Treatment furnace
The furnace design addresses energy efficiency issues by transmitting microwaves through retort holes, reducing waveguide-related losses and ensuring uniform heating and stirring, thereby improving overall efficiency.
Patent Information
- Application Number
- JP2023209209
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-12-12
- Publication Date
- 2025-06-24
AI Technical Summary
Conventional microwave processing furnaces using waveguides suffer from reduced microwave output due to heat generation and thermal expansion, leading to decreased energy efficiency.
A processing furnace design that allows microwaves to enter a retort without using a waveguide by providing holes in the retort for microwave transmission, with chamfered corners and inward protrusions to prevent overheating and ensure uniform heating.
Enhances energy efficiency by preventing output reduction from waveguide heat generation and thermal expansion, ensuring uniform heating and improved stirring of objects within the retort.
Smart Images
Figure 2025093511000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a processing furnace that heats and processes an object to be processed with microwaves.
Background Art
[0002] As processing furnaces that heat an object to be processed with microwaves without using a flame, an electric heater, etc., there are conventionally those as shown in Patent Document 1 and Patent Document 2.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Patent Document 3
Patent Document 4
Summary of the Invention
Problems to be Solved by the Invention
[0004] Here, in the processing furnaces disclosed in Patent Document 1 and Patent Document 2, the microwaves generated from the microwave generator are guided into the furnace by a metal waveguide. However, as disclosed in Patent Document 3 and Patent Document 4, there are problems that the waveguide itself becomes an electrical resistor and generates heat, resulting in a decrease in microwave output, and that the thermal conductivity decreases between each component member of the processing furnace due to the thermal expansion of the waveguide.
[0005] Therefore, an object of the present invention is to provide a processing furnace with more excellent energy efficiency by causing microwaves to enter a retort without using a waveguide.
Means for Solving the Problems
[0006] The present invention relates to a processing furnace that heats and processes an object to be processed with microwaves, and a retort into which the object to be processed is carried, and an outer shell portion configured to surround the retort, and a microwave generator is provided in the outer shell portion, and holes are formed in the retort for the microwaves generated from the microwave generator to enter the retort.
[0007] According to the above configuration, microwaves from the microwave generator provided in the outer shell portion enter the retort through the holes formed in the retort. Therefore, it is not necessary to guide the microwaves into the retort by a waveguide, and it is possible to suppress a decrease in output due to heat generation of the waveguide itself and the influence on each component due to thermal expansion of the waveguide.
Effect of the Invention
[0008] According to the present invention, it is possible to provide a processing furnace with more excellent energy efficiency by allowing microwaves to enter the retort without using a waveguide.
Brief Description of the Drawings
[0009]
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Figure 11
Mode for Carrying Out the Invention
[0010] FIG. 1 is a schematic view of a treatment furnace 10 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. As shown in FIGS. 1 and 2, the treatment furnace 10 is a treatment furnace that heats and treats an object to be treated S with microwaves, and includes a feeder 1 into which the object to be treated S is introduced, a retort 2 into which the object to be treated S is gradually carried by the feeder 1, an outer shell portion 3 configured to surround the retort 2, a recovery container 4 for recovering the object to be treated S treated in the retort 2, and an exhaust port 5 for discharging the gas generated by the treatment of the object to be treated S to the outside.
[0011] The outer shell portion 3 has a cylindrical shape with a circular cross-section, and a microwave generator 6 for generating microwaves is provided on the upper wall portion 31 of the outer shell portion 3. In this embodiment, a plurality of microwave generators 6 are provided at intervals with respect to the axial direction X of the retort 2. The outer shell portion 3 is made of a metal having a function of an electromagnetic shield for preventing the entry and leakage of electromagnetic waves, for example, rolled steel (such as SS material). Note that the outer shell portion 3 may have a rectangular tube shape with a rectangular cross-section. The upper wall portion 31 may be a wall portion located above the vertical center of the outer shell portion 3, and may be horizontal or inclined.
[0012] The outer shell portion 3 is provided with a protective member 7 that protects the microwave generator 6 from the gas generated by processing the object to be processed S. The protective member 7 is attached to the upper wall portion 31 of the outer shell portion 3 so as to cover the entire microwave generator 6, and is made of a material that easily transmits microwaves but does not allow the gas to pass through, for example, alumina, quartz, or Teflon (registered trademark).
[0013] The retort 2 has a cylindrical shape with a circular cross-section, and one or more holes 8 are formed in the upper wall portion 21 of the retort 2 for the microwaves generated by the microwave generator 6 to enter the retort 2. The retort 2 is made of a metal with high heat resistance and corrosion resistance, such as stainless steel (SUS310S, etc.), in consideration of processing the object to be processed S. The retort 2 and the outer shell portion 3 are arranged concentrically.
[0014] The retort 2 receives the object to be processed S supplied from the feeder 1 through the inlet 22, heat-treats the object to be processed S in the retort 2, and then discharges the object to be processed S from the outlet 23. The object to be processed S discharged from the retort 2 is collected by a collection container 4 provided below the outlet 23. An exhaust port 5 for discharging the gas generated by the heat treatment of the object to be processed S to the outside is provided above the outlet 23.
[0015] The retort 2 is slightly inclined downward from the inlet 22 toward the outlet 23, and is configured to be swingable left and right with respect to the axial direction X of the retort 2. Therefore, the object to be processed S received from the inlet 22 is automatically conveyed through the inside of the retort 2 to the outlet 23 by the swinging of the retort 2.
[0016] Figure 3 is a top view of the vicinity of the hole 8 of the retort 2. As shown in FIGS. 1 to 3, a plurality of holes 8 formed in the upper wall portion 21 of the retort 2 are provided at intervals with respect to the axial direction X of the retort 2. The hole 8 is disposed directly below the microwave generator 6. If the length L1 of the hole 8 in the axial direction X of the retort 2 is longer than the length L2 of the microwave generator 6, heat in the retort 2 easily escapes upward. On the other hand, if it is shorter than the length L2, microwaves do not sufficiently enter the retort 2, resulting in poor thermal efficiency. Therefore, it is preferable that the length L1 of the hole 8 in the axial direction X of the retort 2 coincides with the length L2 of the microwave generator 6. Further, the hole 8 as viewed from above the retort 2 has a rectangular shape.
[0017] Figure 4 is an enlarged view of the hole 8 of FIG. 2. As shown in FIG. 4, the corner portion 8a of the hole 8 is chamfered. Further, the entire surface of the hole 8 may be formed of a curved surface. A protruding portion 812 protruding inward is formed on the side wall surface 81 forming the hole 8. Also, in a cross section perpendicular to the axial direction of the retort 2 X the hole 8 is open so as to have an angle of up to ±θa degrees from the vertically upward direction Y. For example, θa is 30 degrees to 45 degrees.
[0018] (Treatment of the object to be treated S by the treatment furnace 10) The object to be treated S is first put into the feeder 1. The object to be treated S put into the feeder 1 is gradually carried into the cylindrical retort 2 by the feeder 1.
[0019] When the object to be treated S is carried into the retort 2, the retort 2 swings circumferentially to the left and right with respect to the axial direction X of the retort 2, and the microwave generator 6 provided on the upper wall portion 31 of the outer shell portion 3 operates. Microwaves generated from the microwave generator 6 enter the retort 2 through the hole 8 formed in the upper wall portion 21 of the retort 2. Then, the object to be treated S in the retort 2 is irradiated with microwaves and heated.
[0020] The retort 2 slopes slightly downward (about 1 to 2 degrees) from the inlet 22 toward the outlet 23. Further, due to the left - right oscillation of the retort 2, the object to be processed S in the retort 2 is uniformly heat - treated by microwaves while being agitated and is conveyed from the inlet 22 toward the outlet 23. Here, considering the angle of the left - right oscillation of the retort 2 from the vertically upward direction Y of the hole 8 up to a maximum of ±θa degrees, so that the object to be processed S is not discharged from the hole 8, for example, it is less than ±θa' degrees from ±θa degrees to the contact point P where the upper surface S' of the object to be processed S contacts the inner surface of the retort 2. However, when the protrusion 812 is provided as shown in FIG. 2, it can oscillate at a larger angle. Here, it is assumed that the upper surface S' of the object to be processed S is substantially horizontal, but the upper surface S' of the object to be processed S may be inclined.
[0021] The object to be processed S heat - treated in the retort 2 is discharged from the outlet 23 and collected in the collection container 4. Also, the gas generated by heat - treating the object to be processed S is discharged to the outside from the exhaust port 5 provided above the outlet 23. Since the microwave generator 6 is covered by the protective member 7, it is not exposed to the gas generated by heat - treating the object to be processed S.
[0022] According to the processing furnace 10 having the above - described configuration, the following effects can be exhibited.
[0023] (1) Since the microwaves from the microwave generator 6 provided in the outer shell portion 3 enter the retort 2 through the holes 8 formed in the retort 2, it is not necessary to guide the microwaves into the retort 2 by a waveguide, and it is possible to suppress the output reduction due to the heat generation of the waveguide itself and the influence on each component due to the thermal expansion of the waveguide.
[0024] (2) Since the corners 8a of the holes 8 are chamfered, it is possible to suppress the microwaves entering the retort 2 from the holes 8 from concentrating on the sharp portions of the holes 8 and overheating or sparking. The chamfering may be in the form of cutting off a general corner at 45 degrees, but chamfering with a curved surface as shown in FIG. 4 is preferable because the sharp portion disappears.
[0025] (3) The microwave generator 6 is provided on the inner surface of the upper wall portion 31 of the outer shell portion 3, the hole 8 is provided in the upper wall portion 21 of the retort 2, and the retort 2 is configured to swing at an angle such that the object to be processed S in the retort 2 is not discharged from the hole 8 to the outside of the retort 2. Therefore, the object to be processed S in the retort 2 can be stirred without discharging the object to be processed S from the hole 8, and a uniform heat treatment can be performed.
[0026] (4) Since a protruding portion 812 protruding inward is formed on the side wall surface 81 of the hole 8, it is possible to suppress the object to be processed S in the retort 2 from being discharged from the hole 8 to the outside of the retort 2.
[0027] (5) The retort 2 has a cylindrical shape. In a cross section perpendicular to the axial direction X of the retort 2, if the opening angle of the hole 8 is too small, microwaves are difficult to enter, and if the opening angle is too large, the swinging angle becomes small and the object to be processed S cannot be sufficiently stirred. Therefore, it is preferable to open the hole 8 at an angle of ±30 degrees to ±45 degrees from the vertically upward direction Y in order to improve the heating efficiency of the object to be processed S.
[0028] (Another embodiment) In the above embodiment, the hole 8 is widely opened at one location so as to have a maximum angle of ±θa degrees from the vertically upward direction Y, but a plurality of holes 8 may be provided in the circumferential direction of the upper wall portion 21 of the retort 2.
[0029] FIG. 5 is a schematic cross-sectional view of a processing furnace 10 according to another embodiment of the present invention, in which three circular holes 91 (91a, 91b, 91c) are formed in the circumferential direction of the upper wall portion 21 of the retort 2 in a top view. FIG. 6 is a top view of the vicinity of the hole 91 of the retort 2 in FIG. 5. Further, FIG. 7 is a schematic cross-sectional view of a processing furnace 10 according to another embodiment of the present invention, in which three substantially square holes 92 (92a, 92b, 92c) are formed in the circumferential direction of the upper wall portion 21 of the retort 2 in a top view. FIG. 8 is a top view of the vicinity of the hole 92 of the retort 2 in FIG. 7. FIGS. 5 and 7 only differ in the shapes of the holes 91 and 92 in a top view. In the other embodiments of FIGS. 5 and 7, the holes 91 and 92 are different from those in the above embodiment, and the other configurations are the same as those in the above embodiment. Therefore, in the description of the other embodiments, the same reference numerals are given to the same parts as those in the above embodiment, and the detailed description thereof is omitted.
[0030] As shown in FIGS. 5 and 7, a plurality of holes 91 and 92 are provided at intervals with respect to the axial direction X of the retort 2. The holes 91 and 92 are arranged directly below the microwave generator 6. If the length L1 of the holes 91 and 92 in the axial direction X of the retort 2 is longer than the length L2 of the microwave generator 6, the heat in the retort 2 easily escapes upward. On the other hand, if it is shorter than the length L2, the microwaves do not sufficiently enter the retort 2, resulting in poor thermal efficiency. Therefore, it is preferable that the length L1 of the holes 91 and 92 in the axial direction X of the retort 2 coincides with the length L2 of the microwave generator 6.
[0031] FIG. 9 is an enlarged view of the hole 91 in FIG. 5, and FIG. 10 is an enlarged view of the hole 92 in FIG. 7. The corners 91d and 92d of the holes 91 and 92 in FIGS. 9 and 10 are chamfered. The chamfering may have a general shape in which the corners are cut off at 45 degrees. However, as shown in FIGS. 9 and 10, chamfering with a curved surface is preferable because the sharp portions are eliminated and partial overheating and sparking are less likely to occur.
[0032] Also, in a cross-section perpendicular to the axial direction X of the retort 2, the holes 91 open at angles of up to +θb degrees (hole 91c) and up to -θb degrees (hole 91a) from the vertically upward direction Y, and the holes 92 open at angles of up to +θc degrees (hole 92c) and up to -θc degrees (hole 92a) from the vertically upward direction Y. θb and θc are the same as θa, for example, 30 degrees to 45 degrees. The angles of left and right swinging of the retort 2 are less than ±θb' degrees and ±θc' degrees from ±θb degrees and ±θc degrees, respectively, to the contact point P where the upper surface S' of the object to be processed S contacts the inner surface of the retort 2, as in the above-described embodiment. Also, as in the above-described embodiment, the upper surface S' may be inclined rather than substantially horizontal.
[0033] According to the configuration of the above-described another embodiment, compared with the case of the above-described embodiment, the circumferential opening areas of the holes 91 and 92 are smaller than the circumferential opening area of the hole 8, but the heat radiation from the holes 91 and 92 into the retort 2 is reduced, and the area where the retort 2 is connected at the upper part is increased, so that the thermal deformation of the retort 2 can be suppressed.
[0034] FIG. 11 is a schematic cross-sectional view of a processing furnace 10 according to still another embodiment of the present invention, in which three circular holes 91 (91a, 91b, 91c) are formed in the circumferential direction of the upper wall portion 21 of the retort 2 in a top view, and a plurality of microwave generators 6 are provided in the circumferential direction of the upper wall portion 31. The microwave generators 6 may be provided in plurality in the circumferential direction of the upper wall portion 31 so as to face the holes 91. As a result, the entry of microwaves into the retort 2 can be improved. Note that the shape of the holes 91 may be substantially square.
[0035] Summarizing the present invention and the embodiments, it is as follows.
[0036] (1) One embodiment of the present invention is a processing furnace for heating and processing an object to be processed with microwaves, a retort into which the object to be processed is carried, and an outer shell portion configured to surround the retort, wherein a microwave generator is provided in the outer shell portion, The retort is formed with a hole for the microwave generated by the microwave generator to enter the retort.
[0037] According to the configuration (1), since the microwave from the microwave generator provided in the outer shell part enters the retort through the hole formed in the retort, it is not necessary to guide the microwave into the retort by a waveguide, and it is possible to suppress a decrease in output due to heat generation of the waveguide itself and the influence on each component due to thermal expansion of the waveguide.
[0038] (2) In the configuration (1), the corners of the hole are chamfered.
[0039] According to the configuration (2), by chamfering the corners of the hole, it is possible to suppress the microwave entering the retort from the hole from concentrating on the sharp part of the hole and overheating or sparking.
[0040] (3) In the configuration (1) or (2), the microwave generator is provided on the upper wall part or the inclined part of the outer shell part, the hole is provided on the upper wall part of the retort, the retort is configured to swing at an angle at which the object to be processed in the retort is not discharged from the retort through the hole.
[0041] According to the configuration (3), it is possible to stir the object to be processed in the retort without discharging the object to be processed from the hole and perform a uniform heat treatment.
[0042] (4) In any one of the configurations (1) to (3), a protruding portion protruding inward is formed on the side wall surface of the hole.
[0043] According to the configuration (4), by providing a protruding portion protruding inward on the side wall surface of the hole, it is possible to suppress the object to be processed in the retort from being discharged from the retort through the hole, and the swinging angle can be increased to perform better stirring.
[0044] (5) In any one of the above configurations (1) to (4), the retort has a cylindrical shape, In a cross-section perpendicular to the axial direction of the retort, the holes are opened at an angle of ±30 degrees to ±45 degrees from the vertically upward direction.
[0045] According to the above configuration (5), since the holes are opened at an angle of ±30 degrees to ±45 degrees from the vertically upward direction, microwaves can easily enter the retort, the object to be processed can be well stirred, and the heating efficiency of the object to be processed can be improved.
[0046] Without departing from the spirit and scope of the present invention described in the claims, various modifications and changes can also be made.
Industrial Applicability
[0047] In the present invention, by allowing microwaves to enter the retort without using a waveguide, a processing furnace with better energy efficiency can be provided, so it has great industrial utility value.
Explanation of Reference Numerals
[0048] 1 Feeder 2 Retort 21 Upper Wall Portion 22 Inlet 23 Outlet 3 Outer Shell Portion 31 Upper Wall Portion 4 Recovery Container 5 Exhaust Port 6 Microwave Generator 7 Protective Member 8 Hole 8a Corner 81 Side Wall Surface 812 Protrusion 91 Hole 91a Hole 91b Hole 91c Hole 91d Corner 92 Hole 92a Hole 92b Hole 92c Hole 92d Corner 10 Processing furnace X-direction length of the L1 hole X-direction length of the L2 microwave generator P Contact point S Workpiece S’ Upper surface of the workpiece X-axis direction Y Vertically upward direction
Claims
1. A processing furnace that heats and processes an object to be processed with microwaves, comprising: a retort into which the object to be processed is carried; an outer shell portion configured to surround the retort; a microwave generator is provided on the inner surface of the outer shell portion; a hole is formed in the retort for the microwave generated from the microwave generator to enter the retort, the processing furnace.
2. The processing furnace according to claim 1, wherein the corners of the hole are chamfered.
3. The microwave generator is provided on the inner surface of the upper wall portion of the outer shell portion; the hole is provided in the upper wall portion of the retort; the retort is configured to swing at an angle such that the object to be processed in the retort is not discharged from the hole to the outside of the retort, the processing furnace according to claim 1.
4. The processing furnace according to claim 1, wherein a protruding portion protruding inward is formed on the side wall surface of the hole.
5. The retort has a cylindrical shape; in a cross section perpendicular to the axial direction of the retort, the hole opens at an angle of ±30 degrees to ±45 degrees from the vertically upward direction, the processing furnace according to any one of claims 1 to 4.
Citation Information
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