PHOTOCATALYTIC REACTOR STATOR AND METHOD OF USE

Abstract

An improved photocatalytic reactor stator having a first surface and an opposing second surface, and at least one channel extending between the first surface and the second surface to allow fluid flow through the stator. The at least one channel may be configured to redirect the fluid flow in a direction substantially parallel to the first and/or second surface. This improved photocatalytic reactor stator improves the performance of a photocatalytic reactor by increasing the mobility of the photocatalyst and thereby increasing the surface area of the catalyst that is exposed to the reactant and the UV light source.

Claims

1. A photocatalytic reactor stator, the stator comprising: a first surface and an opposing second surface, and at least one channel extending between the first surface and the second surface to allow fluid flow through the stator, wherein the at least one channel has a profile shaped to redirect the fluid flow in a direction substantially parallel to the first and/or second surface.

2. (canceled)

3. The stator as claimed in claim 1 wherein the at least one channel has at least a partially curved shaped profile, an inverted L-shaped profile, an inverted J-shaped profile, or an S-shaped profile.

4-5. (canceled)

6. The stator as claimed in claim 1 wherein the stator comprises a plurality of channels wherein an area between one channel and a neighbouring channel defines a section or sector of the stator surface and wherein the redirected fluid flow is configured to move, lift and/or roll fluidised photocatalyst particles from one section or sector to a neighbouring section or sector in a sequential manner.

7-9. (canceled)

10. The stator as claimed in claim 52 wherein the hood is located at or around a channel outlet and extends from the first or second surface.

11. (canceled)

12. The stator as claimed in claim 1 wherein the first and/or second surfaces comprise a plurality of hood structures and the area between one hood and a neighbouring hood defines a section or sector of the stator surface.

13. The stator as claimed in claim 12 wherein an outer surface of the hood is configured to be substantially streamlined whereby fluidised photocatalyst particles flow across the outer surface of the hood and into the neighbouring section or sector.

14. The stator as claimed in claim 13 wherein the hood is configured to move, lift and/or roll the photocatalyst particles as the fluidised photocatalyst particles flow across the outer surface of the hood.

15. The stator as claimed in claim 1 wherein the at least one channel has an inlet on the first surface and an outlet on the second surface, and wherein the channel inlet forms a groove or slot on or across the first surface and the channel outlet forms a groove or slot on or across the second surface.

16-18. (canceled)

19. The stator as claimed in claim 1, wherein the at least one channel has an inlet on the first surface and an outlet on the second surface, and wherein the channel outlet has a cross-sectional area which is equal to or less than the cross-sectional area of the channel inlet.

20. The stator as claimed in claim 1, comprising a plurality of channels, wherein the plurality of channel outlets are arranged to induce non-continuous sequential movement of photocatalyst particles.

21-25. (canceled)

26. The stator as claimed in claim 1 wherein the stator comprises a substantially circular disc.

27. The stator as claimed in claim 1 wherein the at least one channel is configured to introduce a circular, rotational or helical flow component to the fluid.

28. The stator as claimed in claim 1 wherein the stator is configured to create a vortex in the fluid flow.

29. The stator as claimed in claim 1 wherein the stator comprises a minimum of two channels and a maximum of one hundred channels, and preferably twenty channels.

30. (canceled)

31. A photocatalytic reactor comprising: a reaction chamber having a fluid inlet and a fluid outlet displaced in a longitudinal direction of the reaction chamber, at least one stator, comprising a first surface and an opposing second surface, and at least one channel extending between the first surface and the second surface to allow fluid flow through the stator, wherein the at least one channel has a profile shaped to redirect the fluid flow in a direction substantially parallel to the first and/or second surface, located between the fluid inlet and the fluid outlet, and a plurality of mobile photocatalyst particles disposed on the at least one stator.

32-41. (canceled)

42. The photocatalytic reactor as claimed in claim 31 wherein the reaction chamber comprises a plurality of spatially separated cells or sub-chambers, and wherein each cell or sub-chamber comprises a stator comprising a first surface and an opposing second surface, and at least one channel extending between the first surface and the second surface to allow fluid flow through the stator, wherein the at least one channel has a profile shaped to redirect the fluid flow in a direction substantially parallel to the first and/or second surface.

43. (canceled)

44. A method of carrying out a photocatalytic reaction, the method comprising: providing a photocatalytic reactor comprising at least one stator according to claim 1; providing a layer of mobile photocatalyst particles disposed on at least one surface of the stator; providing a flow of fluid through the stator; whereby the fluid flow is redirected in a direction substantially parallel to the at least one surface of the stator.

45-47. (canceled)

48. The method as claimed in claim 44, wherein redirecting the fluid flow sequentially moves the mobile photocatalyst particles around the at least one surface of the stator in a non-continuous path.

49-50. (canceled)

51. The stator as claimed in claim 1, wherein the at least one channel is configured to redirect the fluid flow in a direction substantially parallel to the first and/or second surface to lift and/or roll the photocatalyst particles across the first and/or second surface of the stator.

52. The stator as claimed in claim 1, comprising a hood associated with the at least one channel which redirects the fluid flow and prevents photocatalyst particles entering the at least one channel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Aspects and advantages of the present invention will become apparent upon reading the following detailed description and upon reference to the following drawings (like reference numerals referring to like features) in which:

[0065] FIG. 1 presents a photocatalytic reactor in accordance with the prior art shown in perspective view;

[0066] FIG. 2A presents a photocatalytic reactor stator in accordance with the present invention shown in perspective view;

[0067] FIG. 2B presents an enlarged view of portion B of FIG. 2A, illustrating in profile a single channel through the photocatalytic reactor stator; and

[0068] FIG. 2C presents an enlarged view of portion C of FIG. 2A, illustrating in cross-section a single channel through the photocatalytic reactor stator.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0069] As discussed in the background to the invention above, it is an object of at least one aspect of the present invention to provide a stator that is capable of further improving the performance of a photocatalytic reactor including such a stator. It is recognised that the rate of reaction between a solid phase catalyst and a liquid phase reactant depends on the exposed surface area of the catalyst and the efficiency of diffusion of molecules of the reactant to and from the surface of the catalyst.

[0070] An embodiment of the present invention is illustrated in FIG. 2A and provides a number of advantages over stators employed in prior art reactors, specifically by increasing the effective exposed surface area of photocatalyst particles disposed on the stator and by increasing the interaction of the photocatalyst particles with a fluid to be treated and with a UV light source when in use.

[0071] An improved photocatalytic reactor stator 218 can be seen to comprise a circular disc with a number of channels 230, in this case twenty, which permit fluid communication through the stator 218. Central aperture 240 extends through the stator 218 but is provided to accommodate a central Ultraviolet (UV) light source (not shown) which may extend along the full length of a reactor in which the stator 218 is employed. Accordingly, there is no fluid communication through this aperture 240. Likewise, apertures 242 do not provide fluid communication therethrough, but are provided to help locate and/or retain the stator 218 in a reactor.

[0072] Alternatively the stator 218 may not have a central aperture 240 and instead at least one ultraviolet light source may be provided which may be positioned at various locations in and/or around the reactor.

[0073] Fluid communication through the stator 218 is therefore restricted to the flow paths provided by the channels 230. Preferably, when located in a reactor, seals (not shown) may be provided around the inner and outer perimeters, where applicable, to prevent fluid travelling through the reactor from bypassing the stator 218.

[0074] The channels 230 can be seen to be generally s-shaped in profile, such that fluid enters the channels 230 (via inlet 232) in a substantially horizontal direction and, more importantly, exits the channels 230 (via outlet 234) in a substantially horizontal direction. As such, fluid passing through the stator 218 is, at least initially, directed across the surface of the stator 218. Furthermore, the fluid is directed towards a neighbouring channel 230.

[0075] In use, a layer of mobile photocatalyst particles (not shown) will be disposed on the upper surface of the stator 218. The fluid flow across the surface of the stator 218 from the outlets 234 resulting from the configuration of the channels 230 serves to entrain photocatalyst particles in the fluid flow where they can interact with contaminants as well as being moved across the surface. Furthermore, by at least initially restricting the fluid flow to a direction across the surface of the stator 218, the risk of photocatalyst particles being carried or propelled upwards to a subsequent stator (a complete reactor may include several such stators) where they may become trapped in the inlets of said stator or enter the corresponding channels is significantly reduced. Additional apparatus or components to prevent clogging is therefore not required.

[0076] Movement of the photocatalyst particles across the surface of the stator 218 may improve mass transfer of contaminants from the fluid to be treated to the surface of the photocatalyst particles. An additional benefit may be that the movement of the photocatalyst particles across the surface of the stator 218 will have a scrubbing or cleaning effect on the stator 218. Similarly, the resulting collisions between photocatalyst particles will have a scrubbing or cleaning effect on the photocatalyst particles themselves.

[0077] The outlet 234 of each channel 230 can be seen to comprise a hood 236 which may serve a number of purposes. When not in use, i.e. when there is no fluid flow through the stator 230, the hood 236 prevents photocatalyst particles from settling in the outlet or even falling through the channel. When in use, as well as serving this purpose the hood 236 provides a disturbance in the fluid flow path as indicated by arrow fin FIG. 2B—which further agitates the photocatalyst particles, for example causing them to lift and roll or tumble which increases exposure of the photocatalyst material to contaminants and also to the relevant UV light source.

[0078] Another benefit of directing fluid flow across the surface of the stator 218 is that higher fluid velocities can be accommodated or tolerated without detrimental effects on a reactor system within which the stator 218 is deployed. As noted above, there is a much reduced risk of the photocatalyst particles interfering with the stator above. Furthermore, collisions between photocatalyst particles and/or other frictional interactions (for example with the surface of the stator 218 itself or even the relatively lower velocity fluid immediately above) may serve to reduce fluid and/or photocatalyst particle velocity significantly within a short vertical distance of the stator 218.

[0079] To increase the initial fluid velocity from the outlet 234, which may increase turbulence and/or transport of photocatalyst particles across the stator 218, the outlet 234 may have a cross-sectional area which is less than that of the corresponding inlet 232. This reduction in cross-section creates a jetting effect which provides a relative increase in fluid velocity near the outlet 234. This jetting effect increases the movement of the catalyst and increases turbulence which may cause further rotational movement of the photocatalyst particles.

[0080] The dimensions of the outlet 234 and inlet 232 may be configured to create a jetting effect which results in the photocatalyst particles lifting and moving across or around the stator 218 surface in a non-continuous sequential path. When the photocatalyst particle has moved out of the jet of fluid it falls towards the stator 218 where it may be exposed to a fluid jet of a neighbouring channel 230. This sequential movement of catalyst particles further increases the surface area of the catalyst exposed to the reactant and the light source and increases mass transfer.

[0081] The invention provides an improved photocatalytic reactor stator. The improved stator comprises a first surface and an opposing second surface, and at least one channel extending between the first surface and the second surface to allow fluid flow through the stator. The at least one channel may be configured to redirect the fluid flow in a direction substantially parallel to the first and/or second surface.

[0082] The improved photocatalytic reactor stator improves the performance of a photocatalytic reactor by increasing the mobility of the photocatalyst and thereby increasing the surface area of the catalyst that is exposed to the reactant and the UV light source.

[0083] Another benefit of the improved stator is that it may improve the performance of a photocatalytic reactor by agitating, moving and/or lifting the photocatalyst particles in a non-continuous sequential path around or across the stator surface which may improve the diffusion of reactant molecules to and from an active site of the catalyst and which may increase mass transfer

[0084] Throughout the specification, unless the context demands otherwise, the terms ‘comprise’ or ‘include’, or variations such as ‘comprises’ or ‘comprising’, ‘includes’ or ‘including’ will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers. Furthermore, relative terms such as “up”, “down”, “top”, “bottom”, “upper”, “lower”, “upward”, “downward”, “horizontal”, “vertical” and the like are used herein to indicate directions and locations as they apply to the appended drawings and will not be construed as limiting the invention and features thereof to particular arrangements or orientations. Likewise, the term “inlet” shall be construed as being an opening which, dependent on the direction of fluid flow, may also serve as an “outlet”, and vice versa.

[0085] The foregoing description of the invention has been presented for the purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The described embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilise the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, further modifications or improvements may be incorporated without departing from the scope of the invention as defined by the appended claims.