SU904205A2 - Device for regulating thermal mode of holding induction apparatus - Google Patents

Description

I

The invention relates to electrotermine and can be applied in methodical induction heaters.

According to the main author. St. No. 725277, a device for controlling thermal conditions of a methodical induction installation is known, comprising an inductor connected to the output of a regulated power source, the input of which is connected to the output of the adjustable unit, the first input of which is connected to the movement speed sensor and: second, the second to the product temperature sensor at the output from the inductor, and the third with a temperature sensor inside the inductor. A device may contain several autonomous zones, each of which is built according to this principle.

This device, due to the presence of feedback loops, by the temperature of the metal surface inside each zone of the heater provides

high stability of the temperature of the metal at the exit from the heater in transient modes of changing the speed of movement of the heated blanks of the joint venture. S

However, the device does not provide the required accuracy of maintaining the predetermined temperature of the metal in transient conditions for changing the size of (for example, diameter) heated billets.

The purpose of the invention is to improve the accuracy of maintaining a predetermined metal temperature at the exit from the heater in transient modes of changing the type dimensions of the heated billets: This goal is achieved by the device equipped with a product dimension sensor installed at the Inductor inlet and the output connected through a software unit to the input of an adjustable power source .

The drawing shows a functional diagram of the device with multiple zones.

The device contains a sensor 1 for moving metal through a heater 2, a sensor 3 for a metal temperature at the exit from each heater zone, a sensor 4 for metal temperature inside each heater zone, a sensor 5 for the heated products, an adjustable heater supply source 6, a functional control unit 7, a software device eight,

The device works as follows.

In the steady-state mode of constant movement of heated workpieces of the same type, signals from sensors 1, 3 and 4 act on the regulating blocks 7, which work out the deviation signal of the actual temperature at the exit of each heater zone from the set, set as a function of the speed of movement of the heated workpieces and their size . The control units 7, by acting on the power supply 6 of the heater zone 2, change the power supplied to each heater zone, so as to compensate for the indicated temperature deviation.

In a transient mode, the change in the dimension of the heated products, the sensors 5 act on the software devices 8 that control the adjustable power supply sources 6, so that a real time program for changing the heat power of the heater ensures a high accuracy of maintaining the set temperature at the outlet of each heater zone,.

. The time program for changing the heat power P (t) of the heater that minimizes the deviation of the metal temperature at the output is realized (FROM the heater from a predetermined value when changing the size of the preform, has a piecewise constant form, because the program device 8 implementing the time program for changing the heating power represents is a time relay unit that connects to the power source 6 control signals corresponding to the required power levels. In a transient change mode

The speed of movement of the metal through the heater of the device functions as in the main device.

In-quality sensors 5 dimensions of the heated blanks can be

used inductive sensor, it is possible to use transformer or capacitive sensors. The device improves the accuracy of maintaining the set temperature.

metal at the exit from the heater when changing the nomenclature of heated billets, which allows to eliminate the defect from overheating of billets when changing dimensions, reduces the consumption

electricity for heating, reduces the time to reach the steady state.

The economic effect from the introduction of the proposed device is 3.7 thousand rubles. on one installation per year.

Claims (1)

1. USSR author's certificate 725277 to. H 05 B 5/04, 1977.