Aluminum tube induction heating continuous annealing production line

First, the machine structure

The continuous in-line annealing furnace is composed of a discharging mechanism, a clamping and fixing main machine, a heating intermediate frequency furnace, an intermediate frequency furnace for heat preservation, a quenching and drying mechanism, a tensioning mechanism, a receiving mechanism, an auxiliary system speed measuring device, and a computer control core system. In the continuous online annealing unit, the induction heating furnace is the core of the normal operation of the whole machine, and the computer automatic control system is the control core.

Process flow: the discharge basket is in place—the aluminum tube passes through the nesting roller to the front pinch mechanism through the loop detection mechanism—cleaning the outer wall—drying—horizontal straightening—vertical straightening—vertical pinching—induction heating—insulation— Quenching and cooling - blow drying - pinch tensioning mechanism - receiving

Control system structure and characteristics 
The aluminum tube induction heating continuous annealing production line is a fully automatic working mode. After the completion of the guiding work, the operator only needs to set the annealing line speed and the annealing temperature online, and all other operations are automatically realized by the computer. This control system has the following characteristics:

(1) The drive system of the receiving and discharging mechanism and the clamping mechanism adopts a series of vector controllers, and the driving system of the tensioning mechanism adopts a DC controller.

(2) The computer system uses Taiwan Advantech. The operating system xp can implement networked control.

(3) The human-machine interface adopts Samsung's 23 -inch LED screen touch screen, which is very convenient for operation and debugging personnel to carry out system monitoring.

(5) Application software In addition to the conventional logic control, the tube induction continuous annealing controller application software has the following functions:

1 P — V ( power-speed ) auto follow function. Intermediate frequency power supply according to pipe specifications and annealing process requirements

The output power automatically follows the change in the speed of the aluminum tube to ensure that the annealing temperature is stable. TL400 type tubes 20 at a speed 400m / min continuously adjustable.

2 Use the measured module to calculate the control voltage of the intermediate frequency power supply. The method is simple and reliable, and is not subject to temperature measurement devices.

Measure the impact of the operating state of the power system. The precise power control model guarantees the control accuracy of the annealing furnace.

3 aluminum tube micro tension control function. The aluminum tube is automatically built during the heating process, so that the aluminum tube is annealed.

Not stretched or shrunk in the state.

4 receiving and discharging speed compensation function. Use the loop detection and collection and discharge speed compensation calculation to ensure the receipt of the basket,

The discharging speed follows the linear velocity of the annealed aluminum tube, and the discharging is stable and the receiving is balanced.

Third, the main technical parameters of the equipment

Intermediate frequency heating furnace introduction:

  This heating device is designed for on-line annealing of aluminum tubes. It is designed for continuous heating and heating of workpieces in aluminum. In the system design, special parameters should be made for the parameters of power supply and inductor. The whole system is heated by two sets of 400KW/6KHZ power supply. The outside of the inductor is made of aluminum closed casing , which is filled with protective gas ( nitrogen ) to prevent heating and oxidation of the aluminum tube . This system has the following characteristics:

1.1 The intermediate frequency power supply is 400KW/6KHz . Due to the high power and high frequency, the power supply design has some special requirements. These will be detailed in the description of the power supply.

1.2 The intermediate frequency power supply and the sensor adopt the closed-loop cooling tower cooling mode , which makes the equipment small in size and easy to install.

1.3 Automatic continuous production, the production speed can be automatically adjusted according to different workpiece parameters.

1.4 The production line transmission raceway adopts frequency conversion speed regulation, and computer control can realize closed-loop control of temperature, speed and power.

2 , system equipment operation plan:

2.1 System power selection :

The total heating power is selected according to your requirements of 400m/min and is chosen to be 400KW .

2.2 Choice of the program:

According to the heating condition, the characteristics of the equipment used for heating in the fast operation, because the heating speed of the induction heating is too fast, there is no heat preservation process, thus affecting the refinement process of the aluminum tube grain structure, so the system adopts pulse type segmentation continuous The heating method is suitable for continuous heating. It is the most advanced heating method in foreign countries. This heating method can make the aluminum tube have a short-term heat preservation process in the non-furnace part. The annealing process of the aluminum tube ensures the refinement process of the grain structure, so that the internal crystal grains are fine and balanced, so that the aluminum tube can be tempered to meet the processing requirements of your company. At the same time, the heated aluminum tube in the heating furnace does not cause an excessive temperature difference in the axial direction, so that the micro crack caused by the thermal stress can be overcome in some procedures.

2.3   Equipment configuration and realization of the heating process:

The required power supply 400KW/6KHZ is used to supply two heating furnace bodies, and two heating furnace bodies are used to heat the aluminum tubes. After each furnace body is rapidly heated by the aluminum tubes, after a short period of heat preservation process, the process is There is no heating process. In order to prevent the aluminum tube from falling down when entering the next induction furnace, it is impossible to align, and the mechanical roller device is positioned in the middle; in order to prevent oxidation of the aluminum tube heating process, the two furnace bodies and the guiding portion are loaded into one In the sealed outer casing, inert gas is introduced into it; the length of each furnace body is 400MM , the distance between the mechanical roller device and the furnace body is 20mm on one side , and the total length of the furnace body is 800MM . Considering the space occupied by the outer casing The total length of the heating portion needs to be 1200 MM .                                                                            

The two furnace bodies and a set of mechanical roller device bases are fixed on the same furnace body base. The outer shell of the furnace body is made of hard aluminum alloy, which can simultaneously protect the gas sealing and magnetic shielding, so that the frame, the roller, etc. It is not heated by magnetic flux leakage; the shell of the furnace body is designed to be detachable, which provides convenience for the inspection of the furnace body and the replacement of the mechanical roller device.