JPH02291945A - Underground-environment testing apparatus - Google Patents

Abstract

PURPOSE:To make it possible to estimate a durable life in a short time under various embedded environments with a compact apparatus by providing a shower which can supplies water at the upper part of a testing tank wherein soil that will form an embedded environment can be filled, providing an overflow tray and an observing window at the side surface, and providing a water draining port having a stop valve at the lower part. CONSTITUTION:A shower 3 which supplies water is provided at the upper part of a testing tank 1 whose upper part is opened and wherein soil 2 that becomes an embedded environment can be filled. An overflow tray 4 which drains excessive water and an observing window 5 are provided at the side surface of the tank 1. A water draining port 7 having a stop valve 6 is provided at the lower part of the tank 1. A heater 11 is provided in the inside of the testing tank 1 furthermore depending on the objective of the test. In this way, the deterioration and the corroding state of an underground embedded material such as covered steel pipe under the embedded environment can be readily observed frequently with a compact apparatus. Furthermore, various embedded environments can be realized, and a durable life can be estimated in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Use] The present invention relates to an apparatus for conducting underground environment tests, such as estimating the durable life of ylm pipes in a buried environment.

[Prior Art] In recent years, the environment in which coated steel pipes are used has been increasing in temperature, such as in the high-temperature transportation of heavy oil in vibrine lines, or in piping for district heating and cooling applications that pass steam or hot water. These coated steel pipes are basically used as underground pipes;
In addition, at high temperatures, the rate of deterioration of the coating material and the rate of corrosion of the steel pipe increase significantly, so it is extremely important to estimate the durable life of the pipe in advance while it is buried underground.

Conventionally, as a method for determining the durable life of coated steel pipes under such a buried environment, as shown in Fig. 2, a part of the coated steel pipe 12 used as a test specimen is borrowed from an existing outdoor buried hot water pipe 15, etc. However, since the construction work is large-scale, it is not only difficult to frequently observe the situation after burial, but also the buried environment is limited to the buried area, which is advantageous. The durability life of the pipes is not very versatile, and since it is operated at the actual operating temperature of the connected hot water pipes 15, it does not accelerate the deterioration of the coating material and the corrosion of the steel pipes, and it takes a huge amount of time to obtain the durability life. The disadvantage is that it requires

[Problems to be Solved by the Invention] In estimating the durable life of coated X4 pipes under such buried environments, the present invention aims to estimate the durable life in various buried environments in a short time using a small device. The purpose is to provide something that can also be used for testing the underground environment of other materials.

[Means for Solving the Problems] The present invention is a device used for the above-mentioned purpose, that is, a shower that supplies water to the top of an open top test tank 1 that can be filled with soil 2 serving as a burial environment. 3. Overflow tray 4 to drain excess water to the side and observation window 5
This is a soil environment testing device characterized in that it is equipped with a drain port 7 with a water supply valve 6 at the lower part, and a heater 11 is further provided inside the test tank 1 depending on the purpose of the test.

[Effects/Examples] Next, the configuration of the device of the present invention will be explained using the drawings.

Reference numeral 1 designates a test tank of the soil environment testing device according to the present invention, which is open at the top so that it can be filled with a soil bunker 2 that will serve as a burial environment. This test tank 1 includes a shower 3 that supplies water to the -L section;
It is equipped with an overflow tray 4 for discharging excess water on the side, a window 5 for observing soil conditions, and a drain port 7 with a water stopper F6 at the bottom. Several openings 8 are provided on the side of the test noise tank 1 to which the overflow tray 4 is attached, and the overflow tray r4 is attached to one of them, and the remaining openings are opened. By covering it with a blind lid 9, its height can be changed arbitrarily. 10 is a wire mesh for retaining the earth.

Depending on the purpose of the test, it may be necessary to further provide a heater 11, an example of which is as follows. In order to reproduce a situation where a high temperature fluid flows inside the N steel pipe l2, which is the test specimen, a heater 11 is loaded inside the pipe.

The remaining space is filled with a thermally conductive material to uniformly transmit the heat from the heater 11, and the temperature is detected and controlled by a temperature detection section 13 embedded in the inner surface of the tube. In addition, both open surfaces of the coated steel pipe l2 are covered with insulators i14 to prevent heat from escaping from the heater +1, and the contact surfaces are completely sealed with packing and sealant to prevent water from entering from the outside. .

The operation of the device of the present invention will be explained.

First, the test a#Ii is filled with a soil bunker 2 that serves as a burial environment, and the coated steel pipe 12 that serves as a test specimen is embedded therein. As for the burial environment, the places where the coated steel pipe 12 is actually buried can be roughly divided into two: above the groundwater level and below the groundwater level, so the apparatus of the present invention can reproduce both. In other words, since water is supplied to the soil voids by rainfall above the groundwater level, water is supplied by the shower 3 assuming this, and excess water is drained with the water valve 6 open. It is discharged from the mouth 7 and the environment is reproduced.

The composition ratio of air and water in soil voids is determined by the flow rate of one watering,
The watering time and the watering interval can be set arbitrarily.For example, in order to reproduce the buried environment due to average rainfall in Japan, the amount of water calculated by the annual average rainfall in Japan should be watered every day in Shower 3. In order to reproduce the desert burial environment, it is sufficient to stop watering by shower 3 since there is no rain water supply.

In addition, since all soil voids are filled with water below the groundwater level, shower 3 is
Set the water sprinkling flow rate, watering time, and watering interval, and use the Saiichi bar flow with the water valve 6 closed to dispose of excess water.
The environment is reproduced by discharging the paper from the tray 4.

The location of the groundwater table is in test chamber 1 of overflow tray 4.
The mounting height of the overflow tray 4 can be set arbitrarily depending on the mounting height of the overflow tray 4. For example, in order to reproduce a buried environment where the position of the ground water table changes with respect to the covered pipe 12, the mounting height of the overflow tray 4 can be set sequentially according to the situation. Just change it. At this time, the position of the groundwater table can be observed through the observation window 5.

Covered 1! In order to estimate the durable life of the pipe 12 in a short time, use at least three test tanks 1 that have the same buried environment, and set the temperature of the covered pipe 12 embedded in each test tank 12 to a temperature higher than the actual operating temperature. The durability life may be calculated by setting each temperature within a range below the temperature at which the coating material cannot maintain its shape (for example, the melting point in the case of an organic polymer material).

[Effects of the Invention] As explained above, by using the device of the present invention, it is easy to frequently observe the deterioration and corrosion of coated steel pipes and other objects buried in the ground in a buried environment by using small strikes from the device. It has the following advantages: it is possible to reproduce various buried environments, and its durability can be estimated in a short period of time.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view of the soil environment testing device of the present invention, and FIG. 2 is an explanatory view of a conventional method for determining the durable life of a coated steel pipe in a buried environment.

Claims (1)

[Claims] 1. A shower (3) that supplies water to the top of the test tank (1) with an open top that can be filled with soil (2) that will serve as the burial environment, and an overflow tray (3) that discharges excess water to the side. 4), an observation window (5), and a drain port (7) with a water valve (6) at the bottom.
) A soil environment testing device characterized by comprising: 2. The soil environment testing device according to claim 1, characterized in that a heater (11) is provided inside the test tank (1).