecules, while contracting, give up their energy to water, thereby heating it. And to avoid overheating of the pump, the water is cooled in such a separate tank.

You can see in detail how the liquid ring vacuum pump works and how it works in the video below.

Operation of rotary vane pumps

The rotary vane vacuum pump is one of the oil pumps. In the middle of the body there is a working chamber and a rotor with holes, which is located eccentrically. The rotor has blades that can move along these slots under the influence of springs.

Having considered the device, now we will consider what the principle of operation of rotary vacuum pumps is. Gas mixture enters the working chamber through the inlet, moves through the chamber under the influence of the rotating rotor and blades. The working plate, pushing from the center with the spring, covers the inlet, the volume of the working chamber decreases, and the gas begins to compress.

Note. During gas compression, condensation may occur due to steam saturation.

When the compressed gas is released to the outside, the resulting condensate is released along with it. This condensate can adversely affect the operation of the entire pump, therefore, it is still necessary to provide a gas ballast device in the design of rotary vane pumps. You can schematically see how a rotary vane vacuum pump works, its principle of operation, in the figure below using a Busch R5 pump as an example. As mentioned, a rotary vane pump is an oil pump. Oil is needed to close all gaps and gaps between the blades and the casing, and between the blades and the rotor.

The oil in the working chamber is mixed with the air, compressed and released into the oil container. Air mixture the lighter one passes into the upper chamber of the separator, where it is finally cleared of oil. And the oil, the weight of which is greater, settles in the oil container. From the separator, the oil returns to the inlet.

Note. High-quality pumps clean the air very thoroughly, there is practically no oil loss, therefore, it is extremely rare to add oil to such pumps.

The principle of operation of the VVN pump

VVN is a water vacuum pump, the operating principle of which is the same as that of a liquid ring vacuum pump.

The working fluid of the VVN pumps is water. The diagram shows a simple principle of operation of the VVN pump.

The movement of the VVN pump rotor occurs directly by the engine through the clutch. This provides high revolutions to the rotor, and as a result, the possibility of obtaining a vacuum. True, the VVN pumps can only create a low vacuum, because of this they are called pumps low pressure... Simple VVN pumps can pump gases saturated with vapors, contaminated media, and at the same time clean them. But the composition must be non-aggressive so that the cast iron parts of the pump are not damaged as a result of reaction with the chemical compositions of the gas. Therefore, there are models of VVN pumps, parts of which are made of titanium alloy or nickel-based alloy. They can pump out any mix without fear of damage. The VVN pump, due to its principle of operation, is performed only in a horizontal version, and the gas enters the chamber from the top along the axis.

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

The world leader in the design and manufacture of "dry" vacuum pumps is the English company Edwards. Edwards is the pioneer in dry gas pumping. More than 90 years of experience in vacuum pump applications in different conditions operations, including processes with a high content of dust and dirt, and more than 150,000 delivered dry vacuum pumps worldwide, provide the most intelligent solution to the problem of dry vacuuming.

Dry pumping technology provides a significant reduction in operating costs, an increase in productivity, an increase in product quality, and the creation of more favorable conditions labor in working rooms. 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 media with the greatest permissible pressure water vapor at the pump inlet, several times higher greatest pressure water vapor for pumps with an oil seal, moreover, 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, Drystar's claw-gripping dry vacuum technology was an innovation in the vacuum world and continues to enjoy well-deserved popularity around the world today.

So, the first models of pumps from Edwards, with a claw mechanism, of the Drystar trademark, were the GV series pumps, which are now installed all over the world in a variety of general industrial technological processes, in metallurgy, in drying processes, surface treatment, and in the production of semiconductor devices. The principle of operation of GV pumps is based on the claw gripper mechanism, and the additional Roots stage used in the design of the pumps allows to increase the pumping speed in the operating range and achieve maximum speed of action.

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

In parallel with the dry pumping technology with a claw gripping mechanism, the evacuation technology with screw rotors of pumps was developed.

The IDX Series Progressing Cavity Pumps are ideal for processes requiring high performance in vacuum or rapid evacuation from atmospheric pressure. The pumps use a unique double-sided symmetrical screw mechanism, which simplifies the compensation system for thermal expansion of the shafts. This design, which has no analogues in the products of other manufacturers, allows you to easily pump gas environments 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. IDX pump systems are the standard solution in steel evacuation processes.

Later, by analogy with the appearance of the "chemical" versions of the GV-EDP pumps, screw pump CDX, which is a modification of the IDX pump, but has a number of features that allow it to be used in chemical and petrochemical industries.

In combination with EH / HV / SN booster pumps, dry vacuum pumps of the GV, EDP, IDX series can achieve a capacity of up to 120,000 m 3 / h. How special case- IDX based systems for metallurgy, representing ready-made solutions for ladle furnace systems for 50, 100 and 150 tons (vacuum degassing VD and vacuum decarbudization VOD). The pumping speed can be varied by adding additional stages, which allows the design of evacuation systems that meet the needs of a particular process.

At present, a new generation of vacuum pumps for general industrial processes, the screw type GXS pump, has gained widespread acceptance. This pump is a completely turnkey solution, the pump is ready for operation immediately upon delivery. It is equipped with a control panel located directly on the body, and also has a number of additional options that allow you to configure the system to fully meet the needs of a particular customer. The wide range of GXS pumps can be presented both in the form factor of a single-stage pump, and in combination with a booster pump (in a single housing), which allows to provide capacities from 160 to 3'500 m 3 / h.

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

For more details on the capabilities and characteristics of Edwards dry vacuum pumps, you can find 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

Screw vacuum pump DRYVAC from Leybold GmbH (Germany)

The principle of operation, based on the rotation of the screws, allows for the evacuation of gas without the presence of oil in the area of ​​compression. The DRYVAC screw vacuum pump has a compression cavity formed by the surface of the housing, as well as two rotors that rotate synchronously. Due to the fact that the rotors rotate in opposite directions, there is a gradual movement of the compression cavity from the suction side towards the exhaust side, which ultimately provides the necessary pumping effect.

Despite the fact that the process of internal compression of the gas occurs in the considered design, the "particle path" in the internal space of the pump is minimal. A similar feature significantly simplifies maintenance, and also reduces the need for service work to the possible minimum.

The DRYVAC range is a new series of oil-free screw vacuum pumps. The configuration, which can be different, must be selected taking into account the field of application, as well as other individual criteria.

During the development of the series, the actual needs of the processes were taken into account, in which the requirements for vacuum pumping systems are quite high. The considered devices are used, in particular, in the manufacture of screens, photovoltaic elements, as well as for a number of other industrial applications.

Each version of the pump from the DRYVAC line is equipped with water cooling, which makes it a compact design and the ability to be relatively easy to install even in complex systems in parallel with the reliable RUVAC pumping units of the WH, WS and WA series.

The DRYVAC range of screw vacuum pumps includes:

• model DV 450
• model DV 450S
• model DV 650
• model DV 650-r
• model DV 650 S
• model DV 650 S-i
• model DV 650 C
• model DV 650 C-r
• model DV 1200
• model DV 1200 S-i
• model DV 5000 C-i