JP6372079B2 - Heating and melting apparatus, heating and melting system, and tapping controller - Google Patents

Description

  The present invention relates to a hot water control technique in a heating and melting apparatus that melts silicon, ceramics such as alumina and zirconia.

  As the above-described heating and melting apparatus, for example, an apparatus that melts a melting raw material by induction heating as in the apparatus described in Patent Document 1 is known. Ceramics such as silicon, alumina, and zirconia are non-conductive materials that do not conduct electricity at room temperature and are conductive only at high temperatures. It does not occur and cannot be induction heated. Therefore, in Patent Document 1, carbon as a conductor is disposed between a non-conductive quartz crucible and an induction heating coil, and the carbon is first induction-heated. Then, the silicon in the crucible is indirectly heated by radiant heat or heat conduction from the carbon whose temperature has risen, and after the silicon has risen in temperature and becomes conductive, the silicon is directly heated by induction.

  Here, in the apparatus of Patent Document 1, a hot water outlet is provided at the bottom of the crucible, and the melt is discharged from the hot water outlet by dissolving silicon that closes the hot water outlet. At that time, it is desirable to be able to predict the hot water start time for preparation of hot water, etc., but Patent Document 1 does not particularly mention such a method.

  On the other hand, Patent Document 2 discloses a method for predicting the start time of hot water in a melting apparatus. However, this melting apparatus is a cold crucible melting apparatus which is a kind of induction heating melting apparatus, and uses a metal which is a conductor as a melting raw material. In this cold crucible melting device, a crucible is formed by arranging a plurality of conductive segments spaced apart from each other in the circumferential direction. And the metal raw material in a crucible is melt | dissolved by induction heating by making a magnetic flux osmose | permeate in a crucible from the clearance gap between electroconductive segments, cooling a crucible.

  Since the crucible is cooled in the cold crucible melting apparatus, when the dissolved liquid comes into contact with the inner wall surface of the crucible, the dissolved liquid is cooled and solidified to form a skull. As a result, the hot water outlet provided at the bottom of the crucible is closed by the skull. In the cold crucible melting apparatus of Patent Document 2, an induction heating coil is provided around the outlet, and the hot water is discharged by melting the skull closing the outlet with this coil. The start time of the hot spring is predicted as follows.

  In this cold crucible melting apparatus, when the skull is melted, the electrical resistivity increases and the inductance of the coil increases. The power source for supplying an alternating current to the coil is constituted by a resonance circuit that operates so as to always have a resonance frequency in accordance with a change in the inductance of the coil. Can be understood as Therefore, by detecting the resonance frequency of the power source, the situation where the skull is thin is grasped, and the start time of hot water is predicted.

JP 2010-70404 A JP 2001-355969 A

  As described above, in the heating and melting apparatus as in Patent Document 1, it is conceivable to apply the method for predicting the hot water start time described in Patent Document 2 in order to meet the demand for predicting the hot water start time. However, the prediction method of Patent Document 2 has the following problems. Since the skull solidified on the inner wall surface of the crucible is a conductive metal, the magnetic flux from the coil is greatly attenuated by the skull, and the penetration depth of the magnetic flux becomes shallow. In order to detect the inductance change of the coil, the interface between the skull and the solution needs to reach the penetration depth of the magnetic flux, but if the penetration depth of the magnetic flux is shallow, the skull must be in a very thin state. Inductance change cannot be detected. In other words, in this cold crucible melting apparatus, the start time of the hot water could not be predicted unless it is just before the start of the hot water where the skull becomes very thin. Moreover, the start time of the hot water varied even with the same dissolved material.

  Therefore, in the present invention, in a heating and melting apparatus in which silicon or ceramic that is a non-conductor at normal temperature and becomes conductive at a temperature higher than normal temperature is used as a melting material, and a hot water outlet is formed at the bottom of the crucible, The aim is to be able to predict the start time early.

  In order to solve the above-described problems, a heating and melting apparatus according to the present invention is a heating and melting apparatus using silicon or ceramic that is a non-conductor at room temperature and has conductivity at a temperature higher than room temperature as a melting material. A melting part for melting the melting raw material; a crucible that is located below the melting part and has a hot water outlet having a hot water outlet formed at the bottom, and made of a material that transmits magnetic flux; and the melting A heating means for heating the melting raw material housed in the crucible and housed in the crucible, a coil disposed around the tapping part and receiving an alternating current, and detecting a change in inductance of the coil Detecting means.

  In the heating and melting apparatus according to the present invention, since the heating means is arranged around the melting part of the crucible, the melting raw material in the melting part is first melted, and then the melting raw material in the tapping part below the melting part. Dissolution proceeds from top to bottom. That is, the dissolution proceeds in such a form that the interface between the dissolution liquid and the undissolved dissolution raw material gradually moves downward. In this heating and melting apparatus, the crucible is formed of a material that transmits magnetic flux, and non-conductive silicon or ceramic is used as a melting material at room temperature. For this reason, the magnetic flux from the coil arrange | positioned around the tapping part permeates to the deep inside of the crucible without being attenuated by a crucible or a melting raw material at room temperature. When the magnetic flux reaches the vicinity of the interface between the dissolved solution and the undissolved dissolved raw material, the undissolved dissolved raw material whose electric resistivity has decreased due to the temperature rising due to heat transfer from the dissolved solution, Eddy currents are generated in the solution having a low electrical resistivity, and the magnetic flux is attenuated. For this reason, as melting progresses and the interface moves downward, the number of flux linkages passing through the coil decreases, and as a result, the inductance of the coil decreases. And the movement state of an interface can be grasped | ascertained by detecting the change of the inductance of a coil with a detection means. At this time, as described above, in the present heating and melting apparatus, since the magnetic flux from the coil arranged around the tapping part penetrates deeply to the interface, the change in inductance due to the movement of the interface can be detected from an early stage. The hot spring start time can be predicted early.

  In this heating and melting apparatus, it is preferable that the coil has a function of inductively heating the melting raw material with a high-frequency current. In this way, by performing induction heating with a coil arranged around the hot water discharge portion, it is possible to promote the dissolution of silicon in the hot water discharge portion.

  At this time, it is more preferable that a heating element formed of carbon felt or porous carbon is provided between the hot water outlet and the coil. Since the heating element made of carbon felt or porous carbon is a conductor, it melts by radiant heat or heat conduction from the heating element that is induction-heated by the coil while the melting raw material in the tapping part is non-conductive at room temperature. The raw material can be efficiently heated. Moreover, since carbon felt and porous carbon have many voids, the heating element also functions as a heat insulating material for the hot water outlet, and has an effect of keeping the solution warm and preventing solidification.

  In addition, it is preferable to further include a control means for controlling the hot water start timing based on the detection signal from the detection means. By providing such a control means, it becomes possible to start the hot water at an appropriate time according to the progress of melting.

  Further, in the heating and melting system including any one of the heating and melting apparatuses described above, the raw material charging unit is configured to input the raw material charging unit based on a change in inductance of the coil detected by the raw material charging unit and the detecting unit. It is preferable to provide raw material charging control means for controlling the timing of charging the molten raw material into the crucible from the means.

  According to such a heating and melting system, the raw material charging control means controls the timing of charging the molten raw material from the raw material charging means, so that the melting raw material is charged into the crucible at an appropriate time according to the progress of melting. It becomes possible.

  Further, the hot water control apparatus according to the present invention is a non-conductor at normal temperature, silicon or ceramic that becomes conductive at a temperature higher than normal temperature as a melting raw material, a melting part for melting the melting raw material, A crucible formed of a material that allows magnetic flux to permeate, and a crucible formed of a material that allows magnetic flux to permeate, and is housed in the crucible. A hot water control apparatus for controlling a hot water start time of a heating and melting apparatus, comprising: a heating means for heating the melting raw material, and a coil that is arranged around the hot water portion and that is supplied with an alternating current; It is characterized by comprising detection means for detecting a change in inductance, and control means for controlling the start time of hot water based on a detection signal from the detection means.

  According to such a control means, in addition to being able to predict the hot water start time early as described above, it becomes possible to start hot water at an appropriate time according to the progress of melting. .

It is a mimetic diagram showing a 1st embodiment of a heating dissolution device. It is a graph which shows the temperature characteristic of the electrical resistivity of a silicon | silicone and carbon felt. It is a circuit diagram which shows the structure of the power supply of the coil for hot water. It is a schematic diagram which shows the magnetic flux line which penetrates the coil for hot water. It is a graph which shows the change of the resonant frequency of the power supply accompanying progress of melt | dissolution. It is a schematic diagram which shows 2nd Embodiment of a heat-dissolution apparatus. It is a schematic diagram which shows 3rd Embodiment of a heat-dissolution apparatus. It is a mimetic diagram showing an embodiment of a heating dissolution system. It is a schematic diagram which shows embodiment of the hot water control apparatus.

[First Embodiment]
(Overall configuration)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a first embodiment of a heating and melting apparatus. The heating and melting apparatus 100 is an apparatus for melting a melting raw material charged in a quartz crucible 10 by induction heating in a vacuum. As a melting raw material, silicon used for semiconductor devices and ceramics such as alumina and zirconia used for jewelry can be targeted. In this embodiment, the case where silicon S is used as a melting raw material will be described as an example. To do.

  The crucible 10 is composed of a melting part 20 having a cylindrical shape and a tapping part 30 having an inverted conical shape located below the melting part 20, and a tapping opening 30 a is formed at the bottom of the tapping part 30. Yes. A melting coil 21 made of a high frequency induction coil is wound around the melting portion 20, and a high frequency current having a frequency of about 10 to 40 kHz is supplied to the melting coil 21 from a high frequency power source 22. A cylindrical heating element 23 made of carbon felt or porous carbon is disposed between the outer peripheral surface of the melting portion 20 and the melting coil 21.

  A hot water discharge coil 31 made of a high frequency induction coil is wound around the hot water supply section 30, and a high frequency current having a frequency of, for example, about 10 to 40 kHz is supplied from the high frequency power supply 32 to the hot water supply coil 31. A frequency detection means 42 is connected to the circuit of the high frequency power supply 32, and the frequency of the alternating current supplied to the hot water discharge coil 31 can be detected. Detailed configurations of the high frequency power supply 32 and the frequency detection means 42 will be described later. Further, an inverted conical heating element 33 made of carbon felt or porous carbon is disposed between the outer peripheral surface of the hot water portion 30 and the hot spring coil 31.

  A disc-shaped shield member 11 extending from the outer peripheral surface of the crucible 10 is provided between the region around which the melting coil 21 is wound and the region around which the hot spring coil 31 is wound. Yes. The shield member 11 is formed of, for example, a water-cooled copper plate and prevents interference between the high frequency power sources 22 and 32. Note that the frequency of the high-frequency current supplied to the melting coil 21 and the frequency of the high-frequency current supplied to the tapping coil 31 may be different. For example, by setting these frequencies to values that do not easily interfere with each other. The shield member 11 can be omitted.

(Principle of dissolution)
In the heating and melting apparatus 100 configured as described above, when a high frequency current is first supplied to the melting coil 21 by the high frequency power source 22, a magnetic flux penetrating the melting coil 21 is generated. The crucible 10 made of quartz, which is a non-conductor, transmits this magnetic flux. Moreover, in the heat generating body 23 with many air gaps, since the attenuation of the magnetic flux is gentle, the magnetic flux is sufficiently transmitted. Therefore, the magnetic flux from the melting coil 21 can reach the silicon S in the crucible 10.

  Here, FIG. 2 is a graph showing the temperature characteristics of the electrical resistivity ρ of silicon and carbon felt. Silicon is a non-conductor having a very high electrical resistivity ρ at room temperature, and the electrical resistivity ρ decreases with increasing temperature, and becomes conductive. On the other hand, the electrical resistivity ρ of carbon felt hardly changes with temperature, and is about 5.3 × 105 μΩ · cm, which is an intermediate value between electrical resistivity ρ at room temperature and melting point (1410 ° C.) of silicon. Regarding the electrical resistivity ρ of silicon, the region of room temperature to 1000 ° C. indicated by the solid line and the region of 1410 ° C. (melting point) or more are actually measured, and the region of 1000 ° C. to 1410 ° C. indicated by the dotted line is The measured values of 1000 ° C. and 1410 ° C. are connected by a straight line for convenience. In addition, although illustration is abbreviate | omitted, the electrical resistivity of porous carbon also has the temperature characteristic similar to a carbon felt.

  Therefore, at the initial stage of heating when the electrical resistivity ρ of the silicon S is large, the heating element 23 formed of carbon felt or porous carbon is induction-heated by the melting coil 21 and the radiant heat and heat conduction from the heating element 23 whose temperature has increased. Thus, the silicon S in the crucible 10 can be indirectly heated. On the other hand, when the silicon S is indirectly heated and the temperature rises, the electrical resistivity ρ is lowered and becomes conductive, so that the silicon S can be directly heated by induction. Therefore, silicon S can be efficiently dissolved. Further, the heating element 23 formed of carbon felt having a large number of voids or porous carbon also functions as a heat insulating material, and has an effect of keeping the liquid silicon S1 in the melting portion 20 warm and preventing solidification.

  When the silicon S is melted by the melting coil 21 in this manner, the silicon S existing in the melting portion 20 of the crucible 10 is eventually melted to become liquid silicon S1 and undissolved solid silicon Ss is formed in the hot water portion 30. It will remain. As a result, an interface I is formed between the liquid silicon S1 and the solid silicon Ss. The solid silicon Ss in the vicinity of the interface I is dissolved by heat transfer from the liquid silicon S1, and the dissolution of the silicon S proceeds in such a form that the interface I gradually moves downward.

  When the melting of the silicon S proceeds to some extent by the melting coil 21, the high frequency power supply 32 starts to supply a high frequency current to the hot water discharge coil 31. Note that the supply of the high-frequency current to the melting coil 21 may be stopped simultaneously with the start of the supply of the high-frequency current to the tapping coil 31. By supplying a high frequency current to the hot spring coil 31, the hot water coil 31 can perform induction heating of the silicon S in the hot water section 30, and promote the dissolution of the solid silicon Ss in the hot water section 30. it can.

  Further, by providing the heating element 33 made of carbon felt or porous carbon, the silicon S can be efficiently dissolved, and the liquid silicon S1 in the hot water portion 30 is kept warm to prevent solidification. You can also. The principle is the same as that of the heating element 23 described above, and a description thereof is omitted here.

(Power supply configuration)
FIG. 3 is a circuit diagram showing the configuration of the high-frequency power source 32 of the hot spring coil 31. The high frequency power supply 32 includes a forward conversion unit 34 that rectifies an alternating current supplied from an external alternating current power source, a smoothing unit 35 that smoothes the rectified current to generate a direct current, and an inverse conversion that converts direct current power into alternating current power. It has the capacitor | condenser 37 which forms the resonance circuit 39 with the part 36 and the coil 31 for hot water supply. The resonance circuit 39 also includes a resistor 38 that constitutes a load together with the hot spring coil 31. The high frequency power supply 32 is a resonance type power supply that supplies AC power of a predetermined frequency to the resonance circuit 39 so that the resonance circuit 39 resonates at the resonance frequency f, and has a frequency higher than the AC current from the external AC power supply. Supply current. Note that the high frequency power supply 22 can also be configured as a resonant power supply, similar to the high frequency power supply 32.

  The voltage generated in the resonance circuit 39 is input to the frequency detection means 42 via the transformer 41, and the resonance frequency f in the resonance circuit 39 is calculated by the frequency detection means 42. Then, the control unit 43 feedback-controls the operation of the inverse conversion unit 36 based on the resonance frequency f so that the resonance circuit 39 can maintain the resonance state, and supplies power of a predetermined frequency to the resonance circuit 39. By maintaining the resonance in this way, a high-frequency current can be efficiently supplied to the hot spring coil 31, and the power supply capacity can be reduced. Here, the voltage of the resonance circuit 39 is extracted and feedback control is performed based on the voltage. However, the current of the resonance circuit 39 may be extracted and feedback control may be performed based on the current.

  Display means 44 and input means 45 are connected to the control means 43, respectively. In addition to the feedback control described above, the control means 43 calculates the position of the interface I, the hot water start time, etc. based on the change in the resonance frequency f, or controls the power supplied to the hot water coil 31. It has a function to control the hot water start time. And the calculation result regarding the position of the interface I calculated by the control means 43, the hot water start time, etc. is displayed on the display means 44. Further, an instruction regarding a desired hot water start timing is input to the control means 43 via the input means 45.

(Prediction of hot spring start time)
FIG. 4 shows the magnetic flux lines penetrating through the hot spring coil 31 with dotted lines. FIG. 4b shows the state in which the dissolution of the silicon S has progressed more than the figure a and the interface I has moved downward. In FIG. 4, parts other than the crucible 10 and the hot spring coil 31 are not shown in order to clearly show the magnetic flux lines.

  In the heating and melting apparatus 100, the crucible 10 is made of non-conductive quartz that transmits magnetic flux, and non-conductive silicon S is used as a melting material at room temperature. For this reason, the magnetic flux from the hot water discharge coil 31 disposed around the hot water discharge portion 30 is hardly attenuated by the crucible 10 or the normal temperature silicon S and penetrates deep into the crucible 10. When the magnetic flux reaches the vicinity of the interface I, the temperature rises due to heat transfer from the liquid silicon S1 or the like, and the solid silicon Ss whose electric resistivity decreases, or the liquid silicon that dissolves and decreases the electric resistivity. Eddy current is generated in Sl, and the magnetic flux is attenuated. For this reason, as melting progresses and the interface I moves downward, the number of interlinkage magnetic fluxes penetrating through the tapping coil 31 decreases, and as a result, the inductance of the tapping coil 31 decreases.

Here, the resonance frequency f of the resonance circuit 39 is expressed by the following equation (1) using the inductance L of the coil 31 for hot water and the capacitance C of the capacitor 37.
f = 1 / (2π√LC) (1)
That is, when the interface I moves downward and the inductance L of the hot water discharge coil 31 decreases, the resonance frequency f increases. Therefore, the movement state of the interface I can be grasped by detecting the resonance frequency f of the resonance circuit 39 by the frequency detection means 42. At this time, as described above, in the heating and melting apparatus 100, since the magnetic flux from the tap water coil 31 arranged around the tap water portion 30 penetrates deeply to the interface I, the change in inductance due to the movement of the interface I is detected from an early stage. As a result, the start time of the hot water can be predicted early.

(Comparison of changes in resonance frequency)
FIG. 5 is a graph showing changes in the resonance frequency of the high-frequency power source 32 as the melting progresses. The transition of the resonance frequency in the heating and melting apparatus 100 of the present embodiment is shown by a bold line, and for comparison, the transition of the resonance frequency in the cold crucible melting apparatus of Patent Document 2 is shown by a thin line. In both devices, the hot water supply is started after 40 seconds and the hot water is completed after 60 seconds by starting the supply of current to the hot water coil at the timing (0 second) described as “power on” in the figure. Although it is set as a condition, more precisely, a change in resonance frequency is detected by supplying a minute current from before 0 seconds.

  In the cold crucible melting apparatus, the resonance frequency remains constant from the beginning of melting. As described above, in the cold crucible melting device, since the penetration depth of the magnetic flux from the coil for hot water is shallow, until the interface between the skull and the solution enters the shallow penetration depth, that is, the skull is This is because a change (decrease) in the resonance frequency cannot be detected until the thickness becomes very thin. Therefore, the power-on timing is not determined based on the change in the resonance frequency, but is determined in advance as the time when a predetermined time has elapsed since the start of melting. The predetermined time is set to a time that surely exceeds the time from the start of dissolution until the interface between the skull and the solution is in an equilibrium state, that is, until the interface is not lowered any further. .

  A short time after turning on the power, a decrease in the resonance frequency is observed. This is a phenomenon that occurs when the supply of current to the tapping coil starts and the interface further falls from the equilibrium state, and the interface reaches within the penetration depth of the magnetic flux from the tapping coil. And since the skull has already become very thin at the time when such a decrease in the resonance frequency is seen, the skull is completely dissolved immediately after that, and the tapping of the solution starts. And as the hot water of the dissolving liquid that attenuates the magnetic flux advances, the magnetic flux from the hot water coil penetrates deeply, and the inductance of the hot water coil increases. This increase in inductance appears as a decrease in resonance frequency after 50 seconds. When the hot water of the solution is completed, the resonance frequency becomes constant.

  On the other hand, in the heating and melting apparatus 100 of the present embodiment, it is observed that the resonance frequency gradually increases from an extremely early stage. This is because the crucible 10 is made of quartz that transmits magnetic flux and non-conductive silicon S is used as a melting material at room temperature, so that the magnetic flux from the coil 31 for hot water penetrates deeply and the position of the interface I changes. This is because it appears early as a change in the resonance frequency. In FIG. 5, for the sake of space, only the transition after minus 60 seconds is shown, but an increase in resonance frequency can be observed before minus 60 seconds. Thus, since the change (increase) in the resonance frequency can be detected from an early stage, it is possible to determine at an early stage when the current supply to the hot water discharge coil 31 is started while observing the change.

  Here, when the resonance frequency reaches 9.02 kHz, the current supply to the hot water discharge coil 31 is started. By supplying a current to the hot spring coil 31, melting of the solid silicon Ss in the hot water portion 30 is promoted, and the increase rate of the resonance frequency is increased. Then, after about 40 seconds, the melting of the solid silicon Ss in the hot water 30 is completed, and the resonance frequency reaches a peak. Thereafter, as the pouring of the liquid silicon S1 that attenuates the magnetic flux proceeds, the magnetic flux from the pouring coil 31 penetrates deeply, and the inductance of the pouring coil 31 increases. As a result, the resonance frequency of the high frequency power supply 32 is lowered. Then, when the pouring of the liquid silicon S1 is completed, the resonance frequency becomes constant.

  Thus, it was confirmed that the heating and melting apparatus 100 of this embodiment can detect a change (increase) in the resonance frequency very early compared to the cold crucible melting apparatus. For this reason, in the heating and melting apparatus 100, the timing for starting the supply of current to the hot water discharge coil 31 can be determined early based on the change in the resonance frequency. And since the start time of the electric current supply to the coil 31 for hot water can be determined at an early stage, the subsequent hot water start time can be predicted early.

  Further, since the position of the solidification interface I which is the boundary between the solid silicon Ss layer and the liquid silicon S1 layer can be known from the change in the resonance frequency, for example, before the solidification interface I moves to the equilibrium position, By supplying a current to 31, the time until the solidification interface I moves to the equilibrium position can be shortened. That is, since the start timing of current supply to the hot water discharge coil 31 can be set so as to shorten the time until the solidification interface I is in an equilibrium state, it is particularly effective when silicon S is continuously melted. Is.

  In the cold crucible melting apparatus, the solution adhering to the inner wall of the crucible may be re-solidified by the cold heat from the crucible. For this reason, the work for removing the raw material adhering to the crucible was necessary after completion of the hot water. However, the heating and melting apparatus 100 does not use a water-cooled crucible and the solution does not re-solidify, so that the above-described operation is not necessary. Therefore, if it is determined that the resonance frequency is constant and the hot water is completed, the silicon S can be subsequently introduced into the crucible 10 and the silicon S can be continuously dissolved. At this time, as described above, since the start time of the hot water can be predicted early, the end time of the hot water can be grasped at an early stage, and preparation for additional charging of silicon S can be efficiently performed. Further, when the liquid silicon S1 adhering to the quartz crucible 10 is re-solidified, the crucible 10 may be damaged due to a difference in thermal expansion coefficient between the silicon S and the crucible 10. However, in the heating and melting apparatus 100, since the liquid silicon S1 does not resolidify as described above, the crucible 10 can be prevented from being damaged.

  As described above, according to the heating and melting apparatus 100, since the movement state of the interface I can be grasped as a change in the resonance frequency of the resonance circuit 39 long before the silicon S is completely dissolved, the start timing of the hot water is positively determined. Control by the control means 43 is also possible. For example, when the increase rate of the resonance frequency is slow and the progress of melting is considered to be slower than planned, the progress of melting can be increased by increasing the power supplied from the high-frequency power supply 32. Alternatively, the power supplied from the upper high frequency power supply 22 may be increased. In this way, by controlling the hot water start timing, it becomes possible to start hot water at an appropriate time according to the progress of melting. Such control may be automatically performed by the control unit 43 or may be manually performed by an instruction via the input unit 45.

  It is also possible to control the start time of the hot water by providing a lid member (not shown) that can be opened and closed at the hot water outlet 30a, and controlling the opening and closing of the lid member. In this case, for example, when the resonance frequency no longer changes, it can be determined that all the silicon S has been dissolved, and the lid member can be opened. By performing such control, it is possible to prevent the hot water from being discharged in a state where the solid silicon Ss is mixed in the liquid silicon S1, and the solid silicon Ss flows out from the hot water outlet 30a, or the solid silicon Ss is discharged from the hot water outlet 30a. Can be avoided.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. The heating and melting apparatus 200 according to the second embodiment is different from the heating and melting apparatus 100 according to the first embodiment in that one induction heating coil 51 serving as the melting coil 21 and the tapping coil 31 is provided, and the induction heating coil 51 is not used. It is the point which is comprised with respect to the crucible 10 by the raising / lowering mechanism of illustration. In addition, the same number is attached | subjected about the component similar to 1st Embodiment, and the description is abbreviate | omitted.

  The induction heating coil 51 has a diameter slightly larger than the outer diameter of the melting portion 20 of the crucible 10 and is configured to be able to move up and down around the crucible 10 by a lifting mechanism (not shown). The high frequency power supply 52 is configured in the same manner as the high frequency power supply 32 shown in FIG. 3, but the illustration of the frequency detection means 42, the control means 43, etc. is omitted here. The high-frequency power source 52 can also be moved up and down with respect to the crucible 10 integrally with the induction heating coil 51.

  First, in a state where the induction heating coil 51 and the high-frequency power source 52 are arranged around the melting part 20 of the crucible 10, a high-frequency current is supplied from the high-frequency power source 52 to the induction heating coil 51 to start melting of silicon S. When the melting proceeds to some extent and mainly the silicon S in the melting part 20 is melted, the induction heating coil 51 and the high frequency power source 52 are lowered and arranged around the hot water discharge part 30. Then, when a high frequency current is supplied from the high frequency power source 52 to the induction heating coil 51, the melting of the silicon S in the tapping part 30 proceeds.

  According to the heating and melting apparatus 200 of the second embodiment, not only can the hot water start time be predicted early as in the heating and melting apparatus 100 of the first embodiment, but also the following effects can be obtained. That is, in the heating and melting apparatus 200, it is only necessary to prepare one high-frequency power supply 52, so that the apparatus cost can be reduced and the installation space for the apparatus can be easily secured. In addition, since the interference due to the provision of a plurality of power supplies does not occur, the shield member 11 (see FIG. 1) can be omitted.

  Here, the induction heating coil 51 and the high frequency power source 52 are configured to be movable up and down with respect to the crucible 10, but the crucible 10 may be configured to be movable up and down with respect to the induction heating coil 51 and the high frequency power source 52, Or you may comprise both so that raising / lowering is possible. Further, if the wiring between the induction heating coil 51 and the high frequency power source 52 has a sufficient length, the induction heating coil 51 alone may be raised and lowered relative to the crucible 10 without raising and lowering the high frequency power source 52.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. The heating and melting apparatus 300 according to the third embodiment is different from the heating and melting apparatus 100 according to the first embodiment in that a high frequency current is supplied to the melting coil 21 and the tapping coil 31 with one high frequency power supply 62. Is a point. In addition, the same number is attached | subjected about the component similar to 1st Embodiment, and the description is abbreviate | omitted.

  The high frequency power supply 62 is configured in the same manner as the high frequency power supply 32 shown in FIG. 3, but the illustration of the frequency detection means 42, the control means 43, etc. is omitted here. A matching portion 63 for the melting coil 21 is provided between the melting coil 21 and the high-frequency power source 62, and a matching portion 64 for the tapping coil 31 is provided between the hot-water coil 31 and the high-frequency power source 62. Is provided. The matching units 63 and 64 are parts for adjusting the power from the high-frequency power source 62 to the power suitable for the coils 21 and 31, and are constituted by a circuit having a transformer and a capacitor, for example.

  The high-frequency current from the high-frequency power source 62 can be switched between a state supplied to the melting coil 21 and a state supplied to the tapping coil 31 by the switching unit 65. First, the switching unit 65 is switched to the melting coil 21 side, a high-frequency current from the high-frequency power source 62 is supplied to the melting coil 21 through the matching unit 63, and melting of the silicon S is started. When the melting progresses to some extent and mainly the silicon S in the melting portion 20 is melted, the switching portion 65 is switched to the hot water coil 31 side, and the high frequency current from the high frequency power source 62 is supplied to the hot water coil 31 via the matching portion 64. Then, the silicon S in the hot water supply unit 30 is dissolved.

  According to the heating and melting apparatus 300 of the third embodiment, not only can the hot water start time be predicted early as in the heating and melting apparatus 100 of the first embodiment, but also the following effects can be obtained. That is, in the heating and melting apparatus 300, it is only necessary to prepare one high-frequency power supply 62, so that the apparatus cost can be reduced and the installation space for the apparatus can be easily secured. In addition, since the interference due to the provision of a plurality of power supplies does not occur, the shield member 11 (see FIG. 1) can be omitted.

  Here, the matching portion 63 for the melting coil 21 and the matching portion 64 for the tapping coil 31 are provided outside the high-frequency power source 62, but these may be used as a common matching portion. In addition, the common matching portion may be provided in the high frequency power supply 62.

[Fourth Embodiment]
With reference to FIG. 8, a heating and melting system including the heating and melting apparatus described so far will be described as a fourth embodiment of the present invention. The heating and melting system 1 includes the heating and melting apparatus 100 described in the first embodiment. Instead of the heating and melting apparatus 100, the heating and melting apparatuses 200 and 300 described in the second and third embodiments are used. It may be provided.

  The heating and melting system 1 includes a heating and melting apparatus 100, a raw material charging control unit 70, and a raw material charging unit 80 provided above the crucible 10. The material charging control means 70 is connected to the frequency detection means 42, and silicon S is supplied from the material charging means 80 to the crucible 10 based on the change in the resonance frequency f of the resonance circuit 39 detected by the frequency detection means 42. Control the timing of charging. The raw material charging means 80 includes a container 81 for storing silicon S, and an opening / closing member 82 provided below the container 81 and opened and closed in response to a command from the raw material charging control means 70.

  For example, when a change in the resonance frequency f as shown in FIG. 5 is detected, the raw material charging control means 70 opens the opening / closing member 82 60 seconds after the supply of current to the hot water discharge coil 31 is started. Sends a command to the raw material charging means 80. That is, the raw material charging control means 70 predicts the time at which the hot water is completed from the change in the resonance frequency f, and issues a command to open the opening / closing member 82 immediately after that time. By doing so, the silicon S can be poured into the crucible 10 from the container 81 at an appropriate time, for example, immediately after the completion of pouring, depending on the progress of melting, and the silicon S can be continuously melted.

  In the present embodiment, the raw material input control means 70 is provided separately from the control means 43 of FIG. 3, but a control means that also serves as the control means 43 and the raw material input control means 70 may be provided. Similarly to the control means 43, a display means and an input means are connected to the raw material input control means 70 so that the operator can be notified of the next silicon S input scheduled time via the display means or via the input means. An operator may be allowed to input an instruction.

[Fifth Embodiment]
With reference to FIG. 9, the case where the object of the present invention is a tapping controller 91 as a tapping controller will be described as a fifth embodiment of the present invention. The hot water control controller 91 is connected to the high frequency power supply 32 of the heating and melting apparatus 100 described in the first embodiment, and includes a frequency detection means 92 and a control means 93. In FIG. 9, components other than the crucible 10, the hot spring coil 31, and the high frequency power source 32 among the constituent requirements of the heating and melting apparatus 100 are not shown.

  The frequency detection unit 92 has the same configuration as the frequency detection unit 42 of the first embodiment, and the control unit 93 has the same configuration as the control unit 43 of the first embodiment. That is, the hot water control controller 91 controls the hot water start time of the heating and melting apparatus 100 based on the change in the inductance of the hot water coil 31.

  Note that the tapping controller 91 may be provided for the heating and melting apparatuses 200 and 300 described in the second and third embodiments instead of the heating and melting apparatus 100. Further, the hot water control controller 91 can be configured such that the high frequency power supply 32 is not included in the heating and melting apparatus 100 but is included in the hot water control controller 91.

[Other variations]
In the above embodiment, the crucible 10 is made of quartz. However, the crucible 10 may be formed of other materials as long as the material transmits magnetic flux. For example, the crucible 10 may be formed of a metal oxide such as alumina or zirconia or a composite thereof. However, since impurities such as alumina and zirconia may be mixed in the melting raw material, it is necessary to select an appropriate material according to the purpose of melting and the raw material.

  In the above embodiment, the high frequency power supply 32 is described as being included in the heating and melting apparatus 100. However, the provision of the high frequency power supply 32 in the heating and melting apparatus 100 is not an essential requirement. For example, when the heating and melting apparatus 100 is incorporated in another apparatus, the other apparatus may be provided with a power supply having a function equivalent to that of the high-frequency power supply 32.

  In the above embodiment, the resonance type power supply is used. However, in the present invention, the use of the resonance type power supply is not an essential requirement. For example, when a power source having a fixed frequency is used, it is possible to detect a change in the inductance of the hot spring coil 31 based on a change in the current flowing through the hot spring coil 31. Moreover, you may detect the change of the inductance of the coil 31 for hot water supply by the change of a voltage.

  In the above embodiment, the melting coil 21 made of a high-frequency induction coil is used as the heating means. However, the heating means can be constituted by a heater or the like. Further, auxiliary heating means may be provided above the crucible 10. Moreover, in the said embodiment, although the coil 31 for hot water was a high frequency induction coil and it comprised so that the silicon | silicone S could be induction-heated by the coil 31 for hot water, giving the coil 31 for hot water has such an induction heating function. Is not required. That is, any coil may be used as long as the inductance changes according to the change in the position of the interface I. In addition to the coils 21 and 31 in the first and third embodiments and the coil 51 in the second embodiment, a coil for detecting a change in the position of the interface I may be separately provided.

  In the above embodiment, the heating elements 23 and 33 made of carbon felt or porous carbon are provided, but the heating elements 23 and 33 may be omitted. Only one of the heating elements 23 and 33 may be provided.

  Alternatively, the crucible 10 may be formed by forming the heating elements 23 and 33 made of carbon felt or porous carbon into a bottomed cylindrical container and covering the inner surface of the container with a metal thin film. Although the metal itself is a conductor, the magnetic flux can be transmitted through the crucible 10 by making the thickness sufficiently thinner than the penetration depth of the magnetic flux.

  In addition, the shape, arrangement, number, and the like of each member can be appropriately changed as long as the function is not impaired.

1 Heating and melting system 10 Crucible 20 Melting part 21 Melting coil (heating means)
22 High Frequency Power Supply 23 Heating Element 30 Hot Water Portion 31 Coil for Hot Water (Coil)
32 High frequency power supply
33 Heating element 42 Frequency detection means (detection means)
43 Control means 46 Hot water control controller (hot water control device)
70 Raw material charging control means 80 Raw material charging means 100, 200, 300 Heating and melting apparatus S Silicon (melting raw material)

Claims (6)

In a heating and melting apparatus using silicon or ceramic as a melting raw material which is a non-conductor at normal temperature and becomes conductive at a temperature higher than normal temperature,
A melting part that dissolves the melting raw material, a crucible that is located below the melting part and has a tapping part in which a tapping outlet is formed at the bottom, and is formed of a material that transmits magnetic flux;
A heating means for heating the melting raw material disposed around the melting portion and housed in the crucible;
A coil disposed around the tapping part and having a function of inductively heating the melting raw material with a high-frequency current ;
Detecting means for detecting a change in inductance of the coil;
Equipped with a,
Heating and melting characterized by detecting a downward movement of an interface formed between the melting raw material and the solid melting raw material by detecting a change in inductance of the coil by the detecting means apparatus. The heating and melting apparatus according to claim 1 , wherein a heating element formed of carbon felt or porous carbon is provided between the hot water outlet and the coil.   The heating means is a melting coil;
  A high frequency power source for supplying a high frequency current to the coil and the melting coil;
  A switching unit that switches between a state in which a high-frequency current from the high-frequency power source is supplied to the coil and a state in which the high-frequency current is supplied to the melting coil;
  The heating and melting apparatus according to claim 1, further comprising:   The heating and melting apparatus according to any one of claims 1 to 3, further comprising a control unit that controls a hot water start timing based on a detection signal from the detection unit. The heating and melting apparatus according to any one of claims 1 to 4,
Raw material charging means for charging the melting raw material into the crucible;
Based on a change in inductance of the coil detected by the detection means, raw material charging control means for controlling the timing of charging the melting raw material from the raw material charging means to the crucible;
A heating and melting system comprising: Silicon or ceramic that is non-conductive at normal temperature and becomes conductive at higher temperature than normal temperature is used as a melting raw material,
A melting part that dissolves the melting raw material, a crucible that is located below the melting part and has a tapping part in which a tapping outlet is formed at the bottom, and is formed of a material that transmits magnetic flux;
A heating means for heating the melting raw material disposed around the melting portion and housed in the crucible;
A coil disposed around the tapping part and having a function of inductively heating the melting raw material with a high-frequency current ;
In the hot water control device for controlling the hot water start time of the heating and melting device having
Detecting means for detecting a change in inductance of the coil;
Based on the detection signal from the detection means, a control means for controlling the hot water start time,
Equipped with a,
The hot water control characterized by detecting a downward movement of an interface formed between the molten raw material and the solid molten raw material by detecting a change in inductance of the coil by the detecting means. apparatus.