Purge and prime fuel delivery system and method

• US 4,706,636 A
• Filed: 12/06/1984
• Issued: 11/17/1987
• Est. Priority Date: 12/06/1984
• Status: Expired due to Fees

• Current Assignee: Davco Manufacturing Corporation (Daimler Truck Holding AG)
• Original Assignee: Davco Manufacturing Corporation (Daimler Truck Holding AG)
• Inventors: Davis, Leland L.
• Primary Examiner(s): Cox, Ronald B.
• Application Number:
  US06/679,375
• Time in Patent Office: 1,076 Days
• Field of Search: 123/557, 123/514, 123/516, 123/452, 123/467, 123/512, 123/513, 123/187.5, 123/517
• US Class Current: 123/557
• CPC Class Codes: F02D 2200/0606 Fuel temperature
• CPC Class Codes: F02D 33/006 depending on engine operating conditions, e.g. start, stop or ambient conditions
• CPC Class Codes: F02M 31/125 Fuel
• CPC Class Codes: F02M 37/0047 Layout or arrangement of systems for feeding fuel fuel injection apparatus characterised by their conduits and venting means F02M55/00; fuel injection apparatus having a common rail F02M63/0225; arrangement of fuel conduits of low pressure fuel injection apparatus F02M69/462
• CPC Class Codes: F02M 37/16 characterised by provision of personally-, e.g. manually-, operated pumps

Abstract

A fuel delivery system particularly useful for supplying petroleum distillate fuels to a fuel combustion device is described. When such device is operated in cold ambient conditions, fuel clogging can occur in the fuel supply lines. In the past, attempts to overcome such problems have been directed toward applying heat to the portions of the conduits subject to restrictions or by introducing solvents into the fuel. These steps are, however, unsatisfactory. In accordance with this invention, the fuel supply conduits are drained of fuel upon shut-down of the associated engine or other fuel fired device. Upon an engine start-up command, a small quantity of fuel is warmed, preferably using an electric immersion type heater. Once a sufficient fuel temperature is reached, the fuel conduits are reprimed with fuel. Since the fuel does not cold soak in these conduits, fuel clogging problems are eliminated. Various methods for venting the fuel supply conduit enabling such purging and priming is described.

Claims

1. A method of preventing fuel clogging in a fuel delivery system of a combustion device due to exposure to low temperatures, said fuel delivery system of the type having a fuel tank and a fuel supply conduit for transmitting said fuel from said fuel tank to said combustion device and a fuel pump for pumping said fuel from said fuel tank to said combustion device comprising the steps of;

providing a vent means for said fuel supply conduit,

purging said fuel supply conduit of fuel when said combustion device is inoperative, said vent means acting to supply gas to said fuel supply conduit during said purging step, whereby substantially all of said fuel is removed from said fuel supply conduit and returned to said fuel tank such that said fuel supply conduit is not subjected to fuel waxing or clogging therein caused by said exposure to low temperatures, and

priming said fuel supply conduit with said fuel prior to operating said combustion device by energizing said fuel pump, said vent means acting to provide an escape for gases trapped in said fuel supply conduit whereby said fuel is available for said combustion device.

5. The method according to claim 1 further comprising;

heating said fuel prior to priming of said fuel supply conduit.

6. The method according to claim 1 wherein said vent means continually vents said fuel supply conduit whereby gases within said fuel supply conduit are vented therefrom.

7. The method according to claim 1 wherein said vent means comprising a conduit which communicates with said fuel supply conduit and said fuel tank.

8. The method according to claim 1 further comprising;

restricting flow within said vent conduit whereby fuel pressure may be supplied to said combustion device.

2. A method of preventing fuel clogging in a fuel delivery system of a combustion device due to exposure to low temperatures, said fuel delivery system of the type having a fuel tank and a fuel supply conduit for transmitting said fuel from said fuel tank to said combustion device and a fuel pump for pumping said fuel from said fuel tank to said combustion device, comprising the steps of;

providing a vent means for said fuel supply conduit,

providing fuel pump means for pressurizing and evacuating said fuel supply conduit,

purging said fuel supply conduit of said fuel when said combustion device is inoperative by causing said fuel pump to evacuate said fuel supply conduit, said vent means acting to supply gas to said fuel supply conduit during said purging whereby fuel is substantially completely removed from said fuel supply conduit and returned to said fuel tank such that said fuel supply conduit is not subject to fuel waxing or clogging therein caused by said exposure to low temperatures, and

priming said fuel supply conduit with fuel prior to operating said combustion device by energizing said fuel pump, said vent means acting to provide an escape for gases trapped in said fuel supply conduit whereby said fuel is available for said combustion device.

9. The method according to claim 2 further comprising;

heating said fuel prior to priming of said fuel supply conduit.

10. The method according to claim 2 wherein said vent means continually vents said fuel supply conduit whereby gases within said fuel supply conduit are vented therefrom.

11. The method according to claim 2 wherein said vent means comprising a conduit which communicates with said fuelsupply conduit and said fuel tank.

12. The method according to claim 2 further comprising;

restricting flow within said vent conduit whereby fuel pressure may be supplied to said combustion device.

3. A method of preventing fuel clogging in a fuel supply conduit of a combustion device due to exposure to low temperatures comprising the steps of;

providing a vent means for said fuel supply conduit,

purging said fuel supply conduit of fuel when said combustion device is inoperative, said vent means acting to supply gas to said fuel supply conduit during said purging step, whereby said fuel is removed from said fuel supply conduit and is therefore not subjected to fuel waxing or clogging therein,

priming said fuel supply conduit with said fuel prior to operating said combustion device, said vent means acting to provide an escape for gases trapped in said fuel supply conduit whereby said fuel is available for said combustion device, and

heating said fuel prior to priming of said fuel supply conduit.

4. A method of preventing fuel clogging in a fuel supply conduit of a combustion device due to exposure to low temperatures comprising the steps of;

providing a vent means for said fuel supply conduit,

providing a fuel pump adapted to pressurize and evacuate said fuel supply conduit,

purging said fuel supply conduit of said fuel when said combustion device is inoperative by causing said fuel pump to purge said fuel supply conduit, said vent means acting to supply gas to said fuel supply conduit during said purging whereby fuel is removed from said fuel supply conduit and is therefore not subject to waxing or clogging,

priming said fuel supply conduit with said fuel prior to operating said combustion device, said vent means acting to provide an escape for gases trapped in said fuel supply conduit whereby fuel is available for said combustion device, and

heating said fuel prior to priming said fuel supply conduit.