GB2307293A

GB2307293A - Vehicle exhaust filter

Info

Publication number: GB2307293A
Application number: GB9621565A
Authority: GB
Inventors: Frank Gourley Thompson
Original assignee: Ind & Commercial Entpr Ltd
Current assignee: Ind & Commercial Entpr Ltd
Priority date: 1995-11-16
Filing date: 1996-10-16
Publication date: 1997-05-21
Also published as: GB2307293A8; GB9523358D0; GB9621565D0

Abstract

A device for removing harmful products from vehicle exhaust gasses comprises a housing 2 having a chamber 14 between an exhaust gas inlet port 5 and an outlet port 7. A plurality of air inlet ducts 4 allow air to be drawn into, and combined with exhaust gasses in, the chamber. A coil heating element 11 within the chamber heats the combined gasses to a temperature which causes a chemical reaction within the chamber. The processed gases exit the device through outlet port 7. The chemical reaction may involve the metal of the coil element. Preferably the coil element is powered by the vehicles electrical system. The element is preferably coiled into a helical shape to create turbulence within the housing.

Description

2307293 VEHICLE EXHAUST FILTER

This invention relates to the field apparatus for filtering or otherwise processing theexhaust products of a vehicle.

It is well-known that the exhaust emissions of motor vehicles, cars, lorries and the like contain numerous undesirable waste products which are harmful to both the environment and to human health (for example, carbon monoxide, benzene etc). Catalytic converters seek to reduce the toxicity of the emissions but are notoriously expensive, not only to fit, but also to replace which deters many motorists from using them. Since the reduction of harmful environmental effects depends upon widespread use of devices which reduce harmful emissions, there is thus a need for low-cost, easilyfitted apparatus which achieves this end.

Summary of the Invention

According to the broadest aspect of the invention, therefore, there is provided a device for filtering harmful products from vehicle exhaust emissions comprising a housing attachable to the tailpipe of a vehicle exhaust system and having an exhaust gas inlet port, an outlet port and a chamber there between, the chamber containing a heatable coil element and a plurality of air inlet ducts, whereby, in use, exhaust gases enter the chamber and are combined with air drawn in through the air inlet ducts, the combined gases being heated by said coil element and the thus-processed gases exiting the device through the outlet port.

Preferably, the housing has a first portion of substantially uniform crosssection (which first portion is attachable to the tailpipe of a vehicle exhaust system) a second portion of larger area with respect to the first and a third tapered portion therebetween.

Ideally, said air inlet ducts are tapered towards said second portion of the housing ie, into the chamber and are, ideally, equispaced around the periphery of said tapered portion of the housing. In a particularly preferred form, the tapering of said air inlets begins at the junction between the second and third portions of the housing. Advantageously, at least the internal surfaces of the housing are aluminium.

In a preferred form, the heatable coil element is a highly heatconductive metal alloy and is a single strand coiled filament taken, for example, from a braided wire rope of diameter suitably used in marine haulage. Ideally, the shape of the coil element and/or said tapered air inlet ducts is such as to create a vortex or other turbulence within said chamber when air and exhaust gases pass therethrough.

Preferably, the device of the present invention is powered by the electrical system of the car or other vehicle to which it is attached. In use, the coil element is heated to substantially red-heat. Advantageously, power is automatically supplied to the device of the present invention on actuating the vehicle's starter motor; in a preferred form, power to the device is cut automatically at a pre-determined road speed, for example, 50 kilometres per hour. Alternatively, or in addition, the device is further provided with sensing means which analyse the vehicle speed and/or emission composition, the results of which determine whether the device should be actuated or not.

Advantageously, the outlet port is provided with an end cap constructed from gauze, mesh or the like which substantially protects the interior of the chamber from the ingress of foreign bodies and which reduces the undesired effects of air being drawn into the chamber via the outlet port. Of course, the mesh size will be so chosen that the performance of the exhaust system is not unduly handicapped by this further obstruction to the outflow of the exhaust gases.

In a preferred form, the device is further provided with a secondary chamber adapted to receive liquid (ie, condensed) products of the reaction taking place between the coil element and the exhaust gas/air mixture. Preferably, the secondary chamber includes one or more filters, for example, a granulated charcoal filter.

It will be appreciated that the invention includes within its scope a device substantially as described herein with reference to and as illustrated by any appropriate combination of the accompanying drawings.

Ideally, the device of the present invention is integrally-formed with the vehicle exhaust system. Alternatively, the device may be attachable (ie, as an "add-on") to a conventional vehicle exhaust system. The invention therefore includes within its scope a vehicle exhaust system including a device embodying any of the aspects described above.

Brief Description of the Drawings

Preferred embodiments will now be more particularly described, by way of example only, with reference to the accompanying drawings wherein:

Figure 1 is a perspective view of an exhaust filter embodying the invention; Figure 2 is a top view of the exhaust filter of Figure 1; Figure 3 is a front end view (closed) of the exhaust filter of Figure 1; Figure 4 is a front end view (open) of the exhaust filter of Figure 1; Figure 5 is a schematic cross-sectional view of the exhaust filter of Figures I4, in use; Figure 6 is a schematic cross-sectional view of the exhaust filter with "drip chamber"; Figure 7 is a schematic cross-sectional view of an exhaust system including the exhaust filter of Figures 1-4.

Description of the Preferred Embodiments

Referring to Figures 1-3, the device of the present invention (Ihe exhaust filter") 1 comprises an aluminium housing 2 of substantially circular crosssection. Aluminium is chosen for its low conductivity of heat. The housing 2 is integrally formed in three portions of differing diameter (see particularly Figure 2); a first portion 2A, attachable to the tailpipe of a vehicle's exhaust system, a second portion 2B of larger diameter and a third, tapered, portion 2C therebetween.

The exhaust filter 1 is provided with eight air inlet ducts 4 situated around the periphery of the tapered portion 2C of housing 2.

Housing 2 is further provided a portion 2A with an exhaust inlet port 5 which is able to be clipped onto a conventional vehicle exhaust tailpipe (not shown).

Referring particularly to Figure 1, housing 2 is provided with a collection duct 6 which protrudes radially from housing 2 and through which liquid products of the filtration process can be collected.

Portion 2B of housing 2 is provided with an outlet port 7 which, in use, is covered by an end cap 8. End cap 8 is a knurled ring 9 whose central portion is filled with gauze or mesh 10. End cap 8 is a sliding fit (or could screw) onto the end of outlet port 7.

Turning now to Figure 5, the larger-diameter portion 2B of housing 2 encloses reaction chamber 14 which contains a heatable coil element 11. This is powered by the vehicle's electrical system and is automatically actuated with the vehicle's starter motor. At a pre-determined road speed (for example 50 kilometres per hour) power is automatically cut to coil element 11 as, beyond this speed, the harmful exhaust emissions are not so apparent as when idling or travelling in slow-moving traffic.

is Alternatively, sensing means (not shown) can be provided which monitor the products of the filtration process and/or the speed of the vehicle and, from this information, it is determined whether coil element 11 should be actuated or not.

Coil element 11 is made from a highly conductive metal alloy which has the property of being able to retain heat for a relatively long time. A suitable material is a single strand coiled filament taken from a braided wire rope of suitable diameter for use in marine haulage. Element 11 is coiled into a helical shape; this shape being of importance in creating turbulence within the housing 2. Air inlet ducts 4 are equispaced around the periphery of tapered portion 2C of housing 2 and are tapered towards reaction chamber 14, thus directing air onto coil element 11. The inflow of air is also assisted by the provision of tapered portion 2C itself; an abrupt transition from portion 2A to portion 2B would adversely affect the in-flow of air.

In use, exhaust gases leave the vehicle tailpipe and travel into exhaust filter device 1 in the direction indicated by arrow A in Figure 5. Tlese exhaust gases mix with air which is sucked into filter device 1 through air inlet ducts 4. lle air and exhaust gas mixture then passes over coil element 11 in reaction chamber 14. Coil element 11 will have been heated to red heat prior to the reaction taking place. The flow of the gas mixture over coil element 11 reduces its temperature slightly (perhaps below red heat) but the heat is sufficient to cause a chemical reaction within chamber 14 which may involve the metal of coil element 11, the internal surfaces of aluminium housing 2 as well as the heat/exhaust gas reaction itself.

One of the products of the reaction is water which can be condensed and collected through collection duct 6. A cylindrical drip chamber 13 ("the secondary chamber") which is shown in Figure 6 may be attached to the end of collection duct 6. This drip chamber 13 contains charcoal which further purifies the water product of the reaction.

As can be seen from Figure 7, the exhaust filter device 1 may be clipped onto the end of a conventional vehicle exhaust system 12. Alternatively, the exhaust filter 1 may be integrally-formed as part of the vehicle exhaust system 12.

Emission test results are as follows, where "normal" results were taken from a conventional exhaust system and "test" results are an average of three results taken from an exhaust system fitted with the device of the present invention.

Carbon dioxide:- Normal 13.16 Test 9 Hydrocarbon:- Normal 300 Test 112 Oxygen:- Normal 100 Test 14.6 Carbon monoxide:- Normal 150 Test 170 The following sheets constitute independently conducted emissions tests and analysis.

p 1 C 4:46:00 SWIPLE: 11C1,1 UX.TRACT RAIAGE: G 1, 935 LABEL: 14 0, 4.0 QUAN: A 0, 1.0 J 0 CASE: U 20, 3 454 10.0_ :.lic - DATA. 11M001 #372 CALI: CAU"-AUG #25 SCANS 1 TO 169217 n7 600 800 1000 1200 10:00 19:20 19:40 20:00 20416.

1 1 3: 20 A 1 9 400 6:40 1400 1600 SCAN 2 3: '2 0 26:40TIME --_X MASS SPECTRUM 09/03/95 4:46:00 + 3:28 SAMPLE: 1ICM EXTRACT CONDS.: 40(4f1IN)-300@8(IONIN) #199 TO #2.17 SUMMED - #88 TO #120 X1.00 94 1 )M_ )o. 0 - 1.

D,., 1/Z 60 DATA: M1.1001 #208 CALI: CAL-72AUG #25 66 74 1. L L_ BASE M/Z: 94 RIC: 143360.

.1.771 T 200 70400.

olli 11PSCS SPECTRUM 09/03/91cl 4:46:00 + 4:33 SAMPLE: CICII EXTRACT W261 TO #28,5 SUMMED - C58 TO #70 Xl.00 94 --10.0 50.0 1 -V2 Go DATA: 11M001 #273 CALI: CAL221AUG C75 79 108 EASE 11/2: 94 RIC: 134400.

22019.

--0 1000 AMPLE NT PK 75 A4K 2 1803 iR 573 1000 01 LIBRARY SEARCH 4:46:00 + 4..33 SAMPLE: DCM EXTRACT CONDS.: 40(4MIN)- 300@0(10r1IN) # 261 TO # 285 SUMMED - 1 58 TO # 70 X1.00 z r ii r L r BENEENEMETHANOL DATA: 1.1M001 # 273 CALI: CAL22AUG # 275 BASE MiZ: 94 RIC: 132-351.

SAMPLE MINUS LIBRARY 11 Ibill 1 P 11 . li.

350 '45,0, 0 MASS -SPECTRUM DATA: M1,1001 #385 EASE 1V2: 91 09/03,95 4:46:00 + 9:25 CALI: CAL22AUG #25 RIC: '205824.

SAMPLE: OCI.1 EXTRACT CONDS.: 40(411IN)-300@6(10t1IN) #371 TO #399 SUMMED - #25 TO #90 i'll.00 91 51904.

)0.0_ 50. 0 - M 108 1 122 140 160 180 LIBRARY SEARCH 09/03/95 4:46:00 + 6:22 SAMPLE: 0CM EXTRACT # 3702 TO # 392 SUMMED - # 106 TO # 142 X1.00 41PLE 1000 10.H12.0 WT Ne PK 91 414K 1 7149 -IR 746 1000 0 -1000 DATA: 1.111001 # 382 CALI: CAL22AUG # 25 r 111 BASE 11/2: 91 RIC: 155135.

DENEENE, 1(2-PROPENYLOXY)METHYLI- 11 r 9 SAMPLE MINUS LIBRARY - g - 1. 1 1 1 200 --b- ri 250 M. 0 - jo.o MASS SPECTRUM DATA: 1111001 #449 BASE WIZ: 73 09/03.,'95 4:46:00 + 7:29 CALI: CAL22AUG #25 RIC: 2483-n.

SAMPLE: 11CM EXTRACT CONDS.. 40(411IN)-30C'@(3<10t1IN) #441 TO #457 SUMMED - #70 TO #102 X1.00 73 88 57 91 79 1 6 122 51 60 6 1 5 104 lily 129 144 1/Z so go 100 120 140 160 180 200 51200.

1000 iMPLE H I g. 02 WT M M 88 44K 1 6547 iR K38 1000 0 -1000 I/E 40 LIBRARY SEARCH DATA: M11001 # 449 BASE 11/Z: 73 09/03/95 4:46:00 + 7:29 CALI: CAL22AUG # 25 RIC: 237823.

SAMPLE: DC11 EXTRACT CON115.: 4(3(41.1Il)-30@C,8(IOMIff) # 441 TO # 457 SUMMED - # 70 TO # 102 X1.00 r L I. d._ T - - -.. ' r HEXANOIC ACID, 2-ETHYL- SA11PLE 11INUS LIBRARY i X r 1 1 1 11 9. 1 1 9 9 1 1 1 1 1 1 9 1 1.1..1 .1 o 80 100 120 140 )85 ClAIMS 1. A device for filtering harmful products from vehicle exhaust emissions comprising a housing attachable to the tailpipe of a vehicle exhaust system and having an exhaust gas inlet port, an outlet port and a chamber therebetween, the chamber containing heatable coil elements and a plurality of air inlet ducts, whereby, in use, exhaust gases enter the chamber and are combined with air drawn in through the air inlet duct, the combined gases being heated by said coil element and the thus- processed gases exiting the device through the outlet port.

2.

Claims

A device as claimed in Claim 1 wherein the housing has a first portion of

substantially uniform cross-section (which first portion is attachable to the tailpipe of a vehicle exhaust system) a second portion of larger area with respect to the first and a third tapered portion therebetween.

A device as claimed in Claim 1 or Claim 2 wherein said air inlet ducts are tapered towards said second portion of the housing ie, into the chamber.

4. A device as claimed in any of the preceding claims wherein said air inlet ducts are equispaced around the periphery of said tapered portion of the housing.

A device as claimed in Claim 3 or Claim 4 wherein the tapering of said air inlets begins at the junction between the second and third portions of the housing.

6. A device as claimed in any of the preceding claims wherein at least the internal surfaces of the housing are aluminium.

7. A device as claimed in any of the preceding claims wherein the heatable coil element is a highly-heat conductive metal alloy and is a 1 D single strand coiled filament taken, for example, from a braided wire rope of diameter suitably used in marine haulage.

8. A device as claimed in any of Claims 3-7 wherein the shape of the coil element and/or said tapered air inlet ducts is such as to create a vortex or other turbulence within said chamber when air and gases pass therethrough.

A device as claimed in any of the preceding claims which is powered by the electrical system of the car or other vehicle to which it is attached.

10.A device as claimed in any of the preceding claims wherein, the coil element is heated to substantially red-heat.

11. A device as claimed in any of the preceding claims wherein power is automatically supplied to the device on actuating the vehicle's starter motor.

12.A device as claimed in any of the preceding claims wherein power to the device is cut automatically at a pre-determined road speed, for example, 50 kilometres per hour.

13. A device as claimed in any of the preceding claims wherein the device is further provided with sensing means which analyse the vehicle speed and/or emission position, the results of which determine whether the device should be actuated or not.

14. A device as claimed in any of the preceding claims wherein the outlet port is provided with an end cap constructed from gauze, metal or the like which substantially protects the interior of the chamber from the ingress of foreign bodies and which reduces the undesired effects of air being drawn into the chamber via the outlet port.

1-1 15. A device as claimed in any of the preceding claims wherein the device is further provided with a secondary chamber adapted to receive liquid (ie, condensed) products of the reaction taking place between the coil element and the exhaust gas/air mixture.

16. A device as claimed in Claim 15 wherein the secondary chamber includes one or more filters, for example a granulated charcoal filter.

17. A device as claimed in any of the preceding claims which is integrallyformed with the vehicle exhaust system.

18. A device as claimed in any of Claims 1-16 wherein the device is attachable (ie, as an "add-on") to a conventional vehicle exhaust system.

19. A device for filtering harmful products from vehicle exhaust emissions substantially as described herein with reference to and as illustrated by. any appropriate combination of the accompanying drawings.

20. A vehicle exhaust system including a device substantially as described in any of the preceding claims.