WO2004082335A1

WO2004082335A1 - Electric heating cable with reduced emf emissions

Info

Publication number: WO2004082335A1
Application number: PCT/KR2003/002291
Authority: WO
Inventors: Tae-Ha Lee
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-03-11
Filing date: 2003-10-29
Publication date: 2004-09-23
Anticipated expiration: 2005-09-11
Also published as: KR200317436Y1; AU2003274772A1

Abstract

An electric heating cable maximizing a function of shielding harmful electric and magnetic fields as a inherent function and minimizing the damage of human body by the harmful electric and magnetic fields. In order to achieve the above object, the electric heating cable minimizing harmful emanation of electric and magnetic fields therefrom, comprises; heating wire member (10), including: carbon wire windings formed as a plurality of thin wires are formed; and first wrapper (4) wrapping the carbon wire windings so as to electrically insulate; non-resistive wire member (20), including: non-resistive wire (12) formed as a plurality of thin conducting wires are twisted; and second wrapper (14) wrapping the non-resistive wire (12) so as to electrically insulate; wire member (30) for absorbing electric and magnetic fields, the wire member (30) is formed as conductive silicon solidifies on the heat wire member (10) and the non-resistive member (20) after coating thereon.

Description

ELECTRIC HEATING CABLE WITH REDUCED EMF EMISSIONS

TECHNICAL FIELD

The present invention relates to an electric heating cable for heating an object, and more particularly, to an electric heating cable minimizing harmful emanation of electric and magnetic fields therefrom, when generating electric resistive heating.

BACKGROUND ART Generally, there are several methods for generating electric heat. For example, an electric resistive heat is generated from an electric heat wire through which electric current passes, an arc heat is produced by arc discharge from electrodes through which electric current passes, and induction heat is created from an object such as metal or conductive material as electric current pass through the object in which electrical induction operation occurs.

The restive heating is divided into a direct resistive heating and an indirect resistive heating. The direct resistive heating means that an object is heated as electric current directly flows along the object, and the indirect resistive heating means that an object is heated by way of heat emission and heat transfer as electric current flows within a metal resistive wire or non-metal heating body such as SiC contacting the object.

There are various applications using the indirect resistive heat, for example, electrical rice cooker, electrical heating appliance, electrical iron and electrical heating fan etc. Using petroleum or natural gas as heating fuel is not efficient but also brings about harmful gas to environments when it burns. By the way, since using a late-night electricity maximizes the efficiency of energy usage, recently an electrical appliance is used for the indirect heating of heating methods.

When heating an object using the late-night electricity, we needs an electrical heating apparatus including an electric heating cable converting the electricity to heat energy, which prevents from an electric leakage.

If an electrical heating apparatus is used for heating way by electric energy, it must have a heating wire converting electrical energy into heat energy and an insulator for preventing electric current leakage from the heating wire.

The electric heating wire installed into the electric heating apparatus is a cable made of Ni-Cr alloy/ Fe-Cr alloy under the temperature less than 1000°C, a cable made of SiC/Kanthal etc. higher than 1000°C, and Molybden Silicade more than 1400°C. Especially, in order to obtain electric heat a core wire made of metal such as Ni or Cr has just been wrapped.

However, it is well known to emit harmful electric and magnetic fields (EMF) from the electric heat wire, there has been studied to reduce the harmful EMF. In Korean Utility Model, Registration No. 192649, an electric heat cable for shielding EMF is proposed. As shown in Figure 1 , the structure of the electric heat cable includes electric heat wire 10, fluorocarbon (Teflon) insulation layer 12 wrapping the electric heat wire 10, insulating tape 14 wrapping the fluorocarbon insulating tape 12, Aluminum tape layer 16 wrapping the insulating tape 14, weaved layer 18 wrapping the Aluminum tape layer 16, insulating layer 20 wrapping the weaved layer 18. The electric heat wire 10 is formed as Ni-Cr alloy wire of 3 to 15 are twisted, the fluorocarbon insulation layer 12 is formed to have a predetermined insulation endurance pressure as the fluorocarbon is pressed.

The Aluminum tape layer 16 increases insulation endurance pressure of the fluorocarbon isolation layer 12 and absorbs the electric and magnetic fields emitted from the eiectric heat wire 10.

When an electrical power is applied to the electric heat wire 10, in order to absorb the electric and magnetic fields therefrom and to effectively emit the electrical heat therefrom, the weaved layer 18 is wrapped on the Aluminum tape layer 16, and the insulation layer 20 wrapped on the weaved layer 18 is formed as Silicon rubber is pressed. Also, the weaved layer 18 is weaved by copper wires which coated with tin (Sn) for strain.

Even though the prior art electric heat cable is formed to absorb the EMF by the Aluminum tape layer 16, and the Aluminum tape layer 16 can increase the insulation endurance pressure of the fluorocarbon insulation layer 12, therefore they can not effectively remove the harmful EMF.

Therefore, in order to solve the problem of the technique disclosed in the Korean Utility Model, Registration number 192649, there is another embodiment disclosed in the Korean Utility Model, Registration No. 249031 , which structure is shown in Figure 2. Namely, the winding core 11 made of non-resistive copper wires of 20 ~ 30 is wrapped by wrapping layer 12-1 such as fluorocarbon or Nylon. The wrapping layer 12-1 is spirally wounded by the heating conductor 13 soldered thereto.

The heating conductor 13 is wrapped with the wrapping layer 12-2 such as nylon wraps again. The temperature detecting conductor 14 spirally winds on the wrapping layer 12-2. The temperature detecting conductor 14 is wrapped by an insulation layer 15 such as PVC. From the above construction, when electric current flows along the winding core 11 and the heating conductor 13 for a predetermined time, the temperature of the heating conductor 13 increases, the impedance change of the wrapping layer 12-1 resulted from the temperature change of the heating conductor 13 is detected by the temperature detecting conductor 14. The electric current flowing along the heating conductor 13 is controlled by the controller inputting a detection value.

The technique disclosed in Korean Utility Model, Registration No. 249031 , can detect noise power smaller 10~20 dBdW than general noise power, but the factors for detecting the relatively smaller noise power can not remove the harmful EMF.

Meanwhile, as shown in Figure 3, the Korean Utility Model, Registration

No. 233539, discloses a heat wire made of Carbon wire which was known to emit the EMF relatively small. The glass fiber 70 wraps on the outer surface of a plurality of carbon wires 60.

The carbon wires 60 and the glass fiber 70 are wrapped by Silicon on their outer surfaces, the outer surface of the Silicon 20 is wrapped by glass fiber net 30, the glass fiber net 30 is wrapped by a plurality of copper wires 40. The glass fiber net 30 and the copper wires 40 are wrapped by silicon 5. Here, the winding number of carbon wires may include 2,400 and the number of the copper wires 40 may include 3.

As disclosed in the Korean Utility Model, Registration No. 233539, since the electric heat wire adopting carbon wires 60 emits the EMF relatively small and the copper wire 40 in insulation state is wound spirally, its EMF emissions can be reduced comparing other prior arts. But it never propose any elements for shielding the EMF emissions.

Also, as shown in Figure 4A, the prior art electric heat wire is electric heat wires 60, 70 connected to each other in parallel, of which outer surface is wound by non-restive wire 40-1 , or as shown in Figures 4B and 4C, non- resistive heat wire 40-1 electrically connected to the electric heat wire 10 winding the outer surface thereof. But the prior art electric heat wires does not shield the emissions of the EMF and electrical waves.

DETAILED DESCRIPTION OF THE INVENTION

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an electric heating cable maximizing a function of shielding harmful electric and magnetic fields as a inherent function and minimizing the damage of human body by the harmful electric and magnetic fields.

In order to achieve the above object, the electric heating cable minimizing harmful emanation of electric and magnetic fields therefrom, comprises; heating wire member (10), including: carbon wire windings formed as a plurality of thin wires are formed; and first wrapper (4) wrapping the carbon wire windings so as to electrically insulate; non-resistive wire member (20), including: non-resistive wire (12) formed as a plurality of thin conducting wires are twisted; and second wrapper (14) wrapping the non-resistive wire (12) so as to electrically insulate; wire member (30) for absorbing electric and magnetic fields, the wire member (30) is formed as conductive silicon solidifies on the heat wire member (10) and the non-resistive member (20) after coating thereon. As another embodiment, the heating wire member (10), non-resistive wire member (20) and the wire member for absorbing electric and magnetic fields are further wrapped a third wrapper (40).

As further another embodiment, the plurality of wrapping materials (4, 14, 24, 40) is made of Silicon.

As still another embodiment, the plurality of wrapping materials (4, 14, 24, 40) is made of fluorocarbon.

As other embodiment, the plurality of wrapping materials (4, 14, 24, 40) is made of nonflammable PVC. As further other embodiment, the wire member (30) for absorbing electric and magnetic fields is 2mm thick.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:

Figure 1 is a schematic view showing a construction of the prior art heating cable according to the first embodiment;

Figure 2 is a schematic view showing a construction of the prior art heating cable according to the second embodiment;

Figure 3 is a schematic view showing a construction of the prior art heating cable according to the third embodiment; Figures 4A to 4C are connection views of the prior art heating cables; Figure 5 is a connection view of the heating cable with reduced EMF emissions according to the present invention; and

Figure 6 is a partially cross-sectional view of the electric heating cable with reduced EMF emissions according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to Figures 4A to 6, the preferred embodiment of the present invention will be explained below:

As shown in Figure 6, the present invention is related to an electric heating cable with reduced EMF emissions includes heating wire member 10 generating resistive heat according to inputting electric current thereto under the isolation state, non-resistive wire member 20 capable of flowing the electric current under the isolation state, and conduction wire member 30 for absorbing electric and magnetic fields capable of flowing the electric current under the isolation state.

As shown in Figure 5, under the state that the heating wire member 10 and the non-resistive wire member 20 are spirally twisted each other extending along one end to the other, the heating wire member 10 and the non-resistive wire member 20 are wrapped by the conduction wire member 30 for absorbing the electric and magnetic fields of which both ends are electrically grounded.

Here, as shown in Figure 6, the heating wire member 10 is constructed as a plurality of thin Carbon wires 2 are folded and a wrapper 4 electrically insulates them. Also, the non-resistive wire member 20 is constructed as a plurality of thin non-resistive conduction wires 12 are spirally twisted and a wrapper 14 electrically insulates them. The conduction wire member 30 for absorbing the EMF is formed as conductive silicon is coated on the outer surface of the heating wire member 10 and the non-resistive wire member 20 and then hardened, as shown in Figure 6. Also, the heating wire member 10, the non-resistive wire member 20 and the conduction wire member 30 for absorbing the EMF are wrapped by another wrapping materials 40. Here, the conduction wire member 30 for absorbing the EMF is preferably 2mm thick.

The heating wire as constructed above has characteristics as shown in the following table 1 , which is obtained from a test result.

[Table 1*]

* Table 1 is a tested performance certified by the name of the present of Korea Electric Testing Institute

As shown in table 2 below, regarding a plurality of the predetermined positions over the entire length, the magnetic field average detecting value is 616.84[ μ G], and the electric field average detecting value is 4.5839[V/m]. These average values are within the reference values, the electric field value of under 10V/m and the electric field value of under 2mG and means that the heating wire is good to perform. [Table 2]

The following Table 3-1 shows a graph of relationship between the magnetic field values of plural measurements in a predetermined first position of the entire length of the heating wire and the frequencies corresponding to the magnetic field values. The following table 3-2 is tabled from Table 3-1. Here, the maximum value of the detected magnetic field is 620.32[ μ G] and the maximum frequency is 3.7881 Hz corresponding thereto.

[Table 3-1]

MB»:».D V,MCD__J^SP. JSAΪ&RWE aXS9MS£.£ n ir is

[Table 3-2]

DCWB: EF^-3QC! F-0034, PROBE' BC PRB ?, CH ALL 'Z\ L 20, O' UI D FΓT t .TETO)E.2G0 01 a_S 31t.1T, 16

F RΛNΘE' 5UI.2 _t Ll&K: LIVE, VALID, O OFJHZ] 1 , DET, AVΘ

The following Table 4-1 shows a graph of relationship between the magnetic field values of plural measurements in a predetermined second position of the entire length of the heating wire and the frequencies corresponding to the magnetic field values. The following table 4-2 is tabled from Table 4-1. Here, the maximum value of the detected magnetic field is 539.65[ μ G] and the maximum frequency is 3.7796Hz corresponding thereto.

[Table 4-1]

DiVloE- l_fA-SCO ^8'«034.l»R<-JHEf' e>3^' P« f.ftHi AU,

\<Sh/# 2i , a v, fcooε r«^*

-ATCIf C IXC M' 4ϊ '_23 V ?l ^l "•

* mε, β ..a Hι,m u t,^,f-_j OK -IH-I ι.t=τ A,S

[Table 4-2]

OeuTc* EFΛ- 30σ ND34. PROBE: EXT PUB 2_S CHN: ALL

MEM* 21 , D; V, MODE: FFT

PATff«£; 2W3-Q1-2S/S 11:23:58

F RANGE 5Hz._2KHz, M X. LIVE, VALID, UK_a DP(HZ|^< 1, OBT. AVC

The following Table 5-1 shows a graph of relationship between the magnetic field values of plural measurements in a predetermined third position of the entire length of the heating wire and the frequencies corresponding to the magnetic field values. The following table 5-2 is tabled from Table 5-1. Here, the maximum value of the detected magnetic field is 626.28[ μ G] and the maximum frequency is 3.7925Hz corresponding thereto.

[Table 5-1]

[Table 5-2]

Da TO: eFA-SOd P-0034, PK β BO^* PRB 2, CHI 41

MHVtt.22, 0 V, ivlODE: FFT

DATBTJME.2003-01 -25/S.S 11:2528

F RANGE: 5Hz..2 Hz_f MA: UYE, VALID; OK, DF|HZJ 1 , DET, AVG

The following Table 6-1 shows a graph of relationship between the magnetic field values of plural measurements in a predetermined fourth position of the entire length of the heating wire and the frequencies corresponding to the magnetic field values. The following table 6-2 is tabled from Table 6-1. Here, the maximum value of the detected magnetic field is 609.02[ μ G] and the maximum frequency is 3.7653Hz corresponding thereto.

[Table 6-1]

r'SMtf 2Jr, P V, ιV:_!E FT r OAK'S, mi J.--.;, MS ; tf-E, yAUD; CI., ξr_,HZ; <ι. PET AV«

[Table 6-2]

Dαfce: EFA-IQQ F.Q03 , PR08S- &J PR8 2, CHN' ALL

MBM& 23_k 0. V. MODE: FFT

DATE/TIME: 2003-D1-2S/≤S 1 1:28:S0

F ΪANSE: 5HJS„2KB2, MAX; LIVE, VAUO: O , DF|HZj: 1 , DET; AVG

The following Table 7-1 shows a graph of relationship between the magnetic field values of plural measurements in a predetermined fifth position of the entire length of the heating wire and the frequencies corresponding to the magnetic field values. The following table 7-2 is tabled from Table 7-1. Here, the maximum value of the detected magnetic field is 634.94 [ μ G] and the maximum frequency is 3.7929Hz corresponding thereto.

[Table 7-1]

0*»» ffA-a-Q r-Jg&i , ΦSQ h. fcS^* Pf® X <SHH AIL wwr a , u v, M 351? FFF " βMfirtME _aθ_u3i-2&__.ϊ ? ! ».*

FJΪASKSS.56*-, JtfHj, h_AS_ tjy= VM -, C^₍ PFlrøJ, 1 ,0ET. AV$

[Table 7-2]

Device: EFA--3Q0 F-Q034, PROBE EXT PRB 2, CBM Ait 24, D V, MODE: FFT

P^βJFflT 1Eι :D03.' 1 5 ^<2Q 1 1:2;'<15

F RAS&Ξ. SH∑..^"KH:, tø4& UVE. VALD: , CF[H2) f _t DET. C-

The following Table 8-1 shows a graph of relationship between the magnetic field values of plural measurements in a predetermined sixth position of the entire length of the heating wire and the frequencies corresponding to the magnetic field values. The following table 8-2 is tabled from Table 8-1. Here, the maximum value of the detected magnetic field is 5.3649[ μ G] and the maximum frequency is 60.05Hz corresponding thereto.

[Table 8-1]

0¥sror-sFA-i01f-aQ?M, P»3BE: --^ϊ Vp , fit tf^"W Ϊ ΪW.MCOS tf^" πftτ__«_6,a_»iϊi«aέa w z ρjm®s CH* ?wsr,i*v: uvπ w p srpi? \ •

[Table 8-2]

Dewrø; EFA-300 F B34, PROBE; EFJΗS* CH1Ψ ALL

MBU 2_f D: V, MODE FFT

QATEfflMEi 2Q03-01-2S/SS 10^*33;QS .RAM66; 5Hϊ..2KHz, MAX: UVE, VAUλ OK, DFft-fZ 1 , OET AVG

The following Table 9-1 shows a graph of relationship between the magnetic field values of plural measurements in a predetermined seventh position of the entire length of the heating wire and the frequencies corresponding to the magnetic field values. The following table 9-2 is tabled from Table 9-1. Here, the maximum value of the detected magnetic field is 6.5026[ μ G] and the maximum frequency is 59.963Hz corresponding thereto.

[Table 9-1]

C5«l» EF/ MPW34, PROSE BP MS, Of* AJL ffitm 3, 0 V, MOOE FFT ewer* :«a«-asss toice

FJWISG 5H*.2H. _<S*W£ UVE. VALID: GK.SPjtfij, 1 ,, BET. AV6

[Table 9-2]

Oβ'HCβ B ςOO F-QC^, P.ΪOSE: EF Pfia, CM.L. 1

"*€f'f:3,D .^".MODE FF

DΑTBTItøE 2C03H31-25/2£_S I0J2.42

F Wi fcS SHϊ, JKHz. MAX Lϊ'E, VAJJO OK, DF[H2j 1 , DEI. AVG

The following Table 10-1 shows a graph of relationship between the magnetic field values of plural measurements in a predetermined eighth position of the entire length of the heating wire and the frequencies corresponding to the magnetic field values. The following table 10-2 is tabled from Table 10-1. Here, the maximum value of the detected magnetic field is 1.3055[ μ G] and the maximum frequency is 59.958Hz corresponding thereto.

[Table 10-1]

RrvsP erΛ.-_tffl F3_34_.*WξS EFJWIB CHrfΑLl f&Mr a D. V, fβ3E r=τ

P AT BTCW 30Q3.C? 'S 13« |β

[Table 10-2]

Device: EFA-^OC' F-003 , PROBE EF PRB, OHM; ALL MEM* Θ. & V, MODE FFT

DATETOfi. 2003-01 -2§/≤ 13 10^*40-38

F A Se; 5Hz..2KHs_t MAX. LIVE, VAUDi OK, PF(HZ]: 1 , DET; AVΘ

The following Table 11-1 shows a graph of relationship between the magnetic field values of plural measurements in a predetermined ninth position of the entire length of the heating wire and the frequencies corresponding to the magnetic field values. The following table 11-2 is tabled from Table 11-1. Here, the maximum value of the detected magnetic field is 3.4744[ μ G] and the maximum frequency is 60.025Hz corresponding thereto.

[Table 11-1]

U«tø 6FrfV3MF«M, PROSE pr PRB.C ΛL mm 4, ϋ>.^, . -rt tj i ***^• «A,IAS i ,vmn e . GFjnr_. \D_-r t

[Table 11-2]

OI Λ Cf A- 50ύ r-O 3 , PR€PP ~F PPP, CHι*t: r LL

ME fc Q: , MODE FFT

OAΪEnTfcΕ. lC€EM)1^«liS/f2δ! 10 -M.OQ

The following Table 12-1 shows a graph of relationship between the magnetic field values of plural measurements in a predetermined tenth position of the entire length of the heating wire and the frequencies corresponding to the magnetic field values. The following table 12-2 is tabled from Table 12-1. Here, the maximum value of the detected magnetic field is 6.2724[μG] and the maximum frequency is 60.026Hz corresponding thereto.

[Table 12-1]

t«_cΛ%iE itts*-:M-_®o«! _ft m lerate ;' ^fs,ι_JW;Lr-. wιiD,c o?|H?f 8, rør ΛVΓ_*

[Table 12-2]

Device; EFA-30O F-QQ34, PROBE' EF.FKB, CHN: ALL m 7, D: V, MODE; FFT

DATS/ME 20D_HJ1-2&ffiδ 10.4703

F ANΘ& 5Hz..2Wte_J «C UVE, VALID' OK, OFJHXJ 1 , DET:

INDUSTRIAL APPLICABILITY As so far described, according to the present invention, the electric heating cable made of Carbon wires known to emit the EMF relatively smaller is formed like the carbon wires are spirally twisted and the twisted Carbon wires are wrapped by silicon, accordingly it can reduce the emissions of the harmful EMF therefrom, thereby minimizing the damage of humans. As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalence of such meets and bounds are therefore intended to be embraced by the appended claims.

Claims

1. An electric heating cable minimizing harmful emanation of electric and magnetic fields therefrom, comprising: heating wire member (10), including: carbon wire windings formed as a plurality of thin wires are formed; and first wrapper (4) wrapping the carbon wire windings so as to electrically insulate; non-resistive wire member (20), including: non-resistive wire (12) formed as a plurality of thin conducting wires are twisted; and second wrapper (14) wrapping the non-resistive wire (12) so as to electrically insulate; wire member (30) for absorbing electric and magnetic fields, the wire member (30) is formed as conductive silicon solidifies on the heat wire member (10) and the non-resistive member (20) after coating thereon.

2. The electric heating cable according to claim 1 , the heating wire member (10), non-resistive wire member (20) and the wire member for absorbing electric and magnetic fields are further wrapped a third wrapper (40).

3. The electric heating cable according to claim 1 , the wire member (30) for absorbing electric and magnetic fields is 2mm thick.