The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 24, 1991
Filed:
Mar. 02, 1990
Dieter Raethel, Mittelstetten, DE;
Christof Schumacher, Krailling, DE;
Wilfried Renovanz, Groebenzell, DE;
Bernhard Umlauf, Seefeld, DE;
Webasto AG Fahrzeugtechnik, , DE;
Abstract
A heater, in particular a motor vehicle heater operated with liquid fuel in which the fuel to be fed to the burner of the heater is preheated using the thermal energy of the combustion gases in the discharge area of the heater to guarantee reliable operation of the heater even at low temperatures, and to prevent paraffin separations, especially with diesel fuel in advance of filter devices in the fuel supply of the burner. For this purpose, a fuel preheating pipe section is provided that can be made in the form of a spiral-shaped pipe loop and that is placed in the flow of combustion gases, which have passed through the heat exchanger of the heater. Since the fuel is warmed in the fuel flow pipe before passage through the filter device, clogging of the filter device is avoided. In accordance with various embodiments the fuel preheating pipe section can be placed in an exhaust gas collecting chamber of the heater or in an exhaust gas discharge connection. Another embodiment feature includes the provision of a second heat exchanger that warms the fuel to being fed to the internal combustion engine using the liquid coolant that was previously warmed in the motor vehicle heater and which also serves as the heat exchange medium for the heat exchanger of the heater.