JPH09210980A - Liquid crhomatograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a rate-of-flow setting reaching the upper limit of pressure value by presuming the upper limit rate of flow by a max. rate-of-flow presuming means, comparing the obtained value with a new rate of flow set by a rate-of-flow setting means, and prohibiting such a setting operation that the new set rate exceeds the upper limitation. SOLUTION: The upper limit of pressure value P0 is previously stored in an upper limit pressure storing means 22. The rate of flow in the range where the pressurization will never become abnormal, is set by a rate-of-flow setting means 21, and the operation is conducted in normal condition. The set rate of flow F1 is stored in an at-normal set rate storing means 24. The liquid feeding pressure at this time is monitored by a pressure sensor 15, and the latest pressure value P1 is stored in an at-normal pressure storing means 23. Using the upper limit P0, set rate F1, and pressure value P1, the upper limit rate of flow F0 is determined from an expression P1/P0=F1/F0. When a new input of the rate of flow is made by the setting means 21, a comparing means 26 compares the new set rate FS with the upper limit F0, and if FS is greater than F0, it is judged that an abnormal pressurization is likely, and the made setting is canceled 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid chromatograph device using a liquid feed pump.

[0002]

2. Description of the Related Art In a liquid chromatograph, a high-pressure liquid is sent using a liquid sending pump. In the conventional liquid chromatograph device, while setting the upper limit value of the liquid feeding pressure, by monitoring the current pressure of the liquid being fed by the pressure sensor provided on the downstream side of the liquid feeding pump moment by moment, If the pressure sensor detects that the liquid feed pressure has reached the upper limit during liquid feed, the liquid feed is automatically stopped to prevent damage to the equipment due to pressurization when a high pressure abnormality occurs. I was trying to prevent it.

[0003]

However, even if an upper limit value is set for the liquid feeding pressure and the liquid pressure is monitored so as to be less than this value, the apparatus does not stop until the upper limit value is reached and the liquid feeding pressure is reduced. Therefore, even if the upper limit value is not reached, a state in which liquid is delivered at a pressure close to the upper limit value may occur, and if this state continues, any of the device, flow path piping, or column may be damaged. It was

The present invention solves such a problem by making it impossible to set the flow rate so as to reach the upper limit value of pressure so that the liquid cannot be sent at a flow rate which may impair safety due to erroneous operation or the like. The purpose is to

[0005]

The liquid chromatograph analyzer of the present invention, which has been made to solve the above problems, has a flow rate setting means, a pressure detecting means provided in a downstream side flow path of a liquid feeding pump, and a pressure feeding means. An upper limit pressure storage means for storing an upper limit value (P0) of the liquid pressure, a normal time pressure storage means for storing a pressure signal value (P1) from the pressure detection means at the time of normal liquid transfer, Set flow rate at time (F1)
Is stored in the normal-time set flow rate storage means, the pressure signal value (P1) stored in the normal-time pressure flow storage means, the set flow rate (F1) stored in the normal-time set flow rate storage means, and the upper limit pressure storage means. The maximum flow rate estimating means for estimating the upper limit flow rate (F0) from the upper limit value (P0) of the liquid delivery pressure, the upper limit flow rate (F0) estimated by the maximum flow rate estimating means, and a new setting by the flow rate setting means. It is characterized in that it is provided with a comparison means for comparing with the set flow rate (FS), and the new set flow rate (FS) cannot be set so as to be higher than the upper limit flow rate (F0).

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the fact that the flow rate and the pressure are approximately proportional to each other in the liquid being fed is utilized. That is, if the liquid pressure and flow rate at a certain point during liquid transfer are P1 and F1, and the flow rate required for the liquid transfer pressure to reach the upper limit P0 is F0, then P
The relationship between 1, P0, F1 and F0 is P1 / P0 = F1 / F
It can be approximated by the formula of 0.

Here, when the upper limit value P0 at which the device is not damaged is set in advance and the set flow rate is set to F1,
Assuming normal liquid transfer, P at that point
If 1 is measured, the value of F0, that is, the flow rate value required to reach the upper limit value of pressure can be obtained from the above equation.

Therefore, when newly setting the flow rate, it is possible to prevent more than pressurization due to an erroneous operation by making a determination so that the flow rate above the upper limit flow rate value is not set by mistake.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a liquid chromatograph device showing an embodiment of the present invention, and FIG. 2 is a flow chart showing its operation.

In the figure, 10 is a mobile phase tank, 11 is a liquid feed pump, 12 is a sample injection part, 13 is a column, and 14 is a detector. These are standardly equipped in a general liquid chromatograph. It is what has been. Fifteen
Is a pressure sensor, which is provided in the flow path on the downstream side of the liquid feed pump and detects the pressure of the fluid. Reference numeral 20 denotes a control unit, which is specifically configured by a computer having a CPU, a memory, a keyboard, and a CRT. The function of the control unit 20 will be described. As shown in FIG. 1, the keyboard functions as a flow rate setting means 21 for setting the flow rate. The memory has an upper limit pressure storage means 22 for storing the upper limit value (P0) of the liquid supply pressure, and a normal pressure memory for storing the pressure signal value (P1) from the pressure detection means at the time of normal liquid supply. The means 23 functions as the normal-time set flow rate storage means 24 for storing the set flow rate (F1) at the time when the normal liquid feeding is performed. The CPU stores the pressure signal value (P1) stored in the normal-time pressure storage means 23, the set flow rate (F1) stored in the normal-time set flow rate storage means 24, and the liquid feed pressure stored in the upper limit pressure storage means 22. Upper limit (P0
) And the function as the maximum flow rate estimating means 25 for estimating the upper limit flow rate (F0), the estimated flow rate estimated by the maximum flow rate estimating means 25, and the new set flow rate (FS) newly set by the flow rate setting means 21. And a function as a comparison means 26 for comparing The CRT has a function of displaying the result of the comparison means 26. As a matter of course, the control unit 20 also performs general control of other liquid chromatograph devices other than the liquid feeding, but detailed description thereof will be omitted.

Next, the operation of this liquid chromatograph device will be described. The present apparatus stores the upper limit pressure (P0) in the upper limit pressure storage means 22 in advance. The input to the upper limit pressure storage means is input by the device maker at the time of manufacture, but may be changed by the user thereafter by keyboard input.

The flow rate setting means 21 sets an appropriate flow rate, that is, a flow rate in a range in which pressurization is never abnormal, and the apparatus is operated in a normal state. The set flow rate (F1) at this time is stored in the normal set flow rate storage means 24. In addition, the liquid delivery pressure during normal operation is monitored by the pressure sensor 15, and the latest pressure value (P1)
Is stored in the normal pressure storage means 23.

Next, the maximum flow rate estimating means stores the stored upper limit value (P0) of the liquid sending pressure and the stored set flow rate (F1).
), Using the stored pressure signal value (P1), an operation for estimating the upper limit flow rate (F0) is performed. That is, P1 / P
The upper limit flow rate (F0) is obtained by substituting P0, F1 and P1 into the equation of 0 = F1 / F0.

Thereafter, when a new flow rate is input by the flow rate setting means 21, the new set flow rate (FS) is
The comparison means 26 compares the flow rate with the upper limit flow rate (F0). If the new set flow rate (FS) is larger than the upper limit flow rate (F0), abnormal pressurization may occur. Such flow rate setting is canceled without being accepted. At the same time, it is more preferable that the CRT is used to display cancellation and the alarm is used to notify the driver. On the other hand, when the new set flow rate (FS) is smaller than the upper limit flow rate (F0), there is no possibility of abnormal pressurization, so this flow rate setting is accepted and the liquid delivery pump receives the new flow rate set value. Will start driving. After that, the liquid feed pressure at the new flow rate setting is monitored by the pressure sensor 15 as needed and stored in the normal pressure storage means. Also, the new set flow rate is stored in the normal-time flow rate storage means, and the series of operations described above is continued.

In the present embodiment, the set flow rate (F1) is the value input from the flow rate setting means. However, a flow rate sensor is separately provided in the flow channel to measure the current flow rate, and this is set to the set flow rate. You may use as.

[0016]

As described above, in the liquid chromatograph apparatus of the present invention, due to the above configuration, when a set value is input in advance for a flow rate that may cause pressurization abnormality, such a setting is made. Since it is not accepted, the abnormal pressurization due to an erroneous operation is prevented, and the protection against damage due to the pressurization of the device, the piping and the column is surely secured. Therefore, even if a highly dangerous solvent is used, the safety is high.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a liquid chromatograph apparatus according to one embodiment of the present invention.

FIG. 2 is a flowchart showing one embodiment of the present invention.

[Explanation of symbols]

 11: Liquid sending pump 15: Pressure sensor 20: Control unit 21: Flow rate setting means 22: Upper limit pressure storage means 23: Normal pressure pressure storage means 24: Normal time flow rate storage means 25: Maximum flow rate estimation means 26: Comparison means

Claims (1)

[Claims] 1. A liquid chromatograph apparatus for feeding liquid using a liquid feeding pump, flow rate setting means, pressure detecting means provided in a downstream side flow path of the liquid feeding pump, and an upper limit value (P0) of liquid feeding pressure. ) For storing the pressure signal value (P1) from the pressure detection means at the time when the normal liquid feeding is performed, and the set flow rate (F1) at the time point. Is stored in the normal-time set flow rate storage means, the pressure signal value (P1) stored in the normal-time pressure flow storage means, the set flow rate (F1) stored in the normal-time set flow rate storage means, and the upper limit pressure storage means. The maximum flow rate estimating means for estimating the upper limit flow rate (F0) from the upper limit value (P0) of the liquid delivery pressure, the upper limit flow rate (F0) estimated by the maximum flow rate estimating means, and a new setting by the flow rate setting means. Compare with set flow rate (FS) That comparison and means, new set flow rate (FS) is a liquid chromatographic apparatus being characterized in that so as not be set to be the upper limit flow rate (F0) or more.