Molten metal plating furnace, system for producing and method for producing plated product, and metal plated steel tube obtained by means of said method for producing

Abstract

[Problem] To provide: a molten metal plating furnace that can increase plating quality and work efficiency; a system for producing and method for producing a metal plated product; and a metal plated steel tube obtained by means of the method for producing. [Solution] The system for producing has at least one plating implementation unit that performs molten metal plating of a plating processing subject, and at least one plating implementation unit has a plating bath and a heating device for heating the plating bath, wherein in the heating device, an array of fuel filling openings and an array of air filling openings are formed that are facing in a manner so as to discharge air and fuel to a combustion region in common along a combustion chamber, the effective opening cross-sectional size of at least the majority of the openings of at least one of the opening arrays can be adjusted by means of an adjustment mechanism for adjusting the extent of a medium filling opening array, and when the size of both opening arrays can be adjusted, individual adjustment of the arrays is possible.

Description

BACKGROUNDTechnical Field[0001]The present invention relates to a molten metal plating furnace, especially relating to a molten metal plating furnace which is capable of diminishing variation in temperature of molten metal in a plating bath and reducing the amount of consumed gas. Further, the present invention relates to a system and a method for producing a metal-plated product capable of improving work efficiency and plating quality by incorporating the molten metal plating furnace.Related Art[0002]A molten metal plating furnace is used for dipping a metal plating treatment object into molten metal stored in a plating bath so as to apply a plating treatment to the same. For example, a molten zinc plating bath of a double wall structure constituted of an inner wall and an outer wall has been known, in which the inner wall is heated by a burner installed on the outer wall at intervals, keeping zinc stored in the plating bath inside the inner wall in a molten state (refer to Patent ...

AI Technical Summary

Benefits of technology

[0009]The inventors of the present invention found that, by employing a heating method of a new technology, which has not been applied in a molten metal plating furnace, to the molten metal plating furnace, metal can be molten without putting the jetted gas itself into high temperature as in the conventional manner, and temperature distribution of the molten metal can be uniformed, and further the gas consumption amount can be suppressed. Further, the inventors of the present invention found that, by properly incorporating the molten metal furnace into a system for producing a metal-plated product, the work efficiency of the system and plating quality can be improved, leading to the perfection of the present invention.

[0090]According to the present molten metal plating furnace, it is not a heating system that flame is emitted into a space between an iron pot and a molten metal bath for heating by heat conduction as in the conventional burner, namely, the heating system employed is that molecules generated by combustion of fuel or the like are injected so as apply kinetic energy, and the molecules storing the kinetic energy collide and vibrate so as to convert the kinetic energy to thermal energy for heating. Therefore, transfer speed of the heating system is higher than that of the heat conduction and the controlled temperature becomes easy to be controlled in a wide range. Additionally, as molten metal can be heated uniformly, a uniform plating quality can be realized. Furthermore, as heating by the direct flame of the burner is not performed, dross is hardly formed inside the metal plating bath, and rust hardly occurs. Further, also in a metal plating system into which the molten metal plating furnace (for example, a plating bath as a molten metal storage portion and a heating device to heat the plating bath) is incorporated, production capacity can be improved and higher quality of metal-plated products can be achieved due to the above effect.

Problems solved by technology

This causes a problem that a zinc deposition amount becomes less in low temperature parts, consequently, a uniform zinc plating film is not formed.

Furthermore, this plating bath heating method has problems that the temperature in the furnace becomes higher, the life of the plating bath becomes shorter, and that the costs become higher due to an increased number of combustion instruments such as burners being required in a larger number.

However, as its heating method is that the combustion gas is turned into flame and jetted into the combustion chamber from flame ports so as to heat molten zinc, the jetted gas itself needs to be high in temperature.

Therefore, progress of corrosion in the furnace cannot be suppressed.

Furthermore, a large amount of gas is needed in order to put the furnace in a high temperature state.

As described above, the conventional molten metal plating furnace has problems such as oxidation corrosion of an outer wall of the pot occurs since molten metal in the plating bath locally becomes higher in temperature which applies heavy load on the pot (plating bath) in which metal melts, and alloying and dross occur at a contact portion with the molten metal on an inner wall of the pot, and a uniform plating is difficult to be applied and gas consumption amount is large since variation occurs in temperature of the molten metal, and the like.

Similarly, when a plating system is constituted based on a conventional molten metal plating furnace, there arise problems of decreased work efficiency and the occurrence of variation in plating quality resulting from the above problems.

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