CN105636256A

CN105636256A - High-temperature and high-pressure resistant electrical heater employing skin effect

Info

Publication number: CN105636256A
Application number: CN201610148303.7A
Authority: CN
Inventors: 戚洪明
Original assignee: HUANENG WUXI ELECTROTHERMAL EQUIPMENT CO Ltd
Current assignee: HUANENG WUXI ELECTROTHERMAL EQUIPMENT CO Ltd
Priority date: 2016-03-15
Filing date: 2016-03-15
Publication date: 2016-06-01

Abstract

The invention relates to the technical field of industrial electrical heating for processes, in particular to an electrical heater fabricated by a principle of a skin effect. The electrical heater comprises a metal U-shaped pipe body, wherein a heating cable is arranged in the U-shaped pipe body; two ends of the heating cable are connected with a phase line and a zero line respectively; the middle part of the U-shaped pipe body is grounded; a stainless steel pipe is arranged at one end, close to two pipe orifices, of the U-shaped pipe body; a nickel pipe is arranged at the other part of the U-shaped pipe body; an inner core of the heating cable is a nickel-chromium core; the diameter of the stainless steel pipe is greater than that of the nickel pipe; the pipe orifice of the U-shaped pipe body is connected with a pipe plate; and a connection box is arranged at a terminal of the heating cable. By the principle of the skin effect, heating of the nickel pipe is partial heating source; an electric heating pipe is low in calorific value; and a system is long in lifetime. The heating pipe is formed by welding different materials; and the heating problem of a cold end of the heating pipe is reduced. A solid nickel-chromium alloy is adopted by the cable, so that the current-carrying capacity is high; and the temperature resistance and the oxidation resistance are high.

Description

High temperature high voltage resistant skin effect electric heater

Technical field

The present invention relates to industrial process electric-heating technology field, especially a kind of electric heater utilizing skin effect principle to make.

Background technology

Existing industrial electro well heater often adopts the structure of circulation heater, is insert boundling electrothermal tube structure in the container of a kind of band import and export. Fluid and cluster type electric heating pipe carry out the object that heat exchange reaches gas and heated. The major defect of this structure is:

1, owing to electricity inside heat pipe adopts tiny nichrome wire, it is easy to blow and 100% depend on electrothermal wire heating to become.

2, usually need to adopt a large amount of electric heating pipes to be assembled.

3, due to the restriction of electric heating pipe string diameter, working temperature can not be too high.

4, adopting a large amount of electric heating pipes, the weld of electric heating tube hydroforming is many, also easily leaks, and uses problem more outstanding in high temperature, high pressure occasion. .

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of electric heater, has the feature of high temperature high voltage resistant.

In order to solve the problems of the technologies described above, the present invention comprises metal U-tube body, is provided with heating cable in described U-tube body, and the two ends of described heating cable are connected with phase line and zero line respectively, the middle position ground connection of described U-tube body.

Preferentially, described U-tube body is stainless steel tube near one end of two mouths of pipe, and other parts of described U-tube body are nickel pipe.

Preferably, the interior core of described heating cable is nickel chromium core.

Preferably, the diameter of described stainless steel tube is greater than the diameter of nickel pipe.

Further, the mouth of pipe of described U-tube body is connected with tube sheet, and the wiring end of described heating cable is provided with terminal box.

The Advantageous Effects of the present invention is:

1, utilize the principle of skin effect, the heating of nickel pipe is part heating source, and electric heating pipe thermal value is few, and lifetime of system is long.

2, heat-generating pipe adopts different materials to be welded, and reduces the heating problem of heat-generating pipe cold junction, and power cable and terminal box are not easily damaged.

3, cable adopts the nichrome of real core, and current capacity is big, and resistance to gentle antioxidant property is strong.

Accompanying drawing explanation

Fig. 1 is the structural representation of the present invention.

Embodiment

Embodiment cited by the present invention; just understand the present invention for helping; should not be construed as limiting the scope of the present invention; for those skilled in the art; without departing from the inventive concept of the premise; the present invention can also being improved and modify, these improve and modify in the scope also falling into the claims in the present invention protection.

As shown in Figure 1, the present invention comprises metal U-tube body, described U-tube body is stainless steel tube 2 near one end of two mouths of pipe, other parts of described U-tube body are nickel pipe 3, and described stainless steel tube and nickel pipe are processed into by thick-walled tube, and the diameter of described stainless steel tube is greater than the diameter of nickel pipe. Being provided with the heating cable 1 that interior core is nickel chromium core in described U-tube body, temperature resistant grade is up to 1200 degree, and current capacity height, output rating is big. The two ends of described heating cable 1 are connected with phase line and zero line respectively, the middle position ground connection of described U-tube body. The mouth of pipe of described U-tube body is connected with tube sheet 4, and the wiring end of described heating cable 1 is provided with terminal box 5, and terminal box is provided with the import 6 of power cable, and described power cable is connected with heating cable 1 by import 6.

The present invention is installed with heating cables in U-tube body, the high temperature fluoroplastic cable that this cable is different from common SECT system is the mineral cable or electric heating pipe that adopt, and cable core wherein adopts solid nickel chromium core pole, current capacity is big, temperature resistant grade height.

U-tube body adopts stainless steel pipe and nickel pipe to be welded, nickel pipe is adopted to be consider its magnetic permeability height, it is that its magnetic permeability is low that stainless steel tube is considered, the magnetic permeability utilizing bi-material different produces different skin depths, producing different thermal values, due to stainless material, to have magnetic permeability low, skin depth height, the feature that thermal value is low, is therefore used as cold junction by stainless steel tube.

The example of the present invention is the nickel pipe adopting �� 22 �� 3, and the heat generating core in electric heating pipe is the nichrome wire of �� 5, and actual measurement electric heating pipe heating accounts for the energy of 80%, owing to skin effect accounts for the energy of 20%. Heat generating core resistance is more little, and the energy proportion that the heating of nickel pipe accounts for is more big, and as adopted copper rod, the thermal value of nickel pipe to be accounted for the energy of 64%, also to be considered the heatproof situation of system selection in certainly specifically using.

Heating cable in example have employed solid nickel chromium core pole, and single root heating tube resistance is very little, and distribution can be considered: 1, adopts SCR control, applies low voltage, big current. 2, the many electric heating pipe after-applied conventional voltages of series connection are adopted, such as: 220V. As adopted variable frequency control, the heating effect of nickel pipe will be more obvious.

Owing to the nickel pipe of the end that generates heat is the part source generated heat in skin effect, reduces the thermal value of its pocketed heat cable, extend the work-ing life of system.

Claims

1. high temperature high voltage resistant skin effect electric heater, it is characterized in that, comprise metal U-tube body, in described U-tube body, be provided with heating cable (1), the two ends of described heating cable (1) are connected with phase line and zero line respectively, the middle position ground connection of described U-tube body.

2. high temperature high voltage resistant skin effect electric heater according to claim 1, it is characterised in that, described U-tube body is stainless steel tube (2) near one end of two mouths of pipe, and other parts of described U-tube body are nickel pipe (3).

3. high temperature high voltage resistant skin effect electric heater according to claim 2, it is characterised in that, the interior core of described heating cable is nickel chromium core.

4. high temperature high voltage resistant skin effect electric heater according to claim 3, it is characterised in that, the diameter of described stainless steel tube is greater than the diameter of nickel pipe.

5. high temperature high voltage resistant skin effect electric heater according to claim 3, it is characterised in that, the mouth of pipe of described U-tube body is connected with tube sheet (4), and the wiring end of described heating cable (1) is provided with terminal box (5).