BREATHING APPARATUS WITH COMPRESSED OXYGEN (DASK)
General device and principle of operation of DASK
Compressed oxygen breathing apparatus (CASC) is a regenerative apparatus in which a gas respiratory mixture is created by regenerating the exhaled gas mixture by absorbing carbon dioxide from it by a chemical substance and adding oxygen from a small-capacity cylinder present in the apparatus, after which the regenerated gas respiratory mixture enters the inhale.
DASC should be efficient in breathing modes characterized by the performance of loads: from relative rest (pulmonary ventilation 12.5 dm 3 /min) to very hard work (pulmonary ventilation 85-100 dm 3 /min) at an ambient temperature of -40 to + 60 °C, and also remain operational after being in an environment with a temperature of 200 ± 20 °C for 60 ± 5 s.
Rice. 2.1.
Nominal protective action time (hereinafter referred to as RTA) is the period during which the protective ability of the apparatus is maintained when tested on a human external respiration simulator in the mode of performing work of moderate severity (pulmonary ventilation 30 dm 3 /min) and ambient temperature (25 ± 2) °C. In the mode of performing work of medium severity (pulmonary ventilation 30 dm 3 /min) at an ambient temperature of (25 ± 1) ° C, the HVD DASC for firefighters should be at least 4 hours.
The actual time of the protective action is the period during which the protective ability of the device is maintained when tested on a human external respiration simulator in the mode: from moderate work to very hard work (pulmonary ventilation 85 dm 3 /min) at an ambient temperature of -40 °С to +60 °С.
Modern DASC (Fig. 2.2) consists of air and oxygen supply systems. The air duct system includes a front part 7, a moisture collector 2, breathing hoses 3 and 4, breathing valves 5 and 6, regenerative cartridge 7, cooler 8, breathing bag 9 and overflow valve 10. The oxygen supply system includes a control device (pressure gauge) 77, showing the supply of oxygen in the apparatus, devices for additional (bypass) 12 and main oxygen supply 13, locking device 14 and oxygen storage tank 15.
with compressed oxygen
The front part, which is used as a mask, serves to connect the airway system of the device to the human respiratory system. The airway system, together with the lungs, forms a single closed system isolated from the environment. In this closed system, when breathing, a certain volume of air makes a variable movement in direction between the lungs and the breathing bag. Thanks to the valves, this movement takes place in a closed circulation circuit: the exhaled air passes into the breathing bag along the exhalation branch (front part 7, exhalation hose 3, exhalation valve 5, regenerative cartridge 7), and the inhaled air returns to the lungs along the inspiratory branch (refrigerator 8, inhalation valve 6, inhalation hose 4, front part 7). This pattern of air movement is called circular.
Exhaled air is regenerated in the airway system, i.e. restoration of the gas composition that the inhaled air had before entering the lungs. The regeneration process consists of two phases: cleaning the exhaled air from excess carbon dioxide and adding oxygen to it.
The first phase of air regeneration takes place in the regenerative cartridge. As a result of the chemisorption reaction, the exhaled air is cleaned in the regenerative cartridge from excess carbon dioxide by the sorbent. Two types of carbon dioxide chemisorbents from exhaled air are used in DASC: calcareous based on calcium hydroxide Ca(OH) 2 and alkaline based on sodium hydroxide NaOH. In our country, a chemical lime absorber HP-I is used. The carbon dioxide absorption reaction is exothermic, so heated air enters the breathing bag from the cartridge. Depending on the type of sorbent, the air passing through the regenerative cartridge is either dried or humidified. In the latter case, during its further movement, condensate forms in the elements of the air duct system.
The second phase of air regeneration takes place in the breathing bag, where oxygen is supplied from the oxygen supply system in a volume slightly larger than it is consumed by a person, and determined by the method of oxygen supply of this type of DASK.
In the DASK air duct system, the regenerated air is also conditioned, which consists in bringing its temperature and humidity parameters to a level suitable for human inhalation. Usually air conditioning is reduced to its cooling.
The respiratory bag performs a number of functions and is an elastic container for receiving air exhaled from the lungs, which then enters for inspiration. It is made of rubber or gas-tight rubberized fabric. In order to ensure deep breathing during heavy physical exertion and separate deep exhalations, the bag has a useful capacity of at least 4.5 liters. In the breathing bag, oxygen is added to the air leaving the regenerative cartridge. The breathing bag is also a collection of condensate (if any); sorbent dust is retained in it, which in a small amount can penetrate from the regenerative cartridge; the primary cooling of the hot air coming from the cartridge occurs due to heat transfer through the bag walls to the environment. The breathing bag controls the operation of the excess valve and lung machine. This control can be direct or indirect. With direct control, the wall of the breathing bag directly or through a mechanical transmission acts on the excess valve or lung machine valve. With indirect control, these valves open from the impact on their own sensing elements (for example, membranes) of pressure or vacuum created in the inhalation bag when it is filled or emptied.
The excess valve serves to remove excess gas-air mixture from the airway system and operates at the end of expiration. In the event that the operation of the excess valve is controlled indirectly, there is a risk of losing part of the gas-air mixture from the breathing apparatus through the valve as a result of accidental pressure on the wall of the breathing bag. To prevent this, the bag is placed in a rigid housing.
Refrigerator is used to reduce the temperature of inhaled air. Air coolers are known, the action of which is based on the transfer of heat through their walls to the environment. Refrigerators with a refrigerant are more efficient, the operation of which is based on the use of the latent heat of phase transformation. Water ice, sodium phosphate and other substances are used as a melting refrigerant, ammonia, freon, etc. are used as evaporating into the atmosphere. Carbon dioxide (dry) ice is also used, which immediately turns from a solid state into a gaseous one. There are refrigerators equipped with refrigerant only when operating at elevated ambient temperatures.
The schematic diagram shown in fig. 2.2 is general for all groups and varieties of modern DASC.
In various models of DASC, three schemes of air circulation in the air duct system are used: circular (see Fig. 2.2), pendulum and semi-pendulum.
Main advantage circular scheme - the minimum volume of harmful space, which includes, in addition to the volume of the front part, only a small volume of air ducts at the junction of the branches of inhalation and exhalation.
Pendulum scheme differs from the circular one in that in it the branches of inhalation and exhalation are combined, and the air through the same channel moves alternately (like a pendulum) from the lungs to the breathing bag, and then in the opposite direction. With regard to the circular circuit (see Fig. 2.2), this means that it does not have breathing valves 5 and 6, the hose 4 and refrigerator 8 (in some devices, a refrigerator is placed between the regenerative cartridge and the front part). The pendulum circulation scheme is mainly used in devices with a short protective action time (in self-rescuers) in order to simplify the design of the device. The second reason for using such a scheme is to improve the sorption of carbon dioxide in the regenerative cartridge and use for this additional absorption during the secondary passage of air through the cartridge.
The pendulum air circulation scheme is distinguished by an increased volume of harmful space, which, in addition to the front part, includes a breathing hose, the upper air cavity of the regenerative cartridge (above the sorbent), and the air space between the spent sorbent grains in its upper (frontal) layer. With an increase in the height of the spent sorbent layer, the volume of this part of the harmful space increases. Therefore, DASC with pendulum circulation is characterized by an increased content of carbon dioxide in the inhaled air compared to the circular scheme. In order to reduce the volume of harmful space to a minimum, the length of the breathing hose is reduced, which is possible only for devices located in the working position on the human chest.
Semi-pendulum scheme differs from the circular one in the absence of an exhalation valve 5 (see Fig. 2.2). When exhaling, air moves through the exhalation hose 3 and regenerative cartridge 7 into the breathing bag 9 in the same way as in the circular pattern. When you inhale, most of the air enters the front part 1 through the fridge 8, inhalation valve 6 and inhalation hose 4, and some of its volume passes through the regenerative cartridge 7 and the hose 3 in the opposite direction. Since the resistance of the exhalation branch containing the regenerative cartridge with the sorbent is greater than that of the inhalation branch, a smaller volume of air passes through it in the opposite direction than through the inhalation branch.
DASKs are known with a circular air circulation scheme, in which, in addition to the main breathing bag 9 (see Fig. 2.2), there is an additional bag located between the exhalation valve 5 and the regenerative cartridge 7. This bag serves to reduce the exhalation resistance due to "smoothing" peak value of the air volume flow.
At the beginning of the last century, devices with forced air circulation through a regenerative cartridge were widely used. They had two breathing bags and an injector fed with compressed oxygen from a cylinder and sucking air through a regenerative cartridge from the first bag to the second. This technical solution was due to the fact that at that time regenerative cartridges had a high resistance to air flow. Forced circulation made it possible to significantly reduce expiratory resistance. In the future, injector devices did not become widespread due to the complexity of the design, the creation of a rarefaction zone in the air duct system, which contributes to the suction of outside air into the device. The decisive argument in refusing to use injector devices was the creation of more advanced regenerative cartridges with low resistance. During the period of use of injector devices and after their abandonment, all other devices were called the obsolete term "lung-power breathing apparatus".
The refrigerator is an obligatory element of DASK. Many older models do not have it, and the air heated in the regenerative cartridge is cooled in the breathing bag and inspiratory hose. Air (or other) coolers are known, located after the regenerative cartridge, in the breathing bag, or constituting a single structural unit with it. The last modification also includes the so-called “iron bag”, or “bag inside out”, which is a sealed metal tank, which is the body of the DASK, inside which there is an elastic (rubber) bag with a neck that communicates with the atmosphere. The elastic container, into which air enters from the regenerative cartridge, in this case is the space between the walls of the reservoir and the inner bag. This technical solution is characterized by a large surface area of the tank serving as an air cooler and a significant cooling efficiency. A combined breathing bag is also known, one of the walls of which is simultaneously the lid of the device's knapsack and an air cooler. Breathing bags combined with air coolers, due to the complexity of the design, not compensated by a sufficient cooling effect, are currently not widespread.
The redundant valve can be installed anywhere in the ductwork system, except for the area to which oxygen is directly supplied. However, valve opening (direct or indirect) must be controlled by the counterlung. In the event that the supply of oxygen to the air duct system significantly exceeds its consumption by a person, a large volume of gas escapes into the atmosphere through the excess valve. Therefore, it is advisable to install the specified valve before the regenerative cartridge in order to reduce the carbon dioxide load on the cartridge. The installation location of the excess and breathing valves in a particular model of the device is selected from design considerations. There are DASKs, in which, unlike the scheme shown in Fig. 2.2, breathing valves are installed at the top of the hoses at the junction box. In this case, the mass of the elements of the apparatus, which falls on the face of a person, slightly increases.
Variants and modifications of the circuit diagram of the oxygen supply system of breathing apparatus with compressed oxygen are predetermined primarily by the method of oxygen reservation implemented in this apparatus.
The device (Fig. 3.23) includes: a suspension system 1, a cylinder with a valve 2, a reducer 3, a hose with a lung machine 4, a panoramic mask 5, a capillary with an alarm device 6, an adapter 7, a rescue device 8.
Rice. 3.23 . The general arrangement of the breathing apparatus PTS "PROFI":
1- suspension system; 2- cylinder with a valve; 3- reducer; 4- hose with a lung machine; 5- panoramic mask; 6 - capillary with a signaling device; 7- adapter; 8- rescue device
suspension system(Fig. 3.24) serves to fasten systems and units of the device on it and consists of a plastic back 1, a system of belts: shoulder 2, end 3, fixed on the back with buckles 4, belt 5 with a quick-release adjustable buckle.
Lodgment 6 serves as a support for the balloon. The cylinder is fixed by a balloon belt 7 with a special buckle.
Rice. 3.24. Suspension system of breathing apparatus PTS "PROFI":
1- plastic back; 2 shoulder straps; 3- end belts;
4- buckles; 5- waist belt; 6- lodgment; 7-ball belt with special buckle
Balloon designed to store the working supply of compressed air. Depending on the model of the apparatus, steel and metal-composite cylinders can be used.
A conical thread is cut in the neck of the cylinder, along which a shut-off valve is screwed into the cylinder. On the cylindrical part of the cylinder, the inscription "AIR 29.4 MPa" is applied (Fig. 3.25).
Rice. 3.25. Cylinder for storing the working supply of compressed air
Cylinder valve(Fig. 3.26) consists of a body 1, a tube 2, a valve 3 with an insert, a cracker 4, a spindle 5, a stuffing box nut 6, a handwheel 7, a spring 8, a nut 9 and a plug 10.
The tightness of the valve is ensured by washers 11 and 12. Washers 12 and 13 reduce friction between the spindle collar, the end face of the handwheel and the ends of the gland nut when the handwheel rotates.
Rice. 3.26 . Cylinder valve:
1- body; 2- tube; 3- valve with insert; 4- cracker; 5- spindle; 6- gland nut; 7- handwheel; 8- spring; 9- nut; 10- plug; 11, 12, 13 washers
The tightness of the valve at the junction with the cylinder is ensured by a fluoroplastic sealing material (FUM-2).
When the handwheel is rotated clockwise, the valve, moving along the thread in the valve body, is pressed by the insert against the seat and closes the channel through which air enters the gearbox from the cylinder. When the handwheel is rotated counterclockwise, the valve moves away from the seat and opens the channel.
The principle of operation of the device PTS "PROFI"
The device operates according to an open breathing scheme (Fig. 3.27) with exhalation into the atmosphere and works as follows:
Rice. 3.27. Schematic diagram of the operation of the PTS "PROFI" apparatus:
1- valve (valve); 2- balloon (cylinders); 3- collector; 4- filter; 5- reducer; 6- safety valve; 7- hose; 8- adapter; 9- valve; 10 - lung machine; 11- mask; 12- glass; 13 - inhalation valves; 14- exhalation valve; 15-valve box; 16 - high pressure capillary tube; 17 - manometer; 18- hose; 19- whistle; 20 - signaling device; A - high pressure cavity; B - reduced pressure cavity; B - cavity of the mask; G- cavity for breathing; D- cavity of the pulmonary automaton
when valve(s) 1 are opened, high-pressure air enters from cylinder(s) 2 into collector 3 (if available) and filter 4 of reducer 5, into high-pressure cavity A and, after reduction, into reduced pressure cavity B. The reducer maintains a constant reduced pressure in cavity B, regardless of the change in inlet pressure.
In the event of a malfunction of the reducer and an increase in the reduced pressure, the safety valve 6 is activated.
From the cavity B of the reducer, air enters through the hose 7 into the lung machine 10 or into the adapter 8 (if any) and then through the hose 7 into the lung machine 10. The rescue device 21 is connected through the valve 9.
The lung machine maintains a predetermined excess pressure in the cavity D. When inhaling, air from the cavity D of the lung machine is supplied to the cavity B of the mask 11. The air, blowing the glass 12, prevents it from fogging. Further, through the inhalation valves 13, the air enters the cavity G for breathing.
When exhaling, the inhalation valves close, preventing exhaled air from reaching the glass. To exhale air into the atmosphere, the exhalation valve 14, located in the valve box 15, opens.
To control the air supply in the cylinder, air from the high-pressure cavity A flows through the high-pressure capillary tube 16 to the pressure gauge 17, and from the low-pressure cavity B through the hose 18 to the whistle 19 of the signaling device 20. When the working air supply in the cylinder is exhausted, the whistle is turned on, a warning sound signal about the need to immediately exit to a safe area.
Purpose, device and principle of operation of the reducer of the PTS "PROFI" apparatus
Reducer(Figure 3.28) is designed to convert high (primary) air pressure in the cylinder in the range of 29.4-1.0 MPa to a constant low (secondary) pressure in the range of 0.7-0.85 MPa. The reverse action piston reducer with a balanced pressure reducing valve makes it possible to stabilize the secondary pressure when the primary pressure varies over a large range.
Rice. 3.28. Scheme of the reducer of the apparatus PTS "PROFI":
1- case; 2- eye; 3- insert; 4, 5- sealing rings; 6- body; 7- saddle; 8- pressure reducing valve; 9- nut; 10- washer; 11- piston; 12- rubber sealing ring; 13, 14 - springs; 15- adjusting nut; 16- locking screw; 17- hull lining; 18 - fitting; 19- sealing ring; 20- screw for capillary connection; 21 - fitting for connecting an adapter or hose; 22 - fitting; 23- coupling; 24- filter; 25- screw; 26, 27- O-rings
The gearbox consists of a body 1 with an eyelet 2 for attaching the gearbox to the back, an insert 3 with sealing rings 4 and 5, a body b with a seat 7, a pressure reducing valve 8, on which a piston 11 with a rubber sealing ring 12 is fixed with a nut 9 and a washer 10 , springs 13 and 14, adjusting nut 15 and locking screw 16.
A lining 17 is put on the gearbox housing to prevent contamination. The gearbox housing has a fitting 18 with a sealing ring 19 and a screw 20 for connecting a capillary, and a fitting 21 for connecting an adapter or hose.
A fitting 22 with a coupling 23 is screwed into the gearbox housing for connection to the cylinder valve. A filter 24 is installed in the fitting, fixed with a screw 25. The tightness of the connection between the fitting and the body is ensured by the sealing ring 26. The tightness of the connection between the valve and the gearbox is ensured by the sealing ring 27.
The design of the gearbox provides safety valve, (Fig. 3.29.) Which consists of a valve seat 28, a valve 29, a spring 30, a guide 31 and a lock nut 32. The valve seat is screwed into the gear piston. The tightness of the connection is ensured by the sealing ring 33.
In the absence of pressure in the gearbox, the piston is in the extreme position under the action of the springs, while the pressure reducing valve is open.
When the cylinder valve is open, high-pressure air enters the reducer chamber and creates a pressure under the piston, the value of which depends on the degree of compression of the springs. In this case, the piston, together with the pressure reducing valve, moves, compressing the springs until a balance is established between the air pressure on the piston and the force of the springs, and the gap between the seat and the pressure reducing valve is closed.
When inhaling, the pressure under the piston decreases, the piston with the pressure reducing valve moves under the action of the springs, creating a gap between the seat and the valve, ensuring the flow of air under the piston and further into the lung machine. By turning the nut 15, the reduced pressure is adjusted. During normal operation of the gearbox, the safety valve 29 is pressed against the valve seat 28 by the force of the spring 30.
Rice. 3.29. Reducer relief valve:
28- valve seat; 29- valve; 30- spring; 31 - guide; 32- locknut; 33- o-ring
When the reduced pressure rises above the set value, the valve, overcoming the resistance of the spring, moves away from the seat, and the air from the gearbox cavity escapes into the atmosphere. The rotation of the guide 31 regulates the response pressure of the safety valve.
The front part of the PTS "Obzor"
The front part is designed to protect the respiratory and vision organs from the effects of a toxic and smoky environment and connect the human respiratory tract with the lung machine (Fig. 3.30).
Rice. 3.30. Front part "Overview":
1- case; 2- glass; 3- half clips; 4- screws; 5- nuts; 6- intercom; 7- collar; 8-valve box with a socket for a plug-in connection with a lung machine; 9- collar; 10- screw; 11- spring; 12- button; 13- exhalation valve; 14- hardness disk; 15 - overpressure spring; 16- cover; 17- screws; 18 - headband; 19- forehead strap; 20 - two temporal straps; 21 - two occipital straps; 22, 23 - buckles; 24 - mask holder; 25 - inhalation valves; 26- bracket; 27- nut; 28- washer; 29 - neck strap
The front part of the PTS "Obzor" consists of a body 1 with glass 2, fixed with the help of semi-clamps 3 with screws 4 with nuts 5, an intercom 6, fixed with a clamp 7 and a valve box 8, with a socket for a plug connection with a lung machine.
The valve box is attached to the body using a clamp 9 with a screw 10. The fixation of the lung governed demand valve in the valve box is provided by the spring 11. The lung machine is disconnected from the valve box by pressing the button 12. The valve box is equipped with an exhalation valve 13 with a stiffness disk 14, an overpressure spring 15. The valve box is closed with a cover 16 fixed on the valve box with screws 17.
On the head, the front part is fastened with the help of a headband 18, consisting of interconnected straps: frontal 19, two temporal 20 and two occipital 21, connected to the body by buckles 22 and 23.
The mask holder 24 with inhalation valves 25 is attached to the body of the front part using the body of the intercom and bracket 26, and to the valve box - with a nut 27 with a washer 28.
The headband serves to fix the front part on the user's head. The buckles 22, 23 allow a quick adjustment of the front part directly on the head.
For wearing the face piece around the user's neck while awaiting use, a neck strap 29 is attached to the bottom buckles of the face piece.
When inhaling, air from the submembrane cavity of the lung machine enters the cavity under the mask and through the inhalation valves into the mask. In this case, the panoramic glass of the front part is blown, which eliminates its fogging.
When exhaling, the inhalation valves close, preventing exhaled air from reaching the face glass. The exhaled air from the undermask space is released into the atmosphere through the exhalation valve.
The spring presses the exhalation valve to the seat with a force that allows maintaining a predetermined excess pressure in the undermask space of the front part.
The intercom provides the transmission of the user's speech when the front part is put on the face and consists of a body 29, a clamping ring 30, a membrane 31 and a nut 32.
The front part of "Panorama Nova Standard" No. R54450 is dimensionless, universal. The front part of the Obzor PTS is selected depending on the anthropometric size of the human head.
The selection of the front part of the PTS "Obzor" of the required body height should be made depending on the value of the horizontal (capped) head girth indicated in Table. 3.2.
Table 3.2. Values of the horizontal (cap) girth of the head
The selection of the front part of the PTS "Obzor" according to the size of the mask should be made depending on the value of the morphological height of the face (distance from the lower part of the chin to the nose point), indicated in Table. 3.3.
Table 3.3. Morphological face height values
The air supply system of the device consists of a lung machine and a reducer, it can be single-stage, without a reducer and two-stage. The two-stage air supply system can be made of one structural element that combines the gearbox and the lung machine or separately.
The devices are produced by manufacturers in various versions.
The main nodes of DAVS, their purpose
suspension system designed to mount systems and components of the device on it.
Consists: plastic back, shoulder and end straps fastened to the back with buckles, waist belt with quick-release adjustable buckle. Lodgment which serves as a support for the cylinder. The balloon is fixed with a balloon strap with a special buckle.
Marking: trademark of the manufacturer, symbol of the device, technical specification number, serial number, month and year of manufacture.
Cylinder with valve designed to store the working supply of compressed air.
The valve consists of: body, valve, gasket, 2 rings, cover, spindle, handwheel, cover, safety diaphragm, shut-off valve, shock absorber.
Marking: cylinder designation, heat treatment stamp, quality control stamp, manufacturer's code, lot number, number of the cylinder in the lot, month and year of manufacture, year of the next survey, empty cylinder mass, working pressure, test pressure, nominal volume.
Reducer designed to convert high air pressure in a cylinder to a constant reduced pressure. The reducer has a safety valve (and also a signaling device mechanism can be structurally built into the reducer).
Consists: housing, reduced valve, piston, spring, handwheel, threaded fitting, sealing ring, cuff, safety valve, seal.
Capillary it is intended for accession to a reducer of the manometer and a sound signal.
Consists: 2 fittings connected by a high-pressure spiral tube soldered into them, inside the spiral of which the cable is also connected to fittings, are inside 2 fittings connected and fixed by a hose with caps, sealing rings.
pressure gauge designed to control the pressure of compressed air in the cylinder, a sound signal to alert you that the air in the cylinder is running out.
Lung machine is designed to automatically supply air to the user's breathing, maintain excess pressure in the undermask space, additional air supply, shut off the air supply and connect the front part to the device. The lung machine turns on at the first breath, turns off by pressing the button for additional air supply.
Consists: valve, spring, ring, diaphragm, valve seat, support, stem, button, cover.
panoramic mask It is designed to protect the respiratory organs and human vision from a toxic and smoky environment and connects the human respiratory tract with the lung machine.
Consists: housing with headband straps, panoramic glass, two half-rings, a mask holder with two inhalation valves, an intercom, a plug connection for attaching a lung governed demand valve of a spring-loaded exhalation valve.
Adapter designed to connect the main front part of the lung machine and the rescue device to the gearbox.
Consists: tee, a connector interconnected by a hose which is fixed to the fittings of the tee by caps. A bushing is screwed into the connector housing, on which the hose fitting fixing unit is mounted and consists of: clips, balls, bushings, springs, housing, sealing ring, valve.
rescue device designed to protect the respiratory organs and eyesight of the victim from an environment unsuitable for breathing.
Consists: helmet mask, lung machine and low pressure hose.
Air insulating apparatus for firefighters AIR-98MI and PTS "PROFI" are designed for individual protection of the respiratory organs and human vision from the harmful effects of a toxic and smoky gas environment unsuitable for breathing when extinguishing fires in buildings, structures and production facilities for various purposesin temperature rangeenvironment from minus 40 to60°C and stay in an environment with a temperature of 200°C for 60 s.
BREATHING APPARATUS FOR FIRE AIR-98MI
The main technical characteristics of the apparatus AIR-98MI and its modifications are given in Table.
The apparatus is made according to an open scheme with exhalation into the atmosphere.
When valve(s) 1 are opened, high-pressure air enters from cylinder(s) 2 into collector 3 (if available) and filter 4 of reducer 5, into high-pressure cavity A and, after reduction, into reduced pressure cavity B. The reducer maintains a constant reduced pressure in cavity B, regardless of the change in inlet pressure. In the event of a malfunction of the reducer and an increase in the reduced pressure, the safety valve 6 is activated. From the cavity B of the reducer, air enters through the hose 7 into the lung machine 11 or into the adapter 8 (if any) and then through the hose 10 into the lung machine 11. Through valve 9 it is connected rescue device.
The lung machine maintains a predetermined excess pressure in the cavity D. When inhaling, air from the cavity D of the lung machine is supplied to the cavity B of the mask 13, air blowing around the glass 14 prevents it from fogging. Then, through the inhalation valves 15, the air enters the cavity G for breathing.
Schematic diagram of the breathing apparatus AIR-98 MI
To control the air supply in the cylinder, air from the high-pressure cavity A flows through the high-pressure capillary tube 18 to the pressure gauge 19, and from the low-pressure cavity B through the hose 20 to the whistle 21 of the signaling device 22.
When the working air supply in the cylinder is exhausted, a whistle is turned on, warning with an audible signal of the need to immediately exit to a safe area.
RESPIRATORY APPARATUS PTS "PROFI"
The devices are produced in various versions, differing in the following features:
Complete with various types and number of cylinders;
Complete with various types of front parts;
Possibility of completing with a rescue device.
The device is an insulating reservoir breathing device with compressed air with a working pressure of 29.4 MPa and excess pressure under the front part. The device is equipped with a panoramic mask PTS "Obzor" TU 4854-019-38996367-2002 or "Panorama Nova Standart" No. R54450.
The apparatus operates according to an open breathing scheme with exhalation into the atmosphere and operates as follows: when valve(s) 1 are opened, high-pressure air enters from cylinder(s) 2 into collector 3 (if available) and filter 4 of reducer 5, into the cavity of high pressure A and after reduction into the reduced pressure cavity B. The reducer maintains a constant reduced pressure in the cavity B, regardless of the change in inlet pressure.
In the event of a malfunction of the reducer and an increase in the reduced pressure, the safety valve 6 is activated.
From cavity B of the reducer, air enters through hose 7 into lung machine 11 and into adapter 8 and further through hose 10 into lung machine 11. A rescue device is connected through valve 9.
The lung machine maintains a predetermined excess pressure in the cavity D. When inhaling, air from the cavity D of the lung machine is supplied to the cavity B of the front part 13. The air, blowing the glass 14, prevents it from fogging. Then, through the inhalation valves 15, the air enters the cavity G for breathing.
Schematic diagram of the breathing apparatus PTS "Profi"
When exhaling, the inhalation valves close, preventing exhaled air from reaching the glass. To exhale air into the atmosphere, the exhalation valve 16, located in the valve box 17, opens.
To control the air supply in the cylinder, air from the high-pressure cavity A flows through the high-pressure capillary tube 18 to the pressure gauge 19, and from the low-pressure cavity B through the hose 20 to the whistle 21 of the signaling device 22. When the working air supply in the cylinder is exhausted, the whistle is turned on, a warning sound signal that only the reserve air supply remains in the device.
Rice. 1. Scheme of preparation and admission of gas and smoke protectors to work in RPE
In addition, personnel admitted by the military medical (medical) commission to use RPE are required to undergo an annual medical examination.
Personnel from among the gas and smoke protectors undergo certification in the manner prescribed by the rules for attestation of personnel of the State Fire Service for the right to work in personal respiratory and vision protection equipment (Appendix 1).
The training of personnel in order to obtain the qualification (specialty) of a senior master (master) of the GDZS is organized by the territorial bodies of the EMERCOM of Russia in training centers, in the prescribed manner. Personnel temporarily acting as full-time senior masters (masters) of the GDZS must have appropriate training.
The admission of personnel who have completed training to perform duties as a senior foreman (master) of the GDZS is issued by order of the territorial body of the EMERCOM of Russia.
For the practical training of gas and smoke protectors for work in RPE in an environment unsuitable for breathing, each local fire brigade garrison should be equipped with heat and smoke chambers (smoke chambers) or training complexes, as well as firing lanes for the psychological training of firefighters.
2. BREATHING APPARATUS WITH COMPRESSED AIR
2.1. Appointment of breathing apparatus
A breathing apparatus with compressed air is an insulating reservoir apparatus in which a supply of air is stored in cylinders in a pressurized state in a compressed state. The breathing apparatus operates according to an open breathing scheme, in which air is taken from the cylinders for inhalation, and exhalation is made into the atmosphere.
Compressed air breathing apparatus are designed to protect the respiratory organs and eyesight of firefighters from the harmful effects of an unbreathable, toxic and smoky gaseous environment when extinguishing fires and performing rescue operations.
2.2. Main performance characteristics
Consider the AP-2000 breathing apparatus, which operates according to an open breathing scheme (inhalation from the apparatus - exhalation into the atmosphere) and is intended for:
protection of respiratory organs and human vision from the harmful effects of a toxic and smoky gaseous environment when extinguishing fires and emergency rescue operations in buildings, structures and industrial facilities; evacuation of the victim from an area with unbreathable gas
environment when used with a rescue device.
The technical characteristics of the device and its components comply with the requirements of fire safety standards NPB-165-2001, NPB-178-99, NPB-190-2000.
The device is operational at air pressure in the cylinder (cylinders) from 1.0 to 29.4 MPa (from 10 to 300 kgf/cm2). In the undermask space of the front part* of the apparatus, during breathing, excess pressure is maintained with lung ventilation up to 85 l/min and the ambient temperature range from -40 to +60 °C.
Excessive pressure in the undermask space at zero air flow - (300 ± 100) Pa ((30 ± 10) mm of water column).
The time of the protective action of the apparatus with pulmonary ventilation of 30 l / min (moderate work) corresponds to the values \u200b\u200bspecified in Table. one.
Table 1 |
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Time of protective action of the apparatus AP-2000 Standard** |
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Balloon parameters |
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protective |
Technical |
Guarantee, |
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actions, |
device, |
characteristics, |
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l/kgf/cm2 |
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Steel |
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metal composite |
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metal composite |
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metal composite |
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metal composite |
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The volume fraction of carbon dioxide in the inhaled mixture is not more than 1.5%.
* The front part of the device is a full-face panoramic mask, hereinafter referred to as the mask.
**AP-2000 Standard - complete with mask PM-2000 and lung machine AP2000
The actual resistance to breathing on exhalation during the entire time of the protective action of the apparatus and with pulmonary ventilation of 30 l/min (moderate work) does not exceed: 350 Pa (35 mm of water column) - at an ambient temperature of +25 °C; 500 Pa (50 mm w.g.) - at an ambient temperature of -40 °C.
Air consumption during operation of the additional supply device (bypass) - not less than 70 l / min in the non-pressure range from 29.4 to 1.0 MPa (from 300 to 10 kgf / cm2).
The valve of the lung machine of the rescue device opens at a vacuum of 50 to 350 Pa (from 5 to 35 mm of water column) at a flow rate of 10 l / min.
The high and reduced pressure systems of the apparatus are sealed, and after closing the cylinder valve (cylinder valves), the pressure drop does not exceed 2.0 MPa (20 kgf/cm) per minute.
The high and reduced pressure systems of the apparatus with the connected rescue device are sealed, and after closing the cylinder valve (cylinder valves), the pressure drop does not exceed 1.0 MPa (10 kgf/cm2) per minute.
The air duct system of the apparatus with a connected rescue device is sealed, while creating a vacuum and overpressure of 800 Pa (80 mm of water column), the pressure change in it does not exceed 50 Pa (5 mm of water column) per minute.
The alarm device is triggered when the pressure in the cylinder drops to 6–0.5 MPa (60–5 kgf/cm2), while the signal sounds for at least 60 seconds.
The sound pressure level of the signaling device (when measured directly at the sound source) is at least 90 dBA. In this case, the frequency response of the sound created by the signaling device is in the pre-
cases 800 ... 4000 Hz.
Air consumption during operation of the signaling device - no more than 5 l / min. The cylinder valve is tight in the "Open" and "Closed" positions when
all tank pressures.
The valve is operational for at least 3000 opening and closing cycles.
The pressure at the outlet of the reducer (without flow) is:
not more than 0.9 MPa (9 kgf/cm2) at pressure in the cylinder of the apparatus 27.45...29.4
MPa (280...300 kgf/cm2);
not less than 0.5 MPa (5 kgf / cm2) at a pressure in the cylinder of the device 1.5 MPa
(15 kgf/cm2).
The safety valve of the reducer opens when the pressure at the outlet of the reducer is not more than 1.8 MPa (18 kgf/cm2).
Cylinders of the apparatus withstand at least 5000 loading cycles (fillings) between zero and working pressure.
The term for re-examination of the cylinders of the apparatus is: 3 years for metal-composite cylinders; 5 years for a steel cylinder SNPP "SPLAV";
6 years (primary), 5 years - subsequent for the company's steel cylinder
The service life of the cylinders of the apparatus is: 16 years for steel "FABER";
11 years for the steel GNPP "SPLAV";
10 years for metal-composite CJSC NPP Mashtest;
15 years for metal composite "LUXFER LCX". The average service life of the apparatus is 10 years. The mass of the mask does not exceed 0.7 kg.
According to the type of climatic version, the device belongs to the version of the location category 1 according to GOST 15150-96, but is designed for use at an ambient temperature of -40 to +60 ° C, relative humidity up to 100%, atmospheric pressure from 84 to 133 kPa (from 630 to 997.5 mm Hg).
The device is resistant to aqueous solutions of surface-active substances (surfactants).
Mask, lung governed demand valve and rescue device are resistant to disinfectants used in sanitation:
rectified ethyl alcohol GOST 5262-80; aqueous solutions: hydrogen peroxide (6%), chloramine (1%), boric
acid (8%), potassium permanganate (0.5%).
2.3. The device and principle of operation of breathing apparatus
The basis of the apparatus (Fig. 2) is suspension system, which serves to mount all parts of the device on it and fasten it to the human body, including the base 14 , shoulder straps 1 , end straps 13 and waist belt 17 .
Rice. 2. Breathing apparatus AP-2000: 1 - shoulder straps; 2 - low pressure hose; 3 - balloon; 4 - signal device hose; 5 - whistle; 6 - housing of the signaling device; 7 - pressure gauge; 8 - nipple; 9 - high pressure hose; 10 - valve handwheel; 11 - rescue device lock; 12 - hose; 13 - trailer belts; 14 - base; 15 - belt; 16 - lock; 17 - waist belt
The following components of the device are mounted on the suspension system: cylinder with valve 3; gearbox (Fig. 3), fixed on base 14 with a bracket; a signaling device with a pressure gauge 7 , a body 6 , a whistle 5 and a hose 4 coming from the gearbox along the left shoulder strap; low pressure hose 2, laid along the right shoulder belt, connecting the gearbox with the lung machine (Fig. 4, 6); hose 12 with lock 11 for connecting the rescue device (Fig. 5) to the device, coming from the gearbox along the right side of the waist belt; high pressure hose 9 with a plug nipple 8 for recharging the device by bypass, coming from the gearbox along the left side of the waist belt.
For more convenient mounting of the device on the user's body, the suspension system provides for the possibility of adjusting the length of the straps.
To adjust the position of the shoulder straps, depending on the body size of the user, two groups of grooves are provided in the upper part of the base of the device.
Cylinder with valve is a container for storing a supply of compressed air suitable for breathing. The cylinder 3 (see Fig. 2) is tightly packed into the base 14 lodgement, while the upper part of the cylinder is fastened to the base with a belt 15 with a lock 16 having a latch that prevents accidental opening of the lock.
To protect against damage to the surface of metal-composite cylinders
and a cover can be applied to extend their service life. The cover is made of thick red fabric. A white reflective tape is sewn on the surface of the cover, which allows you to control the location of the user of the device in conditions of poor visibility.
signaling device designed to give an audible signal,
warning the user about reducing the air pressure in the cylinder to 5.5 ... 6.8 MPa (55 ... 68 kgf / cm2), and consists of a body 6 (see Fig. 2) and a whistle 5 and a pressure gauge 7 screwed into it. The manometer of the apparatus is designed to control the pressure of compressed air in the cylinder with the valve open.
The reducer (Fig. 3) is designed to reduce the pressure of compressed air
and feeding it to the lung machines of the device and the rescue device.
On the housing 1 of the gearbox there is a threaded fitting 3 with a handwheel 2 for connection with the cylinder valve.
The built-in safety valve 6 of the reducer protects the low-pressure cavity of the apparatus from an excessive increase in pressure at the outlet of the reducer.
The gearbox provides operation without adjustment during the entire service life and is not subject to disassembly. The reducer is sealed with sealing paste, in case of violation of the safety of the seals, claims to the operation of the reducer are not accepted by the manufacturer.
Depending on the configuration, the apparatus may include two types of masks: PM-2000 with lung machine 9V5.893.497 (option 1); "Pana Sil" made of neoprene or silicone with a rubber or mesh headband with lung machine 9B5.893.460 (option 2).
Rice. 3. Reducer: 1 - reducer housing; 2 - handwheel; 3 - threaded fitting; 4 - ring 9V8.684.909; 5 - cuff; 6 - safety valve; 7 - filling
The mask (Fig. 4) is designed to isolate the respiratory organs and human vision from the environment, supply air from the lung machine 6 for breathing through the inhalation valves 3 located in the mask holder 2, and remove the exhaled air through the exhalation valve 8 into the environment.
Rice. 4. Mask PM-2000 with lung machine: 1 - mask body; 2 - mask holder; 3 - cla-
pans of inspiration; 4 - intercom; 5 - nut; 6 - lung machine; 7 - multifunctional button; 8 - exhalation valve; 9 - hose lung machine; 10 - strap; 11 - lock; 12 - headband straps; 13 - valve box cover
The mask body 1 has a built-in intercom 4 that provides the ability to transmit voice messages.
AT the design of the mask provides for the possibility of adjusting the length of the headband straps 12 .
Lung machine 6(Fig. 4) is designed to supply air to the internal cavity of the mask with excess pressure, as well as to turn on additional continuous air supply in case of failure of the lung machine or lack of air to the user. The lung machine is attached to the mask with the help of
I screw nuts with M45 × 3 thread.
rescue device(Fig. 5) is designed to protect the respiratory organs and eyesight of the injured person when he is rescued by the user of the apparatus and removed from the zone with a gaseous environment unsuitable for breathing.
The rescue device includes:
mask worn in the bag 1, which is the front part of the ShMP-1
height 2 GOST 12.4.166;
lung governed demand valve 2 with bypass button 2.1 and hose 3 .
The lung machine is attached to the mask using a nut 2.2 with a round thread
Loy 40×4.
Rice. 5. Rescue device: 1 -
mask; 2 - lung machine: 2.1 - bypass button;
2.2 - nut; 3 - hose
To connect the rescue device to the device, use hose 12 with a quick-release lock (see Fig. 2), which the manufacturer installs on the device when ordering a rescue device. The design of the lock eliminates accidental undocking during operation.
In the absence of an order, plug 11 is installed on the gearbox (Fig. 6).
Rice. 6. Schematic diagram of the apparatus AP-2000: 1 - lung machine: 1.1 - valve;
1.2, 1.9, 1.10 - spring; 1.3 - ring; 1.4 - membrane; 1.5 - valve seat; 1.6 - support; 1.7 - stock; 1.8 - button; 1.11 - cover; 2 - mask: 2.1 - panoramic glass; 2.2 - inhalation valves; 2.3 - exhalation valve; 3 - balloon with valve: 3.1 - cylinder; 3.2 - valve; 3.3 - handwheel; 3.4 - ring 9v8.684.919; four - signaling device: 4.1 - pressure gauge; 4.2 - whistle; 4.3 - retaining ring; 4.4 - ring; 5 - rescue device: 5.1 - hose; 5.2 - lung machine; 5.3 - mask; 5.4 - bypass button; 5.5 - nipple; 6 - high pressure hose: 6.1 - ring; 7 - hose for connecting the rescue device: 7.1 - lock; 7.2 - sleeve; 7.3 - ball; 7.4 - valve; 8 - reducer: 8.1 - valve; 8.2 - spring; 8.3 - ring 9V8.684.909; 9 - a hose with a plug-in nipple for recharging cylinders; 10 - lung machine hose; 11, 12 - traffic jams; A, B - cavities
Structurally, the lung machine of the rescue device differs from the lung machine of the device in the absence of the possibility of creating excess pressure and the type of thread for attaching to the mask.
Device for recharging the apparatus with air provides an opportunity
the ability to recharge the cylinder of the device by bypassing without interrupting the operation of the device.
The device includes a high-pressure hose 9 (see Fig. 2) with a plug-in nipple 8, which is installed on the device by the manufacturer when ordering a device for recharging, and a hose with a half-coupling for connecting to a high pressure source.
In the absence of an order for the device, plug 12 is installed on the gearbox (Fig. 6).
Device management(see Fig. 2) is carried out using the valve handwheel 10 .
The opening of the valve occurs when the handwheel is rotated counterclockwise until it stops.
To close the valve, the handwheel is rotated clockwise until it stops without much effort.
The activation of the mechanism of the lung machine with the valve open is carried out automatically - by the effort of the user's first breath.
Switching off the mechanism of the lung machine is carried out forcibly as follows: press the bypass button all the way, fix it for 1-2 s, then slowly release it.
The auxiliary air supply device (bypass) is turned on by gently pressing the bypass button and holding it in this position.
Air pressure control is carried out by pressure gauge 7, mounted on a hose 4, which is placed on the left shoulder strap of the suspension system. Gauge scale is photoluminescent for use in low light and in the dark.
On fig. 6. A schematic diagram of the apparatus AP-2000 is shown.
Before turning on the device, the valve (s) 3.2 is closed, the valve 8.1 of the gearbox 8 is opened by the force of the spring 8.2, the lung machine 1 is turned off by pressing the button 1.8 all the way.
When switched on, the user opens the valve(s) 3.2. Compressed air contained in the cylinder 3.1, through an open valve 3.2 enters the inlet of the gearbox 8. At the same time, air enters the signal device 4 through the high pressure hose 6 .
Under the action of air pressure coming from the inlet of the gearbox into cavity B, the spring 8.2 is compressed and the valve 8.1 closes. When air is taken through hose 9, the pressure in cavity B decreases and valve 8.1 opens by a certain amount under the action of spring 8.2.
An equilibrium state is established, in which air with a pressure reduced to a working value determined by the force of the spring 8.2 flows through the hose 9 to the inlet of the lung machine 1 and into the cavity of the hose 7 .
With the lung machine 1 turned off and the mask 2 removed from the user's face, the button latch 1.8 is engaged with the membrane 1.4, which is retracted to the extreme non-working position by the force of the spring 1.9 and does not touch the support 1.6, and the valve 1.1 is closed by the force of the spring 1.2. When the mask is put on the face during the first breath, a vacuum is formed in the cavity A of the lung machine 1. Under the action of the pressure difference, the membrane 1.4 flexes, jumps off the latch of the button 1.8 and goes into working condition. Under the force of the spring 1.10, the membrane 1.4 presses on the support 1.6 and deflects the valve 1.1 from the seat 1.5 through the stem 1.7.
If the lung machine fails or it is necessary to purge the submask space, the valve 1.1 is opened by pressing and holding the bypass button 1.8, while the air flows continuously. It should be remembered that the inclusion of additional continuous supply reduces the time of the protective action of the device.
The lung machine with the help of a spring 1.10 together with a spring-loaded exhalation valve 2.3 of the mask creates an air flow with excess pressure, which first enters the panoramic glass 2.1, preventing it from fogging, and then through the inhalation valves 2.2 - for breathing.
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