Description:

1450 CONTINUOUS GALVANIZING LINE OF NATURAL GAS YEAR 2012

Used secondhand 1450 Continuous Galvanizing line of natural gas type. This line was established in 2012, and revamped in 2017.
Technical parameter and production program

1.1Overview

This unit is used to produce high quality hot-dip galvanized steel sheets with functions of annealing reduction, galvanizing, finishing, tensioning, passivation and oiling. According to the unit function and the strip processing sequence, the unit can be divided into an inlet section, a process section and an outlet section. The inlet section mainly includes unwinding, shearing, welding and degreasing processes, and continuously supplies strips for the process section; the process section mainly includes annealing and reduction sections, galvanizing, finishing, tensioning, passivation (or oiling) sections, etc. The process of strip steel; the exit section completes the inspection, splitting and coiling of the strip. The unit process is as follows: Roll up → unwind → cut head → weld → inlet loop → degreasing (alkali spray + alkali brush + electrolytic cleaning + alkali brushing + water cleaning + fresh water spray) → hot air drying → annealing reduction → protective gas cooling + galvanizing → Air cooling → Water quenching cooling → Hot air drying → Finishing → Pulling correction → Passivation → Hot air drying → Export looper → Inspection table → Slitting → Reeling → Unwinding → Packaging.

Main features of the unit:

1. Adopting the production process of U.S. Steel.

2. The horizontal looper adopts a four-roller mobile trolley, which shortens the length of the full looper and is set at the fixed steering roller to ensure that the looper does not deflect when it is full.

3. The combination of advanced and practical chemical degreasing and powerful electrolytic degreasing technology enhances the degreasing effect and removes oil stains and iron powder on the surface of the strip.

4. Set the reduction method bright horizontal annealing furnace, adopt electric heating scheme, indirect heating of the whole radiant tube, uniform heating, simple control and good layout.

5. The annealing furnace is made of light fiber with good thermal insulation performance, and the furnace is fast and the thermal inertia is small.

6.The steel strip cooling in the furnace adopts the protective gas circulation jet cooling device. The frequency conversion is adopted, and the cooling speed of the strip steel is fast and uniform, which can meet the accurate temperature requirements of the galvanized strip steel.

7. The air knife adopts the DQ advanced air knife. The coating thickness is evenly controlled, and the coating weight is up to 40g/m2.

8. It adopts ceramic zinc pot, and the heating adopts jet-flow ceramic induction heating, which has the characteristics of fast heating, uniform temperature, long service life and less zinc slag.

9. Four-roll wet finishing can effectively improve the surface quality of the product, eliminate the yield platform and improve the cold punching performance of the product: set the quick change roller and reduce the roll change time.

10. Double-curved double-aligning straightening machine can effectively improve the plate shape and surface quality and improve product competitiveness

11. Set up the CPC and EPC systems to ensure stable production of the unit.

12.The electric drive control system adopts Siemens 6SE70 system, AC frequency conversion speed control, realizes closed-loop control of tension and speed: PLC is a powerful SIMATIC S7-400 device with good man-machine interface and simple equipment maintenance.
1.2Production capacity and product outline
Annual production capacity
The production capacity of the annealing reduction furnace is 0.35x1000mm, 160m/min, the maximum hourly output of the unit is 30t/h, the total working hours of the unit is 7200h/year, and the maximum annual production capacity of the unit is 200,000 tons/year.
1.2. 1.2.2 Raw material and product data
1.Raw material
Raw material status: cold rolled hard steel coil
Steel: Q195, Q235, SPCC, SPCD
Strip thickness: 0.2-0.8mm
Strip width: 800-1250mm
Steel coil inner diameter: 508mm/610mm
Steel coil outer diameter: 1100mm/2100mm
Coil weight: 25T
Mechanical properties: yield strength max710N/mm2 

2.Finished product

Strip thickness: 0.2-0.8mm
Strip width: 800-1250mm
Steel coil inner diameter: 508mm/610mm
Steel coil outer diameter: maximum 2000mm
Coil weight: maximum 20T
Coating weight: 30-120g/m2 (double-sided aluminum-zinc-silicon), 50-200g/m2 (double-sided galvanized)
Surface condition: ordinary zinc flower or smooth zinc flower
Plating protection: passivation, oiling (reserved)
Executive standard: GB/T2518-2004
1.3
Basic data of the units
1.3.1
Line speed
Speed of entry and exit: 0-180m/min Process speed: 0-160m/min
thread speed: 30m/min
1.3.2 Unit output: 200,000 ton/year
1.3.3 Main equipment type and parameter of unit
1 Welder: FNY-200C type narrow lap automatic welding machine
Thickness of welded strip: 0.20~0.8mm;
Width of welded strip: 800~1250mm;
Overlap width: 3~5mm;
Weld height: less than 20% of substrate.
The maximum welding time is 45s, and the maximum automatic welding cycle is 60s.
2 Looper: entry horizontal looper effective storage 360m, Effective storage capacity of vertical looper for export 300m.
3、110m Continuous reduction annealing furnace: horizontal, electric heating: maximum hourly output: 33t/h (CQ) furnace length is about 110m
4、Zinc pot: power frequency induction heating ceramic zinc pot, capacity 140t, power: 4x300Kw
5 Skin pass mill: four roll wet leveling, maximum rolling force 300t
6 tension leveler: Double bending and double leveling, elongation control 05-2.0%.
7、Transmission control: SIEMENS AC frequency conversion control system.
8、CPC, EPC Correction Device.
1.4
Utility and Auxiliary Facilities