Steel product processing plant with scale separation and recovery system

Patent metadata

Field	Value
Publication number	US-12434284-B2
Application number	US-202218712611-A
Country	US
Kind code	B2
Filing date	Nov 22, 2022
Priority date	Nov 23, 2021
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

The invention relates to a steel product processing plant, in particular including a rolling line and preferably upstream thereof a continuous casting line including at least one steel product direct cooling or cleaning system, or another system suitable to spray water on the product being processed; and a system for the separation of mixtures, in particular of a muddy nature, including water and scale deriving from said systems, which is provided with at least two pits (F 1 , F 2 ) for collecting the mixtures, wherein at least a first pit (F 1 ), advantageously provided with a dredging system for continuously removing the scale, is fed by water with coarse scale and at least a second pit (F 2 ) with water with fine scale and wherein said pits each have a maximum overall depth <10 m, preferably even less.

First claim

The invention claimed is:

1. A steel product processing plant, comprising at least one rolling mill provided with a plurality of stands arranged in series and suitable to progressively reduce the thickness of the product to be rolled in the advancement direction, and optionally a descaling machine and a continuous casting line arranged upstream of said rolling mill and of said descaling machine, wherein said plant is further provided with:
(a) at least one steel product direct cooling or cleaning system, or other system suitable to spray water on the product being processed;
(b) at least one system for separating mixtures, in particular mixtures of a muddy nature, comprising water and scale, deriving from said at least one steel product direct cooling or cleaning system, or from said other system suitable to spray water on the product being processed comprising:
(b-1) at least a first collection pit (F 1 ) of the mixtures;
(b-2) at least a second collection pit (F 2 ) of the mixtures;

wherein said pits (F 1 , F 2 ) each have an overall depth <10 m, preferably <8 m, still more preferably <6.50 m; and
wherein said at least a first collection pit (F 1 ) is fed with mixtures deriving from the casting or from said descaling machine and/or from one or more of the initial stands of the rolling mill and wherein said at least a second collection pit (F 2 ) is fed by one or more groups formed by the remaining stands of the rolling mill,
wherein said first collection pit (F 1 ) comprises:
(c) a dredging device, in particular a scraping conveyor.

2. The plant according to claim 1 , wherein each pit (F 1 , F 2 ) comprises:
(i) a channel or a channel system,
(ii) at least one collection tank of the mixtures into which said channel or said channel system opens.

3. The plant according to claim 1 , wherein said first pit (F 1 ) comprises inclined walls, in particular with an inclination between 45 and 75.

4. The plant according to claim 2 , wherein said channel or said channel system of said first pit (F 1 ) comprises a distribution bell which forms the inlet in said at least one collection tank of the mixtures of said first pit (F 1 ).

5. The plant according to claim 1 , wherein said at least one collection tank of the mixtures of said first pit is provided in an upper edge along a perimeter, with one or more channel(s) of clarified water overflow which feed(s) at least one clarified water collection tank included for such a purpose in said first pit.

6. The plant according to claim 5 , wherein said clarified water collection tank is arranged next to said at least one collection tank of the mixtures of said first pit.

7. The plant according to claim 1 , wherein it further comprises an emergency tank, preferably at a side of said at least one collection tank of the mixtures of said first pit, and wherein the inlet to said at least one collection tank of the mixtures of said first pit is made as a closed pipe with an emergency by-pass adapted to feed said emergency tank.

8. The plant according to claim 1 , wherein said pits (F 1 , F 2 ) are at least partially arranged below said at least one steel product direct cooling or cleaning system, or other system suitable to spray water on the product being processed.

9. A process for separating mixtures comprising water and scale deriving from a direct cooling and/or descaling of steel products comprising the following steps:
(I) producing metal scale in an oxidation process of a steel product in continuous casting and/or rolling processes;
(II) water jet descaling and/or direct cooling of the continuous casting and/or rolling product resulting in scale accumulation in the descaling and/or direct cooling water forming said mixtures comprising water and scale;
(III) conveying the mixtures with large size scale, in at least a first pit (F 1 ) with an overall depth of less than 10 m and preferably provided with a dredging device, such as a scraping conveyor, and removing the large size scale, in particular >500 μm, with said dredging device in a special container and diverting the clarified water, in particular by means of overflow elements present in said first pit (F 1 );
(IV) conveying the mixtures with scale of fine particle size, in particular ≤500 μm, into at least a second pit with a depth less than 10 m; and preferably removing the mixtures with pumps, without separation of the scale from the water, from the second pit.

10. A steel product processing plant, comprising at least one rolling mill provided with a plurality of stands arranged in series and suitable to progressively reduce the thickness of the product to be rolled in the advancement direction, and optionally a descaling machine and a continuous casting line arranged upstream of said rolling mill and of said descaling machine, wherein said plant is further provided with: (a) at least one steel product direct cooling or cleaning system, or other system suitable to spray water on the product being processed; (b) at least one system for separating mixtures, in particular mixtures of a muddy nature, comprising water and scale, deriving from said at least one steel product direct cooling or cleaning system, or from said other system suitable to spray water on the product being processed comprising: (b- 1 ) at least a first collection pit (F 1 ) of the mixtures; (b- 2 ) at least a second collection pit (F 2 ) of the mixtures; wherein said pits (F 1 , F 2 ) each have an overall depth <10 m, preferably <8 m, still more preferably <6.50 m; wherein said at least a first collection pit (F 1 ) is fed with mixtures deriving from the casting or from said descaling machine and/or from one or more of the initial stands of the rolling mill and wherein said at least a second collection pit (F 2 ) is fed by one or more groups formed by the remaining stands of the rolling mill; and wherein said first pit (F 1 ) comprises inclined walls, in particular with an inclination between 45 and 75 degrees.

Assignees

• Danieli Off Mecc

Inventors

• Nardella Antonio
• Zanetti Nino

Classifications

• B21B2263/02

  Profile, e.g. of plate, hot strip, sections · CPC title

• B21B45/0293

  Recovering coolants · CPC title

• B21B1/22

  for rolling {plates, strips,} bands or sheets of indefinite length (B21B1/42 takes precedence) · CPC title

• B21B1/463 Primary

  in a continuous process, i.e. the cast not being cut before rolling · CPC title

• B21B45/029 Primary

  Liquid recovering devices · CPC title