JP2001336957A - Chemical resisting sensor system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical resisting sensor system having good chemical resistance and hardly causing troubles such as corrosion. SOLUTION: This chemical resisting sensor system 10 is provided with a sensor main body 12, an exterior body 14 for air-tightly covering the sensor main body 12, a sensor leading-out conductor 16 penetrating the exterior body 14 to the outside, a leading-out part 18 for putting the sensor leading-out conductor 16 and an object to be checked in the connecting or contacting state, a protecting tube 20 permitting the sensor leading-out conductor 16 to pass through the interior thereof, and nitrogen gas supply equipment for supplying nitrogen gas to the leading-out part 18. The nitrogen gas is supplied from the nitrogen gas supply equipment to fill up the inside of the leading-out part, the inside of the protecting tube and the inside of the exterior body with nitrogen gas, and then the sensor main body is operated, whereby the sensor main body is always held in the nitrogen gas atmosphere and intercepted from the corrosive atmosphere so as to prevent corrosion of the sensor main body and the sensor leading-out conductor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a chemical resistant sensor.
More particularly, the present invention relates to a chemical resistant sensor system that operates well for a long period of time without corrosion even in a corrosive atmosphere.

[0002]

2. Description of the Related Art Semiconductor device manufacturing factories, chemical factories, and the like are provided with corrosion resistance against corrosive substances, and use chlorine-based gas,
2. Description of the Related Art Chemical resistance sensors for testing corrosive chemicals such as arsenic gas, hydrochloric acid, and sulfuric acid, and chemical resistance sensors used in corrosive atmospheres such as chlorine gas and arsenic gas are frequently used.
There are various types of chemical resistant sensors, such as an infrared sensor, an ultrasonic sensor, and a proximity sensor, depending on the inspection purpose, the inspection target, and the like.

Here, a configuration of a conventional chemical resistant sensor will be described with reference to FIG. FIG. 4 is a schematic diagram showing a configuration of a conventional chemical resistant sensor. As shown in FIG. 4, the conventional chemical resistant sensor 50 includes a sensor main body 52, and a chemical resistant outer body 54 that covers the sensor main body 52 and shields and protects the sensor main body 52 from a corrosive atmosphere. . The chemical-resistant exterior body 54 is formed of a chemical-resistant material such as Teflon (registered trademark) or vinyl chloride, and has corrosion resistance to corrosive chemicals. The chemical resistant sensor 50 is in contact with the object to be inspected via several sensor lead wires 56 coming out of the sensor main body 52.
Are wired so as to be exposed along the wiring path without being housed in the protective tube. The through-hole through which the sensor lead-out wire 56 passes through the exterior body 54 is hermetically sealed with a bushing or the like.

[0004]

However, the conventional chemical resistant sensor has the following problems. First, since the exterior of the chemical-resistant sensor is often exposed to a corrosive environment, pinholes may be generated in the exterior due to corrosion. At that time, a corrosive fluid such as a chemical solution enters the sensor body through the pinhole and damages the sensor function. There was also a problem that the circuit was short-circuited. Short circuits in electrical circuits can also be a significant accident. Second, when the chemical-resistant sensor is installed in a corrosive environment such as a chemical, the sensor main body is covered with a chemical-resistant outer body. In addition, there is a problem that the sensor body corrodes because the chemicals penetrate into the exterior body from the outlet of the sensor lead wire.

Accordingly, an object of the present invention is to provide a chemical resistant sensor system which has good chemical resistance and hardly causes problems such as corrosion.

[0006]

In order to achieve the above object, a chemical resistant sensor system according to the present invention comprises: a sensor body; a chemical resistant outer body which hermetically covers the sensor body;
A sensor lead wire connected to the sensor body and penetrating the exterior body and going out, and a lead portion formed as a chemical resistant box body, pulling the sensor lead wire into the box body, and connecting or contacting the inspection object, It is provided with a chemical-resistant protective tube extending from the outer body to the lead-out part and passing a sensor lead-out wire inside, and a nitrogen gas supply facility for supplying nitrogen gas to the draw-out part. The sensor body is operated after the supply, the inside of the drawer, the inside of the protective tube, and the inside of the exterior are filled with nitrogen gas.

In the present invention, the type, structure, inspection target, and the like of the sensor body are not limited as long as the sensor lead-out wire is provided. In addition, the chemical-resistant outer casing, chemical-resistant protective tube, and chemical-resistant box are designed to withstand the corrosiveness of the atmosphere around the area where the chemical-resistant sensor system is installed and the corrosion resistance of the inspection target. It is a corrosive box, and the material for forming the box is not limited as long as it has corrosion resistance to the atmosphere to which the chemical resistance sensor system is exposed, and is usually, for example, Teflon (registered trademark), Use vinyl chloride or the like.
The nitrogen gas supply equipment is not limited as long as it can supply nitrogen gas, and for example, a nitrogen cylinder, a factory nitrogen gas supply pipe, or the like can be used. By supplying nitrogen gas from the nitrogen gas supply equipment and filling the drawer portion, the inside of the protective tube and the exterior with nitrogen gas, and then operating the sensor body,
By preventing the corrosive fluid from entering the exterior body from the outside, the sensor body can be shielded from the corrosive atmosphere, and can be protected from corrosion and further short-circuit. Further, since the sensor lead wire itself is also maintained in the nitrogen gas atmosphere, there is no problem that a corrosive fluid permeates into the exterior body from the outlet of the sensor lead wire and corrodes the sensor body as in the related art. .

In a preferred embodiment of the present invention, an on-off valve is provided on a supply pipe for supplying nitrogen gas from the nitrogen gas supply equipment to the drawer, and a pressure gauge is provided on a supply pipe or drawer downstream of the on-off valve. And a pressure switch is provided, and when a nitrogen gas outflow hole such as a pinhole is opened in at least one of the exterior body, the protection tube, and the drawer, the pressure switch detects a decrease in the pressure of the nitrogen gas, and a signal to that effect is provided. Output. For example, by outputting a signal to that effect to the control room and issuing an alarm, it is possible to immediately take measures for the opening of the nitrogen gas outlet.

In another preferred embodiment of the present invention, the sensor main body is a contact type sensor, and the movable portion of the contact type sensor passes through a contact type sensor mounting through hole provided in the exterior body. A small annular gap is secured between the movable part of the contact type sensor and the hole wall of the through hole, and the movable part of the contact type sensor is Nitrogen gas is blown out from an annular gap between the body and the through hole. This makes it possible to maintain the operating contact type sensor in the nitrogen gas atmosphere, so that there is a gap in the operating part, and the contact type sensor, which was conventionally difficult to use in a corrosive atmosphere, can be used in a corrosive atmosphere. Can be used with

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Embodiment 1 This embodiment is an example of an embodiment of a chemical resistant sensor system according to the present invention. FIG. 1 is a perspective view showing a configuration of a chemical resistant sensor system according to this embodiment. FIG. 2 is a schematic diagram showing a chemical resistant sensor system filled with nitrogen gas. As shown in FIG. 1, the chemical resistance sensor system 10 according to the present embodiment includes a sensor main body 12,
An exterior body 14 that hermetically covers the sensor main body 12, a sensor lead-out lead 16 drawn out of the sensor main body 12, and penetrating through the exterior body 14 to the outside, and a sensor lead-out lead 16
Drawer 18 for connecting or contacting the inspection object
And a protective tube 20 extending from the exterior body 14 to the lead-out portion 18 and passing the sensor lead-out wire 16 therein, and a nitrogen gas supply facility 22 for supplying nitrogen gas to the lead-out portion 18.

The exterior body 14 is made of a chemical-resistant material, such as Teflon (registered trademark) or vinyl chloride, which has corrosion resistance against a corrosive environment.
Is provided with a through-hole 24 as a penetrating portion for penetrating through. The lead-out portion 18 is a box made of a chemical-resistant material such as Teflon (registered trademark), vinyl chloride, or the like, similarly to the case 14, and is a case provided to draw in the sensor lead-out lead 16. 14 and a connecting portion 2 between the through hole 26 having substantially the same diameter as the through hole 24 and the outside of the sensor lead wire.
8 and a supply port 30 for supplying nitrogen gas from the nitrogen gas supply equipment 22. In addition, the nitrogen gas supply equipment 22
A conduit 32 for introducing nitrogen gas from the supply port 30 to the supply port 30
The drawer 18 is further provided with a pressure gauge 36 for detecting the nitrogen gas pressure in the drawer 18 and, when the nitrogen gas pressure in the drawer 18 decreases to the set pressure, a signal to that effect is output. A pressure switch 38 is provided.

The protective tube 20 has an inner diameter slightly larger than the diameter of the through-hole 24 of the exterior body 14 and the through-hole 26 of the lead-out portion 18, and, like the exterior body 14, is made of Teflon (registered trademark), vinyl chloride or the like. This is a tube formed of a chemical-resistant material and having a sensor lead-out wire 16 penetrated therein. The protection tube 20 is air-tightly connected to the exterior body 14 and the drawer 18 so as to cover the through holes 24 and the through holes 26. Thus, the protection tube 20 protects the sensor lead-out conductor 16 from the exterior body 14 to the lead-out portion 18 from a corrosive environment.

When using the chemical resistant sensor system 10 of this embodiment, first, nitrogen gas is supplied from the nitrogen gas supply equipment 22 to the extraction unit 18 and the pressure is increased to a predetermined pressure slightly higher than the atmospheric pressure. Then, the on-off valve 34 is closed.
As a result, as shown in FIG. 2, the nitrogen gas fills the inside of the drawer portion 18, the inside of the protection tube 20, and the inside of the exterior body 14 through the protection tube 20, as shown in FIG. Prevent gas intrusion. In addition, the exterior body 14, the protection tube 2
0. When a pinhole is generated in the drawer 18 or the like, and nitrogen gas flows out of the pinhole and the pressure drops to the set pressure of the pressure switch 38, that is, the operating pressure, the pressure switch 38 detects a drop in the pressure of the nitrogen gas. Then, a signal to that effect is output to the control room, so that an immediate action can be taken.

Embodiment 2 This embodiment is another example of the embodiment of the chemical resistant sensor system according to the present invention, and FIG. 3 (a) shows the chemical resistant sensor of this embodiment. Schematic diagram showing the main parts of the system,
FIG. 3B is a schematic view showing a main part of the chemical resistance sensor system in use. The chemical resistance sensor system 40 of the present embodiment is the same as that of the first embodiment except that the sensor body is a contact type sensor 42 such as a micro switch and the nitrogen gas is blown out from the exterior body 44. It has the same configuration as.

In this embodiment, the contact sensor 42 is
Turn off the connection between the COM line and the NO line, and
This is a contact type sensor that turns on the connection with the line, and turns off the connection with the NC line, and turns on the connection between the COM line and the NO line. Since the contact type sensor 42 has the movable part 43 at the lower part, as shown in FIG.
The movable part 43 of the contact sensor 42 is attached so as to pass through the through hole 46 for attaching the contact sensor 4.
An annular gap having a small gap is secured between the hole and the through hole 46.

With the above configuration, in the chemical resistance sensor system 40 of the second embodiment, similarly to the first embodiment, the exterior body 44 is filled with nitrogen gas, and the nitrogen gas is filled in the case shown in FIG. As shown, the movable portion 43 of the contact sensor 42
Since the air blows out from the annular gap between the outer casing 44 and the outer body 44, the intrusion of corrosive gas is prevented. In the chemical resistance sensor system 40 according to the present embodiment, a nitrogen gas is always supplied to the drawer 18 at a predetermined pressure. Thereby, since the contact sensor 42 including the movable portion 43 is maintained in the nitrogen gas atmosphere, the contact sensor which has conventionally been difficult to use in the corrosive atmosphere can be used in the corrosive atmosphere.

[0017]

According to the present invention, a sensor main body, a chemical-resistant exterior covering the sensor main body, a sensor lead-out wire,
Formed as a chemical-resistant box, draws in the sensor lead-out wire, connects and contacts the object to be inspected, a chemical-resistant protective tube that passes the sensor lead-out wire from the exterior body to the drawer, and a nitrogen gas supply facility These constitute a chemical resistant sensor system. Nitrogen gas is supplied from the nitrogen gas supply equipment, and after filling the inside of the drawer, the inside of the protective tube, and the inside of the exterior with the nitrogen gas, the sensor body is operated to prevent the invasion of corrosive fluid from the outside. Thus, the sensor body can be protected from corrosion and short circuit.

In a preferred embodiment, a pressure gauge and a pressure switch are provided on a nitrogen gas supply pipe or a drawer,
When a nitrogen gas outflow hole such as a pinhole is opened in at least one of the exterior body, the protective tube, and the drawer,
The pressure switch detects a pressure drop of the nitrogen gas and outputs a signal to that effect. As a result, it is possible to immediately recognize that a pinball has occurred, and to respond appropriately.

Further, by securing a slight annular gap between the movable portion of the contact sensor and the hole wall of the through hole for attaching the movable portion of the exterior body, during operation of the contact sensor,
By allowing nitrogen gas to blow out from the annular gap between the movable part of the contact type sensor and the through hole of the exterior body,
Conventionally, a contact type sensor that has been difficult to use in a corrosive atmosphere can be used in a corrosive atmosphere. Also,
Since nitrogen gas is injected, ignition inside can be suppressed.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a configuration of a chemical resistant sensor system according to a first embodiment.

FIG. 2 is a schematic diagram showing the chemical resistance sensor system of Embodiment 1 in a state filled with nitrogen gas.

FIGS. 3A and 3B are schematic diagrams showing main parts of a chemical resistant sensor system according to a second embodiment, respectively.
It is a schematic diagram which shows the principal part of the chemical resistance sensor system in a use state.

FIG. 4 is a schematic diagram showing a configuration of a conventional chemical resistant sensor.

[Explanation of symbols]

10 ... Chemical resistance sensor system of Embodiment 1
2 ... Sensor body, 14 ... Outer body, 16 ... Sensor lead wire, 18 ... Drawer part, 20 ... Protective tube, 2
2 ... nitrogen gas supply equipment, 24 ... through-hole, 26 ... through-hole, 28 ... connection part, 30 ... supply port, 32 ... conduit, 34 ... on-off valve, 36 ... pressure gauge, 38 ... pressure switch, 40 ... chemical resistance sensor system of Embodiment 2, 42 ... contact type sensor, 43 ... movable part, 44 ...
... exterior body, 46 ... through-hole, 50 ... conventional chemical resistant sensor, 52 ... sensor, 54 ... exterior body, 56 ... sensor lead-out lead wire.

Claims (3)

[Claims] 1. A sensor body, a chemical-resistant exterior body that hermetically covers the sensor body, a sensor lead wire connected to the sensor body and penetrating through the exterior body to the outside, and formed as a chemical-resistant box body. A drawer for drawing in the sensor lead wire into the box body and connecting or contacting the object to be inspected; a chemical-resistant protective tube extending from the exterior body to the drawer portion, and passing the sensor lead wire inside, and a drawer After supplying nitrogen gas from the nitrogen gas supply facility to fill the drawer, protective tube, and exterior with nitrogen gas,
A chemical resistant sensor system characterized by operating a sensor body. 2. An on-off valve is provided on a supply pipe for supplying nitrogen gas from a nitrogen gas supply facility to a drawer, and a pressure gauge and a pressure switch are provided on a supply pipe or drawer downstream of the on-off valve. When a nitrogen gas outflow hole such as a pinhole is opened in at least one of the exterior body, the protective tube, and the drawer,
2. The chemical resistant sensor system according to claim 1, wherein the pressure switch detects a pressure drop of the nitrogen gas and outputs a signal to that effect. 3. The sensor body is a contact type sensor,
The movable part of the contact type sensor is attached to the exterior body so as to pass through the through hole for mounting the contact type sensor provided on the exterior body, and between the movable part of the contact type sensor and the hole wall of the through hole. A slight annular gap is secured, and when the contact type sensor is operated, nitrogen gas is blown out from the annular gap between the movable portion of the contact type sensor and the through hole of the exterior body. Item 7. The chemical resistant sensor system according to Item 1.