JPH10142114A - Self-weight flowing-down-type pretreatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an self-weight flowing-down-type pretreatment apparatus by which a quantitative measurement can be performed with high reliability. SOLUTION: A quantification means which is provided at an own-weight flowing-down-type pretreatment apparatus is provided with a constant-quantity tank 2 which comprises an injection port 3, an overflow discharge port 4 and a constant-quantity discharge port 5 and with a constant-quantity opening and shutting valve 21 which controls the discharge of a liquid from the constant- quantity discharge port 5. The opening and shutting valve 21 comprises a short- cycle opening and shutting operation during one opening and shutting operation, a liquid in a constant quantity inside the constant-quantity tank is discharged by the opening and shutting operation, and the liquid is quantitatively determined. In a pretreatment such as a diluting treatment in a case in which a liquid sample or a dilution liquid is titrated or analyzed, the constant-quantity opening and shutting valve 21 is opened and shut in a short cycle, the liquid is urged to flow down in the constant-quantity discharge port 5, and the reliability of the liquid by an self-weight flowing-down quantification system is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for performing pretreatment such as dilution in titration and analysis of a liquid sample or a diluent.

[0002]

2. Description of the Related Art Prior to titration and analysis of a liquid sample, it is necessary to perform quantitative measurement of a liquid sample and a diluent, dilution treatment, and the like. Therefore, in order to automate the titration and analysis of a liquid sample, it is necessary to automate the measurement process itself and also the pretreatment. 2. Description of the Related Art Conventionally, there has been known an apparatus using an automatic dispenser or a syringe pump for automating pretreatment such as quantitative dispensing for measuring a minute constant amount of a liquid sample or diluent. In a device using a syringe pump, a piston portion of a syringe is driven by a pump to suck and discharge a liquid, and the driving of the pump is controlled by a control device.

[0003]

A pretreatment apparatus using a conventional automatic dispensing machine or a syringe pump is a pump for driving a syringe or a syringe at each dispensing point or liquid injection point, and a driving apparatus for driving the pump. And the need for a control device, there is a problem that the configuration becomes complicated, and further, as the dilution process becomes more complicated, the configuration of the pipeline becomes more complicated,
There is a problem that the length of the pipe is also long. In addition, when the pipe is long, a chemical such as a liquid sample or a reagent tends to remain in the pipe, so that it is necessary to sufficiently remove the chemical attached to the pipe, and there is a problem in handling the pretreatment device.

In contrast to the above-described quantitative measurement method in which a syringe pump is used to suck and discharge a liquid, an overflow-type self-weight quantitative measurement method that does not use a syringe pump is known. The self-weight determination method is a method that uses the flow of the liquid from the measurement tank by its own weight, and can be formed with a simple configuration without using a device such as a syringe or a pump for driving the syringe.

[0005] However, the self-weight quantitative measurement method is a quantitative measurement method applied to a large tank having a large pipe diameter in a flow path, and is used for a pretreatment device or the like used for titration and analysis of a liquid sample. There is a problem in reliability when applied to a pipe having a small diameter. Generally, on the inner wall of the cylinder, a phenomenon occurs in which a curved surface called a water meniscus is formed due to surface tension generated on the inner surface of the tube. The liquid that is stationary in the pipe may adhere to the inner wall surface due to the water meniscus, making it difficult to flow down from the discharge pipe. The phenomenon of the water meniscus is more remarkable as the pipe has a smaller diameter, and in a pretreatment apparatus using a pipe with a smaller diameter, the self-weight quantitative measurement method is not an appropriate quantitative measurement from the viewpoint of reliability.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a self-weight falling type pretreatment device capable of performing highly reliable quantitative measurement in the pretreatment device.

[0007]

SUMMARY OF THE INVENTION A self-weight falling pretreatment apparatus of the present invention is an apparatus for performing pretreatment such as dilution when titrating or analyzing a liquid sample or a diluting liquid. This is a quantification device for quantifying, and urges a liquid to flow down at a fixed amount discharge port by opening and closing a fixed amount opening / closing valve in a short cycle.

[0008] The quantification means provided in the self-weight falling type pretreatment device of the present invention is a quantification tank having an inlet, an overflow outlet, and a quantification discharge port, and a quantification opening / closing valve for controlling the discharge of liquid from the quantification discharge port. The opening / closing operation of the fixed-quantity on-off valve includes a short-period opening / closing operation during one opening / closing operation, and the opening / closing operation releases a fixed amount of liquid in the fixed-quantity tank to quantify the liquid. Short-period opening and closing can also be configured by a plurality of opening and closing.

According to the self-weight falling type pretreatment device of the present invention,
When the liquid is injected into the fixed quantity tank from the inlet with the fixed quantity open / close valve closed, the injected liquid is stored in the fixed quantity tank without flowing out from the fixed quantity discharge port because the fixed quantity open / close valve is closed. As the liquid injection continues, the liquid exceeding the fixed amount is discharged from the overflow outlet. by this,
A fixed amount of liquid is stored between the fixed amount discharge port and the overflow discharge port in the fixed amount tank.

In this state, the opening / closing operation of the fixed-quantity on-off valve is performed. The fixed-quantity on-off valve provided in the self-weight falling type pretreatment device of the present invention opens and closes in a short cycle during one opening and closing operation. With the short-period opening and closing of the fixed-quantity on-off valve, a pulsation due to pressure fluctuation, vibration, or the like is applied to the liquid level near the fixed-quantity discharge port, and the flow resistance due to surface tension decreases. As a result, the flow of the fixed amount discharge port becomes good, the fixed amount liquid stored in the fixed amount tank can flow down reliably, and a highly reliable quantitative measurement can be performed.

In the embodiment of the present invention, the short-period opening / closing performed by the fixed-quantity on-off valve is performed at an initial stage of one opening / closing operation, whereby the flow resistance at the fixed-volume discharge port is reduced at the initial stage. Can be. Normally, the flow resistance of the liquid becomes low after the start of the flow, and the flow continues. Therefore, once the flow is started by opening and closing in a short cycle in the initial stage, the subsequent flow promotion operation can be made unnecessary.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic block diagram for explaining the configuration of the self-weight falling type pretreatment device of the present invention. 1 shows only a portion of the quantification device of the pretreatment device, and a device portion for performing pretreatment such as dilution performed when performing titration or analysis of another liquid sample or diluent. Is omitted.

In FIG. 1, a self-weight falling type pretreatment device 1 is shown.
Is provided with a quantitative measuring device including a quantitative tank 2 having an overflow discharge port 4 and a quantitative discharge port 5, injects a liquid into the quantitative tank 2 from an inlet 3, and stores the liquid. The liquid is discharged from the fixed amount discharge port 5. In the metering tank 2, the overflow outlet 4 is arranged at an upper position, and the lower end of the overflow outlet 4 forms a first water level 31. Further, the fixed-quantity discharge port 5 is disposed at a lower position, and the upper end of the fixed-quantity discharge port 5 forms a second water level 32. The fixed amount in the fixed amount tank 2 is set by the volume between the first water level 31 and the second water level 32. Therefore, the amount of the liquid to be quantified can be set by adjusting the water level difference by adjusting the installation positions of the overflow outlet 4 and the fixed amount outlet 5.

An overflow discharge pipe 10 is connected to the overflow discharge port 4 to discharge the overflowed liquid, and a fixed discharge pipe 11 is connected to the fixed discharge port 5 so that the fixed liquid in the fixed tank 2 can be discharged. Make a release. The release of the liquid from the fixed amount discharge port 5 can be controlled by opening and closing a fixed amount opening / closing valve 21 provided in the fixed amount discharge pipe 11.

Further, by forming the discharge port 6 below the fixed amount discharge port 5 and connecting the discharge pipe 12 to the discharge port 6, the liquid in the fixed amount tank 2 can be arbitrarily discharged. The discharge of the liquid from the discharge port 6 is performed by the discharge pipe 12.
Can be controlled by the opening / closing operation of the full-outlet opening / closing valve 22 provided in the above. Further, by providing the discharge port 6 at the lowermost position of the fixed quantity tank 2, all the liquid in the fixed quantity tank 2 can be discharged. The opening / closing operation of the fixed-quantity on-off valve 21 and the full-outlet on-off valve 22 is performed according to a sequence corresponding to the quantification process in a pretreatment process performed by the self-weight falling type pretreatment device, and is controlled by a sequencer or a control device. Is done.

FIG. 2 is a diagram for explaining an opening / closing control signal of the fixed amount opening / closing valve. FIG. 2A shows a control signal for controlling the opening and closing of the fixed-volume on-off valve, which is conventionally performed normally. After the closing signal, an open signal for a predetermined time T is output to open the fixed-off valve 21.
This is a control signal that causes the liquid in the fixed amount tank 2 to be released, and causes the closing operation of the fixed amount opening / closing valve 21 to be performed according to a subsequent closing signal.

When the fixed-quantity on-off valve 21 is closed, no liquid exists on the fixed-discharge tube 11 side from the fixed-quantity discharge port 5 and the liquid is filled with a gas such as air. Therefore, quantitative tank 2
The liquid in the container is pushed by the pressure of the gas in the fixed-quantity discharge tube 11 at the fixed-quantity discharge port 5, and the outflow to the fixed-quantity discharge tube 11 side is suppressed. When the fixed-volume on-off valve 21 is opened by the open signal as shown in FIG. 2A, the fixed-volume discharge pipe 11 communicates with the discharge side via the fixed-volume on-off valve 21, and the pressure in the fixed-volume discharge pipe 11 becomes the pressure on the discharge side. And equal pressure. At this time, when the surface tension generated at the fixed-quantity discharge port 5 is large, the flowing resistance increases, and the liquid in the fixed-quantity tank 2 stops in the fixed-quantity tank 2 without being discharged to the fixed-quantity discharge tube 11 side, and the accurate Quantitation becomes difficult.

On the other hand, FIG. 2 (b) shows an opening / closing control signal of the fixed quantity opening / closing valve of the fixed quantity apparatus provided in the self-weight falling type pretreatment device of the present invention. Is repeated to open and close the fixed-quantity on-off valve 21. Subsequently, an open signal for a predetermined time T2 is output to open the fixed-quantity on-off valve 21, thereby discharging the liquid in the fixed-quantity tank 2. Of the fixed quantity on-off valve 21
Is a control signal for performing the operation of closing the.

In a state where the fixed quantity on-off valve 21 is closed, FIG.
Similarly to (a), the liquid in the fixed amount tank 2 is pushed by the gas pressure in the fixed amount discharge tube 11 at the fixed amount discharge port 5, and the outflow to the fixed amount discharge tube 11 side is suppressed. When the opening / closing of the fixed-quantity on-off valve 21 is repeated by the short-cycle opening / closing signal shown in FIG. 2B, the fixed-quantity discharge pipe 11 repeats a state communicating with the discharge side via the fixed-quantity on-off valve 21 and a state blocked. That is, the pressure in the fixed amount discharge tube 11 fluctuates. Therefore, the pressure applied to the liquid at the fixed amount discharge port 5 also fluctuates according to the short-period opening / closing signal. In addition, the mechanical vibration generated by the short-period opening / closing operation of the fixed-quantity on-off valve 21 is caused by
The liquid is transmitted to the fixed amount discharge port 5 through 1 and vibrates the fixed amount discharge port 5 and the liquid in the fixed amount discharge port 5.

The pulsation such as pressure fluctuation and vibration at the fixed quantity discharge port 5 gives vibration to the liquid closing the fixed quantity discharge port 5. Therefore, even when the surface tension is large at the fixed amount discharge port 5, the flow resistance is reduced by the pulsation generated by the short-period opening / closing operation of the fixed amount opening / closing valve 21, and the liquid in the fixed amount tank 2 is reduced during the predetermined time T2. It is released to the fixed amount discharge tube 11 side. The predetermined time T1 for opening and closing in a short cycle is set in advance in accordance with surface tension generation conditions such as the diameter of the fixed-rate discharge tube 11 and the viscosity of the liquid, and the cycle and the number of times are set in accordance with the surface tension. It can be set arbitrarily. The predetermined time T2 during which the liquid is discharged is set to a time sufficient for discharging the amount of liquid discharged from the metering tank 2. Therefore, the total time T3 of the opening / closing operation is the sum of the predetermined time T1 and the predetermined time T2.

Next, the operation of the quantitative apparatus of the self-weight falling type pretreatment apparatus of the present invention will be described with reference to FIG. FIG.
(A) is a step of injecting a liquid into the fixed quantity tank 2, in which the liquid is injected into the fixed quantity tank 2 from the inlet 3 with the fixed quantity opening / closing valve 21 and the all-out opening / closing valve 22 closed (FIG. 3). (A) arrow). In the process of injecting the liquid, since the fixed amount opening / closing valve 21 is closed, the liquid does not flow into the fixed amount discharge pipe 11 from the fixed amount discharge port 5, and the liquid is stored beyond the second water level 32.

Next, in FIG. 3 (b), when the injection of the liquid continues and exceeds the first water level 31 of the metering tank 2, the liquid passes through the overflow discharge port 4 and overflow discharge pipe 1
It is discharged to the 0 side (arrow B in the figure). Therefore, the fixed amount tank 2
Is limited to the first water level 31 and the first water level 31 and the second
The liquid stored during the water level 32 is always quantitative. In addition, the diameter of the overflow discharge port 4 is set to a sufficient diameter that does not hinder the flow of the liquid due to surface tension.

After confirming the discharge of the liquid from the overflow outlet 4, the injection of the liquid is stopped. Thereafter, when the fixed-quantity on-off valve 21 is opened and closed by the short-period opening and closing of the opening and closing control signal, pulsation such as pressure fluctuation or vibration accompanying the opening and closing is transmitted to the fixed-quantity discharge port 5, the flow resistance is reduced, and The discharge of the liquid to the fixed discharge tube 11 side starts. When the discharge of the liquid starts, the liquid level in the quantitative tank 2 decreases as shown by the arrow in FIG. At this time, the all-outlet opening / closing valve 22 is in the closed state, the liquid is not discharged from the discharge port 6, and the liquid is discharged only from the fixed discharge port 5.

As shown in FIG. 3D, when the liquid level reaches the second water level 32 due to the discharge of the liquid from the fixed quantity discharge port 5, the discharge of the liquid from the fixed quantity discharge port 5 is stopped. As a result, the liquid stored in the first water level 31 to the second water level 32 in the fixed amount tank 2 is discharged to the fixed amount discharge pipe 11 through the fixed amount discharge port 5. Since the amount of the liquid discharged to the fixed discharge pipe 11 side is a fixed amount determined between the first water level 31 and the second water level 32, the discharged liquid is quantified.

FIGS. 3 (e) and 3 (f) show a process of discharging the liquid stored in the fixed amount tank 2 in total. FIG. 3 (e)
When the all-outlet opening / closing valve 22 is opened, the liquid stored in the fixed amount tank 2 starts to be discharged to the discharge pipe 12 through the discharge port 6, and after a predetermined time, as shown in FIG. All the liquid in the metering tank 2 is discharged outside. Fully open / close valve 22
The opening / closing control may be an opening / closing operation including short-period opening / closing as in the case of the fixed amount opening / closing valve 21. Usually, the outlet 6 for discharging all the liquid in the fixed amount tank 2 is provided at the bottom of the fixed amount tank 2. Since the stored liquid overcomes the surface tension and flows down, the operation can be performed only by opening and closing.

FIG. 4 is a schematic diagram for explaining an example of the configuration of a sampling device using the self-weight falling type pretreatment device of the present invention. The sampling device 40 is a device that samples and analyzes a liquid sample using an atomic absorption spectrometer 52 or an alkalinity meter 51, and performs pretreatment such as a dilution process before performing analysis with the atomic absorption spectrometer 52. In this pretreatment, the quantification of the liquid sample or the diluent is required, and in order to perform the quantification, the quantification devices 41, 42, and 43 of the self-weight falling type using the device of the present invention described above are used. Thereby, the self-weight falling pretreatment device can be formed with a simple configuration without using a device such as a syringe or a pump for driving the syringe.

[0027]

As described above, according to the self-weight falling type pretreatment device of the present invention, highly reliable quantitative measurement can be performed in the pretreatment device.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram for explaining a configuration of a self-weight falling type pretreatment device of the present invention.

FIG. 2 is a diagram for explaining an opening / closing control signal of a fixed-quantity on-off valve of the self-weight falling type pretreatment device of the present invention.

FIG. 3 is a view for explaining the operation of the quantitative device of the self-weight falling pretreatment device of the present invention.

FIG. 4 is a schematic diagram for explaining a configuration example of a sampling device using a self-weight falling pretreatment device of the present invention.

[Explanation of symbols]

1 ... gravity-flow type pretreatment device, 2 ... fixed amount tank, 3 ... injection port,
4 ... Overflow discharge port, 5 ... Quantitative discharge port, 6 ... Discharge port, 10 ... Overflow discharge pipe, 11 ... Quantitative discharge pipe,
12 ... discharge pipe, 21 ... fixed-quantity on-off valve, 22 ... full-outlet on-off valve,
31: first water level, 32: second water level, 40: sampling device, 41, 42, 43: quantification device.

Claims (1)

[Claims] 1. A fixed-quantity tank having an inlet, an overflow outlet, and a fixed-quantity discharge port, and a fixed-quantity on-off valve for controlling the release of liquid from the fixed-quantity discharge port. A self-weight falling type pretreatment apparatus comprising a short period opening / closing operation during opening / closing operation, and quantifying means for quantifying the liquid by discharging a certain amount of liquid in the quantification tank by the opening / closing operation. .