CN100406147C

CN100406147C - Transverse type induction heating device and transverse type induction heating system

Info

Publication number: CN100406147C
Application number: CNB2005100539408A
Authority: CN
Inventors: 江口俊信
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2004-09-08
Filing date: 2005-03-08
Publication date: 2008-07-30
Anticipated expiration: 2025-03-08
Also published as: JP4369332B2; JP2006075859A; KR100633520B1; KR20060043465A; CN1745921A

Abstract

The invention provides a transverse type induction heating apparatus which can prevent the excessive temperature rise of the surface of a plate to be rolled by almost uniformly heating the surface of the plate and the middle of the thickness of the plate at the central portion of the width of the plate to be rolled. In the transverse type induction heating apparatus for heating the plate 1 to be rolled by means of inductors 2, 3 to which electric power is supplied from an AC power source 4, the inductors 2, 3 are arranged on the center line of the width of the plate 1 to be rolled such that the width of the iron cores of the inductors 2, 3 in the direction of the width of the plate to be rolled is smaller than the width of the plate 1 to be rolled. The heating frequency of the AC power source 4 is set such that the depth [delta] of current penetration defined by the following expression (1): [delta]=[rho]/([mu]*f*[pi])}<1/2>, satisfies the following expression (2): 1.0<cosh(tw/[delta])+cos(tw/[delta])}/2<1.03, wherein [delta](m) is a depth of current penetration, [rho]([Omega]/m) is a specific resistance of the plate 1 to be rolled, [mu](H/m) is a permeability of the plate 1 to be rolled, f(Hz) is a heating frequency of the AC power source 4, [pi] is a ratio of the circumference of a circle to its diameter, and tw(m) is a thickness of the plate 1 to be rolled.

Description

Transverse type induction heating device and pressure-bearing type heating system

Technical field

The relevant pressure-bearing type heating system that is configured in the transverse type induction heating device on the iron and steel hot rolling line and adopts many transverse type induction heating devices to form of the present invention.

Background technology

In the past, have a kind of to the wide electromagnetic type induction heating apparatus that heats of view picture plate as to by the heater means again of the wide central part of plate of rolling sheets.(for example, opening flat 10-128428) number communique with reference to the spy.

In this electromagnetic type induction heating apparatus, in order to make since this part heat energy of high temperature that kelvin effect only forms on the surface fully to the diffusion inside of plate and make the temperature on surface be lower than the temperature of thickness of slab central authorities, will the regular hour, like this, the Temperature Distribution on the thickness of slab direction just can become suitable.

[patent documentation 1] spy opens flat 10-128424 communique (the 5th page, Fig. 1)

Summary of the invention

In the existing electromagnetic type induction heating apparatus, the heating frequency is high more, and induced-current just concentrates on by the surface of rolling sheets and flows, and the surface is produced excessively heat up.

In addition, the thickness of plate is thick more, and the excessive intensification of surperficial relative interior is bigger.

Therefore the problem that exists is, needs time enough to make the Temperature Distribution of thickness of slab direction suitable before finish rolling, and the place that is provided with of firing equipment also is restricted.

Again because of heating, so the problem that exists is when only wanting the wide middle body heating of plate, can waste electric power meaninglessly to the view picture plate is wide.

In addition, when the upper track of iron and steel hot rolling line was provided with many transverse type induction heating devices to next procedure, by behind the induction heating apparatus of last process, power supply can trip sometimes by the front end of rolling sheets.

The present invention proposes for addressing the above problem, and it is a kind of to being similar to the excessive transverse type induction heating device that heats up in the surface of heating, do not make plate equably by the plate of the wide central portion of plate of rolling sheets surface and thickness of slab central authorities that its purpose is to provide.

The pressure-bearing type heating system of the present invention's another purpose for providing a kind of upper track at the iron and steel hot rolling line that many transverse type induction heating devices are set to the next procedure, this pressure-bearing type heating system can prevented power source trip by the front end of rolling sheets after by the induction heating apparatus of last process.

The induction heating method of the application's transverse type induction heating device, configuration is by unshakable in one's determination and be wound on the inductor that the coil on the iron core is formed between iron and steel hot rolling line roughing mill and finishing mill, make it central across opposed in opposite directions by rolling sheets, utilize of described by rolling sheets being heated of the described inductor of ac power supply to the rollgang conveying

Make described inductor described wide less than described plate by rolling sheets by the width unshakable in one's determination on the rolling sheets plate width direction, and be configured on the wide center line of described plate by rolling sheets, if the electric current length of penetration be δ (m), described by the resistivity of rolling sheets be ρ (Ω-m), described be that the heating frequency of μ (H/m), described AC power is that f (Hz), pi are π, described when being tw (m) by the thickness of slab of rolling sheets by the magnetic conductivity of rolling sheets, described method is carried out following heating frequency setting step:

That is,, set the heating frequency of described AC power, make the electric current length of penetration δ of following formula (1) satisfy following formula (2) in order to be heated equably by the plate of the wide central portion of plate of rolling sheets surface and central being similar to of thickness of slab to described,

δ＝{ρ/(μ·f·π)} ^1/2……(1)

1.0＜{cosh(tw/δ)+cos(tw/δ)}/2＜1.03……(2)。

In addition; The application's pressure-bearing type heating system; Many transverse type induction heating devices are arranged on the last process of described iron and steel hot rolling line between next procedure; Described transverse type induction heating device disposes by iron core between iron and steel hot rolling line roughing mill and finishing mill and is wound on the inductor that the coil on the iron core forms; Make it central across in opposite directions opposed by rolling sheets; Utilize the described inductor of ac power supply to described the heating by rolling sheets of rollgang conveying

Make described inductor described wide less than described plate by rolling sheets by the width unshakable in one's determination on the rolling sheets plate width direction, and be configured on the wide center line of described plate by rolling sheets, if the electric current length of penetration be δ (m), described by the resistivity of rolling sheets be ρ (Ω-m), described be that the heating frequency of μ (H/m), described AC power is that f (Hz), pi are π, described when being tw (m) by the thickness of slab of rolling sheets by the magnetic conductivity of rolling sheets, carry out following heating frequency setting step:

δ＝{ρ/(μ·f·π)} ^1/2……(1)

1.0＜{cosh(tw/δ)+cos(tw/δ)}/2＜1.03……(2)

The inductor of many described transverse type induction heating devices is connected with AC power respectively one by one, the heating frequency that begins to establish described each AC power from the last process of iron and steel hot rolling line be F1, F2 ... Fn and K=1.05～1.20 o'clock, the heating frequency setting of each described AC power become to satisfy F1＞F2 * K＞...＞Fn * K ^N-1Relational expression.

Induction heating method according to the application's transverse type induction heating device, since make inductor by the width unshakable in one's determination on the rolling sheets plate width direction less than wide by the plate of rolling sheets, and be configured in by on the wide center line of the plate of rolling sheets, select the heating frequency to make the electric current length of penetration δ of aforesaid formula (1) satisfy aforesaid formula (2), thereby can prevent the excessive intensification on plate surface to being heated equably by the plate of the wide central portion of plate of rolling sheets surface and central being similar to of thickness of slab.

In addition, according to the application's pressure-bearing type heating system, can prevent by the front end of rolling sheets by power source trip behind the induction heating apparatus of last process.

Description of drawings

Fig. 1 for the formation of the transverse type induction heating device that relates to of expression example 1 and utilize this device eddy-current heating by rolling sheets plate width direction distance and the schematic diagram that on average concerns between the intensification value.

Fig. 2 for the thickness of slab (tw) of the transverse type induction heating device that relates to of expression example 1 to the ratio (tw/ δ) of length of penetration (δ) and plate surface heat density schematic diagram to relation between the ratio (plate surface/plate central authorities heat generation density) of thickness of slab central authorities heat generation density.

Fig. 3 is the enlarged drawing of the major part of Fig. 2.

Fig. 4 is the schematic diagram for the heat generation density distribution usefulness of thickness of slab direction of explanation pressure-bearing type and electromagnetic type induction heating apparatus.

Fig. 5 is the formation of the transverse type induction heating device that relates to of explanation example 2 and the schematic diagram of action.

Fig. 6 heats the schematic diagram that the front and rear panel temperature changes for transverse type induction heating device and the electromagnetic type induction heating apparatus that expression utilizes example 2 to relate to.

Fig. 7 is the schematic diagram of the winding wiring of the transverse type induction heating device that relates to of expression example 3.

Fig. 8 is in the transverse type induction heating device that relates to of expression example 3, by the spacing between the inductor iron core of the inductor iron core of rolling sheets and top and below and the schematic diagram of electrical loss.

Fig. 9 is the schematic diagram of the formation of the transverse type induction heating device that relates to of expression example 4.

Figure 10 is illustrated in the transverse type induction heating device that example 4 relates to, makes the schematic diagram that the thickness of slab direction heats up and distributes when being changed by the spacing between rolling sheets and inductor iron core.

Figure 11 be illustrated in the transverse type induction heating device that example 4 relates to, the ratio of (plate upper surface heat generation density)/(plate lower surface heat generation density) is for the schematic diagram of the ratio of (going up spacing)/(following spacing).

Figure 12 is formation that the pressure-bearing type heating system that example 5 relates to is described and the schematic diagram that moves usefulness.

Description of symbols

1,8,17 by

rolling sheets

2,3,19a,

20a inductor

2a, 3a, 9a,

10a

2b, 3b unshakable in one's determination, 9b, 9c, 10b, 10c coil 7a, 7b, 18a, 18b, 18c rollgang 8,17 by rolling sheets 19 the 1st induction heating apparatus 20 the 2nd induction heating apparatus

The specific embodiment

Example 1

Fig. 1 for the formation of the transverse type induction heating device of expression the invention process form 1 and utilize this transverse type induction heating device eddy-current heating by the schematic diagram that concerns between rolling sheets plate width direction distance and average intensification value.

Fig. 2 for thickness of slab (tw) in the transverse type induction heating device that is illustrated in example 1 that Fig. 1 (a) illustrates and relates to the ratio (tw/ δ) of length of penetration (δ) and plate surface heat density schematic diagram to relation between the ratio (plate surface/plate central authorities heat generation density) of thickness of slab central authorities heat generation density, Fig. 3 be with the schematic diagram after the major part amplification of Fig. 2.

Among Fig. 1 to Fig. 3, utilize the rollgang (not shown) between the roughing mill (not shown) of iron and steel hot rolling line and finishing mill (not shown), to be carried by rolling sheets 1.

Then, with the subtend configuration about in the of 2,3 of a pair of (one group) inductor, in the middle of making across by rolling sheets 1.

Inductor

2,3 is respectively by not constituted in wide 2a unshakable in one's determination, 3a of the plate of rolling sheets 1 and coil 2b, the 3b that is wound on 2a unshakable in one's determination, the 3a by the width unshakable in one's determination on the plate width direction of rolling sheets 1.

To each

coil

2b, 3b supply high frequency electric energy, the magnetic flux that utilizes 2a unshakable in one's determination, 3a generation is to being carried out eddy-current heating by rolling sheets 1 from AC power 4.

The width unshakable in one's determination of

inductor

2,3 is determined by mode of heating, now get smaller or equal to from gone the value behind the 300mm by the plate reductions of rolling sheets 1, have again,

inductor

2,3 is arranged on to be made on the wide center line of the plate of rolling sheets 1 by the wide end of the plate of rolling sheets 1 to the distance of 2a unshakable in one's determination, 3a leaves more than the 150mm at least.

Also have, so-called ' by the distance of the wide end of the plate of rolling sheets 1 to 2a unshakable in one's determination, 3a, be meant with the direction parallel by the plate face of rolling sheets 1 on, by the distance between the outer surface of the wide end of the plate of rolling sheets 1 and 2a unshakable in one's determination or 3a unshakable in one's determination (being A among Fig. 1 or the distance shown in the A ').

By like this, utilize experiment to confirm, almost can eliminate the excessive intensification of the wide end of plate, shown in Fig. 1 (b), the width regions unshakable in one's determination that comprises the wide central portion of plate is partly heated simultaneously.

Also have, what is called is configured in

inductor

2,3 by on the center line of rolling sheets 1, be meant

inductor

2,3 is configured on the wide central portion of plate, the part of 2a unshakable in one's determination, 3a is on the wide center line of plate, comprise that also the center configuration with

inductor

2,3 becomes consistent with the wide center line of plate.On the iron and steel hot rolling line, bigger by the wide mobility scale of the plate of rolling sheets 1, be 600～1900mm.

Therefore, the width unshakable in one's determination of 2a unshakable in one's determination, the 3a of

inductor

2,3 preferably is set in the scope of 300～700mm.

Following formula (1) is in the transverse type induction heating device of the invention process form 1, and the formula of the electric current length of penetration δ (m) that utilizes eddy-current heating is calculated in expression.

δ＝{ρ/(μ·f·π)} ^1/2……(1)

In the formula, ρ is that (Ω-m), μ is by the magnetic conductivity of rolling sheets 1 (H/m), and f is the heating frequency (Hz) of AC power 4, and π is a pi by the resistivity of rolling sheets 1.

The electric current length of penetration δ of Fig. 2 and Fig. 3 expression (1) and by the ratio of the thickness of slab tw of rolling sheets 1, and the heat generation density ratio of plate surface and thickness of slab central portion between relation.

Here, plate surface heat density can adopt by the thickness of slab tw of rolling sheets 1 and electric current length of penetration δ formula described as follows (3) the ratio of thickness of slab central authorities heat generation density and represent.

Plate surface heat density/thickness of slab central authorities heat generation density=

{cosh(tw/δ)+cos(tw/δ)}/2……(3)

The Temperature Distribution of the thickness of slab direction before the heating is owing to the influence of heat radiation, and the temperature on plate surface is lower than the temperature of thickness of slab central authorities.

Thereby, by the ratio (be plate surface heat density/thickness of slab central authorities heat generation density) of plate surface heat density to thickness of slab central authorities heat generation density is located at below 1.03, can on the thickness of slab direction, be similar to uniform heating, prevent the excessively intensification of plate surface.

Satisfied following formula (2) as long as select frequency to make by the relation between the thickness of slab tw of rolling sheets 1 and the electric current length of penetration δ in order to satisfy above-mentioned relation.

1.0＜{cosh(tw/δ)+cos(tw/δ)}/2＜1.03……(2)

On the iron and steel hot rolling line, the electricalresistivity by rolling sheets 1 that heating-up temperature is according to the rules handled is approximately about 120 μ Ω-cm, and relative permeability is 1.

Therefore, if the low suitable heating frequency of 161Hz when 287Hz, tw=40mm when 413Hz, tw=30mm when being selected than tw=25mm by the heating frequency of the thickness of slab tw of rolling sheets 1, then plate surface heat density is below 1.03 to the ratio of thickness of slab central authorities heat generation density, can on the thickness of slab direction, be similar to uniform heating, prevent the excessively intensification of plate surface.

Fig. 4 is the schematic diagram for the heat generation density distribution usefulness of thickness of slab direction of explanation transverse type induction heating device and electromagnetic type induction heating apparatus.

Among the figure, the characteristic of 5 expression electromagnetic type induction heating apparatuses, the characteristic of 6 expression transverse type induction heating devices.

The electromagnetic type induction heating apparatus is 0 at thickness of slab center heat generation density shown in characteristic 5 in theory, generates heat in the plate set of surfaces.

In contrast, transverse type induction heating device passes through suitably selected frequency, thereby can be shown in characteristic 6, and it is approximate even that heating is distributed.

In the example 1, be to be illustrated to a pair of (one group)

inductor

2,3 is configured in by the example on the wide center line of the plate of rolling sheets 1, but also can be along will being organized by the direction of advance of rolling sheets 1 on the position that (for example two groups)

inductor

2,3 is configured in same position on the plate width direction or left and right sidesing shifting more, by such can be with different in width corresponding by rolling sheets 1, heat according to the mode of heating of the best.

In addition, in the example 1, be that the example that magnetic pole to

inductor

2,3 is respectively one pole is illustrated, but as adopt above multipole in the two poles of the earth or the two poles of the earth, estimate also can obtain same effect.

Also having, in the example 1, be that the example that AC power 4 produces high-frequency electrical energy is illustrated, but the mains frequency of 50Hz or 60Hz also can satisfy the requirement of formula (2).

As mentioned above, the transverse type induction heating device of this example is with by 2a unshakable in one's determination, 3a, reach and be wound on above-mentioned 2a unshakable in one's determination respectively, coil 2b on the 3a, the inductor 2 that 3b forms, 3 are configured between the roughing mill of iron and steel hot rolling line and the finishing mill and make them opposed, in the middle of across by rolling sheets 1, and utilization is by the inductor 2 of AC power 4 power supplies, being heated of 3 pairs of rollgang conveyings by rolling sheets 1, in such transverse type induction heating device, make inductor 2,3 by the wide universal width unshakable in one's determination of the plate of rolling sheets 1 less than wide by the plate of rolling sheets 1, and be configured in by on the wide center line of the plate of rolling sheets 1, if the electric current length of penetration is δ (m), by the resistivity of rolling sheets 1 is ρ (Ω-m), by the magnetic conductivity of rolling sheets 1 is μ (H/m), the heating frequency of AC power 4 is f (Hz), pi is π, above-mentioned when being tw (m) by the thickness of slab of rolling sheets, set the heating frequency of AC power 4, make the electric current length of penetration δ of following formula (1) satisfy following formula (2).

δ＝{ρ/(μ·f·π)} ^1/2……(1)

1.0＜{cosh(tw/δ)+cos(tw/δ)}/2＜1.03……(2)

Its result, the transverse type induction heating device of the invention process form can be similar to equably and thickness of slab central authorities surperficial by the plate of the wide central portion of rolling sheets plate are heated, and can prevent the excessively intensification of plate surface.

Example 2

The formation of the transverse type induction heating device that Fig. 5 relates to for explanation the invention process form 2 and the schematic diagram of action.

Shown in Fig. 5 (a), between the roughing mill (not shown) of iron and steel hot rolling line and finishing mill (not shown), utilize rollgang 7a, 7b to carry by rolling sheets 8.

Then, will have respectively a pair of inductor 9, the 10 subtends configuration of two (a plurality of) magnetic poles, make in the middle of it across by rolling sheets 8.

Inductor

9,10 respectively by by the width unshakable in one's determination of the plate width direction of rolling sheets 8 less than being constituted by wide 9a unshakable in one's determination, 10a of the plate of rolling sheets 8 and

coil

9b, 9c, 10b, the 10c that is wound on each magnetic pole.

Each

coil

9b, 9c, 10b, 10c are supplied with high-frequency electrical energy from the AC power (not shown), utilize magnetic flux that the magnetic pole of each 9a unshakable in one's determination, 10a produces being carried out eddy-current heating by rolling sheets 8.

The same with example 1, the width unshakable in one's determination of

inductor

9,10 is configured in 9a unshakable in one's determination, 10a by on the wide center line of the plate of rolling sheets 8 for smaller or equal to from gone the value behind the 300mm by the plate reductions of rolling sheets 8.

In the above-mentioned formation, be 150Hz in frequency (promptly heating frequency), be that 40mm, transporting velocity are that 60mpm, average intensification amount are that 20 ℃ impose a condition is when heating by the thickness of rolling sheets 8 according to the AC power (not shown), shown in Fig. 5 (c), adding the approximate intensification of pining for equably in plate surface and thickness of slab central authorities.

Here, in induction heater, with solenoid according to the condition identical with pressure-bearing type when heat by rolling sheets, by rolling sheets by in the process of solenoid, thickness of slab central authorities heat up hardly, and the obviously intensification of plate surface.

With respect to average intensification value is 20 ℃ setting value, and excessively heating up in moment (hastily) in the plate surface is 52 ℃, about 2.6 times.

Distributed shown in Fig. 5 (b) by the heating of rolling sheets 8, begin expansion from position, according to circumstances till the rollgang 7a, the 7b that are configured in

inductor

9,10 front and back with

inductor

9,10 subtends.

Therefore, the electric current that flows on by rolling sheets 8 might produce spark at the contact point with rollgang 7a, 7b.

For preventing the generation of above-mentioned phenomenon, for example be coated in the surface of rollgang 7a, 7b with insulating materials such as ceramic coatings, prevent to be flowed into rollgang 7a, 7b by the electric current that flows on the rolling sheets 8.

The schematic diagram that Fig. 6 utilizes transverse type induction heating device and the plate temperature of electromagnetic type induction heating apparatus before and after heating to change for expression.

Use the electromagnetic type induction heating apparatus, on the plate surface and thickness of slab central authorities heat up to set 20 ℃ of humidity in order to reach, when transporting velocity is 60mpm, need more than 20 seconds, being converted into distance needs 20m.

In contrast, can reach with interior in the several seconds with transverse type induction heating device.

Example 3

The schematic diagram of the winding wiring of the transverse type induction heating device that Fig. 7 relates to for expression the invention process form 3.

Among Fig. 7, AC power 4 is identical with example 1, and is identical with example 2 by rolling sheets 8 and

inductor

9,10.

Among Fig. 7 (a),

coil

9b, 9c, 10b, the 10c of each

inductor

9,10 are connected in series, and connect AC power 4 and matching capacitor 11.

In addition, among Fig. 7 (b), be configured in by coil 9b, the 9c of the inductor of rolling sheets 8 tops (go up inductor) 9 and be connected in series, the coil 10b, the 10c that are configured in the inductor (following inductor) 10 of below are connected in series.

Then, be connected in parallel by coil 10b, the 10c of coil 9b, the 9c of rolling sheets 8 tops and below and AC power 4.

Shown in Fig. 7 (a), at coil 9b, the 9c of

inductor

9,10, when 10b, 10c all are connected in series, even balanced configuration is not about by rolling sheets 8 for

inductor

9,10, the electric current that flows through all

coils

9b, 9c, 10b, 10c is also all identical, and the electrical loss of each

inductor

9,10 equates.

On the other hand, shown in Fig. 7 (b), at the coil 10b of coil 9b, the 9c of inductor 9 and inductor 10, when 10c is connected in parallel, because near being diminished by the coil impedance of rolling sheets 8 one sides, flow through more electric current, so near being become big by the inductor electrical loss of rolling sheets 8 one sides.

Fig. 8 is for representing by the schematic diagram of spacing and electrical loss relation between the iron core of the inductor 10 of the iron core of the inductor 9 of rolling sheets 8 and top and below.

Among Fig. 8, (a)

expression inductor

9,10 unshakable in one's determination and equated, be the situation of 90mm up and down by the spacing between the rolling sheets 8, (b) inductor 9 unshakable in one's determination and be 50mm, inductor 10 unshakable in one's determination and be the situation of connection shown in Fig. 7 (a) of 130mm and

coil

9b, 9c, 10b, 10c down in the expression, (c)

expression inductor

9,10 and and situation that coil 9b, 9c and coil 10b, 10c as Fig. 7 (b) shown in be connected in parallel identical with (b) up and down by the spacing between the rolling sheets 8 by the spacing between the rolling sheets 8 by the spacing between the rolling sheets 8.

Fig. 8 is according to any result who is compared by the identical condition of average intensification amount of rolling sheets 8.

When equating at 9a unshakable in one's determination, the 10a of each

inductor

9,10 up and down with by the spacing between the rolling sheets 8, then as Fig. 8 (a) shown in, the electrical loss of each

iron core

9,10 is equal.

With last different be, shown in Fig. 7 (a), coil 9b, the 9c of top and the coil 10b of below, when 10c is connected in series, even 9,10 pairs of inductors are not had balanced configuration by rolling sheets 8, but because the electric current that flows through in all

coil

9b, 9c, 10b, 10c is identical, so the electrical loss of each

inductor

9,10 much at one.

In addition, shown in Fig. 7 (b), coil 9b, the 9c of top and the coil 10b of below, when 10c is connected in parallel, then shown in Fig. 8 (c), it is big that the loss of closely spaced inductor 9 one sides becomes, and big such as the situation loss that connects shown in Fig. 7 (a).

As mentioned above, as the coil 10b of coil 9b, the 9c of top and below, when 10c is connected in parallel, because of close more by the electric current that flows through among coil 9b, the 9c of rolling sheets 8 one sides, electrical loss near the inductor 9 of this side becomes big, it is not enough that the cooling capacity of coil seems, so might be limited in the electric current that coil midstream is crossed, and restriction is by the intensification value of rolling sheets 8

On the contrary, shown in Fig. 7 (a), the electrical loss that can make each

inductor

9,10 by all

coil

9b, 9c, 10b, 10c are connected in series much at one.

Example 4

The schematic diagram of the formation of the transverse type induction heating device that Fig. 9 relates to for expression the invention process form 4.

Among Fig. 9, identical with example 1 by rolling sheets 8,

inductor

2,3 and AC power 4.

Among Fig. 9, configuration can be along the chassis 12 that is moved by rolling sheets 1 plate width direction.Each

inductor

2,3 can be distinguished lifting separately by being configured on the chassis 12 every seeing by rolling sheets 1 subtend in the middle of the lifting means 13,14.

Coil 2a, the 3a of

inductor

2,3 connects AC power 4 by the matching

capacitor

15,16 that is configured on the chassis 12.Also have, matching

capacitor

15,16 also can be arranged with chassis in 12 minutes.

In the transverse type induction heating device of above-mentioned formation, be configured in by

inductor

2,3 liftings of rolling sheets about in the of 1 by utilizing lifting means 13,14 to make, thereby can optionally adjust each

inductor

2,3 and by the spacing between the rolling sheets 1.

Figure 10 is the schematic diagram that is illustrated in the transverse type induction heating device that example 4 relates to, makes by rolling sheets 1 and distribute in the intensification of thickness of slab direction when the spacing between 2a unshakable in one's determination, the 3a of the

inductor

2,3 of configuration changes up and down.

As spacing difference up and down, then, a kind of like this tendency is arranged all no

matter coil

2b, 3b up and down is connected in series or is connected in parallel, promptly closely spaced side plate face heats up big.

Figure 11 is illustrated in the transverse type induction heating device that example 4 relates to, and the ratio of (plate upper surface heat generation density)/(plate lower surface heat generation density) is for the schematic diagram of the ratio of (going up spacing)/(following spacing).

Among Figure 11, as spacing difference up and down, then closely spaced side plate surface is heated up big.

Like this since between the upper and lower apart from not simultaneously, just different by rolling sheets 1 in the intensification of thickness direction, so according to by the thickness of slab of rolling sheets 1, by adjust the position of each

inductor

2,3 with lifting means 13,14, make between the upper and lower apart from identical, thereby on the top and bottom of plate, produce same intensification.

Before

inductor

2,3, depended on the situations such as heat absorption of rollgang (not shown) during the operating mode of utilizing combustion gas to heat, supporting are by the heat absorption of the slideway (not shown) of rolling sheets 1 or the conveying way after releasing by rolling sheets 1 in the Temperature Distribution of thickness of slab direction in heating furnace from heating furnace, there is the tendency that is lower than the top by rolling sheets 1 below temperature in Temperature Distribution.

Thisly may be made the quality instability of plate, and influence machining property by the temperature difference of the top and bottom of rolling sheets 1.

But, according to above-mentioned formation, because can make each

inductor

2,3 lifting up and down with lifting means 12,13, adjust each

inductor

2,3 and by the spacing between the rolling sheets 1, by adjusting the spacing of below littler than the spacing of top, and just the temperature below the plate rises than high above the plate, so can make the top and bottom of plate form even temperature.

Example 5

Figure 12 is formation that the pressure-bearing type heating system that the invention process form 5 relates to is described and the schematic diagram that moves usefulness.

The pressure-bearing type heating system that this example 5 relates to is characterised in that, begins to next procedure from the last process of iron and steel hot rolling line, disposes many transverse type induction heating devices with formation of example 1.

Also have, last process one side that Figure 12 is illustrated in the iron and steel hot rolling line disposes the 1st induction heating apparatus 19, disposes the situation of the 2nd induction heating apparatus 20 in next procedure one side.

In addition, Figure 12 (a) expression is begun situation by between the inductor 19a of the 1st induction heating apparatus 19 time by the front end of rolling sheets 17 (wrench), and Figure 12 (b) expression is begun situation by between the inductor 19a of the 1st induction heating apparatus 19 time by the end of rolling sheets 17 (plate tail).

Among Figure 12, leaned on rollgang 18a～18c to be transported to the right-hand of figure from the left of figure by rolling sheets 17.

Along by the direction of advance of rolling sheets 17, begin to dispose the 1st induction heating apparatus 19 and the 2nd induction heating apparatus 20 from last process.

And induction heating apparatus 19,20 has AC power (not shown) separately respectively.If the frequency of the AC power (not shown) that is connected with the induction heating apparatus 19 of production line last process one side is F1, the frequency of establishing the AC power (not shown) that is connected with the induction heating apparatus 20 of production line next procedure one side is F2.

Establishing the frequency that begins the AC power (not shown) that is connected with n platform induction heating apparatus from last process one side again is Fn, in K=1.05～1.20 o'clock, the frequency setting of the AC power (not shown) of last process one side and the AC power (not shown) of next procedure one side becomes to satisfy following formula (4).

F1＞F2×K＞…＞Fn×K ^n-1……(4)

Under the no-load condition between inductor 19a, the 20a, impedance does not increase transverse type induction heating device about not being in by rolling sheets 17.

Thereby, when the frequency converter that moves in the resonant frequency that will follow the tracks of load uses as AC power, as shown in figure 12, when being arranged, load compares, and frequency reduces.

The front end that is begun to carry from last process by rolling sheets 17 is by when inductor 19a, the 20a, must be lower than the heating frequency of the induction heating apparatus 20 of next procedure one side as heating frequency setting with the induction heating apparatus 19 of last process one side, then the front end of plate by after induction heating apparatus 19 and the front end of plate by in the heating frequency of induction heating apparatus 20 of next procedure identifying in a flash.

Therefore, might magnetic interference take place 19,20 of adjacent induction heating apparatuses, and make heating-up temperature instability or power source trip.

But by the frequency of the AC power (not shown) of production line last process one side being established, thereby can prevent the power source trips that produced by induction heating apparatus 19 backs of the front end of rolling sheets 17 by last process one side than the frequency height of the AC power (not shown) of next procedure one side.

As mentioned above, the pressure-bearing type heating system of the invention process form is a kind ofly many examples 1 described transverse type induction heating device is arranged on the iron and steel hot rolling line begins to the pressure-bearing type heating system between the next procedure from last process, because the inductor of many transverse type induction heating devices is connected with AC power respectively one by one, the heating frequency that begins to establish above-mentioned each AC power from the last process of iron and steel hot rolling line is F1, F2, Fn, and in K=1.05～1.20 o'clock, the heating frequency setting of above-mentioned each AC power become can satisfy " F1＞F2 * K＞...＞Fn * K ^N-1", so the frequency of the AC power of iron and steel hot rolling line last process one side can be higher than the frequency of the AC power of next procedure one side, can prevent by the power source trip that produces behind the induction heating apparatus of rolling sheets front end by last process one side.

Industrial practicality

The present invention is applicable to can be to being similar to by the plate of the wide middle body of rolling sheets plate surface and thickness of slab central authorities Uniformly heating, the transverse type induction heating device and the pressure-bearing type eddy-current heating that do not allow the plate surface excessively heat up System.

Claims

1. the induction heating method of a transverse type induction heating device, configuration is by unshakable in one's determination and be wound on the inductor that the coil on the iron core is formed between iron and steel hot rolling line roughing mill and finishing mill, make it central across opposed in opposite directions by rolling sheets, utilize of described by rolling sheets being heated of the described inductor of ac power supply to the rollgang conveying, it is characterized in that

δ＝{ρ/(μ·f·π)} ^1/2……(1)

1.0＜{cosh(tw/δ)+cos(tw/δ)}/2＜1.03……(2)。

2. induction heating method as claimed in claim 1 is characterized in that,

The magnetic pole of described inductor is made of a plurality of.

3. induction heating method as claimed in claim 1 or 2 is characterized in that,

Described each coil is connected in series.

4. induction heating method as claimed in claim 1 or 2 is characterized in that,

Described its structure of each inductor is made and is utilized the lifting means to move along described thickness of slab direction by rolling sheets respectively.

5. induction heating method as claimed in claim 3 is characterized in that,

6. induction heating method as claimed in claim 1 or 2 is characterized in that,

By the direction of advance of rolling sheets two groups of described each inductors are set at least along described, described rollgang is configured between the described inductor.

7. induction heating method as claimed in claim 6 is characterized in that,

The iron core of described each inductor is arranged on the wide center line of described plate by rolling sheets.

8. induction heating method as claimed in claim 1 is characterized in that,

Described rollgang is coated in its surface with insulating material.

9. induction heating method as claimed in claim 7 is characterized in that,

The width unshakable in one's determination of described each inductor is got smaller or equal to the value of going from described plate reductions by rolling sheets behind the 300mm, and with described by the surperficial parallel direction of rolling sheets on, the distance between wide end of described plate by rolling sheets and described outer surface unshakable in one's determination is more than or equal to 150mm.

10. pressure-bearing type heating system; Many transverse type induction heating devices are arranged on the last process of described iron and steel hot rolling line between next procedure; Described transverse type induction heating device disposes by iron core between iron and steel hot rolling line roughing mill and finishing mill and is wound on the inductor that the coil on the iron core forms; Make it central across in opposite directions opposed by rolling sheets; Utilize the described inductor of ac power supply to described the heating by rolling sheets of rollgang conveying; It is characterized in that

δ＝{ρ/(μ·f·π)} ^1/2……(1)

1.0＜{cosh(tw/δ)+cos(tw/δ)}/2＜1.03……(2)