RESERVE FUEL SYSTEM FOR LIQUEFIED GAS POWERED ENGINES

• US 3,710,809 A
• Filed: 01/21/1971
• Issued: 01/16/1973
• Est. Priority Date: 01/21/1971
• Status: Expired due to Term

• Current Assignee: Henry C. Gerfen, Hugh E. Brown, Vourdon H. Fricke
• Original Assignee: Henry C. Gerfen, Hugh E. Brown, Vourdon H. Fricke
• Inventors: Brown, Hugh E., Fricke, Vourdon H., Gerfen, Henry C.
• Primary Examiner(s): Klinksiek, Henry T.
• Assistant Examiner(s): Miller, Robert J.
• Application Number:
  US05/108,308
• Time in Patent Office: 726 Days
• Field of Search: 137/266,256,265,1,10,14,571,572 123/136 62/45,55
• US Class Current: 137/1
• CPC Class Codes: F02M 21/0212 comprising at least 3 C-Atoms, e.g. liquefied petroleum gas [LPG], propane or butane
• CPC Class Codes: F02M 21/0221 Fuel storage reservoirs, e.g. cryogenic tanks
• CPC Class Codes: F02M 21/0239 Pressure or flow regulators therefor
• CPC Class Codes: F02M 21/0242 Shut-off valves; Check valves; Safety valves; Pressure relief valves
• CPC Class Codes: F02M 21/029 Arrangement on engines or vehicle bodies; Conversion to gaseous fuel supply systems
• CPC Class Codes: F02M 21/06 Apparatus for de-liquefying, e.g. by heating
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels
• CPC Class Codes: Y10T 137/0318 Processes
• CPC Class Codes: Y10T 137/4857 With manifold or grouped outlets
• CPC Class Codes: Y10T 137/86187 Plural tanks or compartments connected for serial flow

Abstract

A reserve fuel system for an engine adapted to operate on liquefied petroleum gas (LPG) fuel supplied from a main fuel tank by means of a main fuel line. The system includes an auxiliary fuel line for connecting a reserve fuel tank to the main line for filling the reserve tank with liquefied fuel from the main tank and for supplying the engine with vaporized fuel from the reserve tank when the main tank is empty, and a cut-off valve in the auxiliary line to block communication between the reserve tank and the main line until the fuel in the main tank has been exhausted. The reserve tank is provided with a pressure relief valve to relieve excessive pressure in the reserve tank via the auxiliary line.

Claims

1. A reserve fuel system for an engine operable by liquefied gas fuel from a main tank connected to the engine by a main fuel line comprising a reserve tank, an auxiliary fuel line for connecting the reserve tank to the main line for filling the reserve tank with liquefied fuel from the main tank and supplying vaporized gas fuel to the engine from the reserve tank when the main tank is empty, a cut-off valve in said auxiliary line, and means responsive to increase in pressure in the reserve tank above a predetermined value for relieving pressure in the reserve tank and for returning vented fuel to the main line via the auxiliary line thereby preventing the hazardous venting of fuel to the atmosphere.

2. A system as set forth in claim 1 wherein said main tank delivers fuel to the main line via a main cut-off valve, and wherein there is provided a flow limiting valve controlling the flow through said main line and adapted to terminate substantially all flow from the main tank if the flow rate therethrough incipiently exceeds a predetermined rate, and wherein the auxiliary fuel line is connected to the main line downstream from the main cut-off valve, said system further including means for restricting the rate of flow into the reserve tank to a value less than said predetermined rate.

3. A system as set forth in claim 1 wherein said means for relieving pressure from within said reserve tank comprises a relief valve with its exhaust side in communication with said auxiliary line on the main line side of said auxiliary line cut-off valve.

4. A system as set forth in claim 3 wherein said means for restricting the rate of flow into the reserve tank comprises an orifice within said auxiliary line for restricting the flow rate of liquid fuel into the reserve tank to a value less than said predetermined flow rate and for permitting vaporized gas fuel to flow from the reserve tank to the engine at a flow rate sufficient to supply the engine.

5. A system as set forth in claim 4 wherein said reserve tank has a manually controlled valve for venting fuel therefrom.

6. A system as set forth in claim 5 wherein said auxiliary line, relief valve and vent valve are connected to the portion of said reserve tank which is uppermost when the latter is in its operative position.

7. A system as set forth in claim 4 having a valve body connected to tHe tank, and having said auxiliary line connected thereto, said body having said cut-off valve and also said relief valve and said orifice therein.

8. A system as set forth in claim 7 wherein said relief valve is responsive to pressure differential between the ambient atmospheric pressure and the pressure within the reserve tank.

9. The method of providing a reserve supply of fuel for an engine normally supplied with liquefied gas fuel via a main fuel line from a main tank, comprising:

delivering liquefied gas fuel from the main tank via said main fuel line and an auxiliary fuel line to a reserve tank, thereby to substantially fill it with liquefied gas fuel;

terminating the flow of fuel from the main tank to the main line whenever this flow exceeds a predetermined rate whereby the flow of vaporized gas fuel from the auxiliary fuel line to the reserve tank is restricted to a rate below the predetermined rate;

blocking communication between the filled reserve tank and the main fuel line after filling and until the fuel in the main tank has been exhausted;

placing the reserve tank in communication with the main fuel line; and

supplying vaporized gas fuel to said engine via the auxiliary and main fuel lines to continue to power the engine for a limited period of time after depletion of the main fuel supply.

10. The method of claim 9 which further includes maintaining the pressure in said reserve fuel tank below a predetermined value by relieving the pressure in the reserve tank via the auxiliary line upon any incipient pressure increase in the reserve tank above said predetermined value.