Breathing apparatus with compressed air: device, classification, maintenance and scope

A person needs air to function. It contains vital oxygen and nitrogen. But sometimes a situation may arise when it is impossible to access the familiar air. This problem is relevant for divers, firefighters and many others. And in these cases, breathing apparatus with compressed air comes to the rescue. What are they? What diversity do they have? How to look after them? These, as well as a number of other questions, will be answered in the framework of this article.

general information

And you should start with the terminology. So, breathing apparatus with compressed air (also known as DASV) is an insulating reservoir device, which provides the ability to store the substances necessary for the functioning of the human body. As a rule, a cylinder is selected for this. The air in it is stored in a compressed state. DASWs work according to an open breathing pattern. In other words, inhalation is carried out from the cylinder, and exhalation is carried out into the surrounding atmosphere. What do compressed air breathing apparatuses look like in general? The scheme of their device usually assumes the presence of:

1. Cylinder with valve.
2. Hanging system.
3. Gearboxes with safety valve.
4. A lung machine with an air hose.
5. Sound alarm device.
6. Exhalation valve.
7. Additional air supply devices.
8. Pressure gauge.
9. Front part with intercom.

Also can additionally be attached:

1. The union that is used for fast refueling of cylinders.
2. Rescue device connected to a breathing apparatus.
3. Quick-connect connection for connecting a rescue device or ventilation equipment.

When trying to classify the DASW, the question immediately arises of what to choose as a reference point. So, if you look at the design, there will be one thing, the purpose is quite another. Also relevant are questions about air consumption, its reserves and much more. Therefore, in order not to stray in the future among the three pines, let's deal with all species diversity.

Classification of breathing apparatus

With compressed air it is not necessary. If we consider the design, then they are created:

1. With an open circuit. It is to them that the considered breathing apparatus with compressed air belongs.
2. Closed loop. They operate on compressed, liquefied, or generated oxygen. Quite poorly distributed due to complex maintenance, as well as high fire hazard.

In addition, the classification is still based on the principle of their action: non / autonomous. If we talk about application in difficult conditions (for example, for firefighters), then such devices belong to the second type. And this is not surprising - who knows where to climb.

In addition, there are pulmonary machines with excessive air pressure under the front of the device and without it. These devices are more focused on people who have to work in high temperatures. For example, firefighters. In this case, overpressure is necessary in order to protect a person from a smoky and toxic gas environment during fire fighting. After all, they fulfill their duties in extreme conditions, in which staying without special breathing apparatus is guaranteed to get health problems or can even be fatal. Structurally, they are an isolated gas mask that does not involve the use of ambient air.

Design Interaction: Verification

Respiratory protection in case of fire or deep diving is a priority. And in this case, it is extremely important that everything works without problems. Therefore, the design must be carefully and carefully checked. A list of what is included in it has already been submitted. Now let's look at the purpose of each component and why it is necessary to check the breathing apparatus with compressed air:

1. The front part - allows you to protect human organs and provides the usual working conditions for the whole organism.
2. One / two / three cylinders are needed for storing compressed air. So that he does not get lost, they are equipped with a shut-off valve.
3. A flexible hose system provides air to the breathing zone.
4. A pressure gauge is needed to determine residues.
5. The signaling mechanism warns of an imminent stoppage of work and that the danger zone should be left.
6. The cylinder is charged thanks to high-pressure compressors, which are equipped with a filtering system and drying of ambient air.

For the operational preparation of equipment in the middle of the work process and further activities, additional rescue devices can be used. Their mission is to quickly restore air supplies. If everything is done correctly, then comfortable breathing conditions will be created for a person in which supplies will be spent economically, and there will also be no third-party chemical components. When inspecting the structure, attention must be paid to the signaling mechanism - it is necessary to ensure that it works without problems. All this will save your life from possible problems.

However, it should be noted that all these devices have a significant mass and dimensions, as well as cylinders that require periodic recharging.

And a bit about gas masks

For most people, this topic applies exclusively to civil defense. Well, it should be noted that gas masks have a much wider use than they are accustomed to attribute to. And this is not surprising, because almost no attention is paid to other aspects. For example, many find it difficult to imagine what an isolated gas mask is. He relates to a greater extent exclusively to firefighters. An insulating gas mask allows you to maintain high mobility, while protecting against harmful gases. It is no secret that the overwhelming majority of those killed in fires before being burned get carbon monoxide poisoning and lose consciousness.

The insulating gas mask works on the principle of scuba gear. It should be noted that in it compressed air is under extremely high pressure. If the valve bursts, then if it enters a person, he will be seriously injured, possibly not even compatible with life. Since these devices are small, the working time with them is 30-40 minutes. Usually this is more than enough. But still, firefighters often carry several supplies with them.

By the way, gas masks can work not only with air, but also with oxygen. In this case, their shelf life can reach four hours. This their advantage is used when working in mines, subways and other similar structures. But there is one significant minus - the teeth deteriorate very quickly. If you constantly work in such an apparatus, then they will crumble as if made of gypsum. Therefore, an oxygen isolating gas mask is used quite rarely. Again exclusively in adverse conditions when other devices are not suitable. That is, initially the calculation of the air supply and the assessment of the necessary actions can take place, and then make the appropriate choice.

The nuances of work

The pressure under which the air is in the cylinder is estimated at 300 atmospheres by default. In the future, this indicator is affected by the frequency and depth of inspiration. It is on this that the internal pressure and time of the activity with protection depends. For many, the question may arise: if work in breathing apparatus with compressed air proceeds under such conditions, then how does a person not flatten inside a mask? This fact has a very simple explanation: the thing is that when he goes through the hoses, he has to go through a special gearbox. It sprays air in a thin (but powerful) stream, creating pressure in the mask in two atmospheres. If the gearbox fails, then the air will not smear the person, but simply will stop its flow.

It should also be noted caution in working with rooms in which there are toxic and dangerous gas mixtures. Let's look at one important example. Films often show how a lone fireman rushes ahead to pull someone out. In reality, this is contrary to safety precautions. If firefighters enter a hazardous room, then their link should consist of at least three people (two, if more, due to certain reasons, is impossible). Also, according to safety precautions, one person should always stand outside. He calculates the remaining time for the link, estimates when they should go and the like.

It should be noted that this moment is often ignored, and in practice, everyone who has respiratory protection in case of fire, go inside the object.

What is the difference between different devices?

Since respiratory protection in a fire or chemical accident for rescuers received the main distribution, we will consider this issue from already known positions. What is their difference? Suppose a fireman needs an answer. So, if you try to dive under water with its respiratory protection kit, then water will put pressure on the gearbox valve. The deeper - the stronger.

It is believed that it is safe to dive three meters. Further there will be problems with the valve of the gearbox - it will not open, because of which air will not go.

But to stay in space, having only a cylinder with compressed air like firefighters, it is quite possible. True, high-quality sealing is not provided, and the air supply is limited - therefore, it is not recommended for this purpose.

What are they similar?

Initially, a rather high price should be noted. A quality kit costs in the range from 40 to 80 thousand rubles, although relatively cheap devices are sold, the task of which is to give a small gain in time for people who do not take risks on an ongoing basis.

Also common is the situation when the device itself is assigned to several people. But the mask is only for one person. This is done for sanitary reasons - suddenly someone has a cold sore.

It should be noted, and quite significant weight, which is measured in kilograms. After several hours of movement, back pain occurs in them.

The principle of operation in devices is one. The numerical parameters vary, which can affect both the timing and the size of the device. So, a cylinder with compressed air can be designed for 10-15 minutes, and for several hours.

We will take the time for the representative of these remedies

Until now, we have considered conditionally generalized apparatuses. Now let's look at specific representatives.

You can start with AP-2000 (Breathing apparatus). It is designed to protect vision and respiratory organs from exposure to hazardous smoke and toxic environments during fire fighting and liquidation of accidents. It can also be used to evacuate an injured person from a danger zone in which there is an environment unsuitable for breathing.

AP-2000 is an insulating tank apparatus. The air supply is kept compressed in cylinders. In this case, the operating pressure ranges from 1 MPa to 29.4 MPa, or, in other words, from 10 kgf / cm ² to 300 kgf / cm ² . A full-fledged panoramic mask of the device allows you to maintain excess pressure for pulmonary ventilation. This indicator can reach a value of 85 liters per minute.

The operating temperature range is from -40 to +60 degrees Celsius. Overpressure in the submask space at zero air flow rate is maintained at 300 ± 100 Pascals, which for clarity is equivalent to 30 ± 10 millimeters of a water column or 0.225 mercury.

The severity of the work performed, as well as the temperature, affects the duration of the protective action. So, for example, when spending 30 l / min and 25 degrees Celsius, you can perform actions of 60-80 minutes in the device (depending on the specific configuration). Whereas at minus 40 this indicator will be equal to only 45-60.

It should be noted that this is not the best copy that is on the market. For example, there is a breathing apparatus with compressed air AP "Omega", which is built taking into account the wishes of those people who operated the AP-2000. It has increased security, comfort, as well as some additional features. Let's look at it in more detail.

What is the structure of the breathing apparatus of Omega?

It is made of such parts:

1. Suspension system and lightweight panel. Made of composite materials, comfortable, have an ergonomic surface profile to provide maximum comfort for the user. The suspension system provides for the presence of soft shoulder straps and a comfortable belt.
2. Hoses They have high frost, oil and gas resistance, are highly durable, and can also withstand the effects of surfactants. Hoses are designed in such a way as to exclude the possibility of breakage during operation, and also provide maximum safety during vigorous activity. Hoses have tees that are equipped with two quick couplings. They are used for the main mask, as well as for the rescue device.
3. Pulmonary automatic machine AP-98-7KM. This miniature servo-driven device is made of high-strength plastic. It has a bypass, as well as an overpressure shutdown button. It is mounted on the side of the mask, so it does not interfere with the tilt of the head. To enable / disable bypass, you only need to rotate the handwheel on the housing, which allows you to quickly and practically without taking any hands to make manipulations.
4. Pulmonary automatic machine AP-2000. Made of high strength polycarbonate. The case has a multi-function button for turning on the additional air supply / turning off the overpressure (it is also a bypass).
5. Pulmonary automatic machine AP "Delta". A small design that does not interfere with tilting and turning the head. There are two options for bypass operation. It can work on the machine or in manual mode.

What else?

We reviewed the first part of the list. The second is as follows:

1. Mask PM-2000. Designed specifically for the AP series breathing apparatus. Among the advantages, it is worth recalling the increased ergonomics and quality of the material used.
2. Mask "Delta". It was developed by order of the Ministry of Emergencies of the Russian Federation. Suitable for any type of compressed air breathing apparatus that has excess pressure in the submask space. It has a low resistance to inhalation and exhalation. The design allows the air stream to uniformly blow around the sight glass, which eliminates its freezing and fogging. This allows you to use the mask for a wide range of temperatures - from -50 to +60 degrees Celsius. You can also install a communication device in it.
3. Mask "PANA FORCE". It is panoramic. Lateral connection of the pulmonary machine is provided. It is possible to use together with the welding shield.
4. Alarm device with pressure gauge. Located on the shoulder strap and has a rotating connection.
5. Gearbox. A simple and reliable device for which an integrated valve is provided. It provides stable reduced pressure for the entire service life of the device. Additional adjustments during operation are not needed.
6. High pressure cylinders and valves. As part of the apparatus, two types of tanks are used: steel (Russia or Italy) and metal composite (Russia or the USA). For valves, a vertical and horizontal arrangement of the flywheel is provided. There are several options for their execution: with a shut-off valve (prevents the occurrence of a jet stream when breaking off); with a membrane-type safety device (protects the cylinder from explosion when the pressure rises when the cylinder is heated, and the like); both variants.

About maintenance, put in a word

That's practically considered breathing apparatus with compressed air. It remains only to pay attention to how to care for these devices.Indeed, timely maintenance of breathing apparatus with compressed air is the key to their constant availability and high reliability during operation. Which, accordingly, allows to ensure safety for life and health. In order for the devices to function well, it is necessary to perform a certain set of organizational and technical measures and work. Depending on their purpose and nature, two groups are distinguished:

1. Maintenance system. It includes work that is aimed at maintaining the device in a usable condition.
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3. Disinfection, replacement of regenerative cartridges, oxygen cylinders and the like.

All these actions allow you to keep the devices with compressed air ready for use.