SU1222692A1 - Method of regulating temperature of workpieces in multiple-zone continuous induction furnace - Google Patents

Description

one

The invention relates to the regulation of heating and temperature control of billets in multi-zone induction installations consisting of a number of heating zones, in particular when heating billets in a continuous induction furnace before reducing or calibrating, before heat treatment and when heating solid long billets in forging press production .

The aim of the invention is to improve the accuracy of temperature control along the length of the blanks when heated in a multi-zone induction furnace.

The drawing shows an example of the implementation of the method.

The induction furnace consists of two heating zones 1 and 2 arranged in series along the path of the workpiece 3. Each heating zone 1 and 2 is powered by autonomous regulated sources 4 and 5 of the power supply, which have power control circuits 6 and 7 respectively. Temperature sensors 8 and 9 are installed, and temperature sensor 10 is also installed at the output of the last heating zone. The signal from the temperature sensors is received respectively at the adder 11-13, where the temperature is compared with their values — given by the setting devices 14-16. The regulator 17 is assigned to affect the power control circuit of the first zone in accordance with the signal from the adder 11 and the proportionality factor of the regulator is selected in accordance with the signal sum-Tojpa 12 with regard to the scaling device 18. The regulator 19 is designed to act on the power control circuit 7 of the second zone in accordance with the signal, g from the adder 12, and the proportionality factor of the controller is selected in accordance with the signal of the adder 13, taking into account the scaling mouth

roystva 20, I -

In the absence of blanks in the zone of the sensors 8 and 9 of the temperature at the entrance to the zones, the inductors are loaded with an average power Nj. When billet 3 appears in the sighting zone of temperature sensor 8, a signal appears at the output of the latter, proportional to

22692

temperature, is compared with the value set by setpoint 14, and the temperature deviation signal from the setpoint is received from adder 1 (P to regulator 17, which has a calculated coefficient of proportionality Ku, then the power of source 4,

to If the signal at the output of the first zone differs from the set one, then from the output of the adder 12 through the scaling device 18 a signal is sent to correct the proportionality factor of the regulator 17, at the same time from the cooler 12, through the regulator 19 and the power control circuit 7 powering the second zone 2 na30 heating. Then everything repeats as described.

The mobility of each heating zone is defined as follows;

25 N., + (K ,, - + K ,;) (T, „d .., -T ,,,,, ..,)

    ebu-j

thirty

35

40

45

$ 0

S5

where is NT

 hell;.,

yyh.,

-the power of each heating zone;

N is constant power,

which loads all zones in nominal mode;

K - coefficient taking into account the electrical and thermal parameters of the inductor and the amount and geometry of the metal entering the heating;

K, is the correction coefficient taking into account the temperature of the workpiece at the outlet of the corresponding heating zone;

K - is the electrical coefficient reflecting the dynamic properties of the control system, is selected from the conditions of the absence of self-oscillation when adjusting;

- calculated outlet temperature (i-1) of the heating zone;

- measured outlet temperature (i-I) of the heating zone;

1222692 4

T, g .. - design temperature The proposed method increases the exact output of the i-zone, the temperature of the temperature control along the wa; the length of the blanks. Economic vf-,. - The measured temperature can be obtained by

at the output of the i-zone by-5, reducing the consumption of metals.

Compiled by T.Naumova Editor A.Shandor Tehred G.Gerber Proofreader S.Cherni

Order 1670/25 Circulation 552 Subscription VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Filial PPP Patent, Uzhgorod, st. Project, 4

Claims (1)

METHOD FOR REGULATING BILLET TEMPERATURE IN A MULTI-ZONE PASS THROUGH INDUCTION FURNACE equipped with a temperature control system, including determining the temperature of the workpieces at the inlet and outlet of the first zone and generating a power control signal, such that, in order to increase the control accuracy along the length of the workpieces additionally determine the deviation of the temperature values at the input and output of each zone from their predetermined values and form a signal that controls the power of each zone in proportion to the deviation th temperature value at the inlet of this zone, a. the proportionality coefficient of the controller for each zone is changed depending on the magnitude and sign of the deviation of the temperature value at the outlet of this zone.