JPS5830205Y2 - Liquid quantitative supply device - Google Patents

Description

[Detailed Description of the Invention] The present invention mainly relates to an apparatus for quantitatively supplying liquids such as reagents used in chemical analysis.

In an automated chemical analysis device, a device is required to supply liquids such as reagents and washing water in fixed amounts.

For example, there is a device that uses a metering pump to aspirate and dispense a fixed amount of reagent, but since it requires the same number of pumps as the types of reagents, the more types there are, the more expensive it is, and the larger the installation space. There is a drawback.

The second device is one in which a discharge port is provided at the bottom of a reagent container via a valve, and a fixed amount of reagent is discharged by opening the valve for a certain period of time.

The disadvantage of this device is that the discharge pressure depends on the liquid pressure depending on the depth of the reagent remaining in the container, so the discharge flow rate changes depending on the amount of reagent remaining, so even if the valve is opened for a certain period of time, a fixed amount will not be discharged. .

In order to improve this drawback, there is a device that maintains the liquid pressure at the liquid discharge port at atmospheric pressure, keeps the discharge pressure constant regardless of the remaining amount of reagent, and supplies a fixed amount of liquid.

However, the disadvantage of this device is that the reagent is discharged by falling due to gravity, so the reagent container must be placed higher than the discharge port, which makes it inconvenient to check the remaining amount of reagent and replenish it. There is also a risk of doing so.

Another drawback is that as the amount of reagent decreases, outside air is blown into the reagent, causing deterioration of the quality of the reagent.

The object of the present invention is to provide a liquid metering device which eliminates the drawbacks of the conventional devices mentioned above.

That is, a closed container for holding the liquid to be supplied, a conduit whose both ends communicate with the closed container and which is arranged so that the liquid in the closed container flows from one end through a valve, and a valve connected to the conduit. and a discharge port communicating with the conduit through the conduit, and by blowing gas into the sealed container, only a fixed amount of liquid accumulated in the conduit is discharged from the discharge port, thereby reducing the amount of liquid in the container. It is an object of the present invention to provide a liquid quantitative supply device capable of quantitatively supplying a liquid regardless of the amount.

An embodiment of the present invention will be described below with reference to the drawings.

The figure is a schematic configuration diagram showing an embodiment of the present invention, in which 1 is a sealed container for containing the liquid to be supplied, 2 is a conduit communicating with the sealed container 1, and a part 2a of the pipe is for storing a predetermined amount of liquid. A bundle of conduits is a length that allows for

3 is a three-way switching valve using, for example, a three-way solenoid valve, and normally the sealed container 1 and the conduit 2 are electrically connected, and the conduit 2 is turned on when energized.
is cut off from the closed container 1, and at the same time communicates with the conduit 4 having the discharge port 4a.

The closed container 1 is connected via a normally closed valve 5, for example a solenoid valve, and a conduit 6 to a source of high pressure gas, not shown.

Preferably, an inert gas (eg nitrogen gas) is used as the high pressure gas source.

Reference numeral 7 denotes a liquid supply port, which has a seal plug 8 (for example, a screw lid with a gasket) that can withstand gas pressure.

Next, the operation of the present invention with the above configuration will be explained.

Open the cap 8 and replenish the liquid into the sealed container 1.

At this time, the liquid level should be lower than the upper open end of the conduit 2.

After replenishing, close the stopper 8.

The liquid also enters the conduit 2, and the liquid level in the conduit 2 reaches the closed container 1.
equal to the liquid level within.

Next, when the three-way switching valve 3 and the valve 5 are operated, the conduit 2 is cut off from the closed container 1, and at the same time, the liquid accumulated in the conduit 2 is forced out by high pressure gas and is discharged from the discharge port 4a via the conduit 4. .

Since the liquid is forced out under the pressure of high-pressure gas, the discharge port 4a
can be higher than the closed container 1.

Therefore, the installation location of the closed container 1 can be selected as appropriate.

To be precise, there is an error in the amount of liquid accumulated in the conduit 2 due to changes in the liquid level.

For example, if conduit 2 is a polytetrafluoroethylene tube with an inner diameter of 2 mm, the maximum depth of sealed container 1 is 10 cm, and lQml is selected as the quantitative value, the conduit length is 3.2 m and the error is 3.1%. becomes.

In ordinary chemical analysis, this level of error in the amount of liquid supplied is fully acceptable.

In this embodiment, if a polytetrafluoroethylene tube with an inner diameter of 1 mm is used as the conduit 2, this error is reduced to 0.79%.

However, it is not practical because a 12.7 m conduit is required to store 10 m1.

In such a case, it is preferable to make only a portion 2a of the conduit thicker and shorter.

By appropriately selecting the inner diameter of the conduit 2 in this way, the required quantitative value and accuracy can be achieved.

By configuring the present invention as described above, the following effects can be obtained.

In other words, since the liquid is discharged using high-pressure gas, it is possible to supply a fixed amount regardless of the amount of liquid in the container, and it is also possible to supply to high places.There is no residual liquid in the discharge pipe, so there is no possibility of air oxidation, etc. The liquid near the discharge port may change in quality.
No problems such as sticking and clogging occur.

Furthermore, since the upper open end of the conduit that stores a predetermined amount of liquid is communicated with the closed container, an amount of gas equal to the volume reduced by flowing out of the closed container is replenished from the upper open end, so that the outside There is no need to replenish air.

Therefore, the liquid can be isolated from air.

If an inert gas (e.g. nitrogen gas) is used as the high pressure gas,
It is possible to prevent deterioration of liquid due to air oxidation, etc.

In addition, since the configuration is simple, it does not become expensive even if the number of devices increases.
Does not take up a large installation space.

Furthermore, since the container does not need to be installed at a high place, it is easy to replenish the liquid and check the remaining amount, and there is no need to worry about it falling.

It is clear that the constant supply of liquid can be automated by configuring each valve with a solenoid valve.

[Brief explanation of drawings]

The figure is a schematic configuration diagram showing an embodiment of the present invention. 1... Airtight container, 2... Conduit, 3...
...Three-way switching valve, 4゜6...Conduit, 5...
...Valve, 7...Liquid supply port, 8...
・Tightly sealed.

Claims (1)

[Scope of utility model registration request] A closed container for containing the liquid to be supplied, a three-way switching valve having a first open end connected to the closed container, and the liquid in the closed container flowing into the closed container from one end connected to the second open end of the valve. a conduit having one end connected to the third open end of the valve and the other end being open and serving as a discharge port; 1. A liquid quantitative supply device characterized by comprising a conduit having a valve for blowing gas.