as) United States
`a2) Patent Application Publication 0) Pub. No.: US 2005/0163648 Al
`
` LIANG (43) Pub. Date: Jul. 28, 2005
`
`
`US 20050163648A1
`
`(54) METHOD AND APPARATUS FOR
`STERILIZING AIR IN LARGE VOLUMESBY
`RADIATION OF ULTRAVIOLET RAYS
`
`(52) U.S. Che vices 422/1; 422/24; 422/121; 422/186;
`422/305
`
`(76)
`
`Inventor: MICHAEL Y. LIANG, ALAMEDA,
`CA (US)
`
`(57)
`
`ABSTRACT
`
`Correspondence Address:
`MICHAEL Y. LIANG
`218 CREEDON CIRCLE
`ALAMEDA,CA 94502 (US)
`
`(21) Appl. No.:
`
`10/707,919
`
`(22)
`
`Filed:
`
`Jan. 26, 2004
`
`Publication Classification
`
`(SL) Unt. C0 ec eeecccssssseneees A61L 2/00; A62B 7/08;
`BO1J 19/08; A61L 9/00
`
`A sterilizing method and apparatus for destroying live
`microorganismsincluding viruses in fluent material, such as
`air and water, in large volume. As a preferred embodiment
`of this invention, air is drawn, from the inlet 1, through the
`inlet filter unit 3 and into the circuitous sterilizing chamber
`10 that is irradiated by numbers of UV lamp tubes 15, and
`through the discharging filter unit 13 and then out through
`outlet 11. A sample window 12 is built
`in for quality
`supervision. Visual inspection windows 5 and UV sensors 6
`are provided for easy supervision and auto-control. The
`sterilizing chamber 10 also includes flow resistant reducing
`feature 7 and internal reflecting surfaces 9.
`
`Air Out
`
`
`
`EXHIBIT 1006
`
`EXHIBIT 1006
`
`1
`
`

`

`Patent Application Publication Jul. 28,2005 Sheet 1 of 6
`
`US 2005/0163648 Al
`
`Air Out
`
`FIG. 1
`
`2
`
`

`

`Patent Application Publication Jul. 28,2005 Sheet 2 of 6
`
`US 2005/0163648 Al
`
`Air Out
`
`
`
`
`
`
`
`
`
`SET
`PYht eeCd let>
`
`PI I hd
`oe 13
`PTFS
`| RSOn HDHD
`
`
`UTrhiheerl
`
`3
`
`

`

`PatentApplication Publication
`
`Jul. 28, 2005 Sheet 3 of 6
`
`US 2005/01 63 648A1
`
`Air Out iy
`
`
`ot1)
`os
`rYpaSissee
`
`
`Foyssetete:
`ud
`‘HEry) seees
`
`v4 ss : :peiBH ryBera re
`
`ooTS
`oe
`
`
`
`ibt) aers 1be+t rsptert fcat:
`
`
`
`
`4
`
`

`

`Patent Application Publication Jul. 28,2005 Sheet 4 of 6
`
`US 2005/0163648 Al
`
`1
`
`23 4
`
`5
`
`6
`
`7
`
`
`?
`Fe
`Ba|| air Out
`Air In pel es
`
`
`on
`
`5
`
`

`

`Patent Application Publication Jul. 28,2005 Sheet 5 of 6
`
`US 2005/0163648 Al
`
`6
`
`

`

`Patent Application Publication Jul. 28,2005 Sheet 6 of 6
`
`US 2005/0163648 Al
`
`Out
`
`18
`
`Oo
`\
`\/
`
`11
`49
`
`13
`O
`4
`4 AI
`1
`47 a4 aaaaA
`PSP
`yyy 7
`|
`In
`ee\V Ze
`56
`46
`
`3/
`
`1
`
`ie OOO ~O~5
`Y/P 2-98 2
`OBEN G
`\oe -)
`a a 12
`AOD -y ~
`&
`Tt
`KEIO ND REE OG
`Dot
`5% Py gl
`e % \XS. OL0 / 23
`5 ASS OSS Zey
`oeg02 0”
`
`7
`
`9
`10
`
`°
`fs
`
`14
`
`A.
`
`>
`
`Hi
`
`Tea
`
`—|s
`
`|o\\7a.TNYou IPZOog/ /4
`
`6-G-o-
`
`SN
`
`7
`
`

`

`US 2005/0163648 Al
`
`Jul. 28, 2005
`
`METHOD AND APPARATUS FOR STERILIZING
`AIR IN LARGE VOLUMESBY RADIATION OF
`ULTRAVIOLET RAYS
`
`BACKGROUNDOF INVENTION
`
`{0001]
`
`1. Technical Field
`
`[0002] This invention is about an air sterilizing system,
`which uses intense ultraviolet (UV) irradiation to free air
`from live bacteria, viruses and other microorganisms. The
`method can also be applied to sterilize any fluent material,
`including gas, wateror other fluids, containing every kind of
`live microorganismsnaturally with or from biological agents
`used byterrorists or in warfare.
`
`[0003]
`
`2. Background
`
`[0004] The air transmission of harmful bacteria, viruses
`and other microorganismsis one of the most common causes
`of infectious disease in the world today. The deaths related
`to contaminated air are countless. Only influenza kills more
`than forty thousand people every year.
`
`[0005] The worldwide outbreak of SARS(caused by coro-
`naviruses) has become a serious global concern since Jan.
`2003. According to WHO, the amplification of transmission
`within well-equipped hospitals was a striking feature of
`SARS. In somecases, staff became infected despite wearing
`full protective equipment. Thus, although SARS is not
`thought to be an airborne infection, a disproportionately
`large amountof resources is needed to prevent transmission
`of airborne infections as compelling evidence states that
`aerosols and microdroplets with coronaviruses in air may
`play very important roles in SARStransmission.In the same
`way, many non-airborne harmful bacteria and viruses can
`become airborne when they are in the form of aerosols or
`microdroplets.
`
`the modern air-conditioned buildings
`[0006] Further,
`make microorganisms,including viruses, spread out to thou-
`sands of people easily and fast. In order to save energy, the
`buildings reuse most of the used air with only 10% to 20%
`fresh in. By using return air ducts, contaminated air that
`contains all respiratory microdroplets with million kinds of
`bacteria and viruses and toxic chemical gases emitted from
`building furnishings and consumerproducts, mixes together,
`like a cocktail,
`then is distributed to all people in the
`buildings. Every year, there are more than ten of thousand
`deaths with countless illnesses related to poor conditioned
`air in the world.
`
`[0007] Furthermore, if there is any terrorist distributing
`harmful biological agents, such as Bacillus Anthracis,in the
`form ofaerosols, via air conditioning systems of big build-
`ings, it will kill many people.
`
`[0008]
`
`3. Prior Art
`
`[0009] For preventing the air transmission of disease,
`many air purification devices have been created and pat-
`ented. But none of them was created for sterilizing air in
`large volumes and destroying more than 99.999% of the
`microorganisms in the air. For example, U.S. Pat. Nos.
`4,118,191, 4,210,429, 4,786,812, 4,806,768, 4,917,713,
`4,931,654, 4,990,311, 5,185,015, 6,264,888, 6,464,760,
`6,497,840, all
`these were designed with some orall of
`following components: blower,filter(s) and a few UV lamps,
`as small devices for use in rooms. All of them have a so short
`
`sterilizing path or a so small chamberthat the sterilizing
`effect
`is quite questionable. The weakest point of such
`apparatus is that they do not offer enough dosage of UV
`radiation to kill microorganisms. On the contrary, most of
`the above devices may have dangerous effects that they
`actually aerosolize microorganisms and blow them all over.
`
`[0010] Another approachisthesterilization of the cooling
`coil, filters or other parts of an air conditioning system by
`radiation of UV rays, such as U.S. Pat. Nos. 4,990,313,
`5,225,167. They can destroy bacterial accumulations on
`those parts. However,
`the filters do not catch all of the
`microorganisms. Thelatest filtration systems can only filter
`air on 0.12 micrometer (120 nm) size particles. But the
`diameter of bacteria and viruses are usually smaller than
`0.12 micrometer. Other weakness of such systemsis the high
`cost in purchase, use and maintenance.
`
`{0011] As other inventions like patent Publication No.
`U.S. 2003/0086848,
`they are mostly created for liquids.
`Neither can they solve the above-mentioned problems.
`SUMMARYOF INVENTION
`
`[0012] This invention is about an air sterilizing method
`and apparatusto destroy all live microorganismsinthe air in
`large volumesto satisfy the increasing needs for the pur-
`poses of anti infectious disease and anti-terrorism. These
`apparatus can sterilize either fresh air or return air before
`distribution. Or they can be usedto sterilize contaminated air
`before exhausting it to the environment. An apparatus can be
`designed for a killing rate higher than 99.999% by adjusting
`the number of UV lamps and extending the length of the
`circuitous sterilizing chamber(s). The employment of cir-
`cuitous chamber(s) is for the purpose of increasing exposure
`to UV radiation that is used to kill all live microorganisms
`that pass through the chamber.
`
`[0013] Since UV radiation at about 253.7 nm is very
`effective in killing microorganisms, the apparatus of this
`invention are very effective. These apparatus can be added
`onto existing air conditioning systems, or stand alone, for
`hospitals,
`biomedical,
`pharmaceutical,
`biotechnology,
`genetic research, universities, laboratories, food processing,
`semiconductor fabrication,
`industrial processing systems,
`governmental and military buildings, commercial buildings
`and any public buildings.
`
`[0014] This invention can also be applied to devise small
`sterilizing apparatus for transportation vehicles and residen-
`tial shelters.
`
`[0015] This invention can also be used to sterilizing all
`kinds of fluent material, especially water.
`BRIEF DESCRIPTION OF DRAWINGS
`
`[0016] FIG.1A fragmentary perspective view of the appa-
`ratus for sterilizing air in large volume by radiation of
`ultraviolet rays according to one preferred embodiment of
`this invention.
`
`{0017] FIG. 2 Depiction of a front elevation view and a
`top view of the apparatus for sterilizing air in large volume
`by radiation of ultraviolet rays of FIG.1.
`
`[0018] FIG. 3 Depiction of a front elevation view and a
`top view of the apparatus for sterilizing air in large volume
`by radiation of ultraviolet rays with substitution of UV
`lampsof FIG.1.
`
`8
`
`

`

`US 2005/0163648 Al
`
`Jul. 28, 2005
`
`[0019] FIG. 4 Depiction of a front elevation view and a
`top view of the apparatus for sterilizing air in large volume
`by radiation of ultraviolet rays according to another pre-
`ferred embodimentof this invention.
`
`[0020] FIG. 5 Depiction of a front elevation view and a
`top view of the apparatus for sterilizing water in large
`volume by radiation of ultraviolet rays according to a
`preferred embodimentof this invention.
`
`[0021] FIG. 6 Depiction of a front elevation view and a
`top view of the apparatus for sterilizing water in large
`volumebyradiation of ultraviolet rays according to another
`preferred embodimentof this invention.
`
`[0022] List of reference numbers for the major elements in
`the drawings.
`
`[0023]
`
`1 Inlet.
`
`[0024]
`
`2 Blower, fan, pump or other power unit.
`
`[0025]
`
`3 Inlet filter unit.
`
`[0026]
`
`4 UV lamp fixture.
`
`[0027]
`
`5 UV visual inspection window.
`
`[0028]
`
`6 UV sensor.
`
`[0029]
`
`7 Curved flow guiding interior.
`
`[0030]
`
`8 Housing of the apparatus.
`
`[0031]
`
`9 Interior mirror surface.
`
`[0032]
`
`10 Circuitous sterilizing chamber.
`
`[0033]
`
`11 Outlet.
`
`[0034]
`
`12 Inspection window or sample faucet.
`
`[0035]
`
`13 Outlet filter unit.
`
`[0036]
`
`14 Flow direction.
`
`[0037]
`
`15 UV lamptube.
`
`[0038]
`
`16 Maintenance door.
`
`[0039]
`
`17 Inlet valve.
`
`[0040]
`
`18 Outlet valve.
`
`DETAILED DESCRIPTION
`
`[0041]
`
`Modesfor carrying out the invention.
`
`[0042] Referring to FIG. 1, the basic construction of an
`apparatus for sterilizing air in large volume by radiation of
`ultraviolet rays in accordance with this invention is shown,
`including an exterior housing 8 with an air Inlet 1, an blower
`or fan and associated motor 2, an inlet filter unit 3, a
`roundabout UV germicidal sterilizing chamber 10 with UV
`visual inspection windows 5 and UV sensors 6 on it, an air
`outlet 11 with an inspection window 12 and an outletfilter
`13.
`
`[0043] The air inlet 1 is preferably positioned on the
`lowest part of the sidewall of the housing. Since air inlet 1
`may connect to a fresh and/or return air duct (not shown,) the
`opening size and shape of the inlet 1 may matchthe air duct.
`However, it shall be decided by the volumeof air to be
`sterilized when it is for new installation. Thus, the size of
`inlet 1 shall be the sameasthe sterilizing chamber 10 and
`outlet 11.
`
`[0044] As better shown in FIG.2, within the inlet 1, there
`is preferably a blower or fan and associated motor2 to give
`air enough powerto go though the apparatus. Connected to
`the inlet 1, there is an inlet filter unit 3 so that all air drawn
`through the inlet 1 must pass throughtheinletfilter 3 before
`entering the chamber 10. The basic function of the inletfilter
`unit 3 is intercepting and retaining any fairly large particles
`to protect UV lamp tubes 15 in said chamber 10 whereair
`flows from the inlet filter unit 3 to the outlet filter unit 13.
`
`Theair outlet 11 is preferably positioned on the top
`[0045]
`of the housing 8 so that the sterilized discharging air can
`easily goes into the air distribution duct (not shown) that
`leads to every roomsin a building, or into air exhaust pipe(s)
`(not shown) to the air outside. Between the sterilizing
`chamberandthe outlet, there is an outletfilter unit 13. The
`purposeof this filter is to prevent particles from getting into
`the air distribution duct. So, the outlet filter unit 13 can be
`designed according to the requirements of application, from
`normalfilters to HEPA/ULPAfilters, preferably HEPAfilters
`for most of the applications. The outlet filter unit is also
`comprised of a catalytic filter to convert ozone into oxygen.
`Onthe outlet 11, there is an inspection window 12 for taking
`air samples for live microorganisms inspection to supervise
`sterilizing effect and air quality.
`
`In the sterilizing chamber 10, which is constructed
`[0046]
`basically by the six sides of the housing 8, there is always
`a curved (circular) flow guiding interior 7 to make a smooth
`roundabout wherever the air flow turns its direction in the
`chamber 10 to reduce flow resistance. The interior surfaces
`9 ofthe sterilizing chamber 10 is made with antiultraviolet,
`light reflecting material with mirror surface to increase the
`interiorreflection and thus increase the UVsterilizing effect.
`The length and/or the numberof roundabouts of the chamber
`10 can be reduced or increased according with the number
`of UV lamps to be installed. The opening size of the
`sterilizing chamber 10 is mainly decided by the volume of
`air to be sterilized. Normal sizes include, but not limit to,
`U'x1', 1'x2', 2'x2', 2'x3', 3'x3', 3'x4', 4'x4’.
`
`[0047] Positioned in the circuitoussterilizing chamber 10,
`are numbers of UV lamp tubes 15. These UV lamps pen-
`etrate through the walls of the chamber 10 from outside of
`the front and back walls of the housing 8. Their fixtures 4
`and wiringsare fixed outside the housing 8 so that it is easy
`to perform lamp exchange periodically or other mainte-
`nance. In a preferred embodimentof this invention, the UV
`lamps 15 are preferably single end (but can be double ends)
`tube-shape non-ozone germicidal lamps that emit UV radia-
`tion mainly at about 253.7 nm, which is the most sensitive
`UVradiation to all microorganisms. For easily supervision
`UV lamps, there are preferably one UV visual inspection
`window 5 and one UV sensor 6 in every section the
`sterilizing chamber 10.
`
`[0048] The fundamental difference of this invention from
`prior art methods and apparatus that were thought having the
`ability to kill all of microorganisms with only one, two or
`three UV lamps in a wink, is the UV radiation exposure
`intensity. The basic formulais that the product (UV radiation
`value) of UV power multiplying exposure time must be
`higher than the UV death value of any microorganisms. In
`other words,the sterilizing dosage of UV radiation should be
`high enough that
`there will not be any microorganism
`survived.
`
`9
`
`

`

`US 2005/0163648 Al
`
`Jul. 28, 2005
`
`In order to accomplish this goal, a circuitous ster-
`[0049]
`ilizing chamber 10, which can increase both the traveling
`time of the sterilized air and the number of UV lamps
`installed, is employed. In order to get ideal UV intensity, the
`distance between any two UV lampsis preferably about 3"
`to 1'. They can line up in any pattern. In the preferred
`embodimentof this invention, there are 98 UV lamptubes
`15 in two rowsalongthe circuitous sterilizing chamber 10.
`These lamps are fixed on both front and rear side of the
`chamber 10.
`Increasing the number of UV lamps can
`increase the sterilizing power of the apparatus. The length
`and roundabouts of the chamber 10 can also be increased to
`get more space to install UV lamps.
`
`[0050] FIG. 3 illustrates an apparatus with a substitution
`of UV lamps of FIG. 1. In this preferred embodimentof the
`invention, the UV lamptubes 15 here are preferably double
`end tube-shape non-ozone germicidal lamps, lining up in
`any pattern. The incomingside of the lamp sockets shall be
`covered with airflow guiding plates (not shown) to reduce
`airflow resistance. These kinds of UV lamps have the
`characteristics of higher UV power output and lowercost. In
`order to perform maintenance, there are five maintenance
`doors with anti-ultraviolet sealing on the edges in this
`embodiment.
`
`[0051] FIG. 4 depicts another preferred embodiment of
`this invention. This embodimentis with a different orienta-
`tion. To meet different
`installation needs,
`the inlet 1 is
`preferably positioned on the other side of the air outlet 11
`and the UV lampfixtures 4 only installed on one side of the
`housing 8.
`
`[0052] FIG. 5 depicts an apparatus for sterilizing water in
`large volumebyradiation of ultraviolet rays according to a
`preferred embodimentof this invention. Water goes through
`the inlet valve 17, inlet 1, and inlet filter unit 3 then into the
`circuitous sterilizing chamber 10. The distance between any
`two UV lampsis preferably about 2" to 6". The sterilized
`water discharges through outlet filter unit 13, outlet 11, and
`then outlet valve 18. There is sample faucet 12 for water
`quality supervision.
`
`[0053] FIG. 6 depicts an apparatus for sterilizing water in
`large volumeby radiation of ultraviolet rays according to
`another preferred embodiment of
`this invention. This
`embodiment constructs a spiral-sterilizing chamber 10,
`which has lower flow resistance, and more space to install
`UV lamps. The distance between any two UV lampsis about
`2" to 6". The sterilized water discharges through outlet filter
`unit 13, outlet 11, and then outlet valve 18. There is a sample
`faucet 12 for water quality supervision.
`
`[0054] Other alternate embodiments may be devised with-
`out departing from the spirit or the scope of the invention.
`For example, the apparatus depicts in FIG. 6 can be adapted
`for sterilizing air, and small apparatus can be devised for
`sterilizing transportation vehicles and residential shelters.
`
`1. A Methodforsterilizing fluent material in large volume
`by radiation of ultraviolet rays, said method comprising the
`steps of:
`
`(a) guiding and/or forcing fluent material through filter(s)
`to removelarge particles;
`
`(b) using circuitous sterilizing chamber(s) with round-
`about path(s), or spiral path(s), or sinuous path(s), or
`
`zigzag path(s), or other similar shapes of paths to
`contain said fluent material;
`
`live
`(c) employing intense UV irradiation to kill all
`microorganismsin said fluent material passing through
`said chamber(s);
`
`(d) converting ozone in air into oxygen whendealing with
`air;
`
`(e) dischargingsterilized fluent material out of said cham-
`ber(s).
`2. Apparatusfor sterilizing fluent material in large volume
`by radiation of ultraviolet rays, said apparatus comprising:
`
`(a) an inlet 1 guiding in fluent materialfor sterilizing;
`
`(b) a power unit 2 positioned in said inlet 1;
`
`(c) an inlet filter 3 connected with said inlet 1 to remove
`fairly large particles from said fluent material;
`
`(d) a circuitous sterilizing chamber 10 connected with
`said inlet filter unit 3;
`
`(e) a group of UV light tubes 15 positioned, along the flow
`direction, inside said chamber 10 providing high-den-
`sity ultraviolet radiation to irradiate passing said fluent
`material;
`
`(£) connected with said chamber 10,an outlet filter unit 13
`to removeanyparticles larger than the requirements of
`application;
`
`(g) a catalytic filter comprised in said outletfilter unit 3 to
`convert ozone into oxygen;
`
`(h) an inspection window or a sample faucet 12 for taking
`testing samples;
`
`(i) an outlet 11 extending from said outlet filter 13 to
`discharge sterilized fluent material.
`3. The apparatus of claim 2 wherein said circuitous
`sterilizing chamber 10 may form roundabout path(s), or
`spiral path(s), or sinuous path(s), or zigzag path(s), or other
`similar shapes of paths for the purpose of increasing UV
`exposure.
`4. The apparatus of claim 2 wherein said chamber 10 is
`constructed with smooth curved flow guiding interior 7 at
`every turning section to form flow low flow resistant cham-
`ber.
`
`5. The apparatus of claim 2 wherein said chamber 10 has
`polished internal reflecting mirror surfaces 9 to increase UV
`killing effect.
`6. The apparatus of claim 2 comprises UV visual inspec-
`tion window(s) 5 in every section of said chamber10.
`7. The apparatus of claim 2 further comprises UV sen-
`sor(s) 6 in every section of said chamber 10 as autofeedback
`mechanism.
`
`8. The apparatus of claim 2 further comprises an inspec-
`tion window or a sample faucet 12 on said outlet 11.
`9. The apparatus of claim 2 wherein ozone generation is
`suppressed by use of non-ozone germicidal lamps.
`10. The apparatus of claim 2 wherein an outletfilter umit
`13 includes a catalytic filter to convert ozone into oxygen
`when dealing with air.
`
`*
`
`*
`
`*
`
`*
`
`*
`
`10
`
`10
`
`