US20020054839A1

US20020054839A1 - Method and apparatus for efficient surface generation of pure O3

Info

Publication number: US20020054839A1
Application number: US10/034,084
Authority: US
Inventors: Yee Chen
Original assignee: Chen Laboratories
Current assignee: Chen Laboratories
Priority date: 1999-11-12
Filing date: 2001-12-28
Publication date: 2002-05-09
Also published as: US6372097B1

Abstract

A method and apparatus for generating a polyatomic form of a prescribed element is disclosed. The apparatus includes a chamber and a plasma source. The plasma source is coupled to the chamber for producing plasma of the prescribed element from a supply of the element in a gaseous state. The plasma includes at least a mixture of single atomic and double atomic species of the prescribed element. Lastly, a quencher is disposed within the chamber proximate an output of the plasma source for facilitating generation of the polyatomic form of the prescribed element from the mixture of single atomic and double atomic species of the prescribed element. In one embodiment, the element is oxygen and the polyatomic form is ozone.

Description

This application claims the benefits of the earlier filed provisional application Ser. No. 60/165,380 filed Nov. 12, 1999.[0001]

BACKGROUND

1. Field of the Invention

The present invention relates generally to a methodology of generating ozone, and more particularly, to a method and apparatus for efficient surface generation of high concentration ozone and liquid ozone.

2. Discussion of the Related Art

Prior to the embodiments of the present disclosure, generation of ozone (O ₃) with high concentration (e.g., on the order of greater than twenty-five percent (25%)) and high rate of pure O₃generation have not been possible. A majority of the known state-of-the-art O₃generation is accomplished through corona discharge, which has a yield on the order of around ten to fifteen percent (10-15%) maximum and at a low generation rate. Usage of O₃has typically been limited to a low concentration (e.g., less than fifteen percent (<15%) and the generating of O₃constrained to being generated at the point-of-use.

Another method of ozone generation is UV ozone generation, which has an even lower concentration yield as compared to electric discharge ozone generation. A third and less popular method is electrolytic ozone generation. With electrolytic ozone generation, aqueous solutions of sulfuric or perchloric acid are electrolyzed with extremely high anodic current densities. In the later instance, oxygen (O ₂) and, in the case of sulfuric acid solutions, peroxydisulfuric acid, H₂S₂O₈, are by-products.

Accordingly, a method and apparatus for the generation of high concentration O ₃at the point-of-use (or at other than the point-of-use), and at a substantially limitless scalable production rate and volume are desired.

SUMMARY

According to one embodiment, an apparatus for generating ozone (O ₃) includes a chamber and a plasma source. The plasma source couples to the chamber and produces oxygen plasma from a supply of oxygen. The plasma includes at least a mixture of O and O₂species. Lastly, a quencher is disposed within the chamber proximate an output of the plasma source for facilitating ozone generation from the mixture of O and O₂species.

A technical advantage provided by the embodiments of the present disclosure is the generation of high concentration O ₃at the point-of-use or location other than the point-of-use. In addition, the present embodiments provide the ability for achieving a substantially limitless scalable production rate and volume of high concentration O₃.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 illustrates a schematic view of an apparatus for surface generation of ozone according to an embodiment of the present disclosure; [0010]
FIG. 2 illustrates a schematic view of an apparatus for surface generation of ozone according to another embodiment of the present disclosure; [0011]
FIG. 3 illustrates a schematic view of an apparatus for surface generation of ozone according to another embodiment; [0012]
FIG. 4 illustrates a cross sectional view of a quencher of FIG. 3 in greater detail; [0013]
FIGS. 5A and 5B illustrate a top view and a cross section view of a portion of the quencher of FIG. 4; and [0014]
FIG. 6 illustrates a block diagram view of a system apparatus for processing media utilizing the method and apparatus for surface generation of ozone of the present disclosure.[0015]

DETAILED DESCRIPTION

With reference now to FIG. 1, an [0016] apparatus 10 for generating ozone (O₃) includes a chamber 12, such as a vacuum chamber or other suitable chamber. A plasma source 14 couples to the chamber 12 for producing oxygen plasma 16 from a supply of oxygen 18. The plasma 16 includes at least a mixture of O and O₂species. A quencher 20 is disposed within the chamber 12 proximate an output of the plasma source 14 for facilitating ozone generation from the mixture of O and O₂species. The plasma source 14 includes an R.F. plasma source, a microwave source, or other suitable plasma sources. Electrical power is supplied to plasma source 14 as indicated by reference numeral 22.
The [0017] quencher 20 includes a quenching surface located down-stream of the plasma source within a prescribed region 17 of the oxygen plasma 16, such as in the plasma plume. The oxygen plasma flows across the quenching surface to generate ozone. In one embodiment, the quenching surface includes a plurality of quenching surfaces. Still further, the plurality of quenching surfaces include a plurality of flow channels 24 having inputs 26 and outputs 28, the inputs 26 being disposed proximate the output of the plasma source 14.
[0018] System apparatus 10 further includes a controller 30. Controller 30 includes any suitable programmable controller or computer for use in controlling various process parameters of the present method and apparatus. Process parameters are selected according to a prescribed process parameter window for a given ozone generation application (or for generation of a poly-atomic molecular form of a prescribed element). Controller 30 is programmed for performing desired functions as discussed herein. Programming may be accomplished using techniques well known in the art, thus not discussed further herein.
[0019] Controller 30 provides appropriate control signals for supply gas control 32, temperature control 34, plasma control 36, and vacuum pump control 38. Vacuum pump 40 provides a desired vacuum within chamber 12, as may be required for a given application. Controller 30 provides additional control signals, as may be needed, for control of additional parameters of a prescribed process window.
The [0020] apparatus 10 for generating ozone further includes means for controlling a temperature of the quencher in a prescribed manner for producing a desired form of liquid-phase or gas-phase ozone. Temperature control includes providing a thermal channel 42 in communication with the quencher 20 suitable for passage of a prescribed coolant through the thermal channel. The temperature control further includes controlling a flow rate of coolant through the thermal channel, such as, with a controllable flow valve or regulator (not shown). Controller 30 provides a temperature control signal 34, which may be used for controlling the flow valve or regulator, as appropriate. The coolant may include liquid nitrogen, liquid helium, liquid oxygen, or other suitable coolant.
As shown in FIG. 1, an enlarged [0021] view 50 of a portion of a flow channel 24 is shown. The enlarged view 50 illustrates several layers of adsorbed O₂on the quencher surface 52 of a flow channel 24. The layers of adsorbed O₂are characterized by an inner layer 54, intermediate layer (or layers) 56, and an outer layer 58, as discussed further herein below. Briefly, O from the mixture of O₂and O collide with the O₂from an outer layer 58 to produce O₃. Depending upon the process parameters, O₃in the liquid phase 60 migrates to the quencher surface 52 (or O₃in the gas phase 62 flows within channel 24) to the output 28 of the respective flow channel 24.
With respect to a method for generating ozone (O[0022] ₃), the method includes providing a chamber, such as a vacuum chamber or other suitable chamber. The method further includes providing a plasma source coupled to the chamber for producing oxygen plasma from a supply of oxygen. The plasma includes at least a mixture of O and O₂species. Lastly, a quencher is disposed within the chamber proximate an output of the plasma source for facilitating ozone generation from the mixture of O and O₂species. The plasma source includes an R.F. plasma source, a microwave source, or other suitable source.
Providing the quencher includes providing a quenching surface located down-stream of the plasma source within a prescribed region of the oxygen plasma, wherein the oxygen plasma flows across the quenching surface to generate ozone. In one embodiment, the quenching surface includes a plurality of quenching surfaces. The plurality of quenching surfaces include a plurality of flow channels having inputs and outputs, the inputs disposed proximate the output of the plasma source. [0023]
The method further includes controlling a temperature of the quencher in a prescribed manner for producing a desired form of liquid-phase or gas-phase ozone. Controlling the temperature of the quencher includes providing a thermal channel in communication with the quencher suitable for passage of a prescribed coolant through the thermal channel. Controlling the temperature further includes controlling a flow rate of coolant through the thermal channel. In one embodiment, the coolant includes liquid nitrogen, liquid helium, liquid oxygen, or other suitable coolant. [0024]
According to another embodiment, a method of generating ozone (O[0025] ₃) includes supplying oxygen to a plasma source; igniting and producing an oxygen plasma with the plasma source, and directing the oxygen plasma for movement over a quenching surface of a quencher. The oxygen plasma contains a mixture of O and O₂. The quenching surface is positioned down-stream of the plasma source within a prescribed region of the oxygen plasma. The oxygen plasma flows across the quenching surface to facilitate ozone generation from the mixture of O and O₂. The quenching surface includes a plurality of flow channels disposed within the quencher, the flow channels having inputs and outputs. The flow channel inputs are arranged proximate an output of the plasma source.
The method further includes controlling a temperature of the quenching surface in a prescribed manner for producing a desired form of liquid-phase or gas-phase ozone. In addition, the temperature of the quenching surface may also be regulated. Regulating the temperature includes controlling the flow rate of a coolant flowing through a cooling channel disposed in the quencher. The coolant may include liquid nitrogen, liquid helium, liquid oxygen, or other suitable coolant. [0026]
The present embodiments further include an apparatus for generating a polyatomic form of a prescribed element. The apparatus includes a chamber, a plasma source coupled to the chamber, and a quencher. The plasma source produces plasma of the prescribed element from a supply of the element in a gaseous state. Accordingly, the plasma includes at least a mixture of single atomic, double atomic and polyatomic species of the prescribed element. The quencher is disposed within the chamber proximate an output of the plasma source. [0027]
The quencher facilitates generation of the polyatomic form of the prescribed element from the mixture of single atomic, double atomic and polyatomic species of the prescribed element. Similar to the other embodiments the plasma source includes an R.F. plasma source, a microwave source, or other suitable plasma source. The quencher includes a quenching surface located down-stream of the plasma source within a prescribed region of the plasma. The plasma flows across the quenching surface to generate the polyatomic form of the prescribed element. The quenching surface includes a plurality of quenching surfaces, further including a plurality of flow channels having inputs and outputs. The flow channel inputs are disposed proximate an output of the plasma source. [0028]
The embodiment further includes a means for controlling a temperature of the quencher in a prescribed manner for producing a desired liquid-phase or gas-phase polyatomic form of the prescribed element. The temperature control means includes a thermal channel in communication with the quencher suitable for passage of a prescribed coolant through the thermal channel. The temperature control means further includes means for controlling a flow rate of coolant through the thermal channel. The coolant includes liquid nitrogen, liquid helium, liquid oxygen, or other suitable coolant. The prescribed element can include oxygen and the polyatomic form of the prescribed element includes ozone (O[0029] ₃).
The embodiments of the present disclosure advantageously enable the generation of high concentration ozone (O[0030] ₃), on the order of greater than fifty percent (>50%) and at a substantially limitless scalable production rate and volume. The present embodiments enable the production of liquid O₃at a substantially limitless scalable production rate and volume, for example, by a chemical plant. Having a scalable production rate and volume enables the usage of pure O₃without the limitation of point-of-use O₃generation. Accordingly, liquid O₃can be transported, for example, in a suitable 161° K. refrigerated container or vessel.
A principal feature of the present embodiments is the surface O[0031] ₃generation through quenching of an oxygen (O₂) plasma. Oxygen (O₂) gas of reasonable purity, or of a prescribed concentration level, is fed into a discharge vessel Of O₂plasma. In one embodiment, the purity of the O₂gas is on the order of between 99% to 99.999%. It is noted that other purities of O₂gas can be used, however, the purity of the supply will influence the purity of generated ozone.
The O[0032] ₂plasma produces a substantially controllable ratio of O and O₂mixture. With the oxygen plasma alone, O₃can be formed through a three-body collision in the gas-phase. This three-body collision can be expressed as O+O₂+h/λ→O₃, where h is the Planck's constant (6.63×10⁻³⁴joules-second, λ is the wavelength of vibration, and h/λ represents a phonon (i.e., a quantum of vibrational energy). The expression O+O₂+h/λ→O₃maintains the laws of conservation of momentum and the conservation of energy. The third body h/λ is involved since the physical laws state that simultaneous conservation of both momentum and energy in a two-body only collision is impossible.
The probability of a three-body collision in the gas phase, however, is extremely low. In addition, the plasma is generally very hot. The very hot plasma exponentially accelerates the decomposition of any O[0033] ₃, that may have formed. Accordingly, using O₂plasma alone, the O₃concentration resulting therefrom is extremely low.
The embodiments of the present disclosure employ a method of surface generation of O[0034] ₃. On a prescribed surface, the reaction of gas molecules O+O₂→O₃proceeds as a two-body process. The two-body process has a much higher probability than the three-body collision in the gas-phase using the plasma alone. The prescribed surface acts as the supplier of surface phonon.
The probability of two bodies of certain momentum colliding with each other directly on a surface, where the surface acts as a limitless supplier of phonon, is higher than that of three bodies colliding in space. However, the two-body process alone is not extremely efficient in generating high concentration O[0035] ₃. Accordingly, the surface generation method of the present disclosure carries the two-body process one step further. That is, one body, namely O, collides with a “phonon and O₂supply” surface to generate the desired output, O₃.
To carry out the surface generation method of the present disclosure, the plasma is made to flow across a prescribed surface area that is maintained at a temperature lower than that of the plasma. The prescribed surface area is of sufficient size and area to increase the probability of the plasma engaging the surface. Accordingly, the surface area is sufficient to guarantee that particles hit the surface (i.e., a large surface area with respect to the particle size). [0036]
The combination of surface area and surface temperature facilitate a process wherein O[0037] ₂from the plasma adsorbs (either physisorbs and/or chemisorbs) on the surface. The adsorbed O₂creates at least one thin layer, up to several or more molecular layers, of O₂. Adsorption is defined as the adhesion in an extremely thin layer of molecules (as of gases, solutes, or liquids) to the surface of solid bodies or liquids with which they are in contact. Accordingly, the adsorbed O₂on the cold surface forms an O₂and phonon supply surface. The O from the plasma collides with the adsorbed O₂, whereby O₃is immediately formed, generally upon one collision.
The type of collision characterized by O from the plasma colliding with adsorbed O[0038] ₂can be viewed as a single-body colliding with a relatively large surface with limitless supply of phonon. The probability of such collision is close to one (i.e. almost a certainty). The temperature of the generation surface and that of the space near the generation surface is maintained sufficiently low (in comparison to the plasma temperature), such that the formed O₃remains stable.
Referring again to FIG. 1, as O collides with the O[0039] ₂on an outer layer 58 of the adsorbed O₂, O₃is formed. Upon the formation of O₃, additional adsorbed O₂migrates and/or bubbles up from an inner layer 54 (or intermediate layer 56) to the outer layer 58, such that the process of O₃formation continues. In other words, the layers (or layer) of adsorbed O₂beneath the outer layer supply additional O₂for subsequent O₃generation. In addition, upon generation, the O₃flows in a direction away from the plasma, either in gas-phase or liquid-phase. In an alternate embodiment, an inert gas is added to the O₂supply gas to assist in transporting formed O₃away from and/or off of the O₃generation surface.
The prescribed surface for use in O[0040] ₃generation is referred to herein as a quencher. The quencher is characterized by a structure of cold surfaces relative to the plasma temperature. The quencher is generally placed proximate an output boundary of the plasma. More particularly, the quencher is placed in the path of the plasma plume proximate the output boundary of the plasma.
The concentration ratio of O and O[0041] ₂is controllable, for example, by the feed gas O₂flow rate, ambient pressure, and power input to the plasma, etc. The temperature of the quencher surface is also controllable. For example, the temperature can be controlled by one or more suitable means, such as, the type of coolant used and the coolant flow rate through coolant channels within the quencher. The type of adsorption (whether physisorption or chemisorption) is controllable, for example, by the type of surface material and/or surface chemical of the quencher. Plasma flow and the corresponding flow pattern for facilitating ozone generation are controllable, for example, by a combination of the shape of the quencher, the characteristic bends and shapes of the flow channels, and the quencher flow channel surface shape(s). The overall shape of the quencher and the quencher's surface shape can be configured by varying or changing the physical design of the quencher as may be required for a particular implementation.
To obtain a maximum concentration of generated O[0042] ₃(on the order of approximately 100%), a prescribed range of the process window parameters can be assembled and/or established. That is, a parameter window of process and hardware can be established within which i) all O₂from the plasma that enter into the space of the quencher are adsorbed on the quencher surface and ii) wherein there is a sufficient amount of O, the O interacting with surface O₂, such that substantially all the O and surface O₂in the quencher are consumed, becoming O₃. In addition, as discussed herein, the quencher surfaces are cold relative to the plasma temperature and therefore species inside the quencher space, such as gas-phase O, O₂, and O₃, are significantly colder than that in the plasma by an approximate order of magnitude lower.
For example, in one embodiment, the temperature of the gas-phase plasma is approximately 800° K. The temperature of the quencher surface is approximately 100° K, and the temperature within the quencher space is approximately 200° K. [0043]
As mentioned herein above, gas-phase three-body generation of stable O[0044] ₃is still possible, although low in probability. A majority of O₃is generated on the quencher surface. In addition to the above discussion, another important effect of the coldness of the quencher (including the surface and the space thereof) is to allow the existence of stable O₃after its generation without suffering O₃decomposition.
FIG. 2 illustrates another [0045] embodiment 100 of the method and apparatus of the present disclosure. A plasma source 14 is mounted on a chamber 12, the chamber for housing the quencher 20 and the resulting O₃. The plasma source 14 includes a plasma tube 64. Plasma source 14 receives a supply of oxygen gas at inlet 66. Electrical power is supplied at 68. In this embodiment, it is desirable to avoid having plasma actively discharged into the space of the quencher 20 and in the region down-stream from the quencher, so as to eliminate unnecessary heating of the quencher by the plasma. However, this does not exclude having the plasma in the chamber that houses the quencher where, in a particular situation, extra heating of the quencher by the extra plasma is not a concern. Flow direction is indicated by arrow 70.
The [0046] plasma source 14 can include any type plasma heated by a suitable method, such as inductive heating, capacitive heating, DC heating or wave heating (e.g., ECR, Helicon, etc.). The quencher 20 is generally positioned proximate the output end of the plasma source. In one embodiment, the quencher 20 substantially occupies an entire area of the plasma output boundary for the purpose of achieving a higher efficiency.
The [0047] quencher 20 provides a large surface area (relative to the size of a particle), over which the species from the plasma (e.g., O, O₂) can flow across (or flow-by). The geometry of the quencher's flow-path (i.e., its surface 52) and the type of the flow condition are selected in a prescribed manner to allow sufficient interaction between the flow species (e.g., O, O₂, etc.) and the quencher's surfaces. The quencher's flow path and flow condition facilitate adsorption of O₂on the cold quencher surfaces and collision of O with the adsorbed O₂, thereby leading to the surface generation of O₃. A suitable process control, such as provided via controller 30 of FIG. 1, adjusts the quencher surface temperature as required for a particular implementation.
It should be noted that the general methodology of surface O[0048] ₃generation from an O₂plasma is not limited to physisorption. The flow-by O₂or O can be placed on the surface through chemisorption, provided that an appropriate surface material is used. The main point is that the surface can always act as the source of phonon to supply the necessary momentum for the reaction of O+O₂→O₃. However, note that the particular reaction is not limited to the above reaction alone. There are other potential reaction channels through which O₃can be generated on the quencher surface.
In connection with the present embodiments, the boiling point for O[0049] ₃is approximately 161° K, the boiling point for O₂is 90° K, and the boiling point for N₂is 77° K. In the case of generating high concentration or pure O₃(gas phase), the quencher surface does not need to be as cold as the liquid-point at which the generated O₃liquefies on the quencher surface under the chamber's particular pressure/temperature conditions. According to the present embodiments, as long as the flow-by O₂can sufficiently physisorb on the quencher surface for a given duration of time such that the flow-by O can interact with the adsorbed O₂for the generation of O₃, the method of surface O₃generation is satisfied.
In one embodiment, the newly generated O[0050] ₃can be physisorbed on the quencher surface. The physisorbed O₃subsequently migrates down-stream away from the plasma and into the chamber for collection in a suitable collection vessel 72 and/or routing via suitable piping 74, as appropriate. In another embodiment, the newly generated O₃may have gained enough thermal energy from the flow-by species that the newly generated O₃itself is desorbed from the quencher surface and transported down-stream into the chamber for collection and/or routing, as appropriate. The coldness of the quencher surface cools down the gas-phase temperature, reducing and/or totally eliminating the probability of the decomposition of the generated/transported O₃.
In yet another embodiment, using a prescribed process window of chamber pressure and temperature conditions, generating pure O[0051] ₃is accomplished with the quencher surface at a temperature satisfying the liquid-point of the generated O₃(i.e., lower than the previous example). For example, the quencher surface temperature can be selected such that, under the chamber's pressure and temperature conditions, the flow-by O₂physisorb on the quencher surface (but the surface temperature need not be so low as to have the adsorbed O₂accumulate into liquid O₂) for the surface O₃generation process. This is followed by the liquefaction of the generated O₃on the quencher surface. Under the appropriate chamber pressure and temperature condition, the quencher surface's liquid O₃poses a vapor pressure that contributes to the output of the pure O₃. In addition, the plasma and the flow parameters can be adjusted as needed so that the substantial majority or entire flow-by O₂are consumed for the production of high concentration or pure O₃gas.
In the embodiments for producing liquid O[0052] ₃, a suitable collection vessel provides for storage of the liquefied O₃. For example, storage can be provided using any suitable liquid storage container known in the art.
FIG. 3 illustrates another [0053] embodiment 110 of the method and apparatus for generation of O₃according to the present disclosure. The plasma source 14 includes an inductive plasma. In this embodiment, the heated plasma volume is approximately 1.25″ diameter X 3.5″ long. The pure O₂feed rate is typically centered at approximately one to two standard liters per minute (1-2 slm). The chamber 12 includes a stainless steel chamber such as that used within a typical laboratory environment. The chamber includes a volume on the order of approximately 16″ diameter X 23″ long.
FIG. 4 illustrates a cross-section view of the exemplary quencher of FIG. 3 in greater detail. According to one embodiment, the quencher is characterized by a “flow channels” design. The [0054] flow channels 24 portion of the quencher assembly includes copper (Cu), for thermal considerations, with nickel (Ni) plating, for chemical protection. FIGS. 5A and 5B show a top view and a cross sectional view of one of the Cu/Ni members or pieces of the quencher 20, particularly illustrating the flow channels 24 in greater detail. In one embodiment, the quencher includes three Cu/Ni members or pieces that are silver-soldered together. Note that while this embodiment illustrates straight flow channels 24, it should be noted that the flow channels could also include prescribed bends and/or shapes to further increase an interaction between the flow species and the quencher's surfaces, as may be needed for a particular design implementation.
Referring to FIGS. [0055] 3-5, the quencher assembly is mounted proximate the output end of the plasma source using suitable fasteners 80. For example, thermal isolators or ceramic posts may be used. An input end 26 of the quencher 20 (i.e., a top surface thereof) is proximate to and borders a plasma body of a plasma to be produced by the plasma source 14. In one embodiment, the input end 26 of the quencher is disposed approximately 3 mm from an end of the plasma tube (or plasma body) of the plasma source 14. Suitable thermal insulation is provided between the quencher and the chamber wall area, for example, via an ambient vacuum gap.
In operation, according to one embodiment, the [0056] system 110 is first drawn into a vacuum of approximately 5 mtorr (5×10³torr). Subsequent to achieving an initial vacuum, liquid nitrogen (LN₂) cooling is introduced. That is, LN₂circulates through cooling channels 42 at a prescribed flow rate to cool the quencher 20 to a temperature of approximately 80° K, wherein the surface of the quencher being approximately 110° K. This step is followed by the introduction of flow of O₂and ignition of the plasma. In response to ignition of the plasma, the process of surface generation of O₃begins. In one embodiment, the R.F. power for the plasma source is on the order of 1200 W, and the pressure in the plasma region of the plasma source is approximately on the order of 2 to 3 torr.
Accumulation of liquid O[0057] ₃on the quencher surfaces starts to occur almost immediately following the ignition of the plasma. As liquid O₃accumulates thicker within the quencher, the liquid O₃surface is subject to boil (i.e., via vaporization into the chamber) due to both the thermal isolation by the liquid O₃itself from the quencher surface and the action of the flow-by species. At the entrance of the quencher assembly, the flow-by species are largely O/O₂mixture. Towards the end of the quencher assembly, the flow-by species becomes largely O₃(i.e., the desorbed O₃or vaporized O₃). For example, with a proper adjustment of the initial O/O₂mixture from the plasma and the total flow rate, a substantially complete depletion of O₂can be accomplished at the exit of the quencher assembly. Accordingly, the desorbed O₃accumulates in and/or fills a down-stream area of the chamber. The O₃in the chamber can then be drawn out by the vacuum pump. In addition, the O₃can be stored in a suitable container, routed, and/or delivered to a prescribed oxidation application.
The examples presented herein are illustrative only and not intended to restrict the present embodiments. The present embodiments include a methodology for manufacture of pure O[0058] ₃, high concentration O₃, and liquid O₃. Other suitable apparatus can be assembled for carrying out the methodology of surface O₃generation through the quenching of O₂plasma.
The initial adsorption of the flow-by species (O/O[0059] ₂) can be accomplished through either physisorption (in this case, the physisorption of O₂on a cold surface), or chemisorption by a surface of the adequate material (in this case, the chemisorption of O or O₂). Also, the surface uptake of flow-by species could be a combination of physisorption and chemisorption. For example, in the above discussed implementation of FIG. 4, it is possible, although believed low in occurrence, that some flow-by O gets weakly chemisorbed on the quencher surface and surface O₃is subsequently formed by a flow-by O₂or other flow-by single molecule oxygen (O). It is important to significantly lower the gas-phase species temperature as the species flow through the “surface apparatus,” to a point that is much lower than that of the plasma so that the probability of O₃decomposition is drastically reduced.
Apparatus or hardware for collection of liquid O[0060] ₃includes any suitable existing technology, which can be applied for use in the collection and storage of liquid O₃. For gas O₃, the liquid O₃on the surfaces of the quencher assembly is allowed to vaporize and expand. The vaporized O₃is then pumped out for storage and/or delivery to the particular oxidation application.
While the present embodiments include a method and apparatus for producing pure O[0061] ₃, the method and apparatus for producing pure O₃further include applications requiring high concentration O₃, pure O₃, and liquid O₃. As a point-of-use O₃source, the present embodiments can be applied for sterilization, cleaning, deodorizing and general oxidation. Liquid O₃can also be stored and transported to a use location, other than the O₃production location, to be dispensed for use in similar applications. For example, liquid O₃can be used as an oxidizer of the rocket fuel in a rocket, thereby significantly reducing the volume and mass of the rocket at launch.
Turning now to FIG. 6, the present embodiments further include a [0062] system 120 for processing media 121 with ozone (O₃). The media processing system 120 includes at least one processing vessel 122; suitable means 124 for disposing media to be processed into the at least one processing vessel; and means 126 for removing the processed media from said at least one processing vessel.
In addition, the media processing system includes means [0063] 128 for supplying ozone to the at least one processing vessel 122 to facilitate a processing of the media 121 by the ozone. The ozone supplying means 128 is similar to that discussed herein with respect to FIGS. 1-3. The ozone supplying means includes a chamber, a plasma source coupled to the chamber, and a quencher disposed with the chamber proximate an output of the plasma source. The plasma source produces an oxygen plasma from a supply of oxygen, the plasma including at least a mixture of O and O₂species. The quencher facilitates ozone generation from the mixture of O and O₂species.
The processing system may also include a [0064] means 130 for destroying residual ozone subsequent to a processing of the media. The residual ozone destructor 130 includes any suitable means known in the art for reducing the level of residual ozone to a prescribed safe level. The residual ozone destructor 130 is used in conjunction with removal of the media from the processing chamber, further in preparation for discharge, for example, into atmosphere.
The present embodiments further include a method for processing media with ozone (O[0065] ₃). The method includes providing at least one processing vessel, disposing the media to be processed into the at least one processing vessel, supplying ozone to the at least one processing vessel to facilitate a processing of the media by the ozone, and removing the processed media from the at least one processing vessel subsequent to processing of the media by the ozone. In addition, the method includes destroying residual ozone subsequent to ozone processing of the media.
For the method of processing media, a prescribed ozone generator supplies the ozone. The ozone generator includes a generator as discussed herein with respect to FIGS. [0066] 1-3. The ozone generator includes a chamber, a plasma source coupled to the chamber for producing oxygen plasma from a supply of oxygen, and a quencher disposed within the chamber proximate an output of the plasma source. The plasma includes at least a mixture of O and O₂species. The quencher facilitates ozone generation from the mixture of O and O₂species.
In one embodiment, the at least one [0067] processing vessel 122 of the media processing system and method 120 includes a processing chamber. The processing chamber is characterized by an input and an output. The means 124 for disposing media into the processing chamber couples to the input of the processing chamber. The means 126 for removing the processed media from the processing chamber couples to the output of the processing chamber. In one embodiment, the processing chamber input and output represent a single portal.
In another embodiment, the media processing system and [0068] method 120 are utilized in the manufacture of semiconductor devices. In this instance, the at least one processing vessel 122 includes a semiconductor substrate processing chamber and the media includes a semiconductor substrate.
In another embodiment, the media processing system and [0069] method 120 are utilized for bioremediation of a gas, liquid, or solid media. In this instance, the at least one processing vessel 122 includes a bioremediation processing chamber and the media includes one of the following selected from the group consisting of gaseous media, liquid media, and solid media.
While the invention has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention, as set forth in the following claims. [0070]

Claims

What is claimed is:

1. An apparatus for generating ozone (O₃) comprising:

a chamber;

a plasma source coupled to said chamber for producing an oxygen plasma from a supply of oxygen, the plasma including at least a mixture of O and O₂species; and

a quencher disposed within said chamber proximate an output of said plasma source for facilitating ozone generation from the mixture of O and O₂species.

2. The apparatus of claim 1, wherein said plasma source includes one of the following selected from the group consisting of an r.f. plasma source and a microwave source.

3. The apparatus of claim 1, wherein said quencher includes a quenching surface located down-stream of said plasma source within a prescribed region of the oxygen plasma, wherein the oxygen plasma flows across the quenching surface to generate ozone.

4. The apparatus of claim 3, further wherein the quenching surface includes a plurality of quenching surfaces.

5. The apparatus of claim 4, still further wherein the plurality of quenching surfaces include a plurality of flow channels having inputs and outputs, the inputs disposed proximate the output of said plasma source.

6. The apparatus of claim 1, further comprising:

means for controlling a temperature of said quencher in a prescribed manner for producing a desired form of liquid-phase or gas-phase ozone.

7. The apparatus of claim 6, wherein said temperature control means includes a thermal channel in communication with said quencher suitable for passage of a prescribed coolant through the thermal channel.

8. The apparatus of claim 7, wherein said temperature control means further includes means for controlling a flow rate of coolant through the thermal channel.

9. The apparatus of claim 7, wherein the coolant includes one of the following selected from the group consisting of liquid nitrogen, liquid helium, and liquid oxygen.

10. An apparatus for generating ozone (O₃) comprising:

a chamber;

a plasma source coupled to said chamber for producing an oxygen plasma from a supply of oxygen, the plasma including at least a mixture of O and O₂species;

a quencher disposed within said chamber proximate an output of said plasma source for facilitating ozone generation from the mixture of O and O₂species, wherein said quencher includes a plurality of quenching surfaces located down-stream of said plasma source within a prescribed region of the oxygen plasma, the plurality of quenching surfaces including flow channels having inputs and outputs, the inputs disposed proximate the output of said plasma source, wherein the oxygen plasma flows across the quenching surfaces to generate ozone; and

means for controlling a temperature of said quencher in a prescribed manner for producing a desired form of liquid-phase or gas-phase ozone, said control means including at least one channel in thermal communication with said quencher suitable for passage of a prescribed coolant through the channel, said control means further including a controllable flow valve for controlling a flow rate of coolant through the channel.

11. A method for generating ozone (O₃) comprising:

providing a chamber;

providing a plasma source coupled to the chamber for producing an oxygen plasma from a supply of oxygen, the plasma including at least a mixture of O and O₂species; and

disposing a quencher within the chamber proximate an output of the plasma source for facilitating ozone generation from the mixture of O and O₂species.

12. The method of claim 11, wherein providing the plasma source includes providing one of the following selected from the group consisting of an r.f. plasma source and a microwave source.

13. The method of claim 11, wherein providing the quencher includes providing a quenching surface located down-stream of the plasma source within a prescribed region of the oxygen plasma, wherein the oxygen plasma flows across the quenching surface to generate ozone.

14. The method of claim 13, wherein the quenching surface includes a plurality of quenching surfaces.

15. The method of claim 14, further wherein the plurality of quenching surfaces include a plurality of flow channels having inputs and outputs, the inputs disposed proximate the output of the plasma source.

16. The method of claim 11, further comprising:

controlling a temperature of the quencher in a prescribed manner for producing a desired form of liquid-phase or gas-phase ozone.

17. The method of claim 16, wherein controlling the temperature of the quencher includes providing a thermal channel in communication with the quencher suitable for passage of a prescribed coolant through the thermal channel.

18. The method of claim 17, wherein controlling the temperature further includes controlling a flow rate of coolant through the thermal channel.

19. The method of claim 17, wherein the coolant includes one of the following selected from the group consisting of liquid nitrogen, liquid helium, and liquid oxygen.

20. A method for generating ozone (O₃) comprising:

providing a chamber;

providing a plasma source coupled to the chamber for producing an oxygen plasma from a supply of oxygen, the plasma including at least a mixture of O and O₂species;

disposing a quencher within the chamber proximate an output of the plasma source for facilitating ozone generation from the mixture of O and O₂species, wherein the quencher includes a plurality of quenching surfaces located down-stream of the plasma source within a prescribed region of the oxygen plasma, the plurality of quenching surfaces including flow channels having inputs and outputs, the inputs disposed proximate the output of the plasma source, wherein the oxygen plasma flows across the quenching surfaces to generate ozone; and

controlling a temperature of the quencher in a prescribed manner for producing a desired form of liquid-phase or gas-phase ozone, wherein controlling the temperature includes providing at least one channel in thermal communication with the quencher suitable for passage of a prescribed coolant through the channel and providing a controllable flow valve for controlling a flow rate of coolant through the channel.

21. A method of generating ozone (O₃) comprising:

supplying oxygen to a plasma source;

igniting and producing an oxygen plasma with the plasma source, the oxygen plasma including a mixture of O and O₂; and

directing the oxygen plasma for movement over a quenching surface of a quencher, the quenching surface located down-stream of the plasma source within a prescribed region of the oxygen plasma, wherein the oxygen plasma flows across the quenching surface to facilitate ozone generation from the mixture of O and O₂.

22. The method of claim 21, further comprising:

controlling a temperature of the quenching surface in a prescribed manner for producing a desired form of liquid-phase or gas-phase ozone.

23. The method of claim 21, wherein the quenching surface includes a plurality of flow channels disposed within the quencher, the flow channels having inputs and outputs, the inputs arranged proximate an output of the plasma source.

24. The method of claim 23, further comprising:

regulating a temperature of the quenching surface.

25. The method of claim 24, wherein regulating the temperature includes controlling the flow rate of a coolant flowing through a cooling channel disposed in the quencher.

26. The method of claim 25, wherein the coolant includes one of the following selected from the group consisting of liquid nitrogen, liquid helium, and liquid oxygen.

27. An apparatus for generating a polyatomic form of a prescribed element comprising:

a chamber;

a plasma source coupled to said chamber for producing plasma of the prescribed element from a supply of the element in a gaseous state, the plasma including at least a mixture of single atomic and double atomic species of the prescribed element; and

a quencher disposed within said chamber proximate an output of said plasma source for facilitating generation of the polyatomic form of the prescribed element from the mixture of single atomic and double atomic species of the prescribed element.

28. The apparatus of claim 27, wherein said plasma source includes one of the following selected from the group consisting of an r.f. plasma source and a microwave source.

29. The apparatus of claim 27, wherein said quencher includes a quenching surface located down-stream of said plasma source within a prescribed region of the plasma, wherein the plasma flows across the quenching surface to generate the polyatomic form of the prescribed element.

30. The apparatus of claim 29, further wherein the quenching surface includes a plurality of quenching surfaces.

31. The apparatus of claim 30, still further wherein the plurality of quenching surfaces include a plurality of flow channels having inputs and outputs, the inputs disposed proximate the output of said plasma source.

32. The apparatus of claim 27, further comprising:

means for controlling a temperature of said quencher in a prescribed manner for producing a desired liquid-phase or gas-phase polyatomic form of the prescribed element.

33. The apparatus of claim 32, wherein said temperature control means includes a thermal channel in communication with said quencher suitable for passage of a prescribed coolant through the thermal channel.

34. The apparatus of claim 33, wherein said temperature control means further includes means for controlling a flow rate of coolant through the thermal channel.

35. The apparatus of claim 33, wherein the coolant includes one of the following selected from the group consisting of liquid nitrogen, liquid helium, and liquid oxygen.

36. The apparatus of claim 27, wherein the prescribed element includes oxygen and the polyatomic form of the prescribed element includes ozone (O₃).

37. A system for processing media with ozone (O₃) comprising:

at least one processing vessel;

means for disposing media to be processed into said at least one processing vessel;

means for supplying ozone to said at least one processing vessel to facilitate a processing of the media by the ozone, said ozone supplying means including a chamber, a plasma source coupled to the chamber for producing an oxygen plasma from a supply of oxygen, the plasma including at least a mixture of O and O₂species, and a quencher disposed within the chamber proximate an output of the plasma source for facilitating ozone generation from the mixture of O and O₂species; and

means for removing the processed media from said at least one processing vessel.

38. The system of claim 37, further comprising:

means for destroying residual ozone subsequent to a processing of the media.

39. The system of claim 37, wherein said at least one processing vessel includes a processing chamber, the processing chamber having an input and an output, wherein said means for disposing media into the processing chamber is coupled to the input of the processing chamber, and said means for removing the processed media from the processing chamber is coupled to the output of the processing chamber.

40. The system of claim 37, wherein said at least one processing vessel includes a semiconductor substrate processing chamber and the media includes a semiconductor substrate.

41. The system of claim 37, wherein said at least one processing vessel includes a bioremediation processing chamber and the media includes one of the following selected from the group consisting of gaseous media, liquid media, and solid media.

42. A method for processing media with ozone (O₃) comprising:

providing at least one processing vessel;

disposing media to be processed into the at least one processing vessel;

supplying ozone to the at least one processing vessel to facilitate a processing of the media by the ozone, wherein supplying ozone is provided by an ozone generator including a chamber, a plasma source coupled to the chamber for producing an oxygen plasma from a supply of oxygen, the plasma including at least a mixture of 0 and O₂species, and a quencher disposed within the chamber proximate an output of the plasma source for facilitating ozone generation from the mixture of O and O₂species; and

removing the processed media from the at least one processing vessel subsequent to processing of the media by the ozone.

43. The method of claim 42, further comprising:

destroying residual ozone subsequent to ozone processing of the media.

44. The method of claim 42, wherein the at least one processing vessel includes a processing chamber, the processing chamber having an input and an output, wherein said disposing the media into the processing chamber is coupled through the input of the processing chamber and said removing the processed media from the processing chamber is coupled through the output of the processing chamber.

45. The method of claim 42, wherein the at least one processing vessel includes a semiconductor substrate processing chamber and the media includes a semiconductor substrate.

46. The method of claim 42, wherein the at least one processing vessel includes a bioremediation processing chamber and the media includes one of the following selected from the group consisting of a gaseous media and a porous solid media.