WO2022238993A1

WO2022238993A1 - An indoor ozone based air purification system and method

Info

Publication number: WO2022238993A1
Application number: PCT/IL2022/050476
Authority: WO
Inventors: Itzhak KRIEZE
Original assignee: Virusafe Technologies Ltd
Priority date: 2021-05-12
Filing date: 2022-05-08
Publication date: 2022-11-17
Also published as: IL283138A

Abstract

The present invention relates to an indoor ozone-based sterilization air purification system for detecting germs and disinfecting a room safely in the presence of humans, comprising: (a) at least one germicidal lamp for producing ozone; (b) at least one ballast connected in series with said germicidal lamp in order to regulate the amount of current to said germicidal lamp; (c) at least one ozone concentration detection module; and (d) a controller, which calculates the subjective predetermined ozone concentration limit based on readings from said ozone concentration detection module, and wherein said controller turns on said germicidal lamp, using said ballast, for generating the ozone when the average of said readings is below said subjective predetermined ozone concentration limit, and for turning off said germicidal lamp, using said ballast, for ceasing the generating of the ozone when the average of said readings is above said subjective predetermined ozone concentration.

Description

- 1 -

AN INDOOR OZONE BASED AIR PURIFICATION SYSTEM

AND METHOD

Technical Field

The present invention relates to air cleaning systems for purifying air. More particularly, to an indoor ozone-based air purification system and method for detecting and inactivating germs.

Background

Ozone is a gas formed by molecules made up of 3 oxygen atoms (O3) and has the characteristic of being a powerful oxidizing agent. Thanks to this property it has proven to be highly effective in killing bacteria, fungi and inactivating viruses. Ozone can, therefore, be used for the treatment of potentially contaminated surfaces, water, and ambient air thanks to its powerful germicidal effect on a wide spectrum of microorganisms.

The effectiveness of ozone in treating microorganisms, especially bacteria and viruses, is related to various factors, i.e., ozone concentration, the temperature of the environment, humidity of the environment and exposure time.

Capsid surface proteins, as well as membrane receptors present on enveloped viruses, are the first targets of ozone because it reacts directly with amino acids and functional groups of proteins. This leads to various consequences both on the structure of the virus, which is compromised, and on its infectious capacity because the specific viral receptors used by the virus to bind to host cells and invade them are altered. Furthermore, ozone 2 damages the membranes of the enveloped viruses through peroxidation of phospholipids and generating numerous Reactive Oxygen Species (ROS) capable of damaging also other viral macromolecules. In addition, ozone can inactivate viruses by causing damage to their genetic material, both DNA and RNA. The main mechanisms by which ozone acts on viruses, therefore, are due to the direct oxidation of various molecules and, indirectly, with the generation of ROS. Coronaviruses are classified as “enveloped viruses”, which are typically more susceptible to “Physico-chemical challenges”. In other words, ozone can neutralize coronaviruses. Ozone destroys this type of virus by breaking through the outer shell into the core, resulting in damage to the viral RNA. Ozone can also damage the outer shell of the virus in a process called oxidation.

While ozone is an excellent material for oxidizing germs, it is itself a highly toxic substance. The Occupational Safety and Health Administration (OSHA) requires that workers not be exposed to an average concentration level of more than 100 ppb (parts per billion) for more than 8 hours a day. For human beings, breathing ozone beyond the approved concentration can be harmful, and may cause symptoms such as coughing, shortness of breath, and aggravation of lung diseases like asthma. For that reason, many countries, today, have set a limit of 120-140 ppb (parts per billion) for ozone concentration levels.

Thus, while the use of ozone, as a material for oxidizing germs, is known to be effective, the hazardous nature of the ozone, for humans, has prevented it from widespread use. Some of the prior art publications have disclosed the use of ozone concentration detection modules in order to control the ozone concentration in the air. Nevertheless, even very expensive ozone concentration detection modules have been found to be inaccurate for - 3 - measuring ozone at these very low levels. For these reasons, prior art purification systems are typically used for disinfecting an indoor room only when the room is evacuated from humans. Typically, once a space is vacated of humans, one of the prior art systems can be bought into the room and turned on while the room is closed. At this stage, the system can boost the ozone concentration in the room to much more than 100 ppb, effectively deactivating 99.99% of the viruses. After the disinfection, the system is turned off and the room is typically kept closed for at least a half an hour, in order to allow the ozone in the room to dissipate before anyone comes back into the room. Nevertheless, these prior art systems are not allowed to operate in the presence of humans for the reasons described above.

WO2016175473A1 discloses an Internet of Things-based (IOT) ozone sterilization air purification system for purifying air by increasing the amount of air to be purified by an air purifier. The disclosed object-based Internet air purification system includes a plurality of air purifiers arranged to be spaced apart from each other, where the disclosed object-based Internet ozone sterilizing air purification system comprises: An ozone generating unit for generating ozone by generating ozone in the air sucked into the air intake port; and an ozone generator installed inside the purifier body for discharging ozone generated in the ozone generator to the air outlet; an ozone discharge sensor for detecting the presence or absence of ozone in the air discharged to the air outlet; and an ozone sensor for detecting the presence or absence of ozone in the air discharged from the air outlet module. When an IOT module receives the ozone detection information, it can improve the air purifying capability by enabling a plurality of air purifiers to be linked to each other through the Internet of Things. Nevertheless, the disclosed system has limited use. - 4 -

CN1 11692665 discloses an intelligent air purifier which comprises a control module, and an air purification module, an ozone concentration detection module and an ozone reduction module connected to the control module, wherein the ozone concentration detection module is arranged at a purification air outlet of the air purification module and is located between the air purification module and the ozone reduction module. As disclosed, the air purification module is used for purifying air. The ozone concentration detection module is used for detecting ozone concentration of ozone generated by operation of the air purification module, where the ozone reduction module is used for reducing ozone generated by operation of the air purification module when the detected ozone concentration is greater than an ozone concentration threshold value. The described control module is used for controlling opening and closing of the air purification module, the ozone concentration detection module and the ozone reduction module and is further used for sending the starting command to the ozone reduction module when the detected ozone concentration is greater than an ozone concentration threshold value. Nevertheless, the described intelligent air purifier can be inaccurate and therefore may be dangerous.

It would therefore be desired to propose a system void of these deficiencies.

Summary

It is an object of the present invention to provide an indoor ozone-based sterilization air purification system capable of detecting and disinfecting a room from a wide spectrum of microorganisms. - 5

It is another object of the present invention to provide an indoor ozone- based sterilization air purification system which can disinfect a room safely in the presence of humans.

It is still another object of the present invention to provide an indoor ozone-based sterilization air purification system which can detect a sudden change in the quantity of germs in the room and inactivate many of them.

It is still another object of the present invention to provide an indoor ozone-based sterilization air purification system which can be controlled and monitored both remotely and manually.

It is still another object of the present invention to provide an indoor ozone-based sterilization air purification system for detecting if a sick person has entered the room.

Other objects and advantages of the invention will become apparent as the description proceeds.

The present invention relates to an indoor ozone-based sterilization air purification system for detecting germs and disinfecting a room safely in the presence of humans, comprising: (a) at least one germicidal lamp for producing ozone; (b) at least one ballast connected in series with said germicidal lamp in order to regulate the amount of current to said germicidal lamp; (c) at least one ozone concentration detection module; and (d) a controller connected to said at least one ballast and connected to said at least one ozone concentration detection module, wherein said controller calculates the subjective predetermined ozone concentration limit based on readings from said ozone concentration detection module and wherein said controller 6 reads the concentration of the ozone, from said at least one ozone concentration detection module, continuously for a predefined time for calculating the average of the readings in said time, and for turning on said germicidal lamp, using said ballast, for generating the ozone when the average of said readings is below said subjective predetermined ozone concentration limit, and for turning off said germicidal lamp, using said ballast, for ceasing the generating of the ozone when the average of said readings is above said subjective predetermined ozone concentration.

Preferably, the predetermined time is 2 minutes.

Preferably, the system further comprises communication means for communicating with a remote base or receive commands remotely.

Preferably, the system further comprises a fan for inhaling the air from the room and exhaling the purified air back into the room.

Preferably, the system further comprises a cover for covering and protecting the inner parts of said system and for controlling the air flow of the system.

Preferably, the system further comprises an Ultraviolet Light Lamp.

Preferably, the system further comprises at least one air-quality detection sensor for detecting the quality of the air as well.

Preferably, the system further comprises a HEPA or ULPA filter for filtering the air. - 7 -

Preferably, the subjective predetermined ozone concentration limit is calculated to equal to about the objective concentration of 50 ppb of the ozone in the air.

The present invention also relates to an indoor ozone -based sterilization air purification method for detecting germs and disinfecting a room safely, in the presence of humans, comprising: (a) providing at least one germicidal lamp for producing ozone; (b) providing at least one ballast connected in series with said germicidal lamp for regulating the amount of current to the said germicidal lamp; (c) providing at least one ozone concentration detection module; (d) providing a controller connected to said at least one ballast for controlling said germicidal lamp and connected to said at least one ozone concentration detection module; (e) calculating the subjective predetermined ozone concentration limit based on readings from said ozone concentration detection module; (f) reading the concentration of the ozone, from said at least one ozone concentration detection module, continuously for a predefined time for calculating the average of the readings in said time; and (g) turning on said germicidal lamp, using said ballast, for generating the ozone when the average of said readings is below said subjective predetermined ozone concentration limit, and for turning off said germicidal lamp, using said ballast, for ceasing the generating of the ozone when the average of said readings is above said subjective predetermined ozone concentration.

Brief Description of the Drawings

The accompanying drawings, and specific references to their details, are herein used, by way of example only, to illustratively describe some of the embodiments of the invention. 8

In the drawings:

Fig. 1 is a diagram of the indoor ozone-based sterilization air purification system, and some of its inner part, according to an embodiment of the invention.

Detailed Description

Prior art purification systems, which implement indoor ozone-based sterilization systems during the presence of humans, typically employ an ozone generating unit and an ozone concentration detection module in order to control the ozone concentration in the air. Nevertheless, even very expensive ozone concentration detection modules have been found to be inaccurate for measuring ozone, especially in very low concentrations, as required in many countries worldwide. Furthermore, the use of multiple ozone concentration detection modules has been found to lead to different results with a considerable variation between the measurements. As of today, according to The Occupational Safety and Health Administration (OSHA), there is no known system that can safely detect and monitor the accurate required low concentration levels of ozone, e.g. 50 - 100 ppb range, in the air in a room.

The inventor has surprisingly found that when there is a considerable quantity of microorganisms in a room the generated ozone, from a typical air purifier, interacts with the microorganisms and therefore the ozone concentration cannot be effectively detected in the room, at this low level of 50 - 100 ppb range. Nevertheless, once the generated ozone has inactivated most of the microorganisms (in some cases more than 98% of the - 9 - microorganisms), the concentration level of the ozone begins to increase rapidly. Furthermore, even if the concentration of the ozone, in a room, is high and a human, which disperses germs and other microorganisms, enters the room - the concentration of the ozone drops, as the ozone in the room interacts with the microorganisms. Thus, the inventor has found that the concentration of the ozone, in a room, is highly affected by the quantity of microorganisms in the room.

When starting to generate ozone indoors, if there are enough microorganisms in the room, the concentration of ozone in the room may be very low and even undetectable, to a typical ozone concentration detection module, whereas, when the room is becoming disinfected, the measured ozone rises rapidly even when there is no change in the rate of the ozone generation. Thus, when taking into account the fact that today there are no accurate ozone detectors, in the low levels of 50 - 100 ppb range, the inventor has found that it is more effective to measure the change, e.g. derivative, of the ozone concentration in the room, than to measure the ozone concentration itself in the room, as in the prior arts. Thus, in some cases, a cheaper ozone concentration detection module may be used, than the ones disclosed in the prior arts.

Fig. 1 is a diagram of the indoor ozone-based sterilization air purification system, and some of its inner part, according to an embodiment of the invention. The indoor ozone-based sterilization air purification system comprises at least one germicidal lamp 20 for producing ozone, such as the ZW24D15Y-U170 produced by Foshan Yuqi Aviation Optics Technology co., or any other ultraviolet (UVC) light that produces ozone or any other ozone producing device. In one embodiment the germicidal lamp 20 may have a consumption of between 3-60 watt. In another embodiment the germicidal 10 lamp 20 may have a consumption of between 7-24 watt. In one embodiment the germicidal lamp 20 may be 1-60 grams Ozone Ceramic Plates for producing ozone. In one embodiment, at least one ballast 30, such as PW12- 425-18 produced by Foshan Yuqi Aviation Optics Technology co., may be added to the system in series with the lamp 20 in order to regulate the amount of current to the lamp 20. In one embodiment the ballast 30 may be a Light Electronic Ballast, with an entry input of 220vac, 24vdc or 12vdc, or any other input. The system also comprises at least one ozone concentration detection module 60, such as a Winsen Model # ZE 14-03. At least one fan 40 may be added to the system, such as a fan 80/120 EC series or 80/120 DC series produced by Zhengzhou Airmoving Technology Co. Ltd., for inhaling the air into the system for purifying the air and exhaling the purified air back into the room. The system also comprises a controller 50, such as an ESP32-S controller, for controlling at least the lamps, ballasts, and detection modules. In one embodiment the controller 50 may have communication capabilities as well such as WiFi, Bluetooth and/or cellular communications, or may be attached to other communication means. In one embodiment the system may also have a cover 70, for covering and protecting the inner parts of the system and for controlling the air flow of the system. In one embodiment, the cover may be easily opened and closed in order to allow the easy replacements of some of the inner part such as the germicidal lamp and the ballast.

According to one embodiment, the proposed indoor ozone-based sterilization air purification system may be programmed with a subjective predetermined limit for the concentration of ozone, that is, each system may have its own predetermined limit for the concentration of ozone. In one embodiment, the subjective predetermined limit of each system is calculated to equal to about the objective concentration of 50 ppb of the ozone in the air. In another embodiment, the subjective predetermined limit of each system is 11 calculated to equal to an objective concentration of between 50-100 ppb of the ozone in the air. The calculation of the subjective predetermined limit for the concentration of ozone, for each system, will be described later. The controller, of the system, may read the concentration of the ozone, from the detection module, continuously for a predefined time, e.g. for 2 minutes, and calculate the average of the readings. If the average of the readings is below the predetermined limit, the controller can turn on the germicidal lamp for generating the ozone. If, however, the average of the readings is above the predetermined limit the controller can turn off the germicidal lamp for ceasing the generating of the ozone. The controller may then stop reading the value of the concentration of the ozone, from the detection module for a predefined off time, e.g. for 10 minutes. In one embodiment the controller of the system, continues reading the concentration of the ozone, from the detection module, and the off time may continue until the average, e.g. of the last 2 minutes, of the readings is less than half of the predetermined limit of the system. In one embodiment, the off time may continue until the latest of the two off times described before. After the off time, the controller starts the same cycle again. In any case the controller may stop the generating of the ozone for 20 minutes every hour, or any other predefined recess.

In one embodiment the subjective predetermined limit of the system may be calculated each day by the controller in relations to it's “start” value measurement. In this embodiment the controller is programmed to stop the generation of ozone for a break, e.g. for 6 hours, preferably when the room is evacuated from humans, for example at night. After which the controller of the system calculates the average of the readings, from the detection module, from the last period of the time, e.g. 30 minutes, and sets the calculated average as the “start” value of the detection module for the day. After detecting, measuring, and calculating the “start” for the day, the controller 12 can calculate the subjective predetermined limit for the day. In one embodiment, if the calculated “start” value is 25 or lower the limit can be calculated as the set “start” value times 4.5. For example, if the “start” is found to be 24 the limit is set to 108. In one embodiment, if the calculated “start” is between 25-30 the limit can be calculated as the “start” times 4. In one embodiment, if the calculated “start” is between 30-45 the limit can be calculated as the start times 3. In one embodiment, if the calculated “start” is above 45 the limit can be calculated as the start times 2.5. In other embodiments, there may be other calculations of the limit in relations to the start point. In one embodiment, the calculations of the subjective predetermined limit, in relations to the start point, are for determining the limit which equals to about the objective concentration of 50 pbb of the ozone in the air.

In another embodiment, the subjective predetermined limit of the system may be defined by placing the system in a controlled environment which is known to have a defined concentration of ozone, e.g. 50 pbb. Then, the controller calculates the average readings of the system for a certain amount of time, e.g. for 30 minutes, in the controlled environment. The average readings are then processed to define the predefined limit. For example, if the average readings, from the detection module of the system, for 30 minutes in a controlled environment of 50 pbb, are calculated to be 75, then the subjective predetermined limit of that system is calculated to be 75.

In one embodiment, the proposed indoor ozone-based sterilization air purification system may be controlled, from a remote base, via communication means such as Wi-Fi. Since the ozone concentration of more than 50 ppb has a certain smell, the user in the room of the system may request to reduce the subjective ozone concentration limit. The user may call - 13 - the base or communicate in any other way with the base. Thus, the remote base may reduce the subjective predetermined ozone concentration limit even lower via communication means based on the user’s smelling sense. In one embodiment the user may communicate directly with the system, using a button or other wire/wireless communication means, for recalculating the subjective predetermined ozone concentration limit. In both cases the user defined ozone concentration limit may become the subjective predetermined ozone concentration limit of the system.

In one embodiment if the calculated subjective predetermined ozone concentration limit is above the limit specified by the user, the user limit will prevail as the limit for the system, however, if the calculated limit is below the limit specified by the user, the calculated daily limit will prevail as the limit for the system.

In one embodiment the predetermined limit of the system may be calculated specifically for the room the system is installed in. Since the power of the system is known, once the room size is entered into the system, the predetermined limit for the system can be calculated. For example, if a, 1 watt germicidal lamp may produce a constant Ozone concentration of 50 ppb for a 10 m³ space, then if a system has a 2 watt germicidal lamp, and the entered room size is 10 m³ the lamp needs to be on for 30 minutes each hour in order to achieve a constant Ozone concentration of 50 ppb. In one embodiment the equation to calculate the amount of time it is required to operate the Ozone Lamp to achieve concentration of 50 ppb, when there are no microorganisms present in the room, may be calculated as follows: - 14 -

60*R / 10*P = T

Where:

R- the room space in cubic meters

P - lamp power in Watts (or mg/h where 1 Watt=4 mg/h)

T — the minutes per hour the lamp needs to be turned on

In one embodiment the result from the equation is first multiplied by 4 and is calculated as the time limit for generating Ozone in in a single interval. This time limit may be used as an extra safety limit to the system. For example, if the size of the room is 100m³, and the power of the Ozone lamp, of the system, is 20w, and the room space is 100m³ then: 60*100/(10*20)= 30 minutes, then the time limit of the operation of the system is calculated to 30m*4= 120min maximum.

The different options discussed above, are for detecting and disinfecting a room while keeping the concentration of the ozone in the low levels of 50 - 100 ppb range, for operating in a room in the presence of humans.

In one embodiment, the data from many systems may be accumulated and processed for tuning the equation and the systems even further.

In one embodiment, the data, from many systems that have been installed, may be accumulated and processed for tuning the subjective predetermined limit of each of the systems for any one of the options, discussed above, using big data and/or any form of machine learning and/or simple calculations. - 15 -

In one embodiment, the difference between the calculated predicted time required for the generated Ozone to reach the subjective predetermined limit and between the actual time that took the system to reach the subjective predetermined limit, allows the calculation of the amount of microorganism in the space. For example, if the system is known to require 1 hour to reach its subjective predetermined limit, under typical conditions, and it took the system more than twice the time to reach its subjective predetermined limit, then the system can calculate that the amount of microorganisms in the space was much more than the typical conditions.

In one embodiment, the proposed indoor ozone-based sterilization air purification system may also be used for detecting if a sick person, which disperses many germs and other microorganisms, entered the room. That is, if the detection module has shown a sudden drop in the ozone concentration in the room the system can alert that a sick man has entered the room. For example, if the detection module has shown a drop of at least 50% in the ozone concentration in the room in less than a 5-minute time frame, the system may alert that a sick person has entered the room.

In one embodiment, the proposed system may be a stand-alone system and may be installed in a room. In another embodiment, the proposed system may be installed in an air conditioning unit.

In one embodiment, the proposed system may have a wired/wireless communication unit, where the unit can communicate with a remote base or receive commands remotely. The communication means may be any of the known communication means such as Wi-Fi, BT, Cellular. - 16 -

In one embodiment, a Germicidal Disinfection Uvc Ultraviolet Light Lamp, such as ZW24D15Y-U171 may be added as well to the system. In one embodiment the Ultraviolet Light Lamp may be turned continuously on for additional purification even when the ozone generation is turned off.

In one embodiment, the system may have air-quality detection sensors such as the WINSEN ZP07-503 for detecting the quality of the air as well for advising the customer of the quality of the air in the room.

In one embodiment, the system may have a filter for filtering the air such as a HEPA filter model # JHC-118 manufactured by Huizhou Jinhaocheng Co.

While the above description discloses many embodiments and specifications of the invention, these were described by way of illustration and should not be construed as limitations on the scope of the invention. The described invention may be carried into practice with many modifications which are within the scope of the appended claims.

Claims

- 17 -Claims

1. An indoor ozone -based sterilization air purification system for detecting germs and disinfecting a room safely in the presence of humans, comprising: a. at least one germicidal lamp for producing ozone; b. at least one ballast connected in series with said germicidal lamp in order to regulate the amount of current to said germicidal lamp; c. at least one ozone concentration detection module; and d. a controller connected to said at least one ballast and connected to said at least one ozone concentration detection module, wherein said controller calculates the subjective predetermined ozone concentration limit based on readings from said ozone concentration detection module and wherein said controller reads the concentration of the ozone, from said at least one ozone concentration detection module, continuously for a predefined time for calculating the average of the readings in said time, and for turning on said germicidal lamp, using said ballast, for generating the ozone when the average of said readings is below said subjective predetermined ozone concentration limit, and for turning off said germicidal lamp, using said ballast, for ceasing the generating of the ozone when the average of said readings is above said subjective predetermined ozone concentration.

2. A system according to claim 1, where the predetermined time is 2 minutes.

3. A system according to claim 1 further comprising communication means for communicating with a remote base or receive commands remotely. - 18 - A system according to claim 1 further comprising fan for inhaling the air from the room and exhaling the purified air back into the room. A system according to claim 4 further comprising a cover for covering and protecting the inner parts of said system and for controlling the air flow of the system. A system according to claim 1 further comprising an Ultraviolet Light Lamp. A system according to claim 1 further comprising at least one air- quality detection sensor for detecting the quality of the air as well. A system according to claim 1 further comprising a HEPA or ULPA filter for filtering the air. A system according to claim 1, where the subjective predetermined ozone concentration limit is calculated to equal to about the objective concentration of 50 ppb of the ozone in the air. An indoor ozone-based sterilization air purification method for detecting germs and disinfecting a room safely, in the presence of humans, comprising: a. providing at least one germicidal lamp for producing ozone; b. providing at least one ballast connected in series with said germicidal lamp for regulating the amount of current to the said germicidal lamp; c. providing at least one ozone concentration detection module; and d. providing a controller connected to said at least one ballast for controlling said germicidal lamp and connected to said at least one ozone concentration detection module; e. calculating the subjective predetermined ozone concentration limit based on readings from said ozone concentration detection module; - 19 - f. reading the concentration of the ozone, from said at least one ozone concentration detection module, continuously for a predefined time for calculating the average of the readings in said time; and g. turning on said germicidal lamp, using said ballast, for generating the ozone when the average of said readings is below said subjective predetermined ozone concentration limit, and for turning off said germicidal lamp, using said ballast, for ceasing the generating of the ozone when the average of said readings is above said subjective predetermined ozone concentration. A method according to claim 10, where the predetermined time is 2 minutes. A method according to claim 10 further providing communication means for communicating with a remote base or receive commands remotely. A method according to claim 10 further providing a fan for inhaling the air from the room and exhaling the purified air back into the room. A method according to claim 13 further providing a cover for covering and protecting the inner parts of said system and for controlling the air flow of the system. A method according to claim 10 further providing an Ultraviolet Light Lamp. A method according to claim 10 further providing at least one air- quality detection sensor for detecting the quality of the air as well. A method according to claim 10 further providing a HEPA or ULPA filter for filtering the air. A method according to claim 10, where the subjective predetermined ozone concentration limit is calculated to equal to about the objective concentration of 50 ppb of the ozone in the air.