1.1 Product positioning and production scale

1) Product positioning: the product is positioned as a color coated substrate with large consumption in the market but still tense

2) Production scale: 100,000 t / A.

1.2 product program

1.2.1 product specification

Hot dip galvanized coil: strip thickness 0.25~0.8mm

strip width 600~1,250mm

1.2.2 product distribution

See table 2.2.2-1 for specific product distribution of CQ level.table 2.2.2-1

Average specification of CQ grade: 0.45mm x1,030mm

1.3 Product performance

The product level is CQ: 100 %, and DQ can be produced

The quality standard shall comply with GB2518-2002

1.4 Coating weight

Double side coating: 80 ～150g / m2 (double side)

Average coating: 120g / m² (double-sided)

1.5 Plating state

No zinc flower, small zinc flower

1.6 raw materials

Raw material status: Cold rolled hard coil

Source of raw materials: Purchase from domestic and foreign markets

Steel grade: 08Al、SPCC、SPCD

Strip thickness: 0.2～0.8mm

Strip width: 600～1,250mm

Coil inner diameter: Φ500mm、Φ610mm

Outer diameter of steel coil: Φ800mm～Φ1,600mm

Coil weight: Maximum 15t

Mechanical properties: tensile strength: Max 810N/mm2

Annual demand: 100,000t

1.7 main technical parameters of the unit

1.7.1 Unit speed

Entrance section: 25～140m/min

Process section: 25～100m/min

Exit section (coiling section): 25～140m/min

Threading speed: 25m/min

1.7.2 main process equipment parameters of the unit

Welding machine: full automatic "C" type narrow lap automatic welding machine

Cleaning section: alkali soaking and brushing tank: ～ 5m

Electrolytic cleaning tank: ～ 6.0m (2 sets)

Water brushing and spraying tank: ～5m

Effective storage capacity of inlet looper: ～210m

Effective storage capacity of outlet looper: ～150m

Annealing furnace capacity: CQ: 21.2t/h

Zinc pot: Power frequency induction heating ceramic zinc pot

Capability: 140t

Power: 2 × 240kw

Zinc melting rate: Maximum 1.5t/h

Plating roller: Immersion roller: Φ650 × 1,500mm

Double stabilizer roll:  Φ200 × 1,500mm × 2 pcs

Tension leveler: elongation control 0.5 ～2.0 %

Total length of unit: About 180m

1.8 production process flow

Winding → uncoiling → shearing → welding → chemical degreasing → electrolytic degreasing → hot water spraying → squeezing and drying → inlet looper→ heating → soaking → cooling → hot dip galvanizing → small zinc flower device → air cooling after plating → water quenching and cooling after plating → drying → finishing (reserved) → tension straightening → passivation → drying → outlet looper→ electrostatic oiling →surface inspection → shearing → coiling.

1.9 characteristics of process equipment

1） The most advanced and widely used American steel union process in the world is adopted.

2） The advanced formula is used to produce non zinc flower products, the small zinc flower device is used to produce small zinc flower products, and the finishing machine is reserved to produce finished zinc flower products.

3） The strip steel cleaning section is set, and the advanced and practical chemical degreasing and electrolytic degreasing technology are adopted to enhance the degreasing effect and remove the oil stain and iron powder on the surface of the strip steel.

4） The reduction bright annealing furnace is set, and the full radiant tube is used for indirect heating. The heating is uniform, the control is simple, and the plate shape is good, which overcomes the disadvantage that it is difficult for most domestic units to produce thin strips.

5） Domestic advanced generator gas radiant tube burner is adopted, and the surface temperature difference of radiant tube is small. Uniform heating of strip steel and long service life of radiant tube. The whole furnace lining still adopts light structure. The furnace lining is ceramic fiber lining, which can effectively reduce the heat storage of the furnace body and reduce the control inertia of the furnace.

6） A number of advanced energy-saving measures have been adopted. If each radiant tube is equipped with a heat exchanger, the combustion supporting air can be preheated to about 300 ℃ by using waste gas; At the same time, the centralized heat exchanger is used to produce hot water, eliminating the waste heat boiler.

7） The cooling of the strip steel in the furnace adopts the protective gas circulating jet cooling device and frequency conversion regulation. The cooling speed of the strip steel is fast and uniform, and the temperature of the strip steel entering the zinc pot is accurately controlled.

8） The annealing furnace is lined with light fiber block, which has the advantages of fast furnace building, small thermal inertia and low furnace skin temperature.

9） The furnace is equipped with thermal tensioning roller to realize the sectional adjustment of strip steel tension between annealing furnace and coating section.

10） The jet ceramic induction zinc pot has the advantages of fast heating, uniform temperature, long service life and less zinc slag.

11） Single nozzle advanced air knife is adopted, and the coating weight and quality are well controlled.

12） Using domestic mature and practical two bending and one straightening tension straightener can effectively improve the shape and surface quality of strip steel plate and improve the competitiveness of products.

13） The domestic advanced electrostatic oiler is used to thin oil the strip steel to meet the requirements of color coated substrate.

14） Imported equipment shall be selected for CPC and EPC to ensure stable production of the unit.

1.10 unit control level

The unit adopts a master PLC, the CPU selects Siemens S7414-2DP as the master station, and all DC all digital devices and remote terminals in inlet, process and outlet operation status are connected as slave stations to form a PROFIBUS-DP network, so as to share the data of the production line. Set the speed and tension on the touch screen. The industrial computer is connected with the CPU through the communication template and can display the operation of each equipment on the production line.

1.12 main technical and economic indexes of the unit

Table of technical and economic indicators