I.Summary
The mill is intended for manufacturing of round pipe of Φ20mm-Φ76mm with thickness of 0.9mm–3.0mm from cold-rolled and hot-rolled coil strip by means of unclosed tubular blank with its subsequent welding into tube, edge heating by means of solid state high-frequency welder, longitudinal seam welding in rolls of tube welding machine, cooling, further sizing or shaping and on-stream cutting of endless tube in measured lengths.
Finished productwill be of round, square or rectangular pipe.
The manufacturing process provides for the uses of coiled strip precut in required width sizes in slitting machine.
II.The technical flow of the production line
{SteelTape}→→ Double-head un-coiler →→Strip-head Cutter and welder→→Spiral Accumulator →→Forming section (Flattening unit +Main driving unit +Forming unit +Guide unit +High frequency induction welding unit +squeeze roller) + De-burr frame →→Cooling unit →→ Sizing unit and straightener →→Flying saw under computer-control →→ Run-out table
III. Basic conditions:
- a) Steel Pipe Specification
- Round Pipe diameter: Φ20–Φ76mm
Pipe Thickness: 0.9-3.0mm
- Square Pipe: 15X15mm –60X60mm
Rectangle Pipe: 10X20mm –40X80mm
Pipe Thickness: 0.9– 3.0mm
3.Pipe Length: 6.0m±3mm
b)SteelTape Specification
1.Material: Low Carbon steel (δb≤500Mpa, δs≤275Mpa)
- SteelTape:
Inner diameter: Φ480-Φ550mm
Outer diameter: Φmax=1600mm
Strip steel width: 60mm-240mm
Strip steel thickness: 0.9– 3.0mm
The maximum weight: 3.0 tons
- c) Electricity
- Dynamic power: AC380V±10%, 3phases, 50Hz±1.0%
- Control Power: AC220V±10%, one phase, 50 Hz±1.0%
- d) Electric installed capacity:500KW
- e) Cooling water
- Reservoirfor High Frequencyequipment: 30 m³, one set
- Reservoirfor circulating cooling water: 30 m³, one set
- f) Compressed air
- Pressure: 0.4Mpa
- Flow: 1.0m3/h
- g) Production capacity
Annual output: 20,000 ton, according to the yearly working days、daily working hours and the products.
h)Line speed: 20-100m/min
- i) Feeding Direction: Right to left
- Equipment makeup and main parameters of single unit:
- Hydraulic Double-head un-coiler
1.1. Briefing: Rotary type to change coils easily, with a pneumatic brake
1.2. Parameters:
- Coil width: max.240mm
- Coil OD: max. Ø1600mm
- Coil ID: Ø 480- Ø 550mm
- Coil weight: max. 3.0 tons
1.3. Mandrel expansion by hydraulic
1.4. Mandrel position rotation shall be manual
1.5. Pneumatic brake
2.Shearing & butt welding machine
2.1 Shearing parameters machine:
- Cutting by Pneumatic
- Width: ≤240mm
- Thickness: ≤4.0mm
2.2 Butt welding machine by manual
- TIG welding machine TIG
- 3.Cage Loop
The reverse loop accumulator is installed between the shear& welder and the forming line, Its purpose is to give enough time for feeding the new coil from uncoiler to shear & welder to cut and join end of the new coil with tail end of previous coil.
|
Entry(Filling) speed |
180m/min |
|
Exit (Line) speed |
Max 100m/min, continuous operation |
|
Storage capacity |
400-800 meters |
- 4. Forming & sizing section
4.1 Forming mill
4.1.1 Mill entry flattener by up-horizontal roll and below-horizontal roll, one positive seven-roll flattener, one pair of feeding vertical roll.
4.1.2 Forming mill consists of:
- Driven stand: 7 sets (Horizontal)
- Driven stand shaft: Φ80mm
- Material of shaft: 42CrMo
- Side roll stand: 8 sets(Vertical)
- Side roll stand shaft: Φ45mm
- Material of shaft: 40Cr
- Gear box & universal joint: 7 sets
- Material of gear box: cast steel
- Material of bevel gear: 20CrMnTi
- Main motor : 75kW Model: Z4-225-11 1 set
- Main redactor : ZLY224 1 set
4.2 Sizing mill
4.2.1 Sizing mill consist of:
- Driven stand: 5 sets (Horizontal)
- Driven stand shaft: Φ80mm
- Material of shaft: 42CrMo
- Side roll stand: 5 sets(Vertical)
- Side roll stand shaft: Φ45mm
- Material of shaft: 40Cr
- Gear box & universal joint: 5 sets
- Material of gear box: cast steel
- Material of bevel gear: 20CrMnTi
- Turkshead: with 4rollers*2sets
- One speed testing roller for CNC flying saw
- Main motor : 75kW Model: Z4-225-11 1 set
- Main redactor : ZLY224 1 set
5.Welding section
5.1 Welding section consist of:
- Seam guide unit: 1 set
- Squeeze stand: 2 rollers(diameter轴径: Φ45mm)
- De-burr frame: 1 set (2 heads)
- Horizontal unit for seam ironing: 2rollers
5.2 Cooling section
- Cooling trough: 1 set
- Cooling trough length: 3.0 m
5.3 Solid state High frequency welder(GGP250KW)
GGp200KW
- Nominal power: 250kW
- Rated DC power: Pd=300kW
- Rated DC voltage: UdN=450V
- Rated DC current: IdN=670A
- The whole efficiency: η≥85%
- Output power: Pout＞250kW
- Designed frequency: f=300~350kHz
- MOSFET inverter: 60kW×5
- Tank circuit output mode: no welding transformer output, secondary resonance
- With water-water cooling system for welder
6. CNC flying friction saw
6.1 Flying cut-off, mechanical section consist of:
- Saw disk: OD600mm×ID80mm×4.0mm
- Saw waver: Pneumatic
- Pipe clamp: Pneumatic
- Saw carriage travel: Rack and pinion with gear lath
- Motor for travel: DC 15KW
- Motor for sawing: AC 22KW
- Length Tolerance: 0-6mm
- 7.Run-out table
7.1 Run-out system consists of:
- Roller conveyer 15 meter (including packing box)15m；
- Reversed pneumatically；
Pushed pneumatically；
8.ElectricControl System
8.1 Spiral Accumulator
- A.C. driver,
8.2 Double D.C. drive and control for forming and sizing mill.
- D.C. driver, ，
- Main D.C. drive panel control(instrument etc.)
- Mill operation panel (speed adjustment, control etc).
8.3 Flying cut-off control system
- Saw carriage drive by DC motor 15KW
- LCD operation pane
(length and batch setting ,control instrument etc).
9.Rollers
9.1 Forming and sizing Rollers material
- Material: Cr12
- Hardness: 60 HRC +/-2
9.2 Welding rollers material
- Material : H13
- Hardness: 50 HRC +/-3
