DESC:ULTRAVIOLET RADIATION SYSTEM FOR DISINFECTING SURFACES AND AIR IN ENCLOSED AREA
Field of the invention:
The present invention relates generally to ultraviolet radiation and more particularly, to an ultraviolet radiation system for disinfecting surfaces and air in enclosed area.
Background of the invention:
There are existing systems in the market which are trolley mounted but these devices are mainly used for surface disinfection. Limited air disinfection is achieved by these devices during passage of UV through air. The usage of these systems is not possible in presence of human or during human occupancy; these devices do not have this sensing mechanism also in place and simply use the timer circuit to switch ON/OFF the UV lamps. The user needs to take care of avoiding the direct exposure to UV during its working.
The US Patent no. US8907304B2 describes about the ultraviolet autonomous trolley for sanitizing aircraft. This trolley shall have at least two arms that can be extended to sanitize the surfaces inside an aircraft which are mounted on a trolley or a cart that can be manually moved through the aircraft aisle. The arms are mainly directed to sanitize the seats in the aircraft. The battery provided can power the lamps and the arms can be moved over the surfaces of the seat independently. The arms can be extended over the seat surfaces independently and can be foldable so that lamps can reach to different surfaces of the air craft seats and area above the seats. The system can include sensor for measuring the distance and or power of the UV lamps relative to the surfaces for controlling the UV energy delivered to the surface. The system can be moved automatically or manually through the aircraft aisle. The system described in the patent is only for the surface disinfection, and disinfection of air in the enclosed area is achieved through the fan provided can circulate air and expose it to the UVC for disinfection. In addition the lamps can also have provision of ozone formation for removal of odor. Both these odor removal and air disinfection cannot be achieved during Human occupancy. Another patent number US2014/0241941A1 also describes the Ultraviolet trolley for sanitizing aircraft mainly cabin interior surfaces with UVC light. Both above patents describe the devices which are mainly targeted towards use in aircrafts. The devices mentioned in these patents work in both applications of air and surface disinfection, but do not take care of human safety which is left on the user. Both these devices are targeted towards application in air craft and also make use ozone for odor removal.
The US patent no. US2005/0212239A1 describes a food service cart with a self-contained air disinfection system. This device can operate for predefined time intervals. The cart has at least one door through which the food can be stored and a switch connected to the door for switching off the UV lamp when the door is opened. The arrangement ensures the safe UV operation to avoid UV exposure to Human and enables the device to work during human occupancy. The above two devices do not ensure such safety and is totally left with user. But since this device is enclosed cart its use is limited to disinfection of the interior surfaces of the cart and air inside. The device claimed in this patent has an enclosure and takes care of human safety by using interlocking switch with the door of the system. This device has a specific application of food service trolley disinfection and cannot be used for larger enclosed areas like rooms, offices etc.
The US Patent no. US2014/0044590A1 describes a sterilization system consisting of a mobile emitter, a sensing subsystem and a data logging subsystem. The emitter has one or more UV emitting lamps or devices. The sensing system comprises at least one remote UV sensor and at least one door sensor. The door sensor comprises a safety shut off door detector and may contain an emergency stop detector and arming detector to protect people from being exposed to UV energy. The system has a remote control for starting, stopping and setting system parameters which include but are not limited to: treatment time, dosage, room size, room number, unit number, floor, facility name, operator name, operator identification number, password, default dosage values, dosage, and patient identification number. The number of treatments per unit of time can be maximized because of the use of incident light measurement. The patent discloses sterilization system that takes care of human safety but cannot work during human occupancy and can work for surface disinfection and limited air disinfection.
Hence, the prior art devices are not powerful air disinfection devices as the air may or may not come in contact with UV. Secondly, air disinfection cannot be during human occupancy as these systems need to be used in unoccupied spaces.
Accordingly, there exists a need to provide an ultraviolet disinfection system that overcomes the above-mentioned drawbacks in the prior art.
Objects of the invention:
An object of present invention is to provide a single system for effectively disinfecting surfaces and air in an enclosed area using ultraviolet radiation.
Another object of present invention is to provide an ultraviolet radiation system for disinfection of surfaces as well as air in an enclosed area that can be safely used during human occupancy.
Yet another object of present invention is to provide an ultraviolet radiation system that can be operated manually and automatically for disinfecting surfaces and air in an enclosed area
Yet another object of present invention is to provide an ultraviolet radiation system that can be used effectively in both surface disinfection mode and air disinfection mode.
Summary of the invention
The present invention discloses an ultraviolet radiation system for surface disinfection as well as for disinfection of air in an enclosed area. The system comprises an ultraviolet emitter assembly fitted on a wheeled base. The ultraviolet emitter assembly includes a single UV emitter or a plurality of UV emitters arranged in circular manner. Each UV emitter from the plurality of ultraviolet emitters is fitted with a reflector. The reflector is fitted with a rotating means for rotating each reflector around the UV emitter through 180° and back. In the air disinfection mode, the reflectors are rotated to enclose the ultraviolet emitters, thereby forming an ultraviolet concentrated air passage there between. An axial fan unit is fitted at the bottom of the emitter assembly for drawing air from the enclosed area to pass through the ultraviolet concentrated air passage. A top cover provided with a slot for air passage there through, is fitted on the ultraviolet emitter assembly. The top cover is and fitted with a motion sensor thereon for detecting any motion in the enclosed area. A control unit is operably connected to the motion sensor, the emitter assembly, the gear assembly, and the axial fan unit, for receiving and detecting signal from the motion sensors and controlling the switching ON and OFF of emitters accordingly, and for controlling the rotation of reflectors, movement of wheeled base and operation of axial fan assembly depending upon the mode of operation. The control unit rotates the reflectors to enclose the emitters in the air disinfection mode thereby creating a concentrated UV zone and switches ON the axial fan unit to let air in the enclosed area continuously pass through the concentrated UV zone. In the surface disinfection mode, the control unit switches ON the emitters after a preset time gap to allow the operator to move to the safe distance for protection against UV exposure.
Brief description of the drawings:
The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein
Figure 1Aand 1B show top view of emitters and reflectors with gear system, in open and closed condition respectively, in accordance with the present invention;
Figure 2Aand 2B show front view of emitters and reflectors with gear system, in open and closed condition respectively, in accordance with the present invention;

Figure 3 shows an ultraviolet radiation system with six emitters, in accordance with one of the embodiment of the present invention; and
Figure 4 shows an ultraviolet radiation system with one emitter, in accordance with one of the embodiment of the present invention; and
Figure 5 shows schematic arrangement of gear system of ultraviolet radiation system, in accordance with the present invention.
Detailed description of the invention:
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with the prior art techniques and approaches are overcome by the present invention as described below in the preferred embodiment.
The present invention relates to an ultraviolet radiation system for disinfecting surfaces as well as air in an enclosed area, even in the presence of humans. The system works in a surface disinfection mode and an air disinfection mode. In the surface disinfection mode, the system makes use of a motion sensing circuit. In this mode the system can be moved from one place to other and can be operated either automatically or manually. In both type of operations, it gives 30 sec. time before the UV emitters start so that the operator can go out of the room. Based on log reduction required, predetermined time interval options can be selected for system operation. If any intervention occurs during operation of the system or any motion is detected during system operation, the UV emitters are switched off and the system requires manual restart. This way safety of the operator or any other human is taken care of. In air disinfection mode, the system works as an enclosed system and can be used during human occupancy also. In this mode, a UV zone is created by rotating the reflectors and arranging all the emitters at the center with reflectors around them. Air in the enclosed area is passed through the UV zone. A separate fan arrangement is provided for passage of air through the UV zone. The rotation of reflectors can be automatic or manual. In this mode, the motion detection circuit is not needed as the reflectors cover the centrally arranged UV emitters. In this mode the system can be moved either automatically or manually and kept in any part of the enclosed area or work area to work as air disinfection device. Appropriate room volume selection options can be used to get the desired air disinfection in the predetermined time interval. The mechanical arrangement along with microcontroller based sensing and timer circuit makes this system a powerful device to use in both surface disinfection mode and air disinfection mode.
This present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description below. Table 1 below enlists the reference numerals and corresponding components.
Table 1
Ref No. Component Ref No. Component
5 Wheels 70 Sun gear
10 Base 80 Planet gear
20 Reflector 85 Gear Assembly
25 Reflector extension 82 Geared motor
30 UV emitter 84A Upper gear set
35 Emitter assembly 84B Lower gear set
40 Control unit 86 Drive shaft
50 Top cover 88 Bearing plate
55 Motion sensor 90 Axial fan unit
60 Axial fan arrangement
Referring to figures 1 to 3, an ultraviolet radiation system (100) (hereinafter referred as, “the system (100)”) for disinfecting surfaces and air in enclosed area is shown. The system (100) comprises of an emitter assembly (35), a rotating means, a control unit (40), an axial fan unit (90) and a wheeled base (10). The system operates in a surface disinfection mode and in an air disinfection mode.
The emitter assembly (35) is fitted on the wheeled base (10) with a top cover (50). The emitter assembly (35) consists of a plurality of ultraviolet emitter (30). In an embodiment, when the emitter assembly (35) consists of more than one emitter (30), the emitters (30) are arranged in a circular manner on the wheeled base (10). Each ultraviolet emitter (30) from the plurality of ultraviolet emitters fitted with a reflector (20). The top cover (50) is fitted with at least one motion sensor (55) for detecting motion in the enclosed area.
The reflectors (20) are coupled with the rotating means for rotating each reflector (20) through 180° and back around the emitter (30).
In an embodiment, when the emitter assembly (35) is consisting of one UV emitter (30), the reflector (20) is a cylindrical metallic enclosure preferably of aluminum, having inner surface reflective. In this embodiment of single UV emitter, in the surface disinfection mode, the reflector (20) is removed while in the air disinfection mode, the UV emitter (30) is covered with the reflector (20) to form the ultraviolet concentrated air passage at the inner side of the reflector (20).
In another embodiment, when the emitter assembly (35) is consisting of plurality of UV emitter (30), the reflector (20) is a curved metallic surface preferably of aluminum, having inner surface reflective and partially covering the UV emitter (30). In this embodiment of plurality of UV emitters (30), each reflector (20) is fitted with a reflector extension (25) for covering a gap that is formed between two adjacent reflectors (20) in closed condition. The reflector extension (25) is of any shape selected from L shape, V shape and C shape. In this embodiment wherein the system, (100) consists of the plurality of UV emitters (30), in the surface disinfection mode, the reflectors are rotated to uncover the emitters (35) to spread/ reflect the ultraviolet light in the enclosed area. In the air disinfection mode the reflectors (20) are rotated to enclose/ cover the ultraviolet emitters (30) from outer side thereby forming an ultraviolet concentrated air passage at the inner side (closed condition). Thus the reflectors (20) act as a light spreader in surface disinfection mode and act as a concentrator in air disinfection mode.
The number of ultraviolet emitters (30) from the plurality of ultraviolet emitters is restricted by the radius of the circle on which the ultraviolet emitters (30) are arranged, the size of reflectors (20) and the space required by the rotating means. In a preferred embodiment, the number of emitters is six. However, more UV emitters can be added based on the factors as above (the radius of the circle on which the ultraviolet emitters (30) are arranged, the size of reflectors (20) and the space required by the rotating means.)
The axial fan unit (90) is fitted at the bottom of the emitter assembly (35) for drawing air from the enclosed area to pass through the ultraviolet concentrated air passage. The ultraviolet concentrated air passage is formed in closed condition of the emitter assembly, in air disinfection mode.
The control unit (40) is operably connected to the emitter assembly (35), the motion sensor and the rotating means. The control unit includes electronic ballasts for running UV emitters (30), a control circuit (not shown) to control system functions, a digital display (not shown) for giving visual indications, a battery pack (not shown) for DC power supply or retractable cable for giving external AC supply. The control unit (40) receives and detects signal from the motion sensors (55) and controls the switching ON and OFF of emitters (30), rotation of reflectors (20), movement of wheeled base (10) and operation of axial fan assembly (90).
In an embodiment, the rotating means is a gear assembly (85) fitted to the top cover (50). The gear assembly (85) consists of an upper gear set (84A) and a lower gear set (84B), each including a sun gear (70) and a plurality of planet gear arranged on a drive shaft (86). Each planet gear (80) from the plurality of planet gears is coupled to the reflector (20). The drive shaft (86) is driven either with a gear motor (82) or with a handle like mechanically operated arrangement.
The system (100) is operated in any one mode selected from the surface disinfection mode and the air disinfection mode. The control unit (40) provides two way protection in surface disinfection mode. When the system (100) is in surface disinfection mode, the UV emitters (30) are switched ON after a preset time gap so that the operator can move to the safe distance for protection against UV exposure, within the preset time period. On detection of any motion in the enclosed area, the emitters (30) are switched off by the control unit (40) to avoid any UV exposure during system operation. In surface disinfection mode the system (100) is operated for predetermined selected time based on specific microorganism, e.g. SARS CoV-2.
When the system (100) is operated in the air disinfection mode, the reflectors (20) with reflector extension (25) are rotated to enclose the emitters (30) thereby creating a concentrated UV zone and the axial fan unit (90) is switched ON to let air in the enclosed area continuously pass through the concentrated UV zone. Thus as the ultraviolet emission is not emitted outside, the system (100) works as an enclosed system and can be used during human occupancy also. The motion detection circuit is deactivated during air disinfection mode. In air disinfection mode, the system (100) can be moved and kept in any part of the enclosed area or work area to work as air disinfection device. The motion can be either automatic or manual. Appropriate room volume selection options can be used to get the desired air disinfection in the predetermined time interval.
Experimental examples:
1. Surface Disinfection mode:
Determination of Log inactivation of Bacterial species Staphylococcusaureus(ATCC 6538P) was done using the UV radiation system (100) in surface disinfection mode. The procedure involved placing Replica of different materials, spreading challenge microorganism Staphylococcusaureus (ATCC-6538P) on the materials & keeping it in UV radiation exposure zone of system (100) at different distances for a predetermined amount of time of 200 Sec. (The calculated time for surface disinfection or inactivation of challenge microorganism on the surface is 200 sec. at 2 meter distance from UV device).The challenge microorganisms used to validate the system (100) were cultured and analysed by the microbiology laboratory as specified in Standard Methods. The concentration of microorganisms measured before and after the UV exposure provides response log inactivation of the microorganisms from exposure to UV light. Sampling was done at different sites including top and bottom surface in the selected rooms. Table 2 below shows the bacterial count on the surface under examination in CFU, before and after the exposure of UV radiation by the system (100).
Table 2
Surface Sr. no. Distance from the UV device Sample testing site Bacterial Count/ CFU Log inactivation
Before UV exposure after UV Exposure
Artificial Leather 1 0.5 m site 1 top 6 x 1010 1 x 104 > log 6
2 0.5 m site 2 floor 6 x 1010 6 x 105 > log 5
3 1.0 m site 3 top 2 x 1010 2.4 x 106 > log 3
4 1.0 m site 4 floor 2 x 1010 1.2 x 107 > log 5
5 2.0 m site 5 top 4 x 1010 4.8 x 107 > log 2
6 2.0 m site 6 floor 4 x 1010 3 x 107 > log 3
Metal (SS316) 7 0.5 m site 7 top 8 x 109 7 x 102 > log 7
8 0.5 m site 8 floor 8 x 109 6 x 103 > log 6
9 1.0 m site 9 top 1.2 x 1010 1 x 103 > log 7
10 1.0 m site 10 floor 1.2 x 1010 2.6 x 104 > log 5
11 2.0 m site 11 top 2 x 1010 1.2 x 103 > log 7
12 2.0 m site 12 floor 2 x 1010 1 x 104 > log 6
Table 2 clearly shows that the UV radiation system (100) in surface disinfection mode effectively disinfects various surfaces by considerably reducing the bacterial activity on the surfaces.
2. Air Disinfection mode:
Determination of percentage inactivation of Bacteria using the UV radiation system (100) in air disinfection mode was done by settle plate method. The procedure involved steps as below:
? The Soybean Casein digest agar media plates were kept open at the site for a period of one hour to find out the pre-treatment count of bacteria in the air. Bacteria in air settle down on open agar plate in the exposure time.
? The site was exposed to ultraviolet light using the system (100) for 45 minutes and the post-treatment bacteria count was taken.
The measured concentration of bacteria before & after in Air would provide the response or percentage inactivation of the bacteria due to the system (100) in air disinfection mode.
Table 3 below shows results of percentage inactivation of bacteria inactivation by the system (100) in air disinfection mode.
Table 3

Sr.
no Site Time Interval Pre treatment count
(cfu/cm2) Exposure time
(Hr) Post treatment count (cfu/cm2) Percentage reduction
(%)
1. Near Floor 1 Hr 16 45 min 1 93.75
2. Near ceiling 1 Hr 14 45 min < 1 100
Percentage inactivation of Bacterial flora in air by the system (100) operated in air disinfection mode is > log 1 after 01:00 Hr time interval.
Advantages of the invention:
The system (100) provides efficient air disinfection mode and can work as a standalone unit for both surface disinfection as well as air disinfection.
The system (100) provides maximum protection in surface disinfection mode due to timer delay and motion detection sensor based control.
The system (100) in air disinfection mode forms concentrated UV zone enabled by reflector rotation.
The system (100) in air disinfection mode gives improved efficiency due to passing of air in this concentrated UV zone using the axial fan arrangement.
The system (100) in air disinfection mode can be used during human occupancy due to the enclosed UV zone formed by the reflectors.
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the scope of the invention

,CLAIMS:We claim:
1. An ultraviolet radiation system (100)for operating in a surface disinfection mode and in an air disinfection mode for disinfecting air in an enclosed area, the ultraviolet radiation system (100) comprising:
an emitter assembly (35) fitted on a wheeled base (10), the emitter assembly (35) having a plurality of ultraviolet emitters arranged in a circular manner, each ultraviolet emitter (30) from the plurality of ultraviolet emitters fitted with a reflector (20);
a rotating means for rotating each reflector (20) through 180° and back around the emitter (30), wherein in the air disinfection mode, the reflectors (20) on rotation are adapted to enclose the ultraviolet emitters (30) from outside, thereby forming an ultraviolet concentrated air passage there inside;
an axial fan unit (90) fitted at the bottom of the emitter assembly (35) for drawing air from the enclosed area to pass through the ultraviolet concentrated air passage;
a top cover (50) fitted on the ultraviolet emitter assembly (35), the top cover (50) provided with a slot for air passage there through and fitted with a motion sensor (55) thereon; and
a control unit (40) operably connected to the motion sensor (55), the ultraviolet emitter assembly (35), the rotating means, and the axial fan unit (90), for receiving and detecting signal from the motion sensors (55) and controlling the switching ON and OFF of the plurality of ultraviolet emitters accordingly, and for controlling the rotation of the reflectors (20), movement of wheeled base (10) and operation of axial fan assembly (90) depending upon the mode of operation.
2. The ultraviolet radiation system (100) as claimed in claim 2, wherein the reflector (20) is a cylindrical metallic enclosure preferably of aluminum, for the emitter assembly (35) consisting of a single emitter (30).
3. The ultraviolet radiation system (100) as claimed in claim 2, wherein the reflector (20) is a curved metallic surface preferably of aluminum, for the ultraviolet emitter assembly (35) consisting of more than one emitters (30).
4. The ultraviolet radiation system (100) as claimed in claim 1, wherein a reflector extension (25) having of any shape selected from L shape, V shape and C shape is attached on one side of the reflector (20) to cover a gap between two adjacent reflectors (20) that is formed when the reflectors (20) rotate to enclose the ultraviolet emitters (30).
5. The ultraviolet radiation system (100) as claimed in claim 1, wherein the rotating means is a gear assembly (85) including an upper gear set (84A) and a lower gear set (84B); each gear set (84A, 84B) including a sun gear (70) and planet gears (80) coupled with the reflectors (20) for rotation thereof, the gear assembly (85) arranged on a drive shaft (86) and fitted between the top cover (50) and the wheeled base (10).
6. The ultraviolet radiation system (100) as claimed in claim 6, wherein the drive shaft (86) is operated either manually or electrically.
7. The ultraviolet radiation system (100) as claimed in claim 1, wherein the control unit (40) rotates the reflectors (20) to enclose the emitters (30) in the air disinfection mode, thereby creating a concentrated UV zone and switches ON the axial fan unit (90) to let air in the enclosed area continuously pass through the concentrated UV zone.
8. The ultraviolet radiation system (100) as claimed in claim 1, wherein the control unit (40) switches ON the emitters (30)after a preset time gap, in the surface disinfection mode.
Dated this 27th day of January, 2022

Ashwini Kelkar
(Agent for Applicant)
(IN/PA-2461)