WO2019235474A1 - Immersion heater for non-ferrous molten metal - Google Patents

Abstract

The present invention relates to an immersion heater for non-ferrous molten metal and provides an immersion heater the service life of which can be extended even when the temperature of heating elements of SiC heaters contained therein is increased. The immersion heater (1) has a single or multiple vertical SiC heaters (2) disposed in a straight cylindrical ceramic protective tube (3) and is filled with nitrogen. The immersion heater is characterized by being provided with a vent pipe (4) connected to the nitrogen in the protective tube and an oxygen scavenging layer (4-1) made of Ti, Nb, or Si metal and connected to the vent pipe, whereby outside air is deoxidized and replenished with nitrogen in order to keep the balance.

Description

Immersion heater for non-ferrous metal melt

The present invention relates to a non-ferrous metal molten immersion heater that is charged into a non-ferrous metal melt such as aluminum or zinc and heats the molten metal. The present invention relates to an immersion heater.

As shown in FIGS. 5 and 6, a non-ferrous metal melt holding furnace used to heat and hold a molten non-ferrous metal such as aluminum or zinc is a vertical furnace equipped with a heating element in a protective tube made of a ceramic refractory. A mold or horizontal immersion heater is provided. Such an immersion heater has a ceramic tube having high insulation properties in order to protect a heating element heated by energization from reaction with the molten metal and to insulate it from the molten metal. Since the ceramic tube is immersed in a high-temperature molten metal, it is manufactured from a material having high mechanical strength, excellent thermal shock resistance and wear resistance, and high thermal conductivity. For this purpose, a silicon nitride sintered body (Si ₃ N ₄ ), a boron nitride sintered body (BN), or the like is often used.

On the other hand, as the heating element housed in the ceramic tube, heaters of various shapes such as a rod heater and a spiral heater are known. As the heater material, materials such as SiC, nichrome wire, and molybdenum disilicide are used. Recently, there has been a demand for a heating element that has a large calorific value, a stable operation, and a long life corresponding to a large molten metal holding furnace. In this respect, it can withstand a heating element surface temperature of 1400 to 1600 ° C. An SiC heating element having a large heat generation amount, that is, equivalent to 5 to 10 times that of a nichrome heating element has been adopted.

Initially, the SiC heating element is also a recrystallized SiC having a high porosity of 20 to 25%, and the maximum heating temperature is limited to about 1400 ° C. at the heating element surface temperature in terms of the lifetime due to oxidation of SiC. Adopting reaction sintered type SiC with a rate of 10% or less, heating element surface temperature can be used up to 1600 ° C, and the specific resistance is as low as 0.02 Ωcm. Thus, there has been disclosed a prior art that can be used with an existing power source and can be used with a three-phase power source in a high-temperature furnace at 1400 to 1600 ° C.

Japanese Patent Laid-Open No. 2001-257056 ([0002-0004], [FIG. 1], [FIG. 4])

The prior art is superior in that the surface temperature of the heating element of the SiC heating element is raised, but in the case of a non-ferrous metal melt immersion heater, this SiC heating element is installed in a ceramic tube as a protective tube. Usually, the inside of the tube is filled with air. In this state, when the SiC heating element is energized to generate heat, SiC undergoes a reaction of SiC + 2O ₂ = SiO ₂ + CO ₂ with oxygen in the air, and initially, this reaction proceeds rapidly, but is generated. When the surface is covered with the SiO ₂ film, the oxidation rate gradually becomes slower and the resistance increase due to oxidation becomes slow. However, when the amount of SiO ₂ gradually increases with long-term use, the resistance starts to increase from the initial 1.8 to 2 times, and increases rapidly when the resistance becomes 3 to 4 times. It is said that the lifetime of the SiC heating element is exhausted due to the increase in resistance and the variation in temperature coefficient due to this increase in resistance. In particular, in the case of a spiral heating element, there has been a problem that a breakage accident of a heating part of a spiral suddenly occurs.

The present invention solves these problems, and prevents the oxidation of the SiC heating element of the immersion heater during heat generation, thereby extending the life of the heating element and increasing the temperature upper limit of the heating element. Can extend the life of SiC heating elements and improve / maintain performance. Overall, it is possible to improve the operation rate of molten metal holding furnaces and melting furnaces that melt non-ferrous metal ingots in molten metal, and thus maintain the quality of molten metal. The purpose is to reduce maintenance costs.

In order to achieve the above object, an SiC immersion heater for heating a non-ferrous metal melt according to claim 1 of the present invention is an SiC immersion heater used in a non-ferrous metal melt holding furnace. An immersion heater in which one or a plurality of vertical SiC heaters are arranged, and a protective tube is filled with nitrogen, a ventilation pipe communicating with outside air is provided inside the protective pipe, and the ventilation pipe is By connecting to a deoxygenation layer made of Ti, Nb, or Si metal, nitrogen that has been deoxygenated from the outside air is replenished so as to supplement nitrogen inside the protective tube.

Conventionally, the inside of a protective tube made of an insulating ceramic containing a vertical heater is filled with air communicating with the outside air, so that the SiC heating element is oxidized at about 800 ° C. or higher, whereas the SiC of the present invention The immersion heater has a protective tube filled with nitrogen and prevents the SiC heating element from being oxidized at 800 ° C. or higher. Further, when the SiC heating element rises or falls, the gas in the protective tube expands and contracts to enter and exit the gas, but in the present invention, the gas can enter and exit through the vent pipe communicating with the outside air, and the outside air In the case of inhaling from oxygen, oxygen passes through the Ti, Nb or Si deoxidation layer and is absorbed and removed by Ti, Nb or Si metal, and only nitrogen is replenished.

By adopting the configuration of claim 1 of the present invention, the SiC heating element can be prevented from being oxidized from SiC to SiO ₂ at 800 ° C. or higher by maintaining the atmosphere in the protective tube only with nitrogen, so that the characteristics of the SiC heating element are maintained. In addition, the temperature of the heating element can be increased, and the heating capability of the heating element can be improved and the life can be extended. 

Further, the SiC immersion heater for heating non-ferrous metal melt according to claim 2 is the SiC immersion heater for heating non-ferrous metal melt according to claim 1, wherein the SiC heater has a double spiral heating element. To do.

With this configuration, since the SiC heater has a double spiral long current flow path, even if SiC has a low resistance, a large Joule heat can be generated, and a SiC immersion heater having a large heat output can be obtained. SiO ₂ of the heater contributes to the improvement and lifetime extension of the thermal power can be avoided.

The SiC immersion heater for heating non-ferrous metal melt according to claim 3 is the SiC immersion heater for heating non-ferrous metal melt according to claim 1 or 2, wherein the upper limit of the heat generation temperature of the heating element of the SiC heater is 1300 ° C. It is characterized by being.

When the heat generation temperature of the SiC heating element of the SiC heater becomes 1400 ° C. or higher, SiC reacts with N ₂ gas in the protective tube to generate a nitride of Si ₃ N ₄ , thereby impairing the life of the SiC heater. In order to prevent this, it is possible to extend the life while maintaining the performance of the SiC heater by adopting a configuration where the upper limit of the use temperature is 1300 ° C.

Further, the SiC immersion heater for heating non-ferrous metal melt according to claim 4 is the SiC immersion heater for heating non-ferrous metal melt according to claim 1, 2 or 3, wherein the Ti or Nb or Si deoxidation layer is granular, It is characterized by being filled with Ti, Nb, or Si metal that is either powdery, fibrous, or a mixture thereof.

With this configuration, it is possible to improve the air permeability of the deoxidation layer and increase the total surface area that contributes to the deoxidation reaction of the metal to increase the deoxygenation capacity, thereby removing the oxygen content into the protective tube. Nitrogen gas can be supplied reliably.

Further, the SiC immersion heater for heating non-ferrous metal melt according to claim 5 is the SiC immersion heater for heating non-ferrous metal melt according to any one of claims 1 to 4, wherein the Ti or Nb or Si deoxidation layer is It is characterized in that it is provided in a hemispherical portion at the tip of the protective tube and in a room partitioned by a partition wall which supports the tip of the heating element of the SiC heater and has a plurality of air holes at the corners.

By adopting this configuration, the capacity of the deoxygenation layer can be sufficiently secured, so that nitrogen can be replenished from outside air into the protective tube without any bias, and the temperature of the deoxygenation layer is set to the temperature of the heater heating element. It is possible to make the same degree, and the deoxygenation reaction from the outside air can be surely advanced.

Further, the SiC immersion heater for heating non-ferrous metal melt according to claim 6 is the SiC immersion heater for heating non-ferrous metal melt according to claim 5, wherein the use temperature of the Ti deoxidation layer is in a temperature range of 800 to 1300 ° C. It is characterized by being.

When the use temperature of the Ti deoxygenation layer is 800 ° C. or lower, deoxidation by Ti metal is insufficient, and when it is 1400 ° C. or higher, Ti metal selectively reacts with nitrogen rather than oxygen to lower the deoxygenation ability. . Therefore, by taking a temperature range that avoids this problem, that is, the temperature of the SiC heating element as a heat source is set to an upper limit of 1300 ° C. or less so that the use temperature of the Ti deoxidation layer is in a temperature range of 800 to 1300 ° C. By adjusting to at least 800 degrees or more, the Ti deoxygenation layer can maintain an appropriate deoxygenation capacity.

The SiC immersion heater for heating non-ferrous metal melt according to claim 7 is the SiC immersion heater for heating non-ferrous metal melt according to claim 5, wherein the Nb deoxidation layer is used at a temperature range of 200 to 1000 ° C. It is characterized by being.

When the use temperature of the Nb deoxygenation layer is 200 ° C. or less, the deoxidation by the Nb metal is insufficient, and when it is 1000 ° C. or more, the Nb metal selectively reacts with nitrogen rather than oxygen to lower the deoxygenation ability. . Therefore, by taking a temperature range that avoids this problem, that is, the temperature of the SiC heating element as a heat source is set to an upper limit of 1000 ° C. or less so that the use temperature of the Nb deoxygenation layer becomes a temperature range of 200 to 1000 ° C. By adjusting to at least 200 degrees or more, the Nb deoxygenation layer can maintain an appropriate deoxygenation capacity. Therefore, it is necessary to deoxygenate the gas passing through the vent pipe when the temperature of the SiC heating element is in the temperature range of 200 to 1000 ° C.

The SiC immersion heater for heating non-ferrous metal melt according to claim 8 is the SiC immersion heater for heating non-ferrous metal melt according to claim 5, wherein the use temperature of the Si deoxidation layer is in a temperature range of 800 to 1300 ° C. It is characterized by being.

When the use temperature of the Si deoxygenation layer is 800 ° C. or lower, the deoxidation by Si metal is insufficient, and when it is 1400 ° C. or higher, the Si metal softens and melts and the deoxygenation ability is lowered. Therefore, by taking a temperature range that avoids this problem, that is, the temperature of the SiC heating element as a heat source is set to an upper limit of 1300 ° C. or less so that the use temperature of the Si deoxidation layer is in a temperature range of 800 to 1300 ° C. By adjusting to at least 800 degrees or more, the Si deoxygenation layer can maintain an appropriate deoxygenation capability.

According to the SiC immersion heater for heating a non-ferrous metal melt according to the first to eighth aspects of the present invention, when the SiC heating element of the immersion heater generates heat, oxidation by the air in the protective tube can be prevented to prevent deterioration of the heating element. As a result, the temperature upper limit of the heating element can be increased, and the life of the heating element can be extended. As a result, the service life of the SiC heating element can be extended and the performance can be improved and maintained. As a whole, the operation rate of the molten metal holding furnace and molten metal melting furnace can be maintained and improved, and the quality of the molten metal in the molten metal holding furnace and molten metal furnace can be maintained In addition, the replacement of the immersion heater is reduced, the damage due to cooling and heating of the molten metal holding furnace and the melting furnace in the molten metal is reduced, and the maintenance cost can be reduced. In addition, the SiC immersion heater for heating non-ferrous metal melt according to the present invention can be widely applied as a stable heat source for melting non-ferrous metal ingots and chips, so that the application range in the non-ferrous metal field can be expanded. it can.

FIG. 1 is a schematic perspective sectional view of a non-ferrous metal melt immersion heater according to an embodiment for carrying out the present invention. FIG. 2 is a schematic plan view of an immersion heater for molten nonferrous metal according to an embodiment for carrying out the present invention. FIG. 3 is a schematic side cross-sectional view taken along line AA in FIG. 4 is a schematic side cross-sectional view taken along the line BB in FIG. FIG. 5 shows another non-ferrous metal immersion heater according to an embodiment for carrying out the present invention, in which (a) is a schematic plan view and (b) is a schematic view taken along line AA in (a). (C) is a schematic side cross-sectional view taken along the line BB in (a). FIG. 6 is an example of a layout diagram of the vertical immersion heater in the non-ferrous metal melt holding furnace. FIG. 7 is an example of a layout diagram of the horizontal immersion heater in the non-ferrous metal melt holding furnace.

An SiC immersion heater 1 for heating a non-ferrous metal melt according to the present invention (hereinafter referred to as SiC immersion heater 1) will be described with reference to FIGS. The SiC immersion heater 1 has three SiC heater bodies 2 equally spaced apart from the inner wall surface of the protective tube 3 in the longitudinal direction of the protective tube 3 in the protective tube 3 of a straight cylindrical insulating ceramic, and has a central angle of about 120. Arranged in degrees. Insulating ceramics must be manufactured from a material with high mechanical strength, excellent thermal shock resistance and wear resistance, and high thermal conductivity because it is immersed in a high-temperature molten metal to transfer heat. Therefore, a silicon nitride sintered body (Si ₃ N ₄ ) or a boron nitride sintered body (BN) can be used.

The SiC heater body 2 has a cylindrical shape, and includes a non-heating element 2-2 having no resistance connected to an electric terminal portion 2-3 to which a power source is connected and a heating element 2-1 having a high resistance. -2 is vertically divided into two conductive paths for supplying electricity to the heating element 2-1. On the other hand, the heating element 2-1 is a heating element having a spiral groove, as shown in FIG. 1. The heating element 2-1 extends from the place where it is connected to the non-heating element 2-2 to the hollow cylindrical body made of SiC. Along the direction, two grooves having a spiral shape in the portion up to the other end side are cut and connected at the tip. The heating element 2-1 has a shape in which two long spiral current paths are connected even if the main body is SiC having low resistance, so that resistance can be secured and large Joule heat can be generated.

The SiC heater main body 2 has a tip end portion at the heater tip support portion of the partition wall 7 in the hemisphere portion 3-1 at the tip end of the protective tube 3 and a root portion at the heater root support portion 6 at the root portion of the protection tube 3. Fixed. The SiC heater main body 2 is appropriately positioned in the protective tube 3 by these tip and base support portions, and the heat generation energy of the three SiC heater main bodies 2 is transferred to the cylindrical portion 3-2 of the protective tube 3. In contrast, heat is transferred appropriately by radiant heat transfer.

In addition, in order to control the surface temperature of the heating element 2-1 of the SiC heater body 2, the thermocouple tube 5 is installed in parallel with the three SiC heater bodies 2 and at substantially the center position of the three heaters. The tip 5-1 of the thermocouple to be measured is preferably installed at the approximate center of the heating element 2-1 of the SiC heater body 2, and this measured temperature indicates the surface temperature of the heating element 2-1. The temperature signal is guided to a temperature setting adjusting device (not shown) via a thermocouple compensating lead 5-2, and the current is adjusted from the outside to the electrical terminal section 2-3 to obtain a surface temperature (eg, 1200 ° C.). Applied.

In the SiC immersion heater 1 of the present invention, the protective tube 3 is filled with nitrogen, and if the heating element 2-1 of the SiC heater body 2 is conventional air, the SiC is oxidized at about 800 ° C. or higher. Thus, it is possible to prevent the change to SiO ₂ and maintain the SiC state. Further, when the nitrogen in the protective tube 3 expands or contracts as the SiC heating element 2-1 increases or decreases in temperature, the nitrogen in the protective tube 3 flows through the vent 4-2, the deoxygenated layer 4-1, the vent tube. In the present invention, only nitrogen can enter and exit through the vent pipe 4 communicating with the outside air. That is, when inhaling from outside air using a Ti metal deoxidation layer, it passes through the Ti metal deoxidation layer 4-1 heated to a temperature range of 800 to 1300 ° C. via the vent pipe 4. Sometimes oxygen reacts with Ti and is removed by the reaction Ti + O ₂ = TiO ₂ and only nitrogen is inhaled. Further, when inhaling from the outside air using the Nb metal deoxidation layer, it passes through the Nb metal deoxidation layer 4-1 heated to a temperature range of 200 to 1000 ° C. via the vent pipe 4. Sometimes oxygen reacts with Nb and is removed by the reaction 2Nb + O ₂ = 2NbO, and only nitrogen is inhaled. Further, when inhaling from the outside air using a Si metal deoxidation layer, it passes through the Si metal deoxidation layer 4-1 heated to a temperature range of 800 to 1000 ° C. via the vent pipe 4. Sometimes oxygen reacts with Si and is removed by the reaction Si + O ₂ = SiO ₂ and only nitrogen is inhaled. Incidentally, a plug portion 2-4 is formed at the base of the SiC heater main body 2 of the present invention, whereby the SiC heater main body 2 and the protective tube 3 of the SiC immersion heater 1 can be separated from the outside air only by the vent pipe 4. It will be connected.

When the SiC immersion heater 1 according to the present invention has an output of 34 kW and is composed of three SiC heaters 2, the protective tube 3 has an outer diameter of 170 mm and a length of 900 mm. The diameter is 40 mm and the length is 900 mm. The Ti metal forming the oxygen scavenging layer 4-1 is made of sponge Ti, which can be processed into granular, powdery or fibrous forms and has a filling weight of about 600 to 700 gr. The outer diameter of the vent pipe 4 is about 20 mm. The thermocouple is normal and can be used through an alumina protective tube 4 × 6 mm.

An SiC immersion heater 1 according to another embodiment of the present invention will be described with reference to FIG. There is a feature in the arrangement and configuration of the vent pipe 4 that fills the protective pipe 3 of the SiC immersion heater 1 with nitrogen. The SiC heater main body 2 is composed of three pieces, and three vent pipes 4 are arranged between the inside of each SiC heater main body between the inside of the protective tube 3 and the outside air. Each vent pipe 4 is opposed to the heating element 2-1 of the SiC heater main body 2, and has a deoxidation layer 4-1 filled with a deoxidation material, and two vents for holding the deoxygenation layer 4-1. Consists of plug 4-3. The deoxidation layer 4-1 can be made of Ti metal, Nb metal, or Si metal that has a deoxidation effect in the form of particles, powder, or fibers. Further, in order to hold the deoxidation layer 4-1, porous ceramic vent plugs 4-3 are provided at two places above and below. Since the deoxidation layer 4-1 is provided in each of the three vent pipes 4 and is sandwiched between the two vent plugs 4-3, the deoxidation layer is composed of Ti, Nb, or Si metal. There are few restrictions on material capacity. Since the gas flowing into the protective tube 3 always passes through the three vent tubes 4, the flowing outside air is contained in the deoxidation layer 4-1, which is built in and heated to a high temperature by the radiation of the SiC heater body 2. Since it is deoxidized and flows in when it passes, the inside of the protective tube 3 can maintain a state without oxygen, so that the performance of the SiC heater main body 2 can be sufficiently exhibited and the life of the heater can be extended.

The SiC immersion heater 1 of the present invention is mainly composed of a SiC heater main body 2 and a protective tube 3, and is usually in the vertical direction (FIG. 6) or the horizontal direction (FIG. 6) in the molten metal M of the molten metal holding furnace 10 shown in FIGS. 7) soaked and installed. As for the heat output of the SiC immersion heater 1, the heat generated by the SiC heater body 2 is transferred to the molten metal M via the protective tube 3, and the molten metal M is heated or held at a constant temperature by the thermal energy. In the SiC immersion heater 1, the thermal energy of the temperature of the SiC heater body 2 (usually 900 to 1300 ° C.) is transmitted to the inner wall of the protective tube 3 by heat transfer mainly composed of radiation, and the cylindrical portion of the protective tube 3 is mainly used. Although the inner wall of 3-2 is heated, since the protective tube 3 is immersed in the molten metal, the temperature of the protective tube 3 is estimated to be slightly higher than the molten metal temperature (for example, 650 to 720 ° C. in the case of molten aluminum). .

Therefore, the higher the surface temperature of the SiC heater body 2, the higher the heat energy for heating the inner wall of the protective tube 3, and the temperature of the molten metal M in contact with the protective tube 3 is increased. However, if the surface temperature of the SiC heater body 2 is in the air, the oxidation of SiC to SiO2 occurs, so the limit is 1000 ° C., and the performance of the SiC heater body 2 is limited. In contrast, the SiC heating element 2-1 of the immersion heater 1 of the present invention can prevent the oxidation of SiC to SiO _{2 in} nitrogen, so that the surface temperature can be up to 1300 ° C. However, when the surface temperature of the SiC heating element 2-1 is 1400 ° C. or higher, SiC reacts with nitrogen to become Si ₃ N _{4 and the} SiC deteriorates. Therefore, in the present invention, by causing the SiC heater body 2 to generate heat in a nitrogen atmosphere, if the surface temperature of the SiC heating element 2-1 is in the air, 1000 ° C. is the maximum from the point of oxidation of SiC. On the other hand, if it is in nitrogen, the surface temperature can be increased to 1300 ° C and the amount of heat transferred to the molten metal M can be increased, and the life of the SiC heating element 2-1 can be extended by preventing the oxidation of SiC. I made it.

The SiC immersion heater 1 of the present invention is at room temperature before being energized and heated, and the protective tube 3 is filled with only nitrogen gas. When the SiC immersion heater 1 is energized and heated, the nitrogen gas expands and escapes to the outside air through the vent pipe 4. When the temperature level of the SiC heater main body 2 (in the range of 1000 to 1300 ° C.) is reached, the nitrogen gas in the protective tube 3 is also in a stable volume state with little heat change. Thereafter, when it is necessary to lower the temperature of the SiC immersion heater 1 when the molten metal holding furnace 10 is stopped, the nitrogen gas in the protective tube 3 contracts and the outside air enters through the vent tube 4. The oxygen in the outside air is combined with Ti, Nb, or Si metal by the Ti, Nb, or Si metal deoxidation layer 4-1 connected to the ventilation pipe 4 to form respective oxides, and the oxygen content is removed from the outside air. Only the protective tube 3 is replenished. The deoxidation of Ti and Si metal starts at 700 ° C, but the upper limit is preferably 1300 ° C. The upper limit is set to 1300 ° C. When the temperature exceeds 1400 ° C., Ti metal reacts with nitrogen in the outside air to form a nitride, resulting in insufficient deoxidation, and in the case of Si metal, 1400 ° C. Exceeding may cause softening and melting. On the other hand, the deoxidation of Nb metal starts at 200 ° C., but when it exceeds 1000 ° C., it reacts with nitrogen, so that the deoxidizing power may be reduced.

Therefore, in order to replenish nitrogen from the outside air, it is preferable that the temperature of the tip portion 5-1 of the thermocouple 5 indirectly indicating the temperature of the Ti or Si deoxidation layer 4-1 is 700 to 1300 ° C. . On the other hand, in the case of the Nb deoxygenation layer 4-1, it is preferably performed at 200 to 1000 ° C.

The present invention can be applied not only to holding furnaces for molten non-ferrous metals such as aluminum and zinc and melting furnaces in molten metal but also to the field of melting treatment of non-ferrous metal lumps and chips.

1: SiC immersion heater 2: SiC heater body 2-1: Heating element 2-2: Non-heating element 2-3: Electrical terminal section 2-4: Embolization section 3: Protective tube 3-1: Hemisphere section 3-2: Cylindrical part
4: Vent pipe 4-1: Deoxygenated layer 4-2: Vent hole 4-3: Vent plug 5: Thermocouple 5-1: Thermocouple tip 5-2: Thermocouple compensating conductor 6: Heater base support
7: Bulkhead (heater tip support)
10: Molten metal holding furnace M: Molten metal

Claims (8)

In SiC immersion heaters used in non-ferrous metal melting furnaces or melting furnaces, one or more vertical SiC heaters are arranged in a straight cylindrical insulating ceramic protective tube, and the protective tube is filled with nitrogen The immersion heater is provided with a ventilation pipe communicating with the outside air inside the protection pipe, and connecting the ventilation pipe to a deoxidation layer made of Ti, Nb, or Si metal, thereby removing nitrogen from the outside air. A SiC immersion heater for heating non-ferrous metal melt, which is replenished so as to supplement nitrogen inside the protective tube. The SiC immersion heater for heating a non-ferrous metal melt according to claim 1, wherein the SiC heater has a double spiral heating element. 3. The SiC immersion heater for heating a non-ferrous metal melt according to claim 1, wherein an upper limit of a use heat generation temperature of the heating element of the SiC heater is 1300 ° C. 3. The Ti, Nb, or Si deoxidation layer is configured to be filled with Ti, Nb, or Si metal that is granular, powdery, fibrous, or a mixture thereof. Or SiC immersion heater for non-ferrous metal molten metal heating of 2 or 3. A chamber in which the Ti, Nb, or Si deoxygenation layer is partitioned by a partition wall that supports the tip of the heating element of the SiC heater and has a plurality of air holes in the corners in the hemispherical portion of the protective tube. The SiC immersion heater for heating a non-ferrous metal melt according to any one of claims 1 to 4, wherein the SiC immersion heater is provided inside. 6. The SiC immersion heater for heating non-ferrous metal melt according to claim 5, wherein the use temperature of the Ti deoxidation layer is in a temperature range of 800 to 1300 ° C. 6. The SiC immersion heater for heating non-ferrous metal melt according to claim 5, wherein the Nb deoxygenation layer is used in a temperature range of 200 to 1000 ° C. 6. The SiC immersion heater for heating non-ferrous metal melt according to claim 5, wherein the use temperature of the Si deoxidation layer is in a temperature range of 800 to 1300 ° C.

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