US 12,031,961 B2
Binary pump and liquid chromatograph
Jun Yanagibayashi, Kyoto (JP)
Assigned to SHIMADZU CORPORATION, Kyoto (JP)
Appl. No. 17/615,561
Filed by SHIMADZU CORPORATION, Kyoto (JP)
PCT Filed Jun. 26, 2019, PCT No. PCT/JP2019/025289
§ 371(c)(1), (2) Date Nov. 30, 2021,
PCT Pub. No. WO2020/261405, PCT Pub. Date Dec. 30, 2020.
Prior Publication US 2022/0252556 A1, Aug. 11, 2022
Int. Cl. G01N 30/32 (2006.01); F04B 41/06 (2006.01); F04B 49/06 (2006.01); G01N 30/02 (2006.01)
CPC G01N 30/32 (2013.01) [F04B 41/06 (2013.01); F04B 49/06 (2013.01); G01N 2030/027 (2013.01); G01N 2030/326 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A binary pump comprising two liquid delivery pumps driven independently of each other, wherein
each of the two liquid delivery pumps includes a primary plunger pump and a secondary plunger pump fluidly connected in series downstream of the primary plunger pump, and is configured to perform continuous liquid delivery by alternately repeating a primary discharge process in which the primary plunger pump performs discharge operation and a secondary discharge process in which the secondary plunger pump performs discharge operation,
each of the liquid delivery pumps includes a primary pressure sensor that detects a pressure in a pump chamber of the primary plunger pump,
the binary pump includes:
a system pressure sensor that detects the system pressure;
an operation state recognition part configured to recognize an operation state which is a position of a plunger of the primary plunger pump and a position of a plunger of the secondary plunger pump of each of the two liquid delivery pumps; and
an operation controller configured to control operation of each of the two liquid delivery pumps, and
the operation controller is configured to cause each of the two liquid delivery pumps to execute, while the secondary discharge process is executed, a suction process, a first pre-pressurizing process, and a standby process in this order, the suction process is for sucking liquid by the primary plunger pump, the first pre-pressurizing process is for causing the primary plunger pump to perform discharge operation until a pressure in a pump chamber of the primary plunger pump becomes a pressure higher than atmospheric pressure and lower than the system pressure, and the standby process is for maintaining a pressure in the pump chamber of the primary plunger pump at a pressure lower than the system pressure until the plunger of the secondary plunger pump reaches a predetermined position,
the operation controller is configured to cause each of the two liquid delivery pumps to execute a second pre-pressurizing process of increasing a pressure in the pump chamber of the primary plunger pump to the system pressure immediately before proceeding from the secondary discharge process to the primary discharge process; and
the operation controller is configured to cause, as long as continuous liquid delivery by each of the two liquid delivery pumps is not interrupted, at least one of the two liquid delivery pumps to execute avoidance operation of interrupting the standby process and proceeding to the second pre-pressurizing process by using the operation state of each of the two liquid delivery pumps recognized by the operation state recognition part, so as to avoid overlap of execution time zones of the primary discharge processes of the two liquid delivery pumps.