Vacuum receiver device. The design of the vacuum system with a two-rotor roots pump. How is medical vacuum system applied

To date, there are many types of vacuum pumps that differ in the specifics of their work, although they have general principle actions. They are used both for domestic needs and in large enterprises for very serious work.

There are devices for milking cows (vacuum pump UVD 10), laboratory units, an electric vacuum apparatus, etc. The scope of these types is clear and common man, but the principle of operation of a vacuum pump, unfortunately, is much more complicated.

1 area of ​​use

The invention of such devices makes it possible to cope with a variety of tasks that require human intervention.

The vacuum pump and container are used in the industrial field and with their help they solve many problems:

• protection of nature (containers for cleaning);
• polygraphy (preparation and copying of drawings, where the 2NVR apparatus is used);
• food production (meat processing, milking cows ATC 10,000 with a vacuum pump, apparatus 461M, a set of vacuum containers with a pump for packaging, lids with a pump for cans, etc.,);
• medicine (medical vacuum device for breathing apparatus, mini-tubes in dentistry that use the HBM 5 device);
• glass production and ceramic products, where 2NVR and 5DM containers are most often used;
• the woodworking industry, where 2HBP and vacuum containers are popular, and for drying wood, the installation of a vacuum pump VVN 1 075 will be excellent.

1.1 Features of the devices

Each vacuum system has its own advantages due to the principle of operation and some features.

For example, a water vacuum pump is robust and can be used at maximum high temperatures. It is mainly used for pumping steam, gas and air. highly demanded in industrial applications. There are three types of water unit for creating a vacuum:

• single-stage with one chamber;
• single-stage with two chambers;
• two-stage with two chambers.

The screw vacuum pump has its advantages: it does not consume oil in operation and can do without installing a condenser. This oil-free machine greatly saves energy consumption.

1.2 Working principle of the vacuum pump

Operating principle this device is based on the following tasks: it must create a pressure drop in the working closed space and do it in a certain time.

To prevent gas leaks through the gaps of parts, they are used for vacuum pumps. With the help of such oil, the gaps are sealed, which allows them to be completely blocked. It follows from this that pumping systems that use vacuum oil are called oil pumps. And devices where such oil is not used are called dry. If you have to choose between these devices, then the most the best option there will be a choice of a dry apparatus, because it does not need to be serviced.

1.3 How does a vacuum pump work? (video)

1.4 Types and differences

Depending on the pressure range within which it is possible to achieve the maximum performance of the vacuum pump, the devices are divided into three types:

• foreline pump;
• high vacuum;
• booster (intermediate vacuum).

1.5 Forevacuum apparatus

Foreline pumps are devices for preliminary vacuum. They are used to ensure operation in high vacuum conditions. Foreline pumps are excellent energy savers, which is a great advantage over their counterparts . As such a unit, rotary-plate devices are used.(one of the cheapest 2NVR 5DM), as well as a steam-oil apparatus, turbomolecular vacuum pumps, etc.

1.6 High vacuum pumps

These devices are not connected directly to the system, but through communications. It is recommended to install shutters between the device and the system itself, as they allow you to disconnect the device from the system. Together with dampers, traps are installed for cooling and trapping the vapor of the working medium, which enters the system from the apparatus.

2 Manual vacuum pump

Such a device can be made independently using the usual. The syringe is an excellent pump, which is quite cheap and can be purchased at any pharmacy.

3 Common models

3.1 Becker

Vacuum devices Becker (Becker) have proven themselves in pumping gases, air, industrial emissions, as well as in industrial sectors. For example, an oil-free rotary vane is designed to create a clean, dry vacuum and blow air that is free of foreign particles.

3.2 Bosch

The Bosch vacuum pump is installed in light diesel and light commercial vehicles. It creates a vacuum in brake system and in the turbocharger system.

3.3 Rietschle

German factory Elmo Rietschle offers a wide range of Rietschle vacuum pumps:

• production of centrifugal pump;
• vortex;
• water ring;
• lamellar-rotor;
• cam;
• screw.

Products German company is different high quality production, which has been tested for decades of flawless work.

3.4 AVZ 180

The manufacturer of the vacuum pump AVZ 180 is Ukraine. It works with non-flammable gas without moisture and abrasive. I use this device for medical purposes, Agriculture, in the production of metals, etc. Sometimes this device is installed as a fore vacuum for the Roots pump.

3.5 AVZ 20D

The AVZ 20D spool apparatus is used to pump out air, a vapor-gas mixture, previously cleaned of small particles. The temperature of the working environment AVZ 20D is 10-35˚С. The device is not used for pumping the working medium from one container to another. The AVZ 20D device is unsuitable for working with an aggressive environment that reacts with ferrous metal and lubricating oil. The AVZ 20D device must not be overheated; the operation of this device must be with cooling.

3.6 Devices for a vacuum truck

3.7 Graphite blades

Graphite blades are used as accessories for rotary vane and dry vacuum pumps. Graphite blades are popular because they have a number of advantages:

• resistance to adverse conditions, for example, the temperature rises when the blade is rubbed inside the device;
• the blades are inert and not amenable to chemical reactions;
• graphite blades are self-lubricating, which is possible due to the particles that make the lubricant between the chamber of the device and the blade.

Due to the structure, graphite blades are not noisy in operation, which is the main plus.

3.8 Receiver for vacuum device

The receiver for a vacuum pump is called an equalizing cylinder, which is used with vacuum pumps and installations. For chemical and food production receivers with a volume of 500 and 900 liters are made of stainless steel. Economical models of receivers are made on the basis of compressor devices.

The pump has been selected from the series Value iPump for the reason that this series is already equipped with an electromagnetic (solenoid) shut-off valve, which makes further automation a little easier. For other pumps, it will be necessary to purchase and install an additional shut-off valve, which, in principle, will not add much difficulty.

Low power? Partly. The pumping speed is quite enough to work with flat veneer in bags up to 140x200 cm in size.
Single stage? Yes! And why for vacuum veneering the residual pressure is not 20Pa, but 2Pa? The difference in film pressure will be as much as 0.00018 kg/cm2!

Receiver. A rubber membrane was removed from the 24-liter hydraulic accumulator of Gileks, the flange part was cut out, which returned to its place to seal the flange. The nipple for pumping air was plugged and screwed through additional gaskets and washers.

strapping can be assembled from plumbing fittings, which is the most affordable, but Ball Valves it is better to take all the same gas, there is a different stem seal, more suitable for vacuum than in plumbing.
And it can be assembled on special fittings with SAE threads, which are used for vacuuming and filling air conditioning and refrigeration systems. But the price...

Hoses can be taken pneumatic (they say oxygen is better), in which case they will need to be connected to the fittings using clamps. I have often come across the statement that quick couplings for pneumatics are not suitable for vacuum. I did not check the statement, I took my word for it.
And you can use special hoses with SAE threads, which are also used in the commissioning and repair of air conditioning and refrigeration systems.

In this case I used mixed system: piping of water fittings, gas ball valves, adapters with inch thread for SAE threads, hoses with SAE union nuts.
Why is that? I don't like collars :)
By the way, here is such an adapter from inch thread to SAE thread

found only in one place in Moscow and completely at an unreasonable price of 900 rubles!
To order from a turner on the Moskvoretsky market, it cost 500, which is also not cheap, and a sample is needed.

All plumbing connections were assembled on a thread by Tangit and smeared with special silicone vacuum grease. The flange connection of the receiver was also smeared with this grease, as were the balls of ball valves.
The remaining connections perfectly hold the vacuum without additional sealing.

Automation block.
The heart of the block is the Rosma TV-510.05 electrocontact vacuum gauge in the standard version 05, which means that the device has two contacts, the right open, the left closed. For automation, one contact is needed, the left one.

There was a jamb with a domestic commodity producer (if this is also not a Chinese production with our nameplate), on the nameplate of the LRPZ (the left contact is open, the right one is closed), but in fact it is PRLZ.
The scale on the vacuum gauge is not very convenient, each division would need to be multiplied by 10, but you can get used to it.

The electrical part consists of a two-pole machine, a turn-on delay relay, a contactor that starts the pump, all this is placed on DIN rail in a box for 4 IP-65 modules. Near the socket for connecting the pump.

Bag.
Glued together from a PVC film 400 microns thick. Based on the results of gluing experiments, Moment Crystal glue was chosen for gluing, which does not thicken the gluing site, does not reduce elasticity and holds tightly.

The fitting was assembled from plumbing fittings and one "gold" adapter, embedded in a bag. The insertion point is additionally reinforced with two layers of the same PVC film.

A 12 gauge pyzherub was ideal for punching a hole :)
To close the bag I use two bars and three clips.

And yet, it was not without clamps :) for inserting a fuel filter in the role of an air filter into the line for pumping air out of the bag. But then I already gave up, did not look for a suitable filter with desired thread. But he didn't quite give up! Suddenly something similar turns up, then I’ll adapt it :) By the way, when vacuuming, the filter flattens a little, I’m not sure that it will live for a long time.

Well, I had to make a saddle for the pump, because there was no platform on the purchased GA, but just a bracket for attaching to the wall.
At the same time, I added a place to install a box and an outlet.

How it all works:

The vacuum in the receiver can (and should) be prepared in advance, before connecting the bag.

The bag is attached, both taps are opened, the pressure in the combined system decreases, the pump pumps out air from the combined system “station + bag” and then serves to level possible leaks;

The bag is attached, both valves are opened, the pressure in the combined system decreases, the receiver valve is closed, cutting off the receiver from the system, and then the pump works only with the volume of the bag.

The receiver valve is closed, the bag is attached, the bag valve is opened, air is pumped out of the bag, the receiver valve is opened, then the receiver works to level possible leaks.

Or simply close the receiver and work only with the bag, automatics will cope with leaks.

UPD. With a bag, the tightness is not so chocolate, and this is where automation came in handy! :)

The wide range of fore and rotary pump types available provides the designer with the possibility of optimizing according to customer requirements. Below are some interesting examples systems designed for specific applications.

Multistage pumping systems

Multistage pumping systems are typically used when large volumes need to be pumped out in a relatively a short time. Vacuum compressor systems are often used. Also in vacuum systems use a vacuum pump with a vacuum receiver. Vacuum receivers are equalizing vacuum cylinders for use with all kinds of vacuum pumps and vacuum sprayers. We offer vacuum receivers for use in different conditions. At the beginning of pumping from the level atmospheric pressure to maintain an acceptable compression ratio, several stages are used at each stage. As an example, we give a three-stage system connected in series and parallel (Fig. 13), designed to pump out a chamber with a volume of 1308 m 3 from a pressure of 760 Torr to 0.01 Torr in 2 hours with an air leakage of 20 Torr l/s. Starting with the last one, each stage starts sequentially with a time delay of a few seconds in order to reduce the initial power surge. With a 2:1 ratio between the three stages, the interstage bypass valves maintain a maximum allowable relative pressure of 400 Torr. Excess air is released through the valves until the performance of the previous and subsequent fore-vacuum stages is equal. Interstage heat exchangers remove heat from the compressed gas, keep the compression ratio approximately constant, and limit inlet temperatures for subsequent stages. In such systems, the pumping speed of the first stage is maintained at 10270 m 3 /h when pumping from atmospheric pressure to 2 Torr. At 2 Torr, the first and second stages were connected in parallel by valves, providing a speed of 15518 m 3 /h in order to cope with air leakage, which at 0.01 Torr was 7200 m 3 /h. The actual time to reach a pressure of 0.01 Torr was 100 min.

Rice. thirteen. Three-stage vacuum system with series-parallel connection of pumps. pumping out vacuum chamber 1.308 m 3 from 760 to 0.01 Torr in 100 min. with air leakage 20 Torr l/s. Twin rotor pumps are connected in parallel at 2 Torr to handle air leakage at 0.01 Torr (source: Stokes Vacuum Inc.).

Peak power consumption for stages 1 and 2 was 159 and 75 kW, respectively. The average power over the twenty minute period was approximately 60% of peak. Engines with a power of 100 and 56 kW, respectively, were chosen. Overload run time was approximately 3 minutes. High-temperature insulation was used for the windings, and special protection when the temperature was exceeded, it was provided by sensors built into the windings.

Pumping system for pumping liquid hydrogen

The pumping system (Fig. 14) was designed to pump pure hydrogen at a rate of 10200 m 3 /h at 52 Torr 14 K. Due to the increase in heat, the inlet temperature was approximately 249 K. A three-stage pumping system with a liquid seal was chosen to move the cold gas. Ethylene glycol was used as a sealing liquid, which circulated in the system closed loop, where it was heated to 40°C in order to maintain the operating temperature of the rotary pumps. The liquid seal increased the efficiency of the twin rotor pumps, allowing the use of smaller pumps and direct exhaust to atmosphere.

Rice. fourteen. Pumping system for pumping liquid hydrogen. Heated ethylene glycol was injected at the inlet of the twin-rotor pumps to seal and maintain operating temperature(source: Stokes Vacuum Inc.).

Product Vacuum Dehydration System

The product vacuum dehydration system (Fig. 15) was created to obtain a maximum residual pressure of 6 Torr at a speed of pumping air 11.4 kg/h and water vapor 100 kg/h. For this, a system of a two-rotor pump - a condenser - a mechanical pump was used, providing a total pumping speed of the system of 18500 m 3 /h. A twin rotor pump was used to increase the pressure at which the condensers operated - in this case from 6 to 18 Torr. Two condensers, each with receivers, needed to condense and remove all the water when the refrigerator was supplying chilled water at 10°C. An automatically operating pressure control valve located between the condensers and the mechanical pump kept the condensers at 18 Torr to prevent backflow of condensed steam. Most of the water was removed by the condensers, a small foreline pump was used only to pump out air and a small stream of water vapor at a pressure corresponding to the partial pressure of water vapor in the condenser. The foreline pump operated at 82°C.

Rice. fifteen. Product dehydration system. A large mass flow of water vapor (100 kg/h) with a small air flow (11.3 kg/h) were pumped out at 6 Torr. The fore-vacuum pump pumped out air and water vapor at a partial pressure and a condenser temperature of 10 "C (

Medical vacuum systems are designed for serious surgical operations during which removal of excess blood and other fluids is required, as well as drainage of the abdominal and pleural cavities. All operating rooms and wards where intensive care is carried out should be professionally equipped with equipment to maintain the patient's viability at the proper level. That is why a system properly installed and tailored to the needs of the hospital is able to optimize the process of patients' recovery. Medical vacuum stations and systems are the most various kinds and scale.

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Vacuum systems VVN

Used for cleaning in medical facilities. Vacuum pumps are used for pumping out excess air, non-aggressive gases, vapors and gas-vapor mixtures, previously cleaned from dripping moisture and mechanical pollution, from hermetic closed volumes in stationary installations, placed indoors at a temperature of 10 to 30 degrees Celsius. The vacuum pump is designed to maintain a vacuum and provide a given process. Its choice is due to its ultimate pressure and scope.

Vacuum medical systems

Vacuum systems can have one, two or three pumps - it all depends on the appropriateness of use in a particular area. Vacuums based on a single pump are used where it is necessary to constantly maintain a vacuum in the process. The installed vacuum pump provides 100% of the required performance. The pump turns on automatically, depending on the level change in the vacuum. As a rule, medical vacuum systems are smaller and easier to operate than industrial vacuum systems, but they are just as reliable and durable when used. correct use. They can be made in a standard version or have a more mobile look - with a handle for ease of movement by medical staff and wheels.

Vacuum systems based on three rotary vane vacuum pumps are used in NPO test centers or provide central vacuum to a large plant. The main purpose of these devices is to provide consumers necessary level vacuum, regardless of conditions. Without these pumps, hospitals would not be considered modern, and the existence of enterprises and factories is unthinkable, since a failure in production or pollution is undesirable in any area and can negatively affect work.

When buying, you should also focus on the brand, it has proven itself very well in the market German manufacturer Dräger. This company is engaged in the production of high-quality medical vacuum systems. They all adapt to any needs of the medical facility and are made of high quality parts. The control panel of these systems provides many ways to monitor and has alarms.

In total, about 20 parameters are stored in the memory of the control unit, which are responsible for the algorithm of the system. Everything is by default uploaded to the block and ready to be connected. Many parameters can be set by the operator, according to desire or according to the norms of the enterprise, using the buttons on the front panel of the control unit. Medical vacuum systems are equipped with antibacterial filters with a bypass line that replaces filters without disturbing technological process. Powerful vacuum systems – industrial vacuum cleaners to remove dirt and dust at the source of their formation.

All devices in the system are equipped with individual frequency converters, operating, on average, with a capacity of about 65%, and as a result saving energy compared to individual units or installations without speed control.

How the medical vacuum system is applied:

• gas supply for ventilator systems and anesthesia machines;
• drainage of wounds, cavities, including the chest cavity;
• cleaning of endotracheal tubes;
• collection of excess blood and fluids, as well as the contents of the stomach and intestines.

The main parameters for choosing a medical vacuum system:

• gas consumption must correspond to the volume of the receiver and performance;
• power and number of pumps are interconnected;
• limiting and residual pressure - the minimum pressure created by a pump operating without pumping out;
• least operating pressure- the lowest pressure level at which the device operates in normal mode, i.e. pressure in economy mode.

The best-known CPA systems on the market are vacuum plants known worldwide for their reliability. Italian manufacturer D.V. They work on rotary vane pumps and meet all medical standards for medical equipment.

Pumping units are used as central vacuum systems, that is, they provide vacuum to several consumers or one consumer with a large required pumping speed.

Central vacuum systems

The centralized system simplifies the work of personnel, reduces energy costs and increases the service life of vacuum pumps, while reducing equipment costs.

Centralized vacuum systems are used in cases where there is a multitasking mode and it is necessary to apply vacuum within the same building. Such systems are equipped with centralized controllers and other devices that control the vacuum.

They include the pump and pipelines. Before being used in medical facilities, they must have ABFG antibacterial filters installed. Strong particle filtration prevents the formation and large accumulation of trace elements in the vacuum receiver. One of the best medical systems are DVP TRIPLEX, they work smoothly and have proven themselves all over the world. They have a triple pumping system and a double control system, and have a safety system program.

What is a vacuum station made of?

The standard assembly includes three pumps, a vacuum collector, cleaning filters, a receiver and a control box for access control and operation configuration. This is a convenient and easy-to-use unit, it is easy for medical staff to switch compressors and monitor the performance of the device.

The vacuum station is primarily needed for resuscitation and surgery. The main tasks are:

• ensuring round-the-clock operation of medical equipment: anesthesia machines, ventilators, aspirators;
• stations help to carry out the operation in a timely manner;
• sterility and safety;
• antibacterial effect.

A vacuum station is essentially an auxiliary device attached to a medical vacuum. It distributes the flow in a medical vacuum.

The polluted air that the pump throws out passes through a network of antibacterial filters. In a piston compressor, air is compressed when the pistons move, and its injection is provided by a screw. It is screw compressors that prepare fresh air and smooth it out with the receiver. The air flow must be gentle. The receiver consists of one or more motors.

Its volume can be different, it all depends on the outlet pressure and the compressor. applied to it. Air treatment and how the purification process proceeds are important factors in the choice of equipment and antibacterial filters and a dehumidifier must comply with quality standards and have all certificates. More precisely, pumps decompose gases and various substances, remove them. At the same time, the chambers of the systems are completely sealed, which contributes to the isolation of bacteria. As foreign substances are removed, the volume of the cavities of the device changes, as a result of which the substances pumped by the pump are distributed in the required direction. But it is worth remembering that the principle of operation of vacuum systems also directly depends on the purpose of the vacuum system.

A vacuum system tester is used to test different vacuums. It is also worth mentioning, because the tester measures the degree of rarefaction in vacuums, helps to identify valve malfunctions and the installation of UOZ, measures the performance of vacuum-controlled devices, checks pressure sensors and brake bleeding. Such diagnostic equipment is a mandatory requirement when purchasing medical equipment, since its safety and performance must be checked regularly and systematically.