Side spray method for cooling the steel strip after hot rolling

Patent metadata

Field	Value
Publication number	US-11724296-B2
Application number	US-201916970508-A
Country	US
Kind code	B2
Filing date	Mar 22, 2019
Priority date	Mar 30, 2018
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

A side spray method for cooling a steel strip after hot rolling includes providing side spray devices behind multiple cooling sections on two sides in a width direction of a run out roller table of the steel strip after hot rolling. The side spray devices are staggered along the two sides of the run out roller table of the steel strip, the side spray devices include at least two spray units, each spray unit includes a spray tube and nozzles on the spray tube, the spray tubes being in parallel and vertically arranged along a running direction of the steel strip, and being movable along the running direction of the steel strip, covering ranges of the nozzles on the side spray devices are partially overlapped with each other, and a total spray coverage covering of nozzles covers a width of the run out roller table of the steel strip.

First claim

The invention claimed is:

1. A side spray method for cooling a steel strip after hot rolling, the side spray method comprising:
a) providing side spray devices behind multiple cooling sections on two sides in a width direction of a run out roller table of the steel strip after hot rolling, wherein the side spray devices are staggered along the two sides of the run out roller table of the steel strip, the side spray devices include at least two spray units, each spray unit includes a spray tube and nozzles on the spray tube, the spray tubes being in parallel and vertically arranged along a running direction of the steel strip, and being movable along the running direction of the steel strip, covering ranges of the nozzles on the side spray devices are partially overlapped with each other, and a total spray coverage covering of nozzles covers a width of the run out roller table of the steel strip, side spray water collecting devices being provided on an other side of the run out roller table of the steel strip that is opposite to side spray devices, so that side spray water being collected by the water collecting devices; and
b) controlling the side spray devices in a mode of open-in-pairs, wherein the cooling sections and side spray devices are numbered in the running direction of the steel strip after hot rolling such that each of the cooling sections is numbered as an odd number or an even number in the running direction of the steel strip after hot rolling, when a valve at the cooling sections with the odd number is opened, two consecutive staggered side spray devices behind the cooling sections are opened at a same time, and when the valve at the cooling sections with the even number is opened, the side spray device behind the cooling sections has been already open, and no further side spray device needs to be open.

2. The side spray method for cooling the steel strip after hot rolling according to claim 1 , wherein, when each side spray device has N spray units and N≥2, N spray units have N spray tubes, each spray tube is provided with one nozzle, and the width of the roller table of the steel strip is represented by Wg, a projection of each nozzle along the width of the roller table is named as water spray coverage of nozzle Ws, formula Ws≥Wg/N is satisfied, and
wherein an angle between a spray direction of the nozzle and the running direction of the steel strip is named as direction angle α, and N nozzles on the side spray devices are designated as 1˜N along the running direction of the steel strip, the direction angle α from a first to Nth nozzles is set as from large to small, and the direction angle α of the 1st to (N−1)th nozzles is from 110° to 165°, and the direction angle α of the Nth nozzle is from 75° to 105°.

3. The side spray method for cooling the steel strip after hot rolling according to claim 1 , wherein the nozzles on the side spray devices are designated as 1˜N along the running direction of the steel strip, and given a sequence number n, that is, n=1˜N, and a direction angle of the Nth nozzle is named as α n , length of water spray coverage of an Nth nozzle on a surface of the steel strip is L n satisfies L n =Ws/sin(180°−α n ), and installation spacing S n between an (N+1)th nozzle and the Nth nozzle satisfies S n =Ws/tan(180°−α n )−Ws/tan(180°−α n+1 ) when the direction angle of the Nth nozzle α N <90°, the installation spacing: S N−1 =Ws/tan(180°−α N−1 )+Ws/tan(α N ).

4. The side spray method for cooling the steel strip after hot rolling according to claim 1 , wherein a height h from the nozzle on the side spray device to a surface of the steel strip is set as 300˜700 mm, and the nozzles on the side spray device are designated in the running direction of the steel strip by 1˜N, and the height of the first to the Nth nozzles is set from low to high.

5. The side spray method for cooling the steel strip after hot rolling according to claim 1 , wherein the nozzles on the side spray device are designated by 1˜N in the running direction of the steel strip, and given serial number n, that is, n=1˜N, and
an incident angle R satisfies:
1st nozzle's incident angle β 1 =90°;
nth nozzle's incident angle
β n =arctan(h n /((n−1)×L n )), wherein n>1, h n is an nth nozzle height and L n is nth nozzle water spray coverage length,

nth nozzle's scattering angle θ n =arctan((n×L n )/h n )−(90°−β n ), wherein n>0,
h n is the nth nozzle height, L n is the water spray coverage length and β n is the incident angle.

6. The side spray method for cooling the steel strip after hot rolling according to claim 1 , wherein the side spray device has 2 to 5 spray units.

7. The side spray method for cooling the steel strip after hot rolling according to claim 1 , wherein the coverage of the nozzles on each side spray device has a certain overlap.

8. The side spray method for cooling the steel strip after hot rolling according to claim 1 , wherein the spray tube on a spray member is of a lifting design, so that the nozzle on the spray tube can be lifted up and down.

9. The side spray method for cooling the steel strip after hot rolling according to claim 1 , wherein the side spray water collecting device is a box body having an opening on one side that is corresponding to the side spray device, and at least two anti-collision arc plates are provided vertically on an opening side of the box body at intervals along a longitudinal direction, and a bottom plate of the box body is tilted, and provided with drainage hole.

10. The side spray method for cooling the steel strip after hot rolling according to claim 9 , wherein an opening side of the side spray water collecting device box body is provided with vertical anti-collision arc plates at both sides, respectively.

11. The side spray method for cooling the steel strip after hot rolling according to claim 1 , wherein the nozzle on a spray member is rotatable, and can rotate up, down, left and right.

12. The side spray method for cooling the steel strip after hot rolling according to claim 1 , wherein the side spray device includes:
water collecting pipe, connecting with water source through pipeline; and
at least two spray units with nozzles, where the spray tubes on the spray units are vertically arranged along a longitudinal direction of the water collecting pipe, and are movably connected to a fixed bracket through connecting piece, respectively, and are connected to the water collecting pipe through a hose, the spray tubes are adjustable for spacing, height and angle.

13. The side spray method for cooling the steel strip after hot rolling according to claim 12 , wherein the spray tubes on the side spray device are supplied with water through a water collecting pipe or a separate water inlet, and a water pressure and a flow rate are controlled independently.

14. The side spray method for cooling the steel strip after hot rolling according to claim 12 , wherein the water pressure of the water collecting pipe of the side spray device is 1.0 MPa to 2.0 MPa, and the flow rate is 10 m 3 /h to 20 m 3 /h.

15. The side spray method for cooling the steel strip after hot rolling according to claim 12 , wherein the spray unit is provided with an adjustable ball joint for adjusting a nozzle incident angle, including a nozzle forward inclination angle, and
wherein the nozzle is connected to the ball joint.

16. The side spray method for cooling the steel strip after hot rolling according to any claim 1 , wherein the nozzle is a fan nozzle or a tongue nozzle.

Assignees

• Baoshan Iron & Steel

Inventors

• Wu Jianfeng
• Wang Xiaobo
• Hu Zhaohui
• Zhang Yong
• Liu Wendong
• Zhang Qingfeng
• Liu Ye
• Xu Guohua

Classifications

• B21B45/0218 Primary

  for strips, sheets, or plates (B21B45/023, B21B45/0233 take precedence) · CPC title

• B21B45/0233 Primary

  Spray nozzles, Nozzle headers; Spray systems · CPC title

• C21D1/667

  for spray quenching · CPC title

• C21D9/573

  with cooling · CPC title

• B21B1/26

  by hot-rolling {, e.g. Steckel hot mill} · CPC title