Method and device for cooling and stabilizing strip in a continuous line

Abstract

The invention concerns a method for cooling metal strips using cooling chambers by blowing a gas, in a continuous heat treatment line, wherein: the chambers (4,4a...4', 4'a...) have a unitary dimension (h) in the moving direction (X) of the strip less than two meters and are split along the direction perpendicular to the moving direction (X) of the strip into a plurality of unitary blowing sectors; each unitary blowing sector is equipped with at least one blowing pressure sensor (7) and with at least one actuator (2) for adjusting the pressure of each of said unitary sectors; and a controlling and regulating system controls the actuators (2) such that the longitudinal theoretical distribution of pressure in the blowing sectors corresponding to a cooling curve of the target strip is adapted so as to take into account a modification of the position of the strip relative to the blowing sectors to avoid any contact thereof with the walls of the devices of the cooling zone without modifying the cooling curve.

Description

technical field [0001] [01] The invention relates to a continuous heat treatment line for metal strips, such as an annealing line or a metal-coated or organic-coated line. Background technique [0002] [02] In these types of heat treatment lines, according to the prior art, the cooling of the strip is carried out with a cooling box, and a gas such as a mixture of nitrogen and hydrogen is blown to an annealing line upstream of the zinc melting pot or to an electroplating line. In a closed cooling chamber, or after electroplating, air is blown, for example, into a cooling tower. [0003] [03] Instabilities of strips in cooling zones are known, for example in the form of a torsional deflection of the strip about its longitudinal axis up to a stable position, or a torsional vibration offset. [0004] [04] It is also common, depending on the type of rolling method, that the edges of the strip are longer than the middle. In this case, the belt is tensioned in the middle and its ...

AI Technical Summary

Problems solved by technology

It is common that the desire to eliminate the contact of the strip with the cooling box results in wrinkle defects, which originate from the thermal action caused by improper cooling, which comes from improper adjustment of the cooling distribution

Therefore, although there are lateral adjustments for the supply pressure of the cooling tank, operators often do not use these adjustments due to fear of degraded conditions, or do not correct them as good adjustments.

Consequently, the production capacity of each heat treatment line is limited by reducing the speed of the heat treatment line or by limiting the width of the strip to be produced to reduce thermal or contact defects on the surface of the strip, since the spare regulators are not utilized as well as possible. Tonnes

[0012] [12] Therefore, the methods and devices of the prior art cannot effectively control the cooling curve of the strip body and keep it in place in the cooling zone at the same time.

In addition, due to the imperfection of this background technology, if these methods and devices are not used correctly, it may lead to product defects

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