JPH07188955A - Method for preventing corrosion of member set in corrosive fluid - Google Patents

Abstract

PURPOSE:To improve the corrosion resistance of a member set in a corrosive fluid by coating the member with a corrosion-resistant resin. CONSTITUTION:The corrosion of a nozzle 10 welded onto a feed pipe 9 is prevented in an alkylation device, for example. In the case, a tube 11 consisting of a heat-contractible polyfluoroethylene resin is put on the nozzle 10 from its upper part to cover the nozzle 10. The tube is heated by a burner 12, and the tube 11 is contracted and firmly attached to the nozzle 10. Consequently, the corrosion resistance of the nozzle 10 is improved, and the inspection labor cost and repairing cost are reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is disposed in a corrosive fluid in an alkylation device, a waste sulfuric acid regenerating device, a flue gas desulfurizing device, a deodorizing device, an atmospheric distillation device, an amine regenerating device, an HPC regenerating device and the like. The present invention relates to a method of preventing corrosion of a member.

[0002]

2. Description of the Related Art Alkylation equipment, waste sulfuric acid regeneration equipment, flue gas desulfurization equipment, deodorization equipment, atmospheric distillation equipment, amine regeneration equipment, HPC regeneration equipment, etc. are subject to corrosion in the product process in the tower tank such as a reaction tower. We handle sexual fluids. Therefore, in tower tanks such as reaction towers, members such as nozzles, pipes, ladders, and thermowells are arranged in a corrosive fluid.
Since these members are constantly immersed in corrosive fluids, their anticorrosion measures have become an important issue.
It was common to manufacture components from stainless steel.

[0003]

However, stainless steel members do not have sufficient anticorrosion performance against corrosive fluids, especially sulfuric acid. For example, in an olefin nozzle of an alkylation apparatus, corrosion by sulfuric acid is large, and periodic inspection is required. After visually inspecting all 350 nozzles,
There is a problem in that more than this must be replaced, and the inspection labor and repair cost increase.

The present invention solves the above problems and provides a corrosion preventing method capable of improving the corrosion preventing performance of a member disposed in a corrosive fluid and reducing the inspection labor and repair cost thereof. The purpose is to do.

[0005]

Therefore, a method of preventing corrosion of a member arranged in a corrosive fluid according to the present invention is characterized in that a member arranged in a corrosive fluid is coated with a corrosion resistant resin. . Examples of the corrosion-resistant resin include polyfluoroethylene-based resin, polyolefin-based resin, polyphenylene sulfide-based resin, and polyvinylidene fluoride-based resin. Among these, polyfluorinated ethylene resins are preferable. Further, as a method for coating the member with these resins, a heat treatment method for coating the periphery of the member by utilizing heat shrinkability due to heating or a CVD (Chemical Vapor Dep
osition) method, PVD method, vapor deposition method, spray method, coating method and the like. Among them, the heat treatment method is preferable from the viewpoint of operability.

[0006]

In the present invention, the heat-shrinkable polyfluoroethylene-based resin has a high anticorrosive performance against corrosive fluids such as sulfuric acid,
Even if many irregularities are formed on the peripheral surface of the member, the heat-shrinkable polyfluorinated ethylene-based resin is easy to follow changes in its shape and has excellent adhesion, so that corrosive fluid between the member and the tube Penetration can be prevented and the anticorrosion performance of the member can be improved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is an overall configuration diagram of an alkylation device to which the present invention is applied.

The inside of the reaction tower 1 is partitioned by a plurality of partition plates 2 to form a plurality of reaction chambers 3 and a separation chamber 4. A raw material supply device 5 and a stirring device 6 are arranged in each reaction chamber 3, and a separation device 7 is arranged in the separation chamber 4. Then, while sulfuric acid is supplied from one side of the reaction tower 1,
A raw material (naphtha) is supplied to each raw material supply device 5, the raw material reacts with sulfuric acid in each reaction chamber 3 to be reformed, and the separation device 7
The sulfuric acid and the reformed product are separated and discharged by.

FIG. 2 is a perspective view of the raw material supply device of FIG. 3, in which the raw material supply device 3 is welded to the main pipe 8, an annular supply pipe 9 connected to the main pipe 8, and a large number of parts welded to the supply pipe 9. Nozzle 10. A stirrer 6 is arranged in the annular supply pipe 9, and the raw material injected from the nozzle 10
It is configured to mix with sulfuric acid supplied from the front chamber via the upper portion of the partition plate 2. In addition, 11 is an isobutane injection device.

FIG. 1 is a diagram showing an embodiment of a method for preventing corrosion of a member arranged in a corrosive fluid according to the present invention. Supply pipe 9
When the tube 11 made of heat-shrinkable polyfluoroethylene resin is inserted from the upper portion of the nozzle 10 welded onto the nozzle 10 to cover the periphery of the nozzle 10 and heated by the burner 12, the tube 11 contracts and the It is fixed in close contact with the surroundings. The heat-shrinkable polyfluoroethylene-based resin has a high anticorrosive performance against a corrosive fluid such as sulfuric acid, and many irregularities are formed on the peripheral surface of the nozzle 10. Since the resin is easy to follow the change of its shape and has excellent adhesiveness, the nozzle 10 and the tube 11
The penetration of the corrosive fluid into the space can be prevented, and the anticorrosion performance of the nozzle can be improved.

Although the nozzle of the alkylation device has been described in the above embodiments, the present invention is not limited to this, and the alkylation device, the waste sulfuric acid regenerating device, the flue gas desulfurizing device, the deodorizing device, and the atmospheric distillation are not limited thereto. It is also applicable to members such as pipes, ladders, thermowells, etc. arranged in a corrosive fluid in a device, an amine regenerator, an HPC regenerator, and the like.

[0012]

As is apparent from the above description, according to the present invention, it is possible to improve the anticorrosion performance of the member arranged in the corrosive fluid, and reduce the inspection labor and the repair cost.

[Brief description of drawings]

FIG. 1 is a diagram showing one embodiment of a method of preventing corrosion of a member arranged in a corrosive fluid of the present invention.

FIG. 2 is a perspective view of the raw material supply device of FIG.

FIG. 3 is an overall configuration diagram of an alkylation device to which the present invention is applied.

[Explanation of symbols]

 10 ... Nozzle, 11 ... Tube

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area C09D 181/02 PML

Claims (1)

[Claims] 1. A method for preventing corrosion of a member arranged in a corrosive fluid, characterized by coating a member arranged in a corrosive fluid with a corrosion resistant resin.