SU1653184A1 - Three-phase induction installation for heating metal bands by a transverse magnetic field - Google Patents

Abstract

This invention relates to electrothermal equipment and is intended for use in the continuous heat treatment process lines for flat rolled non-ferrous and ferrous metals. The aim of the invention is to increase the uniform heating of the belts and the efficiency in operation. The device contains a double-sided linear induction machine 1, braking 2 and pulling 3 rollers with drives 4 and 5. In the gap 6 there is a heat-insulating channel 7 in which the heated tape 8 passes. Drive 4 is powered from current source 9, and drive 5 is supplied with a source 10 power supply The windings of the halves of the induction machine are compensated and have opposite phase voltage, due to which the directions of propagation of the traveling magnetic fields are opposite, and the longitudinal forces completely compensate each other. Thus, the uniform heating of the belts and the efficiency of the installation are improved. 1 z.pa f-ly, 8 ill. g (L

Description

The invention relates to electrothermal equipment and can be used to create technological lines for continuous heat treatment of non-ferrous and ferrous flat-rolled products.

The purpose of the invention is to increase the uniformity of heating tapes and efficiency in the work

FIG. 1 shows schematically a three-phase current installation for heating sheet metal; figure 2 - cross section of one, for example the top, the core of the bilateral

a linear induction machine with a compensated coil-type winding laid in the grooves and an indication of the phase following; FIG. 3 is a schematic cross-sectional view of a double-sided linear inductor; figure 4 - schematic execution of one, for example the bottom, core induction machines with moving teeth; figure 5 - one of the possible electrical circuits of the compensated winding of the coil type; 6, 7, 8 - charts of instantaneous values

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traveling magnetic fields and contours of eddy currents in the tape for, for example, three possible shifts of the initial phase of the winding of the second half of the inductor.

The proposed device consists of (fig. U of a two-sided linear induction magazine 1, an inhibitory 2 and a driving roller 3 with drives A and 5, respectively, "In the gap 6 of the linear induction machine, there is a heat-insulating channel 7 in which there is a heated tape 8. Drive 4 is powered by a current source 9, and the drive 5 is provided with a 10o power source. The core 11) is made of electrical steel with grooves in which the winding 12 is located with the phase alternation shown in the figure. The winding is made with concentric coils with a relative pitch of 1/3 and phase zone 60 so that each coil covers one tooth. Such overlapping is compensated.

In Fig. 2, t is the pole division value. The width b of the cores of the two-sided induction machine (Fig. 3) is chosen to be 2/3 - 3/4 lp, where b p. y is the width of the working gap to accommodate the heated tape.

For an induction machine with movable teeth (Fig. 4), the rods 13, laminated from electrical steel, perform the role of teeth and are installed using detachable joints 14 on a common frame 15, also laminated from electrical steel.

The installation works as follows

When the unit is connected to the power source, the windings of the linear induction magines are excited in the gap 6 running magnetic fields, the direction of propagation of which corresponds to the direction of the arrows in Fig. 1 and 2o. . Interaction of a running magnetic field and the NDF currents in the tape are accompanied by the appearance of longitudinal forces whose directions coincide with the direction of propagation of traveling magnetic fields in each of the halves of the induction machine. Since the directions are spread

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the wounds of running magnetic fields are opposite, then the longitudinal forces almost completely compensate each other. The 8 ton drive of the driving rollers 3 is equipped, unlike the drive 7, with an automatic speed control system of the belt 6. The automatic speed control system has a speed sensor and an internal loop for regulating the ribbon temperature, which stabilizes the ribbon temperature when the supply voltage changes by changing the tape speed by the action on electric 8

The power circuits of the drives 7 and 8 can be connected in series and powered from a common current source, and the separate regulation of the tension and speed of the belt is carried out by acting on the drive circuitry of the drives.

The uniform heating of the tape across the width is ensured by selecting the optimum equivalent pole division. FIG. 6 - FIG. 8 shows diagrams of instantaneous eddy current circuits at different shifts of the initial winding phase of the second half of the inductor. The initial phase shift of the winding according to FIG. currents on the edges of the tape, which is beneficial for heating the edges of the tape. An increase in temperature at the center of the mite is more expedient than the phase shift, as shown in FIG. 7, since in this case the equivalent magnitude of the pole division becomes minimal. The phase shift shown in FIG. 8 is in an intermediate position. When changing the size of the heated tape by longitudinal and transverse movement of the movable teeth, the required width of the core and the magnitude of the pole division are selected.

Claims (2)

1. Three-phase induction installation for heating metal ribbons with a transverse magnetic field containing an inductor designed as a stator of a linear induction machine with at least two sections whose windings have opposite direction of the phase following to the outer ends of the sections, and installed on at least one side of the channel for the heated tape, and a system of drive-inhibiting rollers with drives at the input and pulling at the inductor output, in order to improve the uniform heating of the tape and profitability in the work, from the side of the channel opposite to the specified inductor, an indentical inductor of polarity matched with it is introduced, all parts of the inductors are of equal length, and the winding of each of them is compensated, 2. The installation is pop. 1, in order to expand the sizes of the heated ribbons, the teeth are made movable in the longitudinal and transverse directions. 6  / / ef A B C 2 X A 8 U 2 C Uxl one -1W 12 C / 2 U V XI SI UX A LUT R 2 zooooooooooooooooood. he. at br.z. FIG. F f t U. C C D L Ј O S C y y C & ch m FIG. five FIG. AT 75 FIG. four u C & UH / 1 | P | GPG01 St. VA Au 4.21ЈffЈЈ4.ЈiЈЈgOЈC42rЈIЈ2Ј4 but iGii A zЈiiЈiЈ..a.itlЈiЈЈiЈz.i GW VA Q 4C EZ