KR970704902A - Electromagnetic plug means for hot dip coating ports - Google Patents

Abstract

A hot dip coating pot (2) having a strip inlet passage (3) and electro-magnetic plugging means to prevent leakage of bath liquid from the pot through that passage, wherein: the plugging means comprises two magnetic field generators (7) disposed one on each side of the passage; each generator projects an oscillating magnetic field into the passage from at least two poles of opposite polarity that are adjacent the passage and spaced apart in the through direction of the passage; the said at least two poles of each generator are respectively in substantial alignment with the corresponding poles of the other in the transverse direction of the passage; the magnetic fields projected by the generators have flux patterns which are substantially mirror images with reference to a plane of reflection coinciding with a centre plane of the passage; and both generators operate at a frequency of more than seven kiloHertz. When no strip is present the fields combine and extend transversely of the passage. When a strip is present the fields not only plug the passage but also provide restraining forces to prevent deviation of the strip from its intended pass line.

Description

Electromagnetic plug means for hot dip coating ports

Since this is a trivial issue, I did not include the contents of the text.

Figure 2 shows a similar to the subject of Figure 1 and a magnetic field pattern established in the presence of a strip.

Claims (20)

A high temperature dip coating port comprising a strip insertion passageway and electromagnetic plugging means for preventing leakage of the liquid from the port through the passageway, wherein the plugging means comprises two magnetic field generators installed on each side of the passageway; Each of the generators emitting a magnetic field oscillating from the at least two poles of opposite polarities adjacent to the passages and separated from each other in a direction passing through the passages; Said at least two poles of each generator being substantially aligned with corresponding poles of other generators in a direction transverse to said passages; Wherein the magnetic field emitted by the generator has a substantially mirror-like line pattern with respect to a reflection plane coinciding with a center plane of the passages; And the two generators operate at a frequency of at least 3 kHz. 2. The high temperature dip coating port of claim 1, wherein the port has a bottom with a downwardly directed duct defining a strip insertion passageway. The high temperature tip coating port of claim 2, wherein the port is made of a heat resistant material. 4. The high temperature dip coating port according to claim 3, wherein the heat resistant toughening material is one of titanium stabilized aluminum, silicon carbide and boron nitride. 2. A cantilever according to claim 1, wherein each generator comprises a conductor which is tightly extended to self- 6. The high temperature dip coating port of claim 5, wherein the coil is a single winding coil. 6. The high temperature dip coating port of claim 5, wherein the conductor is tubular and the terminal is adapted for connection with a source of coolant that provides a flow of coolant through the interior of the conductor. 2. The hot tip coating port of claim 1, wherein each of the meter generators comprises a feed coil wound on a magnetic core having an end face toward the passageway, the end face comprising the pole of the generator. 9. The hot dip coating port of claim 8, wherein the core is G-shaped and has one end surface smaller than the other. 10. The apparatus of claim 9, wherein the generator comprises a non-ferrous electrically conductive shield adapted to confine the magnetic field and positioned to increase the ratio of the total magnetic field produced by the energy supply coil and emerging from the end face of the core High temperature dip coating port. 9. The high temperature dip coating port of claim 8, wherein each side of the passageway provides a barrier between the molten metal of the bath and the top of the generator by raising non-ferrous, heat resistant, insulating side plates side by side. The high temperature dip coating port of claim 8, wherein the core is made of a low loss material having high permeability and high saturation magnetization properties. 13. The hot dip coating port of claim 12, wherein the material is one of high density ferrite, magnetic metal glass and iron powder. The high temperature dip coating port according to claim 1, wherein the distance between at least two gaps in the passageway passing direction is in the range of 2 to 10 times the gap width on the strip to be coated and on one side of the passageway. The high temperature dip coating port according to claim 8, wherein each of the power feeding coils is a multi filament coil of not more than 10 windings. 11. The hot dip coating port of claim 10, wherein said shield is forced cooling. The high temperature dip coating port of claim 1, wherein the frequency is in the range of 7 kHz to 100 kHz. 18. A method according to any one of the preceding claims, wherein the polarity of the generator combines the emitted magnetic field during operation in the absence of a strip to be coated, Wherein the high-temperature dip coating port extends across the entire surface of the substrate. A high temperature dip coating port as described with reference to any of Figures 1 to 4 or 5 to 7. An apparatus for continuously hot dip coating a metal strip comprising a coating port according to claim 1 in a metal coating. ※ Note: It is disclosed by the original application.