JP3311829B2 - Auto sampler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an autosampler, and more particularly, to an autosampler for automatically taking a fixed amount of a sample liquid by using only a liquid pressure from a main pipe through which a liquid flows.

[0002]

2. Description of the Related Art In the fluid industry, when liquids of a plurality of liquid types are mixed at a predetermined ratio or when components of a predetermined liquid are analyzed, the mixing ratio of the mixed liquid is maintained properly, or a specified component is determined. 2. Description of the Related Art In order to analyze and test whether or not a liquid has a liquid, a sampler that collects a predetermined amount or a fixed amount of a sample liquid from a main pipe through which the liquid flows is known.

[0003] The type of liquid flowing in the main pipe in the process differs depending on the purpose and varies, and is a safe fluid that does not cause a danger such as explosion under normal environmental conditions, or an organic solvent or the like that has a danger of explosion. There is light oil. An actuator is used to collect a liquid sample liquid, and an air cylinder driven by air pressure is usually used as an actuator from the viewpoint of explosion protection for sampling a liquid having a risk of explosion. A conventional sampler is composed of a fixed amount cylinder, an air cylinder, and a sample container, and is disposed in principle near the main pipe to reduce a sample liquid remaining in a conduit connecting the sampler and the main pipe, thereby reducing a sample error. The occurrence of is reduced. The rod of the air cylinder is joined to the piston of the metering cylinder, and the sample liquid is collected in the metering cylinder by the hydraulic pressure of the main pipe or a separately installed pump. Discharged and collected in a sample container. If necessary, a sampling operation is performed several times to collect a predetermined amount of the sample liquid in the sample container.

However, the sampler is disposed near the predetermined main pipe as described above, and the conventional sampler has an air cylinder and requires an air pressure source. If it is far from the source, a new air line must be installed, and there may be no air source from the beginning. If a new sampler is to be installed in such a place, there is a problem that the cost of equipment for driving the sampler is increased.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and switches an on-off valve using a force generated by applying pressure in a main pipe to a piston of a cylinder having a different sectional area as a driving source of a sampler. It is an object of the present invention to provide an autosampler that can automatically collect a sample liquid.

[0006]

To achieve the above object, the present invention provides a sampler for collecting a constant sample liquid at predetermined intervals from a main pipe through which a liquid flows, and a large-diameter cylinder and an opening coaxially formed on one end surface of the large-diameter cylinder. A small-diameter cylinder, and a piston which is movably inserted into the large-diameter cylinder and the small-diameter cylinder so as to be movable in a liquid-tight manner and is connected by a piston rod, and in the section sandwiched by each piston, the large-diameter cylinder or A metering drive unit having at least a portion of a pipe wall of a small-diameter cylinder with a ventilation hole, a communication pipe communicating the other end of the small-diameter cylinder with a main pipe, and the other end face of the large-diameter cylinder and the main pipe; A first on-off valve disposed between
A second on-off valve disposed on the other end surface of the large-diameter cylinder and having the other end open to the atmosphere, and on-off valve driving means for alternately opening and closing the first and second on-off valves. It is assumed that. Hereinafter, a description will be given based on examples of the present invention.

FIG. 1 is a block diagram for explaining an autosampler according to the present invention. In the figure, 1 is a main pipe, 2 is a metering drive unit, 3 is a large-diameter cylinder, 4 is a small-diameter cylinder, 5
Is a large piston, 6 is a small piston, 7 is a piston rod,
8 is a vent, 9 is a first on-off valve, 10 is a second on-off valve, 1
1, 12 are valves, 13 is a sample container, 14, 15, 16
Is a conduit, 17 is a timer, 18 is a lead wire, 19 is a small cylinder chamber, 20 is an empty chamber, and 21 is a metering drive chamber.

A sample liquid flows in the main pipe 1 in the direction of arrow Q. The metering drive unit 2 includes a large-diameter cylinder 3, a small-diameter cylinder 4 that opens coaxially on one end surface 3 b of the large-diameter cylinder 3, and a large piston 5 that is slidably housed in the large-diameter cylinder 3 in a liquid-tight manner. A small piston slidably housed in a small-diameter cylinder 4 in a liquid-tight manner, and a piston rod 7 integrally connected to a small piston 6 in the small-diameter cylinder 4. Further, a ventilation hole 8 is opened between the large piston 5 and the small piston 6 on the tube wall of the large-diameter cylinder 3 or the small-diameter cylinder 4, that is, at a position corresponding to the section of the piston rod 7. At this time, the position of the ventilation hole 8 is selected so that the large piston 5 or the small piston 6 does not move and close the ventilation hole 8.

The other end 4a of the small-diameter cylinder communicates with the main pipe 1 through a valve 12 through a conduit 14, and a small cylinder chamber 19 is filled with liquid. Further, a conduit 15 is connected to the other end surface 3a of the large-diameter cylinder 3, and a first on-off valve 9 and a second on-off valve 10, which are, for example, electromagnetic valves, are branched and connected to the conduit 15. Further, the first on-off valve 9 is a valve 11
The second on-off valve 10 is open to the sampling container 13 via the conduit 16.

The first and second on-off valves 9 and 10 are controlled to open and close by a timer 17 via a conductor 18, for example, when one of the first on-off valves 9 opens, the other second on-off valve 10 closes. When the first on-off valve 9 is closed, the second on-off valve 10 is opened.

Next, the operation of the thus constructed autosampler of the present invention will be described. First, in use, valve 1
Valves 1 and 12 are opened, the small-diameter cylinder 4 and the main pipe 1 are in communication with each other, and hydraulic pressure is acting on the small cylinder chamber 19. (1) The first on-off valve 9 is closed and the second on-off valve 10 is open. Vacancy 20 sandwiched between large piston 5 and small piston 6
Is opened to the atmosphere through the vent hole 8, and the metering drive chamber 21 is also opened to the atmosphere through the second on-off valve 10. Therefore, the hydraulic pressure in the main pipe 1 acts on the right end face of the small piston 6, The large piston 5 together with the small piston 6 has the end face 3 in the (-X) direction.
Move until it touches a.

(2) The first on-off valve 9 is open and the second on-off valve 1
0 is the valve closed state. The operation of the timer 17 causes the first on-off valve 9
Is opened and the second on-off valve 10 is closed, the large piston 5
And the small piston 6 are acted upon by the hydraulic pressures of the main pipe 1 opposite to each other. However, due to the area difference between the large and small pistons 5, 6, the large piston overcomes and advances in the (+ X) direction, and moves until the small piston 6 contacts the end area 4a. As a result,
A sample liquid is stored in the metering drive chamber 21.

When the first on-off valve 9 is closed and the second on-off valve 10 is opened by the operation of the timer 17, the pressure in the metering drive chamber 21 becomes atmospheric pressure, and the pressure in the small cylinder 19 rises. Since it is high, the small piston 6 moves in the (-X) direction, and the sample liquid in the metering drive chamber 21 is discharged into the sample container 13 via the second on-off valve 10. In this state (1),
By continuously operating (2) a plurality of times, a predetermined volume of the sample liquid is stored in the sample container 13.

In the case of the above (1), at the time of the first sampling cycle, since the sample liquid from the previous sampling remains in the conduit 15, it is not contained in the sample container 13 as necessary, It is returned to the main pipe 1 as a cut or discharged into a pit (not shown).

In the above description, the sampling cycle is performed according to the time setting of the timer 17,
Set to a predetermined flow rate of the liquid flowing through, for example, to a batch counter, input a flow signal transmitted from the flow meter,
When the set amount is reached, a method of switching the constant flow rate according to the flow rate setting for switching the first and second on-off valves 9 and 10 may be used.

[0016]

As is clear from the above description, according to the present invention, no driving energy other than the power supply for driving the solenoid valve is required, and the sampling liquid is collected at regular intervals or at constant flow rates using only hydraulic pressure as power. Therefore, inexpensive sampling can be performed even in an area without an air source.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining an autosampler according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main pipe, 2 ... Measuring drive part, 3 ... Large diameter cylinder, 4 ...
Small bore cylinder, 5 large piston, 6 small piston, 7
... Piston rod, 8 ... Vent hole, 9 ... First open / close valve, 10
... second on-off valves, 11, 12 ... valves, 13 ... sample containers,
14, 15, 16 ... conduit, 17 ... timer, 18 ... conductor,
19: small cylinder chamber, 20: empty chamber, 21: metering drive chamber.

Claims (1)

(57) [Claims] 1. A sampler for collecting a constant sample liquid at predetermined intervals from a main pipe through which a liquid flows, a large-diameter cylinder, a small-diameter cylinder coaxially opened at one end surface of the large-diameter cylinder, and a large-diameter cylinder. And a piston which is movably inserted into a small-diameter cylinder and is connected by a piston rod, and at least a part of the pipe wall of the large-diameter cylinder or the small-diameter cylinder in a section sandwiched between the pistons. Metering drive unit having a vent hole formed therein, a communication pipe communicating the other end of the small-diameter cylinder with the main pipe, and a first opening / closing disposed between the other end face of the large-diameter cylinder and the main pipe. A second on-off valve disposed on the other end surface of the large-diameter cylinder and having the other end open to the atmosphere;
An autosampler comprising an on-off valve driving means for alternately opening and closing an on-off valve and a second on-off valve.