JP2500983Y2 - Zinc-plated tank bottom plate outer surface potential measuring device - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a galvanized tank bottom plate outer surface potential measuring device in which corrosion protection is applied to the outer surface of the tank bottom plate by the gin sheet method.

“Prior Art” Preventing corrosion of outdoor ground tanks that store hazardous materials is an important safety issue. As a method for preventing the corrosion of the outer surface of the tank bottom plate, a method of providing an insulating layer such as asphalt sand on the tank foundation is adopted. However, even in this construction method, rainwater or dew condensation water may be generated between the bottom plate and the insulating layer, and the outer surface of the tank bottom plate may be corroded to cause pitting corrosion.
In order to prevent this corrosion, a zinc plate is laid under the bottom plate near the annular plate with the most severe corrosion.
The so-called gin sheet method proposed in 026, JP-A-56-123289 and the like has been adopted in recent years. According to this, since the zinc plate and the tank bottom plate are electrically connected, even if rainwater or the like enters between them, the bottom plate is protected against corrosion by the anticorrosion current flowing out from zinc, which is approximately equal to zinc. It is supposed to be. In this way, when corrosion protection by the gin sheet method is applied to the outer surface of the tank bottom plate,
It has been confirmed by a laboratory test that the electric potential of the outer surface of the bottom plate is approximately the electric potential of zinc, but it is naturally important to confirm it in an actual machine.

Therefore, although there is a great demand from customers who measure the bottom plate outer surface potential of an actual machine that has been installed with the gin sheet method, it is impossible to measure it with the actual machine due to the following circumstances. That is,
To measure the potential on the outer surface of the tank bottom plate, generally, as shown in FIG. 3, the reference electrode 3 is embedded in the basic sand 5, and the voltmeter 4 is connected between the lead wire 8 and the lead wire 6 from the tank bottom plate 1. It is done by measuring.

However, in the gin sheet method, the zinc plate 2 is laid directly under the bottom plate 1 as shown in FIG. 5, and the potential of the bottom plate 1 is not measured by the measuring procedure as shown in FIG. That is, it is necessary to insert the verification electrode between the bottom plate 1 and the zinc plate 2 to interpose it, but this is not possible under the bottom plate to which a large load is applied. By the way, in order to confirm the gin sheet construction method, Fig. 4 shows the procedure for measuring the potential by a laboratory test. A gap is provided between the iron plate 1 and the zinc plate 2 of the model bottom plate, and the electrolyte 7 is retained so that a capillary tube is provided in this gap. It is supposed that the electric potential of the iron plate 1 is measured by inserting the verification electrode 3 included therein. That is,
The measurement is made possible by forming a gap between the iron plate 1 and the zinc plate 2 which holds the electrolyte 7 into which the reference electrode 3 can be inserted.

"Problems to be solved by the invention" The present invention has been made in view of the circumstances described in the above-mentioned conventional technology. The purpose of the present invention is to apply zinc sheet laying with anticorrosion by the gin sheet method. Even on the outer surface of the tank bottom plate (actual machine), without changing the anticorrosion system of Fig. 5,
Moreover, the present invention is intended to provide an electric potential measuring device capable of measuring the electric potential at a specified position on the bottom plate without short-circuiting the measuring system and the anticorrosion system even if a load is applied.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the measuring device in the present invention is provided with a hole for electric potential measurement communicating with a bottom plate at a predetermined position of a laid zinc plate and a hole corresponding to the hole. A reference electrode made of plate-shaped zinc is installed in the hole through an insulating material having the, and a water retaining material is filled in the hole.

It is advisable to install a resin tube for replenishing water from the outside into the above-mentioned measurement hole.

[Operation] According to the device of the present invention, although the zinc plate is laid directly below the bottom plate, the reference electrode is connected through the laid zinc plate and the measurement hole filled with the electrolyte that penetrates the insulating material. Since it passes the pass, it becomes possible to measure the electric potential. In addition, if a tube for water supply is installed from the outside into the hole for measurement, if the measurement part is dry at the time of measurement, it is possible to supply water to that part and make it ready for measurement. .

[Example] An example will be described with reference to the drawings.

1 and 2, a potential measuring hole 11 is formed at a predetermined position of the zinc plate 2 introduced in FIG. The potential on the outer surface of the tank bottom plate 1 can be measured by inserting a reference electrode into the hole 11 and measuring the potential, but in the present invention, an insulating material 9 having a potential measuring hole 11 'is laid under the zinc plate 2. The potential measuring hole 11 'is aligned with the hole 11' of the zinc plate 2. A plate-shaped zinc reference electrode 10 is laid under the insulating material 9 as a reference electrode,
The other end is pulled out to the outside of the tank bottom plate 1. The reference electrode 10 is coated with an insulating material except for the measurement hole 11 ', and the other end is normally connected to the tank bottom plate 1 and the zinc plate 2 by a lead wire 14 and short-circuited. is there.

A holding material 12 capable of holding an electrolytic solution is packed inside the measurement holes 11 and 11 '. Further, as shown in FIG.
If water is supplied to the holes 11 and 11 'from the outside of the tank bottom plate, the presence of the electrolyte can be secured even when the measurement site is dry, and measurement can be performed.

In a tank that has been used for several weeks after the construction of the gin sheet method, water (electrolyte) may stagnate in the tank bottom plate 1 and zinc plate 2 and measurement holes 11 and 11 'in Fig. 4 due to infiltration and generation of rainwater and dew condensation water depending on the weather. . When the potential is measured in such a state, the lead wire 14 of the reference electrode 10 is opened, and a voltmeter is connected between the lead wire 6 from the tank bottom plate 1 to measure the potential. When the holding material 12 is dried and the potential cannot be measured, the electrolytic solution is replenished from the resin tube 13 and the potential is measured as described above. A hole 11 was made in the zinc plate 2 for measurement, but the zinc piece of the reference electrode 10 made of the same material is the zinc plate 2
Is electrically connected to Therefore, the portion of the hole 11 also forms the same corrosion protection system as the other portions. Further, even if the measuring system is short-circuited due to the load, it is the same material, so there is no adverse effect.

 An example of construction is given below.

For the tank to which the gin sheet method having the structure of Fig. 5 is applied, the zinc plate 2 is placed at a position about 50 cm from the outer circumference of the tank.
A hole with a diameter of 3 mm was opened, and a rubber sheet having a thickness of 3 mm was laid under the hole. The rubber sheet also has a 20 mmφ hole, and the hole has a 20 mmφ hole.
Of non-woven fabric. A vinyl tube with an outer diameter of 3 mm was pulled out from the hole along the groove of the rubber sheet to the outside of the tank. 2mm thick with epoxy resin lining except the hole below
A zinc plate reference electrode 10 having a width of 6 cm and a length of 60 cm was laid. Since it was just after the facility, water was replenished and the potential was measured, and the potential considered to be appropriate was measured as follows.

Immediately after OmV (converted to copper sulfate electrode −1.1V) After 2 hours + 30mV (〃 −1.07V) After one week + 39mV (〃 −1.061V) “Effect of the device” The present invention is constructed as described above. Has the effect described in.

Conventionally, because of the structure, it is not possible to insert the reference electrode, so the potential measurement in the outdoor ground tank constructed with the gin sheet method, which could not be measured with the actual equipment, was made possible with a simple structure.

Further, in the device according to the second aspect, it is possible to improve the environment in which the measurement can be easily performed even if the measurement site is dry, which is preferable.

[Brief description of drawings]

1 and 2 are explanatory views of an embodiment of the device of the present invention, a detailed plan view of essential parts, FIG. 3 is an explanatory view of a potential measurement method in a standard actual machine, and FIG. 4 is an explanatory view of measurement procedures in a laboratory. FIG. 5 is an explanatory view of the gin sheet construction method. 1 ... Bottom plate, 2 ... Zinc plate, 3 ... Reference electrode, 4 ... Voltmeter, 5 ... Basic sand, 6 ... Lead wire, 7 ... Electrolyte,
8 ... Lead wire, 9 ... Insulation material, 10 ... Plate zinc reference electrode, 11 ... Potential measurement hole, 11 '... Potential measurement hole, 12
…… Holding material, 13 …… Resin tube, 14 …… Lead wire.

Continuation of the front page (56) Reference JP-A-56-123289 (JP, A) JP-A-49-85614 (JP, A) JP-A-54-11516 (JP, A) JP-A-61-11384 (JP , A) Jikkou 56-39026 (JP, Y2)

Claims (2)

(57) [Scope of utility model registration request] 1. A reference electrode made of plate-shaped zinc is provided in a predetermined position of a laid zinc plate for a potential measuring plate which communicates with a bottom plate and an insulating material having a hole corresponding to the hole is provided to the hole. A device for measuring the electric potential of the outer surface of the bottom plate of a zinc-plated tank, wherein the hole is filled with a water retention material. 2. A potential measuring device for an outer surface of a zinc plate-laying tank bottom plate according to claim 1, wherein a resin tube for replenishing water is provided from the outside in the measurement hole.