JPS6247071Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a sampling device for sampling a sample when analyzing a sample with a gas chromatograph, and in particular, a system that allows fluid to flow back against the sampling probe while sampling is not being performed. The present invention relates to a sampling device that is used as a sampling device.

Conventionally, in this type of sampling device, as shown in Fig. 1, a probe 12 is inserted into a process 11, and the gas or liquid sample collected from the probe 12 passes through a valve 13 and is passed through a separator 14 to remove unnecessary components such as tar. is removed and further supplied to the switching valve 16 through the filter 15. The switching valve 16 and sampling valve 17 are indicated by white circles "〇" in the figure.
and the black circle "●", and when the black circle "●" is switched, the switching valve 16
The sample supplied to the sample passes through the sampling valve 17, passes through the measuring device 19, and returns to the sampling valve 1.
7 and from there, the discharge pipe 23 passes through the switching valve 16.
is discharged. When the switching valve 16 and the sampling valve 17 are switched to the white circle "○", the sample taken into the meter 19 is passed through the sampling valve 17 by the carrier gas supplied to the sampling valve 17 through the pipe 18, and then the sample is passed through the pipe 18. 21 to a column in an analysis unit 22. At this time, the sample from the filter 15 is supplied to the discharge pipe 23 through the switching valve 16.

separator 14, filter 15, switching valve 16,
The sampling valve 17 is housed in a constant temperature bath 26. Further, a passage from the probe 12 to the constant temperature bath 26 is arranged in a heat-retaining steam line 27, and the heat-retaining steam from a pipe 28 is supplied to the steam line 27. Similarly, the pipe 21 from the constant temperature bath 26 to the analysis unit 22 is connected to the heat retention passage 2.
9 , and steam is supplied to the heat retention passage 29 through a pipe 31 .

Depending on the sample to be collected, the probe 12
may be easily clogged due to, for example, tar. For this reason, when a sample is not being sampled, fluid is caused to flow back into the probe 12. That is, the main backflow passage 32 is branched and connected on the probe 12 side near the valve 13 provided at the probe side inlet of the thermostatic chamber 26 . For example, steam is supplied to the main backflow passage 32 from a pipe 34 at a predetermined pressure through a control valve 33. When the introduction of the sample is stopped in this way, the control valve 3
3 was controlled to cause steam to flow back into the probe 12 through the main backflow passage 32, that is, to blow steam into the process 11 through the probe 12 to prevent the probe 12 from clogging. For example, when sampling a sample containing high boiling point components, tar, etc., such as when sampling gas at the outlet of an ethylene cracking furnace, there is a risk that the probe 12 may become clogged, and such clogging is prevented as described above. .

In this way, in the conventional sampling device, clogging of the probe is prevented, but the control valve 3
3 breaks down or the piping system of the main backflow passage 32 breaks down, that is, the main backflow system breaks down and the steam pressure drops below the specified value, steam will no longer flow back through the probe 12, or even if it flows back, it will not flow back. In some cases, the pressure was too weak to sufficiently prevent the probe from clogging.

The purpose of this invention is to reliably prevent clogging of the probe regardless of a failure of the main steam backflow system in a sampling device that prevents clogging by flowing steam back into the probe at times other than sampling. The object of the present invention is to provide a sampling device that provides a

According to this idea, an auxiliary backflow system is installed in parallel with the main backflow system for backflowing steam to the probe, and when the main backflow system becomes abnormal, it is detected.
This detection activates the auxiliary backflow system to backflow inert gas to the probe.

For example, as shown in FIG. 2 with the same reference numerals attached to parts corresponding to those in FIG. In this example, it is branched and connected to the main backflow passage 32 . An inert gas supply source 37 is connected to the other end of the auxiliary backflow passage to provide an auxiliary backflow system separate from the main backflow system.

Means are provided for detecting abnormalities in the main backflow system, such as the main backflow passageway 32 or the fluid source supplying fluid thereto. For example, a pressure gauge 38 is attached to the main backflow passage 32, and when the pressure of steam in the main backflow passage 32 falls below a predetermined value, it is detected that the main backflow system has become abnormal.

The auxiliary backflow system is driven by this abnormality detection.
For example, when the solenoid valve 39 is inserted into the auxiliary backflow passage 36 and the pressure gauge 38 detects that the pressure in the main backflow passage 32 has fallen below a predetermined value, the drive circuit 41 is driven by the detection output.
1 opens the solenoid valve 39. This allows the inert gas from the inert gas source 37 to flow into the auxiliary backflow passage 3.
6 into the probe 12 and the inert gas is blown into the process 11. In this case, for example, a valve is installed in the main backflow passage 32 between the connection point of the auxiliary backflow passage 36 and the main backflow passage 32 and the pressure gauge 38 so that the inert gas in the auxiliary backflow system is not supplied to the fluid source side of the main backflow system. 42 is inserted and valve 39 is opened, valve 42 is closed.

For example, when the pressure of the process 11 is P ₀ , the pressure of the steam for backflow is P ₁ , and the pressure of the main backflow passage 32 is P ₂ , the set value P _s of the pressure gauge 38 is greater than P ₀ and P ₁
is selected to be smaller than. When the pressure P ₂ in the main backflow passage 32 becomes equal to or less than the set value P _s when the control valve 33 is open, that is, when no sampling is being performed, the solenoid valve 39 is opened.

As mentioned above, according to the sampling device according to this invention, in the existing sampling device,
Clogging of the probe 12 can be completely prevented by simply adding a few things such as an auxiliary backflow passage, an abnormality detection means, and a solenoid valve.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional sampling device, and FIG. 2 is a block diagram showing an example of a sampling device according to this invention. 11...Process, 12...Probe, 16...
...Switching valve, 17...Sampling valve, 19...
...Measuring tube, 18...Carrier gas pipe, 22
...Analysis unit, 32...Main backflow passage, 33...
...Control valve, 34...Steam supply pipe for backflow,
36... Auxiliary backflow passage, 38... Pressure gauge as abnormality detection means, 37... Inert gas supply, 39...
... Solenoid valve, 41 ... Drive circuit.

Claims (1)

[Claims for Utility Model Registration] In a sampling device configured to cause steam to flow back against a probe inserted into a process except during sampling, an inert gas an auxiliary backflow passage as a separate route for backflowing the steam; an abnormality detection means for detecting when the steam pressure in the main backflow passage becomes less than a set value; A sampling device comprising: means for causing backflow to the probe;