| 摘要 |
<p>A metering pulse pump for metering an additive liquid into a liquid carrier under high pressure includes a rapidly reciprocating piston pump having a number of pumping chambers and having an inlet connectable to a source of liquid and an outlet, and an outlet line carrying liquid from the outlet under high pressure; a source of additive liquid; a differential piston pump having an inlet connectable to the source of additive liquid, an inlet check valve, a pumping chamber, an outlet check valve, and an outlet connected to the outlet line; and a connection from one of the reciprocating pump pumping chambers to the differential piston pump feeding high-pressure liquid to start the pumping stroke of the differential piston pump. In one embodiment, a spring is used to return the differential piston on its intake stroke. In a second embodiment, a connection from another of the reciprocating pump pumping chambers, which is out of phase with the first chamber, is used to return the differential piston on its intake stroke.</p> |
