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Title:
AIR-GAS MIXER FOR INTERNAL COMBUSTION ENGINE
Document Type and Number:
WIPO Patent Application WO/2016/009292
Kind Code:
A1
Abstract:
The present disclosure relates to an efficient, cost effective air-gas mixer for bi-fuel internal combustion engines operating on gaseous and liquid fuel that ensures optimum air-fuel ratio irrespective of fuel in use. The disclosure also provides for cost effective installation of disclosed air-gas mixer on two wheelers as part of CNG conversion kit.

Inventors:
ANGADJI MICHAEL (IN)
Application Number:
PCT/IB2015/054680
Publication Date:
January 21, 2016
Filing Date:
June 23, 2015
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
ANGADJI MICHAEL (IN)
International Classes:
F02D19/02; F02B43/00; F02M21/04
Foreign References:
US5377646A1995-01-03
US5908475A1999-06-01
US20110265770A12011-11-03
Attorney, Agent or Firm:
KHURANA & KHURANA, ADVOCATES & IP ATTORNEYS (UPSIDC Site-IV,Behind-Grand Venice,Kasna Road, Greater Noida,National Capital Region 0, Uttar Pradesh, IN)
Download PDF:
Claims:
I claim:

1. An air-gas mixer for mixing air and gaseous fuel in a bi-fuel internal combustion engine comprising:

an air intake port for receiving air;

an air outlet port for discharge of mixture of air and gaseous fuel, wherein an air passage is created between said air intake port and said air outlet port;

a fuel intake port for intake of gaseous fuel; and

a butterfly valve between said air intake port and said air outlet port configured to take a first position and a second position, wherein the first position creates an annular space for restricted air passage and the second position allows full passage for air flow

2. The mixer of claim 1, wherein said mixer further comprises an annular gas discharge port configured around said air passage, wherein said annular gas discharge port enables even distribution of gas in air flow.

3. The mixer of claim 2, wherein said annular gas discharge port is configured by means of a ring disposed in said air passage.

4. The mixer of claim 1, wherein said air intake port has helical grooves configured around it.

5. The mixer of claim 3, wherein said helical grooves create turbulence in air flow, wherein said turbulence ensures proper mixing of gas and air.

6. The mixer of claim 1, wherein said first position of butterfly valve is configured for efficient combustion of gaseous fuel received from said fuel intake port.

7. The mixer of claim 1, wherein said second position of butterfly valve is configured for efficient combustion of petrol fuel.

8. The mixer of claim 1, wherein said mixer is made of a light-weight material.

9. The mixer of claim 8, wherein said light-weight material is plastic.

10. The mixer of claim 1, wherein said mixer is made using an injection molding process.

11. The mixer of claim 1, wherein said air outlet port is configured for direct fitment on carburetor.

12. The mixer of claim 1, wherein said air intake port is configured to receive an air intake duct.

13. The mixer of claim 1, wherein said first position of said butterfly valve is used for choke function of engine during cold-start.

Description:
AIR-GAS MIXER FOR INTERNAL COMBUSTION ENGINE

TECHNICAL FIELD

[0001] The present disclosure generally relates to the field of internal combustion engine. More specifically, it pertains to air-gas mixer for bi-fuel internal combustion engine running on two fuels - petrol and CNG.

BACKGROUND

[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] A large number of people especially where public transport is not well developed, are dependent on personal vehicles for their transportation needs. Almost all these vehicles use internal combustion engines (IC engines) as prime mover and fossil fuels like petrol and diesel to run them. These prime movers using petrol or diesel cause pollution both at local level by emitting harmful gases such as nitrogenous oxides and particulates and also at global level by adding to greenhouse gases. However efforts to develop alternatives such as electrically driven personal transport depending on renewable sources of energy for driving personal transport have so far failed to cross the bar of commercial viability.

[0004] Till such time newer technologies bring about radical change in the way transport vehicles are fueled, environmental challenges are being met by laying down pollution control requirements for fossil fuel driven vehicles which require these vehicles to restrict their emissions within the prescribed limits. Engine/vehicle designers and manufacturers are continuously improving the engine designs and exhaust systems to reduce emission levels and meet the statutory requirements.

[0005] One area that can affect pollution from internal combustion engines is choice of fossil fuel. It is known that natural gas (in compressed state to reduce space it would otherwise occupy and therefore Compressed Natural Gas (CNG)), whose main constituent is methane, produces significantly fewer pollutants such as carbon dioxide, unburned hydrocarbons, carbon monoxide, nitrogen oxides, sulfur oxides and particulate matter than petrol or diesel. Besides being less polluting, it has other advantages such as increased life of lubricating oils, no fouling of spark plugs (in case of spark ignition engines), lower maintenance costs etc. It is also safer than other fuels in the event of a spill because natural gas is lighter than air and disperses quickly when released. For aforementioned reasons natural gas is now being extensively used on public transport vehicles in many cities.

[0006] In view of lower cost of CNG and overall economy in operation, it is turning out to be quite popular among individuals for personal transport vehicles also. For this reason many car manufactures are manufacturing models that incorporate CNG as an optional fuel. However requirement of those in lower income segment in developing countries and operating cheaper mode of personal transport such as two wheelers remains unmet. The segment requires low cost solution suitable for fitment on two wheelers both as OE and conversion kit to meet requirement of new as well as already operational two wheelers.

[0007] There is therefore a need for providing efficient, low cost, easy to install air-gas mixer, which can form part of above referred solution.

OBJECTS OF THE INVENTION

[0008] An object of present disclosure is to provide an air-gas mixer that can be installed on two wheelers for conversion to CNG application in a cost effective manner.

[0009] Another object of present disclosure is to provide efficient means for mixing air and CNG in a bifuel internal combustion engine.

[0010] Another object of present disclosure is to provide an air-gas mixer that ensures correct air fuel ratio for optimum performance of engine while operating on gaseous fuel.

[0011] Another object of present disclosure is to provide an air-gas mixer that can be coupled directly in existing air intake system of the engine at carburetor inlet. [0012] Another object of present disclosure is to provide an air-gas mixer that ensures optimum air intake for optimum performance of engine irrespective of fuel i. e. petrol or CNG, in use.

[0013] Another object of present disclosure is to provide an air-gas mixer that ensures proper mixing of gaseous fuel with air by even distribution of gaseous fuel in the air current.

[0014] Another object of present disclosure is to provide an air-gas mixer that ensures proper mixing of gaseous fuel with air by providing turbulence in air current.

[0015] Another object of present disclosure is to provide an air-gas mixer that incorporates choke function for cold start of engine in applications where petrol is liquid fuel.

[0016] Another object of the disclosure is to provide a light-weight cheap to manufacture air-gas mixer, suitable for low cost personal transport vehicles such as two wheelers.

SUMMARY

[0017] Aspects of present disclosure relate to an efficient air-gas mixer for mixing air and gaseous fuel in a bi-fuel internal combustion engine operating on gaseous and liquid fuels. In an aspect, air-gas mixer of the present disclosure ensures optimum intake of air for optimum performance of engine irrespective of fuel i. e. gaseous or liquid, in use.

[0018] In another aspect of the present disclosure, air-fuel mixer ensures even and proper mixing of gaseous fuel by providing means for even distribution of gaseous fuel in the air flowing through the mixer as also means to create turbulence in air current as means for proper mixing.

[0019] In yet another aspect of the disclosure, air fuel mixer incorporates choke function for internal combustion engine for cold starting on liquid fuel such as petrol, thus providing common control for choke and change over from one fuel to another one gaseous and other liquid.

[0020] In another aspect of the disclosure, the air-gas mixer is manufactured using materials and processes which are light weight, cheap and result in economy in mass production making the air-gas mixer suitable for price sensitive low cost applications such as two wheelers with low engine capacity.

[0021] In yet another aspect of the disclosure, the air-gas mixer is configured to fit directly in the air intake system of low capacity typically used on lower end two wheelers and work without loss of efficiency in respect of engine performance.

[0022] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0024] FIG. 1 illustrates perspective view of an exemplary air-gas mixer in accordance with embodiments of present disclosure.

[0025] FIG. 2 illustrates schematic diagram of exemplary configuration of air-gas mixer in accordance with present disclosure.

[0026] FIG. 3(a) illustrates an exemplary cross sectional view of air-gas mixer illustrating internal details in accordance with embodiments of present disclosure.

[0027] FIG. 3(b) illustrates another exemplary cross sectional view of air-gas mixer illustrating internal details in accordance with embodiments of present disclosure

DETAILED DESCRIPTION

[0028] Unless the context requires otherwise, throughout the specification and claims which follow, the word "comprise" and variations thereof, such as, "comprises" and "comprising" are to be construed in an open, inclusive sense that is as "including, but not limited to." [0029] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0030] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. It should also be noted that the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.

[0031] The headings and abstract of the disclosure provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.

[0032] Reference will now be made in detail to the exemplary embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

[0033] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.

[0034] Embodiments of present disclosure describe an efficient air-gas mixer for use on bi- fuel internal combustion engine operating on gaseous and liquid fuels. It may be appreciated that embodiments of the disclosure have been explained with reference to its use in combination with carburetor but the disclosed embodiments can as well be used with suitable modification on other applications and all of these are within the scope of the disclosure.

[0035] In an embodiment, the present disclosure provides a means for controlling air intake through air-gas mixer that have two positions, one for gaseous and other for liquid fuel. The means in each of these positions are configured to permit optimum amount of air for corresponding fuel that ensures optimum efficiency of the engine. In an embodiment of application, the means referred above can be a butterfly valve, which by virtue of its position can change air passage area and therefore amount of air intake and therefore air/fuel ratio.

[0036] In another embodiment, means for controlling air flow can also be configured for choke function for cold starting on liquid fuel such as petrol thus can have common control for choke and change over from one fuel to another - one gaseous and other liquid.

[0037] In another embodiment, the disclosure provides means for intake of gaseous fuel in predetermined ratio of air intake that ensures full utilization of gaseous fuel and optimum power output from engine. In an embodiment of application the means referred above can be a throat in air passage and air intake port configured in such proportions that air to gas ratio is maintained irrespective of amount of air intake.

[0038] In another embodiment, the disclosure provides means for proper and even mixing of gaseous fuel with air that ensures proper full burning of gaseous fuel. In an embodiment of the present application, even distribution of gaseous fuel can be ensured by positioning gas discharge port around circumference of throat of air passage in an annular fashion and mixing of two can be ensured by creating turbulence in air flow by means of helical groves on the peripheral surface of air intake port.

[0039] In another embodiment the air-gas mixer can be configured to be adoptable for manufacture using lightweight materials such as but not limited to plastic of appropriate grade, and in addition, can be configured to be amenable to production using mass production techniques such as but not limited to molding with bare minimum subsequent operations thus making it economical to produce and cheap for end user making the air-gas mixer suitable for price sensitive low cost applications such as two wheelers with low engine capacity.

[0040] FIG. 1 illustrates a perspective view of an exemplary air-gas mixer 100 in accordance with embodiments of present disclosure. The exemplary air-gas mixer 100 can be made up of body 102 and can have air intake port 104 and air outlet port 106 for discharge of mixture of air and gaseous fuel. Body 102 of exemplary air-gas mixture 100 can be configured to incorporate a fuel intake port 108 which can be in shape of a snout for ease of connecting gas delivery pipe (not shown). Within the body 102 of the air-gas mixer 100 can be located means to control air flow such as butterfly valve 110 details of which shall be explained in subsequent paragraphs.

[0041] In an embodiment, air intake port 104 and air outlet port 106 can be configured such that the air-gas mixer 100 can be fitted within the air intake system such as but not limited to between carburetor and air intake hose of an engine without any modifications. Helical groves 112 can be configured on circumferential surface of air passage near the air intake port 104. In an embodiment these helical groves 112 located near the air intake port can be configured to create turbulence in air flow to facilitate proper mixing of gaseous fuel with air.

[0042] FIG. 2 illustrates schematic view 200 of an exemplary air-gas mixer 100 from direction of air intake port 104 in accordance with embodiments of present disclosure. Illustrated therein is an exemplary configuration of means to control amount of air intake such as butterfly valve 110. In an embodiment the butterfly valve 110 can consist of a disc 204 of appropriate shape in conformity with inner air passage of the body 102 and size so as to adequately block air passage within the body 102 of air-gas mixer 100 when placed perpendicular to direction of air flow (across axis of air passage). The disc 204 can be held within the inner air passage of body 102 by means of two shafts - upper shaft 202 and lower shaft 206 - which along with disc 204 can be rotatable within the body 102.

[0043] In an embodiment, size of disc 204 can be smaller than size of air passage and disc 204 can be placed in such a manner as to leave an even annular gap 208 between disc 204 and air passage when positioned across the air passage. This gap 208 can determine amount of air flow through the air-gas mixer 100 in first of the two positions of butterfly valve 110. Other position of butterfly valve 110 can be at 90° of first position in which case disc 204 can be aligned along the path of flow of air in which case air-gas mixer 100 can permit maximum amount of air intake.

[0044] FIG. 2 further illustrates gas intake port 108, which can be configured with plurality of circumferential ribs on outer surface for firm and leak proof fitting of gas delivery pipe (not shown) thereon. Also shown are helical groves 112 which can be configured on the inner peripheral surface of air passage near the air intake port 104 for creating turbulence in air flow that can ensure proper mixing of gaseous fuel with air in accordance with an embodiment of present disclosure. [0045] FIG. 3(a) illustrates an exemplary sectional view 300 of air-gas mixer 100 along section F-F of view 200 in accordance with embodiments of present disclosure. Illustrated therein is configuration of air passage within body 102. Cross section of air passage within the air-gas mixer 100 can gradually reduce from air intake port 104 till a point of minimum cross section - throat 312. Reduction in cross sectional area of air passage can create conducive condition such as reduction in pressure for suction of gaseous fuel from gas discharge port 310.

[0046] In an embodiment gas discharge port 310 can be located around circumference of the throat 312 and can be of annular shape, as shown in figure 3(a), to ensure even distribution of gaseous fuel in the air. Even distribution of gas in air coupled with turbulence in air flow created by means of helical groves 112 can ensure proper and even mixing of two to result in optimum performance of engine.

[0047] FIG. 3(a) also illustrates configuration of gas passage from gas intake port 108 to gas discharge port 310. Gas can travel from gas intake port 108 to gas chamber 308. The gas chamber 308 can be configured around throat 312 between throat wall and outer wall of body 102. Third side of the gas chamber 308 can be defined by ring 306. In an embodiment, the ring 306 can be disposed inside the body 102 and together with throat wall can create contours of gas chamber 308 and gas discharge port 310. The embodiment of ring 306 can facilitate annular gas discharge port 310 and gas chamber 308 without expensive production processes.

[0048] FIG. 3(a) further illustrates configuration of butterfly valve 110 consisting of disc 204, upper shaft 202 and lower shaft 206. The three can be configured within body 102 by means of two holes in body 102 placed diametrically opposite. Upper shaft 202 and lower shaft 206 can be rotatable and thus can permit disc to take any one of two positions - one across air passage and other along air passage - to create two different air intake conditions. An actuating lever 304 can also be configured on lower shaft projecting out of body 102, to move disc butterfly valve from one to other position.

[0049] The air fuel mixer 100 in accordance with embodiments of present disclosure can also incorporate a rubber ring 302 on the air outlet port 106 as illustrated in FIG. 3(a). The rubber ring 302 can be configured such that the air-gas mixer 100 can be fitted on air intake system such as but not limited to carburetor. Likewise air intake port 104 can be sized and configured for fitment of air intake hose of an engine without any modifications. [0050] FIG. 3(b) illustrates an exemplary sectional view 350 of air-gas mixer 100 along section G-G of view 200 in accordance with embodiments of present disclosure. Illustrated therein are two exemplary positions of butterfly valve 110. First position 352 illustrates butterfly valve positioned across air passage with annular gap 208 between valve and inner wall of body 102. In an embodiment, first position 352 can be configured for operation of engine on gaseous fuel for that annular gap 208 is sized to allow optimum amount of air for gaseous fuel application. Second position 354 illustrates butterfly valve positioned along air passage, which can permit maximum amount of air to pass through air-gas mixer 100. In another embodiment second position 354 of air-gas mixer 100 can be configured for operation of engine on liquid fuel and to allow air intake in such a manner as not to affect air fuel ratio and efficiency of the engine.

[0051] In an embodiment first position 352 of butterfly valve 110 can be used for cold start of engine when operating on liquid fuel such as petrol. First position 352 restricts air supply to engine thereby causing carburetor to which air-gas mixer is coupled, to supply rich air fuel mixture to engine suitable for cold starting.

[0052] In another embodiment means for actuating choke for cold start of engine can be connected to actuating lever 304 and can additionally function as means for changeover from one fuel to other. The embodiment can do away with requirement of separate fuel changeover actuating means reducing cost and improving economy of installing conversion kit for use of gaseous fuel.

[0053] Thus the embodiments of present disclosure provide an air-gas mixture that mixes gaseous fuel with intake air in an efficient manner maintaining predetermined and desired gas air ratio and thus can be advantageously used on internal combustion engine for running it on gaseous fuel such as CNG. The air-gas mixer of present disclosure also provides for change over from gaseous to liquid fuel or vice-versa maintaining corresponding air fuel ratios thus providing optimum performance of engine irrespective of fuel in use.

[0054] The air-gas mixer of present disclosure also provides means for configuring it within the air intake system of existing engine and thus can be used as part of conversion kit for CNG application. Embodiments provide for cost effective manufacture and installation that make it suitable for price sensitive segment of two wheeler users. [0055] The above description represents merely an exemplary embodiment of the present invention, without any intention to limit the scope of the present invention thereto. Various equivalent changes, alterations or modification based on the present invention are all consequently viewed as being embraced by the scope of the present invention.

[0056] As used herein, and unless the context dictates otherwise, the term "coupled to" is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms "coupled to" and "coupled with" are used synonymously. Within the context of this document terms "coupled to" and "coupled with" are also used euphemistically to mean "communicatively coupled with" over a network, where two or more devices are able to exchange data with each other over the network, possibly via one or more intermediary device.

[0057] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C ... . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.

ADVANTAGES OF THE INVENTION

[0058] The present disclosure provides efficient means for mixing air and gaseous fuel in an internal combustion engine operating on gaseous as well as liquid fuel.

[0059] The present disclosure provides an air-gas mixer that ensures correct air fuel ratio for optimum performance of engine while operating on gaseous fuel. [0060] The present disclosure provides an air-gas mixer that can be coupled directly with existing air intake system of the engine.

[0061] The present disclosure provides an air-gas mixer that ensures optimum air intake for optimum performance of engine irrespective of fuel i. e. gaseous or liquid, in use.

[0062] The present disclosure provides an air-gas mixer that ensures proper mixing of gaseous fuel with air by even distribution of gaseous fuel in the air current.

[0063] The present disclosure provides an air-gas mixer that ensures proper mixing of gaseous fuel with air by providing turbulence in air current.

[0064] The present disclosure provides an air-gas mixer that incorporates choke function for cold start of engine in applications where petrol is liquid fuel.

[0065] The present disclosure provides a light weight, cheap to produce air-gas mixer suitable for low cost personal transport vehicles such as two wheelers.

[0066] The present disclosure provides an air-gas mixer that can be installed on two wheelers for conversion to CNG application in a cost effective manner.