A diesel fuel heater system for heating fuel for the engine of a vehicle having a vehicle heater comprising:
- a fuel tank;
- a first fuel line leading into said tank from a vapor separator;
- an injector pump having both a fuel bypass outlet leading into said vapor separator and an inlet leading from a filter;
- a plurality of fuel injectors leading from said injector pump to the engine of said vehicle;
- a fuel line leading from a valve to said filter;
- a vapor separator line leading from said vapor separator to a port leading into said valve;
- a heat exchanger having an inner wall and an elongated heat exchanger element hollow on the interior mounted in said heat exchanger spaced from the inner wall thereof;
- a fuel outlet line leading from said valve to the exterior of said element of said heat exchanger in fluid communication with the space between the inner wall of said heat exchanger and said element, said heat exchanger having an outlet in fluid communication with the interior of said element fluidly coupled to the inlet of a water pump, said inlet of said water pump being fluidly coupled to a vehicle heater;
- said vehicle heater being fluidly coupled to both an outlet from said water pump and an inlet leading into said heat exchanger;
- a second fuel line leading from said fuel tank to an optional fuel pump fluidly coupled to a fluid inlet of said valve;
- said valve having a fuel inlet line in fluid communication with the exterior of said element of said heat exchanger in fluid communication with the space between the inner wall of said heat exchanger and said element;
- and
- said valve including a main body portion having said fuel inlet coupled to said optional fuel pump at one end, said fuel outlet coupled to said vapor separator being disposed at the other end, said main body portion further including both said fuel inlet line and said fuel outlet line communicating with the space between the inner wall of said heat exchanger and said element, said last mentioned fuel outlet line and said last mentioned fuel inlet being in fluid communication with a distribution chamber in said main body portion;
- a mixing chamber having an inner wall disposed in said main body portion in fluid communication with both said last mentioned fuel outlet,
- temperature sensing means associated with said mixing chamber for sensing the temperature of fuel flowing therethrough, said port fluidly coupled to said vapor separator opening into said mixing chamber;
- opening restrictor means coupled to said temperature sensing means associated with said last mentioned port for restricting the degree of opening thereof, said mixing chamber being separated from said distribution chamber by an inner partition wall in said main body portion,
- a spring biased valve coupled to said restrictor means mounted in said mixing chamber having a valve shaft extending through a second opening in said partition wall, a spring surrounding said valve between said valve and the inner wall of said mixing chamber;
- calibration means extending through a hole in said main body portion and into engagement with said valve shaft, said spring biased valve being normally biased into engagement of said valve shaft with said calibration means with said valve closing off the opening through said partition wall whereby,
- when said temperature sensing means senses a higher temperature than it has predetermined to be desirable, said valve shaft expands against said calibration means moving said valve away from said opening through said partition wall allowing cold fuel from said distribution chamber to enter into said mixing chamber thereby dropping the pressure in said distribution chamber;
- with the flow of fuel out of said valve fuel outlet gradually being reduced with less hot fuel entering said mixing chamber, hot fuel also continuing to flow into said mixing chamber through said valve port, said temperature sensing means subsequently stabilizing at a predetermined temperature with said spring of said valve moving said valve away from said opening through said partition wall.