JPH0651212A - Observing device for inside of liquefied natural gas tank - Google Patents

Abstract

PURPOSE:To provide a compact device which is placed on the upper portion of a small tank and can be inserted into a small upper opening and easily observe the whole inner surface of the tank. CONSTITUTION:A device for observing the inside of an LNG tank includes a fiberscope portion 12 having an image fiber 2 and a lightguide fiber 6, a mirror head portion 10 provided at an end of the fiberscope portion to transfer a side image to the image fiber, a TV camera 14 connected to one end of the image fiber, an illumination light source 15 connected to one end of the lightguide fiber, a holddown member 21 to which the TV camera 14 or the like is secured, and a winding drum 22 freely rotatably mounted to the holddown member to wind the fiberscope portion to the outer periphery thereof.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to liquefied natural gas (LNG).
The present invention relates to an observation device capable of easily observing the inner surface of a tank that stores water.

[0002]

2. Description of the Related Art The cryogenic temperature (about -1) at which LNG is stored.
To observe the inside of the tank at
Although it is possible to use TV cameras and fiberscopes, real-time observation is not possible with still cameras, and TV cameras require strict consideration especially for explosion-proof, and it is difficult to operate both at extremely low temperatures. A sealed case is required to keep them warm. Therefore, a TV camera or the like sealed in the case has a large volume, which makes it difficult to operate.

On the other hand, the fiberscope is required to have a structure in which the vicinity of the objective lens at the tip can be used at an extremely low temperature, but it is connected to the base ends of the image fiber and the light guide fiber constituting the fiberscope, respectively. Since the TV camera and the illumination light source are located outside the tank, there is no need to keep them warm, and the fiber portion does not need to keep warm. Therefore, the part inserted into the tank becomes compact.

Further, since the image fiber is used for transmitting the observation image and the light guide fiber is used for illumination at the same time, real-time observation is possible. Furthermore, a TV camera can be connected to the proximal end of the image fiber located outside the tank for TV monitoring, and the use of a fiberscope is the most effective method for observation inside a cryogenic LNG tank.

[0005]

However, when observing the inside of a tank in which LNG is stored by the fiberscope, the fiberscope is inserted vertically from the mouth of the upper part of the tank, and therefore the same as the height of the tank. A length of fiberscope is required. Also,
Since the fiberscope is directly inserted from the mouth of the upper part of the tank, there is a disadvantage that only the inner bottom surface of the tank can be observed as it is.

In order to connect a TV camera to the fiberscope and observe it on a monitor, the illumination light source, the monitor TV, etc. must be arranged above the narrow tank.

Further, when the silica-based fiber is bent to a small diameter, it may be broken and cannot be wound below a predetermined diameter. Therefore, this also makes it difficult to operate on a narrow tank, and may hinder the insertion and observation work.

The present invention has been made in view of the above circumstances. When the image on the inner side surface of the tank is introduced and transmitted to the fiberscope, the TV camera, the illumination light source, etc. are arranged and stored, and the quartz fiber is damaged. It is an object of the present invention to provide an observation device in an LNG tank that can be easily wound and compacted without being wound and can be easily set on the tank.

[0009]

In an observation apparatus for an LNG tank according to the present invention, a fiberscope portion having an image fiber and a light guide fiber, and a fiberscope portion provided at the tip of the fiberscope portion, driven to rotate by remote control. A mirror head that sends a lateral image to the image fiber of the fiberscope section, a television camera connected to the proximal end of the image fiber of the fiberscope section, and illumination connected to the end of the light guide fiber. A light source, a fixing portion to which the television camera and the illumination light source are fixed, and a winding drum that is rotatably attached to the fixing portion and winds the fiber scope portion around the outer periphery are provided as means for solving the problem. .

[0010]

Since the observation device in the LNG tank according to the present invention has the above-mentioned structure, the insertion depth of the fiberscope into the tank can be easily adjusted and the mirror head portion can be rotated to adjust the position within an arbitrary position. The side can be observed.

The fiberscope is rotatably attached to a fixed portion to which a TV camera or the like is fixed,
The quartz fiber is wound on a winding drum with a diameter that does not break, and the fiberscope is pulled out and rewound by rotating this, so it is compact and does not occupy a lot of space. Once set, it can be easily operated without damaging the fiber.

[0012]

1 to 5 show an embodiment of an observation apparatus in an LNG tank according to the present invention, in which reference numeral 1 is an objective lens for forming an image on the front end surface of an image fiber 2.

Since the objective lens 1 is used in the LNG, the objective lens 1 is opened in the window 3 so that the LNG does not enter.
An object cell 5 is constructed by hermetically sealing the inside of a case 4 with a mark, and holding the inside of the case 4 in a vacuum to prevent dew condensation.

As a method for hermetically sealing the objective lens 1 in the case 4, as shown in FIG. 1, both ends are made into windows 3 and the end face of the image fiber 2 and the window 3 are brought into close contact, and as shown in FIG. Is the window 3 and the other end is the image fiber 2
There is a method in which the casing 2a of 1 is put in the case 4, and the casing 2a is adhered and sealed, and both are widely used.

The light guide fiber 6 is provided in parallel with the image fiber 2 and has a light guide cell 7 attached to the tip thereof.

At the tip of the objective cell 5 and the light guide cell 7, a side image is guided to the image fiber 2 45.
An angled mirror 8 is attached. This mirror 8
Is housed in a mirror case 10b provided with a small hole 10a through which LNG comes in and out, and constitutes a mirror head unit 10. The mirror head portion 10 is rotatably attached to the tip ends of the objective cell 5 and the light guide cell 7, and is rotationally driven by a small motor 9 having a speed reducer 9a.

Further, a lead wire 9 for driving the image fiber 2, the light guide fiber 6, and the small motor 9 in a stainless flexible tube 11 coated with a fluororesin.
b is accommodated to form the fiberscope unit 12. The fiberscope portion 12 has almost the same length as the depth of the tank. Reference numeral 13 is a spring wound around the stainless flexible tube 11 for reinforcement.

As the respective fibers and lead wires used, for example, the image fiber 2 has 30,000 pixels and a fiber diameter of about 2 mm, and the light guide fiber 6 has a fiber diameter of 0.
Uses 50 pieces of 65 mm silica fiber and uses lead wire 9b
Used a fluororesin-coated copper wire, but is not limited thereto.

A TV camera 14, an illumination light source 15 and the like are connected to the base end of the image fiber 2 of the fiber scope section 11 and the base end of the light guide fiber 6 as shown in FIGS. . These TV cameras 14 etc.
The fixing member 21 is fixed to the fixing member 21 that can be carried.
A take-up drum 22 having a diameter corresponding to the permissible bending diameter of the image fiber is rotatably attached to. A rotary connector 23 is attached to the rotary shaft of the winding drum 22, whereby the video signal of the TV camera 14, the power source,
The lead wire 9b of the small motor can be taken out.

Regarding the illumination light source 15, a light source stand 15a is attached to the side of the rotary shaft of the winding drum 22 on the side opposite to the rotary connector 23, and a xenon light source (illumination light source) 15 is attached.
The light guide fiber branched from the vicinity of the base end of the image fiber 2 was taken out from the rotary shaft and connected to the light source 15. The light guide fiber 6 was made rotatable at the connecting portion with the light source 15 to prevent the light guide fiber 6 from being twisted. In the figure, 24 is a camera controller, 25 is a TV monitor, 26 is a mirror head controller, and 27 is a caster.

A 100 VA power source for the camera power source was supplied from the rotary connector 23 of the winding device, and the video signal output was connected to the TV monitor. In addition, the controller was connected to the motor lead wire from the rotary connector in order to perform remote control (start, stop, rotation direction reversal) of the rotating mirror head.

In order to observe the inner surface of the LNG tank using the above apparatus, first, the fixing member 21 is placed on the LNG tank.
Is placed near the upper opening of the tank.

Next, the mirror head portion 10 at the tip of the fiber scope portion 12 is inserted from the upper opening of the LNG tank and the winding drum 22 is rotated to feed out the fiber scope portion to a predetermined length and a rotary mirror head controller. The TV camera 14, the illumination light source 15, the TV monitor 25, etc. are turned on while the mirror head is rotated by operation.

As a result, the inside wall of the tank is photographed by the TV camera 14 and monitored by the TV monitor 25. At this time, the fiber scope portion 12 is extended or wound, and the mirror head portion 10 is rotated to observe the entire inner surface of the tank. Further, since the electricity is supplied through the rotary connector 23, the fiberscope portion 12 is not twisted, and it is possible to easily monitor the entire inner surface.

[0025]

As described above, the LN according to the present invention
The observation device in the G tank is a narrow tank in which a take-up drum around which a fiberscope is wound is rotatably attached to a fixing member to which a TV camera, an illumination light source rotary connector, etc. are fixed. It can be easily placed on top and is easy to work, and the fiberscope part is expanded and contracted without being twisted because it is connected to the TV camera etc. on the fixed member by the rotary connector, and by the rotation of the mirror head part, The entire inside surface of the tank is easily observed. Furthermore, the outer diameter of the mirror head is, for example, φ75 m.
At about m, there is an advantage that the fiberscope can be inserted into the tank even if the upper opening in the tank is small.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of an objective cell.

FIG. 2 is a vertical sectional view showing another example of the objective cell.

FIG. 3 is a vertical cross-sectional view of a portion including a mirror head near the tip of the fiberscope.

FIG. 4 is a side view of a fixing member to which a drum is attached.

5 is a view taken along the line VV of FIG.

[Explanation of symbols]

1 ... Objective lens, 2 ... Image fiber, 2a ... Casing, 3 ... Window, 4 ... Case, 5 ... Objective cell, 6 ... Light guide fiber, 7 ... Light guide cell, 8 ... Mirror,
9 ... Small motor, 9a ... Reducer, 9b ... Lead wire, 10
... mirror head part, 10a ... small hole, 10b ... mirror case, 11 ... stainless steel flexible tube, 12 ... fiberscope part, 13 ... spring, 14 ... TV camera,
15 ... Illumination light source, 15a ... Light source base, 21 ... Fixing member,
22 ... Winding drum (drum), 23 ... Rotary connector, 24 ... Camera controller, 25 ... TV monitor, 2
6 ... Rotating mirror head controller, 27 ... Casters

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sadao Chiyoshi 1440 Rokuzaki, Sakura City, Chiba Prefecture, Sakura Factory, Fujikura Cable Co., Ltd. (72) Kazuo Sanada, 1440, Rokuzaki, Sakura City, Chiba Fujikura Cable, Ltd. (72) Inventor Kazumi Onui 9-10, Misonodai, Fujisawa City, Kanagawa Prefecture (72) Inventor, Takaaki Tanaka 93-15, Okidocho, Midori-ku, Chiba City, Chiba Prefecture (72) Inventor, Ken 4 Shimotakaido, Suginami-ku, Tokyo −39−5 (72) Inventor Hiroharu Suyama 9 of 1781, Hara City, Ageo City, Saitama Prefecture

Claims (1)

[Claims] 1. A fiberscope part having an image fiber and a light guide fiber, and a mirror head which is provided at the tip of the fiberscope part and is driven to rotate by a remote control to send a side image to the image fiber of the fiberscope part. Section, a television camera connected to the proximal end of the image fiber of the fiberscope section, an illumination light source connected to the proximal end of the light guide fiber, and a fixing section fixing the television camera and the illumination light source, An observing device in a liquefied natural gas tank, comprising: a winding drum that is rotatably attached to a fixed portion and that winds the fiberscope portion.