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AssigneeHitachi High-Technologies Corporation
InventorsKunihiko Takao, Kenji Hiraku, Isao Hayase, Hironori Kaji, Masahito Ito
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Provided is a liquid chromatograph pump system which sucks eluent from an eluent reserving container, and which feeds pressurized high pressure eluent into a column, wherein a plunger reciprocating in a cylinder is formed on its outer peripheral surface with a stepped part along the sliding diretion of the plunger in the cylinder so as to define a working chamber between the stepper part and the inner wall surface of the cylinder, the flow rate of the liquid chromatograph pump being determined by the volume of the working chamber and the traveling speed of the plunger, thereby it is possible to stably feed a liquid at an extremely low flow rate, and to satisfactorily expel air bubbles upon a start of the liquid chromatograph pump system.
A liquid chromatograph pump comprising a cylinder having an inner wall surface and a plunger reciprocating in the cylinder at a driving speed, the plunger being formed on its outer surface with a stepped part along the driving direction of the plunger so as to define a working chamber having a cross-sectional area between the stepped part and the inner wall surface of the cylinder, wherein the flow rate of the liquid chromatograph pump is determined by both cross-sectional area of the working chamber and driving speed of the plunger.
A liquid chromatograph pump comprising a cylinder having an inner wall surface, and a plunger reciprocating in the cylinder, the plunger being formed on its outer surface with a stepped part along the driving direction of the plunger so as to define a working chamber between the stepped part and the inner wall surface of the cylinder, wherein an end part of the plunger on the side remote from the drive side, is exposed to a gas atmosphere.
A liquid chromatograph pump system comprising a liquid chromatograph pump, a container for reserving a solution, a low pressure pump provided between the liquid chromatograph pump and the container, a first passage for returning eluent discharged from the liquid chromatgraph pump into the container, a second passage for feeding the eluent discharged from the liquid chromatograph pump to an injector, and a change-over valve for changing over communication between the first passage and the second passage.
Dependencies are inferred from the claim text.