Fluid treatment apparatus and method

Abstract

A fluid treatment apparatus is described for the treatment of a fluid substance having multiple component substances to control levels of one or more particular component substances. The apparatus has a reactor chamber; a fluid inlet adapted to provide fluid communication from an external supply of a fluid substance to be treated to said reactor chamber whereby said fluid substance may pass into and through said reactor chamber; a fluid outlet adapted to provide a fluid communication from said reactor chamber whereby said fluid substance may pass from said reactor chamber; at least one first electromagnetic radiation (EMR) waveguide, having at least one first waveguide input port operably coupled within said reactor chamber and adapted to couple electromagnetic radiation of a predetermined first wavelength to a fluid substance passing through said reactor chamber. A method for the treatment of a fluid substance is also described.

Claims

1. A fluid treatment apparatus for the treatment of a fluid substance, comprising: a reactor chamber defined by a perimeter wall; a fluid inlet, having an inlet port, adapted to provide fluid communication from an external supply of a fluid substance to be treated to said reactor chamber whereby said fluid substance passes into and through said reactor chamber, the fluid inlet has an outwardly progressively flare and a curved profile; a fluid outlet, having an outlet port, adapted to provide a fluid communication from said reactor chamber whereby said fluid substance passes from said reactor chamber; at least one electromagnetic radiation (EMR) waveguide, having an optical interface comprising a first interface member operably coupled to a waveguide input port and a second interface member operably coupled to a waveguide output port, said waveguide input port and said waveguide output port are operably coupled to diametrically opposed spaced apart locations on said perimeter wall of said reactor chamber and adapted to couple electromagnetic radiation of a predetermined first wavelength to a fluid substance passing through said reactor chamber, and wherein the outwardly progressing flare and curved profile of said fluid inlet is shaped so that said fluid substance received from said fluid inlet is forced into a continuous swirling flow when passing through said reactor chamber towards said fluid outlet, and wherein the outwardly progressing flare and curved profile of said inlet port is adapted to change an initial fluid pressure of said fluid substance to a predetermined first fluid pressure when passing through said fluid inlet port into said reactor chamber, and wherein said outlet port is adapted to change a chamber fluid pressure of said fluid substance to a predetermined second fluid pressure when passing through said fluid outlet port into said fluid outlet.

2. A fluid treatment apparatus according to claim 1, wherein said electromagnetic radiation (EMR) waveguide comprises first and second EMR couplers provided at respective waveguide input port and waveguide outlet port, such as to be operably coupled across a full width of a reactor volume defined within said reactor chamber.

3. A fluid treatment apparatus according to claim 2, wherein said first interface member and said second interface member comprise portions of the wall adapted to be at least partly transparent to electromagnetic radiation of a predetermined wavelength.

4. A fluid treatment apparatus according to claim 3, wherein each of the first interface member and the second interface member comprise apertured portions of the wall having a closure plug fabricated from a material at least partly transparent to electromagnetic radiation of a predetermined wavelength.

5. A fluid treatment apparatus according to claim 4, wherein each interface member comprises an apertured portion of the wall provided with a glass closure plug.

6. A fluid treatment apparatus according to claim 3, wherein said at least one electromagnetic radiation (EMR) waveguide comprises a first EMR coupler operably coupled to said waveguide input port and to said first interface member, and a second EMR coupler operably coupled to said waveguide output port and to said second interface member.

7. A fluid treatment apparatus according to claim 1, wherein the reactor chamber is configured and the predetermined wavelength is selected such that in use a standing wave is generated.

8. A fluid treatment apparatus according to claim 1, wherein the predetermined wavelength is between 1 mm and 1 m at a respective frequency spectrum of 300 GHz to 300 MHz (microwave).

9. A fluid treatment apparatus according to claim 8, wherein the predetermined wavelength is between 3 mm and 0.6 m at a respective frequency spectrum of 100 GHz to 500 MHz.

10. A fluid treatment apparatus according to claim 1, further comprising a fluid substance supply source fluidly coupled to the fluid inlet to enable supply of a fluid substance to be treated to said reactor chamber.

11. A fluid treatment apparatus according to claim 10, further comprising a fluid substance discharge conduit fluidly coupled to the fluid outlet to enable the fluid substance to pass from and be conveyed away from said reactor chamber.

12. A fluid treatment apparatus according to claim 10, further comprising a heater assembly, fluidly coupled between the fluid substance supply source and the reactor chamber, and adapted to transfer energy to the fluid substance, so as to supply the fluid substance at a predetermined temperature into the reactor chamber.

13. A fluid treatment apparatus according to claim 1, further comprising an electromagnetic radiation (EMR) generator to generate electromagnetic radiation (EMR) of a predetermined wavelength, operably coupled to said waveguide input port.

14. A fluid treatment apparatus according to claim 13, wherein the EMR generator further comprises an input transmission line, operably coupleable to said waveguide input port of said at least one electromagnetic radiation (EMR) waveguide, and an output transmission line, operably coupleable to said waveguide output port of said at least one electromagnetic radiation (EMR) waveguide, wherein said microwave generator, said input transmission line and said output transmission line are adapted to form a closed-loop EMR circuit with said at least one electromagnetic radiation (EMR) waveguide.

15. A fluid treatment apparatus according to claim 13, wherein the EMR generator is a microwave generator and the generated electromagnetic radiation has a wavelength between 1 mm and 1 m at a respective frequency spectrum of 300 GHz to 300 MHz (microwave).

16. A fluid treatment apparatus according to claim 15, wherein the generated electromagnetic radiation has a wavelength between 3 mm and 0.6 m at a respective frequency spectrum of 100 GHz to 500 MHz.

17. A fluid treatment apparatus according to claim 13 wherein said electromagnetic radiation (EMR) generator is any one of a Magnetron, a Klystron, a Gyrotron and a solid-state electronic source.

18. A fluid treatment apparatus according to claim 13, wherein said electromagnetic radiation (EMR) generator is adapted to optimize the coupling between said electromagnetic radiation (EMR) and said fluid substance.

19. A fluid treatment apparatus according to claim 18, wherein said coupling between said electromagnetic radiation (EMR) and said fluid substance is optimized automatically utilizing a predetermined control algorithm.

20. A fluid treatment apparatus according to claim 1, wherein said predetermined first fluid pressure is greater than said initial fluid pressure.

21. A fluid treatment apparatus according to claim 1, wherein said predetermined second fluid pressure is greater than said chamber fluid pressure.

22. A fluid treatment apparatus according to claim 1, wherein said predetermined first fluid pressure is greater than said predetermined second fluid pressure.

23. A method for the treatment of the fluid substance utilizing the fluid treatment apparatus according to claim 1, the method comprising: providing the reactor chamber configured such that the supply of said fluid substance passes into and through said reactor chamber; providing the at least one electromagnetic radiation (EMR) waveguide, having the waveguide input port and the waveguide output port, operably coupled within said reactor chamber and adapted to couple electromagnetic radiation of the predetermined wavelength to the fluid substance passing through said reactor chamber; causing the fluid substance to pass into and through said reactor chamber; causing electromagnetic radiation to pass via the at least one electromagnetic radiation (EMR) waveguide and thereby couple across the reactor chamber.

24. The method of claim 23, comprising operably coupling said waveguide input port and said waveguide output port within said reactor chamber by operably coupling said waveguide input port and waveguide output port to spaced apart locations on a perimeter wall of said reactor chamber, such as to be operably coupled to each other across a reactor volume defined within said reactor chamber.

25. The method of claim 24, comprising operably coupling said first waveguide input port and said first waveguide output port within said reactor chamber by means of an optical interface, for example, wherein the first interface member and the second interface member comprise portions of the wall adapted to be at least partly transparent to electromagnetic radiation of said predetermined wavelength.

26. The method of claim 24, comprising generating a standing wave across the reactor chamber.

27. The method of claim 24, wherein the predetermined wavelength is between 1 mm and 1 m at a respective frequency spectrum of 300 GHz to 300 MHz (microwave).

28. The method of claim 27, wherein the predetermined wavelength is between 3 mm and 0.6 m at a respective frequency spectrum of 100 GHz to 500 MHz.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred embodiments of the present invention will now be described, by way of example only and not in any limitative sense, with reference to the accompanying drawings, in which:

(2) FIG. 1 shows in cross section an apparatus in accordance with an embodiment of the invention suitable for use in an exhaust system of an internal combustion engine;

(3) FIG. 2 shows a schematic of a test system to test the principles of the invention when applied to control vehicle exhaust emissions;

(4) FIGS. 3 to 10 present graphically the results of such test;

(5) FIG. 11 is an illustration of a test set-up of microwave performance within an exhaust;

(6) FIG. 12 is an illustration of energy field distribution in an exhaust comprising (a) a waveguide (diameter 15 mm) and (b) the ARCS device of the present invention (diameter of waveguide 15 mm);

(7) FIG. 13 shows different views (a) (b) and (c) of an example exhaust;

(8) FIG. 14 is an illustration of an example embodiment of a modular ARCS device, where Mica discs are used to couple the ARCS reactor chamber to respective waveguides, (a) front view, (b) side view and (c) semi-transparent perspective view;

(9) FIG. 15 is an illustration of an ARCS device reactor chamber operably coupled to a waveguide installed in a block member suitable to be installed within an exhaust, (a) semi-transparent top view, (b) semi-transparent side view and (c) semi-transparent perspective view;

(10) FIG. 16 is a perspective illustration of an example exhaust comprising the block member shown in FIG. 15;

(11) FIG. 17 is an illustration of an ARCS module chamber assembly, comprising ten operably coupleable ARCS modules, two end plates and a central rod;

(12) FIG. 18 is an illustration of a disassembled ARCS module and two end plates of the ARCS module chamber assembly shown in FIG. 17;

(13) FIG. 19 is an illustration of an alternative embodiment of the ARCS module shown in FIG. 17, which is manufactured from a single block of material;

(14) FIG. 20 is an illustration of the ARCS module of FIG. 19, exploded view, further showing an example plug and an example Mica disc, as well as a central rod;

(15) FIG. 21 is an illustration of an alternative embodiment of the present invention (no waveguide outlet port) where a flange is welded to the mid-portion of an exhaust, (a) sectioned perspective view, (b) top view and (c) exploded view, and

(16) FIG. 22 shows an illustration of the electric field distribution within an exhaust with direct T-shaped feed during use.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

(17) A particular preferred application of the principles of the invention relates to the cleaning of exhaust combustion products, for example in the exhaust stream of a combustion engine. FIG. 1 shows, in cross section, an apparatus in accordance with an embodiment of the invention suitable for use in an exhaust system of an internal combustion engine.

(18) In accordance with the example application of the invention, exhaust flue gases may be cleaned (i.e. reduction of harmful exhaust such as NOX, CO etc.) by providing the apparatus 100 within the exhaust output path. For example, the apparatus 100 may be provided at the exhaust of a combustion engine (e.g. diesel or petrol) of a vehicle to reduce or even remove harmful components from the exhaust gas.

(19) The apparatus 100 includes a main body in the form of an elongate tube 102 with a convex central portion 103 defining an open reactor chamber 104. The two ends of the tube respectively define an inlet and an outlet which in the preferred application will be in fluid communication with and for example incorporated into an exhaust tube (not shown) of a combustion engine. A flow of exhaust gases to be treated may thereby be maintained in use continuously into and through the reactor chamber 104. It is generally desirable for the effective functioning of the invention that the exhaust gases are at an elevated temperature and accordingly the inlet end is preferably located closely downstream of the exhaust manifold. Additionally or alternatively a heater (not shown) may be provided upstream of the inlet.

(20) An EMR waveguide system is provided to couple microwave electromagnetic radiation of a predetermined wavelength across the reactor chamber 104. This includes first and second EMR couplers 120, 122 respectively located at diametrically opposite sides of the widest part of the convex wall 103 that defines the reactor chamber 104. The first and second EMR couplers 120, 122 respectively define a waveguide input port and a waveguide output port which are coupled with a microwave generator (e.g. 0 to 100W input, 2.45 Ghz) and a power source via an input transmission line and an output transmission line shown generally compactly associated together as the surrounding generator assembly 110. The first and second EMR couplers 120, 122 are coupled to respective first and second optical interfaces 124, 126 in the form of glass plugs let into and hermetically sealing apertures in the convex wall 103.

(21) The arrangement thus forms a closed-loop EMR circuit with the microwave generator connected via the input transmission line and output transmission line to the respective EMR couplers 120, 122 which define an EMR waveguide and operably couple the EMR radiation across the cavity in the reactor chamber 104, thus coupling EMR radiation to exhaust gases passing through the reactor chamber. A standing wave W may be generated within the reactor chamber 104 between the first and second optical interface.

(22) In use it is thus possible to couple the EMR radiation across a reaction zone defined in the reactor chamber 104 as exhaust to be treated is passed therethrough. Energy may be imparted to components of the exhaust gas stream passing through the reaction zone in such a manner as to reduce levels of emissions.

(23) After clean-up by the apparatus 100, the exhaust gas may contain a higher percentage of oxygen, so that the cleaned may be recycled into the combustion engine to improve the energy efficiency of the engine. Alternatively, it may be exhausted to atmosphere in conventional manner.

(24) Testing has been carried out of a prototype device, referred to below by the acronym ARCS, as a device for reduction of vehicle emissions.

(25) The test, in summary, involves passing the exhaust gas from a fully warmed diesel vehicle across the ARCS device and logging data during an engine idle using a proprietary workshop 5 gas exhaust emissions analyser. Data logs with the ARCS device active and passive were acquired. The ARCS device has an adjustable input power range of between 1 and 100W. For the current study input power was limited to 45W.

(26) The exhaust gas emissions were analysed using a Sykes Pickavant 5 gas exhaust emissions analyser. The 5 gases analysed are Carbon Monoxide (CO), Carbon Dioxide (CO2), Oxygen (O2), Hydrocarbons (HC) and Nitrogen Monoxide (NO).

(27) Exhaust gases from the dual vehicle exhausts were ducted through two flexible exhaust hoses of approximately 3.3 m length after which they were combined into a single hose using a plastic Y piece. A further hose of approximately 1.8 m connected the Y piece to the ARCS device. As the ARCS hardware had been primarily designed for use in a fuel reformer application a number of adaptors were required to mate the exhaust hoses to the ARCS device. After passing through the ARCS device the exhaust gases exited into a vertically mounted transparent plastic stack pipe of approximately 0.88 m length into which the exhaust analyser probe was inserted. The analyser probe was connected to the analyser with approximately 5 m of transparent hose. A schematic drawing of the hoses up to the ARCS device is included in FIG. 2.

(28) At the start of the test sequence the vehicle was started and idled to allow the engine and exhaust after treatment system to warm up to normal running temperatures. Both the ARCS on and ARCS off tests were performed sequentially during one continuous vehicle idle.

(29) Two tests were performed; one with the ARCS device active and one with the ARCS device passive. Prior to each of the tests the exhaust gas analyser zero check procedure was performed. This procedure involves removing the probe from the test installation and sampling fresh air outside of the workshop environment. After sampling fresh air for 60 s the CO, HC, CO2 & NO readings are zeroed and the oxygen reading is set to 20.9%.

(30) During the set-up of the ARCS on test the vehicle exhaust was disconnected and ducted outside of the workshop, the vehicle remained at idle. At the start of the test the analyser data log was started and the exhaust was reconnected. After a suitable delay to allow the analyser to register the exhaust gas emissions the ARCS device was switched on. Towards the end of the test the ARCS device was switched off and the changes in the exhaust gas emissions were logged. For the ARCS off test the analyser exhaust sample probe was placed in the exhaust ducting after the Y piece and the exhaust gas was ducted outside of the workshop. All emissions data was acquired at a 1 s sample rate.

(31) The results for the ARCS off test are summarised in the following figures:

(32) FIG. 3: CO2 emissions ARCS off

(33) FIG. 4: O2 emissions ARCS off

(34) FIG. 5: CO emissions ARCS off

(35) FIG. 6: NO emissions ARCS off

(36) The analyser was introduced into the exhaust at sample 3. Allowing for a 20 s analyser response delay a mean value for each of the emissions constituents can be calculated between sample 23 and sample 418. These are set out in table 1.

(37) Constituent Mean (Sample 23 -418):

(38) TABLE-US-00001 TABLE 1 ARCS off mean emissions CO2 % 1.72 O2 % 18.26 CO % 0.018 NO ppm 126.53

(39) The results for the ARCS on test are summarised in the following figures:

(40) FIG. 7: CO2 emissions ARCS on

(41) FIG. 8: O2 emissions ARCS on

(42) FIG. 9: CO emissions ARCS on

(43) FIG. 10: NO emissions ARCS on

(44) The ARCS device was switched on at sample 65 and off at sample 311. Allowing for a 20 s analyser response delay a mean value for each of the emissions constituents can be calculated between sample 85 and sample 310. These are set out in table 2.

(45) Constituent Mean (Sample 85 -310)

(46) TABLE-US-00002 TABLE 2 ARCS on mean emissions CO2 % 0.65 O2 % 18.35 CO % 0.040 NO ppm 124.15

(47) Comparison of the ARCS off and ARCS on mean emissions show that with ARCS on the CO2 emissions reduce and the CO emissions increase. The CO2 emissions reduction is approximately 62% and the CO emissions increase is approximately 222%. The O2 and NO emission are similar between the ARCS off and ARCS on tests.

(48) Inspection of the CO2 emissions plots FIG. 4: CO2 emissions ARCS off and FIG. 8: CO2 emissions ARCS on shows that with ARCS on the decrease in mean missions is associated with an increase in variability.

(49) Inspection of the CO emissions plots FIG. 6: CO emissions ARCS off and FIG. 10: CO emissions ARCS on shows that with ARCS on the increase in mean emissions is associated with an increase in variability.

(50) Testing has shown that the ARCS device when running at a modest power level of 45W has the ability to alter the composition of vehicle exhaust emissions as detected by a proprietary workshop 5 gas exhaust emissions analyser. A Reduction of 62% in CO2 emissions and an increase of 222% in CO have been observed. To place the CO emission increase in context petrol engine vehicles are subject to an idle CO emissions test during a UK MOT test. At normal idle the CO emissions must be below 0.3%. As the test work has been carried out on a diesel engine vehicle with inherently low idle CO emissions even with the increased CO emissions the figures are still well below the petrol limits.

(51) In another example, an array assembly of an apparatus embodying the principles of the apparatus 100 may be provided in the flue gas stack of a power plant to clean up the flue gases. In particular, the array assembly may be made of a plurality of reactor units of the apparatus 100 of the present invention arranged so as to form an assembly adapted to fit into the chimney of the flue gas stack, wherein the parallelly arranged plurality of reactor units are operably coupled to either one single EMR source, or a plurality of EMR sources, so as to activate the apparatus 100.

(52) Example(s) of Implementation(s) of Embodiments of ARCS into Exhaust Designs:

(53) When using an embodiment of the apparatus 100 of the present invention, it is important that the power density, the field strength, the gas expansion, the gas recirculation (spin effect) pressure, and the temperature are maintained according to predetermined specifications (suitable for the fluid substance passing through the ARCS reactor chamber 104, as well as, the microwave energy coupled into the fluid substance. Also, the reactor chamber 104 of the apparatus 100 has to be designed, so as to provide the required fluid flow and pressure. The inner wall of the reactor chamber, as well as, the fluid inlet port and the fluid outlet port are shaped so fluid substance entering through the fluid inlet port is forced into a continuous spin or loop (swirl flow) when passing through the reactor chamber 104, therefore, maximizing the time of the fluid substance within the energy field, before the fluid substance exits the reactor chamber 104 through the fluid outlet port. For instance, as shown in FIGS. 14(a)-16, the fluid inlet port and the fluid outlet port may each have an outwardly progressively flare and a curved profile. Both, the fluid inlet port and the fluid outlet port are adapted to increase the fluid pressure when the fluid substance passes through, wherein the fluid pressure imparted by the inlet port is greater than the fluid pressure imparted by the outlet port, therefore, maintaining a positive gas flow from the fluid inlet port to the fluid outlet port. Furthermore, when the pressurized fluid substance enters the reactor chamber 104, a sudden expansion of the fluid may cause the fluid substance to cool down (Joule-Thompson effect).

(54) In one example embodiment, the apparatus 100 of the present invention is operably implemented within an exhaust 200. To be able to demonstrate the advantages provided by the apparatus 100, an exhaust is first tested on its own to show how moisture may affect microwave performance. In the example test shown in FIG. 11, no gas measurement reading changes were observed. The power delivered was 100W.

(55) Referring now to FIG. 12, energy field distribution in (a) the exhaust waveguide 202 (15 mm) and (b) the ARCS waveguide are compared. In the illustrated example, the ARCS waveguide power to volume ratio 50 to 100 times greater compared to the exhaust.

(56) (i) Modular ARCS Assembly:

(57) In case a modular design of the apparatus 300 is used, mica plugs 302 become the interconnecting plugs and also allow one waveguide 304 to be used connecting all modules. This may aid reducing manufacture costs and also maintains a low energy consumption unit. An example of such a modular unit 300 is shown in FIG. 14.

(58) FIG. 15 shows an embodiment where a single modular apparatus 300 (reactor chamber unit only) is operably coupled to a waveguide 304 that is installed within a block 306 suitable to fit within an exhaust 200. The assembly within an exhaust 200 is shown in FIG. 16.

(59) An assembly 400 of ten interconnected modular apparatuses 402 is shown in FIG. 17. Two end plates 404 are provided at respective ends of the assembly 400. A suitable waveguide 406 is provided to be inserted through respective holes of the interconnected modular apparatuses 402. Respective plugs 408 are used to act as fluid inlet and fluid outlet ports. FIG. 18 shows an example embodiment of a single unit of an interconnectable modular apparatus 402 and each end plate 404. In use, the assembly 400 is provided within a block 306 that is then installed within exhaust 200.

(60) (ii) Single Piece ARCS Module:

(61) FIGS. 19 and 20 show an example embodiment of a module 500 comprising a plurality of apparatuses 502. The module is made of a single piece of material (e.g. metal), so as to improve overall assembly strength and ease of use. As shown in FIG. 20, the Mica discs 504 are introduced through respective slots 506 machnined into the module 500. Respective plugs 508 are screwed into the fluid inlet and fluid outlet of each reactor chamber, and a central waveguide 510 passes through the whole length of the module 500.

(62) In yet another embodiment, a single waveguide input may be provided via a T-shaped feed (see FIG. 22) that is provided by a suitable flange portion 600 (see FIG. 21). The flange portion 600 may be welded to the exhaust 200. A typical energy field distribution provided by a T-shaped feed into the exhaust 200 is shown in FIG. 22. In this embodiment, there is no waveguide output port, i.e. a standing wave may be generated by reflection of the EMR at the inner reactor chamber wall.

(63) It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departing from the scope of the invention as defined by the appended claims.