Liquid feeding system
AssigneeHitachi High-Technologies Corporation
InventorsKunihiko Takao, Hironori Kaji, Masahito Ito
Life of this patent
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Abstract
This liquid feeding system has the first and second pumps each of which is provided with a plunger. Liquid sucked through each of the pump suction ports is discharged out of the discharging port through the first pump and/or second pump. Under the starting operation mode, the second pump is stopped and only the first pump is operated. When the discharging pressure at the discharging port reaches up to a predetermined value, the starting operation mode is changed over to the normal operation mode. Under the normal operation mode, the first pump is stopped and only the second pump is operated.
Claims15
A liquid feeding system having first and second pumps with plungers, a suction port and a discharging port so as to suck liquid through said suction port and to discharge said liquid out of said discharging port under operation of said first and second pumps, wherein under a starting operation mode in which said second pump is stopped and only said first pump is operated, the starting operation mode is changed over to a normal operation mode when a discharging pressure at said discharging port reaches up to a predetermined value, and under the normal operation mode, said first pump is stopped and only said second pump is operated.
A liquid feeding system having a first pump, a second pump with plungers, a valve device and a discharging port so as to discharge solution from a source of solution out of said discharging port through said first and second pumps, said valve device has two states, i.e. an opened state where said source of solution and said first pump are connected and said first pump and said second pump are shut off and a closed state where said source of solution and said first pump are shut off and said first pump and said second pump are connected, under the starting operation mode, said valve device is set in said opened state, said second pump is stopped, only said first pump is operated, the starting operation mode is changed over to the normal operation mode when the discharging pressure at said discharging port reaches up to a predetermined value, and under the normal operation mode, said valve device is set to said closed state, said first pump is stopped and only said second pump is operated.
A gradient operation system having a first liquid feeding device for feeding the first solution, a second liquid feeding device for feeding the second solution, and a mixer for mixing solution fed by said first and second liquid feeding device so as to perform a gradient operation for feeding liquid while a mixing ratio between said first solution and said second solution is being changed in a stepwise manner as time passes by, a feed-back gain proportionate to a ratio between the two liquid feeding flow rates is given to a signal for controlling liquid feeding flow rates of said first and second liquid feeding devices.
Dependencies are inferred from the claim text.