Technical Requirements

Technical parameters for tube mill line

①Type of tube mill: Φ406tube mill

②Tube O.D.: Φ114~Φ406mm

③Wall thickness: 4.0~12.7mm

④Type of pipe: round pipe

2. Selection of seam annealer

①Configuration: 600kW seam annealer 1 unit (3 sets)

②Model: KGPS-600kW/1kHz 2 set

KGPS-600kW/2kHz 1 set

③Temperature setting scope: 600~950℃

④Temperature control precision: ±1%

⑤Heating seam width: >20mm

⑥Cooling method: air-water cooling

3. Annealing speed for typical specification

①Calculation conditions: A. Type of pipe: round pipe B. Power: 1800KW; C. Annealing temperature rise: 950℃.

②Annealing speed:

③Note:

• The speed in the above tables are calculated values on theory, and the actual operating speed will be affected by many factors such as mill modification, distance between inductor and pipe, seam position and so on.
• The above annealing speed is calculated based on the temperature of 950℃. For different material of steel pipe and annealing temperature, the annealing speed will be different.

Ⅱ. Technical Description for Seam Annealer

The application of seam annealing method promotes steel pipe quality level. Induction heater is the main part of steel pipe induction annealing equipment, which heat the pipe seam welded and quenched to critical temperature, this process can reduce welding stress and potential crack, and the produced close grains structure can guarantee producing tenacious steel pipe meeting all standard specifications. With the advantage of seam rapidly sectional heating, the oxydation and deformation of steel pipe can be made to be the minimum, and the precise diathermancy make the close grains in seam area conformity with its parent material.

1. Main features for seam annealer

• The inverter adopts 1500A/2000V rapid SCR to form parallel inverter circuit.
• The seam annealer power supply adopts the integration design of rectifying/inverter to achieve more compact structure and convenient maintenance.
• Adopt typical voltage and current intersection angle method timing phase-lock control to make the operation more reliable and high efficient; the adoption of tank circuit overvoltage/overcurrent protection circuit ensures the power supply protection be more precise.
• Adopt clutters wave start-up method with small impact and high successful rate.
• Tank circuit and plane inductor can be installed on adjustable mechanical positioning table, which can adjust the relative distance between inductor and pipe seam to be fit for the pipe online annealing of variable specifications.
• Adopt PLC and thermometric instrument of high precision to realize temperature closed loop to control the annealing temperature.