Fuel preheater with vapor lock prevention means

• US 4,463,739 A
• Filed: 08/30/1982
• Issued: 08/07/1984
• Est. Priority Date: 08/30/1982
• Status: Expired due to Fees

• Current Assignee: Norman C. Niblett
• Original Assignee: Norman C. Niblett
• Inventors: Niblett, Norman C.
• Primary Examiner(s): Lazarus, Ronald H.
• Application Number:
  US06/413,137
• Time in Patent Office: 708 Days
• Field of Search: 123/557, 261/144, 261/145, 165/52, 165/51
• US Class Current: 123/557
• CPC Class Codes: F02M 31/10 by hot liquids, e.g. lubricants or cooling water
• CPC Class Codes: F02M 31/16 Other apparatus for heating fuel
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A fuel preheater for heating fuel being supplied through a fuel conduit from a fuel supply to the engine. Fuel heating is accomplished as a result of heat exchange between the fuel and engine coolant flowing in a coolant conduit. The preheater comprises a coolant tube adapted to have heated coolant flow therethrough and a fuel tube adapted to have fuel flow therethrough enroute to the engine. The fuel tube includes a coil having a plurality of convolutions extending around the exterior of the coolant tube and a downstream section extending through the coolant tube. The region of the downstream section between the most downstream convolution and the location at which the downstream section enters the coolant tube is spaced from the coolant tube in a way to minimize the likelihood of vapor lock.

Claims

1. In a liquid-cooled engine having a radiator and an engine block connected thereto by a coolant conduit forming a coolant path, and having a fuel line for conveying fuel from a fuel pump to said engine for combustion, the improvement comprising:

(a) a metallic coolant tube inserted in said coolant path between said radiator and said engine block so as to cause coolant to flow through said coolant tube; and

(b) a metallic fuel tube in said fuel line between said fuel pump and said engine;

(c) said fuel tube being disposed in a generally helical manner around the outside of said coolant tube and in direct contact therewith;

(d) an end convolution of said helical fuel tube being formed to and extending through said coolant tube in direct contact with the coolant therein; and

(e) a portion of said helical fuel tube intermediate said portion in direct contact with said coolant tube and said portion extending through said coolant tube being substantially sapced from and thereby not in contact with said coolant tube.

2. The improvement of claim 1, in which said end convolution is the last convolution in the flow direction of said fuel.

3. The improvement of claim 1, in which said end convolution extends diametrically through the center of said coolant tube.

4. The improvement of claim 1, in which the maximum spacing between said spaced portion of said fuel tube and said coolant tube is generally between 1-1/16 inch and 11/4 inch.

5. The improvement of claim 4, in which the maximum spacing between said spaced portion of said fuel tube and said coolant tube is on the order of 11/8 inch.