JPS5826371Y2 - liquid sampling device - Google Patents

Description

[Detailed description of the invention] This invention relates to a liquid sampling device used for water quality testing in, for example, sewage treatment plants, and in particular, it is easy to maintain by omitting a head tank for applying head pressure to the sampling device. It is an object of the present invention to provide a liquid sampling device that can prevent suspended matter contained in a sample liquid from stagnation and can extract a sample liquid with good representativeness.

One example of a liquid sampling device is one that uses a cylinder and a piston to collect a fixed amount of sample liquid and supplies it to an inspection device.

Since the sample liquid must be handled even if it is heavily contaminated, the inner wall of the sample collection cylinder is resistant to dirt.

For this reason, if the circumferential surface of the piston is brought into contact with the inner wall surface of the cylinder to maintain airtightness therebetween, it is difficult to maintain airtightness therebetween.

Therefore, generally, a rubber pellofram is interposed between the cylinder and the piston to maintain airtightness between the cylinder and the piston, thereby eliminating the need for the piston's curved surface to directly contact the inner wall of the cylinder.

When using a bellofram in this way, care must be taken to prevent the bellofram from being deformed both when applying pressure in one direction to the bellofram and sucking the sample liquid into the cylinder, and when discharging the sample liquid from the cylinder.

For example, if the configuration is such that negative pressure is applied to the velofram when sucking in a sample liquid, and positive pressure is applied when discharging the sample liquid, the velofram will expand outward and contract inward each time it is aspirated and dispensed, causing it to collapse. It has the disadvantage that it tends to cause scratches, which reduces its durability and significantly shortens the life of the velofram.

For this reason, in the past, when a head tank was installed, positive pressure was applied to the bellofram by the water head pressure of the head tank when sucking the sample liquid into the cylinder, and when discharging the sample liquid from the cylinder, the discharge pipe was connected to the water head position of the head tank. The discharge operation is performed with a positive pressure approximately equal to the head pressure of the head tank being applied to the verofram.

FIG. 1 shows a conventional liquid sampling device.

In the figure, 1 indicates a head tank, and 2 indicates a sample collection device.

That is, here, a case is shown in which a sample collection cylinder is used as the sample collection device.

3 is a piston that constitutes a part of this collection device; 4 is a bellofram installed between the cylinder 2 and the piston 3;
5 indicates a water quality testing device.

That is, a sample liquid is pumped up into the head tank 1 by a pump 7 from a channel 6 through which the sample liquid flows.

A weir 8 is provided in the head tank 1, and most of the pumped sample liquid is returned to the flow path 6 over the weir 8.

In this way, a certain amount of new sample liquid is always stored in the head tank 1.

A collection tube 9 is led out from near the bottom of the head tank 1, and is communicated with a sample inlet 11 of the cylinder 2 through a valve 10.

The uppermost position of the piston 3 that moves up and down within the cylinder 2 is selected to be equal to or lower than the water head position of the head tank 1.

Therefore, when the valve 10 is opened, the head pressure of the head tank 1 is applied to the cylinder 2, and the bellofram 4 is held in an outwardly expanded state even when the piston 3 reaches the uppermost position. A sample discharge port 12 is provided, and a sample discharge pipe 14 is attached to this discharge port via a valve 13.

The discharge pipe 14 is raised to approximately the same height as the water head position of the head tank 1 and connected to the inspection device 5.

By lifting the discharge pipe 14 to almost the same height as the water head position of the head tank 1 in this way, the valve 10 is closed and the valve 13 is closed.
Even if the cylinder 2 is opened, a pressure approximately equal to the head pressure of the head tank 1 is applied to the cylinder 2, and the bellofram 4 is held in an outwardly expanded state, and while maintaining this state, the sample liquid is discharged from the cylinder 2 and the inspection device 5 The sample liquid can be sent to the cylinder 2 and the bellofram 4 can be protected.
The head tank 1 is used to apply positive pressure to the verofram 4 when sucking the sample liquid.

However, the sample liquid often contains a large amount of floating matter, and there is a risk that this floating matter will stay on the bottom surface of the head tank 1 and gradually accumulate.

When suspended matter is deposited on the bottom surface of the head tank 1, the deposit is sometimes peeled off, resulting in a drawback that the representativeness of the sample liquid collected in the cylinder 2 is significantly impaired.

For this reason, the head tank 1 must be periodically cleaned to remove deposits, which also has the disadvantage of making maintenance troublesome.

The purpose of this invention is to provide a liquid sampling device that omits the head tank without losing the ability to apply positive pressure to the sampling device, making maintenance easier, and without compromising the representativeness of the sample liquid. be.

In this invention, the folded part of the water intake pipe formed by folding it back into a substantially U-shape is positioned upward, one end of which is inserted into the sample liquid, and the sample liquid is pumped from the inserted end toward the folded part by a pump. The sample liquid is returned to the sample liquid flow path from the other end of the body side, and a large amount of sample liquid is pumped through the intake pipe which is folded back in a U-shape. A hole is formed to open to atmospheric pressure, and the hole is formed to obtain a water head pressure between the folded part and the pump, and an appropriate amount of the water head pressure is applied to the sample collection device.

Therefore, according to this invention, since a large amount of the sample liquid is passed through the U-shaped water intake pipe, suspended matter contained in the sample liquid does not accumulate in the water intake pipe, which facilitates maintenance and reduces representativeness. It is possible to obtain a liquid sampling device without

An embodiment of this invention will be described in detail below with reference to the drawings.

FIG. 2 shows an embodiment of this invention.

In FIG. 2, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and redundant explanation thereof will be omitted; however, in this invention, a water intake pipe 15 folded back into a substantially U-shape is used in place of the head tank. .

In other words, the intake pipe 15 folded back into a U-shape has a folded part 15a.
is positioned above, and the free end of one leg 15b is inserted into the sample liquid flowing through the flow path 6.

A pump 7 is installed in the middle of the leg portion 15b into which one end is inserted, and the pump 7 pumps up the sample liquid flowing through the channel 6 toward the folded portion 15a.

The pumped sample liquid is returned to the channel 6 through the other leg 15c.

At the same time, a hole 16 is formed above the folded portion 15a, and the inside of the water intake pipe 15 is opened to atmospheric pressure through this hole 16.

By forming the hole 16, a water head pressure proportional to the head difference between the pump 7 and the water head position 17 can be applied to the position of the pump 7 on the leg portion 15b side.

Therefore, by connecting the sampling tube 9 communicating with the cylinder 2 to an appropriate position of the leg 15b, the water head position 17 and the sampling tube 9 can be adjusted.
A head pressure proportional to the head of the connecting position can be applied to the cylinder 2.

. Therefore, according to this invention, by appropriately selecting the connecting position of the water intake pipe 15 to the leg 15b, the water head pressure applied to the cylinder 2 can be set arbitrarily, and the water head pressure conventionally applied by the head tank can be changed into a U-shape. It can be provided by the water intake pipe 15.

However, according to this invention, the sample liquid is in the U-shaped water intake pipe 15.
Since the sample liquid only passes through the cylinder 2, there is no accumulation of suspended matter contained in the sample liquid.Therefore, there is no possibility that suspended matter will accumulate and the representativeness of the sample liquid collected in cylinder 2 will be impaired. It is possible to obtain a liquid sample collection device which is easy to use and does not impair the representativeness of the sample liquid, and the results are of great practical use.

In addition, in the above description, since the amount pumped by the pump 7 is large, the hole 16
If the sample liquid is spouted out, a side channel 18 is inserted between the legs 15b and 15c as shown by the dotted line in FIG.
may be provided.

Alternatively, a tube may be connected to the hole 16 and extend upwardly.

[Brief explanation of drawings]

FIG. 1 is a sectional view for explaining a conventional liquid sample collection device, and FIG. 2 is a sectional view showing an embodiment of this invention. 2...Cylinder as a sample collection device, 7
...Pump, 9...Collection tube, 15...
... Water intake pipe, 15a ... Turned part, 15b,
15c... Legs.

Claims (1)

[Scope of utility model registration request] A water intake pipe that is folded back into a U-shape, with the folded part facing upward, and the free end of at least one leg is inserted into the sample liquid; a pump that is attached to the leg on the side where the free end is inserted and pumps up the sample liquid toward the folded part; a hole that is formed above the folded part to open the inside of the water intake pipe to atmospheric pressure; and a collection tube for taking out a sample liquid from between the folded part and the folded part.