CA2776850C

CA2776850C - A method and system for disinfecting a greenhouse and greenhouse related enclosures

Info

Publication number: CA2776850C
Application number: CA2776850A
Authority: CA
Inventors: Menno KOEHOORN
Original assignee: TECH MIST SPRAY SOLUTIONS Inc
Current assignee: TECH MIST SPRAY SOLUTIONS Inc
Priority date: 2012-05-11
Filing date: 2012-05-11
Publication date: 2019-03-05
Anticipated expiration: 2032-05-11
Also published as: WO2013166597A1; CA2776850A1

Abstract

A method and system of disinfecting a greenhouse enclosure or greenhouse related enclosure is provided. The method may include providing an ozone generator, inserting an ozone delivery conduit from the ozone generator into the enclosure, restricting access to the enclosure to prevent public access, and substantially sealing the enclosure such that air inside the enclosure is substantially prevented from exiting. The method may also include creating an ozone enriched atmosphere within the enclosure by generating gaseous ozone into the enclosure to an effective ozone concentration and monitoring the ozone concentration within the enclosure. Once an effective period of time expires, the ozone may be removed from within the enclosure to a level safe for public access. The system may include an ozone generator having an ozone delivery conduit for delivery of gaseous ozone from the generator into the enclosure and an ozone concentration measuring device for monitoring and measuring ozone concentration within the enclosure. The ozone concentration measuring device may be operable to communicate with a computer processing unit. The computer processing unit may be operable to communicate with the generator to control the production of ozone.

Description

TITLE OF THE INVENTION
A METHOD AND SYSTEM FOR DISINFECTING A GREENHOUSE AND
GREENHOUSE RELATED ENCLOSURES /
FIELD OF THE INVENTION
The invention relates to the field of disinfecting and in particular relates to a method and system for disinfecting a greenhouse and greenhouse related enclosures.
BACKGROUND OF THE INVENTION
Typical greenhouses and greenhouse related enclosures are difficult and time consuming to sanitize using conventional methods such as antiseptic cleaners and the like. Conventional cleaners are comprised typically of chemicals that carry carcinogenic and mutagenic residuals that could harm workers and damage biological controls in a greenhouse. Pathogens such as germs and viruses can remain in the enclosure and infect plants and people without proper disinfection.
The use of ozone is well known as a disinfectant or sterilizing agent. Ozone is a powerful oxidizer which effectively kills microorganisms. Applications in water and waste treatments are well documented. In addition to the cost effectiveness and strong oxidizing power of ozone, the penetrating property of ozone makes it an ideal aerial disinfectant as well as a surface disinfectant. Ozone is a useful disinfectant of rooms or enclosed spaces and their surfaces, because as a gas it readily penetrates into corners and crevices of an enclosed space.
Ozone (03) is an unstable gas comprising three atoms of oxygen. It is unstable because ozone gas will readily degrade back to its stable state, diatomic oxygen

(02), the form of oxygen humans breathe to live, with the formation of free oxygen atoms or free radicals. The free oxygen atoms are highly reactive and will oxidize almost everything, including viruses, fungi, moulds, bacteria, organic and inorganic compounds. Ozone's high level of oxidation properties means that in addition to being a disinfectant, it is capable of eliminating odors caused by animals, smoke, and fuel. Following sanitization with ozone, the sanitized space will be left with a clean, fresh smell. Ozone is considered an environmentally friendly disinfectant, because it is a potent disinfectant at low concentrations, it does not produce any harmful chemical compounds with harmful residues and all residual ozone used in disinfection is converted back to oxygen with carbon dioxide and other minor concentration of gases within a relatively short period of time.
Ozone generators are presently available which are marketed to be used continuously in an enclosed space and in the presence of humans and animals to remove odors and freshen the air. However, the level of ozone generated by these ozone generators is low, since the ozone concentrations must be maintained at levels which will not adversely affect occupants. It is generally accepted that the maximum ozone concentration in an atmosphere occupied by humans for any significant length of time is 0.1 parts per million (ppm), and preferably ozone concentration is below 0.05 ppm.
Accordingly, a need exists for a chemical free method and system to disinfect a greenhouse or greenhouse related enclosure using high concentrations of ozone.

Other objects of the invention will be apparent from the description that follows.
SUMMARY OF THE INVENTION
According to the present invention there is provided a method of disinfecting a greenhouse enclosure or greenhouse related enclosure. The method may include providing an ozone generator, inserting an ozone delivery conduit from the ozone generator into the enclosure, restricting access to the enclosure to prevent public access, and substantially sealing the enclosure such that air inside the enclosure is substantially prevented from exiting. The method may also include creating an ozone enriched atmosphere within the enclosure by generating gaseous ozone into the enclosure to an effective ozone concentration, for example, between 0.5 ppm to 200 ppm, and monitoring the ozone concentration within the enclosure. Once an effective period of time, for example, between 0.25 and 32 hours, expires, the ozone may be removed from within the enclosure to a level safe for public access.
According to another aspect of the present invention, there is provided a method of disinfecting a greenhouse enclosure or greenhouse related enclosure, where the enclosure includes a CO2 injection system operable to circulate CO2 throughout the enclosure. The method may include providing an ozone generator, inserting an ozone delivery conduit from the ozone generator into the CO2 injection system, restricting access to the enclosure to prevent public access, and substantially sealing the enclosure such that air inside the enclosure is substantially prevented from exiting. The method may also include creating an ozone enriched atmosphere within the enclosure by generating gaseous ozone into the enclosure to an effective ozone concentration, for example, between 0.5 ppm to 200 ppm, and monitoring the ozone concentration within the enclosure.
Once an effective period of time, for example, between 0.25 and 32 hours, expires, the ozone may be removed from within the enclosure to a level safe for public access.
The methods may also include circulating the ozone enriched atmosphere inside the enclosure with an air movement device.
The methods may also include signally to the public when said ozone concentration within the enclosure is reduced to a maximum level of 0.1 ppm.
The signally may include a strobe light.

3 Additionally, the methods may include increasing the relative humidity within the enclosure during disinfection, increasing the temperature within the enclosure during disinfection, and/or increasing the atmospheric pressure within the enclosure during disinfection.
Monitoring the ozone concentration within the enclosure may include providing an ozone concentration measuring device operable to communicate with a computer processing unit. The computer processing unit may be operable to communicate with the generator to control the output of ozone. The computer processing unit may also be operable to communicate with a remote mobile device, or be itself, a remote mobile device.
According to yet another aspect of the present invention, there is provided a system for disinfecting a greenhouse enclosure or greenhouse related enclosure.
The system may include an ozone generator having an ozone delivery conduit for delivery of gaseous ozone from the generator into the enclosure and an ozone concentration measuring device for monitoring and measuring ozone concentration within the enclosure. The ozone concentration measuring device may be operable to communicate with a computer processing unit. The computer processing unit may be operable to communicate with the generator to control the production of ozone. The computer processing unit may be operable to communicate with a remote mobile device, or be itself, a remote mobile device.
Additionally, the system may include an air movement device to circulate the ozone within the enclosure and a signaling device, such as a strobe light, for notifying the public when said ozone concentration is reduced to a maximum level of 0.1 ppm. The system may include a heater to heat the atmosphere inside the enclosure and a device to increase the density of the air inside the enclosure.

4 The ozone generator may be operable to generate ozone within the enclosure to between 0.5 ppm and 200 ppm.
Other aspects of the invention will be appreciated by reference to the detailed description of the preferred embodiment and to the claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiment of the invention will be described by reference to the drawings thereof in which:
Fig. 1 is schematic diagram of the system of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
OF THE INVENTION
Referring to Fig. 1, there is generally illustrated a system 10 for disinfecting a greenhouse enclosure or greenhouse related enclosure 12. The system 10 includes an ozone generator 14 which generally employs a cryogenic storage tank 16 filled with liquid oxygen, a vaporizer 18 and a regulator 20.
Depending upon the size of the enclosure 12, one or more generators may be employed.
For ease of transport to other enclosures, the generator 14 may be mounted on a trailer or the like, although it is also contemplated that the generator may be at a fixed location.
Leading from the generator 14 is an ozone delivery conduit 22, such as a hose, pipe or the like, for delivery of gaseous ozone from the generator 14 into the enclosure 12. The ozone delivery conduit 22 may be a permanent fixture attached to the enclosure 12, but it is also contemplated that the conduit may be removable. The conduit may have a single opening at the end inserted into the enclosure 12, but may also include at the end inserted into the enclosure 12 several pores to evenly distribute the ozone in the enclosure.
The system 10 also includes a conventional ozone concentration measuring device or sensor 24 for monitoring and measuring ozone concentration within the enclosure 12. Depending upon the size of the enclosure 12, one or more sensors may be used. If a plurality of sensors are used, preferably they are evenly dispersed throughout the enclosure 12 to provide an accurate ozone concentration level. The ozone concentration measuring sensor 24 is operable to communicate with a computer processing unit 26 via a wireless or wired connection. Additionally, computer processing unit 26, which may reside in a cloud, is also operable to communicate with the generator 12 to control the production of ozone via a wireless or wired connection. Preferably, computer processing unit 26 is operable to communicate with a remote mobile device 27, such as a smartphone, tablet, laptop computer or the like, which enables the user to monitor and control the system 10 without having to be onsite. It is also envisioned, that the computer processing unit itself, may also be a remote mobile device. In a wireless application, both the generator 14 and sensor 24 are configured to send and receive communication signals wirelessly either through wifi, bluetooth, wlan and the like.
To begin operation of the system 10, a user simply inserts the ozone delivery conduit 22 from the ozone generator 14 into the enclosure 12. Typically, the ozone delivery conduit 22 is fed into a pre-existing opening in the enclosure 12, such as a door, a window a vent or the like. Some greenhouse enclosures 12 employ a CO2 injection system 28 that is operable to circulate CO2 evenly throughout the enclosure. In such enclosures, the ozone delivery conduit 22 from the ozone generator 14 may simply be connected to the CO2 injection system 28 to advantageously evenly distribute the ozone throughout the enclosure 12.

Before operating the system 10, people, and any desirable animals or the like, are excluded from the enclosure 12 and the enclosure is substantially sealed so that air inside the enclosure is substantially prevented from escaping. Here, remaining doors, windows, vents and the like are closed and other openings are covered with plastic, duct tape and the like.
Once the enclosure 12 is substantially sealed, the generator 14 is initiated to produce gaseous ozone in order to create an ozone enriched atmosphere within the enclosure. Ozone is continually fed into the enclosure 12 and the concentration is continually monitored so that an effective ozone concentration is reached in the enclosure. The effective ozone concentration, as those skilled in the art will appreciate, will vary depending upon the target organism to be eradicated. Generally, an effective ozone concentration is between 0.5 ppm to 200 ppm, with lower order organisms, such as fungus, requiring a lower concentration, and higher order organisms, such as rodents, requiring a higher concentration.
Since the enclosure 12 is sealed, air is maintained inside the enclosure and the ozone concentration will steadily rise to the desired level and be circulated throughout the enclosure penetrating into corners and smaller spaces. To increase ozone circulation throughout the enclosure 12, an air movement device 30, such as a fan, a blower or the like, or plurality of air movement devices may be employed inside the enclosure to circulate the ozone. Such air movement devices may be moveable or permanently fixed to the enclosure or CO2 injection system.
Once the effective ozone concentration is met, the generator 14 may be shut down to monitor the breakdown of the ozone gas in the enclosure 12. This will indicate if the reaction is very active or if there is still Volatile Organic Content (VOC) still present in the enclosure 12. If VOC is still present in the enclosure 12, additional ozone may be generated and fed into the enclosure to reboot the disinfection process.
Generally, it is contemplated that the time required for disinfection, the effective period of time, will be between 0.25 to 32 hours. As those skilled in the art will appreciate, the effective period of time will depend on a number of factors, such as the size of the enclosure 12, the target organism to be eradicated and time of day when the system 10 is operated. After expiry of the effective period of time, the doors, windows, vents and the like are open to deplete the ozone inside the enclosure 12 to a level safe for public access. Here, the air movement device may be employed to expedite the process. Once the ozone concentration inside the enclosure 12 is at a level safe to the public, generally at a level of 0.1 ppm, or less the public is then signaled that it is safe to enter. A visible signal, such as a strobe light 32 may simply be used.
Reaction of free oxygen atoms from the ozone with the pathogens is somewhat increased, and hence the effectiveness of the present invention, when the humidity inside the enclosure 12 is relatively high compared to a lower humidity.
To that end, the system 10 may include a conventional humidifier 34 or the like, or a plurality of humidifiers or the like, located inside the enclosure 12 to increase the humidity of the atmosphere inside the enclosure, if required. Ideally, the relative humidity inside the enclosure 12 should be greater than 30%
Additionally, reaction of free oxygen atoms from the ozone with the pathogens is somewhat increased, and hence the effectiveness of the present invention, when the temperature inside the enclosure 12 is higher compared to a lower temperature. To that end, the system 10 may include a conventional heater 36 or the like, or a plurality of heaters or the like, located inside the enclosure 12 to heat the atmosphere inside the enclosure, if required. Ideally, the temperature inside the enclosure 12 should be between 20 C and 40 C.

Furthermore, reaction of free oxygen atoms from the ozone with the pathogens is somewhat increased, and hence the effectiveness of the present invention, when the atmospheric pressure inside the enclosure 12 is higher compared to a lower atmospheric pressure. Increasing the pressure inside the enclosure 12 may be accomplished through increasing the heat inside the enclosure with the heater or the like or alternatively, through increasing the density of the air in the enclosure by forcing air into the enclosure through conventional means, if required.
In a typical system 10 for practicing the method of the invention, ozone generation, humidity control, temperature control and density of air inside the enclosure 12 and subsequent adjustments would be controlled by the computer processing unit 26.
The system 10 can be remotely activated, controlled and monitored via the remote mobile device 27 which is in communication with the computer processing unit 26, either through wired or wireless communication so that the user can remotely commence control and monitor the disinfection process. The system 10 may have a local or remote visual or sound indication of operation so that personnel will be warned when the system is in use and that it is not safe to enter the disinfection area.
It will thus be seen that a new and novel method and system for disinfecting a greenhouse and greenhouse related enclosures has been illustrated and described and it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention.

Claims

What is claimed is:

1. A method of disinfecting a greenhouse enclosure or greenhouse related enclosure, the enclosure including a CO2 injection system operable to circulate CO2 throughout the enclosure, the method comprising:
providing an ozone generator;
inserting an ozone delivery conduit from said ozone generator into the CO2 injection system;
restricting access to the enclosure to prevent public access and substantially sealing the enclosure such that air inside the enclosure is substantially prevented from exiting;
creating an ozone enriched atmosphere within the enclosure by generating gaseous ozone into the enclosure to an effective ozone concentration;
monitoring ozone concentration within the enclosure;
circulating said ozone enriched atmosphere within the enclosure; and after expiry of an effective period of time, depleting said ozone within the enclosure to a level safe for public access.

2. The method of claim 1 wherein circulating said ozone enriched atmosphere within the enclosure comprises operation of an air movement device.

3. The method of claim 1 further comprising signally to the public when said ozone concentration within the enclosure is reduced to a maximum level of 0.1 ppm.

4. The method of claim 3 wherein signally comprises operation of a strobe light.

5. The method of claim 1 wherein said effective ozone concentration is between 0.1 ppm and 200 ppm.

6. The method of claim 1 wherein said effective period of time is between 0.25 to 32 hours.

7. The method of claim 1 further comprising increasing the relative humidity within the enclosure during disinfection.

8. The method of claim 1 further comprising increasing the temperature within the enclosure during disinfection.

9. The method of claim 1 further comprising increasing the atmospheric pressure within the enclosure during disinfection.

10. The method of claim 1 wherein monitoring the ozone concentration within the enclosure comprises providing an ozone concentration measuring device operable to communicate with a computer processing unit.

11. The method of claim 10 wherein said computer processing unit is operable to communicate with said generator to control ozone produced by said generator.

12. The method of claim 10 wherein said computer processing unit is operable to communicate with a remote mobile device.

13. The method of claim 10 wherein said computer processing unit comprises a remote mobile device.