Claims:We Claim,
1) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air comprising; an outer shell (101), an Ozone generating unit (105), a system to control disinfection and purification of environmental air (108) within an air duct (200), a power supply unit (110) and a controller (107) wherein the said disinfection and purification of air is done by the generation of a barrier discharge in the air in the form of a Cold Arc Plasma.

2) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said outer shell (101) comprises of perforations having diameter in the range of 1mm to 15 mm.

3) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the configuration of the said outer shell (101) is selected from at least one from the group comprising of circular, triangular, square, rectangular, pentagonal, hexagonal, heptagonal, octagonal or arbitrary cross-sectional shapes, sizes, shell lengths.

4) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said outer shell (101) is made up of a material selected from at least one from the group comprising of metals, alloys, non-metals or composite materials.

5) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said Ozone generating unit (105) comprises of one or more Spark Plugs (102) for generating a Cold Arc Plasma.

6) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said spark gap (116) of the Ozone generating unit (105) is in the range of 1 to 7 mm.

7) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 5, wherein the said one or more Spark Plugs (102) for generating a Cold Arc Plasma are arranged in a combination opted from linear row(s) and/or column(s) or arbitrary geometric configurations / patterns.

8) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 5, wherein the said one or more Spark Plugs (102) for generating a Cold Arc Plasma are electrically operated individually or in a connected series, parallel or series-parallel configurations.

9) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said system (108) comprises of one or more sensors (106) for monitoring level of Ozone present at distant end of the device or at various distances from the device in the duct (200) and communicating with the said controller (107).

10) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said controller (107) auto cuts off the said system (108) when the output value of the said sensor (106) for Ozone is greater than the set value.

11) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said controller (107) auto cuts off the said system (108) when one of the sensors placed at the entry of the duct (200) detects the presence of an inflammable component in the environmental air.

12) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 11, wherein the said controller (107), after detecting an inflammable component, triggers an audio-visual alarm and also stops the flow of air into the duct (200).

13) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said controller (107) engages and disengages one or more spark-plugs (102) based on the input of airflow entering the said duct (200) which increases the disinfection and/or electrical efficiency of the said system (108).

14) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said power supply unit (110) is a high voltage pulsating unit generating an AC voltage in the range of 2-50 KV RMS.

15) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said power supply unit (110) is a high voltage pulsating unit generating an AC voltage oscillating with a frequency upto 30 KHz.

16) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 15, wherein the AC voltage generated by a high voltage pulsating unit across the spark gap (116) can be in form of sinusoidal or non-sinusoidal repetitive pulse of short durations.

17) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 14, wherein the means to generate high voltage is selected from at least one from the group comprising of half wave rectifier, full wave rectifier, voltage doubler circuits, voltage multiplier circuits, Cockcroft-walton circuits, van de graaff generators, voltage transformer based boosting circuits, non-transformer based solid state boosting circuits, capacitor based boosting circuits.

18) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said device is placed in a duct (200) in such a manner that it is located anywhere within the said duct (200) at least at a distance of its length away from the entry and exit of the said duct (200).

19) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said device is a modular standalone device which can be retrofitted in a duct meant for at least one from the group comprising of HVACs, AHUs, Air Conditioners, Air circulators, Air-purifiers, Air-disinfecting systems or built-in environments such as indoors, industrial spaces, bio/ pharma/ food and beverage processing units, hospitals / healthcare facilities, commercial and office spaces, homes or automobiles.

20) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said device completely disinfects the air entering into any facility through a channel duct by removing the VOCs, reactive components, Microorganism including viruses and bacterias with an efficiency of 99.99%.

21) A device (100) for generating Ozone using Cold Arc Plasma for disinfection and purification of air as claimed in claim 1, wherein the said device is integrated with Internet of Things which enables real-time monitoring and controlling of the said system for purifying the environmental air entering the said duct.

Dated- 30th July 2021 Signature of the Agent
Rajat Chaudhary IN/PA-3136
, Description:The following specification fully and particularly describes the invention and the
manner in which it is to be performed.
FIELD OF INVENTION.
[0001] The field of invention is based on the generation of Cold Arc Plasma (spark Plasma) to produce Ozone that can be used for disinfection and purification of supplied air. This can be directly embedded into the air-ducts of the existing or new facilities/buildings.
USE OF INVENTION
[0002] This invention is related to an affordable and effective indoor air purification system to disinfect air which is the major carrier of bacteria, virus (including Corona virus and other category of such viruses), Volatile Organic Compounds (VOCs) and particulate matter (PMs).
BACKGROUND AND PRIOR ART
[0003] The pandemic has been a force driving the need for evolution towards a future where we can save living entities from harmful bio-hazards. Air borne diseases have become a common phenomenon and the amount of risk they contain is well established by the recent COVID pandemic. In metropolitan cities, indoor and outdoor air pollution have become a big challenge. They hold significant levels of Volatile Organic Compounds (VOCs), Virus and Bacterial loads and other harmful constituents which need to be neutralised
[0004] Due to the emissions of VOC and particulate matter from household utilities, indoor air is polluted between two and five times more than outdoor air; one can understand the importance of indoor air quality improvement. Since people spend nearly 90% of their time indoors (at workplaces and at homes), this should greatly concern us. Data shows that 72% of chemical exposure occurs in the home, which is assumed to be the safest zone, but which is the most hazardous. It is also to be noted that people spend more than 40 hours per week in their workplaces, leading to significant exposure to various pollutant mentioned earlier.
[0005] Duct systems pollute the passing air when they are unclean, both new and used. Besides a pollution source, ducts may also be a reason for the loss of ventilation efficiency. Most ducts in Europe are leaky and thus increasing the energy use for ventilation [35]. Typical parameters clarified in the literature study on air duct hygiene were the surface concentration of dust and microorganisms (fungi and bacteria) present on the bottom of the duct; but also, the quality of the supply air, in terms of particle concentration, microorganisms, TVOC (Total Volatile Organic Compounds) and odour. Due to the long operation time (up to several years) and due to the large inner surface area of ventilation ducts, estimated to be about 10 % of the floor area in office buildings [36], a significant amount of dust may accumulate mainly on the bottom surface of ventilation ducts.
[0006] The dust layer may promote the survival and growth of microorganisms and they release metabolic products, spores or even viable cells, into the supply air, causing health problems to occupants of the buildings. In general, the particle concentration in the air (either gravimetric or number related) is the basic parameter influencing the dust surface concentration. Other parameters, such as flow velocity and duct geometry, merely affect the deposition rate, i.e., the fraction of airborne particles that settles on the duct surface. As a consequence, it is obvious that if more particles pass the ventilation filters and enter the duct system, the higher the surface dust concentration. The major question to be answered with respect to the pollution effect of ducts is: What is the effect of air velocity (airflow), duct length, manufacturing residues and dust.
Effects of air pollution from ducts
[0007] Some health effects may show up shortly after a single exposure or repeated exposures to a pollutant. These include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Such immediate effects are usually short-term and treatable. Sometimes the treatment of polluted air person's exposure to the source of the pollution, if it can be identified. Soon after exposure to some indoor air pollutants, symptoms of some diseases such as asthma may show up, be aggravated or worsened.
[0008] The likelihood of immediate reactions to indoor air pollutants depends on several factors including age and pre-existing medical conditions. In some cases, whether a person reacts to a pollutant depends on individual sensitivity, which varies tremendously from person to person. Some people can become sensitized to biological or chemical pollutants after repeated or high-level exposures.
[0009] Certain immediate effects are similar to those from common cold or other viral diseases, so it is often difficult to determine if the symptoms are a result of exposure to indoor air pollution. For this reason, it is important to pay attention to the time when and place where the symptoms occur. If the symptoms fade or go away when a person is away from the area, for example, an effort should be made to identify indoor air sources that may be possible causes. Some effects may be made worse by an inadequate supply of outdoor (fresh) air coming indoors or from the heating, cooling or humidity conditions prevalent indoors.
[0010] Other health effects may show up either years after exposure has occurred or only after long or repeated periods of exposure. These effects, which include some respiratory diseases, heart disease and cancer, can be severely debilitating or fatal. Hence, it is prudent to try to improve the indoor air quality in workplaces and at homes even if symptoms are not noticeable.
[0011] While pollutants commonly found in indoor air can cause many harmful effects, there is considerable uncertainty about what concentrations or periods of exposure are necessary to produce specific health problems. People also react very differently to exposure to indoor air pollutants. Hence, it is important to treat and disinfect the air that is being circulated, recirculated or fed freshly from outside into the closed and/or indoor environments.

Various methods available for purifying the air
Air Purifiers
[0012] When it comes to Indoor air quality improvement, air purifiers are the best options available. An air purifier will help people suffering from allergies or frequent colds, make them breathe easier and work or sleep better. High-quality, in-home air purification systems kill up to 99% of germs, pollen, and mold captured. It also fights hard and effectively, against many common pathogens. Installing an air purifier gives peace of mind and the freedom to breathe deep, knowing that the air we breathe is clean.
[0013] There are many types and sizes of home air cleaners in the market, ranging from relatively inexpensive table-top models to sophisticated and expensive whole-house systems. Some air cleaners are highly effective at particle removal, while others, including most table-top models, are much less so. Air cleaners are generally not designed to remove gaseous pollutants. Also, these are unwieldy and inefficient for large buildings.
[0014] Another important factor in determining the effectiveness of an air cleaner is the strength of the pollutant source. Table-top air cleaners, in particular, may not remove satisfactory amounts of pollutants from strong nearby sources. People with a sensitivity to particular sources may find that air cleaners are helpful only in conjunction with concerted efforts to remove the source.
UV Lamps
[0015] The thought of mold and bacteria growing on air conditioning and heating units, becoming airborne, and filling the living space is unnerving. And while keeping unit clean and installing an air purifier will definitely help eliminate that danger, going a step further isn’t a bad idea. UV lamps were designed to successfully prevent the growth of mold and bacteria in homes and work environments. If there is any mold or bacteria growing in or around the AC coil, the UV lamp will kill it, keeping the occupants safe from any exposure.
Clean or Replace Air Filters Regularly
[0016] It’s important to use high-quality air filters and to change them regularly. The air filter keeps the air cleaner, and keeps debris and dust out of the air ducts, and traps dust and allergens before they escape into the air that circulates indoors. Dirt and debris build up in the filters over time. Hence, cleaning or changing the filters periodically will help provide clean air for breathing all times.
Ionization technology
[0017] UV lights kill contaminants on surfaces. Oxidation and ionization air purifiers can do more: they destroy particles in the air within the HVAC system and clean the air throughout the occupied space.
[0018] Air purifiers that use oxidation and ionization technology are commonly used in healthcare facilities and food processing plants, and can significantly increase indoor air quality in other commercial, residential, and public sector spaces.
[0019] There are a number of different types of technology, including photo-catalytic oxidation (PCO) and bipolar or Plasma ionization, that work in different ways to target and destroy airborne particles. They are very effective at removing viruses, bacteria, mold spores, VOCs, and even odours from the air, and doing so very quickly. In fact, the devices can reduce sneeze germs by 99% in the time a sneeze can reach three feet.
[0020] These devices produce friendly, natural oxidizers that get distributed throughout the workspace, not only within HVAC system. The technology takes oxygen molecules from the air and converts them into charged atoms that then cluster around tiny particles, surrounding and deactivating harmful substances like airborne mold, bacteria, allergens, and viruses.
[0021] Reference can be made to CA2307590A1, which discloses a Plasma Ozone generator, in particular of the kind with a mean to high Ozone production capacity, comprised between 1 and 15 kh/h. Ozone is an allotropic form of oxygen and which is a powerful oxidator and performs its functions mainly in three ways:
- direct oxidation by addition onto the substratum by means of an ozonolysis;
- direct oxidation on the substratum due to the loss of one oxygen atom;
- catalytic oxidation due to the effect of the oxygen in the ozonized air.
[0022] Reference can be made to CN10367309 1B which discloses about a oxygen-rich air purifier for treating air haze and odour and removing carbon dioxide and infectious disease particles. The Ozone in the air purifier oxidizes organic or inorganic nitrogen oxides, sulfides, amides, amines, and peculiar smells in the air. Dead disease-source microorganisms, unreacted Ozone decomposes into oxygen to enrich the air; the water in the air purifier absorbs and automatically separates nitrogen oxides, nitrates and sulfates generated by sulfides, and precipitates dust particles in the air; The saturated calcium hydroxide emulsion in the purifier absorbs the purified carbon dioxide to generate calcium bicarbonate.
[0023] Reference can be made to JPH07227322A, which discloses about a sterilization locker for sterilizing an object to be sterilized contained in a locker with Ozone. The Ozone generation unit is separated from the machine room containing the generated Ozone generation unit, and the Ozone generation unit is connected to an Ozone blowing pipe that guides the Ozone generated in the unit and blows it out from the upper part of the locker room. A fan is provided, an exhaust louver is provided in the machine room, an external Ozone killer for introducing external air is provided in the locker room, and air in the locker room is introduced between the locker room and the machine room. An internal Ozone killer is provided for exhausting and decomposing Ozone.
[0024] Reference can be made to CN104588209B which discloses about a method for removing fine particles in the air under household environmental conditions comprising the following three steps;
a) Providing an air passage for purifying the flowing air to be treated in the pumping passage.
b) In the air passage, along the gas flow direction of the air to be treated, a positive and negative high voltage pulse charging region, an electrostatic condensation zone under the alternating electric field, a dust collecting region, a Plasma disinfecting region and a negative ion region are sequentially disposed.
c) In the positive and negative high voltage pulse charging regions, first to third ground plate electrodes are disposed of, the longitudinal axes of the first to third ground plate electrodes are parallel, the positions are juxtaposed, and the air channels are divided into parallel, arranging a positive high voltage pulse charging region and a negative high voltage pulse charging region, respectively, between the first and second ground plate electrodes and between the second and third ground plate electrodes, respectively, a positive and negative linear corona discharge electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Hereinafter, the system according to a preferred embodiment of the present invention is illustrated by referring to the attached drawings.
[0026] Figure 1: Perspective view of the air purification device
[0027] Figure 2: Assembly of the Spark Plugs
[0028] Figure 3: Illustration of the air purification process
[0029] Figure 4: Installation of air purification device
[0030] Figure 5a: Illustration of different zones of an air purification control system
[0031] Figure 5b: Generic installation of purification device inside the duct
[0032] Figure 6: Graphical representation of relation between Power consumption and velocity
[0033] Figure 7: Graphical representation of relation between Ozone concentration and air velocity
[0034] Figure 8: Detailed flow chart of the device functioning
[0035] Figure 9: Outlay of the device functioning
PROBLEM TO BE SOLVED.
[0036] Thus from the prior-art survey, we know that over the last few decades there have been various efforts from technology organizations, product companies, governments and environmental standards agencies to bring forth clean air for the population at large. Significant advances have been made in technologies used in cleaning air in closed environments like workplaces, commercial buildings and homes. Efficient filters and air purifying mechanisms are being implemented in air coolers, air conditioners and larger HVAC systems in offices and buildings. Above mentioned technical solutions from prior-art are largely used to remove Particulate Matters (PMs) of various sizes in the air, whereas pollutants in the form of Volatile Organic Compounds (VOCs) and Micro-organisms are not effectively neutralized. Broad spectrum purification and disinfection of supplied air from these VOCs and Micro-organisms (including viruses) is still a challenge and has neither been implemented with a full complement of purification and disinfection mechanisms nor have been completely successful. Further, due to the recent spread of the Covid pandemic across the world, this challenge of purifying and disinfecting breathing air in closed environments like large offices, workplaces, factories, processing units, commercial buildings, hospitals, etc., has become important for us to address and create safer breathing environment free of micro-organisms, viruses, etc., in addition to the usual PMs and VOCs. Therefore, this invention is motivated by this dire need from society to keep people healthy and free from infection in their workplaces and homes.
OBJECT OF INVENTION
[0037] Main objective of the invention is to provide on-line, fast and effective purification and disinfection of air in a safe manner, within the air-supply ducts before the purified air enters the human-occupied workspaces, living spaces or built-environments.
[0038] Another object of the invention is to provide a standalone unit which is capable of generating Cold Arc Plasma to produce Ozone upto a level necessary for the disinfection and purification of the air inside the duct system.
[0039] Another object of the invention is the generation of Cold Arc Plasma by using conventional automobile Spark Plugs, thereby realizing an affordable (low-cost), easy to install and maintainable system
[0040] Another object of the invention is to smartly consume all the Ozone generated within the duct, by use of one of several methods available such as; HP UV Lamps/LED’s, Activated Carbon filters, Copper netting mesh, a mixture of copper oxide and manganese oxide, Platinum/Palladium catalysts or thermal destruction methods
[0041] Another object of the invention is to provide a system for detection of Ozone levels beyond 0.1 ppm and activating appropriate safety measures.
[0042] Yet another object of the invention is to have the capability to be retrofitted in any existing HVAC duct and other air-supply systems.
SUMMARY OF THE INVENTION
[0043] The proposed invention is a meticulously designed and lucidly integrated solution for disinfection and purification of air and protecting important centres and workplaces of any organisation. This device can be easily integrated with minimal circuitry and can ensure that air coming from the external environment is made free of any discrepancies or pollutants which can prove damaging to a living being. It has not got any harmful effects upon any living being as all the parameters have been maintained well below the permissible limits by OSHA. It is integrated with a small sensory device that will ensure the device’s safe and efficient functioning. The disinfection of air with Ozone will bring down the harmful constituents not limited to VOCs/Viruses/Bacterias and others. The efficiency in disinfecting these harmful constituents is to 99.99 percent. The Ozone produced is sufficient enough to neutralise these components.
[0044] Our main aim is to bring an innovative, affordable (low-cost) and effective indoor air purification system to disinfect air which is the major carrier of bacteria, virus (including Corona virus and other category of such viruses), Volatile Organic Compounds (VOCs), particulate matter (PMs) and other such significant pollutants. These substances are usually inhaled through the air as a medium which can cause various respiratory diseases, contagious infections from co-workers, spread of epidemics / pandemic and cause serious health issues to people. This situation becomes more acute, for example, when it comes to the Modular Operation Theatres (MOT) and Control Rooms. Modular Operation Theatre needs to be completely free of any load of virus and bacteria as well as other harmful components. Similarly, Control Rooms are the heart of any organization, they need to be kept functional even during a case of pandemics and emergency of a biological hazard. Also, special care needs to be taken for the people that are housed by facilities such as hospitals, large IT parks / offices, commercial offices, malls, movie halls, airport terminals / lounges, metro stations, etc.
[0045] We have brought out a system based on Cold Arc Plasma Cluster to purify and disinfect air of its harmful constituents. It is a system based on generation of Cold Arc Plasma (spark Plasma) and can be directly embedded into the air-ducts of the existing or new facilities of above-mentioned built-environments. The Cold Arc Plasma interacts with the air flow to produce Ozone in a certain desired quantity (7-8 ppm) in the neighbourhood of the Plasma arc devices. It is well known that Ozone is an excellent disinfectant and is capable of killing microbes/viruses/VOCs and other such harmful components in the air. Ozone generated in the vicinity of the Cold Arc Plasma gets in contact with the various harmful microorganisms (bacteria, virus) and VOCs in the air and neutralizes them by reacting with these components. Since Ozone above a certain level of concentration is harmful for the human consumption, our system is designed in such a way that by the time air comes out of the air-duct into the work-place where people occupy and work, the residual Ozone gets neutralized to below permitted OSHA limit (0.1 ppm). Thus, all the loads of viruses, bacteria and VOCs in the air are neutralized to a level of 99.99% within a matter of few seconds.
[0046] This device does not need any additional installation requirements and can be directly embedded into the existing air-duct systems. The purified and supplied air is monitored at the outlets for the parameters of Ozone concentration and feedback for managing and controlling the Cold Arc Plasma arcs. This data is further continuously logged through a cloud software based upon the idea of Internet of Things (IoT) devices. Such data can be further used to fine-tune the device and increase or decrease the number of Cold Arc Plasma arc nodes.
[0047] Our innovative system is made very simple that no other additional requirement is needed for the device and it can operate with a simple on/off switch. We have designed this device to be integrated with any location which have an established HVAC system. This system can be used in shopping malls, hospitals, control rooms, institutions and organizations as mentioned earlier. These examples are just suggestive of the places this can be implemented but the application can be very wide in other areas like food and beverage industries, pharma production units and the like.
DETAILED DESCRIPTION OF THE INVENTION –
[0048] Instant invention is an air purification and disinfection device (100) based on the system of Cold Arc Plasma. This Cold Arc Plasma is generated using an automotive IC engine’s Spark Plug with a gap of 3 mm. A Spark Plug is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel-air mixture by an electric spark, while containing combustion pressure within the engine. Spark Plug has basically three important parts; an insulator, a ground electrode and another second electrode which is kept at pulsating high voltage. Insulator is a ceramic material sintered alumina (Al2O3), tip of the central electrode which is kept at high voltage, is made up of an alloy combination of copper, nickel, chromium or noble metals, the lateral electrode which is grounded is made up of nickel alloy. This Spark Plug is connected to a high voltage pulsating power supply unit operating at the range of Very Low Radio Frequency (10-30 KHz), generating and applying AC high voltage (15-20 KV RMS) across the spark gap to produce sustained Cold Arc Plasma.
[0049] The Cold Plasma thus generated in a sustainable manner produces Ozone in a desired quantity, which will accomplish the disinfection of supply air in the duct. This generation of Ozone in a desired quantity from the device leads to the destruction of all the harmful components (VOCs/Viruses/Bacteria’s/other such reactive components) which may be present in the air. Ozone has a disinfection property as it is a strong oxidizing agent. As soon as it comes in contact of such reactive species, it reacts with them and oxidizes them to neutralize their harmful impacts. Ozone is highly reactive and hence reacts well with all the harmful components present in the air. Upon reaction of the Ozone with those components, it results in a reduction of the Ozone levels to near-zero so that the purified air does not contain Ozone beyond safe limits for human beings. Reduction in Ozone level is necessary to make the treated air completely safe for consumption by humans and animals alike. Therefore, our device integration ensures that the Ozone level drops to a level of near-zero before it leaves the distributer. This provides us with the two-fold benefit of not only killing the harmful constituents of the air but also ensuring that Ozone used for doing so gets neutralized before the purified and disinfected air is consumed by occupants. Hence, our device is safe for human beings in workplaces, indoor built environments where it is deployed to purify and disinfect air of Microorganisms and VOCs.
[0050] Further, in our invention, the air fed to the rooms and facilities is cleaned much before it enters the workspaces than getting cleaned post-feeding, which happens in most air purification systems currently. It also provides a significant level of reduction in harmful constituents contained in the air. Typical HVAC systems maintain air velocity of 10-12.5 m/s over a cross-section (600*400 mm). This makes the instant invention able to drive the production of Ozone through the Cold Arc Plasma generated in a spark gap.
[0051] The said air purification and disinfection device (100) of the instant invention comprises the following sub components;
Power Supply unit
[0052] Power supply unit is a step-up system which gets AC input from the normal electric supply of our households (typically, 220V, 50Hz) and provides an output in the form of an AC pulsating supply (typically, 14 kHz, 25 kV). This supply is provided across the gap in a Spark Plug with the lateral electrode being grounded and the central electrode being provided with high voltage. This results in the generation of a barrier discharge in the air in the form of a Cold Arc Plasma. When air is supplied through this cold arc, it reacts with the high density and highly energetic electrons in the region in between two electrodes and produces Ozone in significant amount during breakdown as oxygen upon degeneration gives rise to radical Oxygen molecules which further reacts with present Oxygen in the air to generate Ozone in significant amounts (typically, 7-8 ppm near the spark plug), It was also observed that with the increased velocity of air through the Cold Arc Plasma, generation of Ozone increases in its ppm level and could reach up to a level of 12-14 ppm.
[0053] Power consumption increases with an increase in air velocity but it settles with the increase beyond 2.5 m/sec of the air flow velocity as illustrated in Figure 6, which also increases the frequency and voltage of the input supply to a level that leads to the generation of the Plasma arc in the gap. It is a Cold Arc Plasma generated through the use of a Spark Plug which has a gap of 3 mm (typical).
Control System
[0054] Air purification control system as depicted by block diagram in Fig 8 and Fig 9 of the instant invention have provision where High Voltage power from the Power Supply Unit will be fed to the Spark Plugs only if the system detects that the Ozone level in the distributer vents of the duct inside the room remains well below 0.1 ppm which is as per the OSHA guideline. If the Ozone level detected by our sensor is above 0.1 ppm, the controller will ensure that the power supply is turned off. Power Supply Unit provides an output of 14kHz and 25kV for Spark generation in normal air. Oxygen molecules dissociate into atomic Oxygen in the spark region via collisions with the electrons present therein the sparking region and this atomic Oxygen combines with Oxygen molecules of fresh air circulated resulting in the generation of Ozone. Figure 7 illustrates that Ozone levels also increases with the increase in air velocity. Our Power Supply Unit is also designed to supply a multiple numbers of Spark Plugs (connected in series, parallel or combinations thereof), for effective disinfection as mentioned earlier.
Plasma Spark Cluster
[0055] The air flow through the Spark Plug takes place in a duct which is powered by an HVAC system normally installed at various built-environment facilities. The approximate air velocity of such systems is around 10-12.5m/s with a cross-section (600*400 mm). In order to generate adequate quantity of Ozone for disinfection of bulk air being supplied into workspaces, we have devised and brought out Spark Plug Cluster arrangements, wherein two or more number of Spark Plugs are arranged in a row or column or other geometric configurations thereof. These Spark Plug Clusters will be operated in full or partial modes, as decided by the capacity of HVAC system, its operating parameters and workspace / ambient conditions. We have also devised and verified various mechanical perforated enclosures to house the Spark Plug Clusters. These enclosures are made of light weight material (like Aluminium or Fiber Reinforced Plastics). The purpose of these enclosures is to create a certain amount of turbulence in the air-flow around the Spark Plug Clusters so that the ozone that is generated are quickly dispersed across the bulk of air flowing in the duct and helps to achieve effective disinfection of the air in a short period of few seconds. This also helps Ozone to get neutralized to safe levels before the air is supplied into the workplaces.
Distributer Channel of the Duct
[0056] Distributer channel is a simple distribution channel used to supply the treated air inside the room. It is an important component of any HVAC system which is already installed in place. This will be available in any air distribution system.
Ozone Sensor
[0057] This is a normal Ozone sensor with a display unit and integrated with an IoT (Internet of Thing) enabled service. The feed of this sensor is continuously going into the logs recorded online. The sensor enables to continuously monitor the level of Ozone in the room and helps to keep the level of Ozone well below the OSHA limit of 0.1 ppm. If the limit of the Ozone in the room exceeds 0.1 ppm, then a feedback signal to the power supply unit will be transmitted to shut down the power supply to the sparkplug partially or fully. This will ensure the safe and risk-free functioning of our device.
[0058] Multiple Spark Plugs were used in cluster (various geometric configurations like connected in series, parallel or combinations thereof) in an HVAC system duct so that large volume of air passing through these optimally placed Spark Plugs and hence sufficient Ozone is generated for effective disinfection and neutralization of harmful components in the supplied air.
[0059] A controller is used to detect that the Ozone level in the distributer vents of the duct inside the room; when the Ozone level detected by one of the sensors is above 0.1 ppm, then the controller senses it and ensures that the power supply is turned off.
[0060] Figure 1 is a perspective view of the air purification device (100); the assembly of said device (100) is made in a manner that it is easy to install and can be placed inside the existing air ducts (200) with minimal efforts at any facility. The positioning of this device (100) can be done at various stages of the Air Handling Unit (AHU) based on one or more factors such as, air quality available before hand, capacity of the air handling unit, types of pollutants/components released at the user end floor or the frequency of maintenance intervals and accessibility of the existing components. Placing the device (100) before the AHU can gradually increase the life of HEPA filters, which reduces the requirement of high-pressure drop mediums and also reduce frequency of human intervention for cleaning and maintenance. Bacterial accumulation and greasing of Organic & Inorganic compounds inside the air ducts, where accessibility is almost impossible, can also be prevented due to the oxidation capabilities of the Ozone (104) released by spark-plugs (102) which are connected in series with power circuit unit. This entire assembly together is termed as Ozone generating unit (105) enclosed in a hexagonal outer shell (101) made up of a metal which also used for wire routing. Device (100) can be installed by drilling a hole for inserting the outer shell (101) which is holding the Spark Plugs (102) and can be mounted either by riveting/screw mounting (116) on the duct (200).
[0061] Figure 2 shows assembly of the Spark Plugs (102) which is designed in such a way that they are easy-to-remove and change without any interactions with other components of the Ozone generating unit (105). In case of any failure of Spark Plugs (102), maintenance/cleaning to be done, these Spark Plugs (102) can be unscrewed easily out of their position. The advantage of this method is that it eliminates the requirement of any authorized personnel to handle it. In case of any malfunction, any in-house maintenance person can easily rectify the problem with less effort, without requiring the entire Air Handling Unit (AHU) to be switched off.
[0062] Figure 3 depicts the process starting from the air which is drawn from the environment through HVAC unit and enters the Ozone generating unit (105) where Ozone (104) is generated. The generated Ozone at the proximity of the six Spark Plugs (102) will react with the input air. Ozone (104) in turn will react with the viruses, where it deactivates/destroys the properties/capacity of the viruses, leaving its effectiveness diminished. Other components in the air will also react with Ozone (104) which in turn reduces the concentration of the Ozone (104) as it travels through the duct (200), where the concentration of Ozone (104) is negligible or in traces. The Ozone sensor (106) will continuously send feedback to the controller (107) for monitoring or controlling air purification control system (108). Air purification control system (108) is divided into three zones; a) Plasma spark zone which will have good amount of Ozone concentration towards its beginning point and as the air passes through it, the concentration will gradually increase. b) Reaction zone which is usually a long path, since Ozone (104) takes a long time to react with the components/compounds present in the air. The reaction efficiency will depend upon the mixing turbulence generated inside the duct (200) by the assembly obstruction which does not affect the air flow delivery rate much. The long path also ensures proper consumption of Ozone particles. c) Sensor zone which will have an Ozone sensor (106) installed at the distant (far) end of the device (100) to measure the concentration of Ozone. Any deviation from the set limit will send a feedback signal to the controller (107) which will turn off the air purification device either partially or fully (100)
[0063] Figure 4 shows the installation of air purification device (100) in a duct (200) to which an IoT- based communication device can also be integrated which will enable real time access to generated data logs of the input/available air quality, power consumption, concentration levels inside the duct (200) and related crucial parameters. This data log will be fed to an application/website program which will perform basic analysis and evaluations on the atmosphere at which the air purification device operates. These analyses will help further improving the peripheral operations involved to improve the air quality based on the requirement of the delivery floor. Further, the integration of an air purification device (100) can also help perform external control in case of specific requirements at special situations like fire hazard control with humidifiers. The introduction of other safety devices and small air processing units can also be supported without any significant investments for maintenance and change-overs.
[0064] Figure 5a is an illustration of different zones which together makes the said air purification control system (108) comprising Plasma spark generation zone, even at dry condition (no air flow) will generate a very good amount of Ozone (104) in a range of about 4-5ppm.With even minimum air flow velocity the spark propagates leading to the increase in Ozone generation. A minimum air flow velocity of 1m/s was given as the input, and Ozone (104) measured was found to hike to about 9ppm. A generic household will have an air flow velocity of 0.8m/s to 1m/s, and this velocity goes up to 20-22m/s in industrial duct standards. The Ozone concentration stabilizes when the velocity increases beyond 3m/s.
Examples
Example-1
In experimental conditions, the air flow velocity directly from the HVAC was about 12m/s, the Spark Plug (102) assembly was located about 4-5m from the HVAC Unit. The air distribution ports to the floor from this generation point was about 2-3m. There was no trace of Ozone inside the closed room even after the unit ran for over 3 hours. In figure 5a, the air inlet velocity from the HVAC unit was about 12m/s which enters the Spark Zone. The velocity reduction at the assembly point will be very negligible. The pressure of air supply from HVAC will ensure the velocity loss caused by obstruction to recover and reach the desired velocity at delivery ports in the duct. The red particles indicate unprocessed air from the HVAC; after air reaches the spark zone, the velocity reduction causes the concentration of Ozone (104) to distribute along the cross-section and as the air travels further, the turbulence generated due to the geometry of outer shell (101) ensures proper mixing of Ozone (104) with the air components. The high Ozone (104) concentration at the generation point (indicated in dark blue) mixes with the air components. The concentration dilution over the travel length ensures quenching of Ozone (104) as it reaches the sensor zone of the air purification system (108) having Ozone sensor (106) placed at the distal end of the device (100). The Sensor Zone of the air purification system (108) has feedback to the switching circuit, based on the measurement made, depending on the delivery environment and the remaining travel distance of the air particles. By this stage, the air regains its laminar motion of flow and also becomes free from viral load and Odour. This air passes to the distribution ports for further processing if required and then for delivery to the workplace (room).
Example-2
A Power Supply unit powered by standard AC input voltage was connected with a power consumption meter. The quantity of Spark Plugs connected across this unit was varied to study the effects of power consumption with an increase in quantity. The observation was made without any air flow in this case. The table below shows the amount of power consumed with an increase in a number of Spark Plugs.
Spark Plugs connected in Series, with Power Supply Unit
No. of Spark Plugs Voltage (V) Frequency (Hz) Current(mA) Power Consumed (W)
1 247.5 50 82 18.6
2 117 26.8
3 146 33.5
4 247.2 39.1
Also, the gap/distance between the electrodes will have a significant effect on the Ozone generation.
Example-3
A Spark Plug arrangement was made inside a container, in a way to supply air directly to the spark zone. The Inlet Air flow velocity was measured with a Hot Wire Anemometer. The effect of Air Flow Velocity on the Ozone concentration and Power consumption was observed. Both power consumption and Ozone concentration increased with an increase in air flow velocity and stabilized at the velocity range of 3 to 3.5m/s. Further, any increase in the velocity did not affect both parameters significantly.
Air Supply at Spark Zone (fig 6 & 7)
Velocity (m/s) Power Consumption (W) Ozone Concentration (ppm)
0 – 0.5 16.4 9.0
0.5 – 1 19 9.3
1 – 1.5 19.8 9.8
1.5 – 2 20 10.4
2 – 2.5 20.6 11.2
2.5 – 3 20.9 11.8
3 – 3.5 21.2 12.2
3.5 – 4 21.7 12.5
4 – 4.5 21.7 12.7
4.5 – 5 21.8 12.7

LIST OF REFERENCE SIGNS IN THE FIGURES
Air purification Device 100
Outer shell 101
Spark Plug 102
Arc 103
Ozone 104
Ozone generating unit 105
Ozone sensor 106
Controller 107
Air purification control system 108
Power circuit board 110
Spark Plug Assembly 111
Plasma PCB 112
Switching circuit 113
Ozone control board 114
Wiring 115
Mounting means 116