CN2419781Y

CN2419781Y - Electric water heating pipe

Info

Publication number: CN2419781Y
Application number: CN 00207385
Authority: CN
Inventors: 张伟
Original assignee: HEHE ELECTRIC APPLIANCES (HANGZHOU) CO Ltd
Current assignee: HANGZHOU KAWAI ELECTRICAL APPLIANCE CO., LTD.
Priority date: 2000-04-06
Filing date: 2000-04-06
Publication date: 2001-02-14
Anticipated expiration: 2010-04-06

Abstract

The utility model relates to the structure improvement of an electric heating pipe. The main improvement of the utility model is that the electric heating pipe is a double-layer pipe wall structure, and a metal outer pipe with smaller ductility is tightly sheathed with a metal inner pipe with greater ductility. Thus, under the premise that the magnesia powder in the electric heating pipe is ensured not to be affected with damp and electrical leakage, the utility model makes a damp-proof electric heating pipe with smaller curvature radius become possible, and the damp-proof electric heating pipe is made of materials (such as stainless steel) with poor ductility; simultaneously, integral strength and anticorrosion performance are enhanced and the service life is prolonged, which are favorable for the processing and the manufacture, and heat transfer performance is improved.

Description

Water heating electrothermal tube

The utility model relates to a kind of structural improvement of electrothermal tube.

Existing water heating electrothermal tube adopt the magnesia powder handled without silicon as insulation filler 6 '.Its advantage be since magnesia powder through silicon processing with ing, the electrothermal tube made from this kind magnesia powder can be directly with the metal tube 5 of individual layer ' carry out high-temperature heat treatment, so that be bent into different shape; But its shortcoming is to handle through silicon because of magnesium oxide powder very easily to make moist, and must seal two mouths of pipe with sealing 1, in case moisture enters in the electrothermal tube (referring to accompanying drawing 2).It is 100% qualified to be difficult to guarantee to seal from the joint filling material of present use and sealing tech, is difficult to promptly guarantee that magnesia powder does not make moist.To cause the electrothermal tube insulation resistance to descend in case magnesia powder makes moist, and produce leaky.

Insulation filler is if adopt the magnesia powder of handling through silicon, when metal outer pipe when filler being carried out compacting by the draw, tangible flow harden also takes place because of significant contraction in metal outer pipe, without high annealing, difficulty can be carried out bending tube forming; But if it is carried out high annealing, then can cause the magnesium oxide carbonization handled through silicon etc., make it to lose insulation effect.Therefore, at present, still adopt common magnesia powder to make filler, make, be bent into required shape after can adopting high annealing through the metal tube of the draw by a relatively large margin for the water heating electrothermal tube of need bending.

Someone has applied for the utility model of " polytetrafluoroethylene electric heating tube " (patent No. 97238048.5) by name, it comprises lead, pipe joint, electric heating tube, pipe joint is made up of connector cover, plinth, electric heating tube is coated with sheath by outer surface, in establish resistance wire metal tube constitute, two ends all place in the plinth, insert a binding post in it, and binding post and the resistance wire nut that linked is connected with lead.Owing to coated the polytetrafluoroethylmaterial material (temperature can reach 250 ℃) that one deck is high temperature resistant and be able to bear strong corrosion on the electric heating tube surface, solved not problem such as corrosion resistant defective of common metal material electric heating tube.But still it is relatively poor to exist moisture resistance, or is difficult to deficiencies such as bend pipe moulding.

Goal of the invention of the present utility model provides a kind of rational in infrastructure, and the life-span is long, and humidity resistance is good, and more easily is bent into the water heating electrothermal tube of required form.

Goal of the invention of the present utility model is to be achieved in that mainly described electrothermal tube is a double-layer tube wall structure, and the less metal outer pipe of described ductility tightly is placed in the bigger metal inner pipe of ductility.Usually, interior pipe can adopt iron pipe, aluminum pipe, copper pipe, and outer tube adopts stainless steel tube, because the former with the latter is compared and is had plasticity and toughness preferably, for the filler around the compacting heating wire effectively, contraction by a relatively large margin takes place in pipe in draw process, still can be bent into different shape; Stainless steel tube that ductility is relatively poor because the structure of pipe in being provided with greatly reduces the draw surplus of the directly tight pressing contact of inside and outside double layer of metal pipe, thereby makes stainless outer tube still can be bent into required shape even outer tube adopts bright corrosion-resistant.

Described metal inner pipe is a seamed metal tube, and its outer closely pressing has one deck seam metal outer pipe interlaced with each other, and the insulation filler that is equipped with in described metal inner pipe is that silicon is handled magnesia powder.Owing to adopted seamed metal tube, when reducing cost, interlaced arrangement has also improved the bulk strength of double-layer composite pipe.

In order to improve the constant intensity of heating tube (especially U type water heating tube), outside the end of described metal outer pipe, be with support set, the transverse plane of support set and the fixed flange of heating tube are fixedly connected.

Therefore, the utlity model has following advantage: 1. owing to realized handling the filler of magnesium powder, can guarantee fully that the magnesia powder in the electrothermal tube does not make moist leakproof as water heating electrothermal tube with silicon; And make the relatively poor material of employing ductility become possibility than the moistureproof electrothermal tube of small curvature radius.2. behind the employing bilayer sleeve, improved bulk strength, prolonged useful life, the protection that outer tracheal rupture or other reasons are caused was lost efficacy, and was still shielded by interior pipe, to increase the service life.3. improve antiseptic property, when being beneficial to processing and fabricating, also improving filler compactibility and whole heat transfer property.

Accompanying drawing 1 is a kind of partial structurtes schematic diagram with section of the present utility model.

Accompanying drawing 2 is a kind of partial structurtes schematic diagrames with section of the prior art.

Below by embodiment and accompanying drawing, the technical solution of the utility model is further described.

Embodiment: select for use external diameter be 8mm have the seam iron pipe do in pipe 5, insert in it heating wire 7 and with the electrode 8 that its end is connected to a fixed, pour into the magnesia powder handled through silicon on every side as insulation filler 6.External diameter with interior pipe 5 is contracted to 6.5mm again.Then it being penetrated internal diameter is the stainless steel outer tube 4 of 7.1mm, and the seam of two pipes is misplaced each other, outer tube 4 draws is managed on 5 in being closely pressed together on again.Compound thus bimetal pipe directly is bent into required U type pipe without annealing.The two ends of outer tube 8 place on the ring flange 2, and are provided with support set 3 outside it, with argon arc welding support set and outer tube are welded on the ring flange 2.Expose outside the metal tube end of described electrode 8, and the 1 employing silica gel that seals is therebetween made (as shown in Figure 1).

Claims

1. a water heats electrothermal tube, by electrothermal tube, be located at heating wire and the insulation filler in it and place the electrode of electric heating pipe end to constitute, it is characterized in that described electrothermal tube is a double-layer tube wall structure, and the less metal outer pipe (4) of described ductility tightly is placed in the bigger metal inner pipe of ductility (5).

2. water heating electrothermal tube as claimed in claim 1, it is characterized in that described metal inner pipe (5) is a seamed metal tube, its outer closely pressing has one deck seam metal outer pipe interlaced with each other (4), and the insulation filler (6) that is equipped with in described metal inner pipe is handled magnesia powder for silicon.

3. water heating electrothermal tube as claimed in claim 1 or 2 is characterized in that being with support set (3) outside the end of described metal outer pipe (4), the fixed flange (2) of the transverse plane of support set (3) and heating tube is fixedly connected.