| 摘要 |
PROBLEM TO BE SOLVED: To provide a pump for pressure feeding a fluid, particularly a pump for accurately metering and dispensing (or dosing) a liquid reagent for the selective catalytic reduction of nitrogen oxides in the exhaust gas stream of an internal combustion engine. SOLUTION: The pump includes: an inlet means (3); an outlet means (6); an internal volume disposed between the inlet and outlet means (3) and (6); a first pressure feeding means (12, 30, 45, 48) operable to pressure feed a first volume of fluid from the inlet means (3) into the internal volume; and a second pressure feeding means (12, 52) operable to pressure feed a second volume of fluid from the internal volume into the outlet means (6). In a first mode of operation of the pump, the first volume of fluid is greater than the second volume of fluid such that when in use, the pressure of the fluid within the internal volume is elevated to a prescribed level above the pressure of the fluid at the inlet means (3). COPYRIGHT: (C)2010,JPO&INPIT |
