JPS60252247A - Inside checking method of liquid preserving tank - Google Patents

Abstract

PURPOSE:To check the inside of even a large-sized tank or a tank for low- temperature liquefied gas very easily and quickly with less expenses by performing remote control of a robot having a checking sensor which is floated on a preserved liquid in the tank. CONSTITUTION:A main body 12 having floating bodies 11 such as tanks or the like is provided with a driving device which consists of two pairs of light and left propulsive impellers 13a and two driving sheels 13b, two idler wheels 14 as guides, and an object part of an optical fiber scope consisting of a sensor 8e for peripheral wall, a sensor 8f for top plate and a sensor 8g for bottom plate, thus constituting a robot R. The liquid level in the liquid preserving tank is controlled to a height corresponding to a peripheral wall part to be checked of the inside wall of the tank, and wheels 13b are pressed to the inside wall of the tank by impellers 13a, and the robot R is moved along the peripheral wall part in this state. Thus, the peripheral wall part is checked with the sensor 8e by remote control from the outside of the tank.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is applicable to low-temperature liquefied gases such as liquefied natural gas, petroleum gas, nitrogen gas, and oxygen gas;
4. The present invention relates to a method of internally inspecting a tank that stores a liquid substance.

[Prior Art] Conventionally, in tanks such as petroleum tanks that store room-temperature liquid materials, a so-called open inspection was generally performed in which all phases of the internal liquid were discharged and an operator entered the tank.
The low-temperature liquefied gas tank is a complete product at the time of manufacturing.We have established a convex management system to ensure thorough design, construction, and inspection. 1. Internal inspections are no longer necessary during this period, and up until now, there has been no suitable method for internal inspections of low-temperature liquefied gas tanks.

[Problem to be solved by the invention 1 1-However, in order to open and inspect the inner peripheral wall of a large tank, it is necessary to install a high scaffold inside the tank, and the inspection requires a lot of cost and time. There was a drawback.

Furthermore, even in tanks for low-temperature liquefied gas, there is a possibility that they will be subjected to external forces due to earthquakes, etc. during long-term use, so it is advisable to check the internal soundness to ensure even higher levels of safety. Therefore, it is necessary to discharge the entire amount of low-temperature liquefied gas, heat up the tank, and conduct a so-called open inspection by one worker entering the tank, as conventionally done for room-temperature tanks. However, it takes a lot of effort and time to discharge and refill the low-temperature liquefied gas, as well as to heat up and cool down the tank, and a huge amount of cold energy is consumed to cool down the tank.

Furthermore, the economic burden associated with long-term operational loss of the tank is enormous, and the larger the facility, the more expensive the inspection costs, for example, hundreds of millions of yen.

An object of the present invention is to enable an extremely simple, rapid, and low-cost internal inspection of even a large tank or a tank for low-temperature liquefied gas.

[Means for Solving the Problem] The characteristic means of the internal inspection method according to the present invention is to adjust the liquid level in the liquid storage tank to a height corresponding to the peripheral wall portion of the inner wall of the tank that is to be inspected. , 70 A robot with sensors, a floating body, and a propulsion device for inspection of solid wall parts,
While floating on the tank's built-in liquid, whose level has been adjusted, the propulsion machine is controlled remotely from outside the tank to move the circumference along the section, and the sensor is used to inspect the circumferential wall from outside the tank. The functions and effects are as follows.

``Function'' In other words, if the liquid level in the tank is adjusted according to the height of the peripheral wall part to be inspected by means such as transferring the liquid to another tank, the liquid can be removed. Appropriate inspections, such as flaw detection, thickness inspection, and visual inspection, can be performed on the surrounding wall portion by remote control from outside the tank with a floating robot and by using sensors from outside the tank.

[Effect of the invention 1] As a result, operations that require a lot of time and money, such as discharging the entire amount of liquid from the tank and assembling and dismantling inspection scaffolding inside the tank, are no longer required. Even if there is a problem, it is now possible to conduct an internal inspection of the peripheral wall portion at a desired height easily, quickly, and at low cost.

In particular, when dealing with tanks for low-temperature liquefied gas, a large amount of labor and work is required due to things such as completely discharging and refilling the low-temperature liquefied gas, hot-up and cool-down of the insulated tank, and safety measures for entry. Inspections can be carried out easily and quickly without the need for time, and by eliminating the loss of thermal energy associated with cooling down the insulated tank, inspections can be carried out advantageously in terms of energy conservation, and internal inspections can now be carried out extremely advantageously. .

On the other hand, it is also possible to make the robot levitate and sink in the liquid by adjusting its buoyancy and adjust the height of the robot to the peripheral wall part to be inspected so that the above effect cannot be obtained. However, there is still room for improvement in that the buoyancy adjustment mechanism is complicated.

However, according to the present invention, since the robot is floated on a liquid substance, the robot can be easily and reliably maintained at a predetermined level and moved along the peripheral wall, and since no buoyancy adjustment mechanism is required, the robot can be easily and reliably maintained at a predetermined level and moved along the peripheral wall. It can be used as a robot, and has many advantages in terms of robot configuration and operation.

[Example] Next, examples will be shown.

@1 As shown in Figure 1, a heat insulating material (3) is filled between the tank inner wall fl+, which is made of a material with high cryogenic strength such as nickel steel or aluminum iron, and the tank outer wall (2), which is made of steel plate. In the insulated tank σ) consisting of
By exchanging low-temperature liquefied gas with another insulated tank, the liquid level (Ll) of the built-in low-temperature liquefied gas can be adjusted from the insulated tank (low-temperature liquefied gas supply path to the sword + 517 Jl).
Adjust the liquid level in the valve (V,) provided at the valve (V) and -ti to an appropriate level.

Before, at the same time or after the liquid level adjustment, the case (C) 'lr-closed valve (V,)I
C Connect.

Before or after connecting the case (C) to the pulp (V,), store the robot (R) in the case (C).

Open the pulp (V,) and transfer the low temperature liquefied gas to the insulated tank (
'r) to case (C) gradually.
) The robot (R) is cooled down to a sufficiently low temperature to prevent cooling damage, and then floated on low-temperature liquefied gas.

The propulsion device of the robot (R) is remotely controlled from outside the insulating tank (r) using the operation panel (6) placed outside the case (C), and the robot (R) is inserted into the insulating tank σ) through the pulp (V,). ) Get money.

If necessary, the liquid level (L
2) is adjusted to a height corresponding to the peripheral wall portion (la) of the tank inner wall f+) that is subject to inspection, and the vertical position of the robot (R) floating on the low-temperature liquefied gas is adjusted.

With the robot (1'6) floating, it was moved along the peripheral wall part (1a) by remote control of the propulsion device, and the objective part of the optical fiber scope prepared for the robot (R) and the outside of the case (C) were removed. The eyepiece allows visual inspection of the peripheral wall part (1a) from outside the insulated tank (T).

Furthermore, if necessary, the liquid level (L2) in the insulated tank (T) can be adjusted and a visual inspection of the peripheral wall portion (1a) at an arbitrary height can be performed in the same way.
) in an appropriate direction, visually inspect the top plate (1b) and bottom plate (1c).

Once the inspection is complete, the liquid level (
Adjust L, ) in the same way as when inserting the robot) (R), move the robot (R) into the case (C), close the pulp (V,), and remove the case (C) Th Remove.

Incidentally, during the inspection, the pulp of the low temperature liquefied gas supply path from the heat insulating tank (T) may be closed and cannot be opened even with force. Furthermore, if the low-temperature liquefied gas is flammable, the case (C) is sealed, but if the low-temperature liquefied gas is nonflammable and scary, the case (C) may be opened.

As shown in Figure 2, the case (C) is connected to the case (C).
In D), the power supply coaxial cable (7h) for the robot (R), the two operating coaxial cables for the propulsion machine (7b), and the optical fiber scope fiber cable (8a) are connected to the motor (Ml) and (M2). ).

(M3) Winder (9a) T (
9b) + (9c) VC winding, winding machine (9a) + (9b
) power supply and sweeping coaxial cables (7a) and ('7b
) 'k, terminal board (10
), and all necessary operations can be performed using the operation panel (6). Optical fiber of winder (9C) (
8a), the optical fiber (8c) connected to the light source (8d) outside the case and the eyepiece seal (8b) can be freely connected and separated, and when separated, the optical fiber (8a) is connected to the winder (9c) side.
It is connected via a connector that allows rotation.

A heater (F()) is provided between both cases (C) and (D) to heat the cables so that they can be easily wound.

(R) (r) As shown in Figures 3 and 4, the main body (12) is configured to float on a floating body (11) such as a tank, and two propulsion impellers are installed on the left and right sides. A propulsion device (13a) I (13b) consisting of (13a) and - driving wheels (13b), one idling wheel (14) that serves as a guide when moving within the pipe, and an objective portion for the peripheral wall (8e), Optical fiberscope objective f) consisting of a top plate objective part (8f) and a bottom plate objective part (8g)
[8e)・(8f)+(8g) are provided. The propulsion impeller F (13a) is configured so that the left and right ones are driven by electric motors (M4) and (M5) that can be operated in forward, reverse and stop directions separately, and the left and right impellers (13a) By changing the relative fishing part UJ shape 1, it is possible to move forward and backward and change direction. 1.1 moving vehicle N1 (13b)
Electric motor (M6), (M
, ), and with the driving heavy wheels (13b) pressed against the tank inner wall f+) by the propulsion impeller (13a), the robot (R) is moved by the action of the driving wheels (13b).
It is configured such that it can be moved along the peripheral wall portion (1a).

Example according to E] Next, another example will be shown.

If the robot (R) is to be placed in an insulated tank (η), the robot (R) may be suspended from a pulp (v2) provided above the tank as shown in Figure 5. Set the liquid level (L3) in the tank (T) to the highest level, and lower the case (C) to pulp (v2).
After connecting the robot (R) in the case (C) to the pulp (V2) and cooling it sufficiently, place it in the insulated tank (T) with the hanging distance shortened. In addition, the robot (R) is recovered into the case (C) with the liquid level (L3) in the insulated tank (T) at its highest level. This is useful for underground tanks.

The target tank 0') may be one that stores a room-temperature substance such as petroleum, and any liquid substance may be stored therein.

The specific means for adjusting the liquid level in the tank (T) can be changed as appropriate.

The propulsion machines (13a) 1 (13b) of Robots l-(R) are:
For example, a combination of a screw and a rudder, a combination of a front-rear movement screw and a left-right movement screw, and other suitable vCg
, can be changed. In addition, the robot (R) is equipped with a level detector such as an ultrasonic type, and a fixing mechanism such as a suction type that fixes the robot (R) to the tank inner wall (1) during inspection.
The configuration of the robot (R) can be changed as appropriate.

In the configuration for inspection, the objective part (8e) of the optical fiber six-scope is provided so that its direction can be changed by remote control from the operation panel (6), and a television camera is attached to the eyepiece 1 (8b). We have configured it so that it can be inspected on a monitor TV, installed an ultrasonic device to detect defects in the thickness of the inner tank wall + 1) and welded parts, and even equipped it with multiple types of inspection equipment. It can be selected as appropriate, and in short, an appropriate inspection sensor for the tank inner wall i1+ (
8e) may be provided.

The operation of the propulsion devices (13a) + (13b) and the collection of information from the inspection sensor (8e) can be performed using various technologies such as wireless methods.

[Brief explanation of drawings]

1 to 5 show embodiments of the present invention, □First
2 is a schematic explanatory diagram of the inspection state, FIG. 2 is a schematic explanatory diagram of the inside of the case, FIG. 3 is a schematic diagram of the robot, and FIG. 4 is a schematic side view of the robot. FIG. 5 is a schematic explanatory diagram showing another inspection state. (1)... Tank inner wall, (la)... Surrounding wall part, (8e)... Inspection sensor, (11)...
...Floating body, (13a)T (13b)...4
1a machine, (C'l... case, (R'l...
...Robot, (T')...Insulated tank. Agent Patent Attorney Osamu Kitamura

Claims (1)

[Claims] The liquid level in the liquid storage M tri tank (T) is adjusted to a height corresponding to the peripheral wall portion (1a) to be inspected of the tank inner wall fi+, and ) inspection sensor (8e), floating body (11) and propulsion device (13)
a). (13b') with the robot (R) being level-adjusted and floating on the floating body (11) in the tank's built-in liquid,
The sensor (8e) is moved along the circumferential wall portion (la) by remote control from outside the tank (T).
) is an internal inspection method for a liquid storage tank in which the peripheral wall portion (la) is inspected from outside the tank (T).