JPS6323078A - Method of detecting operating condition of valve - Google Patents

Abstract

PURPOSE:To rapidly judge whether a valve is normally operated or not, by operating a valve with the use of fluid pressure to open and close a fluid passage and by detecting the operation of the valve at that time with the use of a sensor. CONSTITUTION:Pressurized air is fed into an air system passage through a pressure reducing valve 21 to change over or open and close fluid passages. A recorder 28 records variations in pressure of air fed into an actuating valve 1 and the operating condition of a rack 16a of the valve. Accordingly, the operating condition of the valve is continuously recorded to judge whether the valve is normally operated or not.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for detecting the operating status of various valves, and in particular, to a method for detecting the operating status of a flow path switching valve used for processes such as chromatography in a chemical factory. This invention relates to a method for detecting the operating status of a valve suitable for detecting.

[Conventional technology] In chemical factories, etc., in order to analyze all the components of a process gas, a sample is adsorbed on one end of a stationary phase uniformly filled with adsorbent, and a liquid or gas is passed through as a mobile phase to detect the fractional adsorption phenomenon. Chromatography is used to separate a mixture of liquids and gases between a stationary phase and a mobile phase. Since this chromatography requires periodic analysis of samples at short intervals (for example, 10 minute intervals), the column must be backwashed periodically to clean it, and ffi substances must be discharged. There is.

That is, the sample (hydrocarbon) is
is passed through the column (#1), and the aliphatic hydrocarbon only column (#1) is passed through the column (#1).
#3) to analyze aliphatic hydrocarbons more precisely. In addition, if aromatic hydrocarbons (heavy components) are passed through the column at this time, the column will become clogged, so the flow path is switched to backwash or discharge it.

In the flow path diagram of FIG. 4, 100 is a sample valve, 2
00 and 300 are backflush valves, 400 is column switch valve, #l is first column, #2
is the second column and #3 is the third column. The following flow path is formed during sample analysis, backwashing, and discharge.

○ During sample analysis ■ (carrier gas) 201 → 202 → 101 → 10
2 → Column #1 → 304 → 303 → 401 → 402-Column #3 → Detector ■ (carrier gas) 301 →
302 → Column #2 → 204 → 203 → Vent ■ (carrier gas) 403 → 404 → Vent During sample analysis (after total 1) Sample valve 100 is rotated 90 degrees clockwise from the state of ■ above. (carrier gas) 201→202→103→104
→ Column #l → 304 → 303 → 401 → 402 - Column # 3 groaning detector ○ During backwash ■ (carrier gas) 301 → 304 → Column # 1 → 1
02 → 101 → 202 → 203 → Vent ■ (carrier gas) 201 → 204 → Column #2 → 3
02 → 303 → 401 → 402 → Column #3 → Detector ■ (carrier gas) 403 → 404 → Vent ○ When discharging ■ (carrier gas) 301 → 304 groaning column #1-
102 → 101 → 202 → 203 → Vent ■ (carrier gas) 201 → 204 → Column #2 → 3
02 → 303 401 → 404 → Vent (carrier gas) 403 → 402 → Column #3 → Detector On the other hand, the sample valve 100 mentioned above. Backflush valve 200.300 and column switch valve 4
00 is required to operate smoothly in order to perform 1 analysis with high precision. Therefore, it is necessary to detect the operating status of the valve in order to determine whether the valve is operating properly.

Conventionally, when detecting the operating status of a flow path switching valve used in process gas chromatography, etc., the spring section of the valve is pushed up with a metal rod to operate the rack section, etc.; The inspectors were making intuitive judgments as to whether there was a catch or not, or whether there was an insufficient stroke.

[Problems to be solved] In this way, the operating status of this type of valve is detected by the inspector's senses, so there may be individual differences due to inspector experience, or even if the same inspector There were variations due to this, which caused erroneous judgments.

The present invention has been developed in view of the above-mentioned problems.By detecting the operation of the valve by pressurized air with a sensor, it is possible to quantitatively determine in advance whether the valve has been assembled incorrectly or whether there are any defective parts. The purpose of the present invention is to provide a method for detecting the operating status of a valve, which is capable of predicting valve failure and also detecting the operating status of the valve actually in use.

[Means for solving problems] The method of detecting the operating status of a valve according to the present invention is as follows.

This method was developed in view of the above problems, and is a method in which a valve is actuated by FR or body pressure to switch or open/close a flow path, and the actuation of the valve at this time is detected by a sensor. The present invention is particularly suitable as a method for detecting the operating state of a flow path switching valve that is operated by the rotation of a pinion meshed with a rack that reciprocates due to fluid pressure. Preferably, the amount of movement of the valve is detected by a sensor, and the operating status of the valve is detected.

[Example] An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a valve J! for carrying out the method of the present invention. Figure 2 is an exploded perspective view of the device for detecting the operating status of the valve shown in Figure 1. This is a consultative map. First, the valve and the detection device will be explained based on these drawings.

In the drawing, 10 is a valve. Reference numeral 11 denotes a valve body, which is provided with a lid-shaped stopper lla that can be freely rotated at its upper part, and supports a cylindrical valve body 12 in a horizontal direction so as to be rotatable. The outer peripheral surface of the valve body 12 has a pinion 12 in the center.
A is provided, and a gland 13 is attached to both ends protruding from the side surface of the valve body 11 through a valve seat 12b so as to be relatively rotatable. Therefore, when the valve body 12 rotates, the valve seat 12b also rotates, changing the connection state of the ports 13b of the plurality of pipes 13a led to the gland 13, and changing the flow path ν1.

14 is a cylinder fixed to the lower part of the valve body 11, and 15 is an operating valve fixed to the lower part of the cylinder 14.

16 is an operating member, with an upper part.

Pinion 1 of the valve body 12 located inside the valve body 11
The rack 16a meshes with the cylinder 2a, and the middle part is the cylinder 1.
4, and the lower part is the operating valve 15.
The piston 16c is fixed to the bellows 7 ram 15a. A spring 17 is wound around a rod 16b within the cylinder 14, and constantly pushes the actuating member 16 downward. Therefore, when pressurized air is sent into the operating valve 15, the operating member 16 rises against the elastic force of the spring 17, rotates the valve body 12 that is engaged with the rack 15a, and switches the flow path. As a result, different flow paths can be formed depending on whether pressurized air is not supplied to the single-operation valve 15 or when pressurized air is supplied. 25 is a sensor described later.

Next, an example of a valve operating state detection device shown in FIG. 2 will be described.

Reference numeral 21 designates a pressure reducing valve provided in the air system path that sends pressurized air to the operating valve 15 of the valve lO, z2 also represents a solenoid valve, 23 represents a throttle valve, and 24 measures the air pressure supplied to the operating valve 15. It is a pneumatic pressure transmitter that converts into electrical signals. The sensor 25 is, for example, a high-frequency emitting magnetic sensor (eddy current position sensor) that is attached to the upper part of the valve body 11 after removing the stopper lla. This sensor 25 uses an excavation coil of one oscillation circuit as a detection head, and this oscillation coil is connected to a rack 16a made of a metal body.
When approached, eddy currents flow through the metal body and create a magnetic field, which acts on the oscillation coil and changes its impedance. Therefore, by converting the change in impedance caused by the movement of the rack 16a into an electrical signal using a positive feedback method or the like, it is possible to generate an output with good linearity corresponding to the amount of movement of the sear 7a 16a. 25
This is an oscillation/amplification circuit.

A control device 27 issues sequential commands to the solenoid valve 22 and the oscillation a amplifier circuit 26 in a predetermined order.

A recorder 28 records changes in the pressurized air supplied to the valve 10 based on the signal from the air pressure transmitter 24, and also records the operating status of the rack 16a based on the signal from the sensor 25. Record the amount of movement: a).

A method according to an embodiment of the present invention using such a valve operating state detection device is carried out according to the following procedure.

(1) Attach the valve IO to the operating state detection device and attach the sensor 25 to the upper part of the valve body 11.

(2) Pressurized air (3 kg/cm2
G or more) to the air system path, and turn on the power to the detection station.

(3) The solenoid valve 22 opens according to a command from the control device 27!
, pressurized air passes through the throttle valve 23 to the operating valve 1 of the valve lO.
5 and the air pressure transmitter 24, which causes the actuating member 16 to rise.

When the distance between the rack 16a and the sensor 25 changes slowly (the gap becomes narrower), the change in the pressure of the air supplied to the operating valve 15 and the operating status of the rack 16a, that is, the valve, are detected by air pressure transmitters. 24 and the signals from the oscillation/amplification circuit 26 are recorded by the recorder 28.

(4) Next, the solenoid valve 2
2 is closed, and the pressurized air supplied to the operating valve 15 and the air pressure transmitter 24 is gradually released. Made by this! The h member 16 is lowered and the distance between the rack lea and the sensor 25 slowly changes (the gap becomes wider). The recorder 28 records the change in air pressure at this time and the operating status of the rack 16a, that is, the valve.

(5) Repeat steps (3) and (4) above.

The operating status of the valve is continuously recorded and recorded in this record. !
Determine whether the valve is in good working condition based on the results.

Although it is recorded in a smooth state as shown in Figure 3 (L),
A valve that is not working properly? For example, Figure 3 (b
) is recorded when there are insufficient strokes.

In this way, according to the method of this embodiment, the operating status of the valve is clearly recorded on the recorder, so that it is possible to quickly and accurately judge whether the valve is good or bad just by looking at the recorded results. Furthermore, if the valve is defective, the operating status corresponding to the defective location is recorded, so it is possible to determine which location of the valve is defective just by looking at the recorded results. Furthermore, since failure of the valve can be predicted, it is possible to prevent the failure from occurring.

Note that the present invention is not limited to the above embodiments,
For example, it also includes variations such as linear.

■ When detecting the operating status of a switching valve that performs switching operation by means other than a rack and pinion.

■ When detecting the operating status of various valves other than switching valves used in process gas Φ chromatography, etc.

■ When detecting the operating status of a valve operated by a fluid other than air.

[Phase]) When detecting the operating status of the valve using a detection device other than the above-mentioned configuration (for example, changing the !i type of the sensor or using the recorder as the display device 2, etc.).

■ When a sensor is permanently attached to a valve to detect the operating status of the valve actually in use.

[Effects of the Invention] As described above, according to the method for detecting the operating status of a valve according to the present invention, it is possible to quickly and accurately determine whether a valve is good or bad.

[Brief explanation of the drawing]

FIG. 1 is a lower partially exploded perspective view of an example of a valve for carrying out the method of the present invention, FIG. 2 is a schematic diagram of a device for detecting the operating status of the valve shown in FIG. 1, and FIG. 3(a). (b) is a graph showing an example of recorded results, and FIG. 4 shows a flow path diagram of chromatography using a switching valve.

Claims (5)

[Claims] (1) A method for detecting the operating status of a valve, characterized in that the valve is operated by fluid pressure to switch or open/close a flow path, and the operation of the valve at this time is detected by a sensor. (2) The method for detecting the operating status of a valve according to claim 1, wherein the valve is a flow path switching valve operated by rotation of a pinion meshed with a rack that reciprocates due to fluid pressure. . (3) Claim 2, characterized in that the operating status of the valve is detected by the amount of movement of the reciprocating rack.
Detection method of valve operating status described in section. (4) Claim 1, characterized in that the sensor detects the operation of the valve continuously and while recording and displaying it.
, the method for detecting the operating status of a valve according to item 2 or 3. (5) A method for detecting operating status of a valve according to claim 1, 2, 3 or 4, wherein the fluid pressure is air pressure.