JP2967289B2 - Corrosion protection device for tank bottom plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application field> The present invention relates to an anticorrosion device for a bottom plate of a steel tank for storing water, oil, and the like.

<Prior Art> Conventionally, as shown in FIG. 2, under a bottom plate b of a steel tank a, asphalt is provided to prevent the iron plate of the bottom plate b from being corroded by water contained in soil. c is laid.

<Problems to be Solved by the Present Invention> The above-mentioned conventional technology is based on the problem that the bottom plate b
Has no problem because it is in intimate contact with asphalt c which is a water barrier material.

However, when the liquid in the tank a decreases, the bottom plate b is deformed and becomes uneven, and a gap d is formed between the bottom plate b and the asphalt c.

Therefore, air or water containing salt enters and stays in the gap d, and often corrodes the bottom plate b in the long term.

As means for preventing such corrosion, painting of bottom plate b or cathodic protection may be considered, but painting has problems in durability, and cathodic protection should be used due to the danger of fire in oil tanks. Can not.

As a result, the corrosion of the tank bottom plate b progresses, and it is necessary to perform repair work once every ten years.

<Object of the present invention> The present invention has been made to solve the above problems, and provides a tank bottom plate corrosion prevention device capable of semi-permanently preventing corrosion of a tank bottom plate at low cost. The purpose is to:

<Means for Solving the Problems> The present invention relates to an anticorrosion device for a tank bottom plate, which is provided around an outer periphery of a tank bottom and has a bottom formed of a water-blocking sheet and a container between the water-blocking sheet and the tank bottom plate. A corrosion prevention device for a tank bottom plate, characterized by comprising a gap holding material disposed in the container and an anticorrosion liquid filled in the container.

<Description of the Present Invention> Hereinafter, the present invention will be described in detail with reference to the drawings.

<A> Anticorrosion liquid storage container As shown in FIG.
A closed container whose bottom is formed of a water-impervious sheet is provided.

This container includes a side plate 2, a top plate 3, and a waterproof sheet 4.

The side plate 2 is formed in an outer shape around the lower portion of the side wall 11 of the tank 1.

The upper end of the side plate 2 and the side wall 11 of the tank 1 are connected by the top plate 3.

A flexible water-impervious sheet 4 is laid under the bottom plate 12 of the tank 1, and the periphery of the water-impervious sheet 4 is connected to the lower end of the side plate 2 of the tank 1.

Thereby, a closed container can be formed around the bottom of the tank 1.

An injection tube 5 communicating with the inside of the container is provided on the top plate 3 and the like of this container.
, And a valve 51 is attached to the liquid injection tube 5.

The injection pipe 5 is used for adjusting the level of the anticorrosion liquid when the tank 1 is completed, and for replacing the anticorrosion liquid when it has deteriorated.

In addition, a vent pipe 6 which is always open and communicates with the atmosphere is also provided so that the level of the anticorrosive liquid can be freely raised and lowered.

<B> Void Retaining Material The void retaining material 7 is disposed between the impermeable sheet 4 and the tank bottom plate 12 to secure a void between the two.

 For example, a gravel material is used.

The gap holding member 7 has a role of securing a gap for the anticorrosive liquid to sufficiently flow under the tank bottom plate 12 through a gap such as gravel material, and a role of transmitting the weight of the tank 1 to the foundation ground.

Further, when the tank bottom plate 12 is manufactured, the tank bottom plate 12 also serves to protect the impermeable sheet 4 from heat generated by welding.

<C> Anti-corrosion liquid The anti-corrosion liquid 8 is sufficient at low cost, for example, petroleum oil (heavy oil or the like) having low volatility or water whose oxygen has been expelled by boiling or the like.

The anticorrosive liquid 8 is filled into the container configured as described above via the liquid injection tube 5.

The liquid level of the anticorrosive liquid 8 rises and falls depending on the deformation state of the bottom plate 12 of the tank 1, but is filled so that the liquid level can always be maintained at a position higher than the bottom plate 12.

For example, the deformation of the bottom plate 12 of the tank 1 having a diameter of 100 m is 2 cm.
If this is the case, the distance between the tank side wall 11 and the container side plate 2 should be 50
cm, the liquid level will rise and fall
It can be reduced to about 50cm.

<Operation of the Present Invention> An air gap is secured between the bottom plate 12 of the tank 1 and the impermeable sheet 4 by the air gap holding material 7.

Therefore, the anticorrosive liquid 8 in the container wraps around and contacts the entire surface of the bottom plate 12 and corrosion can be prevented.

When the bottom plate 12 is deformed, the level of the anticorrosive liquid 8 naturally rises and falls, so that the anticorrosive liquid 8 can always keep contact with the bottom plate 12 regardless of how the bottom plate 12 is deformed.

<Effects of the Present Invention> Since the present invention has been described above, the following effects can be expected.

<A> According to the present invention, even when the tank bottom plate is deformed into an uneven shape, the tank bottom plate can always maintain contact with the anticorrosive liquid.

Therefore, air or water does not enter from the outside, so that corrosion of the tank bottom plate can be prevented semipermanently.

 Therefore, repair costs can be reduced.

<B> Since the device of the present invention has a simple structure, it can be installed without largely changing the conventional tank design method, so that the cost can be reduced.

<C> The anticorrosion liquid naturally rises and falls depending on the deformation state of the tank bottom plate, and can constantly maintain contact with the tank bottom plate, so that maintenance and management are easy and the cost is low.

<D> Since the anticorrosion liquid is contained in a water-impervious container, there is no risk of contaminating the surrounding ground by leakage.

Further, since the contact area with the air is small, a change in liquid quality is small.

[Brief description of the drawings]

 FIG. 1: Illustration of anticorrosion device for tank bottom plate of the present invention FIG. 2: Illustration of prior art

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C23F 11 / 00,15 / 00 B65D 90/22

Claims (1)

(57) [Claims] An anticorrosion device for a tank bottom plate, comprising: a container provided on the outer periphery of the tank bottom and having a bottom surface formed of a water-impervious sheet; a gap holding material disposed between the water-impervious sheet and the tank bottom plate; The height of the container is set higher than the position of the tank bottom plate, and the liquid level of the anticorrosion solution is always maintained higher than the tank bottom plate even when the tank bottom plate is deformed. An anticorrosion device for the tank bottom plate, characterized in that the container is filled with the possible amount.