| 摘要 |
<p>A fuel handling system (10) incorporates a reservoir canister (24) within the fuel tank (12) that is enclosed but for a float controlled vapour vent valve (32) with a vent orifice (40) of predetermined size. A second stage pump (42) sends fuel to the engine, with unused fuel being returned to the canister (24) through a bubble separator(46) that removes the entrained fuel vapour bubbles and sends them into a vapour space (50) just below the top of the canister (24). A first stage pump (52) continually runs to send fuel into the canister (24), thereby maintaining the vapour space (50) at a vapour suppressing elevated pressure. When the vapour space (50) grows far enough that the float (36) falls and opens, fuel sent in by the first stage pump (52) and vapour is expelled. The orifice (40) is large enough to allow the vapour to be expelled but small enough, relative to the first stage pump's capacity, that a vapour suppressing pressure is substantially maintained. <IMAGE></p> |
