INSTALLATION FOR CONTINUOUS HOT DIP COATING OF STEEL STRIP AND METHOD FOR ITS IMPLEMENTATION

Claims

1. An installation for continuous hot dip coating of a steel strip (1), comprising bath (2) with liquid metal; nozzles for jet regulation of coating thickness, equipped with edges (3) and a device (4) for cleaning the edges, capable of moving along the edges of the nozzle; isolating chambers (5) designed to limit the atmosphere around the trajectory of movement of the steel strip above the said nozzles; a space (6) for cleaning edges provided between said nozzles and said insulating chambers; means for supplying non-oxidizing gas to the insulating chambers (5); means for supplying non-oxidizing gas into the specified space (6) for cleaning the edges.

2. The installation according to item 1, containing means for setting the flow rate of gas supplied to the space for cleaning the edges.

3. The installation according to item 1 or 2, in which on each side of the steel strip (1) the gas supplied to the insulating chamber (5) and the gas supplied to the space (6) for cleaning the edges are supplied from the same source via an air duct (7).

4. The installation according to item 2 or 3, in which the means for setting the flow rate of gas supplied to the space for cleaning the edges comprise a plate (8), wherein said plate has perforated holes.

5. The installation according to item 4, in which said perforated plate (8) is an integral part of said air duct (7).

6. An installation according to any of paragraphs 1-5, equipped with anti-noise plates (9) in the side zones where the steel strip is not located, wherein said anti-noise plates are designed with the possibility of preventing the collision of frontal gas flows performing jet regulation.

7. An installation according to any one of paragraphs 1-6, in which the insulating chambers are equipped with flexible seals (10) that ensure lateral tightness of a limited area near the trajectory of the steel strip.

8. The installation according to item 7, wherein the flexible seals are capable of maintaining an operating temperature above 450°C.

9. An installation according to any one of paragraphs 1-8, in which the space (6) for cleaning the edges is equipped with sealing means that ensure the tightness of said space on the sides (11).

10. A method for continuous hot dip coating of a steel strip (1) in a continuous hot dip coating installation according to any one of paragraphs 1-9, comprising the following steps: immersion of the strip in a bath (2) with liquid metal; jet regulation of the thickness of liquid metal on a steel strip using said jet regulation nozzles equipped with edges (3), wherein said edges are equipped with a device (4) for external edge cleaning, capable of moving along the edges (3) of the nozzle in said space (6) for edge cleaning; moving the said steel strip (1), covered with a liquid coating, into insulating chambers (5), moreover, both into the specified insulating chambers (5) and into the specified space (6) for cleaning the edges, a non-oxidizing gas is supplied accordingly.

11. The method according to claim 10, in which the flow rate of non-oxidizing gas supplied to the space (6) for cleaning the edges is regulated, and the following equation is satisfied , where C is the flow rate of non-oxidizing gas supplied to the insulating chamber (5); R – flow rate of non-oxidizing gas supplied to space (6) for cleaning edges.