Hot dip coating apparatus and hot dip coating method

Abstract

The present invention relates to a hot dip coating apparatus for providing a metal coating on a moving metal sheet, including a liquid bath of metal coating material in use, wherein the metal coating material is provided on the moving metal sheet in use, including for A vessel for a liquid bath, at least guide or sink rollers positioned in the vessel at the level of the surface of the liquid bath to guide the moving metal sheet through the bath and an air knife positioned above the liquid bath in use, the air knife having an outlet to The wiping gas is projected onto a metal coating provided on a metal sheet which, in use, passes along the air knife, and wherein at least one support roller is provided which, in use, affects the metal at least at the location of the air knife The shape of the sheet in its width direction. According to the present invention, in use, at least one support roller is placed above the surface level of the liquid bath so that it operates on the metal sheet before it enters the liquid bath. The invention also relates to a method of using the hot dip coating device.

Description

technical field [0001] The present invention relates to a hot dip coating apparatus for providing a metal coating on a moving metal sheet, including a liquid bath of metal coating material in use, wherein the metal coating material is provided on the moving metal sheet in use, including using A vessel in the liquid bath, at least guide or sink rollers positioned in the vessel below the surface level of the liquid bath to guide the moving metal sheet through the liquid bath and an air knife positioned above the liquid bath in use, the air knife having an outlet to project wiping gas onto a metal coating provided on a metal sheet which, in use, passes along the air knife, and wherein at least one back-up roller is provided, the at least one back-up roller and the guide or The sink rollers in use influence the shape of the metal sheet in the width direction thereof, at least at the location of the air knife. The invention also relates to a method of coating a moving metal sheet....

AI Technical Summary

Problems solved by technology

This not only adversely affects the operating costs of the hot dip coating plant, but also adversely affects the productivity of the plant due to the unavoidable loss of production time due to the required maintenance

[0009] Another problem with one or more support rollers known in liquid metal baths is that wet frictional contact of the rollers with the moving metal sheet in the liquid bath causes the rollers to rotate, which leads to damage due to slippage between the roller and the moving metal sheet possible sheet metal damage

Also, from design considerations, the manner in which the one or more support rollers are driven creates a limitation on the processing speed of the device, since the speed of the moving metal sheet is limited to the sliding edge points

[0010] Another problem with submerged one or more support rolls is that the flow of liquid metal in the liquid metal bath is affected by the rotating rolls, and the flow pattern within the liquid metal bath can cause impurities in the bath to deposit on the surface of the moving metal sheet superior

[0011] Finally, there are limitations in the design of known coating devices related to the required structural support for one or more backup rolls, which are usually arranged above the bath level, where the space due to the air knife should Restricted near the surface level of the metal bath

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