News

10% increase in HDGL productivity thanks to the new X-JET air knives at MMK Metalurji, Turkey

Danieli received the Final Acceptance Certificate for the new air-knife system installed in the existing Hot Dip Galvanizing Line, in January 2016.

The MMK Metalurji Dortyol project in 2008 involved the supply of a complete Danieli hot and cold mill complex.

At that time the X-Jet technology was not yet available for industrial production (the first X-Jet installation occurred in mid-2009, in Italy), and so the MMK hot-dip galvanizing line was equipped with the Danieli Kohler S-Jet air knives.

Since 2008 the HDGL production mix has progressively moved to include a higher percentage of thin strips with very thin coatings (including Z70), and so the initial air knives had become a limit to higher processing speed, in effect a bottleneck to higher throughput.

The decision to install X-Jets followed technical discussions and a thorough analysis of the expected production benefits. Thanks to the modular design of Danieli Kohler’s air knives, the revamping included the re-use of many parts of the existing equipment, minimizing the capital investment. Danieli supplied new X-Jet air knives with lip cleaners, new blowers with special piping, modifications to the existing roll rigs and to the associated maintenance, and electrical and automation equipment.

The new X-Jets were installed during a scheduled, one-week maintenance shutdown.

The performance of the X-Jets in terms of coating weight versus line speed was immediately seen as a step change compared to the previous production parameters.

After the revamping the HDGL is able to daily produce Z100 at 180 meters per minute, and tests have shown the X-Jets to be capable of running Z80 with 40 g/m2/side at 180 mpm.

As a result of the X-Jet’s performance, HDGL productivity has increased by approximately 10%, with a payback time of less than six months for MMK.

By Danieli.