WO2023121127A1

WO2023121127A1 - Heater for vertical sintering furnace

Info

Publication number: WO2023121127A1
Application number: PCT/KR2022/020329
Authority: WO
Inventors: 한무호; 나상권
Original assignee: 포스코홀딩스 주식회사; 재단법인 포항산업과학연구원
Priority date: 2021-12-21
Filing date: 2022-12-14
Publication date: 2023-06-29
Also published as: KR20230094749A

Abstract

A heater for a vertical sintering furnace is provided. The heater according to the present invention comprises: a heater unit for generating a temperature at which graphitization raw materials are sinterable; an upper connection part which is connected to an upper part of the heater unit and to which an upper electrode for applying an electric current is installed; and a lower connection part which is connected to a lower part of the heater unit and to which a lower electrode for applying an electric current is installed.

Description

Heaters for vertical kilns

The present invention relates to a heater for a sintering furnace, and more particularly, to a heater for a vertical sintering furnace.

In general, artificial graphite is manufactured by heating an artificial graphite firing furnace to a very high temperature, for example, 2900° C. to 3000° C., using a heater, and retaining calcined coke, a raw material for graphitization, inside the heater for a certain period of time.

At this time, a heater made of graphite is used as a heating means for heating the graphitization raw material. In addition, the artificial graphite firing furnace is mainly used in a vertical type for continuous graphite production.

The heater of this vertical artificial graphite firing furnace is installed vertically in the center of the furnace surrounded by an insulating material.

When an integrated heater of the same material and size is installed in a firing furnace and energized, all heaters generate heat at the same temperature.

At this time, a huge amount of energy loss occurs in order to forcibly cool the generated heat.

The present invention is to provide a vertical sintering furnace heater capable of minimizing heat generated around the electrodes installed on and below the heater of the vertical graphite sintering furnace and generating the optimum temperature required for firing graphitized raw materials in the center of the heater. .

A heater of a vertical sintering furnace according to an embodiment of the present invention is a heater of a vertical sintering furnace installed in a vertical direction on the ground or an installation surface, and includes a heater unit for generating a temperature capable of sintering a graphitized raw material; It may include an upper connection part connected to an upper part of the heater part, at least a part of which protrudes to the outside of the heater, and an upper electrode for conducting electricity. In addition, the heater may include a lower connection part connected to a lower part of the heater part, at least a part of which protrudes to the outside of the heater, and in which a lower electrode for conducting electricity is installed.

The upper connection part and the lower connection part may be made of the same material as the heater part or made of a different material.

The heater may have a square tube shape or a circular tube shape.

When the heater is formed in the form of a square tube, passages having a square cross-section having the same size may be disposed on inner walls of the heater unit, the upper connection part, and the lower connection part.

A first upper expansion part extending in a width direction of the upper connection part from a straight line formed by an outer surface of the heater part may be provided on an outer surface of the upper connection part.

A length in the width direction of the outer surface of the first upper expansion unit may be set to be 1.5 to 5 times greater than the length of the outer surface of the heater unit in the width direction.

A first lower expansion part may be provided on an outer surface of the lower connection part extending in a width direction of the lower connection part from a straight line formed by an outer surface of the heater part.

A length in the width direction of the outer surface of the first lower expansion part may be set to be 1.5 to 5 times greater than the length of the outer surface of the heater part in the width direction.

When the heater is formed in a circular tube shape, passages having a circular cross-section having the same size may be disposed on inner circumferential surfaces of the heater unit, the upper connection part, and the lower connection part.

A second upper expansion part may be provided on an outer surface of the upper connection part extending in a radial direction of the upper connection part from a straight line formed by an outer surface of the heater part.

The size of the outer diameter of the second upper expansion unit may be set to be 1.5 to 5 times larger than the size of the outer diameter of the heater unit.

A second lower expansion part may be provided on an outer surface of the lower connection part extending in a radial direction of the lower connection part from a straight line formed by an outer surface of the heater part.

The outer diameter of the second lower expansion part may be set to be 1.5 to 5 times larger than the outer diameter of the heater part.

According to the embodiment of the present invention, it is possible to minimize the heat generated around the electrode units installed on and below the heater of the vertical graphite sintering furnace and generate the optimum temperature required for sintering the graphitization raw material in the central portion of the heater.

Accordingly, when the heater is energized, high efficiency can be achieved by appropriately designing and manufacturing the resistance values of the upper connection part and the lower connection part of the heater in the form of a square tube or a circular tube according to the situation of the vertical sintering furnace.

1 is a schematic configuration diagram showing a mounting state of a heater of a vertical sintering furnace according to an embodiment of the present invention.

2 is a schematic front view of a first embodiment of a heater for a vertical sintering furnace according to an embodiment of the present invention.

3 is a schematic perspective view of a first embodiment of a heater for a vertical sintering furnace according to an embodiment of the present invention.

4 is a schematic front view of a second embodiment of a heater for a vertical sintering furnace according to an embodiment of the present invention.

5 is a schematic perspective view of a second embodiment of a heater for a vertical sintering furnace according to an embodiment of the present invention.

6 shows a heater equivalent resistance structure and an electric current circuit diagram of a vertical sintering furnace according to the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described so that those skilled in the art can easily practice it. As can be easily understood by those skilled in the art to which the present invention pertains, the embodiments described below may be modified in various forms without departing from the concept and scope of the present invention. Where possible, identical or similar parts are indicated using the same reference numerals in the drawings.

The terminology used below is only for referring to specific embodiments and is not intended to limit the present invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite. As used herein, the meaning of "comprising" specifies specific characteristics, regions, integers, steps, operations, elements, and/or components, and other specific characteristics, regions, integers, steps, operations, elements, elements, and/or groups. does not exclude the presence or addition of

All terms including technical terms and scientific terms used below have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. The terms defined in the dictionary are additionally interpreted as having a meaning consistent with the related technical literature and the currently disclosed content, and are not interpreted in an ideal or very formal meaning unless defined.

1 is a schematic configuration diagram showing a mounting state of a heater of a vertical firing furnace according to an embodiment of the present invention, and FIG. 2 is a first heater of a vertical firing furnace (not shown) according to an embodiment of the present invention. It is a schematic configuration diagram of the embodiment.

Referring to FIGS. 1 to 3 , the heater 100 of the vertical firing furnace according to an embodiment of the present invention is installed in a vertical direction (Y direction in FIG. 1 ) on the ground or installation surface.

The heater 100 may include a heater unit 110 , an upper connection unit 120 , and a lower connection unit 140 .

The heater unit 110 is disposed at the central portion of the heater 100 in a vertical direction, and may generate a temperature capable of plasticizing the graphitization raw material.

In addition, the upper connection part 120 is connected to the upper part of the heater part 110, at least a part of it protrudes out of the heater 100, and the upper electrode 130 for conducting electricity may be installed on the upper part.

The lower connection part 140 is connected to the lower part of the heater part 110, at least a part of it protrudes out of the heater 100, and a lower electrode 150 for conducting electricity may be installed at the lower part.

An insulator 200 may be installed outside the heater 100 to insulate the heater 100 .

The upper connection part 120 and the lower connection part 140 may be made of the same material as the heater part 110 or made of a different material.

In addition, the upper connection part 120 and the lower connection part 140 have a specific resistance smaller than that of the material of the heater part 110 so that the amount of heat generated is smaller than that of the heater part 110 when electricity is applied to the heater 100. material can be made.

The heater part 110, the upper connection part 120, and the lower connection part 140 may be formed in a square tube shape or a circular tube shape.

First, as a first embodiment of the heater 100, a case in which the heater unit 110, the upper connection unit 120, and the lower connection unit 140 of the heater 100 have a square tube shape will be described as an example.

Inner walls of the heater unit 110, the upper connection unit 120, and the lower connection unit 140 may be provided with passages 101 having a rectangular cross section of the same size so that the graphitization raw material can be charged and heated.

On the outer surface of the upper connection part 120, a first upper part extending in a set length in the width direction (X direction in FIG. 2) of the upper connection part 120 from a straight line (X1-X1 line) formed by the outer surface of the heater part 110. The expansion part 121 may be integrally provided.

The length W12 in the width direction of the outer surface of the first upper extension part 121 is the width of the outer surface of the heater part 110 so that the resistance compared to the heater part 110 decreases by a set ratio when electricity is applied to the heater 100. It may be set in a range of 1.5 to 5 times the length W11 in the width direction (X direction in FIG. 2).

Here, the length (W12) in the width direction of the outer surface of the first upper extension portion 121 is the distance between the two opposing sides of the square tube of the first upper extension portion 121, particularly in the case of a rectangular tube shape. It can indicate the distance between the short sides.

In addition, on the outer surface of the lower connection part 140, a set length extends from a straight line (X1-X1 line) formed by the outer surface of the heater part 110 in the width direction (X direction in FIG. 2) of the lower connection part 140. 1 lower extension part 141 may be integrally provided.

The length W13 in the width direction of the outer surface of the first lower extension part 141 is the length of the outer surface of the heater part 110 so that the resistance compared to the heater part 110 is reduced by a set ratio when electricity is applied to the heater 100. It may be set in a range of 1.5 to 5 times the length W11 in the width direction (X direction in FIG. 2).

Here, the length (W13) in the width direction of the outer surface of the first lower extension portion 141 is the distance between the two opposing sides of the square tube of the first lower extension portion 141, particularly in the case of a rectangular tube shape, It can indicate the distance between the short sides.

Hereinafter, with reference to FIGS. 1 to 3 , the operation of the first embodiment of the vertical sintering furnace heater according to an embodiment of the present invention will be described.

In the following, the first embodiment of the heater 100 will be described as an example, but it can be applied to the second embodiment of the heater 100 as well.

The heater 100 is divided into three sections, that is, the upper connection part 120, the heater part 110, and the lower connection part 140, and the entire heater 100 is manufactured by connecting them.

Accordingly, the heat generated from the upper electrode 130 and the lower electrode 150 installed at the upper connection part 120 and the lower connection part 140 is minimized, and the heater part, which is the middle part of the heater 100 ( 110) can generate a sufficient temperature required for firing.

In addition, since at least some of the upper connection part 120 and the lower connection part 140 protrude outside the heater 100, they can be easily cooled at the part protruding outside the heater 100.

At this time, as the material of the upper connection part 120 and the lower connection part 140, a carbon material having a lower specific resistance compared to the heater part 110 located in the middle of the heater 100 is selected, and at the same time, the physical size is selected at the center of the heater 100. It is made larger than the heater unit 110.

That is, the lengths W12 and W13 in the width direction of the outer surfaces of the first upper extension part 121 and the first lower extension part 141 are defined as the width direction of the outer surface of the heater unit 110 (X direction in FIG. 2). ) is set in the range of 1.5 to 5 times the length (W11).

Accordingly, when electricity is applied to the heater 100, the equivalent resistance of the first upper extension part 121 and the first lower extension part 141 has a value smaller than that of the heater part 110 by a set ratio, and thus the amount of heat generated Since it is reduced by that much, heat loss due to cooling of the upper electrode 130 and the lower electrode 150 can be greatly reduced.

In addition, when the heater 100 is composed of three parts, the upper connection part 120, the heater part 110, and the lower connection part 140, during maintenance of the heater 100, only the damaged part is replaced to optimize the heater 100 ) can be managed.

The reason why the heater 100 is configured in this way can be explained from an electrical point of view as follows.

From an electrical point of view, the heater 100 can be viewed as a series connection structure of three resistors. 6 shows a heater equivalent resistance structure and an electric current circuit diagram of a vertical firing furnace according to the present invention.

That is, the heater 100 equivalent resistance structure is composed of the upper connection part 120 resistance, the heater part 110 resistance, and the lower connection part 140 resistance.

Phase control is performed using an SCR power element for controlling power supplied to the heater 100 .

Since the resistance of the graphite heater 100 is usually very low, on the order of several milliohms, power is supplied to the heater 100 after being converted into a low voltage and high current using a large current conversion transformer.

The power dissipated in a resistor is the square of the current through the resistor multiplied by the value of the resistor. Therefore, the power consumed by each resistor in the heater equivalent resistance structure can be expressed by the following equations (1-1), (1-2), and (1-3).

Upper connection power consumption = (load current) ² × upper connection resistance --- (1-1)

Heater power consumption = (load current) ² × heater resistance --- (1-2)

Lower connection power consumption = (load current) ² × lower connection resistance --- (1-3)

Since power consumed in each part of the heater 100 is connected in series, the load current is the same. The value that actually influences the power consumption of each part is the resistance value of each part.

Therefore, in order to improve the power efficiency of the sintering furnace, the resistance of the upper connection part 120 and the lower connection part 140 should be minimized compared to that of the heater part 110 .

In addition, the resistance of the graphite heater can be obtained by Equation 2 below.

R(Resistance)=ρ(Resistivity)×L(Length)/S(Cross Area) --- (2)

ρ (resistance) means the specific resistance of the graphite heater material. Unit is Ωm.

Resistance is proportional to resistivity and length, and inversely proportional to cross-sectional area. Therefore, when the specific resistance of the heater 100 is small or the cross-sectional area is large, the resistance is reduced.

Therefore, when the graphite material of the upper connection part 120 and the lower connection part 140 of the heater 100 is selected as a material with low resistivity and the length in the width direction is extended as shown in FIGS. 2 and 3, the heater 100 Compared to the heater part 110 in the central part, the resistance is reduced.

Hereinafter, as a second embodiment of the heater 100 with reference to FIGS. 4 and 5, the heater unit 110A, the upper connection unit 120A, and the lower connection unit 140A of the heater 100 have a circular tube shape. A case will be described as an example.

Here, A is added to the reference numeral of the square tube shape to distinguish it from the case where the heater part 110, the upper connection part 120, and the lower connection part 140 are in the form of a square tube.

On the inner circumferential surfaces of the heater part 110A, the upper connection part 120A, and the lower connection part 140A of the heater 100, a flow path 103 having a circular cross section having the same diameter is disposed so that the graphitization raw material can be charged and heated. It can be.

In addition, on the outer surface of the upper connection part 120A, a set length extends outward in the radial direction (X direction in FIG. 4) of the upper connection part 120A from the straight line (X2-X2 line) formed by the outer surface of the heater part 110A. The second upper expansion part 121A may be integrally provided.

The size of the outer diameter (D12) of the second upper expansion part (121A) is the size (D11) of the outer diameter of the heater part (110A) so that the resistance to the heater part (110A) is reduced by a set ratio when the heater 100 is energized. It may be set in the range of 1.5 times to 5 times the contrast.

In addition, on the outer surface of the lower connection part 140A, a set length extends from a straight line (X2-X2 line) formed by the outer surface of the heater part 110A to the outside in the radial direction (X direction in FIG. 4) of the lower connection part 140A. The second lower extension part 141A may be integrally provided.

The size of the outer diameter D13 of the second lower extension part 141A is the size of the outer diameter D11 of the heater part 110A so that the resistance to the heater part 110A decreases by a set ratio when the heater 100 is energized. It may be set in the range of 1.5 times to 5 times the contrast.

Hereinafter, with reference to FIGS. 4 and 5 , the operation of the second embodiment of the vertical sintering furnace heater according to an embodiment of the present invention will be described.

The outer diameter of the second upper extension 121A (D12) is set to be 1.5 to 5 times larger than the outer diameter of the heater 110A (D11), and the second lower extension 141A ) is set to be 1.5 times to 5 times larger than the size D11 of the outer diameter of the heater unit 110A.

Accordingly, when electricity is applied to the heater 100, the equivalent resistance of the second upper extension portion 121A and the second lower extension portion 141A has a value smaller than that of the heater portion 110A by a set ratio, and thus the amount of heat generated Since it is reduced by that much, heat loss due to cooling of the upper electrode 130 and the lower electrode 150 can be greatly reduced.

Although the present disclosure has been described through preferred embodiments as described above, the present invention is not limited thereto and various modifications and variations are possible without departing from the scope of the claims described below. Those in the field will easily understand.

[Description of code]

100: heater

110: heater part

120: upper connection

121: first upper extension

121A: second upper extension

130: lower connection

131: first lower extension

131A: second lower extension

Claims

As a heater of a vertical firing furnace installed in a vertical direction on the ground or installation surface,

A heater unit for generating a temperature capable of plasticizing the graphitization raw material;

An upper connection part connected to an upper part of the heater part, at least a part of which protrudes to the outside of the heater, and having an upper electrode for conducting electricity, and

A lower connection part connected to the lower part of the heater part, at least a part of which protrudes to the outside of the heater, and having a lower electrode for conducting electricity.

A heater of a vertical sintering furnace comprising a.
According to claim 1,

The upper connection part and the lower connection part are made of the same material as the heater part or made of a different material.
According to claim 1,

The heater is a heater of a vertical sintering furnace made of a square tube shape or a circular tube shape.
According to claim 3,

When the heater is formed in a square tube shape, a flow path having a square cross section having the same size is disposed on inner walls of the heater part, the upper connection part, and the lower connection part.
According to claim 4,

A heater of a vertical sintering furnace, wherein a first upper expansion portion extending in a width direction of the upper connection portion from a straight line formed by an outer surface of the heater portion is provided on an outer surface of the upper connection portion.
According to claim 5,

The length in the width direction of the outer surface of the first upper extension part is set to be in the range of 1.5 to 5 times the length of the outer surface of the heater part in the width direction.
According to claim 6,

A heater of a vertical sintering furnace, wherein a first lower expansion part extending in a width direction of the lower connection part from a straight line formed by an outer surface of the heater part is provided on an outer surface of the lower connection part.
According to claim 7,

The length in the width direction of the outer surface of the first lower expansion part is set to be 1.5 to 5 times the length of the outer surface of the heater part in the width direction.
According to claim 3,

When the heater is formed in a circular tube shape, a flow path having a circular cross section having the same size is disposed on inner circumferential surfaces of the heater part, the upper connection part, and the lower connection part.
According to claim 9,

A heater of a vertical sintering furnace, wherein a second upper expansion part extending in a radial direction of the upper connection part from a straight line formed by an outer surface of the heater part is provided on an outer surface of the upper connection part.
According to claim 10,

The size of the outer diameter of the second upper extension part is set to a range of 1.5 to 5 times the size of the outer diameter of the heater part.
According to claim 11,

A heater of a vertical sintering furnace, wherein a second lower extension part extending in a radial direction of the lower connection part from a straight line formed by an outer surface of the heater part is provided on an outer surface of the lower connection part.
According to claim 12,

The size of the outer diameter of the second lower expansion part is set to a range of 1.5 to 5 times the size of the outer diameter of the heater part.