FR2646781A1 - Breathing device and assembly, in particular for unbreathable atmosphere, in particular for contaminated environment - Google Patents

Abstract

The invention relates to a breathing assembly and device. The assembly comprises a breathing device and integral and leaktight closing, the breathing device comprising a mouth/nose mask 3 connected to a purifying cartridge 5 for eliminating carbon dioxide from the expired gases, and valves 6, 6' controlling the circulation of the gases in the mask on inhalation and expiration, the breathing device having a gas inlet E connecting the mouth/nose mask with the environment in which the mask is placed, and a gas outlet S allowing release of expired and purified gases into this atmosphere, the breathing device being arranged such that the said atmosphere is the internal volume of the clothing, the said inlet being arranged to communicate with the top part of the clothing and the said outlet being arranged to direct the gases towards the bottom part of the clothing. Application to breathing in an unbreathable environment, in particular a contaminated environment.

Description

 The invention relates to a respiratory device and assembly, in particular for an unbreathable atmosphere, in particular for a contaminated environment.

 When one wishes to enter a contaminated unbreathable environment, it is known to put on the worker in a waterproof suit and to add an autonomous breathing device.

 For long periods of autonomy, this respiratory circuit is a closed circuit. Such a closed circuit essentially consists of a so-called “false lung” respiratory bag with a volume at least equal to the user's lung capacity, that is to say generally 6 liters and in which respiratory exchanges take place. Means for injecting oxygen and purifying the CO2 keep the gases breathed in this closed circuit under suitable physiological conditions.

 To be perfect, the oxygen supplied must correspond to that consumed, but the consumption in 2 of an individual depends on the work he provides and this consumption can vary by a factor of 10: at rest, the consumption of O2 can only be 0.5 Nl / min while under heavy work it will reach 5 Ni / min.

To meet this requirement, there are 3 methods
1 - Carry out a continuous measurement of the rate of 2 and order from this measurement the supply of 2 to maintain the rate of breathed gases in the vicinity of 21%.

 This complex process is reserved for high performance systems.

 2 - Initially put the circuit under pure 02 and trigger the supply of O2 when, following consumption, the bag collabs at the end of inspiration.

 This commonly used process is simple but requires operation under pure 02, which represents some physiological and fire safety disadvantages.

 3 - Provide 1 '2 continuously and in excess. In these conditions, taking into account the low value of the general volume of the circuit (6 liters), this constant flow must be practically equal to the maximum instantaneous consumption.

 The system tends towards 1 '2 pure and is not very economical.

 Finally, in all these cases, there is a thermal problem due to the fact that the metabolic heat normally evacuated in the hot exhaled gases is not eliminated, while the absorption of CO2 by chemical process (soda lime) adds calories to the circuit. The breathed gases rise very quickly in temperature to the point of making these devices impractical in long autonomy.

 The drawbacks mentioned above are avoided by using a respiratory assembly which comprises a respiratory device and an integral and waterproof garment, the respiratory device comprising an oro-nasal mask connected to a purifying cartridge for the removal of carbon dioxide from the gases. expiration and valves controlling the circulation of gases in the mask on inspiration and on expiration, this assembly being characterized by the fact that the respiratory device has a gas inlet making the oro-nasal mask communicate with the medium in which is placed the mask and a gas outlet allowing the release of exhaled and purified gases in this medium and by the fact that the respiratory device is arranged so that said medium is the internal volume of the garment, said inlet being arranged to communicate with the upper part of the garment and said outlet being arranged to direct the gases towards the lower part of the garment.

 The present invention, by including all of the waterproof protective clothing in the closed breathing circuit, results in a very simple assembly where the breathing takes place under a low O2 rate and with a temperature of the breathed gases close to Room temperature.

 "Integral" means that the garment covers the entire body.

Generally such a garment, known per se, comprises around the head a totally or partially rigid part.

 It will be noted that part of the characteristics of the assembly of the invention relates to the respiratory device, which can moreover be sold alone, for example for users who already have the garment or who could obtain it otherwise.

 It is therefore in accordance with the invention to claim both the respiratory assembly and the single respiratory device.

 An exemplary embodiment of the invention will be described below with reference to the single figure of the accompanying drawing, the description and the figure showing other particular features of the invention.

 The figure is a schematic view of a user equipped with the device of the invention.

 The user 1 is coated with a flexible, waterproof and integral garment 2 comprising, at the level of the head, a rigid transparent part.

 The body surface is approximately 2 m2 and every centimeter of play between the coat and the body represents 20 liters of air included in the coat.

Experience shows that under such conditions, everyone who dresses like this includes at least 30 liters of air in their clothing. The garment being waterproof, this volume of air is maintained there.

 If the diver, under these conditions breathed the air of the garment, it would quickly become 2 and become enriched in CO2.

 The invention then provides to equip, before dressing, the diver with a respiratory device consisting of an oronasal mask 3 connected by a flexible conduit 4 to a cartridge 5 containing an absorbent of CO2 (soda lime). The device comprises, in a manner known per se, valves 6,6 'which regulate the admission and evacuation of gases into the mask on inspiration and on expiration so as to create a single direction of circulation, in preventing inhalation of exhaled gases and directing exhaled gases towards the cartridge.

 According to the invention, the device has an air inlet E allowing the entry into the mask of the ambient air contained in the upper part of the garment and an outlet S allowing the exhalation gases to be released towards the lower part of the garment refined.

 The valves 6 and 6 'open and close in opposition so that on inspiration only the air present in the upper part of the garment enters the mask and on exhalation the exhaled gases pass exclusively to the cartridge.

 I1 is not necessary to describe in detail the valves 6 and 6 'because they are well known to those skilled in the art, usually found in closed respiratory circuits and the present invention does not claim a particular contruction of inspiratory valves and expiratory.

The hot exhaled gases will have to go up along the garment towards the upper part to be re-inspired. During this journey, the wall of the garment
participates in the evacuation towards the outside of the heat conveyed by these gases.

 As described so far, the CO2 is eliminated but it is advisable to provide a supply of 2 to compensate for that consumed.

 Given the general volume of at least 30 liters of the system, a very simple first method consists in including from the start a certain amount of pure 2 corresponding to the average consumption of the wearer for the expected autonomy.

 For example, for an autonomy of 30 minutes, the average consumption is 1 Nl / min (high consumptions of the order of 5 Nl / min only last a few minutes).

 By including 30 N1 of O2 in the garment, it relaxes to increase in volume only 1.5 cm on average, which is negligible.

The general rate of O2 rises to 60% to slowly deplete and to reach 21% again after 30 minutes of breathing.

 So, because the general volume is important due to the use of the air wheel included in the garment, this version is particularly simple. It is however limited to the autonomy of less than or equal to 30 minutes otherwise the volume of 2 initially included would become excessive.

 For greater autonomy, the invention then provides for distributing the supply dlO2 over time by including, for example, in the spacesuit a small charge of 2 compressed 7 equipped with a flow regulator providing for example 1 Nl / min of 2 pure.

 Under these conditions, for a low workload, the O2 level which is initially 21% of the air included, increases slowly due to the excess of Q2 supplied. This excess is stored in the 30 liters of air, thus making it possible to respond to possible heavy workloads.

 In other words, the large volume of the assembly dampens the fluctuations in the rate of 2 in the spacesuit which can then be fed in this simple form.

 The invention finally provides for the possible use of super oxide such as KO2 as a chemical reagent for absorbing CO2. It is known that under these conditions, the absorption of CO 2 gives off 2 in a proportion similar to physiological exchanges. The slight excess of 2 generally observed with the KO2 is here perfectly absorbed by the large volume of air included in the circuit, and improves the efficiency of this recent technique.

Claims (7)

 1. Respiratory assembly which comprises a respiratory device and an integral and waterproof garment (2), the respiratory device comprising an oro-nasal mask connected to a purifying cartridge (5) for the elimination of carbon dioxide from the exhalation gases and valves (6,6 ') controlling the circulation of gases in the mask on inspiration and on expiration, this assembly being characterized by the fact that the respiratory device has a gas inlet (E) causing the mask to communicate nasal with the medium in which the mask is placed and a gas outlet (S) allowing the release of exhaled and purified gases in this medium and by the fact that the respiratory device is arranged so that said medium is the internal volume of the garment , said inlet being arranged to communicate with the upper part of the garment and said outlet being arranged to direct the gases towards the lower part of the garment. 2. Assembly according to claim 1, characterized in that said purifying cartridge (5) is located inside the garment. 3. Assembly according to claim 2, characterized in that the oro-nasal mask and said cartridge are worn by the user inside the garment. 4. Assembly according to one of claims 1 to 3, characterized in that it comprises means (7) for introducing oxygen into the garment. 5. An assembly according to claim 4, characterized in that these means comprise a cylinder of pressurized oxygen.  6. Assembly according to one of claims 1 to 5, characterized in that it comprises peroxides capable of supplying oxygen to the ambient medium by chemical reaction with the carbon dioxide of the exhalation gases. 7. Respiratory device comprising an oro-nasal mask connected to a purifying cartridge (5) for the elimination of carbon dioxide from the exhalation gases and valves (6,6 ') controlling the circulation of gases in the mask inspiration and expiration, this set being characterized in that the respiratory device has a gas inlet (E) communicating the oro-nasal mask with the medium in which the mask is placed and a gas outlet (S) allowing the release of exhaled and purified gases in this medium.