Specialized metallurgical processes – compositions for use therei – Processes – Electrothermic processes
Patent
1997-07-08
1999-04-27
Valentine, Donald R.
Specialized metallurgical processes, compositions for use therei
Processes
Electrothermic processes
75 1067, 118405, 118623, 427431, 427433, C22B 400, B05C 302, B05C 502, B05D 118
Patent
active
058976833
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to a method and an apparatus for holding molten metal in a container and is specifically concerned with a molten metal plating apparatus using the holding apparatus.
BACKGROUND OF THE INVENTION
In facilities for plating by passing a material to be plated through a bath of molten metal such as zinc or aluminum, a conductive liquid, the molten metal is held by a method as described in Japanese Laid-Open Patent Publication No. 356/92. In this method an opening portion is provided at the bottom of an aerial pot from a material poorly wettable by molten metal, and utilizes the surface tension of the molten metal to hold the molten metal inside the aerial pot. This method is limited in increasing the height of the molten metal that can be held.
To achieve an increased height of molten metal which can be held in a container Japanese Laid-Open Patent Publication No. 109148/88 discloses a technique of providing a pressure chamber for accommodating a gas under the container storing molten metal. This technique involves a pressure chamber containing gas connected to an opening at the bottom of the molten metal container, and raising the gas pressure inside the pressure chamber, thereby increasing the height of the molten metal held in the molten metal container. The technology disclosed in this publication, however, has the disadvantage that even when the pressure (gravitational) of the molten metal at the opening balances statically with the gas pressure inside the pressure chamber, the difference in density between the gas and the molten metal causes the gas to penetrate the molten metal as bubbles and go up through the molten metal.
To obtain a plating of satisfactory quality by passing a material to be plated through molten metal, it is desired that the height of the molten metal be kept high and constant, and avoid gas bubbles in the molten metal.
An object of the present invention is to enable molten metal to be held at a predetermined height in a container with an opened bottom.
Another object of the invention is to prevent the formation of gas bubbles in molten metal.
Still another object of the invention is to produce a plating of satisfactory quality by hot dipping.
DISCLOSURE OF THE INVENTION
The present invention concerns an apparatus for holding molten metal, which comprises a magnetic field generating means for generating a horizontal magnetic field in a lower part of molten metal in a container to hold the molten metal in the container by an electromagnetic force; and a conductive block constructed such that eddy currents induced in the molten metal partly flow outside the molten metal. The conductive block is composed of block portions provided at sites where the horizontal magnetic field generated by the magnetic field generating means abruptly changes, and a connecting portion for connecting together the block portions outside the molten metal.
According to this invention, molten metal in the container is held by an electromagnetic force from a horizontal magnetic field generated by a magnetic field generating means. Eddy currents induced in the molten metal are partly guided by a conductive block to flow outside the molten metal. Thus, the amount of electric currents flowing in the molten metal decreases, thereby diminishing a downward force acting on the molten metal. The decrease in the amount of electric currents flowing in the molten metal can also suppress the rise in the temperature of the molten metal due to Joule heat. Therefore, the height of the molten metal can be maintained higher than when the conductive block is absent.
The present invention also pertains to an apparatus for holding molten metal, characterized in that a pressure chamber for holding a gas for imparting pressure to the bottom surface of the molten metal is provided under the container.
The present invention also concerns an apparatus for holding molten metal, which comprises a container for accommodating molten metal, the container having an opening for passage of a m
REFERENCES:
patent: 5071471 (1991-12-01), Miki et al.
patent: 5106411 (1992-04-01), Miki et al.
patent: 5662969 (1997-09-01), Ling
patent: 5665437 (1997-09-01), Frommann et al.
Hashimoto Ritsuo
Hukada Yasuo
Kato Chiaki
Kawata Noriyuki
Matsukawa Toshitane
Kawasaki Steel Corporation
Mitsubishi Jukogyo Kabushiki Kaisha
Valentine Donald R.
LandOfFree
Method and apparatus for holding molten metal does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for holding molten metal, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for holding molten metal will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-683478