Title of Invention

LIQUEFIED PETROLEUM GAS (LPG) VAPOR FUEL METERING SYSTEM FOR STATIONARY BI-FUEL ENGINES

Abstract A Liquefied Petroleum Gas (LPG) vapor fuel metering system for stationary bi-fuel engine, comprising : (i) a fuel cylinder for storing a predetermined quantity of Liquefied Petroleum Gas under pressure. (ii) said fuel cylinder connected to a first stage regulator; (iii) said first stage regulator connected to a second stage metering regulator through a solenoid valve; (iv) said second stage metering regulator connected to a gas-air mixing device through a power screw and (v) said gas-air mixing device connected to an engine through a carburetor wherein : the fuel cylinder comprises a needle valve to draw out LPG in vapor form for supply to the first stage regulator.
Full Text FORM - 2
THE PATENTS ACT, 1970
COMPLETE
SPECIFICATION
SECTION 10
TITLE : LIQUEFIED PETROLEUM GAS (LPG) VAPOR FUEL METERING SYSTEM FOR STATIONARY BI-FUEL ENGINES.
APPLICANT (S) : THE AUTOMOTIVE RESEARCH ASSOCIATION OF INDIA (A
RESEARCH ORGANISATION JOINLY' SET UP BY THE
AUTOMOTIVE INDUSTRY AND MINISTRY OF INDUSTRY,
GOVERNMENT OF INDIA) S.NO. 102, OFF PAUD ROAD, VETAL
HILL, PUNE 411 038, MAHARASHTRA, INDIA & SHRI SHAKTI
LPG LIMITED ADJACENT TO AIRPORT BEGUMPET,
HYDERABAD 500 016, _ - , INDIA.

The following Specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed:-

TITLE:
LIQUEFIED PETROLEUM GAS (LPG) VAPOR FUEL METERING SYSTEM
FOR STATIONARY BI-FUEL ENGINES.
TECHNICAL FIELD:
The present invention relates to the field of vaporized LPG fuel metering system for stationary engines. Particularly, the present invention relates to a system for supplying Liquefied Petroleum Gas (LPG) to bi-fuel stationary engines in response to the load and speed of the engine, such engines preferably being coupled to a portable generator. BACKGROUND ART:
Stationary application engines are popularly known to be powered by fuels such as gasoline, kerosene, diesel etc. because of their cost- effectiveness. Kerosene fired engines which are generally designed based on the physio-chemical characteristics of kerosene, normally possess restricted design such as low compression ratio which results in associated higher level of exhaust emissions.
In an attempt to reduce the exhaust emissions from the engine, use of Liquefied Petroleum Gas as an alternate fuel is one of the best options. Such engines which normally run on kerosene are fitted with 'Add-On' systems which supply Liquefied Petroleum Gas (LPG) as alternate source of fuel to the engine.
Such Add-On systems known in the art generally adopt liquid withdrawal system from the LPG source (tank) for supply of LPG to the engine. The inherent disadvantages of such liquid withdrawal system are as follows:
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i) a heating circuit is required to vaporize the liquid withdrawn, thereby requiring additional heating and associated components and hence cannot be used for air cooled engines; ii) Complexity of the system increases due to large number of fuel supply
components. Our inventors, by determined research and intuitive knawlagehave developed a system for supplying fuel to stationary engines which would overcome the drawbacks of the existing Add-On system and provide an improved LPG Fuel Supply System to the stationary engine by withdrawing LPG directly in vapor form from the LPG source (tank) for metered supply of LPG to the engine. OBJECTS OF THE INVENTION :
1. An object of the present invention is to provide an improved fuel supply system wherein efficient fuel supply is achieved with less number of components.
2. Another object of the present invention is to provide a fuel supply system wherein optimum quantity of LPG is supplied in response to load and speed of the engine.
3. An object of the present invention is to provide a fuel supply system wherein power loss at wide open throttle (WOT) is minimized
4. Yet another object of the present invention is to provide a fuel supply system wherein emissions such as carbon-monoxide and hydro-carbon gas from the engine are minimized.
5. A further object of the present invention is to provide a fuel supply system
wherein the system is safe enough to use due to the provision of electrical
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LPG would match the natural vaporization rate of LPG under typical engine running conditions.
FIG1: In the embodiment shown, a fuel storage cylinder hereinafter referred to as an LPG cylinder (1) is connected to the inlet of a primary regulator (3) using a high pressure tube. (2) The high pressure tube (2) may be made up of an annealed copper/steel tube.
A needle valve is mounted on the LPG Cylinder (1) to draw LPG in vapour form, from the LPG cylinder (1) for supply to the primary regulator (3). The outlet of the primary regulator (3) is connected to the inlet of an LPG solenoid valve (4). The outlet of LPG solenoid valve (4) is connected to a mechanically operated second stage regulator (5) which is connected to the inlet of a power screw (6). The outlet of the power screw (6) is connected to the inlet of a gas-air mixer (8). The gas-air mixer (8) supplies air-fuel mixture through a carburetor (9) to an engine (12) coupled to a generator. The second stage regulator (5) meters exact quantity of gas as per engine load and speed. The structure and functions of the second stage regulator (5) used in this invention is described in detail and claimed in applicant's co-pending patent application No.654/Mum/1998.
The power screw (6) enables fine tuning of engine rpm and load and thereby adjusts fuel supply to the engine (12) through the gas- air mixer (8). An air cleaner (7) is connected at the inlet of the gas-air mixer (8). A fuel tank (17) storing either kerosene or gasoline is connected to the carburetor (9) through a fuel solenoid valve (13). The LPG solenoid valve (4) and the fuel solenoid valve (13) are controlled through vacuum switch (11) by a selector switch (14) which allows the user to select the fuel either LPG gas or
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kerosene. The power supply to the selector switch (14) and the solenoid valves (13, 4) is provided by a chargeable battery (15). A battery charger (16) is provided to keep the battery optimally charged. Battery charger (16) is activated by means of output of generator (12).
The gas-air mixer (8) m^y be a conventional device capable of mixing air and fuel in desired proportion. During operation of the engine in bi-fuel mode, the gas-air mixer (8) is connected between the carburetor (9) and the air cleaner
(7).
A vacuum switch (11) is provided to sense vacuum created in the running engine and to switch off the solenoid valve (4) ensuring stoppage of gas flow to engine in case there is absence of vacuum. A metallic insulator gasket (10) is provided between the mating faces of the engine (12) and the carburetor (9).
The pumping action of the running engine (12) causes vacuum pressure in the intake system of engine. Due to this pumping action, air starts flowing through the venturi of gas air mixer (8) resulting in a pressure drop across the venturi throat. In response to the pressure drop at the throat, the second stage regulator (5) meters required quantity of gas, for mixing with air at desired air-fuel ratio in the gas air mixer (8). This mixture of air & fuel enters engine for combustion to deliver the required power output. The selector switch (14) switches ON one of the two solenoid valves (4,13) while the other remains OFF. This enables the user to select the desired fuel. The electricity required for the system is provided by the battery (15) which is kept optimally charged Dy the battery charger (16). The vacuum switch (11) senses the vacuum in the engine and switches OFF the gas supply while
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WE CLAIM :
1. A Liquefied Petroleum Gas (LPG) vapor fuel metering system for
stationary bi-fuel engine, comprising :
(i) a fuel cylinder for storing a predetermined quantity of Liquefied Petroleum Gas under pressure.
(ii) said fuel cylinder connected to a first stage regulator;
(iii) said first stage regulator connected to a second stage metering regulator through a solenoid valve;
(iv) said second stage metering regulator connected to a gas-air mixing device through a power screw and
(v) said gas-air mixing device connected to an engine through a carburetor wherein :
the fuel cylinder comprises a needle valve to draw out LPG in vapor form for supply to the first stage regulator.
2. The system as claimed in claim 1, wherein the first regulator is adapted for maintaining constant outlet pressure.
3. The system as claimed in claim 1 or 2 wherein the second stage metering regulator is a mechanically operated device for metering gas in response to the load and speed of the engine.
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4. The system as claimed in claim 1,2 or 3 wherein the power screw is operated for fine tuning of engine rpm and load and thereby adjust fuel supply to the engine through the gas-air mixer.
Dated this 30th day of May, 1999.
FOR THE AUTOMOTIVE RESEARCH ASSOCIATION OF INDIA and SHRI SHAKTI LPG LIMITED
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By their Agent

Documents:

353-bom-1999-cancelled pages(29-03-2003).pdf

353-bom-1999-claims(granted)-(29-03-2003).pdf

353-bom-1999-correspondence(06-06-2007).pdf

353-bom-1999-correspondence(ipo)-(22-10-2003).pdf

353-bom-1999-drawing(29-03-2003).pdf

353-bom-1999-form 1(11-10-1999).pdf

353-bom-1999-form 13(04-11-2003).pdf

353-bom-1999-form 2(granted)-(29-03-2003).pdf

353-bom-1999-form 3(29-09-2003).pdf

353-bom-1999-form 4(10-05-1999).pdf

353-bom-1999-form 4(10-11-2003).pdf

353-bom-1999-power of authority(04-11-2003).pdf

353-bom-1999-power of authority(29-09-2003).pdf

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Patent Number 207333
Indian Patent Application Number 353/BOM/1999
PG Journal Number 30/2007
Publication Date 27-Jul-2007
Grant Date 06-Jun-2007
Date of Filing 29-Sep-2003
Name of Patentee THE AUTOMOTIVE RESEARCH ASSOCIATION OF INDIA AND 2)SHRI SHAKTI LPG LIMITED
Applicant Address S. NO. 102, OFF PAUD ROAD, VETAL HILL, PUNE 411 038, IN THE STATE OF MAHARASHTRA AND ADJACENT TO AIRPORT BEGUMPET, HYDERABAD-500 016.
Inventors:
# Inventor's Name Inventor's Address
1 MR. M. K. CHAUDHARI S. NO. 102, OFF PAUD ROAD, VETAL HILL, PUNE 411 038, IN THE STATE OF MAHARASHTRA AND ADJACENT TO AIRPORT BEGUMPET, HYDERABAD-500 016.
PCT International Classification Number F02D 19/02
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA