Liquid feeding device and fluid chromatograph

Patent metadata

Field	Value
Publication number	US-11307179-B2
Application number	US-201716648077-A
Country	US
Kind code	B2
Filing date	Oct 23, 2017
Priority date	Oct 23, 2017
Publication date	Apr 19, 2022
Grant date	Apr 19, 2022

Abstract

The liquid feeding device includes a discharge speed calculation part configured to calculate a discharge speed v of the plunger pump so that a converted value L ATM under an atmospheric pressure of a flow rate L PRE of the mobile phase discharged to the discharge channel from the pump part becomes a set flow rate L SET using a volume V of the mobile phase in the pump chamber of the closing pump immediately before the precompression process is started, a volume ΔV reduced due to the precompression process of the mobile phase in the pump chamber of the closing pump, and a feeding pressure P; and a discharge operation controller configured to control a discharge speed of the plunger pump to a discharge speed v calculated by the discharge speed calculation part.

First claim

The invention claimed is:

1. A liquid feeding device comprising:
a discharge channel;
a pump part having a plurality of plunger pumps connected in series or in parallel to each other and discharging a mobile phase to the discharge channel, wherein at least one of the plurality of plunger pumps is a closing pump in which communication with the discharge channel is shut off during a non-discharge time during which the closing pump is not executing a discharge process for discharging the mobile phase to the discharge channel;
a feeding pressure sensor detecting a feeding pressure which is a pressure in the discharge channel;
a precompression process execution part configured to, based on at least an output of the feeding pressure sensor, execute a precompression process for causing the closing pump during the non-discharge time after completing a suction process for sucking a liquid into a pump chamber of the closing pump to perform a discharge operation so that a pressure in the pump chamber of the closing pump is substantially equal to the feeding pressure;
a discharge speed calculation part configured to calculate a discharge speed v of the plurality of plunger pumps to obtain a flow rate L PRE of the mobile phase discharged to the discharge channel from the pump part such that a converted value of a flow rate L ATM of the mobile phase under an atmospheric pressure becomes a set flow rate L SET based on a volume V of the mobile phase in the pump chamber of the closing pump immediately before the precompression process is started, and a volume ΔV, reduced due to the precompression process, of the mobile phase in the pump chamber of the closing pump; and
a discharge operation controller configured to control a discharge speed of the plurality of plunger pumps during a discharge process to be the discharge speed v obtained by the discharge speed calculation part.

2. The liquid feeding device according to claim 1 , further comprising a non-discharge time pressure sensor detecting a non-discharge time pressure which is a pressure in the pump chamber of the closing pump during the non-discharge time, wherein
the precompression process execution part is configured to cause the closing pump to perform a discharge operation so that the non-discharge time pressure is substantially equal to the feeding pressure, based on the output of the feeding pressure sensor and an output of the non-discharge time pressure sensor in the precompression process.

3. The liquid feeding device according to claim 1 , wherein the discharge speed calculation part is configured to calculate a compressibility β of the mobile phase using a volume V of the mobile phase in the pump chamber of the closing pump immediately before the precompression process is started, a volume ΔV, reduced due to the precompression process, of the mobile phase in the pump chamber of the closing pump, and the feeding pressure P, and to calculate the discharge speed v of the plunger pump based on the compressibility β and the feeding pressure P.

4. The liquid feeding device according to claim 3 , wherein the discharge speed calculation part is configured to read the feeding pressure P and calculate the discharge speed v of the plurality of plunger pumps using the read feeding pressure P and the latest compressibility β of the mobile phase.

5. The liquid feeding device according to claim 1 , further comprising:
an internal volume calculation part configured to control the closing pump to suck the mobile phase having a known compressibility into the pump chamber of the closing pump and then execute the precompression process, and to obtain information regarding an internal volume of the pump chamber using a discharge operation amount of the closing pump, the feeding pressure, and the compressibility of the mobile phase, in the precompression process; and
an internal volume storage part storing information regarding the internal volume of the pump chamber obtained by the internal volume calculation part, wherein
the discharge speed calculation part is configured to use the information regarding the internal volume stored in the internal volume storage part as a volume V of the mobile phase in the pump chamber of the closing pump immediately before the precompression process is started.

6. A fluid chromatograph comprising:
an analysis channel;
a liquid feeding device according to claim 1 , feeding a mobile phase in the analysis channel;
a sample injection part configured to inject a sample into the analysis channel;
an analytical column provided downstream of the sample injection part on the analysis channel and separating the sample injected by the sample injection part into components; and
a detector provided downstream of the analytical column on the analysis channel and detecting the components separated by the analytical column.

Assignees

• Shimadzu Corp

Inventors

• Yanagibayashi Jun
• Imamura Shinya
• Ogawa Keisuke
• Nikko Masataka
• Fujisaki Shinichi

Classifications

• F04B49/065

  and making use of computers · CPC title

• F04B49/20

  by changing the driving speed · CPC title

• F04B49/08

  Regulating by delivery pressure · CPC title

• F04B23/06 Primary

  the pumps being all of reciprocating positive-displacement type · CPC title

• G01N2030/326

  pumps · CPC title