CN2324744Y

CN2324744Y - Double-insulation electric heater

Info

Publication number: CN2324744Y
Application number: CN 97224405
Authority: CN
Inventors: 赵建国
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-08-10
Filing date: 1997-08-10
Publication date: 1999-06-16
Anticipated expiration: 2007-08-10

Abstract

The utility model relates to a double-insulation electric heater, belonging to an electro-heat transfer device, which omits the processes of reducing the diameter and welding heat emission fin sealing, etc. at the manufacture time. The structure of the utility model is that the outer surface of a common metal electric-heat pipe is coated with a continuous and uniform inorganic rubber film with phosphoric acid copper monoxide layer, then, is capsulated in zero clearance in a metal outer jacket, and thereby, the double earth leakage protection is formed between a part with electricity and a metal sheath at the outer layer. The inner surface of the outer jacket is similar to the outside surface of the common electric-heat pipe. The outer surface can have various styles, and can be a tubular shape, a bellows shape, a fin shape, a disk shape, etc.

Description

A kind of double insulation electric heater

The utility model belongs to the electrical heating elements class, and dual earth leakage protective electric heater especially can be provided:

In the double insulation electrothermal tube of former invention, as the joint structure of being chatted among Chinese patent ZL93241856.2 and the ZL94218994.9 (seeing 26 pages-27 pages of " household electrical appliance science and technology " 96.4 phases), be the common electrical heat pipe and outside inner room filling powder shape magnesium oxide or liquid heat conductive oil as the supplementary insulation heat-conducting medium.So there is following shortcoming, when outer casing rupture, supplementary insulation lost efficacy at once, and owing to have air gap in the magnesia powder, thereby thermal resistance is bigger, needs to increase radiating fin and improves radiating effect, but also need diameter reducing process, and sealing process, the principle of wherein narrating is difficult to be applied to resemble in the foundry element of electric rice cooker heating plate class.

The purpose of this utility model: provide a kind of double insulation electric heater, its outer during fabrication tubular sheath does not need undergauge and weldering radiating fin, technology such as seals and can be applicable in the element such as foundry heating plate, for it provides dual earth leakage protective.

The purpose of this utility model is such realization: be to make certain thickness phosphoric acid-cupric oxide insulating heat-conductive film fully continuously equably in common metal electrothermal tube appearance; then it seamlessly is encapsulated in the tubular metal overcoat; and by phosphoric acid-cupric oxide inorganic adhesive film; make common electrical heat pipe sheath and outer protective sleeve keep certain dielectric strength, thereby constitute dual earth leakage protective between live part (resistance wire) and outer layer metal sheath.After to the resistance wire energising; do the basic insulation of resistance wire by the magnesium oxide in the common electrical heat pipe; after basic insulation lost efficacy because of certain reason; make the outer casing electrification of common electrical heat pipe; at this moment the insulation between electrified body and outer protective sleeve is just worked by the supplementary insulation that phosphoric acid-the cupric oxide inorganic adhesive film constitutes during filling; make outer protective sleeve not charged, thereby form dual earth leakage protective.Because the electric simulation strength of phosphoric acid-cupric oxide inorganic adhesive film is greater than magnesia powder, thereby under equal electric index, the thickness of phosphoric acid-cupric oxide glued membrane is less, and its heat conductivility is better than magnesia powder, improves radiating effect so need not to increase radiating fin.Only need to get final product to groove or axial striped at outer jacket outer surface swing over compound rest, because glued membrane is continuous atresia, break even shell has slightly again, supplementary insulation can not lose efficacy at once.

Owing to adopt such scheme, can when making the double insulation electric heater, omit technologies such as undergauge weldering radiating fin seals, saving of work and time reduces cost, and can be applicable in the foundry element.

Below in conjunction with drawings and Examples the utility model is further specified.

Fig. 1: the vertical section structural map that is dual exhausted first embodiment of electrothermal tube.

Fig. 2: the A-A ' profile that is Fig. 1.

Fig. 3: the embodiment footpath profile that is the double insulation electric hot tray.

Among Fig. 1 and 2: 1 is phosphoric acid-cupric oxide inorganic adhesive film; 2 is starlike outer tube layer sheath; 3 magnesium oxide; 4 resistance wires; 5 threaded sleeves; 6 extraction electrodes; 7 common electrical heat pipe metal shells.

In Fig. 3: 1 is phosphoric acid-cupric oxide, the insulation glued membrane; 2 is common metal pipe overcoat; 3 is heating plate; 4 is heating wire; 5 is magnesium oxide.

1, Fig. 1 and Fig. 2 embodiment: be applied in the shell-type electric heating element, the common electrical heat pipe shell 7 equal unoccupied places of degreasing and rust removal are placed in the starlike outer tube layer sheath 2, and make its gap in 1 millimeter, fill up deployed phosphoric acid-cupric oxide inorganic adhesive film 1 betwixt, and make common tubular heater 7 stretch out shell 2, length is not less than 4 millimeters, to satisfy of the requirement of II electric appliances to creepage distance and electric clearance, and make extension also cover inorganic glued membrane, to improve dielectric strength, can use after placement is at room temperature solidified after the filling.

Because inorganic glue is high temperature resistant, generally can reach more than 700 ℃, as add zirconia powder etc. in glue, its fusing point can reach more than 1000 ℃, so electrothermal tube can worked below 500 ℃ for a long time.

2, Fig. 3 embodiment is applied in the electric hot tray

Its structure such as Fig. 3, with the outer wall 2 of common electrical heat pipe, surface degreasing rust cleaning and sandblast are to improve surface roughness, to improve the adhesive strength of glued membrane earlier.Be coated with the phosphoric acid that a layer thickness is the 0.5-1 millimeter-cupric oxide inoranic membrane 1 then on its surface.After treating its freezing film, can resemble cast form the common electric heating.Because glued membrane generally can only anti-high temperature below 1000 ℃, generally can be used for fusing point 900 ℃ of following alloy disc.

Claims

1, be to make the solid-state supplementary insulation conductive adhesive film that certain thickness satisfies certain electric index request more fully continuously equably at the common electrical heat pipe outer surface; seamlessly be encapsulated in it in metal-coating; and make common electrical heat pipe metallic sheath and outer protective sleeve keep certain dielectric strength by the insulating heat-conductive glued membrane; thereby constitute dual earth leakage protective between live part (resistance wire) and outer layer metal sheath, it is characterized in that: its insulating heat-conductive glued membrane uses phosphoric acid-cupric oxide inorganic adhesive film.

2, double insulation electric heater according to claim 1 is characterized in that: add 5%-30% weight portion 200 in phosphoric acid-cupric oxide inorganic adhesive film liquid ^#The zirconium powder of above granularity is as its supplementary insulation glued membrane medium.

3, according to claim 1,2 described double insulation electric heaters, it is characterized in that: the outer layer metal jacket inner surface is similar to common electrical heat pipe metal shell outer surface, and outer surface is cylindrical.

4, it is characterized in that according to claim 1,2 described dual electrothermal tubes: the outer layer metal jacket outer surface is shaped on axial radiating ribs or is shaped on radially screw thread or ripple.

5, according to claim 1,2 described double insulation electric heaters, it is characterized in that: its outer sheath is the casting of metals disk body.