Device for producing coated steel sheet and method for producing coated steel sheet

Patent metadata

Field	Value
Publication number	US-9868136-B2
Application number	US-201214238535-A
Country	US
Kind code	B2
Filing date	Mar 14, 2012
Priority date	Mar 14, 2012
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

A device for producing a coated steel sheet includes: a blowing-off unit which sprays a gas onto and remove an excessive coating that accumulates along a side edge of a steel sheet that threads along one direction; and a coating-collection unit which collects the excessive coating removed by the blowing-off unit. The blowing-off unit includes a spray nozzle and a gas supply member. The coating-collection unit includes a duct and a coating container. In a case where the duct is seen in a plan view, an outlet thereof is disposed to fit in and overlap an inside of an opening of the coating container, and in a case where the duct is seen in a side view, a gap is provided between the outlet and the opening of the coating container.

First claim

The invention claimed is:

1. A device for producing a coated steel sheet, comprising:
a blowing-off unit which sprays a gas onto and removes excessive coating that accumulates along a first side edge of a steel sheet that threads along one direction; and
a coating-collection unit which collects the excessive coating removed by the blowing-off unit,
wherein the blowing-off unit comprises:
a first spray nozzle extending from a gas supply member, the first spray nozzle directed in a direction from an inside to an outside in a sheet-width direction of the steel sheet and directed toward the first side edge, and
the gas supply member supplying the compressed gas to the first spray nozzle,
wherein the coating-collection unit includes a duct having an inlet that receives the excessive coating and an outlet that discharges the received excessive coating, and a coating container having an opening that receives the excessive coating discharged from the outlet, the container being below the inlet to the duct,
wherein, in a case where the duct is seen in a plan view, the outlet is disposed to fit in and overlap an inside of the opening of the coating container, and in a case where the duct is seen in a side view, a gap is provided between the outlet and the opening of the coating container and the gap is 60 mm to 100 mm,
wherein an opening area of the inlet of the duct is larger than an opening area of the outlet of the duct, and an opening area of the opening of the coating container is larger than the opening area of the outlet of the duct,
wherein the inlet of the duct is located below a surface of the steel sheet and is positioned to be oblique with respect to the surface of the steel sheet and the sheet threading direction of the steel sheet, and the inlet of the duct faces a discharge direction of the compressed gas that is discharged from the first spray nozzle to receive the excessive coating which is blew-off from the surface of the steel sheet,
wherein an angle β of a center axis of the first spray nozzle and the surface of the steel sheet is between 30 and 60 degrees,
wherein an angle α of a projection of the first spray nozzle onto the surface of the steel sheet in a direction perpendicular to the surface of the steel sheet and the first side edge of the steel sheet is between 30 and 60 degrees,
wherein a length d along the center axis of the first spray nozzle between an end of the first spray nozzle and the surface of the steel sheet is between 10 mm and 55 mm, and

wherein the discharge direction is oblique with respect to all of the sheet threading direction of the steel sheet, a direction perpendicular to the surface of the steel sheet and a width direction of the steel sheet.

2. The device for producing a coated steel sheet according to claim 1 , wherein a high-viscosity coating is applied to the steel sheet using a coating curtain and has a viscosity is 700 mPa·sec to 2000 mPa·sec.

3. The device for producing a coated steel sheet according to claim 2 , wherein the blowing-off unit is adjusted so that a discharge flow rate of the gas discharged from the first spray nozzle is 12 m 3 /h or more and 20 m 3 /h or less, a discharge flow velocity of the gas discharged from the first spray nozzle at a position of 5 mm from a tip end of the first spray nozzle in a discharge direction when seen along an extension line of a center axis line of the first spray nozzle is 420 m/s or more and 520 m/s or less, and a discharge flow velocity of the gas discharged from the first spray nozzle at a position of 5 mm from a point where the extension line intersects a plane including a surface of the steel sheet toward the first spray nozzle when seen along the extension line of the center axis line of the first spray nozzle is 130 m/s or more and 520 m/s or less.

4. The device for producing a coated steel sheet according to claim 2 , wherein the inlet of the duct is provided with an extension member which receives the excessive coating directed to an outside of the inlet.

5. The device for producing a coated steel sheet according to claim 2 , wherein the first spray nozzle is disposed so that the discharge direction of the gas is along with the sheet threading direction when seen in the plan view.

6. The device for producing a coated steel sheet according to claim 1 , wherein the blowing-off unit is adjusted so that a discharge flow rate of the gas discharged from the first spray nozzle is 12 m 3 /h or more and 20 m 3 /h or less, a discharge flow velocity of the gas discharged from the first spray nozzle at a position of 5 mm from a tip end of the first spray nozzle in a discharge direction when seen along an extension line of a center axis line of the first spray nozzle is 420 m/s or more and 520 m/s or less, and a discharge flow velocity of the gas discharged from the first spray nozzle at a position of 5 mm from a point where the extension line intersects a plane including a surface of the steel sheet toward the first spray nozzle when seen along the extension line of the center axis line of the first spray nozzle is 130 m/s or more and 520 m/s or less.

7. The device for producing a coated steel sheet according to claim 6 , wherein the first spray nozzle is disposed so that the discharge direction of the gas is along with the sheet threading direction when seen in the plan view.

8. The device for producing a coated steel sheet according to claim 6 , wherein the inlet of the duct is provided with an extension member which receives the excessive coating directed to an outside of the inlet.

9. The device for producing a coated steel sheet according to claim 1 , wherein the inlet of the duct is provided with an extension member which receives the excessive coating directed to an outside of the inlet.

10. The device for producing a coated steel sheet according to claim 1 , wherein the first spray nozzle is disposed so that the discharge direction of the gas is along with the sheet threading direction when seen in the plan view.

11. The device for producing a coated steel sheet according to claim 1 , wherein the first spray nozzle is disposed so as to further satisfy the following Expression 4,
0.1≦sin α·cos β≦0.9  (Expression 4).

12. The device for producing a coated steel sheet according to claim 1 , wherein a shape of a discharge port of the first spray nozzle in a facing view is any of a rectangle, a circle, an ellipse, and a flat shape.

13. The device for producing a coated steel sheet according to claim 1 , further comprising:
a coating unit which forms a coating curtain by dropping a coating in a vertical direction onto the surface of the steel sheet,
wherein the coating unit includes a pair of curtain guides which imparts a constant thickness and a constant width to the coating curtain.

14. The device for producing a coated steel sheet according to claim 1 , wherein an extension of the center axis of the first spray nozzle contacts the first side edge of the steel sheet.

15. The device for producing a coated steel sheet according to claim 1 , wherein the opening area of the inlet of the duct is 1.9×10 5 mm 2 to 6.4×10 5 mm 2 , the opening area of the outlet of the duct is 1.3×10 5 mm 2 to 4.5×10 5 mm 2 , and the opening area of the opening of the coating container is 3.9×10 5 mm 2 to 1.4×10 6 mm 2 .

16. The device for producing a coated steel sheet according to claim 1 , wherein the blowing-off unit removes the excessive coating that accumulates along the first side edge and a second side edge of the steel sheet that threads along one direction, and
wherein the blowing-off unit further com

Assignees

• SOYA Katsuhide
• Nagatomi Masayoshi
• Shibao Fumio
• Furukawa Hiroyasu
• Nippon Steel & Sumitomo Metal Corp

Inventors

• SOYA Katsuhide
• Nagatomi Masayoshi
• Shibao Fumio
• Furukawa Hiroyasu

Classifications

• B05D1/305

  Curtain coating · CPC title

• B05D2202/15

  Stainless steel · CPC title

• B05C5/005

  Curtain coaters (B05C5/008 takes precedence) · CPC title

• B05C11/1039

  Recovery of excess liquid or other fluent material; Controlling means therefor · CPC title

• B05C11/06 Primary

  with a blast of gas or vapour · CPC title