Device for generating a gas jet in processes for coating metal strips

Patent metadata

Field	Value
Publication number	US-9764349-B2
Application number	US-201214128431-A
Country	US
Kind code	B2
Filing date	Jun 21, 2012
Priority date	Jun 21, 2011
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

The device has a gas flow levelling pipe ( 3 ), which defines a continuous curved development surface (Z), at comprising a collector ( 4 ) to which a nozzle ( 10 ) is fixed, a delivery manifold ( 1 ), in order to introduce pressurized gas into the pre-chamber ( 2 ) through the holes ( 12 ), a first holed partition ( 5 ) and a second holed partition ( 6 ) within the levelling pipe ( 3 ), arranged perpendicular to the curved development surface (Z) of the pipe ( 3 ).

First claim

The invention claimed is:

1. A device for generating a flat, laminar gas jet, in particular suitable for hot coating processes for metal strips, comprising:
a longitudinal delivery manifold having a peripheral wall, a cross section, and a longitudinal extension, said peripheral wall being provided with first holes,
a levelling pre-chamber communicating with said, longitudinal delivery manifold through said first holes,
a curved levelling pipe communicating at a first end thereof with said levelling pre-chamber,
a nozzle adapted to generate the flat laminar gas jet,
said levelling pipe communicating at a second end thereof with said nozzle, said second end being opposite to and having a smaller cross section than the first end, so as to be tapered and to create a gas flow path from said levelling pre-chamber to the nozzle, said gas flow path defining a curve corresponding to the curve of the levelling pipe,
at least two holed partitions arranged in said levelling pipe and perpendicular to said curved gas flow path, thereby defining at least two successive, adjacent portions of the levelling pipe which are connected to each other,

wherein the first holes are provided in a first area defining a first radial arc of the peripheral wall of the longitudinal delivery manifold, and extending continuously along the whole length of the peripheral wall of the longitudinal delivery manifold, and said levelling pre-chamber extends externally at least about said first area,
wherein a first portion of the curved levelling pipe extends externally about a second area of the peripheral wall of the longitudinal delivery manifold, wherein said second area extends continuously along the whole length of the peripheral wall of the longitudinal delivery manifold and defines a second radial arc of the peripheral wall, said second area being adjacent to the first area,
and wherein a second portion of the levelling pipe is arranged in a substantially tangential direction with respect to the longitudinal delivery manifold, downstream of said second area, whereby an interior surface of the curved levelling pipe contains no angular points, so as to optimize the transformation of the gas flow from turbulent flow at the first end to laminar flow at the second end of the curved levelling pipe.

2. A device according to claim 1 , wherein said levelling pre-chamber is externally wound about said first area, and wherein said first portion of the levelling pipe is externally wound about said second area.

3. A device according to claim 1 , wherein said second area is limited to a radial arc of said cross section in the range from 30° to 180.

4. A device according to claim 3 , wherein said second area is limited to a radial arc of said cross section equal to approximately 90.

5. A device according to claim 2 , wherein said second area is limited to a radial arc of said cross section in the range from 30° to 180°.

6. A device according to claim 5 , wherein said second area is limited to a radial arc of said cross section equal to approximately 90°.

7. A device according to claim 1 , wherein said levelling pre-chamber only surrounds said first area.

8. A device according to claim 7 , wherein said first area has an radial arc of approximately 90°.

9. A device according to claim 1 , wherein a first stretch of the curved gas flow path is substantially at least one portion of a lateral surface of a cylinder, whereas a second stretch of said curved medial development surface, adjacent to said first stretch, is substantially a flat surface.

10. A device according to claim 1 , wherein said at least two holed partitions comprise a first holed partition and a second holed partition arranged downstream of said first holed partition.

11. A device according to claim 10 , wherein said first holed partition is arranged at the joining point between the levelling pre-chamber and the first portion of the levelling pipe.

12. A device according to claim 10 , wherein the second holed partition is substantially arranged at the joining point between the first portion and the second portion of the levelling pipe.

13. A device according to claim 11 , wherein the second holed partition is substantially arranged at the joining point between the first portion and the second portion of the levelling pipe.

14. A device according to claim 10 , wherein the section of said levelling pipe in a stretch between the first holed partition and an outlet pipe decreases to about ¼ of an initial value.

15. A device according to claim 10 , wherein said first holed partition comprises second holes and said second holed partition comprises third holes and wherein the diameter of holes on the peripheral wall, on the first holed partition and on the second holed partition decreases along the gas flow path as the number of holes increases.

16. A device according to claim 15 , wherein the diameter of said second holes is half of the diameter of said first holes and the number of said second holes is double the number of said first holes.

17. A device according to claim 15 , wherein the diameter of said third holes is half of the diameter of said second holes and the number of said third holes is double the number of said second holes.

18. A device according to claim 16 , wherein the diameter of said third holes is half of the diameter of said second holes and the number of said third holes is double the number of said second holes.

Assignees

• Vecchiet Fabio
• Cona Alessandro
• Caporal Gianluca
• Danieli Off Mecc

Inventors

• Vecchiet Fabio
• Cona Alessandro
• Caporal Gianluca

Classifications

• B05C11/06 Primary

  with a blast of gas or vapour · CPC title

• C23C2/20 Primary

  Strips; Plates · CPC title

• C23C2/40

  Plates; Strips · CPC title