RU2251823C2 - Flexible inductor for heating cylindrical bodies - Google Patents

Abstract

FIELD: low-temperature inductive heating of pipes, tanks, turbogenerator sleeve tubes, and other cylindrical bodies.

SUBSTANCE: proposed flexible inductor has inducing conductor and conductor ends bracing device; conductor is made in the form of strip furnished with tensioning facility; strip ends are meant for connection to power supply. Strip may be covered with electric current insulating, heat conducting, and heat insulating layers. Strip may be made of separate strip lengths.

EFFECT: enhanced uniformity of heating surfaces of cylindrical bodies of various diameters.

1 cl, 4 dwg

Description

The invention relates to electrical engineering and can be used for low-temperature induction heating of pipelines, tanks, retaining rings of turbogenerators and other cylindrical bodies.

Known flexible inductor designed to heat an object, such as a pipe, made in the form of a flexible water-cooled cable, freely wound around the object and connected to a power source [1].

The disadvantages of this design are low efficiency, uneven heating of the surface of the object, the need for water cooling of the induction cable, the difficulty of concentration of heating in the required zone.

Closest to the claimed device is a flexible inductor containing an induction wire with current leads for connecting to a power source, and the induction wire is made in the form of a multicore cable, the cores of which are connected together in series by means of a tightening device made in the form of a plug connector. Current leads are installed on the first and last cores [2].

This flexible inductor is convenient for operation, since it does not require water cooling. However, it does not allow evenly heating the surface of the body and is not universal, as it is intended for heating specific products.

The task to which the invention is directed is to create a flexible inductor that allows uniformly heating the surface of cylindrical bodies of various diameters.

To solve the problem in a flexible inductor for heating cylindrical bodies, the induction wire, the ends of which are connected using a tightening device, is made in the form of a tape, the conductivity of which is less than, equal to or greater than the conductivity of the heated body, while the tape is equipped with a tension device, and the ends of the tape are designed to connect to a power source.

A tape made of a material whose electrical conductivity is less than, equal to or greater than the electrical conductivity of the heated body, allows you to change the ratio of energy transmitted to the part by induction and due to the thermal conductivity of the heated tape.

Heating of the tape should not lead to loss of mechanical properties, intensive oxidation or melting of the tape material.

An electrically insulating layer applied to at least one of the tape surfaces allows heating parts with electrically non-insulated surfaces, and also protects against electric shock and increases the safety of maintenance. If this layer is thermally conductive, the efficiency is increased. inductor and its cooling conditions are improved.

Applying a heat insulating layer to the outer surface of the tape increases the efficiency inductor by reducing heat loss to the environment.

The inductor ribbon may consist of several segments interconnected in series or in parallel. This allows heating regions of different widths of cylindrical bodies of various diameters.

The invention is illustrated in the drawing, where figure 1 shows the appearance of a flexible inductor wound on a cylindrical body; figure 2 is a transverse section of a tape according to claim 2; on figb is a cross section of a tape according to claim 4

A flexible inductor (figure 1) consists of an induction wire made in the form of a tape 1, the ends of which are connected using a tightening device 2 and are intended to be connected to a power source. The tape is equipped with a tension device 3 and wound on the surface of a cylindrical body 4.

An electrical insulating layer 5 may be applied to the tape 1 (Fig. 2), which may also be heat-conducting. This layer can be applied to both one and both surfaces of the tape. A heat-insulating layer 6 can also be applied either to the outer surface of the tape 1 itself (Fig. 3a), or to the electrically insulating layer 5 from the outer side of the tape 1 (Fig. 3b).

The inductor operates as follows. Before starting work, the tape 1 is tightly wound on the surface of the heated cylindrical body 4, the tension devices 3 are installed, and the ends of the tape 1 are connected mechanically with each other using a tightening device 2 (for example, using a clamp), the ends of the tape 1 are intended for electrical connection to a power source .

When applying high-frequency voltage from the power source, the cylindrical body 4 and the inductor are heated. As a result of heating, the tape of the inductor 1 lengthens, which leads to sagging, uneven heating of the body 4 due to the uneven gap between the inductor and the body 4 and overheating of the tape 1 in the place of sagging.

The use of tension devices 3 allows you to compensate for the temperature elongation of the tape 1 of the inductor and to provide a tight clip to the surface of the heated cylindrical body 4 during the entire heating cycle.

The tension device 3 can be made in the form of two parallel guides pressed against the surface of the body 4, into the gap between which the tape 1 is pulled using a spring mechanism.

As the insulating layer 5 can be used mica or polyimide film, as the most heat-resistant and heat-conducting materials.

The limitation on the maximum temperature of the heated body 4 is imposed by the heat resistance of the used electrical insulation, for example, when using a polyimide film, the maximum surface temperature of the body 4 under the inductor should not exceed 400 ° C.

For the insulating layer 6, you can use glass wool or silica wool.

To heat bodies of different diameters, the tape can be extended by connecting the segments to each other, for example, with clamps. If it is necessary to heat wide sections of cylindrical bodies, several turns can be wound in series or in parallel. In this case, it is advisable to install a tension device on each turn.

The use of this invention can improve the quality of heating, as well as increase the efficiency The flexible inductor is easy to manufacture and has a low cost.

Sources of information

1. Japan patent No. 2-87495 "HF induction heating coil", IPC 6 N 05 V 6/36, 23 K 13/01;

2. The certificate of the Russian Federation on PM No. 1591 "Flexible inductor", IPC 6 N 05 V 6/36, publ. 1/16/96, bull. PMPO No. 1-96 - prototype.

Claims (5)

1. A flexible inductor for heating cylindrical bodies, comprising an induction wire and a tightening device for the ends of the wire, characterized in that the induction wire is made in the form of a tape, the conductivity of which is less than, equal to or greater than the conductivity of the heated body, while the tape is equipped with a tension device designed to provide tight winding of the tape on the surface of the cylindrical body, and the ends of the tape are designed to be connected to a power source. 2. The flexible inductor according to claim 1, characterized in that at least one of the surfaces of the tape has an electrical insulating layer. 3. The flexible inductor according to claim 2, characterized in that the electrical insulating layer of the tape is thermally conductive. 4. The flexible inductor according to claim 1, or 2, or 3, characterized in that a heat insulating layer is applied to the outer surface of the tape. 5. A flexible inductor according to any one of claims 1 to 4, characterized in that the tape consists of several segments interconnected.

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