JPH08178806A - Liquid sample injector - Google Patents

Abstract

PURPOSE: To obtain an apparatus for removing bubbles from the inside of a cylinder and to unclogging a channel through a simple structure without dismantling a machine. CONSTITUTION: In a state where a rotary valve 1 is switched to a suction channel (a), a piston 2b is lowered to suck a predetermined quantity of liquid sample from a container 5 into a cylinder 2a. The rotary valve 1 is then switched to a gas suction channel (d) opened to the atmosphere to lower the piston 2b furthermore, and a predetermined quantity of air is sucked before a switching is made to an auxiliary channel (c) having a closed end. In that state, the piston 2b is elevated or lowered to increase or decrease the inner pressure of the cylinder 2a and then the rotary valve 1 is switched to the supply channel (b) side. Consequently, abrupt pressure variation takes place in the supply channel (b) and the cylinder 2a thus unclogging the channel and removing bubbles adhering to the upper surface of the cylinder 2a or the piston 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid sample injection device for automatically supplying a predetermined amount of liquid sample to an analysis device for analyzing water quality of wastewater, seawater, river water and the like.

[0002]

2. Description of the Related Art In recent years, analyzers for measuring organic and inorganic substances contained in water such as water and sewage water, water for various plants, and water for rivers have been widely used for pollution investigations. A liquid sample injection device is used to supply a predetermined amount of a liquid sample of interest to an analysis system.

The liquid sample injecting device is usually connected to a sample injecting device composed of a cylinder and a piston, a suction passage for sucking the liquid sample and a supply passage for supplying the sucked liquid sample to the analyzing means. The flow path switching means is configured to switch and connect any one of these flow paths and the sample injector. When supplying the liquid sample to the analyzer, first, the piston is lowered in a state where the sample injector and the suction channel are connected to suck a predetermined amount of the sample, and then the sample injector and the suction channel. By switching and connecting and, and raising the piston in this state, a predetermined amount of liquid sample is supplied to the analyzer.

[0004]

However, in such a liquid sample injecting apparatus, as the suction and the pouring operation of the liquid sample are repeated for a long period of time, the flow connected to the flow path switching means due to the change of ambient environment such as the change of temperature. Bubbles may be generated in the passage or inside the sample injector, especially on the upper surface of the piston, which may reduce the accuracy of measurement of the liquid sample, which is a cause of error in the concentration analysis of the liquid sample. Further, if the liquid sample contains foreign matter such as dust, the flow path connected to the flow path switching means may be clogged, making it difficult to inject and discharge the liquid sample.

In such a case, the entire apparatus must be disassembled and cleaned in order to remove the generation of air bubbles and the clogging of the flow path, and these operations must be frequently performed especially when the analysis frequency is high. , Required a lot of work.

In order to solve the above problems, it is an object of the present invention to provide a liquid sample injection device capable of removing the generation of bubbles and the clogging of a flow path with a simpler configuration without disassembling the device.

[0007]

To achieve the above object, a liquid sample injection device according to the present invention comprises a sample injector for sucking and discharging a sample, which is composed of a cylinder and a piston, and at least a liquid sample is sucked. For connecting the sample injector to the sample injector, and a suction channel for supplying the sample liquid to the analyzing means, a suction channel for supplying the sucked liquid sample to the analysis means, and one auxiliary channel. Route switching means,
After connecting the auxiliary flow channel and the sample injector via the flow path switching means, a pressure means for pressurizing or depressurizing the inside of the cylinder in a state where the sample injector and the auxiliary flow path are connected, The inside of the cylinder of the sample injector is pressurized or depressurized via the pressure means, and further, in this state, the flow paths other than the auxiliary flow path are switched and connected to the sample injector via the flow path switching means. And a control means.

[0008]

The operation of the present invention will be described with reference to FIG. 1. With the rotary valve 1 switched to the suction passage a, the piston 2b is lowered to suck the liquid sample from the container 5 into the cylinder 2a by a predetermined amount. Then, the rotary valve 1 is switched to the gas suction flow path d opened to the atmosphere, and the piston 2
After b is further lowered to take in a predetermined amount of air, it is switched to the auxiliary flow channel c whose end is closed. In this state, the piston 2b is raised or lowered to pressurize or depressurize the inside of the cylinder 2a, and then the rotary valve 1 is switched to another passage, for example, the supply passage b. As a result, a sudden pressure change occurs in the supply flow path b and the cylinder 2a, and clogging in the flow path and bubbles adhering to the upper surface of the cylinder 2a or the piston 2b are removed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is an overall schematic view of a liquid sample injection device according to the present invention. In FIG. 1, reference numeral 1 denotes a rotary valve to which a number of channels are connected and which switches the connection between the microsyringe 2 and each channel, a suction channel a for sucking a liquid sample from the container 5, and a liquid in the analysis means 10. A supply flow channel b for supplying a sample, an auxiliary flow channel c closed at the other end, and a gas suction flow channel d opened at the other end to the atmosphere are connected. The microsyringe 2 is mainly composed of a piston 2b and a cylinder 2a, and the vertical movement of the piston 2b injects and withdraws a liquid sample.

The flow path switching operation of the rotary valve 1 and the vertical movement of the piston 2b of the microsyringe 2 are performed by the driving means 3 composed of a motor or the like, and the operation of the driving means 3 is the control means connected to the subsequent stage. Controlled by 4. Then, during the normal analysis operation, the control means 4 issues a command from the analysis means 10 (the signal line is not shown).
Accordingly, first, the rotary valve 1 is driven through the drive means 3.
To the suction channel a, and then the microsyringe 2
Of the liquid sample is sucked into the cylinder 2a, the rotary valve 1 is switched to the supply flow path b to raise the piston 2b, and the analysis means 10 is operated.
A predetermined amount of the liquid sample specified in is supplied. Next, the operation of the present invention for removing air bubbles adhering to the inside of the cylinder 2a and the upper surface of the piston 2b and dust clogging the flow path is controlled by the control means 4
2 will be described based on the flowchart of FIG. The following operations are all performed via the driving means 3.

First, the rotary valve 1 (flow path switching means)
Is switched to connect the suction channel a and the microsyringe 2 (sample injector) (ST1). Next, the piston 2b is lowered to suck a predetermined amount of the liquid sample from the container 5 into the cylinder 2a (ST2), and then the rotary valve 1 is switched to the gas suction flow path d open to the atmosphere (ST3), and the piston is again moved. 2b is lowered to suck a predetermined amount of air into the cylinder 2a (ST4). In this state, two layers of the liquid sample and the air exist inside the cylinder 2a. Next, when the rotary valve 1 is switched to the auxiliary flow path c whose one end is closed (ST5) to reduce the pressure, the microsyringe 2
When the piston 2b is lowered to depressurize the inside of the cylinder 2a (ST6, ST7) and to pressurize, the piston 2b of the microsyringe 2 is raised to pressurize the inside of the cylinder 2a (ST6, ST8).

It should be noted that it is not preferable to discharge the dust or the like to the container 5 or the analyzing means 10 in order to remove the dust or the like clogged in the suction passage a leading to the container 5 or the supply passage b leading to the analyzing means 10. Depressurization is desirable. On the other hand, if dust or the like may be discharged to the outside of the flow path in the gas suction flow path d or another flow path (not shown), it is desirable to pressurize.
Then, while the pressure inside the cylinder 2a is increased / decreased, the rotary valve 1 is switched to a flow passage in which it is desired to remove clogging, bubbles, etc. due to dust, and a sudden pressure change is generated in the changed flow passage and the cylinder 2a (ST9). As a result, dust clogged in the flow path, the inside of the cylinder 2a, or the piston 2b
Bubbles on the upper surface can be removed.

Incidentally, in the above-mentioned embodiment, the liquid sample was injected and then the pressure in the cylinder 2a was increased and decreased.
The purpose is to remove air bubbles adhering to the upper surface of the piston 2b generated when the liquid sample is injected into the cylinder 2a. When the dust and the like clogged in the flow path only need to be removed, the liquid sample is not necessarily sucked. do not have to.

FIG. 3 shows another embodiment of the liquid sample injecting device according to the present invention, which is different from the constitution of FIG. 1 in that the auxiliary channel c is closed at the other end and the driving means 3 is used. The difference is that an auxiliary flow path c ′ in which a pump 6 for pressurizing and depressurizing the operation of which is controlled by the control means 4 is provided is used. Pump 6 for pressurization and depressurization
Is driven in a state where the rotary valve 1 is switched to this auxiliary flow path c ′, and the cylinder 2 of the microsyringe 2 is driven.
Pressurize and depressurize the inside of a. Next, the operation of the liquid sample injection apparatus according to another embodiment of the present invention shown in FIG. 3 will be described based on the flowchart of FIG. 4 showing the operation of the control means 4. All the following operations are the same as in the case of FIG.
Done through.

First, the rotary valve 1 (flow path switching means)
Is switched to the suction channel a (ST11). Next, the piston 2b is lowered to suck a predetermined amount of the liquid sample from the container 5 into the cylinder 2a (ST12), and then the rotary valve 1 is switched to the gas suction passage d opened to the atmosphere (ST).
13), a predetermined amount of air is sucked into the cylinder 2a (S
T14). Then, the rotary valve 1 is switched to the auxiliary flow path c ′ in which the pump 6 is arranged (ST15), and when depressurizing, the pump 6 is evacuated to depressurize the inside of the cylinder 2a (ST16, ST17). ), When pressurizing, the inside of the cylinder 2a is pressurized by operating the pump 6 in reverse (ST16, ST18).

Then, while the pressure inside the cylinder 2a is being increased or decreased, the rotary valve 1 is switched to a flow passage in which it is desired to remove clogging due to dust, bubbles, etc., and a rapid pressure change is generated in the flow passage and the cylinder 2a (ST19). ). As a result, as in the case of the first embodiment, it is possible to remove dust that has clogged the flow path and bubbles that have adhered to the inside of the cylinder 2a or the upper surface of the piston 2b.

[0018]

According to the present invention, by pressurizing or depressurizing the inside of the cylinder of the sample injector, a rapid pressure change is generated in the cylinder and in the flow path. With a simpler structure, it is possible to eliminate the generation of bubbles in the cylinder and the clogging of the flow path.

[Brief description of drawings]

FIG. 1 is an overall view of an embodiment of a liquid sample injection device according to the present invention.

FIG. 2 is a flowchart showing the operation of the control means according to the present invention.

FIG. 3 is an overall schematic view of another embodiment of the liquid sample injection device according to the present invention.

FIG. 4 is a flow chart showing the operation of the control means according to the present invention.

[Explanation of symbols]

 1 ... Rotary valve 2 Micro syringe 2a Cylinder 2b Piston 4 Control means a Suction flow Channel b ... Supply channel c ... Auxiliary channel d ... Gas suction channel

Claims (1)

[Claims] 1. A sample injector comprising a cylinder and a piston for sucking and discharging a liquid sample, at least a suction channel for sucking the liquid sample, and a supply channel for supplying the sucked solution sample to the analyzing means. , And one auxiliary flow path, and a flow path switching means for switching and connecting any one of these flow paths and the sample injector, and a state in which the sample injector and the auxiliary flow path are connected. After connecting the auxiliary flow path and the sample injector via the flow path switching means with the pressure means for pressurizing or depressurizing the inside of the cylinder, the inside of the cylinder of the sample injector is connected via the pressure means. A liquid sample, comprising: pressurizing or depressurizing, and further control means for switching and connecting a channel other than the auxiliary channel and the sample injector via the channel switching means in this state. Injection device