FR3117040A1 - Air curtain facial respiratory protection device, worn on the person's head. - Google Patents

Abstract

Title of the invention: Air curtain facial respiratory protection device, worn on people's heads. The invention relates to a respiratory protective device with a protective air curtain (2.1) created by a diffuser (2). It has high-performance air filtration (3) of the ISO Coarse, ISO PM10, ISO PM2.5, ISO PM1, EPA, HEPA or ULPA type with or without prefilter (3.1) This filtration makes it possible to purify and sanitize the air forming the air curtain (2.1). The air is set in motion by a radial turbine device powered by an autonomous rechargeable energy source. This energy source is also powered by a solar panel to extend autonomy. The flow of filtered and purified air creates a protective air curtain (2.1) around the user's face and external respiratory organs (nose and mouth). The filter is easily removable to be changed and can be completed with a pre-filter. The filter can be modified according to the environment and the context of use. The air curtain flow can be variable by manual or automatic adjustment. A UV device makes it possible to complete the disinfection of the air and to disinfect the filter after its use in an environment with bacteriological or viral risks. Figure for abstract: Fig. 1

Description

Air curtain facial respiratory protection device, worn on the person's head.

Technical area.

The invention relates to a facial protection device with an air curtain and mechanical anti-bacterial, anti-viral or anti-pollution filtration and ultraviolet (UV) disinfection. For simplicity, this device is referred to interchangeably as “device or “mask” in the remainder of the text, even if the mask does not necessarily include a visor.

State of the prior art.

The Sars-Cov2 pandemic, which began at the end of 2019, showed the fragility of our globalized economies in the face of an emerging, resistant and virulent virus, which can cause epidemics, or even a pandemic, by an airborne mode of propagation. Epidemics which can then turn into a global pandemic as is the case with Covid-19. The least impacted places were those where the population has traditionally worn respiratory filter masks outdoors to protect themselves from pollution, as is the case in Hong Kong.

The interest of filtering respiratory air to fight against respiratory pathogens or other disabling, dangerous or inconvenient agents for health (such as airborne pollutants or allergens) is a fact that no longer needs to be demonstrated.

Current respiratory filtration masks generally include a part intended to cover the nose and the mouth and are made of one or more layers of filtering materials. They are placed on the face in a more or less airtight way guaranteeing greater or lesser protection and providing greater or lesser breathing and use discomfort. Some models have a remote filter element and sealing with the face is done using a synthetic waterproof material, generally based on synthetic materials (silicone, polymer, etc.).

These masks must meet the standards in force in terms of air leaks on suction, the quality of filtration (size of the filtered particles), the pressure drop at a given air flow (characterizing the ease to inhale or exhale). The standards currently in force, particularly in Europe, are the EN 143 and EN 149 standards. Thus we distinguish between FFP1 masks (leakage < 22%), FFP2 (leakage < 8%) and FFP3 (leakage < 2%). Particles and aerosols filtered by FFP masks have a minimum size of 0.6 µm (600 nm). However, the size of a viral particle may be smaller than 600 nm since some may be less than 10 nm. The size of Sars-Cov2, responsible for the Covid-19 pandemic, is between 60 and 140 nm. FFP masks can therefore only stop this virus when it is carried by larger particles (PM2.5, PM10). We then speak of an airborne virus.

EPA, HEPA and ULPA filters are characterized by the EN 1822 standard, while PM type filters by the ISO 16-890 standard. These standards define filtration and pressure drop performance.

Surgical masks have been widely used during the Covid-19 pandemic. These masks do not guarantee a seal with the face and thus the efficiency of suction filtration cannot be guaranteed. These masks only reduce or limit the spread of the larger aerosols generated during exhalation. However, they have a dispersive role of aerosols, which makes it possible to fight with very relative effectiveness against the spread of an epidemic by lowering the airborne viral or bacterial load. This relative effectiveness is nevertheless linked to the condition that the entire population wears them permanently.

These half masks, placed only on the mouth and nose, do not guarantee eye protection, yet many pathogens or pollutants can infect the body through the eyes or create ocular discomfort. The eyes being in physical connection with the nose via the tear ducts, they can therefore constitute a passage for respiratory diseases.

All these half masks, certified or not, present discomfort for the user. These discomforts can be divided into two classes: 1) physiological discomfort and 2) psychological discomfort.

The physiological discomfort consists of the respiratory discomfort caused by the loss of pressure, by the presence of very quickly unpleasant expiratory water vapor and by the possible looping of the stale exhaled air. This looping depends on the dead volume of the mask, which varies according to the type of mask. The mask therefore creates a humid and potentially stale respiratory environment, contraindicated for people with rhinitis, allergic rhinitis and asthma. This discomfort prohibits or makes very painful any sports practice, with a mask. The mere presence of this mask, which can stick to the skin, which must be readjusted from time to time, can be the subject of itching, or even contact allergies. Thus, their presence can quickly become annoying and cause a repositioning reflex. However, contact between hands and respiratory masks must be limited as much as possible, so as not to spread microorganisms by contact.

These masks do not allow the wearer to eat (or smoke) and must be removed, exposing them to environmental contaminants.

Finally, these masks, if used for too long, can be a source of bacterial contamination, especially from an endogenous source.

The social and psychological embarrassment of wearing masks in society is another disadvantage of current masks. It limits human communication and in particular the expression of emotions.

Most of these masks are not reusable and must be thrown away after a few hours (we are talking about only 4 hours of effectiveness for surgical masks). The user must therefore be careful not to wear a mask beyond this period, which creates additional psychological stress.

The economic cost of these disposable masks can quickly turn out to be high if the pandemic lasts for many months. Which is the case with the Covid-19 pandemic.

The so-called washable masks, in synthetic or natural fabrics, with or without an additional filtering element, have a longer lifespan (a few dozen washes and therefore possible reuses) but present the same psychological and physiological genes. Moreover, their effectiveness is not at all standardized.

Finally, these masks have an ecological cost: on a planetary level, hundreds of billions of masks are to be manufactured, distributed and treated at the end of their life. During the Covid-19 pandemic, many masks ended up in the environment without any treatment. But these are, most of the time, made of synthetic materials that are very difficult to biodegrade.

The objective of the present invention is to provide a reusable protective device, more comfortable for the user on all the discomforts mentioned and guaranteeing comfort and protection for its user. This by eliminating any application of a mask on the user's face thanks to a curtain of filtered air.

Disclosure of Invention.

According to the invention, the mask-type facial respiratory protection device comprises means producing a curtain of air blown on the face of the user, these means including at least one turbine driven by an electric motor, a diffuser and a power supply autonomous electric.

The air curtain at the outlet of the diffuser is at least 20 mm thick and has a flow rate of at least five times the breathing volume.

According to a first improvement of the invention, the protection device comprises a means of treatment by UV of the air and, where appropriate, of the surfaces of the device.

According to a preferred variant of the invention, the protective device further comprises a transparent or semi-transparent eye protection visor that can be removed and removed quickly, the air curtain being generated between the face and the visor.

Detailed description.

The objects and advantages of the present invention, as well as others, will be better known by reference to the following detailed description in conjunction with the accompanying drawings in which:

represents an overall view in perspective of the mask according to the invention.

shows an exploded view of the filtration unit (1) with the different elements.

shows an exploded rear view of the filtration unit with the settings and regulation unit

represents a variant of the invention provided with a visor.

The invention applies not exclusively to the purification of the air sucked in by the user. The device creates a curtain of air, filtered or not, at the level of the user's face as shown in the .

The air curtain device can also be used in a non-sanitary context, i.e. in an environment where the air is stale or polluted. This is to provide healthier air in an environment where the air would present respiratory risks in order to preserve the health of the user. This is for example, without being limiting, the case of sports practice in a polluted urban environment or in professional environments where the air is loaded with particles or dangerous emanations (PAHs, VOCs, solvents, airborne particles, dust or particles fines, pollen, process fumes, etc.).

This device also makes it possible to fight against respiratory or ocular allergies of sensitive people and to limit health risks in professional environments at risk.

The use of the device in professional environments at risk does not only concern air pollution. In effect ; the air curtain also creates thermal protection for the skin and eyes. For example, it could be used during industrial welding work in addition to or integrated into the eye protection device. In this case, air filtration may be optional if the fresh air comes from a location far enough away from the welding work. Work that gives off toxic fumes and gases. In filtered mode, it would make it possible to limit or even eliminate industrial ventilation in very energy-intensive workshops.

In filtered or unfiltered mode, the creation of an air curtain at face level also improves thermal comfort, especially during heat waves or in hot countries.

Finally, the use of this mask also makes it possible to purify the air of its environment of use. Thus, the air expelled by the mask is filtered and purified. It thus makes it possible to depollute or sanitize the ambient air in closed spaces. It works as a mini portable air purifier. Thus, it improves the air quality of the environment in which it is used.

1. Une unité de traitement de l’air (1) qui va accélérer l’air ambiant pour créer un débit d’air. Ce flux d’air pourra être filtré ou non et traité aux UV ou non.
2. Une unité de diffusion (2) de l’air. C’est un diffuseur d’air au niveau du visage de l’utilisateur qui va créer un rideau d’air aéraulique frontal protecteur (2.1).
3. Une unité de régulation (9).

To do this, the air curtain mask consists of 3 main elements:

1. An air treatment unit (1) which will accelerate the ambient air to create an air flow. This air flow may or may not be filtered and UV treated or not.
2. A diffusion unit (2) of the air. It is an air diffuser at the level of the user's face which will create a protective frontal aeraulic air curtain (2.1).
3. A regulation unit (9).

These 3 elements are integrated in the same room or not. It is possible to deport the air treatment unit or to integrate it into the diffuser. If it is remote, it is connected with an air duct to the diffuser. It is then placed anywhere on the user's body, ideally on the back or on the belt in a device allowing the user easy carrying. In static use, the air handling unit is not necessarily attached to the body of the user and is placed close to the user. For example office work or work with regular human contact (public transport, counter clerk, etc.).

Air treatment unit (1)

The air treatment unit (1) comprises a removable filter (3) with the possibility of mounting an optional pre-filter (3.1), a radial turbine type air acceleration device (4), a device UV (5) and an autonomous power supply device (6) of the lithium battery type or any other electrical energy storage technology (super capacitor, fuel cell, etc.). The power supply is recharged by solar panel (7) to improve its autonomy.

The air inlet is made up in a row, in the direction of the air flow, of an optional pre-filter (3) of great porosity, of the foam type or synthetic or electrostatic mesh (3.1) in order to block the largest particles . The use of a vortex-type radial pre-filter is also possible. The state of the art of vortex filters is well known and is not the subject of a precise description in this invention. This pre-filter is followed by at least one variable-class main filtration filter adapted to the health situation of the user's environment. For example, it could be ISO Coarse, PM10, PM5, PM2.5, PM1, EPA, HEPA and ULPA.

Depending on the conditions of use, filtration (3) is optional. The device then simply retains the acceleration of the air and possibly the UV and/or possibly the pre-filter. It then becomes a protective device with an air barrier without air filtration or with partial filtration and/or UV treatment of the air.

An air acceleration unit is located downstream of the filtration, it creates sufficient air flow to obtain a protective air curtain at the level of the user's face. The speed to obtain sufficient air protection is at least 2 m/s at the frontal level, this is what we will call below the “frontal wind”. This frontal wind of 2 m/s corresponds to a flow of approximately 400 L/min, i.e. more than 50 times the average respiratory flow at rest of 8 L/min.

The frontal wind of 2m/s is only valid in an air of still environment. If the air in the environment is in motion, either naturally (wind) or artificially (movement of the user), a “relative wind” is created which will counter the frontal wind. This relative wind risks destroying or compromising the aeraulic protection of the device and reducing or canceling its effectiveness. It is therefore necessary to accelerate the “frontal wind” in order to counter the “relative wind” and to maintain a sufficiently strong air curtain.

Thus beyond 8 km/h of relative wind, it has been shown that a frontal wind of at least 150% of the relative wind speed is required to guarantee sufficient air protection.

Example: if the relative wind is 15 km/h (4.2 km/h), an air barrier must be created of at least 15 * 150% = 22.5 km/h (6.3 m/s ) to ensure user protection from airborne elements in the environment.

The frontal wind speed also depends on the breathing rate of the user. At rest, the respiratory flow is around 8L/min but it can increase to 150 L/min in sports mode or even 250 L/min for high-level athletes. In sports mode, it is therefore necessary to multiply the frontal airflow, and therefore the frontal wind speed. A rate correction factor of 5 is sufficient. Thus an athlete, without relative wind, breathing 150 L/min will need a frontal flow of 150*5 = 750 L/min or 12.5 L/s or 4 m/s. This value corresponds to the correction of an equivalent relative wind of 10 km/h.

The adjustment relating to the user's respiratory rate is difficult to automate because it would require biological monitoring of the user's respiratory rate. This is quite intrusive. This adjustment is manual by the user using an adjustment knob on the regulation (9)

The electrical power required to maintain these flow rates essentially depends on the pressure drops, and therefore on the type of main filter. In the absence of a filter, 2 to 5 Watts are enough to maintain a sufficient "frontal wind" if the "relative wind" speed is less than 30 km/h.

With a filter with high filtration efficiency of the HEPA or ULPA type, the filters have more pressure drops, the power required is included, without relative wind, between 10 Watts and 25 Watts.

These relatively low powers allow portable lithium batteries of a few hundred grams and a capacity between 50 and 100 Wh to last several hours of autonomy. Thus a 75 Wh battery (approximately 400 grams with lithium technology) allows 5 hours of autonomy under a consumption of 15 Watts

The self-contained power supply shall include an energy gauge of any type and an audible and visual low residual energy indication alarm to warn the user.

The autonomous power supply is doubled. There are two independent, rechargeable sources of power connected in parallel. They are quickly removable without tools. The mask works equally well on one power supply as it does on two. This allows the rapid change of power supply without interruption of service (continuous service guaranteed). The device requires three power supply units to operate optimally: two in use on the mask and one in reserve.

Recharging of the autonomous power supply is done continuously by solar power during use thanks to an optional integrated solar panel (7) or on the mains electricity network. Mains charging is done directly via the filtration unit or via a dedicated charging station. Mains recharging does not prevent the use of the device, for example, in the event of professional static use (office work).

A removable transparent visor (12) can be installed on the diffuser (2) in order to better channel the frontal air flow in the event of too strong relative wind or in a particularly sensitive or dangerous environment. This visor can be of a type dedicated to the use and the environment and undergo a surface treatment. For example, eye protection visor type for welding work. The main purpose of the visor is to improve the efficiency of the air curtain and to protect the eyes from radiation or splashes. This visor is magnetized or clipped onto the diffuser (2) for quick dismantling.

The filters are easily interchangeable without tools and meet the filtration standards in force corresponding to their nature.

The air treatment unit (1) also includes UV disinfection treatment (5). This UV device consists of different sources of UV of any kind. The aim is on the one hand to improve the sanitary treatment of the air during use by destroying DNA membranes and/or protein disulphide bridges and on the other hand to disinfect the filtration after use. The UV device allows a regenerative mode of the filters. To correctly carry out the disinfection of the filters, the UV sources are placed upstream and downstream of the main filter. It is also necessary to protect users from exposure to UV during regeneration by opaque walls or filtering UV radiation (glass, polymer, etc.).

Depending on the environmental conditions of use, UV can be used without the main filtration or with the prefiltration only. The air from the air curtain is then little or not filtered and only treated with UV.

The UVs are activated manually by the user or come into operation automatically during mains recharging. The UV power required is a few Watts.

Once the air has been treated and accelerated by the processing unit (1) it arrives in the diffusion unit (2), it is a facial air diffuser which will create the aeraulic protective curtain (2.1).

The facial air diffuser (2)

The purpose of the facial air diffuser (2) is to create an air barrier of sufficient size and frontal speed to protect the entire face of the user and particularly the respiratory organs and sensitive to infections: nose, mouths and eyes .

The diffuser creates an air curtain (2.1) of shape adapting to the face, for example of truncated conical shape which traverses and protects the entire face. The shape of the diffuser is a half moon or an arc of a circle between the 2 temples but this shape is not limiting. Any shape that creates an effective air curtain can be used.

To be effective, the thickness of the air curtain is at least 20 mm at the level of the forehead for an arc length of at least 200 mm corresponding to the inter-temple length of the user. By effect of shape and angle of projection of the air flow, the air curtain increases as it descends from the forehead on the face to obtain a thickness of the order of 50- 60 mm at the nose and mouth.

The coanda effect or any other aerodynamic effect can be used to obtain a form of protective air curtain of the laminar flow type. This is to avoid vortices that would mix the filtered air from the front curtain with the air from the environment. The diffuser (2) can have a crown shape or any other shape allowing the creation of the air curtain (2.1). This shape can be, without limitation, prismatic, parallelepipedal, toric...

The control unit (9)

1. Permettre d’allumer, régler et éteindre le dispositif par l’utilisateur
2. Réguler la vitesse du vent frontal par rapport à la vitesse du vent relatif
3. Surveiller l’encrassement de la filtration pour la maintenance
4. Informer l’utilisateur du niveau énergétique résiduel
5. Recharger l’alimentation autonome d’énergie et désinfecter la chambre de filtration et les filtres par UV
6. Suivre la luminosité du rayonnement UV pour la maintenance
7. Communiquer de manière bilatérale ou uni latérale avec des applications informatiques de monitoring ou de réglages de type smartphone ou autres systèmes informatiques et de manière filaire ou non.

Without being exhaustive or limiting, the regulation unit (9) has the following roles, optional or mandatory and which depend on the nature of the use of the device (different commercial variants)

1. Allow the device to be switched on, adjusted and switched off by the user
2. Regulate the frontal wind speed in relation to the relative wind speed
3. Monitor clogging of filtration for maintenance
4. Inform the user of the residual energy level
5. Recharge the autonomous power supply and disinfect the filtration chamber and filters by UV
6. Track UV radiation brightness for maintenance
7. Communicate bilaterally or unilaterally with computer applications for monitoring or settings such as smartphones or other computer systems and wired or not.

The device is turned on with an on/off switch or via the computer application and is adjusted via a user interface of any possible type (screen, button, adjustment wheel, touch screen, etc.).

The user can, for example, without limitation or exhaustiveness: adjust the front airflow manually (sports mode, professional use, etc.), activate the UV, activate the automatic airflow adjustment mode, indicate the operating mode: without filtration or with pre-filter, indicate the type of filter used.

The flow adjustment is carried out by the user with a manual adjustment (8) or automatically thanks to the regulation unit (9) which regulates, among other things, the blowing power, therefore the speed of the frontal wind according to the wind relative. The relative and frontal winds are measured by 2 speed or flow sensors (10 and 11) of any type (anemometric, differential barometric, hot wire, etc.) of the same type or of different types but whose nature is not covered by this patent.

In the case of the use of barometric sensors, the differences between the static pressure and the dynamic pressures make it possible to calculate the respective speeds. A sensor is located in the frontal wind, a sensor in the relative wind and a sensor sheltered from any wind to obtain the static pressure reference making it possible to calculate the frontal and relative wind speeds. A temperature sensor (13) makes it possible to correct the speed measurements or to adapt the speed of the frontal wind to the ambient temperature. This sensor (13) is integrated into the control unit (9).

The automatic flow rate regulation also makes it possible to automatically compensate for the progressive clogging of the filtration.

Filtration clogging is progressive and inevitable. It influences filtration efficiency and energy consumption. The clogging depends on the type of filter installed and above all on the environmental conditions and above all on the particles. It is important to have an idea of the condition and the remaining life of the filtration from a sanitary point of view. The duration of use linked to a comparative measurement of the frontal wind and the electricity consumption of the turbines makes it possible to determine the level of clogging of the filtration via a mathematical algorithm. An audible indication alerts preventively when the filtration needs to be changed. Computer monitoring indicates to the user an estimated value of the residual life in hours or % or longer time unit (weeks, months, etc.).

The monitoring of the energy level is done via the display on the control unit of the display screen type, touchscreen or not, or via a simpler graduated luminous display of the LED type. An audible alarm warns the user in case of low level at several load levels. The computer monitoring indicates a more precise value of the battery capacity as well as, for example but without being limiting: the instantaneous electricity consumption in W, the energy consumed in Wh and %, the residual energy in Wh and %, the number of battery cycles, number of total hours of use of the battery, the state of health of the battery.

Autonomous power charging conditions UV disinfection. Once mains charging has been detected, the UV light switches on to systematically disinfect the filters.

UV disinfection lasts a few tens of minutes and is automatic as soon as the mains is connected unless the main filter (3) is not placed on the device. The UV device (5) is placed upstream and downstream of the main filter in order to ensure surface disinfection of the main filter on both sides as well as of the filtration chamber (1).

The load regulation of energy storage is well known and is not the subject of this patent. If a device other than chemical batteries is used, the charge regulation must be adapted.

Monitoring the UV device can track UV light output which may weaken over time and indicate a possible total failure. A photosensitive UV sensor integrated into the UV device (5) indicates to the user via the regulation a possible failure, whether partial (reduction of radiation) or total. A window or a transparent partition (but filtering UV) also allows the user a visual check.

All device monitoring and setting information can communicate bilaterally with computer software. The communication can be wired via a USB-type connector or wireless, such as for example Wifi, Bluetooth or any other aerial computer data transmission protocol. The purpose is to inform the user of the status of the device and to allow adjustments via an interface other than the control unit. This information can be sent to an internet server for the purpose of preventive maintenance, information and statistics.

This patent is not the subject of the development of this communication and adjustment software which could be the subject of a subsequent patent.

Claims (10)

Facial respiratory protection device characterized in that it comprises means producing a curtain of air blown on the face of the user (2.1), comprising at least one turbine (4) driven by an electric motor, a diffuser (2 ) and an independent power supply (6). Protective device according to Claim 1, characterized in that the air curtain (2.1) at the outlet of the diffuser (2) is at least 20 mm thick and has a flow rate of at least five times the respiratory volume. Protective device according to Claim 1 or 2, characterized in that it comprises a UV treatment means (5). Protective device according to Claim 1 or 2, characterized in that it comprises an air treatment unit (1) in which are removably mounted a means of treatment of the air by filtration (3) and a prefilter. (3.1). Protection device according to Claim 4, characterized in that a UV treatment (5) is present upstream and downstream of the main filtration of the air treatment unit (1) and can be activated by the user. or automatically when recharging from the mains. Protection device according to any one of Claims 1 to 5, characterized in that the autonomous power supply (6) is rechargeable during use by a solar panel (7) and/or on the mains. Protective device according to any one of the preceding claims, characterized in that the blown air curtain (2.1) is created by a turbine-type air accelerator (4) whose flow of air blown on the face of the user is variable and adjustable by the user with a control device (8) or automatically with a regulation unit (9). Protection device according to Claim 7, characterized in that the regulation unit (9) comprises means for adjusting the speed of the air curtain as a function of the speed of the outside wind measured by sensors (10, 11) and /or the ambient temperature measured by a sensor (13). Protection device according to Claim 7 or 8, characterized in that the regulation unit (9) monitors the device and communicates with the user via software. Protective device according to any one of the preceding claims, characterized in that it comprises a transparent (12) or semi-transparent visor for removable, quick-release eye protection.