Pickling Line

Push-Pull Pickling Line

Instead of continuous pickling, the coil is uncoiled, moving forward and back under push and pull force of various rolls in push-pull pickling process for pickling coil by coil without tail of previous coil welded with head of next coil. This process, compared with the continuous pickling line is characterized by simple line equipment, easy operation and maintenance, good adaption to various strip sizes and varieties, needing less occupied area, lower investment and production cost, and short construction schedule, it is especially suitable for small and medium scale cold strip production.

New-type push-pull pickling line arranged with descaler and tension leveler can achieve leveling and sufficient descaling before pickling, elongation control and shape improvement.

In push-pull pickling process, shallow tank is used, allowing higher speed HCl turbulent flow and short pickling time and the motors are under VVVF drive control. Additionally, the line is also equipped with CPC and EPC system for centering and aligning the strip, high speed threading device for saving threading time and increasing line output, patented rotary side trimmer, scrap baller or chopper shear for achieving highly accurate trimming. The optimized acid fume cleaning system designed for the line has good environment protection effect, making the exhausted gas better than the National standard.

The push-pull pickling line can process strip with thickness up to 12mm, its actual production process speed ranges from 180 to 200 m/min, the ave. annual output approximately comes to 150,000~650,000 t/a and 700,000 t/a max., less than that of continuous pickling line because each coil needs to be threaded separately due to no welder.

For different required annual outputs and User’s requirements, following equipment can be arranged: coil preparation station, scrap baller or scrap chopping shear, electrostatic oiler or oiling roll, etc.

Main characteristics

  • Installation of vertical looper to ensure stable strip running, but no welder;
  • Adoption of shallow tank turbulent pickling and 5-stage counterflow cascade rinsing with conductivity of rinsing water controlled;
  • Application of automatic measurement and control, such as level, temperature and conductivity for acid liquid and rinsing water at process section;
  • Provision of good environment means, which can effectively protect the equipment and building from acid corrosion for getting longer service life;
  • Usage of CPC unit, making the strip entering the side trimmer in a center way after passing through the steering pinch roll which results in good trimming quality; and usage of EPC to cooperate the coiler for automatic straight sided coiling;
  • Utilization of VVVF drive system and basic automation control system to realize     closed loop control and operator friendly operation.

Technical data

Raw material: carbon steel、low alloy steel、high quality alloy steel

Strip thickness: 1.2~12.0mm

Strip width: 500~1650mm

Coil weight: max. 32t

Process speed: max. 180 m/min

Annual output: 100,000~700,000 t/a

Conventional process flow