JPH08364Y2 - Metal tube surface treatment equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus for performing a metal pipe surface treatment in two steps using a chemical conversion treatment liquid containing inorganic ions in the chemical conversion treatment of a metal pipe surface.

[Prior Art] Metal pipes with plastic coatings are mainly used as pipelines for transporting gas and crude oil and offshore structures, and most of those applications are for 40 to 50 years under severe corrosive environmental conditions. Long-term durability is required. In order to satisfy this requirement, as is well known, it is indispensable to subject the surface of the metal tube to an appropriate pretreatment before the plastic coating.

There are various surface treatment methods depending on the use of the metal tube, required characteristics, etc., but a method using a chemical conversion treatment liquid containing chromium ions is generally used. The apparatus for carrying out this method, as described in JP-A-62-294183, sprays a treatment liquid ejected from a nozzle onto the blasted metal surface to remove dust on the metal tube surface and apply the treatment liquid. Simultaneously, and then the coating amount is made uniform by an ironing device. Here, in the case of only coating, in addition to spraying with a nozzle, various methods such as a roll coater method and an appropriate amount dropping method can be considered. Is reused immediately after removing dust contained in the liquid with a magnetic separator or the like.

[Problems to be solved by the device]

The apparatus described in JP-A-62-294183, while basically cleaning the surface of the metal tube with a chemical conversion treatment liquid,
A chemical conversion treatment film is formed by the chemical conversion treatment liquid remaining on the surface of the metal tube. In this device, the basis weight of the chemical conversion treatment liquid may depend on the conditions under which the chemical conversion treatment liquid is sprayed for dust removal and cleaning of the metal tube surface. This is because if the pressure for spraying the chemical conversion treatment liquid is increased to effectively remove dust and clean the surface of the metal tube, the amount of the chemical conversion treatment liquid sprayed will also increase. As a result, the basis weight of the chemical conversion treatment liquid is considered to increase.

Therefore, it may be difficult to secure the coating weight of the chemical conversion treatment liquid that exerts a sufficient chemical conversion treatment effect while performing effective dust removal and cleaning.

On the other hand, normally, as a pre-process of the chemical conversion treatment, air blow on the surface of the metal tube or suction of the surface of the metal tube by a vacuum device is performed to remove adhering substances such as blast powder, but this alone cannot achieve sufficient dust removal. Therefore,
With the roll coater method or the appropriate amount dropping method, in the one-step chemical conversion treatment device intended only for coating, since the chemical conversion treatment is performed on the surface of the metal tube where sufficient dust removal has not been achieved, the chemical conversion treatment liquid has In some cases, it may be difficult to fully exhibit the original performance.

The present invention focuses on the above-mentioned problems in the prior art, and provides a metal pipe surface treatment device capable of effectively cleaning the metal pipe surface and always applying the chemical conversion treatment liquid in an appropriate basis weight. The purpose is to do.

[Means for solving the problem]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention.
Hereinafter, the first chemical conversion treatment liquid and the second chemical conversion treatment liquid will be referred to as a cleaning liquid and a coating liquid, respectively.

In FIG. 1, the first chemical conversion treatment apparatus A is the apparatus at the upper right of the figure, and includes two cleaning liquid supply tanks 1, a cleaning liquid supply pump 2 for spraying the cleaning liquid onto the metal pipe 3, and the rest of the sprayed cleaning liquid. It comprises a cleaning liquid recovery tank 4 for recovering the non-adhered cleaning liquid, and a cleaning liquid recovery pump 6 for recovering the recovered non-adhered cleaning liquid to the cleaning liquid supply tank 1 via a filter 5.

The second chemical conversion treatment apparatus B is the apparatus at the upper left of FIG. 1, and includes two coating solution supply tanks 7, a coating solution supply pump 8 for applying the coating solution to the cleaned metal tube 3, and a coating solution supply pump 8. Coating liquid recovery tank 16 for recovering the remaining non-adhered coating liquid of the applied coating liquid, and a coating liquid recovery pump for transferring the recovered non-adhered coating liquid to coating liquid regenerating tank 9 via filter 5. Made of 10.

The apparatus on the lower side of FIG. 1 is a regeneration processing apparatus C, and a cleaning liquid regeneration tank 11 for collecting the contaminated and deteriorated cleaning liquid of the cleaning supply tank 1 via a cleaning liquid transfer pump 12.
The cleaning liquid regeneration pump 13 for transferring the contaminated and deteriorated cleaning liquid accumulated in the cleaning liquid regeneration tank 11 and the contaminants transferred through the filter 5 by the cleaning liquid regeneration pump 13 and all the ions in the deteriorated cleaning liquid are removed. An ion exchange device 14 for forming pure water, a pure water storage tank 15 for collecting a cleaning liquid which has become pure water by passing through the ion exchange device 14, the pure water and the coating liquid regeneration tank 9 A cleaning liquid mixing tank 17 that mixes the accumulated coating liquid and becomes a cleaning liquid again, a pure water pump 20 for transferring the pure water to the cleaning liquid mixing tank 17, and a coating liquid accumulated in the coating liquid regenerating tank 9. And a cleaning liquid preparation pump 19 for transferring the cleaning liquid prepared in the cleaning liquid preparation tank 17 to the cleaning liquid supply tank 1.

In this configuration, the first chemical conversion treatment device A (cleaning liquid supply / recovery device) may have only one cleaning liquid supply tank 1, and the second chemical conversion treatment device B (coating liquid supply / recovery device) also has the coating liquid supply tank 7. You can choose one.

Now, regarding the characteristic part of the apparatus of the present invention, the header for spraying the cleaning liquid of the first chemical conversion treatment apparatus A is the cleaning header 21 and the second chemical conversion treatment apparatus B in the above-mentioned configuration.
The coating header 22 is a header for applying the coating liquid.

The cleaning header 21 may be a ring-shaped one as described in JP-A-62-294183 or a substitute thereof, but in any case, it has a structure capable of removing foreign matter adhering to the surface of the metal tube. Is desirable. Further, as the coating header 22, a roll coater system or a proper amount dropping system header can be used.

[Action]

Next, a series of processing liquid transfer mechanisms relating to the metal pipe surface processing apparatus of the present invention will be described below.

First, the cleaning liquid having a low concentration, which is contained in the cleaning liquid supply tank 1, is supplied to the metal pipe 3 by the cleaning liquid supply pump 2 for cleaning, and the unattached cleaning liquid is passed through the filter 5 and the cleaning liquid recovery pump 6. It is sent back to the cleaning liquid supply tank 1 and used repeatedly until the cleaning liquid becomes contaminated and deteriorates. Meanwhile, in the second chemical conversion treatment apparatus B, which is the coating liquid supply and recovery device, the coating liquid supply tank 7 is attached to the cleaned metal pipe 3.
The coating liquid transferred from is applied via the coating liquid supply pump 8. The coating liquid used for coating is used only once, and the non-adhered coating liquid is collected in the coating liquid collecting tank 16 and sent to the coating liquid regenerating tank 9 via the filter 5 and the coating liquid collecting pump 10. To be

Next, these unadhered coating solutions and a cleaning solution which has been used repeatedly until it is contaminated and deteriorated as described above and then ion-exchanged to be a pure cleaning solution are prepared and used again as a cleaning solution. In the regeneration processing apparatus C, the deteriorated cleaning liquid is sent to the cleaning liquid regeneration tank 11 by the cleaning liquid transfer pump 12. The cleaning liquid in the cleaning liquid regeneration tank 11 is further separated by the cleaning liquid regeneration pump 13 through the filter 5 and the ion exchange device 14 into pure water and a precipitate, and the pure water is stored in the pure water storage tank 15. Here, when the liquid stored in the pure water storage tank 15 is not sufficiently ion-exchanged and cannot be regarded as pure water, the pure water pump 20 of the liquid sends it to the cleaning liquid regeneration tank 11. , Cleaning liquid regeneration pump again
It is sent to the pure water storage tank 15 by the filter 13 and the ion exchange device 14 by the filter 13.

The pure water generated as described above is sent from the pure water storage tank 15 to the cleaning liquid preparation tank 17 by the pure pump 20. In the cleaning liquid preparation tank 17, the pure water and the non-adhered coating liquid sent from the coating liquid regeneration tank 9 via the coating liquid regeneration pump 18 are mixed, and again as a cleaning liquid via the cleaning liquid preparation pump 19. It is sent to the cleaning liquid supply tank 1.

In the series of processing liquid transfer mechanism as described above, the metal pipe 3
The cleaning liquid is supplied to the cleaning header 21 through the cleaning header 21. Here, the conditions for supplying the cleaning liquid are as described in JP-A-62-294.
The conditions described in Japanese Patent No. 183 may be used, but in consideration of the second-stage chemical conversion treatment and the prevention of scattering of the mist of the cleaning liquid, it is desirable to set the minimum spraying pressure at which dust removal of the metal tube 3 is possible. Next, supply of the coating liquid to the metal tube 3 is performed by the coating header.
In this case, before the coating liquid supplied to the metal tube 3 is dried, a brush, urethane, or the like is used to make the unit weight of the coating liquid uniform. If it is necessary to make the basis weight of the cleaning liquid uniform, the same method can be applied after supplying the cleaning liquid.

[Effect of device]

Since the present invention is an apparatus that performs the metal pipe surface treatment with the chemical conversion treatment liquid containing inorganic ions in two stages as described above, the effect of the chemical conversion treatment on the metal pipe surface is independent of the spraying condition of the cleaning liquid. Can be fully exerted.

[Brief description of drawings]

 FIG. 1 is a diagram showing the construction of the device of the present invention. A: First chemical conversion treatment device, B: Second chemical conversion treatment device C: Regeneration treatment device 1: Cleaning liquid supply tank, 2: Cleaning liquid supply pump 3: Metal tube, 4: Cleaning liquid recovery tank 5: Filter, 6: Cleaning liquid recovery Pump 7: coating liquid supply tank, 8: coating liquid supply pump 9: coating liquid regeneration tank, 10: coating liquid recovery pump 11: cleaning liquid regeneration tank, 12: cleaning liquid transfer pump 13: cleaning liquid regeneration pump, 14: ion exchange device 15 : Pure water storage tank, 16: Coating liquid recovery tank 17: Cleaning liquid preparation tank, 18: Coating liquid regeneration pump 19: Cleaning liquid preparation pump, 20: Pure water pump 21: Cleaning header, 22: Coating header

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kaoru Umezu Inventor, 1 Kimitsu, Kimitsu City, Chiba Nippon Steel Stock Co., Ltd. Inside the Kimitsu Works, Kaisha (56) Reference JP-A-55-21556 (JP, A) JP Sho 62-294183 (JP, A) JP-A-63-128199 (JP, A) JP-B 41-21973 (JP, B1) JP-B 55-3428 (JP, B2)

Claims (2)

[Scope of utility model registration request] 1. A metal pipe surface treatment apparatus for subjecting a surface of a metal pipe, which has been blasted, to a base treatment using a chemical conversion treatment liquid containing inorganic ions in a step of applying a plastic coating on the surface of the metal pipe. , The surface of the metal tube is treated with the first chemical conversion treatment liquid having an appropriate concentration, and then the metal pipe surface is treated again with the second chemical conversion treatment liquid having an appropriate concentration in the second step. When performing a so-called two-step surface treatment, a spray header by a spraying method in the first step and a brush that makes the amount of the treatment solution uniform after dropping an appropriate amount of the second chemical conversion treatment solution in the second step A metal pipe surface treatment device that is characterized by combining urethane and urethane. 2. A metal pipe surface treatment apparatus for subjecting a blasted metal pipe surface to a base treatment using a chemical conversion treatment liquid containing an inorganic ion in a continuous transfer line for applying a plastic coating to the surface of the metal pipe. In the step, the metal pipe surface is treated with the first chemical conversion treatment liquid having an appropriately adjusted concentration, and then in the second step, the metal pipe surface is again treated with the second chemical conversion treatment liquid having an appropriately adjusted concentration. When continuously applying a so-called two-step surface treatment, a spray header by a spraying method in the first step and an appropriate amount of the second chemical conversion treatment solution in the second step are dropped and then the adhesion amount of the treatment solution A metal pipe surface treatment device characterized by combining a brush, urethane, etc. to make the uniform.