Diesel fuel control valve and system

Claim 1

A compact fuel control valve device adapted for use in a diesel engine fuel supply system including a fuel supply tank, a fuel supply conduit extending from the tank to the diesel engine, and a heated fuel and air conduit extending from the engine to the fuel supply tank for conducting from the engine a mixture of heated fuel and air entrained in the heated fuel, said fuel control valve device comprising a valve body defining a valve chamber having an upper portion and a lower portion, said valve body defining a fuel supply passage extending through said valve body and being connected to the fuel supply conduit for directing fuel from the supply tank through said fuel supply passage to the diesel engine, said valve body further defining a fuel recirculating passage connecting said lower portion of said valve chamber to said fuel supply passage, an annular valve seat surrounding said fuel recirculating passage, a buoyant valve member disposed for generally vertical movement within said valve chamber, a closure element connected to said valve member and positioned adjacent said valve seat for controlling the flow of heated fuel from said valve chamber through said recirculating passage into said fuel supply passage in response to vertical movement of said valve member within said valve chamber, said heated fuel and air conduit being connected to said upper portion of said valve chamber directly above said valve member, the cross-sectional area of said valve chamber being sufficiently small relative to the cross-sectional area of said heated fuel and air conduit to provide for directing all of the mixture of heated fuel and entrained air downwardly within said valve chamber directly upon and around said valve member while the diesel engine is operating, said valve member being positioned to receive and sense the mixture of heated fuel and entrained air flowing downwardly around said valve member such that said valve member responds to the proportions of heated fuel and air within the mixture while air separates from the mixture for conduction to the fuel supply tank by said heated fuel and air conduit, a thermally responsive valve unit positioned within said valve body at the junction of said fuel supply passage and said fuel recirculating passage, and said valve unit including means for controlling the flow of heated fuel through said recirculating passage in response to the temperature of the fuel flowing through said fuel supply passage, to provide a compact valve system for efficiently using the return fuel heated by the engine and adapted to require relatively small space adjacent the engine.