Russian special forces will receive a two-medium breathing apparatus. What is a rebreather Manual oxygen rebreather

This is an apparatus that purifies the gas used for breathing. The oxygen necessary for breathing continuously flows (is forced) into the gas mixture circuit. The exhaust gas remains in the circuit: it passes through a unidirectional channel and is cleaned of CO2. After cleaning, the gas is again supplied to the inspiratory bag, then the cycle is repeated.

Rebreather: new technology?

Did you know that the first submersible was a rebreather? It was created in 1878 by the engineer Fleuss and consisted of a rubber mask connected to a breathing bag, which was filled with oxygen supplied from a copper cylinder; carbon dioxide was absorbed by a "filter": interwoven fibers impregnated with caustic potash (potassium carbonate). In 1915, Fleuss's idea was borrowed by Sir Robert Davis when creating an apparatus for emergency ascent from submarines, which then began to be produced all over the world. Hans Hass is the first underwater photographer to dive on a rebreather.

ARO - (closed cycle oxygen rebreather) originally from Italy, was created between the 1st and 2nd World Wars. In 1933-34, the Italian military divers Teseo Tesei and Elios Toschi appreciated the indispensability of this device in military operations, some changes were made to the device, and it began to play the first violin in the operations of the fighters of the Gamma and Maiali detachments.

After the war, the ARO was used by the Navy to train divers.

The ARO is still used today for training and diving to very deep depths.

Meanwhile, in 1969, Dra "ger develops very relevant semi-closed cycle nitrox devices and releases the FGT (this device is still used by many military divers).

Later came the FGT III, a semi-closed-cycle heliox, for diving to depths of up to 200 meters.

In the following years, Dra "ger perfected the system to ensure continuous flow and took a leading position in the production of these components.

In 1995, the first semi-closed circuit rebreathers for sports began to be produced.

To date, there are three main types of rebreathers - oxygen, semi-closed and closed devices.

Oxygen rebreathers

This type of apparatus uses pure oxygen and is completely closed. The history of their creation and use dates back to the 19th century. These devices were actively used by Hans Haas and his wife Lota Haas, the most famous underwater explorers and photographers. During the war, these devices were actively used by underwater saboteurs of all countries participating in the war. Currently, oxygen rebreathers have undergone minor changes and are used mainly by the navy. Devices of this type are the most compact, simple in design and reliable. As a rule, they contain one counterlung, one bottle of oxygen and a canister of chemical absorber. Pure oxygen is supplied to the breathing bag through a special nozzle at a certain speed, or periodically. Then you inhale oxygen and exhale already into a canister of soda, where the formed carbon dioxide is absorbed and everything is again in a circle. No electronics, only a pressure gauge. The most famous products of this class are LAR-V of the German company draeger, Oxyng of the French company spirotechnique, Italian products from OMG and of course a large number of Soviet devices - IPSA, IDA-64, IDA-76, IDA-71, etc. .d. The main disadvantage of these devices was and is - the depth limit is 6 meters.

Semi-closed rebreathers

These devices are divided into two types: aSCR - devices with active gas supply and pSCR - with passive supply, respectively.

aSCR- these devices were developed in the fifties and were used, as is usually the case with the military, mainly by sappers divers. The principle of operation is extremely simple. The cylinders are filled with nitrox (mostly), the gas is supplied in a constant stream through a special nozzle (draeger Dolphin, Ray) or through an adjustable needle valve (Azimuth, Ubs-40) into the inhalation bag, then you exhale accordingly into the exhalation bag, then the gas enters chemical absorber canister and back into the inhalation bag. During these procedures, as a rule, an excess of gas occurs, which is removed into the water through a special valve.

aSCR are the most popular recirculation devices on the amateur market today. They are simple, reliable and easy to learn. Their main advantage is gas savings, the use of nitrox mixtures and low noise. On the devices, in the basic configuration, there is no electronics and the recommended operating temperature is from -1 to +35 degrees, which is also an advantage. Disadvantages are depth limitation, lack of advantages in decompression modes and a large difference between the gas in the cylinders and the gas in the breathing circuit, which should be taken into account when planning. The difference is greater, the higher the physical load and can vary from 5 to 20%.

The most famous models Mix-55 , Mixegers 78(France) , Aromix OMG(Italy), Dräger FGT I(Germany) , AKA - 60(Russia). The most famous models for the amateur market are Dräger Dolphin(Germany) , Dräger Ray(Germany) - out of production. Fieno(Japan) - out of production. Azimuth Pro(Italy) , UBS-40(Italy) - are still being produced.

pSCR- differ from aSCR the fact that gas is supplied not through a nozzle, but through a standard regulator in accordance with the diver's minute consumption of the mixture. As a result of direct forced gas addition, the composition of the real respiratory mixture in the passive system circuit is more constant than in devices with active gas supply and does not change significantly with changes in physical activity.

Because the passive type is tied to the RMV value, dive planning is made easier.

The main disadvantage of these devices is the increased inhalation-exhalation resistance, since the breathing bag is located in the lumbar region. (meaning Halcyon devices and its clones - Ron, SF-1, etc.). An interesting development in this direction is the K2-advantage apparatus (it has a breathing bag on its chest).

Devices of this type are not widely used and are not certified in Europe.

closed rebreathers

Subdivided into eCCR and mCCR.

eCCR- this type of apparatus is the most complex, advanced and, accordingly, expensive.

The price of products ranges from 9 to 14 thousand dollars. These are the quietest devices, but their most important advantage is the ability to maintain a constant partial pressure of oxygen, due to this, efficient and fast decompression occurs, and the no-decompression limits increase. As a rule, the device uses two cylinders - one with oxygen, the second with a diluent (air, trimix, heliox). The rebreather uses electronics to monitor the partial pressure of oxygen and to supply oxygen to the circuit as needed through a solenoid valve. In principle, this is all, the devices differ in nuances - the number of oxygen sensors, the location of the breathing bags, the presence of built-in decompression meters, etc. The most famous and popular devices of this type are Inspiration Vision (England), Megalodon (USA). At present, a lot of closed-type electronic devices have appeared on the market - Optima (USA), Sentinel (England), Voyager (Italy), etc. But the leaders remained the same.

Most importantly, eCCRs require a respectful attitude, increased attention and very good training. Closed submersibles require more discipline and responsibility, so their users should be people who dive regularly and are well versed in the specifics of rebreathers. When working with CCR, there is an increased risk of running into hypoxia or hyperoxia.

mCCR- differ from electronic devices in that they do not supply oxygen to the circuit through a solenoid at the command of a computer, but constantly flows through a nozzle (almost like in an SCR or in a simple oxygen apparatus), but it is supplied in a smaller amount than is necessary for the human body, t .e. somewhere around 0.6-0.7 l / min. Electronics is present to keep track of po2 values. Lack of oxygen is supplied manually. As it usually happens in our country, we don’t keep what we have, we will lose it by crying. Foreigners took our IDA-71 and made mCCR out of them. Today, the most popular devices of this type are - KISS (Canada), rEVO (Belgium), Submatix (Germany), Pelagian (Thailand).

Prices range from 5 to 8 thousand dollars.

The device complies with the requirements of GOST R 53256-2009. Self-contained closed-cycle breathing apparatus operating on compressed oxygen with excessive mask pressure is designed to protect the respiratory organs and human vision during long-term use in a smoky or toxic gas environment. It is used in rescue work in mines, on fires, in confined spaces, during rescue work in tunnels and work with harmful substances.

All modifications of the AP "Alpha" are made in the form of a knapsack, the load from which, when worn, is distributed on the shoulders and hips. The unit is equipped with a pressure gauge that indicates the amount of oxygen remaining and produces two visual alarms and one audible alarm to indicate the status of the system.

The closed loop system recycles exhaled air, removes carbon dioxide, replaces consumed oxygen, absorbs condensate, and cools the inhaled and exhaled air.

Overpressure provides an internal pressure under the mask slightly above the external atmospheric pressure. This provides 100% protection of the respiratory and vision organs from the ingress of the external atmosphere under the mask.

Growing popularity.

Modern open-circuit breathing apparatus, or conventional scuba, began to be actively used after 1943, when they were invented by Jacques-Yves Cousteau and Emile Galliano. Closed cycle devices remained unclaimed for a long time.

In 1987, within the framework of the Wakulla springs project, led by Dr. William Stone, while studying a cave system 5 km long, the CisLunar Mark I was tested - a closed-type apparatus that demonstrated certain advantages over scuba gear. Since that time, interest in this type of breathing apparatus began to increase.

Rebreathers and their main types
Closed-circuit breathing apparatus is usually called rebreathers, from the English word "rebreather", that is, "rebreather". The exhausted respiratory gas in them is not discharged into the water, but, freed from carbon dioxide, enriched with oxygen, then re-supplied for breathing. Therefore, rebreathers are more complicated than scuba gear.

In addition to the hose connecting the cylinder to the mouthpiece, there is a second one for returning the used mixture to the circuit. A semi-rigid or soft bag with a water trap is required to receive the exhaled mixture, the pressure of which must be equal to the external water pressure. Next, the mixture is fed into a canister, in which carbon dioxide is removed from it by a chemical absorber. The subsequent addition of oxygen is carried out in each type of apparatus in its own way.

The main criterion for the classification of rebreathers is the degree of closedness of the respiratory cycle. There are devices of a completely closed cycle, or CCR-rebreathers, in which the exhaled mixture is completely recycled. The gas in them is discharged into the water, but only upon ascent, through the etching valve. The decreasing pressure causes the mixture to expand, so its excess is removed.

Semi-closed devices, called SCR rebreathers, use artificial breathing mixtures (Trimix, Nitrox, Heliox) rather than pure oxygen, so the resulting excess nitrogen and helium must be periodically removed from the breathing circuit.

Closed circuit rebreathers

The design of a pure oxygen rebreather is the simplest and lightest; the device does not leave bubbles in the water, which is why it is popular with biologists and the military. However, the use of oxygen alone introduces limitations. With increasing pressure, it becomes toxic, negatively affecting the respiratory and nervous systems. In this regard, the depth for diving should not exceed 7-10 m. Oxygen, moreover, contributes to the rapid development of caries.

One of the varieties of oxygen rebreather is an apparatus with chemical regeneration of the breathing mixture. In the absorption canister, a volume of oxygen is released that is equal to the absorbed carbon dioxide, which allows you to stay under water for a record amount of time - up to 6 hours. Due to the danger of the regenerating substance, which releases alkali when water enters it, such devices are almost never used.

There are rebreathers that allow you to work with artificial mixtures for breathing, which allows you to dive to fairly great depths. Some devices use an electronic control system for the supply of oxygen to the breathing circuit, the weak point of which is electrochemical sensors that require regular replacement, and a solenoid valve. Famous representatives - CIS Lunar, Buddy Inspiration. In others, the control is semi-automatic, where the supply of oxygen is controlled by the diver.

Semi-closed rebreathers

The difference in the design of semi-closed circuit rebreathers lies in how the breathing mixture is delivered. In devices with active supply, when the valve on the cylinder is opened, the breathing mixture is continuously fed into the breathing circuit through a nozzle with a throughput that varies with depth and with the mixture used. Such rebreathers are simple in design and maintenance, it is easy to calculate a dive plan with them, since the mixture flow rate at any depth is approximately the same. Perhaps that is why they have gained the greatest popularity among other types of rebreathers. Well-known devices of this type are Ray and Dräger Dolphin, Atlantis and Azimuth.

In devices with a passive mixture supply, the amount of removed and incoming gas is not regulated depending on pressure, that is, on depth, therefore, it is necessary to calculate the flow rate of the gas mixture as for ordinary scuba gear. But a rebreather, unlike scuba gear, has several times more time left under water, since not the entire volume of exhaled gas is vented in it, but from about 10 to 30 percent. Well-known devices of this type are the Halcyon RB-80 (analogue is the European RB2000).

Rebreather or scuba?

Rebreathers outperform conventional scuba with less noise and fewer bubbles, unchanged buoyancy during inhalation and exhalation, since the volume of the mixture does not decrease, or almost does not decrease on exhalation. The absorption of carbon dioxide results in the release of moisture and heat, which makes the air the diver breathes more pleasant, which increases resistance to decompression sickness. In addition, the time spent under water with a rebreather increases, and the delivery of gas mixtures to the dive site by reducing their required volume does not cause so much trouble. Closed cycle rebreathers on mixtures allow reaching greater depths than the threshold 40 m for other devices.

Why didn't rebreathers replace conventional scuba gear? They have their shortcomings. These submersibles are more expensive, more difficult to maintain, heavier and larger, inconvenient for use by two divers in critical situations, and require the provision of consumables such as an absorber and various sensors. In addition, the rebreather is more convenient to use in a team.

As you can see, the advantages of each type of breathing apparatus are balanced by its disadvantages, so both rebreathers and scuba gear are worthy of being used. When choosing, you should clearly know what the device will be used for, what type of devices are used in the team. The choice in favor of a rebreather will not make you disappointed in it. It is not in vain that they are beginning to gain popularity in Russia lately.

according to the site aqua-globus.ru

A rebreather is a recirculating breathing apparatus, that is, such an apparatus, in which, unlike scuba (SCUBA), when exhaling, the respiratory mixture is not removed into the water at all or is not completely removed. Instead, the spent mixture is processed so that it can be re-breathed (re-breathe - re-breathing). For this you need remove carbon dioxide from mixture(carbon dioxide) and add oxygen to the mixture.
The first task is solved in all rebreathers in the same way - they always include a container (absorption canister) included in the breathing circuit, which is filled with a chemical substance that actively absorbs carbon dioxide.
The second task - adding oxygen to the mixture - is solved in different types of rebreathers in different ways. Let's take a closer look at this...

What are rebreathers?

All rebreathers according to the principle of operation can be divided into two large groups: semi-closed and fully enclosed.
AT closed rebreathers (CCR - Closed Circuit Rebreathers), the exhaled mixture is completely recycled and, after removing carbon dioxide, pure oxygen is added to it. This is not to say that the mixture in these types of rebreathers does not etch into the water at all, rather it does not etch when swimming at a constant depth. When ascending, that is, when the external pressure decreases, the breathing mixture expands and its excess is removed into the water through the evacuation valve.
semi-enclosed rebreathers (SCR - Semi Closed Rebreathers) differ from closed ones in that the mixture is removed from the breathing circuit even when swimming at a constant depth, but the amount of mixture removed is much less than that of conventional scuba. Removing part of the mixture is necessary because to maintain the required level of oxygen in the breathing mixture, not pure oxygen is used here, but artificial breathing mixtures such as Nitrox, Trimix and Heliox. Therefore, it is necessary to remove the excess of neutral gases: nitrogen and helium.
In turn, both closed and semi-closed rebreathers can be of several types according to the principle that maintains the optimal composition of the respiratory mixture.
closed:
1) Oxygen rebreathers(CCOR - Closed Circuit Oxygen Rebreather) operate on pure oxygen, i.e. the diver breathes pure oxygen without admixture of any neutral gases. This principle simplifies the design and reduces the size, but also introduces its limitations. You and I know that oxygen becomes toxic when the partial pressure increases above 0.5 bar. In this case, toxicity manifests itself in two forms: pulmonary (calculated in OTU - Oxygen Tolerance Units) and convulsive (calculated by the effect on the central nervous system CNS - Central Nervous System). The maximum safe partial pressure of oxygen for divers is considered to be 1.6 bar (usually 1.4 for long exposures) and only in emergency cases is it allowed to be briefly increased to 2.0 bar (3.0 in the French and Russian Navy). Given the fact that there is still some neutral gas in the breathing circuit of the device, the maximum diving depth in such devices is limited to 7 meters (10 meters in emergency cases).
Another negative factor in the action of pure oxygen is that it "feeds" any manifestations of caries or other diseases of the oral cavity. Therefore, when using such devices, do not forget to visit the dentist regularly (which, by the way, is recommended for all divers) and you will not have problems with your teeth.
Due to their small size, high autonomy and, most importantly, the absence of exhaled bubbles, such devices are very popular with military and underwater biologists.
The most famous representatives of this type are Dräger LAR VI and OMG Castoro C-96.
2) Oxygen rebreathers with chemical rebreather(CCCR - Closed Circuit Chemical Rebreather). Similar in design to the rebreathers of the previous type, but differ in the principle of resuming the oxygen content in the mixture. The fact is that, unlike the absorbing substance, which simply absorbs carbon dioxide, a regenerating substance is charged into the canisters of such devices, which, when absorbing 1 liter of carbon dioxide, releases approximately 1 liter of oxygen.
With small sizes, such devices have fantastic autonomy. For example, when using a typical representative of this group of the Soviet apparatus IDA-71, it was possible to swim under water for 6 !!! hours.
Unfortunately, the regenerative substance is very tricky to use. When water enters the absorbing canister, a foamy alkali is released, resulting in the same "caustic cocktail" that frightens divers when talking about rebreathers (this is one of the most common myths). This "cocktail" can severely damage the mouth, larynx, trachea, and even lungs of a diver. The usual absorbent substance behaves much calmer. Yes, alkali is released when wet, but without a violent reaction, you can determine the flow of water without tasting the mixture, but simply by difficulty breathing.
This type of apparatus was used only by the military, and then only by two countries - the USSR and France. Now, due to the complexity of handling regenerative substances, this type of apparatus is becoming a thing of the past.
3) Electronic gas rebreathers(CCMGR - Closed Circuit Mixed Gas Rebreather). As the name implies, this type of rebreather has an electronic control system that includes an oxygen partial pressure sensor, an electronic circuit that analyzes the oxygen content of the mixture and signals an electric valve to add pure oxygen to the breathing circuit to the optimum level. The advantages of such a scheme are clear: the ability to work with gas mixtures (rather than pure oxygen) and, as a result, dive to almost any depth, always the optimal partial pressure of oxygen at any depth, the absence of bubbles when swimming, the maximum possible saving of the breathing mixture and greater autonomy. On the other hand, it is a complex design with the possibility of electronic failure, complex and expensive to maintain. Sensors operating on the electrochemical principle have a limited service life at a high price and require replacement, as a rule, at least once a year.
The most famous representatives of the type: Buddy Inspiration, CIS Lunar.
4) Gas rebreathers with semi-automatic control(KISS rebreather). They differ from the previous type in that the sensors and electronic circuitry only monitor the partial pressure of oxygen, and the diver himself adds oxygen to the breathing circuit if necessary.
The most intelligent scheme of this type of apparatus provides for the automatic constant supply of oxygen through the nozzle in quantities less than necessary for the diver, and the diver adds oxygen only to maintain the optimal level of partial pressure. In this case, the number of manual manipulations with the device is greatly reduced on the one hand, and on the other hand, one of the points of failure - the solenoid valve - is missing.
Semi-closed:
1) With active supply of breathing gas(CMF SCR - Constant Mass Flow Semi Closed Rebreathers). In these devices, when the valve of the cylinder containing the respiratory mixture is opened, it begins to be continuously supplied through the calibrated nozzle into the breathing circuit. The partial pressure of oxygen is maintained by removing exactly the same (!!!) amount of the spent mixture into water. The fresh mixture supply rate (liters per minute) depends on the throughput of the nozzle and is selected depending on the depth of immersion and the composition of the breathing mixture.
Attractive features in the use of this type of rebreathers are the simplicity of design, ease of calculation, and maintenance. The duration of the dive (according to the reserves of the breathing mixture) practically does not depend on the depth, because at all depths the consumption of the mixture from the cylinder changes very slightly, on the other hand, the partial pressure of oxygen in the breathing circuit is very strong (even more than that of a conventional scuba!!!) depends on two factors: the depth of the dive and the diver's motor activity (i.e. oxygen consumption).
The most famous representatives of the type: Draeger Dolphin and Ray, OMG Azimuth.
2) With passive supply of breathing gas(PA SCR - Passive Addition Semi Closed Rebreather). In this type of rebreathers, the partial pressure of oxygen is also maintained by etching a part of the spent mixture into water, but (!!!) the amount of the mixture clearly established by the design is removed from the breathing circuit with each exhalation (usually from 8 to 25% of the exhaled volume). An equal amount of fresh breathing mixture is supplied instead of the one removed from the balloon. It is known that the respiratory rate is directly related to the diver's oxygen consumption, so the partial pressure in the breathing circuit of such devices is practically independent of oxygen consumption and depends only on the diving depth (as in conventional scuba gear). In simple terms, it can be said that when swimming with this type of rebreather, the diver uses all the calculations associated with the use of gas mixtures in ordinary scuba, but has a gas supply 4-10 times (depending on the bleed coefficient) exceeding the actual volume of the cylinder.
The most famous representatives of the type: Halcyon RB-80, K-2 Advantage, DC-55.

How are rebreathers arranged?

All rebreathers, without exception, are more complex than scuba gear. This is understandable, since the principle of their work is more complicated. Nevertheless, they all have similar design features that make their work possible.
Firstly, unlike scuba, where one hose from the cylinder to the mouthpiece has long been the norm, the rebreather uses two hoses- one for supplying the mixture to the mouthpiece, the other for returning the mixture to the breathing circuit.
Since the respiratory mixture is not exhaled into the water, but returned, a container is needed in which it can be returned. In addition, the breathing gas in this container must be at the same pressure as the surrounding water. Therefore, each rebreather has one or two breathing bags(breathing bag) from which the diver inhales and exhales the gas mixture at a pressure equal to the ambient pressure. Bags can be soft or semi-rigid (on semi-closed passive rebreathers).
To clean the mixture from carbon dioxide, all rebreathers have canister in which falls asleep chemical absorber.
As mentioned above, the absorbent does not like water to get into the canister. Therefore, most rebreathers are designed with water traps or hydrophobic membranes. The purpose of such devices is to intercept the water that has entered through the mouthpiece and prevent it from entering the absorber. Usually, a second counterlung (expiration bag) is used as traps, which also allows you to reduce the exhalation resistance of the rebreather.

Advantages of rebreathers.

Speaking about the benefits, we need to start with another myth that rebreathers are cheaper to use than scuba tanks, because they consume less breathing gas... This is true, but provided that helium-based mixtures (!!!) are used, which is expensive. When using the relatively cheap Nitrox, the savings in mixture consumption can even be offset by the cost of the scavenger. In addition, for complex types of rebreathers such as electronically controlled closed apparatus, one must take into account the need to replace sensors, which are also not cheap and provide a superficial support team in case of unforeseen circumstances !!!
Another myth is that rebreathers allow you to swim so long and so deep that it is unattainable with ordinary scuba gear. This is also true, but not all types of rebreathers are suitable for this rule, but only rebreathers of a closed cycle working on mixtures! All other types of rebreathers do not fall under this definition...
Now for the real benefits:
1) Less noise and fewer bubbles, which usually scare away all cautious marine life;
2) Almost unchanged buoyancy during the inhalation-exhalation cycle. Since the total volume of the breathing mixture in the lung-rebreather system remains almost unchanged, the diver does not pull up when inhaling, and does not put down when exhaling. A very valuable feature for underwater photographers and videographers, isn't it?;
3) When carbon dioxide is absorbed, a certain amount of water vapor and heat is released, so the diver breathes warm and humidified air. This improves comfort and reduces the risk of decompression sickness, especially when swimming in cold water. For the same reason, rebreathers do not free-flow.
4) When organizing serious expeditions that require the use of gas mixtures, much fewer gas cylinders have to be delivered to the dive site. Although, as described above, you are unlikely to win in cost, rebreathers use significantly less gas mixtures than scuba tanks, so a rebreather expedition will indeed require less gases.

Disadvantages of rebreathers.

Let's start with the myths again. We have already spoken about the caustic cocktail above, as well as about ways to combat this phenomenon. It remains only to note that it is very difficult to obtain such a cocktail in modern rebreathers, even if you specifically try. Even when the mouthpiece is released from the mouth, it floats up due to the positive buoyancy of the hoses and begins to bleed the mixture from the inhalation bag, so the amount of water that enters the exhalation bag is negligible.
Difficulty of learning. Partly true, at least with respect to closed rebreathers on mixtures. Training for all other types of rebreathers certainly assumes the basic knowledge of the student, but is no more difficult than any of the scuba diving courses.
Service complexity. Yes, maintenance of any rebreather takes more effort and time than scuba gear, but the procedures are standard and do not cause difficulties. It just takes getting used to, just like with the SCUBA.
The most important myth is that buying a rebreather will cost much more than a scuba. Indeed, most rebreathers are more expensive than the average SCUBA kit, but some models, especially semi-closed rebreathers with active supply, are quite comparable in price to a good SCUBA kit.
Now let's move on to the real disadvantages:
1) A rebreather is not an apparatus of individualists, it requires training and teamwork much more than scuba gear. However, should this be considered a disadvantage?
2) The difficulty of using one apparatus by two divers in an emergency. Although some divers are now practicing this exercise, the most commonly used is the emergency diver's open circuit breathing from a separate bailout or rebreather gas cylinder.
3) The greater weight and dimensions of the apparatus itself (not including cylinders) - the difficulty when traveling.
4) The need to provide consumables (gas mixtures and absorber) at the dive site. Although the gas mixtures used are mostly standard, the absorber will appear when rebreathers become common in our reservoirs.

Considering technical diving
as the pinnacle of scuba diving,
then rebreathers are just a complete flight into space!

Few people know that rebreathers or rebreathers came to us much earlier than ordinary scuba, for this you just need to look into the history of the invention of the rebreather, and yet, only in our time, technological progress has helped to make these dives on closed-loop systems universally available to the diving community, and not just to professionals from specialized military and scientific organizations.

You are tired of the roar of exhaled air, and a pile of heavy iron with the outlines of hanging cylinders does not look as aesthetically pleasing as the first time, and of course you have long wanted to optimize your decompression mode, then the way to rebreathers is your way!

as follows:

It is considered the most successful and therefore the most common rebreather of a semi-closed cycle with a passive supply of a respiratory mixture.

Developed by the German company Draeger and is a modification of the earlier model Atlantis I. This model is easy to operate and reliable in use.

Using standard nitrox mixtures, it allows you to dive up to a depth of 40 meters. There is a trimix modification that increases the allowed depth to 80m.

Training to work with this device takes 2-3 days. Four dives in open water allow you to fully work out the necessary exercises and get a complete understanding of the specifics of diving in a rebreather. We highly recommend this course as a preliminary to the Inspiration course.

This is the world's first mixed closed rebreather, mass-produced. In addition, Inspiration is the first and currently the only device in its class to be certified by the European Standards Agency. This certificate authorizes the safe use of the apparatus at depths up to 50 meters with air as a diluent and at least 100 meters with trimix mixtures.

gives us the opportunity to use all the advantages of nitrox mixtures, and at 100%. The control unit automatically maintains a constant partial pressure of oxygen in the breathing circuit, regardless of depth, constantly changing the percentage composition of the mixture accordingly. In other words, the apparatus provides the optimal breathing mixture (best mix) at any depth during the entire dive, up to the supply of pure oxygen at the last decompression stops.

This means unparalleled versatility: a deep-water wreck or a shallow offshore reef, it doesn't matter, a standardly prepared unit will provide you with the optimum mix at any depth. It allows you to fully realize all the advantages of the best mix, such as expanding the NDL, minimizing decompression modes, etc., but without the dreary preliminary planning associated with the selection of a gas mixture depending on the specific depth of the dive, calculating the gas supply, choosing the equipment configuration , stage cylinders, etc. Plus, you don't have to switch from mix to mix underwater.

Diving with Inspiration is all about making the most of your gases. This efficiency is especially pronounced at considerable depths, where the consumption of the gas mixture in systems operating according to the open breathing scheme becomes catastrophic. Hence the high popularity of the rebreather among technical divers.

Along with the advantages already listed, we should also note such positive qualities as minimizing the cost of expensive helium, the compactness of the apparatus, the ease of buoyancy regulation, breathing with warm humidified gas, and, finally, the complete absence of exhaled bubbles, which makes diving comfortable, quiet and not causing stress for underwater inhabitants.

Inspiration has revolutionized diving. Being the first mass-produced device of this class and, most importantly, affordable, it is widely sold in more than 40 countries around the world. Having passed rigorous tests in specialized organizations in the UK and the USA, the device is manufactured in strict accordance with quality standards and requirements, its service and factory supply of spare parts is provided.

- The exhaled gas is directed by a non-return valve through the hose to the exhalation bag. This is where the cycle starts.
- Then the gas, freed from possible residual water, enters the absorber cartridge. Here it enters into a chemical reaction with an absorbent (Sofnolime), where it is released from carbon dioxide.
- In the mixing zone at the top of the cartridge, there are three independent oxygen sensors that measure the partial pressure of oxygen in the mixture, allowing the electronic regulator to maintain the set PO2 value with high accuracy by injecting additional pure oxygen from the cylinder as it is consumed by the body.
- The purified and oxygenated mixture passes through the hose into the inhalation bag, and then through the valve box to the mouthpiece. The cycle is complete.

Diluent

Inspiration has two 3 liter bottles. One cylinder contains pure oxygen, the other contains the so-called diluent - a diluent gas. Up to depths of 50 m, this is usually air; deeper, it is trimix or heliox. The diluent has several functions:

Manually or through a lung machine (if installed), the diluent is fed into the breathing circuit to compensate for the pressure increasing with increasing depth and to prevent the "collapse" of the bags.

It is also used for BCD inflation and drysuit. Diluent consumption is extremely low, about 30 - 40 bar for the entire dive.

As a diluent, it is the main component of the respiratory gas mixture, maintaining it within safe limits from the point of view of oxygen poisoning.

One of the most important functions of a diluent is its ability to be used as a reserve supply for circuit ventilation or to switch to open circuit breathing in an emergency.