General Introduction
This unit is a continuous annealing galvanizing unit for cold rolled strip. It has the functions of electrolytic degreasing, annealing reduction, galvanizing, tension leveling, passivation, oiling (reserved) and so on.
This unit combines the specialties of the two processes of US Steel and Senjimir. The cold-rolled strip is cleaned by the electrolytic cleaning section and dried, then enters the annealing furnace for annealing and reduction, and then enters the zinc pot for heat in a sealed state. The aluminum-zinc is immersed, the thickness of the coating is controlled by an air knife, and the galvanized steel strip is obtained by a post-plating cooling process. Through the tension leveler to improve the surface quality of the coating and the mechanical properties and flatness of the strip, post-treatment to achieve passivation and reserve electrostatic oiling treatment, and finally get the finished galvanized steel coil.
All the equipment of this continuous hot-dip aluminium-zinc production line is designed and checked by modern technology, which matches each other perfectly. It can ensure the continuous and stable operation of the galvanizing line and obtain good varieties of galvanized steel coils.
Features of this Galvanizing Unit
1. The annealing furnace adopts two integrated processes: UEC (United Engineering Center) and Sendzimir. This production process integrates the expertise of the improved Sendzimir method and the UEC (United Engineering Center ) Process. The utility model can not only exert the characteristics of high heating efficiency of the improved Sendzimir method, but also realize the effect that the thin strip of the UEC method is not easy to break when it is produced, and the patented technology for energy saving and emission reduction has remarkable energy saving effect.
2. Annealing furnace - The annealing furnace uses a natural gas heating scheme. The heating section uses regenerative non-oxidizing direct heating technology, which is energy-saving. The reduction section adopts energy-saving radiant tube technology for soaking, the strip steel and combustion products are not in contact, the furnace temperature is low, the strip steel is not easy to be oxidized and broken, the zinc layer has strong adhesion, the product quality is good, and the production and maintenance are convenient.
3. The waste heat of annealing furnace burning exhaust gas is fully utilized and applied to the whole line of hot air drying and heating. It has good synchronization in use, saves energy and reduces production and operation costs.
4. The protective gas circulation ejector cooling device is used for the cooling of strip steel in the furnace, all of which are adjusted by frequency conversion. The cooling speed of strip steel is fast and uniform, which can meet the accurate temperature requirement of galvanized strip steel entering the pot.
5. The nose of the furnace is swing type with baffle, so that the sinking roll can be lifted out during shutdown. The steel strip does not need to be immersed in zinc solution for a long time, so as to avoid strip breakage and reduce the recovery time.
6. The air knife adopts a new multi-function advanced structure and a high-power multi-stage centrifugal fan. The weight and quality of the coating are well controlled.
7. The ceramic aluminum-zinc pot is heated by spray-type ceramic induction heating, which has the advantages of fast heating, uniform temperature, long service life and less zinc slag.
8. The online zinc layer thickness gauge can be configured to display the thickness of the zinc layer in real time, providing timely basis for gas knife control and saving cost.
9. Using two bends and one straightening machine can effectively improve the shape and surface quality of strip and improve the competitiveness of products.
10. The pre-treatment uses a powerful electrolytic degreasing section. To prevent nozzle clogging, a filter is placed at the inlet of each circulation pump. In the water brush washing section, a three-stage overflow scheme is adopted to save water consumption. The dryer is placed after degreasing and the steel strip is thoroughly dried.
11. Vertical roll passivation is adopted, and chemical treatment liquid is applied on both sides of strip to improve the adhesion, corrosion resistance and coating durability of strip surface.
12. The horizontal looper adopts a three-roller mobile trolley, which shortens the length of the looper when the sleeve is full, and three correction devices are arranged at the fixed steering roller, so as to ensure that the looper does not deviate when the sleeve is full. A set of alignment is installed between the inlet loop and the cleaning section to allow the strip to smoothly enter the cleaning section.
13. The arm-less hydraulic synchronous EPC is adopted, so that the winding of the front guide plate is smooth and the steel band head is not blocked.
14. Siemens AC variable frequency high speed drive control system has good man-machine interface and simple equipment maintenance.
Technical Parameters
1. Parameters of Incoming material / Finished Product
| Incoming Material |
Finished Products |
Raw material status: Un-annealed cold rolled low carbon steel strip
Steel type: Q195, Q235, 08F, 08Al, SPCC, SPCD
Strip thickness: 0.4-2.5mm
Strip width: 800-1250mm
Coil weight: Max 25t
Steel coil inner diameter: Ø 508mm / Ø 610mm (user selected)
Steel coil outer diameter: Max Ø2000mm
Cold rolled strip execution standard: GB/T 708-2006
Mechanical properties: Yield strength: σs=max 710N/mm2 |
Strip thickness: 0.4-2.5mm
Width of strip: 600-1250 mm
Coil weight: Max 15T
Coil inner diameter: 508mm
External diameter of steel coil: maximum 1800mm
Implementation Standards: Reference to GB/T 14978-2008
Coating weight: 60~180 g/m2 (double-sided galvanizing)
Surface state of products: ordinary ordinary spangle, small spangle or flattered spangle.
Coating protection: Chromium passivation, chromium-free passivation, oil coating (reserved) |
2. Production Speed
| Inlet section: |
120m/min (Max); |
| Outlet section: |
120m/min (Max); |
| Process section: |
80m/min; |
| Thread speed: |
Inlet 30 m/min
Outlet 30 m/min |
| Drive direction of unit: |
Right drive (right side of strip steel running direction) |
3. Analysis of working time
| Unit System |
Calendar time |
Planned stopping time |
The scheduled working hours |
Unscheduled down time |
Rated annual working hours |
Overhaul and
medium repair |
Regularly repair |
Subtotal |
| Four teams and three shifts running continuously |
8760 |
350 |
440 |
790 |
7970 |
970 |
7000 |
Audited Supplier 
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