Apparatus and method for reducing spangle in galvanized products

Claim 1

An apparatus for controlling coating thickness on a substrate and reducing spangle as the substrate moves along a feed path, said apparatus comprising: an air knife located to discharge pressurized air generally perpendicular to said substrate to screed coating material from said substrate leaving a coating of desired thickness and distribution; and means including a nozzle for discharging a gas and liquid mixture toward said substrate to cool the coating material after said air knife screeds said coating material and thereby reduce spangle; said nozzle being positioned to discharge said gas and liquid mixture toward said substrate in proximity to the location at which air from said air knife impinges on said substrate so that said air will materially affect the flow of said gas and liquid mixture.

Claim 2

An apparatus for controlling coating thickness on a substrate and reducing spangle as the substrate moves along a feed path, said apparatus comprising: an air knife located to discharge pressurized air generally perpendicular to said substrate to screed coating material from said substrate leaving a coating of desired thickness and distribution; and means including a nozzle for discharging a gas and liquid mixture toward said substrate to cool the coating material after said air knife screeds said coating material and thereby reduce spangle; said nozzle being positioned to discharge said gas and liquid mixture toward said substrate in proximity to the location at which air from said air knife impinges on said substrate so that said air will materially affect the flow of said gas and liquid mixture.

Claim 4

An apparatus for applying a galvanizing coating of molten metal to a moving strip by passing the strip through the molten metal and for reducing spangle, said apparatus comprising: an air knife extending across a path along which the coated strip is moved, said knife constructed and arranged to apply a flow of air substantially perpendicular to the strip to control the thickness and distribution of the coating; and means for applying an air and water mixture to the coated strip at an angle to the path adjacent and slightly downstream of the location of air impingement of the air knife where the flow from the air knife will carry the mixture in the direction of the strip movement.

Claim 5

An apparatus for applying a galvanizing coating of molten metal to a moving strip by passing the strip through the molten metal and for reducing spangle, said apparatus comprising: an air knife extending across a path along which the coated strip is moved, said knife constructed and arranged to apply a flow of air substantially perpendicular to the strip to control the thickness and distribution of the coating; and means for applying an air and water mixture to the coated strip at an angle to the path adjacent and slightly downstream of the location of air impingement of the air knife where the flow from the air knife will carry the mixture in the direction of the strip movement.

Claim 11

An apparatus for screeding excess molten metallic coating material from a substrate continuously moving along a feed path and for cooling said coating material, comprising: a plurality of air knives discharging pressurized air to impinge against said substrate, to remove excess material and to leave a coating of desired thickness and distribution; an array of cooling nozzles associated with each air knife, for reducing spangle, each array located downstream along the feed path with respect to its associated air knife, each cooling nozzle in an array spraying a gas and liquid mixture substantially in parallel paths with respect to the other nozzles in the array, each array positioned to direct its spray at the approximate location at which the air from its associated air knife impinges the substrate, said discharged air from said air knife materially affecting the flow of each spray.

Claim 12

An apparatus for screeding excess molten metallic coating material from a substrate continuously moving along a feed path and for cooling said coating material, comprising: a plurality of air knives discharging pressurized air to impinge against said substrate, to remove excess material and to leave a coating of desired thickness and distribution; an array of cooling nozzles associated with each air knife, for reducing spangle, each array located downstream along the feed path with respect to its associated air knife, each cooling nozzle in an array spraying a gas and liquid mixture substantially in parallel paths with respect to the other nozzles in the array, each array positioned to direct its spray at the approximate location at which the air from its associated air knife impinges the substrate, said discharged air from said air knife materially affecting the flow of each spray.

Claim 16

An apparatus for screeding excess coating material from a sheet substrate continuously moving along a feed path and cooling said coating material, said apparatus comprising: air knives, at least one located on each side of said substrate for removing excess coating material from each side of said substrate by discharging air under pressure and for leaving a coating of desired thickness and distribution on each side of said substrate; a plurality of linear arrays of cooling nozzles, each nozzle spraying a gas and liquid mixture, each air knife having a corresponding array, each array positioned to direct its spray at an approximate location where the air from the corresponding air knife impinges the substrate, said air from said air knives materially affecting the spray from the corresponding array of cooling nozzles.

Claim 17

An apparatus for screeding excess coating material from a sheet substrate continuously moving along a feed path and cooling said coating material, said apparatus comprising: air knives, at least one located on each side of said substrate for removing excess coating material from each side of said substrate by discharging air under pressure and for leaving a coating of desired thickness and distribution on each side of said substrate; a plurality of linear arrays of cooling nozzles, each nozzle spraying a gas and liquid mixture, each air knife having a corresponding array, each array positioned to direct its spray at an approximate location where the air from the corresponding air knife impinges the substrate, said air from said air knives materially affecting the spray from the corresponding array of cooling nozzles.

Claim 19

A method of coating and cooling a substrate in a manner to reduce spangle, the method comprising steps of: coating a substrate with a molten coating material, screeding the coating material on the substrate by impinging air from an air knife thereagainst, and directing a gas and liquid spray directly toward the coated substrate at a location sufficiently close to where air from said air knife has impinged the coated substrate to have the air from the air knife materially affect the spray flow.

Claim 20

A method of coating and cooling a substrate in a manner to reduce spangle, the method comprising steps of: coating a substrate with a molten coating material, screeding the coating material on the substrate by impinging air from an air knife thereagainst, and directing a gas and liquid spray directly toward the coated substrate at a location sufficiently close to where air from said air knife has impinged the coated substrate to have the air from the air knife materially affect the spray flow.

Claim 21

A method of coating and cooling a substrate in a manner to reduce spangle, the method comprising the steps of: coating a substrate with a molten coating material, screeding the coating material on the substrate by impinging air from an air knife thereagainst, and directing a cooling mixture spray toward the coated substrate at a location sufficiently close to where said air knife has screeded the coating material so that the cooling mixture will be forced to flow along the substrate surface.

Claim 22

A method of coating and cooling a substrate in a manner to reduce spangle, the method comprising the steps of: coating a substrate with a molten coating material, screeding the coating material on the substrate by impinging air from an air knife thereagainst, and directing a cooling mixture spray toward the coated substrate at a location sufficiently close to where said air knife has screeded the coating material so that the cooling mixture will be forced to flow along the substrate surface.

Claim 23

A method of galvanizing a metal substrate as the substrate moves along a feed path comprising the steps of: (a) coating the substrate with a molten coating material, (b) directing an air flow from an air knife perpendicular to and across the width of the coated substrate; and (c) directing a flow of air and water mixture from a common nozzle at an angle to said substrate, said mixture directed at the proximate location the air flow from the air knife impinges the substrate so the air from the air knife materially affects the mixture flow.

Claim 24

A method of galvanizing a metal substrate as the substrate moves along a feed path comprising the steps of: (a) coating the substrate with a molten coating material, (b) directing an air flow from an air knife perpendicular to and across the width of the coated substrate; and (c) directing a flow of air and water mixture from a common nozzle at an angle to said substrate, said mixture directed at the proximate location the air flow from the air knife impinges the substrate so the air from the air knife materially affects the mixture flow.

Claim 26

A method of coating and cooling an elongated metal substrate with a galvanizing material in a manner to inhibit spangle in the coating, the steps comprising: coating the substrate with a molten metal, screeding the molten metal on the substrate by directing an air flow from an air knife against the coated surface across the width of the surface, and directing a mixed gas and liquid flow from a common nozzle at an angle to said substrate from a location downstream from the location at which the air flow from the air knife originates, said mixture directed at the proximate location the air flow from the air knife impinges the substrate so the air from the air knife materially affects the mixture flow.

Claim 27

A method of coating and cooling an elongated metal substrate with a galvanizing material in a manner to inhibit spangle in the coating, the steps comprising: coating the substrate with a molten metal, screeding the molten metal on the substrate by directing an air flow from an air knife against the coated surface across the width of the surface, and directing a mixed gas and liquid flow from a common nozzle at an angle to said substrate from a location downstream from the location at which the air flow from the air knife originates, said mixture directed at the proximate location the air flow from the air knife impinges the substrate so the air from the air knife materially affects the mixture flow.