Modified internal combustion engine and method for utilizing low and medium BTU gaseous fuels

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PRESSURE

PRESSURIZED,

LOW TO MEDUM

BTU GASEOUS

NTERNAL COMBUSTION

ENGINE WITH

MOD FED TMING

MOD FED

CARBURETOR

PRESSURIZED

HGH BTU

GASEOUS FUEL SUPPLY f(35

ENGINE COMBUSTION/

MOD FED TIMING

RESIORTYPE

(SR&RSTION SyNONAL

PRESSURIZED 627 PRESSURE \ MODIFIED

LOW TO MEDIUM

BTU GASEOUS

REGULATOR) V CAERE6R

FUEL SUPPLY

PRESSURIZED

HGH BTU

GASEOUS

FUEL SUPPLY

HGH BTU

CONMENTIONAL

LOUID FUEL

SUPPLY, E.G.

GASOLINE, PUMP

OR GRAVITY FED

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low BTU content, e.g., 100 to 150 BTU's per cubic foot

MODIFIED INTERNAL COMBUSTION ENGINE or medium BTU content, e.g., 300 to 800 BTU per cubic AND METHOD FOR UTILIZING LOW AND foot, can be made from material such as corn, peanut MEDIUM BTU GASEOUS FUELS hulls, celery tops, acetate film and the like. However, so far as is known, internal combustion engines of the

BACKGROUND OF THE INVENTION carburetor type have not previously been adapted to 1. Field of the Invention operate on fuels of relatively low to medium BTU con The invention relates to internal combustion engines tent which for the purpose of the present description is and modifications thereof for utilizing fuels of relatively 10 assumed to mean pressurized gaseous fuels having a low BTU value. BTU content within the range of 100 to 800 BTU's per 2. Description of the Prior Art cubic foot. Among the practical problems that have to Internal combustion engines include both fuel injec be overcome is the starting problem. For example, an tion and carburetor types. Relatively high BTU content internal combustion engine may be made to operate on fuels in liquid form, e.g., gasoline and kerosene, as well 15 a relatively low to medium BTU content gaseous fuel as relatively high BTU content fuels in pressurized but is not capable of starting on such fuel of relatively liquid or gaseous form, e.g., liquified petroleum (LP low to medium BTU content. The present invention gas) and methane, have been employed to operate inter provides an internal combustion engine of the carbure nal combustion engines of the carburetor type. tor type which can both start and operate on low to With the advent of the energy crisis, a need has arisen 20 medium BTU content fuels in pressurized gaseous form for internal combustion engines which can operate on or can, for example, start on a pressurized gaseous or relatively low BTU, i.e., 100 to 800 BTU's per cubic liquid high BTU content fuel and then switch over for foot, fuels in gaseous form which can be made from operation to a low to medium content BTU fuel in corn, peanut hulls, celery tops or other materials which gaseous form. The invention is thus concerned with are known to be convertible to low BTU gaseous fuels. 25 both the nature of the fuel as well as the method of fuel The invention has as its object the provision of a i delivery and in addition with modifications to the con modified internal combustion engine of the carburetor ventional internal combustion engine of the carburetor type capable of operating on a fuel of low to medium type to meet the stated objectives. The fuel supply 10 BTU content, i.e., 100 to 800 BTU's per cubic foot, in represents a pressurized low to medium BTU gaseous pressurized gaseous form or, if necessary, on other fuels fuel supply with the BTU content being as previously of relatively high BTU content in either liquid or gase 30 defined. Fuel supply 10, for example, could represent a ous form. pressurized gaseous fuel made from corn having a BTU SUMMARY OF THE INVENTION content of 310 BTU's per cubic foot and held under an An internal combustion engine of the carburetor type initial pressure in a suitable container at 2000 p.s.i. The gaseous fuel from fuel supply 10 is led through a is modified according to the invention to operate on low 35 suitable to medium BTU fuels, in pressurized gaseous form. be eitherpressure controlled fuel delivery 11 which may under manual or automatic control and which

Modifications are made to the carburetor and timing delivers the gaseous fuel of low to medium BTU con and in providing means for admitting the pressurized tent at an appropriate relatively high, 50 p.s. i., pressure, gaseous fuel to the engine under controlled pressure conditions. Various embodiments allow the modified 40 and at least 25 p.s. i., to the modified carburetor 12 on a engine to selectively use relatively low or high BTU conventional carburetor-type internal combustion en fuels in gaseous form as well as conventional fuels of place gine 15 with the timing modified so that firing takes relatively high BTU content such as gasoline, preferably at top dead center. Modified carbure tor 12 represents a carburetor having a reduced air

DESCRIPTION OF THE DRAWINGS 45 orifice and an increased fuel delivery opening. FIG. 1 is a schematic diagram of a poer system hav As an actual example of a system made according to ing a modified internal combustion engine of the carbu Jeep the invention, a 1970 model, four cylinder, four-cycle retor type and pressurized gaseous fuel supply of low to engine was modified in the following respects. The medium BTU content according to the invention. air orifice was reduced from 1.25 inches in diameter to FIG. 2 is a schematic diagram showing a system 50 0.909 inches in diameter. The conventional carburetor made according to the invention and adapted to selec had twelve holes for admission of fuel, normally pro tively employ either or both a low to medium BTU or pane, and which were originally of 5/32 inch diameter. high BTU content fuel in gaseous pressurized form. The conventional timing vacuum advance on the dis FIG. 3 is a schematic diagram of a system made ac tributor was removed and the timing was set so that cording to the invention which incorporates the system 55 sparking occurred at top dead center. A pressurized of FIG. 2 and in addition makes provision for selective gaseous fuel in a container under an initial pressure of use of a high BTU content fuel in non-pressurized liquid 160 p.s. i. and of 310 BTU content was made from corn form. and was fed to the modified engine 15through the mod

DESCRIPTION OF THE PREFERRED

ified carburetor 12 with the fuel delivery pressure con 60 trol maintaining the delivered pressure of the gaseous

EMBODIMENT fuel at 50 p.s. i. The vehicle was run successfully for It is known that propane gas has a BTU content of several miles and up to a speed of 40 miles per hour and 2900 BTU's per cubic foot, that methane has a BTU with the 5/32' fuel orifices increased to 6/32' diameter. content of 1000 BTU's per cubic foot and that conven While it is believed that the modified engine and tionally, such gaseous relatively high BTU content fuels 65 conversion method and power system of the invention are introduced to an internal combustion engine of the will find widespread application for vehicle operation, carburetor type at relatively low pressure, e.g., 5 p.s. i. It it is anticipated that the invention will also find applica is also known that fuels in gaseous form of relatively tion with stationary internal combustion engines of the

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carburetor type having available low to medium pres according to the mode of engine operation. Since auto surized gaseous fuels for starting and operation pur matic as well as manual timing controls are well-known poses. Also, it is contemplated that portable engine-fuel in the internal combustion engine art, those skilled in systems will be made and become available utilizing the the art will readily understand how engine 40 be present invention. 5 quickly adjusted for either retarded or advanced timing The system of FIG. 2 provides for use of either a of the engine 40 to meet the needs of the particular fuel pressurized low to medium BTU gaseous fuel supply 20 being employed.

or a pressurized high BTU gaseous fuel supply 21. Con In operation, the system of FIG. 3 will, of course, be trol valves 25, 26 feed the selected pressurized gaseous operated according to the desired mode of operation. fuel to an adjustable pressure regulator 30 which, for 10 For example, with valve 63 and valve 81 closed, with example, may provide a dial indication according to BTU regulator 65 set to an appropriate low to medium BTU content, e.g., over a range of 200 to 300 BTU's. BTU setting and with valve 71 open, the engine 40 From pressure regulator 30, the pressurized gaseous would be adapted to operate on a low to medium BTU fuel at the selected pressure is fed to the modified engine content pressurized gaseous fuel from fuel supply 50 by 35 and modified carburetor 36 which may be modified 15 utilizing the modified carburetor 45. In another mode, as previously explained. Since there is a wide variation valve 62 and valve 81 could be closed, valve 63 open, in types of internal combustion engines of the carbure valve 71 closed and the BTU control 65 set to a rela tor type, it is, of course, anticipated that the exact tively high BTU setting under which conditions, engine changes required for reducing the air orifice size and 40 could be operated through modified carburetor 45 increasing the fuel orifice size as well as the exact modi using a high BTU content pressurized gaseous fuel from fications for changing the timing may vary somewhat supply 51. One aspect of the invention that should be from the specific example previously given. Another recognized here is that a modified carburetor according valve 37 may be opened or closed to reduce or increase to the invention can be made to operate on either a the amount of pressurized gaseous fuel entering the pressurized low to medium BTU gaseous fuel or a pres modified carburetor 36. When operating on the low to 25 surized high BTU gaseous fuel with an appropriate medium BTU gaseous fuel from fuel supply 20, valve 37 pressure setting of BTU scaled pressure control 65 and would normally be open so as to admit an increased by closing of valve 71. In another mode, valves 62 and BTU content to modified engine 35. Alternatively, 63 can be closed, valve 81 opened and the timing adjust when operating on the high BTU gaseous fuel from ment 75 set to advance the spark produced by timing supply 21, valve 37 would normally be closed and modi- 30 control 76 and in this mode, engine 40 using the conven fied carburetor 36 would operate with less volume of tional gasoline carburetor 46 would be adapted to oper gaseous fuel being admitted to the engine 35. Reduced ate with a conventional fuel, e.g., gasoline from the fuel admission pressure is used for supply 21. pump or gravity fed supply 52. With regard to timing, The system of FIG. 3 incorporates the system of note should be made that the conventional carburetor FIG. 2 and in addition provides for alternative use of a 35 type internal combustion engine employs ignition tim conventional liquid fuel such as gasoline. The carbure ing which causes the spark to fire prior to full compres tor-type internal combustion engine 40 is provided with sion of the gasoline and air mixture. a pair of dual carburetors comprising a modified carbu What is claimed is:

retor 45 and a conventional carburetor 46. Modified 1. The method of converting a conventional carbure carburetor 45 may be modified as previously explained 40 tor-type internal combustion engine normally operated and the conventional carburetor 46 may partake of any on a gravity or pump fed non-pressurized liquid gaso known conventional form appropriate to the nature of line supply so as to adapt the engine for operation on a the carburetor-type internal combustion engine 40 pressurized supply of gaseous fuel of BTU content being employed. Since use of dual carburetors is a well within the range of 100 to 800 BTU's per cubic foot, known practice those skilled in the art will readily un- 45 comprising the steps of:

derstand the adaptation of modified carburetor 45 and (a) reducing the air orifice size of the carburetor to a conventional carburetor 46 to engine 40 so that engine size appropriate to said BTU content; 40 may operate using either carburetor. (b) increasing the fuel admission orifice size of said Three sources of fuel are provided for the system of carburetor to a size appropriate to said BTU con FIG. 3. Such fuel sources include a pressurized low to 50 tent;

medium BTU gaseous fuel supply 50, a pressurized high (c) retarding the timing of said engine to a retarded BTU gaseous fuel supply 51 and a high BTU non-press timing appropriate to said BTU content; urized conventional fuel supply 52 which can be pump (d) installing means for controlling the pressure at or gravity fed. A control panel 55 includes suitable which said gaseous fuel is admitted through the manual or remote controls 60, 61 for controlling valves 55 said enlarged fuel orifices to said engine; and 62 and 63. Additionally, a BTU scaled control 65 con (e) connecting a supply of said pressurized gaseous trols the setting of pressure regulator 66 which control fuel to said modified carburetor through said pres may also be either manual, electrical or electronic in sure control means.

nature according to known valve control practices. 2. The method of claim 1 including a further conver Another valve control 70 controls valve 71 which com sion adapting said engine to operate on either a supply pares to the previously explained valve 37 of the system of said pressurized gaseous fuel of BTU content within of FIG. 2. Engine 40 is provided with a suitable timing the range of 100 to 800 BTU's per cubic foot or a pres adjustment means 75 connected to an appropriate tim surized gaseous fuel of BTU content substantially in ing control 76 on engine 40 enabling the timing to be excess of said 800 BTU's per cubic foot, comprising the either retarded or advanced according to the nature of 65 additional steps of:

the fuel being admitted to engine 40. Another valve (a) connecting a second supply of pressurized gaseous control 80 controls valve 81 so as to allow fuel from the fuel of BTU content substantially in excess of 800 conventional fuel supply 52 to be either open or closed BTU's per cubic foot to said modified carburetor

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through means enabling selective connection of pared to the volume at which fuel from said first said first or second supply to said modified carbure container is admitted to said engine. tor; and 7. A power system as claimed in claim 3, including: (b) installing means enabling the volume and pressure 5 (a) a second container of fuel in a liquid, non-pressu of fuel supplied to said modified carburetor to be rized state and of BTU content substantially in reduced when supplied from said second supply. excess of 800 BTU's per cubic foot; 3. A power system, comprising: (b) a conventional carburetor on said engine connect (a) a pressurized supply of gaseous fuel of BTU con able to said second container and arranged for selective dual operation with said modified carbu tent within the range of 100 to 800 BTU's per cubic 10 retor;

foot; (c) means to selectively adjust timing of said engine (b) an internal combustion engine of the type nor appropriate to the BTU content of the fuel on mally operated from and normally timed for oper which the engine is operating; and ating from a non-pressurized liquid gasoline supply (d) means for controlling the source of fuel supply and including: 15 admitted to said engine from said containers (i) a carburetor of the type normally operated from thereby enabling said engine to be operated from a non-pressurized liquid gasoline supply and either pressurized gaseous fuel of low to medium having the size of the air orifices thereof reduced BTU content within the range of 100 to 800 BTU's and the size of the fuel admission orifice thereof per cubic foot or from conventional fuel in a liquid, increased to sizes appropriate to said BTU con 20 non-pressurized state of a BTU content substan tent; and tially in excess of 800 BTU's per cubic foot. (ii) timing means for timing said engine and having 8. A power system as claimed in claim 3, including: (a) a second container of pressurized gaseous fuel of a retarded timing appropriate to said BTU con BTU content substantially in excess of 800 BTU's tent; and 25 per cubic foot;

(c) means for connecting said supply to said carbure (b) a third container of fuel in a liquid, non-pressu tor and controlling the pressure at which said fuel rized state and of BTU content substantially in is admitted to said carburetor through said in excess of 800 BTU's per cubic foot; creased size fuel orifice. (c) a conventional carburetor on said engine connect 4. A power system as claimed in claim 3, wherein: 30 able to said third container and arranged for selec (a) said retarded timing is set for firing said engine at tive dual operation with said modified carburetor; top dead center; and (d) means to selectively adjust timing of said engine (b) said means for controlling said pressure maintains appropriate to the BTU content of the fuel on the pressure at which said fuel is admitted to said 35 which the engine is operating; and carburetor to at least 25 p.s.i. (e) means for controlling the source of fuel supply 5. A power system as claimed in claim 3, including: admitted to said engine from said first, second, and third containers thereby enabling said engine to be (a) a second container of pressurized gaseous fuel of operated from either a supply of pressurized gase BTU content substantially in excess of 800 BTU’s ous fuel of low to medium BTU content within the per cubic foot; and 40 range of 100 to 800 BTU's per cubic foot, a pressur (b) means to selectively admit fuel from either said ized gaseous fuel of BTU content substantially in first or second container to said modified carbure excess of 100 to 800 BTU's per cubic foot or from tor to operate said engine. a fuel in a liquid, non-pressurized state of a BTU 6. A power system as claimed in claim 5, including: content substantially in excess of 800 BTU's per (a) means to admit said fuel from said second con 45 cubic foot

tainer to said engine at a reduced volume as con

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UNITED STATES PATENT AND TRADEMARK OFFICE

CERTIFICATE OF CORRECTION

NVENTOR(S) : Salvador L. Camacho

It is Certified that error appears in the above-identified patent and that said Letters Patent is hereby Corrected as shown below:

Col. 1, 1ine 46, 'poer' should be -- power--. Col. 4, line 4, Insert --may-- after '40". signed and escaled this

Ninth Day of March 1952

SEAL

Attest:

GERALD J. MOSSINGHOFF

Attesting Officer Commissioner of Patents and Trademarks