CN211552483U - Electric heating element structure for high-temperature resistance hearth - Google Patents
Electric heating element structure for high-temperature resistance hearth Download PDFInfo
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- CN211552483U CN211552483U CN202020138123.2U CN202020138123U CN211552483U CN 211552483 U CN211552483 U CN 211552483U CN 202020138123 U CN202020138123 U CN 202020138123U CN 211552483 U CN211552483 U CN 211552483U
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Abstract
The utility model provides a high temperature resistance is electrothermal element structure for furnace, including electrothermal element, electrothermal element is a plurality of and the subregion is arranged, and every district is equipped with survey control mechanism, and electrothermal element locates the furnace top, and electrothermal element includes many heater strips, and survey control mechanism is used for measuring temperature and temperature regulation. The heating element is arranged at the top of the hearth, and the temperature of the heating furnace is uniform through partition arrangement and control. The electric heating element is hung on the furnace top through the hanger rod, the installation is convenient, and the electric heating element is prevented from being directly touched and conducting electricity after being deformed. Compared with a trolley type resistance furnace, the electric heating element is convenient to replace, when a fuse wire and a broken wire are caused, and the furnace is shut down, the whole replacement is not needed, and only the broken wire part is cut off for replacement or the wire is directly connected; convenient and simple maintenance and processing and strong universality. The diameter of the leading-out electrode of the electric heating element is 3 times larger than that of the electric heating element, the leading-out electrode material is consistent with the electric heating element material, and the temperature of the connection position of the leading-out electrode and the wiring can be reduced.
Description
Technical Field
The utility model belongs to the technical field of resistance heating furnace, concretely relates to high temperature resistance furnace uses electric heating element structure.
Background
The resistance furnace is an industrial furnace which heats a workpiece or a material by heating an electric heating element or a heating medium in the furnace by using current. The electric heating elements are resistance wires, carbon silicon rods and the like, and are divided into low-temperature, medium-temperature and high-temperature resistance furnaces according to different temperatures, wherein the low-temperature furnace is used at the working temperature of below 650 ℃, the medium-temperature furnace is used at 650-plus-1000 ℃ and the high-temperature furnace is used at above 1000 ℃. Heating is mainly by radiation in high and medium temperature furnaces. The furnace is heated in a low-temperature furnace in a convection heat transfer mode, the electric heating element is arranged in the air channel, and the air in the furnace is forced to circularly flow by the fan so as to strengthen the convection heat transfer.
The existing general resistance furnace is a trolley type resistance furnace, electric heating elements are arranged on two sides of a hearth and in grooves of the bottom of the furnace, and hot air circulates in the furnace by utilizing a circulating fan and a draft hood arranged outside a tempering fan, so that the processing temperature of a workpiece is uniform. The end wall and the furnace door of the large-scale trolley type resistance furnace are also provided with electric heating elements, and the furnace has the advantages of simple structure, good universality, low purchase cost and the like, and has the defects that the furnace is only suitable for heat treatment heating of small and medium-sized workpieces, the heat in the furnace is greatly dissipated when the furnace bottom is moved out, and the furnace temperature is quickly reduced. If the heating wire has the phenomena of fuse wire and broken wire, the treatment, the maintenance and the replacement are troublesome.
At present, the mode of fixing is carried out after adopting ceramic nail to insert the fibre folding piece of furnace lining to electric heating element's installation, leads to resistance furnace to carry out the during operation in 1100 ℃ of high temperature, and obvious crackle and outer wall overtemperature phenomenon can appear in the oven, and the performance is poor, and life is short, and electric heating element's installation adopts ceramic nail to fix mostly, because ceramic nail is heavier than the couple, its occupation space is big, causes electric heating element to warp the back directly to touch electrically conductive easily. Meanwhile, the thin slab is not uniformly heated by the electric heating element due to no reasonable partition.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a high temperature resistance is electrothermal element structure for furnace, the subregion is arranged and the subregion control, effectively solves the homogeneity problem of electrothermal element to the sheet bar heating.
Therefore, the utility model provides a technical scheme as follows:
the utility model provides a high temperature resistance is electrothermal element structure for furnace, includes electrothermal element, electrothermal element is a plurality of and subregion and arranges, and every district is equipped with survey control mechanism, electrothermal element locates the furnace top, electrothermal element includes many heater strips, survey control mechanism is used for measuring temperature and temperature regulation.
The electric heating elements in each zone are connected end to end through a plurality of heating wires to form a snake shape, the diameter of the extraction electrode of each electric heating element is larger than 3 times of the diameter of the electric heating element, and the extraction electrode material is the same as the electric heating element material.
The electric heating elements are arranged in a partition mode along the in-and-out direction of the furnace mouth, wherein the power of the electric heating elements close to the furnace mouth is larger than that of the electric heating elements arranged in other areas.
The electric heating element is hung below the furnace top.
The measuring and controlling mechanism comprises a thermocouple and a temperature controller, the thermocouple is electrically connected with the temperature controller, the temperature controller is electrically connected with the transformer, and the temperature controller is used for acquiring temperature data of the thermocouple and adjusting the voltage of the transformer after comparing the temperature data with a set value.
The power of the electric heating elements close to the furnace mouth is 15-20% higher than that of the electric heating elements arranged in other areas.
The furnace top comprises a rectangular pipe frame and a flame retardant coating, the flame retardant coating is fixed on a fixing plate of the rectangular pipe frame through hanger rods, the hanger rods are multiple, hanging structures are arranged at the lower ends of the hanger rods, and the electric heating elements are hung below the furnace top through the hanging structures.
The electric heating element is a tungsten wire or a molybdenum wire.
The utility model has the advantages that:
the utility model provides a this kind of high temperature resistance is electrothermal element structure for furnace, heating element arrange in the furnace top, arrange and control through the subregion, make heating furnace temperature even.
The electric heating element is hung on the furnace top through the hanger rod, the installation is convenient, and the electric heating element is prevented from being directly touched and conducting electricity after being deformed.
Compared with a trolley type resistance furnace, the electric heating element is convenient to replace, when the equipment is improperly used and fuses and wires are broken, the whole furnace is not required to be replaced after the furnace is shut down, and only the broken wire part is cut off and replaced or the wires are directly connected; convenient and simple maintenance and processing and strong universality.
The diameter of the leading-out electrode of the electric heating element is 3 times larger than that of the electric heating element, the leading-out electrode material is consistent with the electric heating element material, and the temperature of the connection position of the leading-out electrode and the wiring can be reduced.
In order to make the above and other objects of the present invention more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
FIG. 1 is a schematic view of the arrangement of the electric heating elements of the present invention;
FIG. 2 is a schematic view of an extraction electrode of an electrical heating element;
FIG. 3 is a schematic view of a boom construction;
fig. 4 is a schematic view of an end of a stove top.
In the figure:
description of reference numerals:
1. heating wires; 2. a boom; 3. a furnace roof; 4. a rectangular tube frame; 5. a nut; 6. a refractory layer; 7. leading out an electrode; 8. a hanging structure; 9. a pull rod.
Detailed Description
The following description is provided for illustrative embodiments of the present invention, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the disclosure herein.
In the present invention, the upper, lower, left, and right in the drawings are regarded as the upper, lower, left, and right of the electric heating element structure for the high-temperature resistance furnace described in this specification.
The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, which, however, may be embodied in many different forms and are not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art. The terminology used in the exemplary embodiments presented in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.
Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
Example 1:
this embodiment provides a high temperature resistance is electrothermal element structure for furnace, including electrothermal element, electrothermal element arranges for a plurality of and subregion, and every district is equipped with survey control mechanism, electrothermal element locates the furnace top, electrothermal element includes many heater strips 1, survey control mechanism is used for measuring temperature and temperature regulation.
The utility model provides a this kind of high temperature resistance is electrothermal element structure for furnace, heating element arrange in the furnace top, arrange and control through the subregion, make heating furnace temperature even.
Example 2:
this embodiment provides a high temperature resistance is electrothermal element structure for furnace, including electrothermal element, electrothermal element arranges for a plurality of and subregion, and every district is equipped with survey control mechanism, electrothermal element locates the furnace top, electrothermal element includes many heater strips 1, survey control mechanism is used for measuring temperature and temperature regulation.
The electric heating elements of each zone are connected end to end through a plurality of heating wires 1 to form a snake shape, the diameter of a leading-out electrode 7 of each electric heating element is larger than 3 times of the diameter of the electric heating element, and the material of the leading-out electrode 7 is the same as that of the electric heating element. As shown in fig. 1 and 2.
The diameter of the leading-out electrode 7 of the electric heating element is 3 times larger than that of the electric heating element, the material of the leading-out electrode 7 is consistent with that of the electric heating element, and the temperature of the connection position of the leading-out electrode 7 and a wiring can be reduced.
Example 3:
this embodiment provides a high temperature resistance is electrothermal element structure for furnace, including electrothermal element, electrothermal element arranges for a plurality of and subregion, and every district is equipped with survey control mechanism, electrothermal element locates the furnace top, electrothermal element includes many heater strips 1, survey control mechanism is used for measuring temperature and temperature regulation.
The electric heating elements are arranged in a partition mode along the in-and-out direction of the furnace mouth, wherein the power of the electric heating elements close to the furnace mouth is larger than that of the electric heating elements arranged in other areas.
In the area close to the furnace mouth, the surface power of the unit area needs to be improved at the position close to the furnace mouth because the heat loss in the process of opening the furnace door is too large. In this embodiment, the power of the electric heating elements near the furnace mouth is 15-20% greater than that of the electric heating elements arranged in other zones.
Example 4:
this embodiment provides a high temperature resistance is electrothermal element structure for furnace, including electrothermal element, electrothermal element arranges for a plurality of and subregion, and every district is equipped with survey control mechanism, electrothermal element locates the furnace top, electrothermal element includes many heater strips 1, survey control mechanism is used for measuring temperature and temperature regulation.
The electric heating element is hung below the furnace top 3.
The electric heating element is hung on the furnace top 3 through the hanger rod 2, the installation is convenient, and the electric heating element is prevented from being directly touched and conducting electricity after being deformed.
Compared with a trolley type resistance furnace, the electric heating element is convenient to replace, when the equipment is improperly used and fuses and wires are broken, the whole furnace is not required to be replaced after the furnace is shut down, and only the broken wire part is cut off and replaced or the wires are directly connected; convenient and simple maintenance and processing and strong universality.
Example 5:
this embodiment provides a high temperature resistance is electrothermal element structure for furnace, including electrothermal element, electrothermal element arranges for a plurality of and subregion, and every district is equipped with survey control mechanism, electrothermal element locates the furnace top, electrothermal element includes many heater strips 1, survey control mechanism is used for measuring temperature and temperature regulation.
The measuring and controlling mechanism comprises a thermocouple and a temperature controller, the thermocouple is electrically connected with the temperature controller, the temperature controller is electrically connected with the transformer, and the temperature controller is used for acquiring temperature data of the thermocouple and adjusting the voltage of the transformer after comparing the temperature data with a set value.
In the present embodiment, as shown in fig. 1, the electric heating elements are arranged in three zones. The temperature control system adopts a three-channel temperature controller (model 2604) to control the temperature in the furnace, carries out temperature acquisition through three couples, sends acquired data into respective channels and respectively controls the temperature of three areas of the furnace. When the temperature of a certain area is low or high, the temperature controller controls the current and the voltage of the transformer through an internally arranged PID adjusting controller, so that the furnace temperature reaches a set temperature value.
Example 6:
this embodiment provides a high temperature resistance is electrothermal element structure for furnace, including electrothermal element, electrothermal element arranges for a plurality of and subregion, and every district is equipped with survey control mechanism, electrothermal element locates the furnace top, electrothermal element includes many heater strips 1, survey control mechanism is used for measuring temperature and temperature regulation.
The electric heating element is hung below the furnace top 3.
The furnace top 3 comprises a rectangular tube frame 4 and a flame retardant coating 6, the flame retardant coating 6 is fixed on a fixing plate of the rectangular tube frame 4 through a plurality of suspenders 2, a hanging structure 8 is arranged at the lower end of each suspender 2, and the electric heating elements are hung below the furnace top 3 through the hanging structures 8.
As shown in FIG. 3, the hanger rod 2 comprises three parts, wherein the upper part is made of stainless steel, the middle part is made of molybdenum, the lower part is made of tungsten, and the bottom end of the lower part is provided with a hanging structure 8. The upper part, the middle part and the lower part are connected through screw threads.
The hanger rod 2 is mainly used for connecting and fixing the refractory fiber board and fixing the hanging heating wire 1 through the hanging structure 8. The suspender 2 is arranged in the middle of the multilayer fireproof layer 6 in a penetrating way.
As shown in fig. 4, the end of the stove top 3 is fixed by a nut 5 after passing through the multi-layer refractory 6 by a tie rod 9. The pull rod 9 comprises an upper half section and a lower half section, the upper half section and the lower half section are connected through threads, the upper half section is made of stainless steel, and the lower half section is made of molybdenum. The function of the tie rod 9 is to connect and fix the refractory layer 6. The lower half section is made of high-temperature molybdenum and is fireproof.
Example 7:
this embodiment provides a high temperature resistance is electrothermal element structure for furnace, including electrothermal element, electrothermal element arranges for a plurality of and subregion, and every district is equipped with survey control mechanism, electrothermal element locates the furnace top, electrothermal element includes many heater strips 1, survey control mechanism is used for measuring temperature and temperature regulation.
The electric heating element is a tungsten wire or a molybdenum wire.
In this embodiment, the heating furnace is a hydrogen resistance heating furnace, and the electric heating element material is tungsten or molybdenum, and since the temperature of the heating furnace is 1650 ℃, the temperature of the electric heating element should be 1700 ℃ to 1800 ℃. The melting point of molybdenum is 2610 deg.C, molybdenum has the characteristics of high strength, high hardness and excellent mechanical property, and can still retain high strength and high hardness at high temperature, so that molybdenum wire is selected as electric heating element.
Example 8:
the embodiment provides an arrangement method of an electric heating element structure for a high-temperature resistance hearth, which comprises the following steps:
step 1) determining a material of an electric heating element according to the highest service temperature of a high-temperature resistance furnace;
step 2) determining the installation power P of the electric heating element according to the volume of the heating resistance furnace, then determining the installation power of each zone, and determining the number of the heating wires 1 of each zone according to the installation power, the voltage and the resistance of each heating wire 1;
in the formula, P is the power of the heating furnace, KW; k is a comprehensive correction coefficient which increases along with the increase of the furnace temperature and takes the value of 100-; v is the volume of the heating resistance furnace;
and 3) connecting the plurality of heating wires 1 of each zone end to form a snake shape, arranging and hanging the snake shape on the top of the hearth in a subarea manner along the furnace mouth inlet and outlet direction, and arranging the measuring and controlling mechanisms in subareas to complete the arrangement of the electric heating element structure.
The volume of the heating resistor furnace is the sum of the volume of the furnace chamber and the volume of the furnace mouth connecting neck, and the volume of the furnace mouth connecting neck is the volume between the furnace mouth and the furnace chamber.
In this embodiment, the heating furnace is a hydrogen resistance heating furnace (furnace chamber size is 4350 × 3280 × 610), and the electric heating element material is tungsten or molybdenum, and the temperature of the electric heating element should be 1700 ℃ to 1800 ℃ because the heating furnace temperature is 1650 ℃. The melting point of molybdenum is 2610 deg.C, molybdenum has the characteristics of high strength, high hardness and excellent mechanical property, and can still retain high strength and high hardness at high temperature, so that molybdenum wire is selected as electric heating element.
As shown in fig. 1, the power of the furnace is distributed over three zones. Determining the installation power P of the electric heating element according to the volume of the heating resistance furnace, then determining the installation power of each zone, and determining the number of the heating wires 1 of each zone according to the installation power, voltage and resistance of a single heating wire 1;
in the formula, P is the power of the heating furnace, KW; k is a comprehensive correction coefficient which increases along with the increase of the furnace temperature and takes the value of 100-; v is the volume of the heating resistance furnace.
Wherein K is related to the furnace temperature, the type of the heat shield, the heating time and the operation form. K is 150-200 at 1400 ℃, 200-250 at 1600 ℃, and 250-300 at 1800 ℃. Because the hearth has large volume, large amount of charging materials and large heat loss and heat accumulation of the furnace, the K value is 300.
The relationship between the volume of the heating resistance furnace, the installation power and the power per the surface area in the furnace chamber is shown in table 1.
TABLE 1 relationship between heating resistance furnace volume, installation power and unit hearth internal surface area power
According to the size of a hearth, the length of each zone of three zones of heating wires 1 is preliminarily listed, molybdenum wires with the diameter phi of 3 are selected, and the resistance value of a single molybdenum wire is calculated:
in the formula: r0Resistance value (omega) of single filament; rho is the resistivity rho of molybdenum at 1800 ═ 0.556 omega mm2(ii)/m; s is the sectional area mm of the heating wire 12(ii) a L is the length of the single heating wire 1.
Selection of voltage: the working voltage of the electric heating element should not be too high, and the evaporation of the electric heating element is increased because the insulation resistance of the refractory material is rapidly reduced at high temperature. The surface conductivity of the insulator is increased, and arc discharge is easily generated between electrodes, thereby increasing the danger in work. The voltage is too high, and the electric heating element is thin and long, so that the installation is difficult and the service life is shortened; when the voltage is too low, the electrothermal elements are thick and short, the element consumption is increased, the cost is increased, and the voltage is controlled below 100V generally.
And preliminarily determining the power distribution of three zones according to the calculated heating furnace power, and calculating the current I and the resistivity R of each zone.
In the formula: i is current, A; p is power per zone, W; r is the resistance value per region (omega).
Determining the number of elements per zone
Calculating the actual surface power (W/cm) of the element of the single-zone heating wire 12)
In the formula: wbActual unit surface power of the element (W/cm)2) (ii) a P is the power (W) of a single zone; n is the number of each electric heating element; d is the diameter (cm) of a single filament; l is the length (cm) of the single zone filament; wy is the unit surface power (W/cm) allowed by the element2)。
And calculating the power and the number of the electric heating elements in each area according to the formula until the numerical values meet the table 2.
TABLE 2 allowable specific surface Power W of electric heating elementsy(W/cm2)
It will be understood by those skilled in the art that the foregoing embodiments are specific examples of the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in its practical application.
Claims (8)
1. The utility model provides an electric heating element structure for high temperature resistance furnace, includes electric heating element, its characterized in that: the electric heating element is a plurality of and the subregion is arranged, and every district is equipped with surveys control mechanism, electric heating element locates the furnace top, electric heating element includes many heater strips (1), it is used for measuring temperature and temperature regulation to survey control mechanism.
2. The electric heating element structure for the high-temperature resistance furnace according to claim 1, characterized in that: the electric heating elements in each area are connected end to end through a plurality of heating wires (1) to form a snake shape, the diameter of a leading-out electrode (7) of each electric heating element is larger than 3 times of the diameter of the electric heating element, and the material of the leading-out electrode (7) is the same as that of the electric heating element.
3. The electric heating element structure for the high-temperature resistance furnace according to claim 1, characterized in that: the electric heating elements are arranged in a partition mode along the in-and-out direction of the furnace mouth, wherein the power of the electric heating elements close to the furnace mouth is larger than that of the electric heating elements arranged in other areas.
4. The electric heating element structure for the high-temperature resistance furnace according to claim 1, characterized in that: the electric heating element is hung below the furnace top (3).
5. The electric heating element structure for the high-temperature resistance furnace according to claim 1, characterized in that: the measuring and controlling mechanism comprises a thermocouple and a temperature controller, the thermocouple is electrically connected with the temperature controller, the temperature controller is electrically connected with the transformer, and the temperature controller is used for acquiring temperature data of the thermocouple and adjusting the voltage of the transformer after comparing the temperature data with a set value.
6. The electric heating element structure for the high-temperature resistance furnace according to claim 1, characterized in that: the power of the electric heating elements close to the furnace mouth is 15-20% higher than that of the electric heating elements arranged in other areas.
7. An electric heating element structure for a high-temperature resistance furnace according to claim 4, characterized in that: the furnace top (3) comprises a rectangular tube frame (4) and a fire-resistant layer (6), the fire-resistant layer (6) is fixed on a fixing plate of the rectangular tube frame (4) through a plurality of hanging rods (2), hanging structures (8) are arranged at the lower ends of the hanging rods (2), and the electric heating elements are hung below the furnace top (3) through the hanging structures (8).
8. The electric heating element structure for the high-temperature resistance furnace according to claim 1, characterized in that: the electric heating element is a tungsten wire or a molybdenum wire.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202020138123.2U CN211552483U (en) | 2020-01-21 | 2020-01-21 | Electric heating element structure for high-temperature resistance hearth |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202020138123.2U CN211552483U (en) | 2020-01-21 | 2020-01-21 | Electric heating element structure for high-temperature resistance hearth |
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