RU45884U1 - ELECTRIC HEATER - Google Patents

Abstract

The utility model relates to techniques for electric heating, in particular, to devices for heating an insulating liquid, for example, transformer oil during installation, repair and maintenance of power oil-filled electrical apparatus.

The objective of the utility model is to increase reliability and achieve high-quality heating of transformer oil with different electric heater powers.

The electric heater comprises a housing with a cover and a bottom, inlet and outlet pipes and with tubular heating elements located inside, which have insulating sleeves and contact leads and pipes of the heating elements discharged through the cover or bottom of the housing.

According to a utility model, the upper and lower distributors for the heated medium are installed in the casing and above the cover and (or) under the bottom of the casing there is a conductive section of the heating elements sectioned into groups in the form of mica-plastic heating elements, including metal strips located arched between the protruding through the lid and (or) the bottom of the casing with tubes of heating elements, at the ends of which insulating sleeves are installed, and the output wires of the contact leads are connected to strips installed on the rib in the insulating plates nachki, which are rigidly fixed to brackets mounted vertically on the lid and (or) on the bottom of the housing, the insulating sleeves have the appearance of a mushroom, the leg of which is placed in the tubes of the heating elements, and the mushroom cap closes the end of the tube.

The strips are copper busbars that are electrically connected to a panel of a power cabinet (not shown).

Tubes of heating elements are located inside the housing from the side of the lid and (or) the bottom and are directed opposite to each other.

To exclude accidents and improve safety, the copper busbars and protruding tubes of the heating elements attached to the lid and (or) the bottom of the housing are closed with a metal protective casing.

For reliability of the conductive part of the heating elements, slots are made on the surfaces of the insulating strips for the installation of copper bars.

To preserve the sealing unit in the heating elements, the sleeves in the pipes of the heating elements are made of ceramic material, and the middle part of the legs of the ceramic bushings has a pin hole, and two holes are made vertically in the sleeve for passing the wires of the contact leads. Coaxial to the hole in the leg of the ceramic bushings on the walls of the tubes of the heating elements made holes for holding the pin. Moreover, the inlet pipe for oil is located in the lower part of the housing, and the outlet pipe is installed in the upper part of the housing. To maintain the temperature of the heated oil, the housing is located in a casing with thermal insulation in the form of mineral piercing material.

Description

The utility model relates to techniques for electric heating, in particular, to devices for heating an insulating liquid, for example, transformer oil during installation, repair and maintenance of power oil-filled electrical apparatus.

Famous fluid electric heater according to copyright certificate No. 1760651, class. H 05 V 3 \ 20, publ. 09/07/1992, contains a cylindrical body with a cover and a bottom, which are hermetically connected to the body through a flange connection.

The lid and bottom are fastened with a body - quick-detachable and is carried out using hinged bolts. The cover has a nozzle for exiting and connecting to the heating medium line, and the bottom has a nozzle for introducing fluid into the electric heater body under pressure from the pump.

In the case, sections with corrugated heating elements are sequentially mounted on removable bases.

The bases are attached to the stops with bolts, and the stops are welded to the body.

Corrugated heating elements are made of electrical steel tape and are connected to the current source via busbars through bushing insulators installed in the housing wall.

The turns of the heating tape are laid spirally or zigzag in the grooves formed by the fiberglass planks, which are installed in the slots of the frame base of the section.

The fluid flow is in contact with the heating elements, and the mirror arrangement of the corrugations of the next section relative to the corrugations of the previous one provides mixing of the layers of the heated fluid.

A disadvantage of the known device is the uneven heating of the fluid due to the presence of dead zones in the housing, since there is no circulation of the heated medium, the flow of which washes only one side of the heating tape.

Known electric heater for heating liquids according to the patent of Ukraine No. 33911, class. H 05 B 3 \ 28, publ. 02.17.2003 (or see Belavin Yu.A., Evstigneev MA, Chernyavsky AN "Tubular electric heaters and installations with their use" M., Energoatomizdat, 1989, p. 6, fig. .46, p. 20, fig. 13, p. 23, fig. 146) contains a protective sheath made of silver, in which a resistive heating element is placed through which electric current passes.

An insulating material is located between the protective shell and the heating element, and an anti-corrosion coating, for example, of chromium or nickel, is placed on top of the protective shell.

The heat flux passing through the insulating material, the shell of silver, the anti-corrosion coating is transferred to the liquid.

A disadvantage of the known electric heater is the continuous contact of the silver shell with a liquid having an antimicrobial effect, which makes it possible to use the design only in food engineering.

Known electric heater according to the declaration patent of Ukraine No. 35491 A, class. H 05 B 3 \ 28, publ. 03/15/2001 is designed for processing and heating transformer oil, vertically arranged tubular heating elements are installed inside the metal case of the electric heater, fixed in the holes of the sieve, which is installed in the lower part of the case. The open end of each tube of heating elements made with a thread is brought out through the housing cover.

Brackets are attached to the opened open ends of the pipes of the heating elements, with the help of which the open parts of the heating spirals with contact leads are held. The protective casing covers the output ends of the pipes of the heating elements with the open part of the heating spirals.

The other end of each pipe of the heating elements is plugged and discharged through a sieve closer to the bottom of the housing or pipes of the heating elements are removed through the bottom of the housing. An open heating coil of heating elements is installed in a ceramic insulator, which is located at the end of each pipe of heating elements.

In the lower part of the casing, a pipe is made for the transformer oil to enter the electric heater, and the oil pipe is installed in a protective casing and is connected through the cover to the casing.

This design of the electric heater is taken as a prototype.

The disadvantages of the prototype are as follows:

- explosion and fire safety are not fully ensured, which reduces the reliability of the electric heater during operation, since failure of heating elements occurs quite often, which requires the replacement of heating elements by soldering their leads and removing the metal fastening on the brackets due to burned heating elements

- formation of “dead zones” in the housing is not ruled out due to uneven heating of the oil or there is a danger of overheating and foaming of the oil, and it is not possible to adjust the power of the electric heater due to damage to the heating elements.

The utility model is based on the task of developing an electric heater of transformer oil, which provides high-quality heating of oil to temperatures of + 50 ° С- + 80 ° С- + 100 ° С using mica-plastic heating elements that are interconnected and determine the power of the electric heater, while the area does not change heating surface and ensures reliability in operation.

The solution to this problem is provided by an electric heater containing a housing with a cover and a bottom, inlet and outlet pipes and with tubular heating elements located inside, which are led out through the cover or bottom of the housing and have insulating sleeves and contact leads, due to the fact that the upper and the lower distributors for the heated medium and the heating elements are mica-plastic heating elements, and above the cover and (or) under the bottom of the housing there is a sectioned group of conductors The main part of the heating elements, including metal strips located in an arcuate manner between the heating elements tubes protruding through the cover and (or) the bottom of the housing, at the ends of which are insulating sleeves, and the output wires of the contact leads are connected to strips mounted on the rib in the insulating strips, which are rigidly fixed to brackets mounted vertically on the lid and (or) on the bottom of the case, and the insulating sleeves are in the form of a mushroom, the leg of which is placed in the tubes, and the mushroom cap closes the end of the tube.

The strips are copper busbars whose ends are electrically connected through an insulating plate to a panel of a power cabinet (not shown).

The upper and lower valves are in the form of a metal ring with holes through which the tubes of the heating elements pass. Also, the holes in the distributors serve to pass the heated medium, for example, oil.

To improve heating, the oil flow located inside the tube housing of the heating elements from the side of the lid and (or) the bottom is directed opposite to each other.

To distribute the heating temperature and for the symmetry of the oil flow in the housing, the lower metal ring of the distributor is installed above the inlet pipe, and the upper metal ring of the distributor is installed below the output pipe.

To eliminate accidents and improve safety, the fixed copper busbars and protruding tubes of the heating elements on the lid and (or) under the bottom of the case are closed with a metal protective casing.

For reliability of the conductive part of the heating elements, slots are made on the surfaces of the insulating strips for the installation of copper bars.

To preserve the sealing unit in the heating elements, the sleeves in the pipes of the heating elements are made of ceramic material and the middle part of the legs of the ceramic bushings has a pin hole, and two holes are made vertically in the sleeve for passage of the contact leads.

Coaxially with the hole in the leg of the ceramic bushings, holes for passing and holding the pin are made on the walls of the tubes of the heating elements.

Moreover, the lower inlet pipe is located in the lower part of the housing, and the outlet pipe is installed in the upper part of the housing opposite to the lower pipe.

To maintain the temperature of the heated oil, the housing is located in a casing with thermal insulation in the form of mineral piercing material.

The technical result achieved using the utility model:

- the design has been improved, mica-plastic heating elements installed in hollow tubes are used in the oil heater, thereby eliminating heat dissipation, and the mica-plastic heating elements can be removed from the hollow tube and replaced with a new one;

- the energy consumption of the electric heater is reduced and the specific power of the heating elements is reduced by connecting the terminals of the heating elements in series to copper strips arranged in an arcuate and partitioned into groups, while the sectioned strip groups are installed above or below the end surface of the lid and (or) the bottom of the heater case using insulating strips and the ends of the strips are electrically connected through an insulating plate and a conductive element to the panel of the power cabinet;

- increased durability and reliability in operation due to the exclusion of direct contact of mica-plastic heating elements with oil without the risk of thermal decomposition, since ceramic bushings in the form of a mushroom are installed at the ends of the heating elements coming out of the electric heater body, and the wires of the contact leads pass through two holes made vertically inside bushings, which allows you to connect the heating elements with a certain power of the electric heater and connect them to the copper strips, partitioned into groups and exclude contact with m scrapped,

- oil corruption is reduced and uniform heating of oil is achieved in the electric heater case due to the possible location of the heating elements tubes in the upper and lower parts of the housing, while the heating elements tubes located inside the housing are directed opposite to each other.

The inventive electric heater for heating transformer oil is illustrated by the following description and drawings, where:

Figure 1 is a General view of the electric heater, inside the case of which the tubes of the heating elements are located opposite each other,

Figure 2 is a top view of figure 1 with the metal protective cover removed,

Figure 3 - sectioned into groups of the heating part of the electric heater,

Figure 4. - tube mica plastic TENA with a ceramic sleeve in the tube TENA,

Figure 5 - fastening of insulating strips on the surfaces of the cover and (or) the bottom of the body with copper busbars that are installed in the slots of the strips.

A utility model, an electric heater for heating transformer oil contains a metal cylindrical body 1 with a cover 2 and a bottom 3, which may have an elliptical surface (see figure 1).

In the housing 1, vertically arranged tubular heating elements are installed in the form of mica-plastic heating elements 4, the tubes of which exit from the cover 2 of the housing, i.e. protrude above the surface of the cover 2 and (or) the tubes 4 exit through the bottom 3 of the housing, while the tubes of the heating elements 4 located inside the housing 1 from the side of the cover 2 and (or) from the bottom of the 3 are directed opposite to each other (see figure 1 4).

At the protruding ends of the tubes of the heating elements 4, insulating (ceramic) bushings 5 and contact leads 6 are installed (see figure 1, figure 4).

Ceramic bushings 5 of the heating elements 4 have the appearance of a mushroom, the leg 7 of which is installed in the heating element 4 tube, and the mushroom cap 8 closes the end of the tube 4 (see Fig. 1, Fig. 3, Fig. 4).

At the same time, the middle part of the leg 7 of the sleeve 5 has an opening 9 for installing the pin 10, and two holes 11 are made vertically inside the sleeve 5, through which the wires of the contact terminals 6 pass, which, in turn, exit through the cap 8 of the fungus to the outside of the heater tube 4 (see figure 4).

Coaxial to the hole 9 in the leg 7 of the sleeve 5 on the walls of the tubes of the heating elements 4 holes 12 are made to hold the installed pin 10 in the leg 7 (see figure 1, figure 4.).

In the tubes of the heating elements 4, mica layers 13 are laid, between which there is a non-chrome spiral (not shown), the output of which is connected to the contact leads 6 (see figure 4).

Above the lid 2 and (or) under the bottom 3 of the housing 1, the conductive part of the heating elements 4 is partitioned into groups, including metal strips (copper bars) 14 arranged in an arc (see figure 1, figure 2, figure 3).

Between the ends of the tubes of the heating elements 4 with ceramic bushings 5 protruding from the housing 1, copper busbars 14 are installed, while the wires of the contact leads 6 exit through the holes 11 from the cap 8 of the bushings and are connected to the busbars 14 by rigidly fastening the twisted end 15 of the wire 6 to the busbars 14 (see Fig. 1, Fig. 4, Fig. 5).

Copper bars 14 above the surface of the cover 2 and (or) under the bottom 3 of the housing 1 are mounted on the rib and are held in insulating strips 16, which are rigidly fixed with a screw bolt 17 to metal brackets 18 mounted vertically on the surface of the cover 2 and (or) on bottom surface 3.

Moreover, on the surfaces of the insulating strips 16 are made parallel to the slots 19 for reliable installation of copper bars 14 (see figure 1, figure 3, figure 5).

Inside the housing 1, the tubes of the heating elements from the side of the cover 2 and (or) from the bottom 3 are directed opposite to each other and their other ends are plugged (see figure 1).

The copper bars 14 fixed to the surface of the cover 2 and (or) to the bottom 3 of the housing 1 and the ends of the tubes of the heating elements 4 protruding from the housing 1

closed by a metal casing 20 to protect against accidental damage, and the casing 20 has windows 21 for the ends from A1 to Z2 of the copper bars 14 to exit (see figure 1, figure 3).

The ends A1 to Z2 of the copper busbars 14 are electrically connected through the conductive elements 22 to a panel of a power cabinet (not shown), the element 22 being placed in a metal casing 20.

In the lower part of the housing 1, a pipe 23 for oil inlet is installed, and a pipe 24 for the oil outlet is located in the upper part of the housing 1 opposite the inlet lower pipe 23 (see Fig. 1, Fig. 3)

In the housing 1 of the electric heater, the upper and lower distributors 25 and 26 are installed, which have the form of a metal ring with holes 27 through which the tubes of the heating elements 4 and holes 27 are used to pass the heated oil.

The lower metal ring of the distributor 26 is installed above the inlet pipe 23, while the oil flow passes through the holes 27 and is directed tangentially in the housing 1, and the upper metal ring of the distributor 25 is installed below the upper output pipe 24 (see figure 1, figure 2)

The housing 1 of the electric heater is located in a casing 28 with thermal insulation in the form of mineral piercing material 29. Corner scarves 30 are installed to the housing 1, which are designed for rigid fastening to another metal structure (not shown) (see Fig. 1, Fig. 2).

During operation of the electric heater, transformer oil enters the housing 1 through the inlet 23 and the oil flows tangentially to the upper part of the housing 1. The oil is heated uniformly with the help of mica plastic heating elements 4 to an average temperature of + 50 ° С- + 80 ° С and, exiting through the pipe 24, it is supplied to the installation (not shown) for further oil treatment, and the heated oil is taken from the electric heater and enters the installation using a pump (not shown).

The inventive electric heater allows to reduce labor costs and to achieve high-quality heating of transformer oil in a housing with different power of the electric heater.

Claims (15)

1. An electric heater comprising a housing with a cover and a bottom, inlet and outlet nozzles and with tubular heating elements located inside, which are led out through the cover or bottom of the housing and have insulating sleeves and contact leads, characterized in that the upper and lower distributors are installed in the housing of the heated medium and heating elements are mica-plastic TENIs, and above the cover and / or under the bottom of the housing there is a conductive section of the TENOV sectioned into groups, including metal electrical strips located in an arcuate manner between the heating elements tubes protruding through the cover and / or the bottom of the housing, at the ends of which insulating sleeves are installed, and the output wires of the contact leads are connected to strips mounted on a rib in insulating strips, which are rigidly fixed to brackets mounted vertically on the cover and / or on the bottom of the housing, the insulating sleeves having the appearance of a mushroom, the leg of which is placed in the tubes, and the mushroom cap closes the end of the tube. 2. The electric heater according to claim 1, characterized in that the upper and lower distributors are in the form of a metal ring with holes through which the tubes of the heating elements pass. 3. The electric heater according to claim 2, characterized in that the openings in the distributors serve to pass the heated medium. 4. The electric heater according to claim 1, characterized in that the strip is connected to the contact terminals of the heating elements. 5. The electric heater according to claim 1, characterized in that the stripes are copper bars. 6. The electric heater according to claim 1, characterized in that the heaters tubes located inside the housing from the side of the lid and / or bottom are directed opposite to each other. 7. The electric heater according to claim 1, characterized in that the strips and protruding ends of the heating elements above the lid and / or under the bottom of the housing are closed with a metal protective casing. 8. The electric heater according to claim 1, characterized in that on the surfaces of the insulating strips are made parallel to the slots for installing copper busbars. 9. The electric heater according to claim 1, characterized in that the bushings in the tubes of the heating elements are made of ceramic material. 10. The heater according to claim 1, characterized in that the middle part of the legs of the bushings has a hole for the pin, and two holes are made vertically in the sleeve for the passage of the contact leads. 11. The electric heater of claim 10, characterized in that the hole for the pin in the leg of the bushings is located coaxially with the holes that are made in the walls of the tubes of the heating elements.  12. The electric heater according to claim 1, characterized in that the inlet pipe is located in the lower part of the housing, and the outlet pipe is installed in the upper part of the housing opposite to the lower pipe. 13. The electric heater according to claim 1, characterized in that the lower distributor is installed above the inlet pipe. 14. The electric heater according to claim 1, characterized in that the upper distributor is installed below the outlet pipe. 15. The electric heater according to claim 1, characterized in that the housing is located in a casing with thermal insulation in the form of mineral piercing material.