Combustion synthesis furnace

Abstract

To provide a burning synthetic furnace which can reduce a time taken for cooling, and additionally, to provide a burning synthetic furnace which enables simultaneous ignition with respect to a raw material in plural crucibles installed in a chamber to improve production efficiency.SOLUTION: A burning synthetic furnace (1) for synthesizing an inorganic compound with respect to a raw material filled into crucibles by a burning synthesis method comprises: a multistage rack (2) which can arrange the crucible into plural stages; a stage (3) which mounts the multistage rack; and a chamber (4) which can store the multistage rack at the inside, wherein the multistage rack is detachably attached to the stage.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a combustion synthesis furnace for synthesizing inorganic compounds by a combustion synthesis method.

Background Art

[0002] For example, aluminum nitride (AlN) and silicon nitride (Si3N4) have high insulation and high thermal conductivity, and are thus applied as high heat dissipation fillers and the like. AlN and Si3N4 can be produced by a combustion synthesis method in which a synthesis reaction proceeds by self-generated heat.

[0003] Conventionally, in order to increase productivity, the crucible was made multi-stage to increase the processing volume. At this time, when performing the operation of recovering the crucible from each stage, since it would directly touch the crucible as the heat generation part, it was necessary to cool the crucible to a temperature range where burns would not occur in consideration of work safety. In Patent Document 1, a configuration is disclosed in which crucibles are stacked in multiple stages in a reaction vessel (chamber), and the cooling effect is enhanced by a cooling jacket provided on the wall of the reaction vessel.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the configuration of Patent Document 1, since the crucibles are sequentially cooled in the reaction vessel, there is a problem that the processing time is long. Further, in the configuration of Patent Document 1, an introduction chamber for feeding the crucible into the reaction vessel and a recovery chamber for taking out the crucible from the reaction vessel are provided, and the mechanism for moving the crucible from the introduction chamber through the reaction vessel to the recovery chamber has become complicated. Also, high control is considered necessary to smoothly move the crucible between the chambers.

[0006] Furthermore, conventionally, only one ignition point was provided for each raw material in multiple stacked crucibles. Similarly, in Patent Document 1, only one ignition device is provided at the top of the reaction vessel. In this configuration, the ignition device is activated sequentially for the raw materials filled in the crucibles sent into the reaction vessel to perform combustion synthesis, so it was not possible to effectively increase production efficiency.

[0007] Therefore, the present invention has been made in view of the above problems, and aims to provide a combustion synthesis furnace that can shorten the cooling time. In addition, the present invention aims to provide a combustion synthesis furnace that enables simultaneous ignition of raw materials in multiple crucibles installed in the chamber, thereby improving production efficiency. [Means for solving the problem]

[0008] The present invention relates to a combustion synthesis furnace for synthesizing inorganic compounds by a combustion synthesis method using raw materials packed in a crucible, comprising a multi-stage rack capable of arranging multiple crucibles in stages, a stage on which the multi-stage rack is placed, and a chamber capable of housing the multi-stage rack inside, wherein the multi-stage rack is detachable from the stage. Each tier of the multi-tier rack is provided with an electrode rail, and a filament for igniting the raw material can be attached to any position on the electrode rail, and the multi-tier rack is provided with a suspension section for attaching to and detaching from the stage. It is characterized by the following:

[0010] In the present invention, the chamber is configured to slide open and closed laterally, and it is preferable that the multi-stage rack be attached to and detached from the stage from the height direction when the chamber is open. In the present invention, the multi-tier rack is preferably made of CC composite, titanium, or stainless steel. [Effects of the Invention]

[0011] According to the combustion synthesis furnace of the present invention, a multi-stage rack capable of arranging multiple crucibles in stages is detachably supported from the stage, and the multi-stage rack can be removed outside the chamber. Therefore, multiple crucibles that have completed combustion synthesis can be removed together with the multi-stage rack and cooled at once, thereby shortening the processing time.

[0012] In addition, in this invention, electrode rails on which filaments can be attached are provided at the top of each tier of the multi-tier rack, allowing the position of the filaments to be set arbitrarily and multiple filaments to be attached to each electrode rail, thereby improving production efficiency. [Brief explanation of the drawing]

[0013] [Figure 1] This is an overall schematic diagram of the combustion synthesis furnace in this embodiment, and is a side view showing a multi-tiered rack suspended from the stage. [Figure 2] This is an overall schematic diagram of the combustion synthesis furnace in this embodiment, and is a side view showing the state in which the multi-stage rack is placed on the stage and the chamber is closed, compared to the state in Figure 1. [Figure 3] This is a perspective side view showing the multi-tiered racks and crucibles housed inside the chamber. [Figure 4] This is a perspective view of the multi-tier rack in this embodiment. [Figure 5] Figure 4 is a perspective view showing a crucible set up on a multi-tiered rack. [Figure 6] Figure 5 is a top view of the multi-tiered rack shown in Figure 5. [Modes for carrying out the invention]

[0014] Hereinafter, one embodiment of the present invention (hereinafter abbreviated as "Embodiment") will be described in detail. It should be noted that the present invention is not limited to the following embodiment, and can be implemented with various modifications within the scope of its gist.

[0015] <Problems with conventional combustion synthesis furnaces> In large-scale combustion synthesis furnaces, crucibles filled with raw materials are stacked in a multi-stage system, and crucibles are recovered sequentially as combustion synthesis is completed. However, because the crucibles are at high temperatures, it is necessary to cool each crucible individually before recovery, which results in a long processing time.

[0016] In the past, only one ignition point was provided for the combustion synthesis furnace, and the position of the ignition point was also fixed. For this reason, it was difficult to increase the production efficiency, and it was impossible to respond flexibly to the amount and type of raw materials, manufacturing conditions, and the like.

[0017] As shown in Patent Document 1, a plurality of crucibles filled with raw materials are sequentially conveyed into a reaction vessel. In the reaction vessel, the raw materials are ignited in the order of the accommodated crucibles, and then, a combustion synthesis furnace configured to take out the crucibles that have completed combustion synthesis and been cooled from the reaction vessel is disclosed.

[0018] However, in the configuration of the combustion synthesis furnace in Patent Document 1, since the crucibles that have completed combustion synthesis are sequentially cooled and recovered, the cooling treatment time cannot be effectively shortened. Also, there is only one ignition point, and the production efficiency cannot be effectively increased. In addition, the moving distance from when the crucible is carried into the reaction vessel to when it is taken out of the reaction vessel is long, and there is also concern about the risk of collapse or dropping of the raw materials placed in the crucible.

[0019] In view of the above-described conventional problems, the inventors of the present invention conducted intensive research and equipped the combustion synthesis furnace 1 with a multi-stage rack 2 on which a plurality of crucibles 5 can be arranged in multiple stages, thereby solving the conventional problems. That is, the combustion synthesis furnace 1 of the present embodiment includes a multi-stage rack 2 on which a plurality of crucibles can be arranged in multiple stages, a stage 3 on which the multi-stage rack 2 is placed, and a chamber 4 capable of accommodating the stage 3 and the multi-stage rack 2 inside, and the multi-stage rack 2 is detachable from the stage 3. Thereby, the multi-stage rack 2 can be freely removed, and the plurality of stages of crucibles 5 that have completed combustion synthesis can be cooled at once, and the processing time can be shortened. Also, it is possible to provide an ignition point for each stage, and it is possible to simultaneously ignite each raw material in the plurality of crucibles 5, thereby improving the production efficiency. Hereinafter, the configurations of the combustion synthesis furnace 1 and the multi-stage rack 2 in the present embodiment will be described with reference to the drawings.

[0020] <Regarding the combustion synthesis furnace 1 in the present embodiment> FIG. 1 is an overall schematic view of the combustion synthesis furnace 1 in the present embodiment. In particular, it is a side view showing the state where the chamber 4 is open and the multi-stage rack 2 is suspended from above the stage 3. FIG. 2 is an overall schematic view of the combustion synthesis furnace 1 in the present embodiment. In particular, it is a side view showing the state where the multi-stage rack 2 is placed on the stage 3 and the chamber 4 is closed from the state of FIG. 1. FIG. 3 is a perspective side view showing the multi-stage rack 2 and the crucible accommodated in the chamber 4.

[0021] As shown in FIGS. 1 to 3, the combustion synthesis furnace 1 includes a multi-stage rack 2 on which a plurality of crucibles 5 can be installed, a stage 3 on which the multi-stage rack 2 is placed, and a chamber 4 that can accommodate the multi-stage rack 2 and the stage 3.

[0022] Here, in each figure, the X1-X2 direction is the horizontal direction, the X1 direction is the left direction, and the X2 direction is the right direction. Also, the Y1-Y2 direction is the vertical direction, the Y1 direction is the front direction, and the Y2 direction is the depth direction. The Z1-Z2 direction is the height direction, the Z1 direction is the upward direction, and the Z2 direction is the downward direction. The X1-X2 direction, the Y1-Y2 direction, and the Z1-Z2 direction are in a mutually orthogonal relationship.

[0023] As shown in FIGS. 1 and 2, the chamber 4 and the stage 3 are installed above the base 6. The chamber 4 is supported on the base 6 so as to be able to slide in the horizontal direction (X1-X2 direction). For example, rails (not shown) are provided on the sixth surface, and the legs 4a of the chamber 4 can slide in the horizontal direction (X1-X2 direction) on the rails. In the present embodiment, the chamber 4 can be slid by automatic control. Note that the chamber 4 may be configured to be slid manually. FIG. 1 shows the state where the chamber 4 has moved to the right (X2 direction) and is open.

[0024] As shown in FIG. 1, the chamber 4 is provided with an opening 4c at the left end 4b, and the rest is closed. The chamber 4 is substantially cylindrical, and a recess 4d and a flange 4e are alternately provided on the outer surface of the left end 4b along the circumferential direction.

[0025] As shown in Figure 1, a lid 7 is provided on the left side (X1 side) of the base 6, opposite the chamber 4. The right end 7a of the lid 7, opposite the opening 4c of the chamber 4, is an opening 7b, and the opening 4c has alternating protrusions and recesses along its circumference. The recess 4d provided on the left end 4b of the chamber 4 and the protrusion provided on the opening 4c of the lid 7 are formed to be substantially the same shape, and similarly, the flange 4e provided on the left end 4b of the chamber 4 and the recess provided on the opening 4c of the lid 7 are formed to be substantially the same shape.

[0026] As shown in Figure 1, the lid 7 has a larger diameter space 7c formed inside its right end 7a, and the left end 4b of the chamber 4 can enter into this space 7c. That is, as shown in Figures 2 and 3, when the chamber 4 is slid to the left (X1 direction) from the state in Figure 1, the shape of the recess 4d and flange 4e provided on the left end 4b of the chamber 4 matches the shape of the irregularities provided on the opening 7b of the lid 7, and the left end 4b of the chamber 4 enters into the space 7c of the lid 7.

[0027] As shown in Figures 1 to 3, a side plate 8 is provided on the inside of the left end of the lid 7, and the left end 4b of the chamber 4, which has entered the space 7c of the lid 7, is in close contact with the side plate 8, forming a sealed space consisting of the chamber 4 and the lid 7.

[0028] Furthermore, the stage 3 is fixedly supported on the side plate 8 of the lid 7. As shown in Figure 1, the stage 3 protrudes away from the lid 7 (to the right (X2 direction)).

[0029] Since a multi-tiered rack 2, with crucibles 5 filled with raw materials arranged on each tier, is placed on the top surface of stage 3, stage 3 has sufficient strength to not deform or be damaged even when the multi-tiered rack 2 is placed on it.

[0030] Furthermore, the surface area of ​​Stage 3 is larger than that of the multi-tier rack 2, allowing the multi-tier rack 2 to be placed within the upper surface of Stage 3 without extending beyond its outer edge. In addition, both sides of Stage 3 are bent upward (in the Z1 direction), allowing the multi-tier rack 2 to be stably placed on Stage 3.

[0031] Although not shown in the diagram, the control unit, piping, switches, etc., are provided on the outside of the side plate 8 of the lid 7 (the side opposite to the side facing the chamber 4: the X1 side). Next, we will describe the structure of multi-tier rack 2 in detail.

[0032] [Multi-tier rack 2] Figure 4 is a perspective view of the multi-tier rack 2 in this embodiment. Figure 5 is a perspective view of the multi-tier rack 2 shown in Figure 4 with the crucible 5 set inside. Figure 6 is a top view of the multi-tier rack 2 shown in Figure 5.

[0033] As shown in Figure 4, the multi-tier rack 2 comprises several support columns 21 extending in the height direction (Z1-Z2 direction) and located at the corners of the multi-tier rack 2, several first horizontal beams 22 connecting the lower and upper ends of each support column 21 in the horizontal direction (X1-X2 direction), and several first vertical beams 23 connecting the lower and upper ends of each support column 21 in the vertical direction (Y1-Y2 direction).

[0034] Furthermore, the multi-tier rack 2 includes multiple second horizontal beams 24 positioned between the first horizontal beams 22 located at the upper and lower ends, and multiple second vertical beams 25 positioned between the first vertical beams 23 located at the upper and lower ends. In addition, a third vertical beam 26 is provided that vertically traverses (Y1-Y2 direction) between the first horizontal beams 22 and the second horizontal beams 24 located at each tier. These support columns 21 and each beam are assembled by welding or other means to form a multi-tier multi-tier rack 2. The multi-tier rack 2 shown in Figure 4 has a four-tier structure, but the number of tiers (shelves) is not limited. The height of each tier in the multi-tier rack 2 can also be set arbitrarily.

[0035] Furthermore, the multi-tier rack 2 has fall prevention columns 27 that extend approximately parallel to the support columns 21 at intermediate positions on the left side (X1 side), right side (X2 side), and back side (rear side (Y2 side)), fixed to and supported by each beam section. This effectively prevents crucibles 5 filled with raw materials from falling from the multi-tier rack 2 when they are placed on each tier, as shown in Figures 5 and 6. Note that the fall prevention columns 27 fixed to the multi-tier rack 2 are not provided on the front side (front side (Y1 side)) of the multi-tier rack 2. This allows crucibles 5 to be inserted into each tier of the multi-tier rack 2 from the front side. However, to prevent crucibles 5 from falling from the front side of the multi-tier rack 2, as shown in Figure 4, the first horizontal beam section 22 located at the lower and upper ends on the Y1 side of the multi-tier rack 2 is provided with regulating members 28 equipped with through holes 28a. As a result, after storing the crucible 5 in each tier of the multi-tier rack 2, a fall prevention column (not shown) can be passed through the through hole 28a to properly prevent it from falling from the front side (Y1 side) of the multi-tier rack 2.

[0036] As shown in Figure 4, multiple suspension parts 29 are provided on the upper surface of the multi-tier rack 2. The suspension parts 29 are fixed, for example, between the first vertical beam 23 and the third vertical beam 26 located at the upper end. The suspension parts 29 are, for example, plate-shaped and are fixedly supported in an upright position. As shown in Figure 4, holes 29a are provided in the suspension parts 29. As shown in Figure 1, the multi-tier rack 2 can be suspended by connecting a rope 9 to these holes 29a.

[0037] As shown in Figures 4 to 6, electrode rails 30 are provided above each tier. For example, the electrode rails 30 extend to the right (in the X2 direction) from the first vertical beam section 23 and the second vertical beam section 25 located on the left side (X1 side) of the multi-tier rack 2, and the connections with the vertical beam sections 23, 25, and 26 are insulated by insulating insulators. Two electrode rails 30 are provided for each tier. In this embodiment, each electrode rail 30 extends from the first vertical beam section 23 and the second vertical beam section 25 on the left side to the first vertical beam section 23 and the second vertical beam section 25 on the right side, but is not limited to this. For example, each electrode rail 30 may extend from the first vertical beam section 23 and the second vertical beam section 25 on the left side to a position in front of the first vertical beam section 23 and the second vertical beam section 25 on the right side (cantilevered).

[0038] Figure 5 shows the state in which crucibles 5 filled with raw materials are placed on each tier of the multi-tier rack 2 shown in Figure 4. Each time a crucible 5 is placed on a tier, a filament 31 is set between opposing electrode rails 30 above the crucible 5, as shown in Figures 5 and 6. For example, the filament 31 can be fixed between the electrode rails 30 using a fixing clip 32. When viewed from the side (X1-X2 direction), the filament 31 is bent downwards (Z2 direction) and is in contact with the surface of the raw material inside the crucible 5. The crucibles 5 are stored from the lower tier to the upper tier of the multi-tier rack 2, and the filament 31 is set each time a crucible 5 is stored. As shown in Figure 4, the multi-tier rack 2 is a frame structure consisting of support columns 21 and beam sections, so for example, the filament 31 can be set from directly above. Therefore, by sequentially storing the crucible 5 and setting up the filament 31 from the lower side, the crucible 5 can be easily arranged in a multi-tiered configuration, and the time required for arrangement can also be shortened.

[0039] As shown in Figure 3, power clips 33 are connected to the left end of the electrode rails 30 provided at each stage. Although not shown, the power clips 33 electrically connect the electrode rails 30 to a control panel (not shown) via wiring 34. By energizing the electrode rails 30, the filaments 31 are heated, and the raw materials filled in each crucible 5 are ignited, allowing a predetermined inorganic compound to be produced by combustion synthesis.

[0040] In this embodiment, the entire interior of the chamber 4 is not heated, but each crucible 5 arranged in the multi-stage rack 2 can be heated individually. Therefore, the entire interior of the chamber 4 does not become hot, and the multi-stage rack 2 does not need to have the same high-temperature resistance as ceramics or graphite; for example, it can be made of CC composite, titanium, or stainless steel. This makes it possible to manufacture a multi-stage rack 2 with excellent mechanical strength, and as shown in Figure 1, it is possible to improve work efficiency by suspending the multi-stage rack 2 and moving it to another location for work. CC composite is slightly less strong than titanium or stainless steel, but it can be used depending on the size and shape of the multi-stage rack 2. CC composite has the advantage of being lightweight and having high thermal conductivity, resulting in faster cooling. Titanium is also lightweight and preferable. Stainless steel is also cost-effective.

[0041] [Work process] The workflow from the end of one combustion synthesis to the start of the next will be explained using diagrams.

[0042] After the combustion synthesis is complete, as shown in Figure 1, the chamber 4 is slid to the right (X2 direction) to open the multi-stage rack 2 to the outside.

[0043] Next, as shown in Figure 1, a rope 9 is connected to the suspension section 29 of the multi-tier rack 2, lifting the multi-tier rack 2 upwards and separating it from the stage 3, and then it is removed from the combustion synthesis furnace 1.

[0044] Outside the combustion synthesis furnace 1, multiple crucibles 5 arranged in a multi-stage rack 2 are cooled. When the crucibles 5 have fallen below a predetermined temperature, each crucible 5 is removed from the multi-stage rack 2.

[0045] Next, a new crucible 5 filled with raw materials is placed in the multi-tier rack 2. At this time, as shown in Figure 6, the filaments 31 are connected between the electrode rails 30 of each tier, and the filaments 31 are brought into contact with the surface of the raw materials inside the crucible 5.

[0046] The multi-tier rack 2 is lifted by rope 9 and placed on stage 3. The power clips 33 shown in Figure 3 are connected to each electrode rail 30 of the multi-tier rack 2, and the chamber 4 is slid to the left (X1 direction) to place the multi-tier rack 2 inside the chamber 4. This completes the setup preparation before combustion synthesis.

[0047] For example, in this embodiment, AlN can be produced by combustion synthesis. In this case, a raw material mainly composed of Al is placed in a crucible 5, and with the filament 31 in contact with the surface of the raw material, the chamber 4 is degassed to a predetermined pressure. After that, nitrogen is purged to create a nitrogen pressurized atmosphere.

[0048] Next, an electric current is applied to the filament 31 connected to the electrode rail 30 for about 5 to 10 seconds until the raw material ignites, thereby initiating the combustion synthesis reaction between the Al in the raw material and nitrogen gas.

[0049] [Effects of the combustion synthesis furnace 1 in this embodiment] A distinctive feature of the combustion synthesis furnace 1 in this embodiment is that the multi-stage rack 2 is detachable from the stage 3.

[0050] As a result, in this embodiment, the multi-stage rack 2 can be transported outside the combustion synthesis furnace 1, and cooling work and crucible installation work can be performed outside, thus saving time.

[0051] Furthermore, in this embodiment, the crucible 5, which is in a high-temperature state after the combustion synthesis is complete, is placed on each tier of the multi-tier rack 2, so the crucible 5 does not need to be removed directly, and the multi-tier rack 2 can be removed instead. In this case, the multi-tier rack 2 itself does not become as hot as the crucible 5, and handling the multi-tier rack 2 is safer than directly handling the high-temperature crucible 5.

[0052] The production efficiency will now be explained. In this embodiment, electrode rails 30 are provided at the top of each tier of the multi-tier rack 2, and filaments 31 for igniting the raw materials filled in the crucibles 5 can be connected to any position on the electrode rails 30. In this way, in this embodiment, the position of the filaments 31 can be set arbitrarily, and multiple filaments 31 can be provided on the electrode rails 30 of each tier to create multiple ignition points. This makes it possible to shorten the combustion distance and thus shorten the synthesis time. Furthermore, in this embodiment, the raw materials in the crucibles 5 located on each tier of the multi-tier rack 2 can be ignited simultaneously, and the total time required to perform combustion synthesis on the raw materials in each crucible 5 can be shortened. When multiple ignition points are ignited simultaneously, it is preferable to provide a current value adjustment mechanism in the combustion synthesis furnace 1 so that the heat output of each filament 31 does not decrease. Furthermore, in this embodiment, since the multi-stage rack 2 is detachable from the stage 3, after the multi-stage rack 2 has finished combustion synthesis is removed from the combustion synthesis furnace 1, a new multi-stage rack 2 equipped with a crucible 5 filled with new raw materials can be brought into the combustion synthesis furnace 1 without delay. This reduces the time required to replace the crucible 5 inside the combustion synthesis furnace 1. As a result, production efficiency can be improved. In addition, since the position and number of filaments 31 can be freely changed, it is possible to respond flexibly to the amount and type of raw materials, manufacturing conditions, etc.

[0053] The present invention is not limited to the embodiments and modifications described above, and may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different way by advances in the art or by other derived arts, it may be implemented by that method. Accordingly, the claims cover all embodiments that may fall within the scope of the technical idea.

[0054] For example, the cooling device for cooling the multi-stage rack 2 may be provided to cool the inside of the chamber 4 after the completion of combustion synthesis.

[0055] Furthermore, the raw materials packed into the multiple crucibles 5 arranged in the multi-tier rack 2 may be the same or different. Therefore, the materials of the inorganic compounds produced by each crucible 5 may be different. [Industrial applicability]

[0056] The present invention can be preferably applied to combustion synthesis furnaces for producing inorganic compounds. [Explanation of Symbols]

[0057] 1: Combustion synthesis furnace 2: Multi-tiered rack 3: Stage 4: Chamber 4a: Legs 4b: Left end 4c: opening 4d: recessed 4e:Tsubabe 5: Crucible 6: stand 7: Lid 7a: Right edge 7b: Opening 7c: Space 8: Side panel 9: Rope 21: Strut 22: First crossbeam section 23: First vertical beam section 24: Second crossbeam section 25: Second longitudinal beam section 26: Third longitudinal beam section 27: Fall prevention pillar 28: Regulating member 28a: Through hole 29: Hanging section 29a: hole 30: Electrode Rail 31: Filament 32: Fixing clip 33: Power clip 34: Wiring

Claims

1. A combustion synthesis furnace for synthesizing inorganic compounds by combustion synthesis using raw materials packed in a crucible, A multi-tier rack capable of arranging the aforementioned crucibles in multiple tiers, A stage on which the aforementioned multi-tiered rack is placed, It has a chamber capable of housing the aforementioned multi-tier rack inside, The multi-tiered rack is detachable from the stage. Each tier of the aforementioned multi-tier rack is equipped with an electrode rail, A filament for igniting the raw material can be attached to any position on the electrode rail. A combustion synthesis furnace characterized in that the multi-stage rack is provided with a suspension part for attaching to and detaching from the stage.

2. The chamber is configured to be able to slide open and closed laterally. The combustion synthesis furnace according to claim 1, characterized in that the multi-stage rack is attached to and detached from the stage from the height direction when the chamber is open.

3. The combustion synthesis furnace according to claim 1 or 2, characterized in that the multi-stage rack is formed of CC composite, titanium, or stainless steel.

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