DE1565783C - Device for controlling the direct electrical heating of a moving, strand-like or band-like metallic item - Google Patents

Description

3 4

In the annealing system shown schematically, each of the following applies:

weils the current between the contact rollers 2 _. . _

Wire piece 1 through direct current passage s ~ T \ ^v ) - ^ r>

to be glowing. For this purpose the contact rollers 2 are over 2V, - = O ₁ J ₁ = {q · r · y · c · T) · ν = c · / (ν) = t / _H ,

an incandescent transformer 3 and connected in anti-parallel 5

thyristors 4, which act as alternating current controllers, where q is the wire cross-section, r is its specific wi-

nen, connected to an alternating voltage network. derstand per unit length, γ its weight, T die

The voltage U ₁ temperature and c is a constant on the contact rollers 2.

is detected with a voltage converter 10, so if the wire speed drops in a, then the

Bridge 11 can be rectified and reduced via an adjustable glow power, and vice versa,

Resistance 12 an input 17 of a Hall corresponding to the output signal of the controller 6

Multiplier 16 supplied. Likewise, the thyristors 4 are equipped with a control stage 5 by

the wire piece flowing current /, - controlled with a converter and thus the wire piece 1 supplied

15 detected, rectified in the bridge 13 and controlled via power. The recruitment of new operating

an adjustable resistor 14 to the input 18 15 values can easily be adjusted by adjusting the resistor

of the Hall multiplier 16 as a second input variable 7, 12 and 14 are made,

fed. The Hall multiplier and the thyristors correspond to the product of both quantities

corresponding output voltage U _n , which corresponds to the wire time constant in the order of magnitude of micro-

piecel supplied power corresponds to N ₁ , serves as seconds, the scheme shown works

Actual value for one with transistors and others 20 quickly and thus prevents deviations in the

non-contact elements built-up regulator 6. Wire quality. Furthermore, with the thyristors

The speed of the wire is determined by voltages of higher frequency than the mains frequency

with the contact roller 2 driven tachometer controls, which is particularly important for extremely short annealing stretches

machine 9 detected. The 8 in the same direction and high material speeds extra-

finished output voltage U _{T of} the tachometer machine 9 25 is quite advantageous.

is fed via an adjustable resistor 7 to the resistance heating in the direct current controller 6 and forms the reference variable N _s passage is not only due to the glow and godparents for power control. animals confined by wires and ribbons, but rather

This is possible because between the annealing power N _t and can also be used for rods and tubes.

Wire speed ν a linear relationship 30 The heating of the wire for application

consists. can be used in a coating.

1 sheet of drawings

Claims (1)

1 2 now extremely important that despite the relatively Claim · short annealing time at the end of the annealing section the good "exactly the glow required for recrystallization temperature has. Again, this is an exact one Device for controlling the direct electrical metering of the electrical energy to be supplied see warming of a moving strand or necessary. band-shaped metallic good between An example may make this clear; so amounts two contact points each a dosed power with an annealing length of 1 meter and a material can be fed, in which the reference variable of the line speed of 20 meters per second, the annealing control depends on the material speed only 5 · 10 ~ ² seconds. Is led to the recrystallization and the actual power value from the muI- tion is then only available for a time of approximately implication of electrical voltage and current 5 · 10 ~ ³ seconds,
is formed, with which the contact points over With the known arrangements is one for an actuator are acted upon, characterized in that this material speed is necessary, fast, which indicates that to control the fluctuations in the wire speed and the respective annealing material (1) during operation in an annealing power - especially with on and off annealing times of <C 5 · 10 ~ ² seconds to feed - the following regulation is not possible and a thyristor control element (4, 5) is used for the power, also no metering of the speed of the annealing material to be fed to the wire pieces between the contacts, even during fast start-up and shutdown effective 20 electrical energy. is, and that the circuits (6, 16) for formation also result in the known arrangements and supply of the control variable to the thyristor gen still particular difficulties when starting and Actuator made of contactless electronic construction processes at higher speeds. Both elements are built up. known arrangements is namely due to the 25 proper times of variable transformers or transductors and the control power required to control it to start up the system up to two for example at a speed of 20 meters a time of at least 30 seconds per second 30 is required because the actuators do not follow any faster be able. The same goes for going downhill. Want The invention relates to a device for controlling this time - and this what the direct electrical heating of a demand is made in modern machines in bizarre, strand-shaped or band-shaped metallic strengths - so you have to, if you are good , which between each two contact points a 35 _z . -B. the system starts up in 5 seconds so that dosed power can be supplied, in which case the management calculators calculate that every time over 100 meters of annealing material, the output control of the material speed can be used. speed is derived and the actual power value from which the object of the present invention consists Multiplication of electrical voltage and current is _now to remedy this situation and one is formed with which the contact points can be created via a device with which all disturbance variables are acted upon by the actuator. _ especially when starting up and coasting down - In the wire industry, continuous wire drawing with intermediate and final annealing is regulated without any significant deviation, so that the quality of the semi-finished product is as constant as possible and patented to an ever greater extent without incurring rejects. The wire is produced by utilizing 45. According to the invention, this object is achieved by its ohmic resistance in direct current, in that, in order to control the passage of the respective annealing material, it is heated. operationally in a glow time of <5 · 10 ~ ² seconds To ensure that certain limits of the power to be fed in, a thyristor part is heated are adhered to, it is known to have a link that is also used during rapid start-up and Provide a tachometer machine that has an effective speed of 5 ° departure from the speed of the annealing material of degree or volume is propor- tional, and that the circuits for formation and tational measuring voltage forms. This measurement voltage feeds the control variable to the thyristor actuator then provides the reference variable for the wire made of contactless electronic components electrical power. The actual value are built. the power supplied is given by the multiplier. 55 In this connection it should be noted that thyrition formed by glow current and glow voltage, and locking actuators and electronic multipliers are known per se from potentiometer computers or others, but only with annealing systems mechanical multipliers. As actuators through the inventive use of the Thyrifür the electrical power will be manual or disruptive with its low power level in Motor-operated variable transformers or transformers 60 connection with contactless controllers and electronics used (see for example German scher actual value determination it is possible to create a new Utility model 1 820913 or USA patent specification area to be technologically mastered, e.g. Glow-2 463 027). systems at a speed of 60 meters per These arrangements operate at relatively low seconds to operate, and also the approach and departure belt speeds still quite satisfactory. 65 ren at these speeds without losses the increase in the speed of the material dips increase. but the problem arises that at the same time the Heating available glow time reduced. It is explained in more detail as an example: