The present invention generically relates to an integrated system for sanitization and emergency lighting of rooms.
More particularly, the invention relates to an emergency lighting fixture integrating an ultraviolet sanitizing device, wherein air, which is circulated by a fan, passes through a chamber within the lighting fixture irradiated by ultraviolet C-band (UVC) energy, together with, or alternatively, a photo-catalytic reactor activated by ultraviolet UVA-UVB light.
The literature regarding sanitization using UV light is long-standing, and four solutions are typically used for room sanitization:
UVC LEDs, on the contrary, have today a low efficiency, an order of magnitude lower, however as soon as technological evolution will make available more efficient solid state sources (LEDs) it will be trivial to replace the discharge tube with the LED matrix.
UVC LEDs have the advantage of being able to tune the wavelength of the emitted light and possibly to build a matrix composed of several components with different wavelengths; in this way, the sanitizing device could be of type “multiband” and hit more effectively microorganisms different from each other, each LED being tuned to hit more effectively specific links of DNA and/or RNA chains.
On the other hand, the operating principle of a photo-catalyst is as follows: a semiconductor material, such as titanium dioxide (TiO2), is irradiated with light suitably tuned to the band-gap characteristic of the semiconductor itself. Electrons excited by the incident photons move into the conduction band, leaving gaps in the valence band of the semiconductor.
On the surface of the catalyst, electrons can thus combine with electron “acceptor” elements in a reduction reaction, while gaps can combine with electron “donor” elements in oxidation reactions.
Overall, oxidation-reduction reactions result in three mechanisms for deactivation of chemical species and pathogens:
The effectiveness of photo-catalysts depends on their chemical and physical characteristics, in particular on the morphology of the surface on which the chemical reactions take place; for example, the effective active surface, with the same size (porosity), and the size of the grains that make up the active surface are important.
Photo-catalysis has been shown to disinfect a variety of pathogens, including bacteria, fungi, and viruses. The mechanism of deactivation is based on the interaction of ROS species with the cell membrane of microorganisms, which is compromised and the microorganisms killed.
In the photocatalysis system implemented by this integrated system, air, circulated by a fan, passes through a photo-catalytic cell inside the device; the oxidation and reduction reactions that take place inside the chamber purify the air by transforming some of the chemicals present and sanitize the air by deactivating viruses and bacteria, as well as remove unpleasant odors from the air itself.
The device can also optionally contain an ozone generator placed downstream of the photo-catalytic cell, which can be turned on by a timer or by a radio remote control to be activated only when people are absent; for this purpose, the device also integrates a people presence sensor (for example, a microwave radar or a PIR sensor) to turn off the ozone generator when people are detected present.
With respect to emergency lighting of rooms and sanitization of rooms, it is currently contemplated to install two devices, such as an emergency lamp and an air purification and sanitization device; in the case of using ozone, it is further necessary to provide for the installation of three devices, namely an emergency lamp, an air purifier and an ozone generator.
The purpose of the present invention is to provide an integrated system for sanitizing and for emergency lighting of rooms, which allows in a single mechanical structure to provide adequate safety lighting of rooms in the event of a blackout and which, at the same time, contributes to the purification and sanitization of the air of a room conveyed into the system, by means of the germicidal action of an integrated UVC source and/or a photo-catalytic reactor. Another purpose of the present invention is to produce an integrated system for the sanitization and emergency lighting of rooms, which allows to sanitize the air in the rooms in which it is installed, deactivating a certain percentage of pathogenic organisms at each cyclic passage of the air itself inside the system. A further scope of the invention is to realize an integrated system for the sanitization and emergency lighting of rooms, which allows reducing the diffusion of bacteria, fungi and viruses in the air and at the same time to improve the air quality by reducing the quantity of volatile organic compounds. A further purpose of the invention is to realize an integrated system for sanitizing and emergency lighting of rooms, which also allows carrying out a complete sanitization of the environment in the absence of people.
These and other purposes are achieved by an integrated system for sanitizing and for emergency lighting of environments, according to the appended claim 1. Other detailed features can be found in the dependent claims.
Advantageously, the present invention consists of integrating an air sanitizing system using UVC radiation sources and/or photo-catalytic reactor within an emergency lighting fixture, with which advantageously they share housing and internal electrical control and operating parts.
The new system, being bound to the lighting positioning, takes advantage of this constraint by placing the purifier and/or sanitizing device in the most suitable positions for the treatment of the air inside the premises; in fact, the emergency lamps are always installed high up, in optimal positions for the diffusion of light and consequently also for the treatment of the air.
The new system therefore includes an emergency luminaire containing an internal chamber illuminated by a UVC source and/or a photo-catalytic reactor (consisting of a micro-catalyst and a UVA-UVB source), through which air circulation is forced by a ventilation system.
Conveyed air carries aerosols that include pathogenic microorganisms (bacteria, viruses, and fungi) and volatile chemical compounds VOCs (Volatile Organic Compounds).
Photo-catalysis and/or UVC radiation sources, at wavelengths ranging from approximately 250 nm to approximately 280 nm (having the greatest germicidal capacity), are capable of neutralizing many chemical species and pathogenic organisms.
The system is sized so as to treat every day one or more times the entire volume of air in the environment in which it is installed by supplying the air in the environment with one or more doses of germicidal radiation; it can optionally contain an ozone generator, which can be activated by the user, and which is protected by automatic mechanisms to prevent it from being turned on in the presence of people in the environment in which the system is installed.
In particular, the ozone generator, which can be integrated in the emergency lighting fixture, can be of two types
Finally, the system is very compact, as integration into the emergency lamp allows multiple safety functions to be combined within the same device, reducing the proliferation of different objects and devices within buildings.
Additionally, the integrated system has a lower cost than the sum of the separate devices (emergency lamp, photocatalysis and/or radiation purifier, ozone sanitizing device), since it uses some common parts.
Further purposes and advantages of the present invention will be more clearly understood from the following description of preferred, non-limiting embodiments of the integrated room sanitizing and emergency lighting system according to the present invention, and from the appended drawings, in which:
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In order to facilitate understanding of the figures, the represented embodiments alternatively comprise the photocatalytic reactor or the UVC radiation source, but the description is intended to be extended also to embodiments of the invention comprising both, as moreover already fully specified in the introductory section of the present application.
With reference to the figures mentioned, the integrated system according to the present invention includes an outer housing 23, made, for example, of a technopolymer plastic, within which the following parts are incorporated:
A direct air flow F from right to left is shown in the figures, but the direction can be reversed from left to right depending on the specific sizing of the duct and sanitizing chamber 19.
In any case, the air flow F is preferably oriented so as to avoid sending the ozone created by the optional generator 32 into the area of the chamber 19 occupied by the UV sources or the photo-catalytic cell.
The UVA-UVB light source of the photo-catalytic reactor or photo-catalyst 20 preferably comprises UVA-UVB LED plates 20A emitting in the bands from 300 to 450 nm, depending on the characteristics of the catalyst. The catalyst may be made from titanium dioxide (TiO2) or other materials, such as ZnO, CeO2, ZrO2, SnO2, WO3.
The photo-catalytic reactor 20 described and illustrated in the attached
The UVC light source may comprise a low-pressure mercury discharge lamp (shown in detail in the attached
To maximize the energy dose that the conveyed aerosol absorbs at each crossing of the chamber 19 illuminated by the UVC source, sizing is done according to the following criteria:
In fact, the germicidal dose Eg (which dimensionally corresponds to the UVC energy density to which microorganisms are subjected) is expressed in J/sqm and is obtained as the product of the radiant power Pg (W/sqm) in the illuminated zone and the time T of transit through the zone itself, i.e. Eg = Pg x T.
It is evident that the greater the illuminated volume of chamber 19, with the same air flow, the greater the time of transit by the aerosol.
From the scientific literature we find indications of minimum necessary doses between a few J/sqm and 100 J/sqm, depending on the susceptibility of viruses and bacteria that we want to kill.
Using lamps from 5 to 20 W as UVC sources, average power densities of a few tens of W/sqm are typically obtained in the illuminated inner chamber. Furthermore, considering, for example, a transit time on the order of 1 second, the doses are therefore several tens of J/sqm.
For the sizing of the fan 22 in the typical size of an emergency lamp (300 x 150 x 50 mm), it is advantageous to have airflows between 1 and 5 cubic meters per hour, so as to ensure the complete air exchange of a room one to a few times per day.
At the same time a reduced flow offers the advantage of a high level of silence of the device and the maintenance of a high dose of radiation at each transit of the chamber 19; in fact, a low intensity air flow is equivalent to a high transit time of the chamber 19.
The sanitizing chamber 19 is preferably made of metal with reflective inner walls so as to minimize any shaded areas and to ensure that the aerosol is treated by the UV light source 200, 250 and/or the photocatalytic reactor 20 during the entire residence time in the chamber 19 itself, in order to enhance the sanitizing effect.
Suitable shade baffles 16 are positioned in the air inlet and outlet ducts, which prevent the escape of UV radiation from the chamber 19 to the outside, while at the same time ensuring the lowest possible pressure drop in the air duct. Appropriate separating plates 33 may also be introduced between the UV source (UVC light source 200, 250 and/or photo-catalytic reactor 20) and the ozone generator 32 when present, to avoid contamination or electrical discharge.
Any internal plastic parts, such as fan blades 22, are protected from UV radiation by staggered metal grids 21, which limit the intensity of UV light directed at such parts (which could be responsible for premature aging of such materials).
The apparatus may advantageously incorporate a pyroelectric sensor 25 for the presence of people, as an alternative to a microwave radar 24 for the same function. In the event that it is desired to increase the safety of detecting people in the environment, the two sensors 24, 25 may both be present and used in an “OR” mode for inhibition of the ozone generator 32, if present, following detection of people by only one of the two sensors 24, 25.
Advantageously, the system also incorporates an air quality sensor 31, positioned inside the chamber 19 and, in particular, near the air inlet vents 17, capable of functioning and performing measurements correctly even with the fan 22 turned off; the sensor 31 measures the average concentration of volatile organic compounds VOC or VOX, (acetone, methanol, ethanol, hydrocarbons, heptanes, toluene, xylene, etc.).
The sensor 31 may be activated to turn on the photo-catalytic reactor 20 automatically when the concentration of VOCs exceeds a certain value in the environment, which also typically corresponds to the prolonged presence of people in a room that is not well ventilated.
The block diagrams in
Specifically, the microprocessor 28 of the electronic circuit 14 governs the operation of the entire system and coordinates the various subsystems as follows:
The functioning of the integrated system for sanitization and emergency lighting of rooms is basically the following.
In the presence of 230Vac power supply, once installed, the system activates the photo-catalytic reactor, through the lighting of the UVA-UVB LEDs 20A, and/or the UVC source 200 and the fan 22. in order to start the sanitizing and air purification function.
Simultaneously, the battery 18 related to the emergency lighting is charged and maintained in a charged state.
In versions that include the ozone generator 32, the user can activate this function via a BLE radio command given by a smartphone equipped with an appropriate application, or via an IEEE802.15.4 radio command from a remote management system of centralized emergency lighting control, possibly cloud-based (e.g., the Beghelli® nuBe).
Alternatively, the ozone generation function can be controlled by a daily or weekly timer programmed during system configuration.
In any case, the ozone generation function is not activated as long as the presence of people is detected by one of the sensors 24, 25 present in the room.
In order to avoid that in any case the accumulation of ozone at small intervals can be harmful, the generation function is activated only if the presence of people is not detected for at least 60 minutes and, in case of detection of the presence of people, the generation of ozone is immediately stopped and the acoustic signaler (buzzer 38) with fast intermittence (2 Hz) is activated to indicate to leave the room or to ventilate.
When the ozone generator 32 is turned on, the signaling LED 15 flashes with red color at high frequency (2 Hz).
It is possible to configure the product in such a way that a beep is also emitted by the buzzer 38 every 2 seconds (0.5 Hz), in the absence of people present, to signal the emission of ozone.
As soon as a sensor 24, 25 detects the presence, the beeper 38 increases the frequency to 2 Hz to insistently signal the danger.
The two versions of ozone generator 32 described in the present invention differ in that one (
Ozone is useful for sanitizing the entire environment, including the surfaces of objects placed in the room that otherwise would not be sanitized by the airflow through the chamber 19.
The ozone generated becomes itself a germicidal agent able to propagate in the environment, acting on the surfaces and on the objects it meets.
The purification and/or sanitization mode can be configured via the BLE radio interface with an APP from a smartphone or tablet, or from a remote management system for centralized emergency lighting control, possibly cloud-based (e.g., Beghelli® nuBe).
The speed of the fan 22 can be defined by choosing, for example, between a slow speed corresponding to lower airflow F (and therefore less frequent air exchange) and quieter operation, or a higher speed with higher airflow, but higher fan 22 noise.
It is also possible to choose the daily sanitizing switch-on cycle, for example between “always on”, “on for 4 hours a day” or “on for 8 hours a day” or the automatic mode managed by the air quality sensor 31.
Finally, it is possible to determine the modes and times when the ozone generator is switched on 32.
The default mode of operation for the UVC source with discharge tube 200 is typically with 8-hour daily turn-on to maximize the life of the tube itself, which is on the order of 15000 hours, so that it has a useful life of at least 4-5 years. The communication interface also allows the emergency mode of operation to be configured in accordance with the customs of emergency luminaires.
In the absence of the main power supply, the sanitizing function is turned off and the battery 18 is used to power the light source (LED) of white light 13 for a defined time.
The sanitizing function is kept on when mains power is present according to the cycle selected by the user.
The low pressure mercury discharge tubes or lamps 200 have a UVC emission efficiency curve that is significantly dependent on the operating temperature of the tubes, as shown in the attached
In this regard, a temperature sensor 240, located on the discharge tube or lamp 200, is advantageously employed in the system.
The microprocessor 28 measures the temperature and, acting primarily on the driving power of the discharge tube or lamp 200, maintains the temperature at the optimum value for having the maximum UVC power emitted, causing the tube or lamp 200 to work at the optimum point (in the case of the attached
If necessary, the microprocessor 28 also acts on the speed of the fan 22 to adjust the temperature to the optimum value; this function allows the maximum germicidal sanitizing efficacy to be maintained under any operating environmental conditions.
As mentioned, the system can also be equipped with a sensor 11 for measuring ambient light, which has the purpose of identifying the day/night cycle and activating, for example, the sanitizing function during the day and turning it off during the night, according to the set cycle.
In this way, maximum silence is guaranteed at night (fan 22 off) and the system is automatically activated only during daylight hours.
Alternatively, the system can be configured with different cycles according to specific user requirements and/or always synchronized to the day/night cycle. As an alternative to the ambient light sensor 11, the microprocessor 28 can be equipped with an astronomical clock, calibrated at the factory with a small battery to operate with precise knowledge of the time of day and time of year and thus activate the most appropriate sanitizing cycle moment by moment.
In a more complete and versatile realization, the device also incorporates the air quality sensor 31 based on the measurement of the concentration of VOC to automatically activate the sanitizing cycle when a certain overall concentration is exceeded.
In this way the sanitizing device is automatically activated in the presence of occupants of the room in which it is installed when the pre-set air pollution levels are exceeded, exerting its germicidal sanitizing action when people are present in the environment.
Regarding the ozone generation function, the system generates a radio command when the ozone generation cycle has been completed; this radio command is sent to a relay actuator and the radio relay turns on a fan external to the system, which performs the air exchange in the room to remove the ozone before the people come back in. The control is timed by the system, and the time the external fan is turned on is configurable via the radio interface itself.
In a further different mode of operation, the ambient light sensor 11 is used as a sensor for the movement of people within the same room, based on the detection of sudden changes in ambient brightness; in this way, the microprocessor 28, by means of the light sensor 11, is able to detect the entry of an occupant into the room and activate a sanitization cycle in correspondence to this event and then put itself in a state of quiet in the absence of movement detected by the light sensor 11 itself.
The information from the air quality sensor 31 and the light sensor 11 can finally be used in synergy with each other to make the sanitization strategy even more refined.
In essence, a “smart” sanitizer with low-cost sensors that are completely non-invasively integrated into the emergency lighting fixture is thus realized.
The invention thus conceived and illustrated is susceptible to modifications and variations, all of which fall within the inventive concept of the appended claims. Furthermore, all details may be replaced by other technically equivalent elements.
Finally, the components used, provided that they are compatible with the specific use, as well as the dimensions, may be any according to the requirements and the state of the art.
Where features and techniques mentioned in the claims are followed by reference marks, such reference marks have been included for the sole purpose of increasing the intelligibility of the claims and, accordingly, have no limiting effect on the interpretation of each element identified by way of example by such reference marks.
Number | Date | Country | Kind |
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102020000008248 | Apr 2020 | IT | national |
102020000012892 | May 2020 | IT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IT2021/050113 | 4/15/2021 | WO |