Intermittent heat treatment furnace

Abstract

The technical problem of the present invention is to suppress variations in the atmosphere in a furnace. This intermittent heat treatment furnace is provided with: a hearth; a furnace wall having a side wall and a top wall provided so as to surround the hearth, the furnace wall forming a furnace chamber inside together with the hearth; a heater for heating the furnace chamber; a hollow cylindrical first exhaust pipe inserted into the furnace chamber in the vertical direction from the hearth or the top wall; a second exhaust pipe having a larger diameter than the first exhaust pipe, the first exhaust pipe being inserted through the inside thereof, and being shorter than the insertion length of the first exhaust pipe into the furnace chamber; and a pair of exhaust flow rate adjustment blocks capable of closing at least a part of a central opening, which is a furnace outside opening of a first exhaust flow path formed inside the first exhaust pipe, and at least a part of a first outer peripheral opening, which is a furnace outside opening of a second exhaust flow path formed between the first exhaust pipe and the second exhaust pipe. A gap having a variable width is formed between the first exhaust pipe and the second exhaust pipe across an exhaust pipe center axis, which is the center axis of the first exhaust pipe and the second exhaust pipe.

Description

Technical Field

[0001] The present disclosure relates to a batch-type heat treatment furnace for heat treatment processes and the like. Background Art

[0002] In the manufacturing processes of various products such as ceramic electronic components, a heat treatment furnace for heat-treating components and semi-products is used. As the heat treatment furnace, a batch-type heat treatment furnace and a continuous-type heat treatment furnace can be cited. The batch-type heat treatment furnace can be applied to, for example, cases where the number of workpieces to be heat-treated under the same conditions is small, or cases where it is necessary to heat-treat workpieces divided into multiple groups under different multiple conditions.

[0003] On the other hand, due to the high precision of electronic components to be heat-treated and the improvement of required performance in recent years, there is an expectation to more strictly manage processing conditions such as temperature, pressure, and atmosphere during heat treatment. To strictly manage the heat treatment conditions in a batch-type heat treatment furnace or the like, it is effective to suppress the deviation of the temperature distribution in the furnace. As an existing technique for suppressing the deviation of the temperature distribution in the furnace of a batch-type heat treatment furnace, for example, when gas is supplied from a gas supply pipe into the furnace, the gas ejected from the gas supply pipe is heated by the heat of a heater and dispersed in the furnace (see Patent Document 1 and the like).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 4385213 Specification Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] However, there is a problem in the existing batch-type heat treatment furnace that the deviation of the temperature distribution in the furnace cannot be sufficiently suppressed due to the deviation of the position of the gas discharge port in the furnace or the like.

[0009] Technical Solution for Solving the Problem

[0010] To solve the above problems, the present disclosure provides a batch-type heat treatment furnace having:

[0011] A furnace bed;

[0012] A furnace wall having side walls and a top wall provided to surround the furnace bed, and together with the furnace bed, forming a furnace chamber inside;

[0013] A heater for heating the furnace chamber;

[0014] A hollow cylindrical first exhaust pipe inserted into the furnace chamber in the vertical direction from the furnace bed or the top wall;

[0015] A second exhaust pipe, which has a larger diameter than the first exhaust pipe, the first exhaust pipe being inserted through its interior and having a shorter insertion length into the furnace chamber than the first exhaust pipe; and

[0016] A pair of exhaust gas flow adjustment blocks, which can close at least a part of the central opening and at least a part of the first outer peripheral opening, and form a variable-width gap therebetween across the exhaust pipe central axis that is the central axis of the first exhaust pipe and the second exhaust pipe. The central opening is the furnace-side opening of the first exhaust gas flow path formed inside the first exhaust pipe, and the first outer peripheral opening is the furnace-side opening of the second exhaust gas flow path formed between the first exhaust pipe and the second exhaust pipe.

[0017] The batch-type heat treatment furnace of the present disclosure has a double-pipe structure. Through the exhaust structure composed of the first and second exhaust pipes inserted with different lengths in the vertical direction, the deviation of the inlet position of the exhaust gas flow path can be reduced. In addition, through the exhaust gas flow adjustment blocks that form a gap and close at least a part of the furnace-side openings of the exhaust pipes, the balance of each exhaust gas flow path can be maintained with a simple structure and the exhaust gas flow rates from the first and second exhaust gas flow paths can be adjusted. Such a batch-type heat treatment furnace can reduce the temperature and pressure deviations in the furnace chamber. In addition, the exhaust gas flow adjustment blocks also have the following effects: by reducing the exhaust gas flow rate, the combustion of coal and the like contained in the gas is promoted, so that the coal and the like contained in the discharged gas are reduced, and the pollution of the common exhaust gas flow path of the building and the like is prevented.

[0018] In addition, for example, it may also be that irregularities are formed on the respective opposing surfaces of the pair of exhaust gas flow adjustment blocks across the gap.

[0019] By forming irregularities on the opposing surfaces of the exhaust gas flow adjustment blocks, the change in the ratio of the opening areas of the central opening and the first outer peripheral opening accompanying the change in the width of the gap can be adjusted.

[0020] In addition, for example, it may also be that the irregularities are formed on the opposing surfaces in such a way that a first width is narrower than a second width. The first width is the width of the gap at a first distance from the exhaust pipe central axis, and the second width is the width of the gap at a second distance longer than the first distance from the exhaust pipe central axis.

[0021] With such an irregular shape on the opposing surfaces of the exhaust gas flow adjustment blocks, even when the width of the gap is changed, the ratio of the opening areas of the central opening and the first outer peripheral opening can be brought within a specified range.

[0022] Alternatively, for example, it may also be that the batch-type heat treatment furnace of the present disclosure has: a block holding member that holds a pair of the exhaust gas flow rate adjustment blocks so as to be slidable along the relative direction of the pair of the exhaust gas flow rate adjustment blocks.

[0023] The batch-type heat treatment furnace having such a block holding member can easily and highly accurately adjust the gap width, so that the adjustment of the exhaust flow rate is easy and the maintainability is excellent.

[0024] Alternatively, for example, it may also be that it further has: a third exhaust pipe that is larger in diameter than the second exhaust pipe, and the first exhaust pipe and the second exhaust pipe are inserted through its interior, and has a shorter insertion length into the furnace chamber than the second exhaust pipe.

[0025] A pair of the exhaust gas flow rate adjustment blocks can close at least a part of a second outer peripheral opening, which is an opening on the furnace outer side of a third exhaust gas flow path formed between the second exhaust pipe and the third exhaust pipe.

[0026] In such a batch-type heat treatment furnace, through a three-layer exhaust structure constituted by the first to third exhaust pipes inserted with different lengths in the vertical direction, the deviation of the position of the inlet of the exhaust gas flow path can be further reduced. In addition, the exhaust gas flow rate adjustment blocks can maintain balance with a simple structure and centrally adjust the exhaust gas flow rates from the first to third exhaust gas flow paths.

[0027] Alternatively, for example, it may also be that it has: a plurality of gas supply pipes that are provided with openings in the furnace chamber and supply gas to the furnace chamber via the side wall.

[0028] The plurality of gas supply pipes include: at least two gas supply pipes having the same distance from the opening of each gas supply pipe to a first opening, which is an opening in the furnace of the first exhaust gas flow path.

[0029] The plurality of gas supply pipes include: at least two gas supply pipes having the same distance from the opening of each gas supply pipe to a second opening, which is an opening in the furnace of the second exhaust gas flow path.

[0030] In such a batch-type heat treatment furnace, since there are at least two gas supply pipes having the same distance from the first and second openings with respect to each of the first and second exhaust gas flow paths to the first to third openings of the first to third exhaust gas flow paths, the deviation of the temperature distribution and the pressure distribution caused by the different distances from the gas supply positions can be reduced.

[0031] Alternatively, for example, it may also be that the furnace bed rotates about a main rotation axis extending in the vertical direction.

[0032] It may also be that the center axis of the exhaust pipe is substantially aligned with the extension line of the main rotation axis.

[0033] This batch-type heat treatment furnace can reduce the deviation of heat treatment conditions caused by different positions in the rotation direction of the workpiece, in particular, by rotating the furnace bed on which the workpiece is placed. In addition, in the batch-type heat treatment furnace, even if the workpiece or the furnace bed rotates, by arranging the furnace inner openings of the discharge flow path having the exhaust pipe central axis on the extension line of the main rotation axis at two or more different heights, smooth gas discharge and adjustment of the discharge amount with good balance can be achieved.

[0034] In addition, for example, the furnace bed may have a sub-furnace bed that revolves around the main rotation axis and rotates around a sub-rotation axis that is parallel to the main rotation axis and at a specified distance from the main rotation axis.

[0035] This batch-type heat treatment furnace can reduce the deviation of heat treatment conditions caused by different distances of the workpiece from the side wall or the central part of the furnace chamber, in particular. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a conceptual diagram showing the batch-type heat treatment furnace according to the first embodiment of the present disclosure.

[0037] Figure 2 is showing Figure 1 the flow of gas in the batch-type heat treatment furnace shown.

[0038] Figure 3 is showing Figure 1 a partial cross-sectional view of the periphery of the exhaust flow rate adjustment block in the batch-type heat treatment furnace shown.

[0039] Figure 4 is showing from above Figure 2 the state of the periphery of the exhaust flow rate adjustment block shown.

[0040] Figure 5 is showing Figure 4 the variable-width slit of the exhaust flow rate adjustment block shown.

[0041] Figure 6 is a conceptual diagram showing the flow of gas in the batch-type heat treatment furnace according to the second embodiment of the present disclosure.

[0042] Figure 7 is showing from above Figure 6 the state of the periphery of the exhaust flow rate adjustment block in the batch-type heat treatment furnace shown.

[0043] Figure 8 is showing Figure 7 the variable-width slit of the exhaust flow rate adjustment block shown.

[0044] Figure 9 This is a conceptual diagram showing the flow of gas in a batch-type heat treatment furnace according to the third embodiment of the present disclosure.

[0045] Explanation of reference numerals

[0046] 10, 110, 210... Batch-type heat treatment furnace

[0047] 11, 111... Furnace main body part

[0048] 12, 212... Hearth

[0049] 13... Main hearth

[0050] 13a... Central position

[0051] 14, 15... Sub-hearth

[0052] C1... Main rotating shaft

[0053] C2, C3... Sub-rotating shafts

[0054] 16... Furnace wall

[0055] 17... Side wall

[0056] 18... Top wall

[0057] 20, 220... Furnace chamber

[0058] 21, 221... Central part

[0059] D1... Up and down direction

[0060] 24... Heater

[0061] 24a... Upper end

[0062] 24b...... Lower end

[0063] 30... Multiple gas supply pipes

[0064] 31a, 31b... First gas supply pipe

[0065] 32a, 32b... Second gas supply pipe

[0066] 33a, 33b... Third gas supply pipe

[0067] 31aa, 31ba, 32aa, 32ba, 33aa, 33ba... Openings

[0068] 51, 251... First exhaust pipe

[0069] 52, 152, 252... Second exhaust pipes

[0070] 153, 253... Third exhaust pipes

[0071] Insertion lengths of L1, L2, L3…

[0072] First exhaust gas flow paths of 61, 261…

[0073] First openings of 61a, 261a…

[0074] Central openings of 61b, 261b…

[0075] Second exhaust gas flow paths of 62, 162, 262…

[0076] Second openings of 62a, 162a, 262a…

[0077] First outer peripheral openings of 62b, 162b, 262b…

[0078] Third exhaust gas flow paths of 163, 263…

[0079] Third openings of 163a, 263a…

[0080] Second outer peripheral openings of 163b, 263b…

[0081] Retention frame of 19…

[0082] Retention rod of 55…

[0083] Exhaust gas volume adjustment mechanisms of 70, 170…

[0084] Exhaust gas volume adjustment blocks of 71, 72, 171, 172…

[0085] Opposite faces of 71a, 72a, 171a, 172a…

[0086] Unevenness of 171b, 172b…

[0087] Slits of 73, 173…

[0088] First distance of LS1…

[0089] First width of W1…

[0090] Second distance of LS2…

[0091] Second width of W2…

[0092] Block retention member of 74…

[0093] Guide member of 75…

[0094] Fixing fitting of 76…

[0095] Carrier of 82…

[0096] Arrows of 91, 92…

[0097] 95…Exhaust chamber

[0098] D1…Vertical direction

[0099] 96…Exhaust pipe Detailed implementation mode

[0100] First Embodiment

[0101] Figure 1 It is a conceptual diagram showing the batch-type heat treatment furnace 10 of the first embodiment of the present disclosure. The batch-type heat treatment furnace 10 has a furnace bed 12, furnace walls 16, etc. The furnace walls 16 have side walls 17 and a top wall 18 arranged to surround the furnace bed 12. The furnace walls 16 and the furnace bed 12 together form a furnace chamber 20 inside. Figure 1 The shown furnace walls 16 have a generally cylindrical outer shape that is open at the bottom, and the furnace bed 12 is arranged to block the bottom opening of the furnace walls 16.

[0102] The furnace bed 12 has a generally disk-shaped main furnace bed 13 that blocks the bottom opening of the furnace walls 16, and sub-furnace beds 14 and 15 provided on the main furnace bed 13. In Figure 1 only two sub-furnace beds 14 and 15 are shown, but the furnace bed 12 has two other sub-furnace beds in addition to the two sub-furnace beds 14 and 15, and has a total of four sub-furnace beds 14 and 15. The four sub-furnace beds 14 and 15 are arranged at a specified interval (every 90 degrees in the embodiment) at substantially equal intervals so as to surround the central position 13a of the main furnace bed 13 when viewed from above. The distances between the center positions 13a of each sub-furnace bed 14 and 15 and the main furnace bed 13 are substantially the same.

[0103] In the batch-type heat treatment furnace 10, the furnace bed 12 rotates (self-rotates) about a main rotation axis C1 extending in the vertical direction as shown by the arrow 91. The main rotation axis C1 about which the furnace bed 12 rotates passes through the center position 13a of the main furnace bed 13. In addition, the central axis of the first exhaust pipe 51 and the second exhaust pipe 52 described later, that is, the exhaust pipe central axis C4, is substantially coincident with the extension line of the main rotation axis C1. The furnace bed 12, for example, transmits a rotational force from a motor (not shown) to the main furnace bed 13, and the main furnace bed 13 rotates, so that the entire furnace bed 12 including the sub-furnace beds 14 and 15 rotates. In such a batch-type heat treatment furnace 110, by rotating the furnace bed 12 on which workpieces and the like are placed, even if there are deviations in the temperature distribution around the exhaust pipe central axis C4 and the main rotation axis C1 in the furnace chamber 20, for example, it is possible to suppress deviations in the heat treatment conditions of each workpiece.

[0104] In addition, the sub-hearths 14 and 15 in the hearth 12 rotate about the sub-rotation axes C2 and C3 as their own rotation axes as shown by the arrow 92. That is, the sub-hearth 14 rotates about the sub-rotation axis C2 which is parallel to the main rotation axis C1 and at a specified distance from the main rotation axis C1 as its own rotation axis. In addition, the sub-hearth 15 rotates about the sub-rotation axis C3 which is parallel to the main rotation axis C1 and at a specified distance from the main rotation axis C1 as its own rotation axis. In addition, the distance from the main rotation axis C1 to the sub-rotation axis C2 and the distance from the main rotation axis C1 to the sub-rotation axis C3 are substantially the same.

[0105] In Figure 1 In the batch-type heat treatment furnace 10 shown, the sub-hearths 14 and 15 and the setter 82 placed on the sub-hearths 14 and 15 revolve about the main rotation axis C1 and rotate about the sub-rotation axes C2 and C3 as their own rotation axes. Such a batch-type heat treatment furnace 10 can particularly reduce the deviation of the heat treatment conditions caused by the different distances of the workpieces from the side wall 17 or the central part 21 of the furnace chamber 20.

[0106] However, as the hearth 12 of the batch-type heat treatment furnace 10, it is not limited to Figure 1 the hearth having the main hearth 13 and the sub-hearths 14 and 15 as shown. For example, it may also be a hearth having only the main hearth 13, or a hearth in which any one or both of the main hearth 13 and the sub-hearths 14 and 15 do not rotate. In addition, regarding the number and arrangement of the sub-hearths 14 and 15 of the hearth 12, Figure 1 what is shown is only an example and is not limited to the example shown in the embodiment.

[0107] As Figure 1 shown, a plurality of setters (also called saggers) 82 are provided on the hearth 12 and stacked in the vertical direction D1 in a substantially horizontal posture. The setters 82 are arranged on the hearth 12 in a state of being stacked on each of the sub-hearths 14 and 15. A placement portion for placing the workpieces, which are the objects of heat treatment of the batch-type heat treatment furnace 10, is formed on the setter 82. As Figure 1 shown, by stacking and arranging a plurality of setters 82 for each of the sub-hearths 14 and 15, a plurality of workpieces can be arranged in the furnace chamber 20 while appropriately separating the workpieces from each other and suppressing the deviation of the heat treatment conditions of each workpiece.

[0108] As the material of the setter 82, for example, ceramics containing alumina, magnesia, zirconia, etc. which are chemically stable even at high temperatures can be cited, but there is no particular limitation. The hearth 12 and the furnace wall 16 can also be made of materials having excellent fire resistance and heat insulation properties such as ceramics.

[0109] As Figure 1As shown, the batch-type heat treatment furnace 10 includes: a plurality of gas supply pipes 30, a heater 24, a first exhaust pipe 51, a second exhaust pipe 52, etc. The heater 24 is arranged to surround the central portion 21 of the furnace chamber 20 along the side wall 17 and heat the furnace chamber 20.

[0110] As Figure 1 shown, the heater 24 is arranged in the vertical direction D1 along the side wall 17. The upper end 24a of the heater 24 is at the same height as the carrier 82 stacked on the furnace bed 12 or higher than the height of the carrier 82. In addition, the lower end 24b of the heater 24 is at the same height as the installation surface of the carrier 82 on each sub-furnace bed 14, 15 or lower than the installation surface of the carrier 82. Such an arrangement of the heater 24 is preferable from the viewpoint of suppressing temperature deviation in the furnace chamber 20, particularly in the area where the workpiece is arranged.

[0111] The heater 24 is not particularly limited, and examples thereof include heaters having metal heating elements such as Ni-Cr series, Fe-Cr-Al series, molybdenum, tungsten, etc., or non-metal heating elements such as silicon carbide, graphite, zirconia, etc.

[0112] As Figure 1 shown, the batch-type heat treatment furnace 10 has a plurality of gas supply pipes 30. The plurality of gas supply pipes 30 have openings in the furnace chamber 20 and supply gas to the furnace chamber 20 through the side wall 17. As Figure 1 shown, the plurality of gas supply pipes 30 are composed of a first gas supply pipe 31a, 31b, a second gas supply pipe 32a, 32b, and a third gas supply pipe 33a, 33b. The openings 31aa, 31ba of the first gas supply pipe 31a, 31b, the openings 32aa, 32ba of the second gas supply pipe 32a, 32b, and the openings 33aa, 33ba of the third gas supply pipe 33a, 33b are arranged near the side wall 17 closer than the carrier 82 and the sub-furnace beds 14, 15. The first gas supply pipe 31a, 31b, the second gas supply pipe 32a, 32b, and the third gas supply pipe 33a, 33b discharge gas into the furnace chamber 20 from their respective openings 31aa, 31ba, 32aa, 32ba, 33aa, 33ba.

[0113] The positions of the openings 31aa, 31ba of the first gas supply pipe 31a, 31b in the vertical direction D1 of the furnace chamber 20 are different from the openings 32aa, 32ba, 33aa, 33ba of the second gas supply pipe 32a, 32b and the third gas supply pipe 33a, 33b. That is, for the first gas supply pipe 31a, 31b, their openings 31aa, 31ba are arranged lower in the furnace chamber 20 than the other openings 32aa, 32ba, 33aa, 33ba.

[0114] On the other hand, towards Figure 1 the right side, the opening 31aa of the first gas supply pipe 31a and towardsFigure 1 The openings 31ba of the first gas supply pipes 31b on the left side are in the same position in the vertical direction D1 of the furnace chamber 20. However, the directions of the openings 31aa of the first gas supply pipes 31a and the openings 31ba of the first gas supply pipes 31b with respect to the central portion 21 of the furnace chamber 20 are different. More specifically, the openings 31aa of the first gas supply pipes 31a and the openings 31ba of the first gas supply pipes 31b are symmetrically arranged with respect to the central portion 21 of the furnace chamber 20.

[0115] In addition, the positions of the openings 32aa, 32ab of the second gas supply pipes 32a, 32b in the vertical direction D1 of the furnace chamber 20 are different from the openings 31aa, 31ba, 33aa, 33ba of the first gas supply pipes 31a, 31b and the third gas supply pipes 33a, 33b. That is, the openings 32aa, 32ba of the second gas supply pipes 32a, 32b are arranged in the furnace chamber 20 above the openings 31aa, 31ba of the first gas supply pipes 31b and below the openings 33aa, 33ba of the third gas supply pipes 33a, 33b.

[0116] On the other hand, towards Figure 1 The opening 32aa of the second gas supply pipe 32a on the right side and towards Figure 1 The opening 32ba of the second gas supply pipe 32b on the left side are in the same position in the vertical direction D1 of the furnace chamber 20. However, the directions of the opening 32aa of the second gas supply pipe 32a and the opening 32ba of the second gas supply pipe 32b with respect to the central portion 21 of the furnace chamber 20 are different. More specifically, the opening 32aa of the second gas supply pipe 32a and the opening 32ba of the second gas supply pipe 32b are symmetrically arranged with respect to the central portion 21 of the furnace chamber 20.

[0117] In addition, the positions of the openings 33aa, 33ba of the third gas supply pipes 33a, 33b in the vertical direction D1 of the furnace chamber 20 are different from the openings 31aa, 31ba, 32aa, 32ba of the first gas supply pipes 31a, 31b and the second gas supply pipes 32a, 32b. That is, the third gas supply pipes 33a, 33b, with their openings 33aa, 33ba, are arranged in the furnace chamber 20 above the other openings 31aa, 31ba, 32aa, 32ba.

[0118] On the other hand, towards Figure 1 The opening 33aa of the third gas supply pipe 33a on the right side and towards Figure 1The openings 33aa of the third gas supply pipe 33a and the openings 33ba of the third gas supply pipe 33b on the left side are at the same position in the vertical direction D1 of the furnace chamber 20. However, the directions of the openings 33aa of the third gas supply pipe 33a and the openings 33ba of the third gas supply pipe 33b with respect to the central portion 21 of the furnace chamber 20 are different. More specifically, the openings 33aa of the third gas supply pipe 33a and the openings 33ba of the third gas supply pipe 33b are symmetrically arranged with the central portion 21 of the furnace chamber 20 interposed therebetween.

[0119] The gas supplied from the plurality of gas supply pipes 30 to the furnace chamber 20 is not particularly limited, and examples thereof include inert gases such as nitrogen and helium, reducing gases such as hydrogen, or air.

[0120] As Figure 1 As shown, the batch heat treatment furnace 10 includes a first exhaust pipe 51 and a second exhaust pipe 52 inserted into the furnace chamber 20 from the top wall 18. The first exhaust pipe 51 and the second exhaust pipe 52 are inserted in the vertical direction D1 so as to pass through the central portion 21 of the furnace chamber 20 when the furnace chamber 20 is viewed from above. The first exhaust pipe 51 and the second exhaust pipe 52 are hollow cylindrical, and more specifically, are bottomless cylindrical shapes. However, the shapes of the first exhaust pipe 51 and the second exhaust pipe 52 are not limited to the cylindrical shape, and may be polygonal cylindrical shapes or other hollow cylindrical shapes.

[0121] The first exhaust pipe 51 and the second exhaust pipe 52 are arranged in a nested manner in the radial direction with their central axes aligned. As will be described later, the exhaust gas flow paths of the batch heat treatment furnace 10, that is, the first exhaust gas flow path 61 and the second exhaust gas flow path 62, are formed by these first and second exhaust pipes 51 and 52. Figure 2 It represents Figure 1 A conceptual diagram of the gas flow in the batch heat treatment furnace 10 shown. In Figure 2 In, Figure 1 The furnace bed 12 and the carrier 82 shown are omitted from the illustration.

[0122] As Figure 2 As shown, the diameter of the first exhaust pipe 51 is smaller than that of the second exhaust pipe 52 and is arranged inside. In addition, the first exhaust pipe 51 is longer than the second exhaust pipe 52, and the insertion length L1 of the first exhaust pipe 51 into the furnace chamber 20 is longer than the insertion length L2 of the second exhaust pipe 52 into the furnace chamber 20.

[0123] The diameter of the second exhaust pipe 52 is larger than that of the first exhaust pipe 51. The first exhaust pipe 51 is inserted through the inside of the second exhaust pipe 52. The second exhaust pipe 52 has a shorter insertion length into the furnace chamber 20 than the first exhaust pipe 51. As Figure 2 As shown, the insertion length L2 of the second exhaust pipe 52 into the furnace chamber 20 is shorter than the insertion length L1 of the first exhaust pipe 51 into the furnace chamber 20.

[0124] AsFigure 2 As shown, an exhaust gas flow path of the batch heat treatment furnace 10 is formed by an exhaust pipe having a double-layer structure constituted by the first and second exhaust pipes 51 and 52. That is, a first exhaust gas flow path 61 is formed inside the first exhaust pipe 51, and a furnace interior opening of the first exhaust gas flow path 61, i.e., a first opening 61a, is located below a furnace interior opening of another flow path, i.e., a second exhaust gas flow path 62, i.e., a second opening 62a.

[0125] The opening shape of the first opening 61a is circular (for example, refer to Figure 8 ), and it is disposed at the center portion 21 of the furnace chamber 20 when viewed from above. Therefore, the distance from the opening 31aa of the first supply pipe 31a to the first opening 61a is equal to the distance from the opening 31ba of the first supply pipe 31b to the first opening 61a. The same applies to the opening 32aa of the second supply pipe 32a and the opening 32ba of the second supply pipe 32b, and the opening 33aa of the third supply pipe 33a and the opening 33ba of the third supply pipe 33b. The distances to the first opening 61a are equal.

[0126] In addition, as Figure 2 shown, a second exhaust gas flow path 62 is formed between the first exhaust pipe 51 and the second exhaust pipe 52, and a furnace interior opening of the second exhaust gas flow path 62, i.e., a second opening 62a, is located above the first opening 61a of the first exhaust gas flow path 61.

[0127] The opening shape of the second opening 62a is a circular ring shape (for example, refer to Figure 4 ), and it is disposed at the center portion 21 of the furnace chamber 20 when viewed from above. Therefore, the distance from the opening 31aa of the first supply pipe 31a to the second opening 62a is equal to the distance from the opening 31ba of the first supply pipe 31b to the second opening 62a. The same applies to the opening 32aa of the second supply pipe 32a and the opening 32ba of the second supply pipe 32b, and the opening 33aa of the third supply pipe 33a and the opening 33ba of the third supply pipe 33b. The distances to the second opening 62a are equal.

[0128] One end portions of the first and second exhaust pipes 51 and 52 are located in the furnace chamber 20, but the other end portions of the first and second exhaust pipes 51 and 52 are located above the top wall 18 and are led out of the furnace chamber 20. A furnace exterior opening of the first exhaust gas flow path 61, i.e., a central opening 61b, and a furnace exterior opening of the second exhaust gas flow path 62, i.e., a first outer peripheral opening 62b, are aligned in the vertical direction D1 and are arranged in a concentric circle shape.

[0129] Figure 2 The thick arrows shown indicate the flow of gas in the furnace chamber 20. As Figure 2As shown, in the batch-type heat treatment furnace 10, gas is discharged from the first opening 61a and the second opening 62a disposed at different heights in the central portion 21 of the furnace chamber 20. In such a batch-type heat treatment furnace 10, it is possible to reduce the deviation in the position of the first and second openings 61a and 62a, which are the inlets of the exhaust gas flow path, in the furnace chamber 20. In addition, the deviation in the distance from the gas supply ports in the furnace, i.e., the openings 31aa, 31ba, 32aa, 32ba, 33aa, 33ba, to the inlets of the nearest exhaust gas flow path, i.e., the first and second openings 61a and 62a, is small. Further, when observing the furnace chamber 20 from above, the gas supply ports, i.e., the openings 31aa, 31ba, 32aa, 32ba, 33aa, 33ba, are dispersedly arranged along the side wall 17, and the inlets of the exhaust gas flow path, i.e., the first and second openings 61a and 62a, are concentrated in the central portion 21 of the furnace chamber 20, so that a uniform gas flow from the gas supply port to the discharge port can be formed in the entire furnace chamber 20.

[0130] In this way, in the batch-type heat treatment furnace 10, a gas flow with good uniformity can be generated in the furnace chamber 20 from the openings 31aa, 31ba, 32aa, 32ba, 33aa, 33ba of the plurality of gas supply pipes 30 disposed near the side wall 17 toward the first and second openings 61a and 62a, preventing deviation in temperature distribution and deviation in gas composition caused by position.

[0131] In addition, among the plurality of gas supply pipes 30 of the batch-type heat treatment furnace 10, there are at least two gas supply pipes in which the distances from the openings of the respective gas supply pipes to the first opening 61a are equal, such as the first gas supply pipe 31a and the first gas supply pipe 31b, the second gas supply pipe 32a and the second gas supply pipe 32b, and the third gas supply pipe 33a and the third gas supply pipe 33b. The same applies to the second opening 62a. In this way, by dispersedly arranging the openings of the gas supply pipes, the batch-type heat treatment furnace 10 can reduce the deviation in temperature distribution and the deviation in gas composition caused by position in the circumferential direction surrounding the central portion 21 of the furnace chamber 20.

[0132] In addition, the plurality of gas supply pipes 30 of the batch-type heat treatment furnace 10 include the first gas supply pipes 31a and 31b having openings closer to the first opening 61a of the first exhaust gas flow path 61 than the second opening 62a of the second exhaust gas flow path 62, and the third gas supply pipes 33a and 33b having openings closer to the second opening 62a of the second exhaust gas flow path 62 than the first opening 61a of the first exhaust gas flow path 61. In such a batch-type heat treatment furnace 10, by evenly arranging the openings of the first gas supply pipes 31a, 31b and the third gas supply pipes 33a, 33b according to the different heights of the first and second openings 61a and 62a, it is possible to reduce the deviation in the distance of the gas from the supply port to the discharge port, reduce the uneven discharge of the gas, and reduce the deviation in temperature and atmosphere in the furnace chamber 20.

[0133] In addition, in the batch-type heat treatment furnace 10, the position of the lower end 24b of the heater 24 is closer to the first opening 61a of the first exhaust gas flow path 61 than the second opening 62a of the second exhaust gas flow path 62, and the position of the upper end 24a of the heater 24 is closer to the second opening 62a of the second exhaust gas flow path 62 than the second opening 61a of the first exhaust gas flow path 61. Such a heater 24 can extend over a large range in the vertical direction D1 of the furnace chamber 20 and heat the gas flowing in the furnace chamber 20 more uniformly. Therefore, the batch-type heat treatment furnace 10 can effectively reduce the temperature deviation in the furnace chamber 20.

[0134] In addition, as Figure 1 and Figure 2 shown, in the batch-type heat treatment furnace 10, an exhaust gas volume adjustment mechanism 70 having exhaust gas flow rate adjustment blocks 71, 72 is provided at the central opening 61b and the first outer peripheral opening 62b, which are the openings outside the furnace of the first and second exhaust gas flow paths 61, 62.

[0135] As Figure 1 and Figure 2 shown, an exhaust gas chamber 95 is provided above the furnace main body 11 of the batch-type heat treatment furnace 10. The gas discharged from the furnace chamber 20 via the first and second exhaust gas flow paths 61, 62 flows into the exhaust gas chamber 95. The exhaust gas chamber 95 communicates with, for example, a common exhaust gas flow path of the building in which the batch-type heat treatment furnace 10 is provided. In addition, although not shown in Figure 1 and Figure 2 , an exhaust gas duct 96 as shown in Figure 3 may be provided above the first and second exhaust gas flow paths 61, 62 and the exhaust gas volume adjustment mechanism 70, in addition to or instead of the exhaust gas chamber 95.

[0136] Figure 3 is a partial cross-sectional view of the periphery of the exhaust gas flow rate adjustment blocks 71, 72 in the batch-type heat treatment furnace shown in Figure 1 . In Figure 3 , for ease of explanation, the exhaust gas volume adjustment mechanism 70 including the exhaust gas flow rate adjustment blocks 71, 72 is shown in a side view, and the exhaust gas flow paths 61, 62, etc. below the exhaust gas volume adjustment mechanism 70 are shown in a cross-sectional view. In addition, Figure 4 is a schematic view (top view) showing the state of the periphery of the exhaust gas flow rate adjustment blocks 71, 72 as viewed from above in Figures 1 to 3 .

[0137] As Figure 3 and Figure 4As shown, the displacement adjustment mechanism 70 includes a pair of exhaust flow adjustment blocks 71 and 72 that form a variable-width slit 73 therebetween. The exhaust flow adjustment blocks 71 and 72 are each capable of closing at least a part of the central opening 61b of the first exhaust passage 61 and at least a part of the first outer peripheral opening 62b of the second exhaust passage 62.

[0138] As Figure 4 shown, the pair of exhaust flow adjustment blocks 71 and 72 are each arranged to straddle the central opening 61b and the first outer peripheral opening 62b that are concentrically arranged. However, the exhaust flow adjustment blocks 71 and 72 can also be arranged at positions where they do not close a part or all of the central opening 61b and the first outer peripheral opening 62b by widening the width of the slit 73. Further, when viewed from above, one of the pair of exhaust flow adjustment blocks 71 and 72 is arranged on one side of the exhaust pipe central axis C4, and the other is arranged on the other side of the exhaust pipe central axis C4, and they are arranged substantially symmetrically with respect to the exhaust pipe central axis C4 that is also the center of the central opening 61b. Therefore, as Figure 3 shown, the extension line of the exhaust pipe central axis C4 passes through the slit 73.

[0139] As Figure 3 and Figure 4 shown, the displacement adjustment mechanism 70 includes a block holding member 74 that holds the pair of exhaust flow adjustment blocks 71 and 72 so as to be slidable along the relative direction of the pair of exhaust flow adjustment blocks 71 and 72 ( Figure 3 and Figure 4 the left-right direction in). The block holding member 74 is arranged on both sides orthogonal to the relative direction of the pair of exhaust flow adjustment blocks 71 and 72, and includes a pair of guide members 75 extending along the relative direction of the exhaust flow adjustment blocks 71 and 72, and fixing fittings 76 that fix the exhaust flow adjustment blocks 71 and 72 to the guide members 75.

[0140] By sliding the exhaust flow adjustment blocks 71 and 72 along the guide members 75, the width of the slit 73 formed between the exhaust flow adjustment blocks 71 and 72 is changed, and the discharge amount of the gas from the first and second exhaust passages 61 and 62 is adjusted. Figure 5 is a conceptual diagram showing a state in which the width of the slit 73 between the exhaust flow adjustment blocks 71 and 72 shown in Figure 4 has been changed.

[0141] As Figure 4 and Figure 5 shown, a variable-width slit 73 is formed between the opposing surfaces 71a and 72a of the respective exhaust flow adjustment blocks 71 and 72. It is also possible to form irregularities on the opposing surfaces 71a and 72a (see Figure 7)。The exhaust gas flow rate adjustment blocks 71 and 72 can maintain the ratio of the opening areas of the central opening 61b and the first outer peripheral opening 62b within an appropriate range and adjust the discharge amount of the gas.

[0142] In addition, as Figures 3 to 5 shown, the first and second exhaust pipes 51 and 52 are held by the holding rods 55 near the furnace outer side openings, i.e., the central opening 61b and the first outer peripheral opening 62b. The holding rods 55 penetrate the first and second exhaust pipes 51 and 52 in a direction orthogonal to the exhaust pipe central axis C4, and both ends thereof are connected to a holding frame 19 connected to the top wall 18 or the like. The shapes of the opposing surfaces 71a and 72a of the exhaust gas flow rate adjustment blocks 71 and 72 can also be determined in consideration of the partial blockage of the central opening 61b and the first outer peripheral opening 62b by the holding rods 55.

[0143] Figures 1 to 5 The batch-type heat treatment furnace 10 shown can evenly adjust the discharge amounts from the first and second exhaust gas flow paths 61 and 62 with a simple structure, suppress the temperature and atmosphere deviation in the furnace chamber 20, and appropriately perform pressure adjustment of the furnace chamber 20 and the like. In addition, the exhaust gas flow rate adjustment blocks 71 and 72 also exhibit the following effects, that is, by reducing the exhaust gas flow rate, the combustion of coal and the like contained in the gas is promoted, thereby reducing the coal and the like contained in the discharged gas and preventing pollution of the common exhaust gas flow path of the building and the like. In addition, the material of the exhaust gas flow rate adjustment blocks 71 and 72 is not particularly limited, and from the viewpoints of fire resistance and adsorption of coal and the like, it is preferably made of ceramics or the like.

[0144] Second Embodiment

[0145] Figure 6 is a conceptual diagram showing the flow of gas in the batch-type heat treatment furnace 110 of the second embodiment of the present disclosure. Figure 2 The batch-type heat treatment furnace 110 of the embodiment is different from the batch-type heat treatment furnace 10 of the first embodiment in that the exhaust mechanism is a triple-tube structure for the furnace main body 111 and that unevenness 171b and 172b are formed on the opposing surfaces 171a and 172b of the exhaust gas flow rate adjustment blocks 171 and 172 in the exhaust gas amount adjustment mechanism 170. However, the batch-type heat treatment furnace 110 is the same as the Figures 1 to 6 shown batch-type heat treatment furnace 10 except for the differences in the structure of the exhaust pipes and the shapes of the exhaust gas flow rate adjustment blocks 171 and 172. Regarding the description of the batch-type heat treatment furnace 110, the differences from the batch-type heat treatment furnace 10 will be centered on, and the same reference numerals will be given to the common points with the batch-type heat treatment furnace 10, and the description will be omitted.

[0146] As Figure 6As shown, the batch-type heat treatment furnace 110 has a first exhaust pipe 51, a second exhaust pipe 152, and a third exhaust pipe 153 inserted into the furnace chamber 20 from the top wall 18. The first to third exhaust pipes 51, 152, 153 are inserted in the vertical direction D1 so as to pass through the central portion 21 of the furnace chamber 20 when observing the furnace chamber 20 from above. The first to second exhaust pipes 51, 152 are hollow cylindrical shapes, and more specifically, bottomless cylindrical shapes. In addition, in Figure 6 the furnace hearth 12 and the carrier 82 (refer to Figure 1 ) are omitted from illustration.

[0147] The first exhaust pipe 51, the second exhaust pipe 152, and the third exhaust pipe 153 are arranged in a nested manner in the radial direction with their respective central axes aligned. The exhaust flow paths of the batch-type heat treatment furnace 110, namely the first exhaust flow path 61, the second exhaust flow path 162, and the third exhaust flow path 163, are formed by these first to third exhaust pipes 51, 152, 153.

[0148] The diameter of the first exhaust pipe 51 is the smallest among the first to third exhaust pipes 51, 152, 153 and is arranged on the innermost side. The insertion length L1 of the first exhaust pipe 51, similar to the first exhaust pipe 51 shown in Figure 1 and Figure 2 , is longer than the insertion length L2 of the second exhaust pipe 152 into the furnace chamber 20 and the insertion length L3 of the third exhaust pipe 153 into the furnace chamber 20.

[0149] The second exhaust pipe 152 has a larger diameter than the first exhaust pipe 51 and a smaller diameter than the third exhaust pipe 153. The first exhaust pipe 51 is inserted through the inside of the second exhaust pipe 152. The second exhaust pipe 152 has a shorter insertion length into the furnace chamber 20 than the first exhaust pipe 51. As shown in Figure 6 , the insertion length L2 of the second exhaust pipe 152 into the furnace chamber 20 is shorter than the insertion length L1 of the first exhaust pipe 51 into the furnace chamber 20 and longer than the insertion length L3 of the third exhaust pipe 153 into the furnace chamber 20. In addition, the insertion length L2 of the second exhaust pipe 152 into the furnace chamber 20 is longer than the insertion length L2 of the second exhaust pipe 52 shown in Figure 1 and Figure 2 .

[0150] The third exhaust pipe 153 has a larger diameter than the first exhaust pipe 51 and the second exhaust pipe 152. The first exhaust pipe 51 and the second exhaust pipe 152 are inserted through the inside of the third exhaust pipe 153. The third exhaust pipe 153 has a shorter insertion length into the furnace chamber 20 than the second exhaust pipe 152. As shown in Figure 6 , the insertion length L3 of the third exhaust pipe 153 into the furnace chamber 20 is shorter than the insertion length L1 of the first exhaust pipe 51 into the furnace chamber 20 and the insertion length L2 of the second exhaust pipe 152 into the furnace chamber 20.

[0151] As shown Figure 6 in FIG. Figure 6 , an exhaust gas flow path of the batch heat treatment furnace 110 is formed by an exhaust pipe having a three-layer structure composed of first to third exhaust pipes 51, 152, and 153. That is, a first exhaust gas flow path 61 is formed inside the first exhaust pipe 51, and a furnace interior opening of the first exhaust gas flow path 61, i.e., a first opening 61a, is located below a furnace interior opening of a second exhaust gas flow path 162, which is another flow path, i.e., a second opening 162a, and a furnace interior opening of a third exhaust gas flow path 163, i.e., a third opening 163a. The opening shape of the first opening 61a is circular (for example, refer to Figure 7 FIG. Figure 7 ) and is disposed at the center portion 21 of the furnace chamber 20 when viewed from above.

[0152] In addition, as Figure 6 shown in FIG. Figure 6 , a second exhaust gas flow path 162 is formed between the first exhaust pipe 51 and the second exhaust pipe 152. A furnace interior opening of the second exhaust gas flow path 162, i.e., a second opening 162a, is located above the first opening 61a of the first exhaust gas flow path 61 and below the third opening 163a of the third exhaust gas flow path 163. The opening shape of the second opening 162a is a circular ring shape (for example, refer to Figure 7 FIG. Figure 7 ) and is disposed at the center portion 21 of the furnace chamber 20 when viewed from above.

[0153] In addition, as Figure 6 shown in FIG. Figure 6 , a third exhaust gas flow path 163 is formed between the second exhaust pipe 152 and the third exhaust pipe 153. A furnace interior opening of the third exhaust gas flow path 163, i.e., a third opening 163a, is located above the first opening 61a of the first exhaust gas flow path 61 and the second opening 162a of the second exhaust gas flow path 162. The opening shape of the third opening 163a is a circular ring shape (for example, refer to Figure 7 FIG. Figure 7 ) and is disposed at the center portion 21 of the furnace chamber 20 when viewed from above.

[0154] One ends of the first to third exhaust pipes 51, 152, and 153 are located in the furnace chamber 20, but the other ends of the first to third exhaust pipes 51, 152, and 153 are led out of the furnace chamber 20 above the top wall 18. A furnace exterior opening of the first exhaust gas flow path 61, i.e., a central opening 61b, a furnace exterior opening of the second exhaust gas flow path 162, i.e., a first outer peripheral opening 162b, and a furnace exterior opening of the third exhaust gas flow path 163, i.e., a second outer peripheral opening 163b, are aligned in the vertical direction D1 and are arranged in a concentric circle shape.

[0155] Figure 6 The thick arrows shown in FIG. Figure 6 indicate the flow of gas in the furnace chamber 20. As Figure 6 shown in FIG. Figure 6 , in the batch heat treatment furnace 110, gas is discharged from the first opening 61a, the second opening 162a, and the third opening 163a disposed at different heights in the center portion 21 of the furnace chamber 20.

[0156] In this batch-type heat treatment furnace 110, the deviation in the positions of the inlets of the exhaust gas flow paths, i.e., the first to second openings 61a, 162a, 163a, in the furnace chamber 20 is further reduced compared to Figure 2 the batch-type heat treatment furnace 10 shown. As a result, the deviation in the distances from the supply ports of the gas into the furnace, i.e., the openings 31aa, 31ba, 32aa, 32ba, 33aa, 33ba, to the inlets of the nearest exhaust gas flow paths, i.e., the first to third openings 61a, 162a, 163a, is also smaller than that of the batch-type heat treatment furnace 10. Further, when the furnace chamber 20 is viewed from above, by dispersedly arranging the supply ports of the gas, i.e., the openings 31aa, 31ba, 32aa, 32ba, 33aa, 33ba, along the side wall 17 and concentrating the inlets of the exhaust gas flow paths, i.e., the first to third openings 61a, 162a, 163a, at the central portion 21 of the furnace chamber 20, a uniform gas flow from the gas supply port to the discharge port can be formed throughout the furnace chamber 20.

[0157] Thus, in the batch-type heat treatment furnace 110, a gas flow with good uniformity can be generated in the furnace chamber 20 from the openings 31aa, 31ba, 32aa, 32ba, 33aa, 33ba of the plurality of gas supply pipes 30 disposed near the side wall 17 toward the first to third openings 61a, 162a, 163a, preventing deviations in the temperature distribution and deviations in the gas components caused by position.

[0158] Further, the plurality of gas supply pipes 30 of the batch-type heat treatment furnace 110 include: first gas supply pipes 31a, 31b having openings closer to the first opening 61a of the first exhaust gas flow path 61 than the second opening 162a of the second exhaust gas flow path 162, and second gas supply pipes 32a, 32b having openings closer to the second opening 162a of the second exhaust gas flow path 162 than the first opening 61a of the first exhaust gas flow path 61. In this batch-type heat treatment furnace 110, by evenly arranging the openings of the first gas supply pipes 31a, 31b and the second gas supply pipes 32a, 32b according to the differences in the heights of the first and second openings 61a, 162a, the deviation in the distance of the gas from the supply port to the discharge port can be reduced, the uneven discharge of the gas can be reduced, and the deviation in the temperature and atmosphere in the furnace chamber 20 can be reduced.

[0159] As Figure 6 shown, in the batch-type heat treatment furnace 110, similar to Figure 2 the batch-type heat treatment furnace 10 shown, an exhaust gas volume adjustment mechanism 170 having exhaust gas flow rate adjustment blocks 171, 172 is provided at the openings outside the furnace of the first to third exhaust gas flow paths 61, 162, 163, i.e., the central opening 61b, the first outer peripheral opening 162b, and the second outer peripheral opening 163b.

[0160] Figure 7 It means to observe from above Figure 6 Schematic diagram (top view) of the state of the peripheral portion of the exhaust flow adjustment blocks 171 and 172 shown. The exhaust flow adjustment blocks 171 and 172 form a gap 173 of variable width between each other. The exhaust flow adjustment blocks 171 and 172 can both close at least a portion of the central opening 61b of the first exhaust flow path 61, the first peripheral opening 162b of the second exhaust flow path 162, and at least a portion of the second peripheral opening 163b of the third exhaust flow path 63.

[0161] like Figure 6 As shown, a pair of exhaust flow adjustment blocks 171, 172 are respectively arranged to span the central opening 61b, the first peripheral opening 162b and the second peripheral opening 163b arranged in a concentric circle. However, the exhaust flow adjustment blocks 171, 172 can also be arranged at a position that does not block a part or all of the central opening 61b, the first peripheral opening 162b and the second peripheral opening 163b by widening the width of the gap 173. In addition, when viewed from above, one of the pair of exhaust flow adjustment blocks 171, 172 is arranged on one side of the exhaust pipe central axis C4, and the other is arranged on the other side of the exhaust pipe central axis C4, and is arranged roughly symmetrically across the exhaust pipe central axis C4 which is also the center of the central opening 61b.

[0162] Figure 8 It means it has changed Figure 7 1 and 172. The exhaust flow rate adjustment blocks 171 and 172 are arranged along the gap 173. Figure 7 The guide member 75 shown slides to change the width of the gap 173 formed between the exhaust flow rate adjustment blocks 171 and 172 , thereby adjusting the exhaust amount of gas from the first to third exhaust flow paths 61 , 162 , and 163 .

[0163] like Figure 8 and Figure 7 As shown, a gap 173 of variable width is formed between the respective opposing surfaces 171a, 172a of the exhaust flow adjustment blocks 171, 172. Concavities and convexities 171b, 172b are formed on the respective opposing surfaces 171a, 172a across the gap 173, and the exhaust flow adjustment blocks 171, 172 can maintain the ratio of the opening areas of the central opening 61b, the first peripheral opening 162b, and the second peripheral opening 163b within an appropriate range and adjust the exhaust amount of the gas.

[0164] like Figure 8As shown, the unevennesses 171b and 172b formed on the opposing surfaces 171a and 172a are formed such that the first width W1 is narrower than the second width W2. The first width W1 is the width of the gap 173 at a first distance LS1 from the exhaust center axis C4, and the second width W2 is the width of the gap 173 at a second distance LS2 longer than the first distance LS1 from the exhaust center axis C4. In addition, the first distance LS1 and the second distance LS2 are distances in a direction perpendicular to the opposing direction of the exhaust flow adjustment blocks 171 and 172 and the exhaust center axis C4. Further, for example, the first distance LS1 can be set to a distance smaller than the radius of the central opening 61b, and the second distance LS2 can be set to a distance larger than the inner diameter and smaller than the outer diameter of the annular first outer peripheral opening 162b.

[0165] By having such unevennesses 171b and 172b on the opposing surfaces 171a and 172a of the exhaust flow adjustment blocks 171 and 172, even when changing the width of the gap 173, it is possible to keep the ratio of the opening areas of the central opening 61b and the first outer peripheral opening 162b within a highly accurate specified range.

[0166] In addition, the batch-type heat treatment furnace 110 achieves the same effects as the batch-type heat treatment furnace 10 with respect to the common points with the batch-type heat treatment furnace 10.

[0167] Third Embodiment

[0168] Figure 9 is a conceptual diagram showing the gas flow in the batch-type heat treatment furnace 210 of the third embodiment. The batch-type heat treatment furnace 210 is different from the batch-type heat treatment furnace 110 shown, etc., in that the first to third exhaust pipes 251, 252, and 253 are inserted into the furnace chamber 220 from the furnace floor 212, but is the same as the batch-type heat treatment furnace 110 in other points. The description of the batch-type heat treatment furnace 210 focuses on the differences from the batch-type heat treatment furnace 210, and common reference numerals are given to the common points with the batch-type heat treatment furnace 10, and the description is omitted. Figure 6 As shown, etc., the batch-type heat treatment furnace 210 has: a first exhaust pipe 251, a second exhaust pipe 252, and a third exhaust pipe 253 that are inserted into the furnace chamber 220 from the furnace floor 212. The first exhaust pipe 251, the second exhaust pipe 252, and the third exhaust pipe 253 are inserted in the vertical direction D1 so as to pass through the central portion 221 of the furnace chamber 220 when viewed from above the furnace chamber 220. The first exhaust pipe 251, the second exhaust pipe 252, and the third exhaust pipe 253 are arranged in a nested manner in the radial direction with their respective central axes aligned, similarly to the first to third exhaust pipes 51, 152, and 153 shown.

[0169] As Figure 9 shown, etc., the batch-type heat treatment furnace 210 has: a first exhaust pipe 251, a second exhaust pipe 252, and a third exhaust pipe 253 that are inserted into the furnace chamber 220 from the furnace floor 212. The first exhaust pipe 251, the second exhaust pipe 252, and the third exhaust pipe 253 are inserted in the vertical direction D1 so as to pass through the central portion 221 of the furnace chamber 220 when viewed from above the furnace chamber 220. The first exhaust pipe 251, the second exhaust pipe 252, and the third exhaust pipe 253 are arranged in a nested manner in the radial direction with their respective central axes aligned, similarly to the first to third exhaust pipes 51, 152, and 153 shown. Figure 6 shown, etc., the first to third exhaust pipes 51, 152, and 153 are arranged in a nested manner in the radial direction with their respective central axes aligned.

[0170] As Figure 9 shown, the diameter of the first exhaust pipe 251 is the smallest among the first to third exhaust pipes 251 to 253 and is arranged at the innermost side. In addition, for the first exhaust pipe 251, the insertion length L1 of the first exhaust pipe 251 into the furnace chamber 220 is the longest among the first to third exhaust pipes 251 to 253.

[0171] The second exhaust pipe 252 has a larger diameter than the first exhaust pipe 251 and a smaller diameter than the third exhaust pipe 253. The first exhaust pipe 251 passes through the inside of the second exhaust pipe 252. For the second exhaust pipe 252, the insertion length L2 of the second exhaust pipe 252 into the furnace chamber 220 is shorter than the insertion length L1 of the first exhaust pipe 251 into the furnace chamber 220 and longer than the insertion length L3 of the third exhaust pipe 253 into the furnace chamber 220.

[0172] The third exhaust pipe 253 has a larger diameter than the first exhaust pipe 251 and the second exhaust pipe 252. The first exhaust pipe 251 and the second exhaust pipe 252 pass through the inside of the third exhaust pipe 253. The insertion length L3 of the third exhaust pipe 253 into the furnace chamber 220 is the shortest among the first to third exhaust pipes 251 to 253.

[0173] As Figure 9 shown, in the batch-type heat treatment furnace 210, similar to the batch-type heat treatment furnace 110 shown in Figure 6 , an exhaust gas flow path of the batch-type heat treatment furnace 210 is formed by an exhaust pipe having a three-layer structure composed of the first to third exhaust pipes 251 to 253. That is, a first exhaust gas flow path 261 is formed inside the first exhaust pipe 251, and the furnace interior opening of the first exhaust gas flow path 261, i.e., the first opening 261a, is located above the furnace interior opening of the second exhaust gas flow path 262, i.e., the second opening 262a, and the furnace interior opening of the third exhaust gas flow path 263, i.e., the third opening 263a.

[0174] The second exhaust gas flow path 262 is formed between the first exhaust pipe 251 and the second exhaust pipe 252. The furnace interior opening of the second exhaust gas flow path 262, i.e., the second opening 262a, is located below the first opening 261a of the first exhaust gas flow path 261 and above the third opening 263a of the third exhaust gas flow path 263.

[0175] The third exhaust gas flow path 263 is formed between the second exhaust pipe 252 and the third exhaust pipe 253. The furnace interior opening of the third exhaust gas flow path 263, i.e., the third opening 263a, is located below the first opening 261a of the first exhaust gas flow path 261 and the second opening 262a of the second exhaust gas flow path 262.

[0176] One end of each of the first to third exhaust pipes 251 to 253 is located in the furnace chamber 220, but the other ends of the first to third exhaust pipes 251 to 253 are led out of the furnace chamber 220 below the furnace bed 212. The furnace-outside openings of the first exhaust flow path 261, i.e., the central opening 261b, the furnace-outside openings of the second exhaust flow path 262, i.e., the first outer peripheral opening 262b, and the furnace-outside openings of the third exhaust flow path 263, i.e., the second outer peripheral opening 263b, are aligned in the vertical direction D1 and arranged in a concentric circle shape.

[0177] Figure 9 The thick arrows shown indicate the flow of gas in the furnace chamber 220. As Figure 9 shown, in the batch-type heat treatment furnace 210, gas is discharged from the first opening 261a, the second opening 262a, and the third opening 263a arranged at different heights in the central portion 221 of the furnace chamber 220. In such a batch-type heat treatment furnace 210, similar to Figure 6 the batch-type heat treatment furnace 110 shown, it is possible to reduce the deviation in the positions of the inlets of the exhaust flow paths, i.e., the first to third openings 261a, 262a, and 263a, in the furnace chamber 220. In addition, the deviation in the distances from the gas supply ports into the furnace, i.e., the openings 31aa, 31ba, 32aa, 32ba, 33aa, and 33ba, to the inlets of the nearest exhaust flow paths, i.e., the first to third openings 261a, 262a, and 263a, is small. Furthermore, when observing the furnace chamber 220 from above, by dispersedly arranging the gas supply ports, i.e., the openings 31aa, 31ba, 32aa, 32ba, 33aa, and 33ba, along the side wall 17 and concentrating the inlets of the exhaust flow paths, i.e., the first to third openings 261a, 262a, and 263a, at the central portion 21 of the furnace chamber 20, a uniform gas flow from the gas supply port to the discharge port can be formed throughout the furnace chamber 220.

[0178] As Figure 9 shown, in the batch-type heat treatment furnace 210, similar to Figure 6 the batch-type heat treatment furnace 110 shown, an exhaust volume adjustment mechanism 170 having exhaust flow rate adjustment blocks 171 and 172 is provided at the furnace-outside openings of the first to third exhaust flow paths 261, 262, and 263, i.e., the central opening 261b, the first outer peripheral opening 262b, and the second outer peripheral opening 263b.

[0179] Figure 9 The exhaust volume adjustment mechanism 170 shown is arranged in the direction opposite to that of Figure 6 the exhaust volume adjustment mechanism 170 shown, but achieves the same effect as Figure 6 the exhaust volume adjustment mechanism 170 shown. In addition to this, for the common points between the batch-type heat treatment furnace 210 and the batch-type heat treatment furnace 110, the batch-type heat treatment furnace 210 achieves the same effects as the batch-type heat treatment furnace 110.

[0180] As described above, embodiments have been given to explain the batch-type heat treatment furnace of the present disclosure. However, the batch-type heat treatment furnace of the present disclosure is not limited to the above-described embodiments. Needless to say, the batch-type heat treatment furnace of the present disclosure also includes many other embodiments and modification examples. For example, the exhaust pipe of the batch-type heat treatment furnace may be a four-pipe structure or more, and furnace openings with an exhaust flow path having a four-stage structure may be arranged at four or more different heights. In addition, from the viewpoint of forming a uniform air flow, it is more preferable that the number of stages in the height direction of the opening of the exhaust flow path is the same as the number of stages in the height direction of the opening of the supply pipe, or the number of stages in the height direction of the opening of the exhaust flow path is less than the number of stages in the height direction of the opening of the supply pipe.

[0181] In addition, the shapes of the uneven portions 171b and 172b formed on the opposing surfaces 171a and 172a of the exhaust flow rate adjustment blocks 171 and 172 are not limited to Figure 7 and Figure 8 the shapes shown. For example, uneven portions may be formed at positions corresponding to the second outer peripheral opening 163b.

Claims

1. An intermittent heat treatment furnace, comprising: Hearth; a furnace wall having side walls and a top wall arranged to surround the hearth and to form a furnace chamber therein together with the hearth; A heater for heating the furnace chamber; A first hollow cylindrical exhaust pipe, which is inserted into the furnace chamber from the furnace bed or the top wall in the vertical direction; a second exhaust pipe having a larger diameter than the first exhaust pipe, through which the first exhaust pipe is inserted, and a shorter insertion length into the furnace chamber than that of the first exhaust pipe; and A pair of exhaust flow adjustment blocks, which can close at least a portion of the central opening and at least a portion of the first peripheral opening, and form a gap of variable width therebetween across the exhaust pipe center axis which is the center axis of the first exhaust pipe and the second exhaust pipe, the central opening being an opening outside the furnace of the first exhaust flow path formed inside the first exhaust pipe, and the first peripheral opening being an opening outside the furnace of the second exhaust flow path formed between the first exhaust pipe and the second exhaust pipe.

2. The batch heat treatment furnace according to claim 1, wherein: Concavities and convexities are formed on respective opposing surfaces of the pair of exhaust flow rate adjustment blocks across the slit.

3. The batch heat treatment furnace according to claim 2, wherein: The projections and depressions are formed on the opposing surfaces in a manner such that a first width is narrower than a second width, wherein the first width is the width of the gap at a first distance from the center axis of the exhaust pipe, and the second width is the width of the gap at a second distance from the center axis of the exhaust pipe that is longer than the first distance.

4. The batch heat treatment furnace according to claim 1, wherein: The exhaust gas flow rate adjusting block includes a block holding member that holds the pair of exhaust gas flow rate adjusting blocks so as to be slidable along the relative direction of the pair of exhaust gas flow rate adjusting blocks.

5. The batch heat treatment furnace according to claim 1, wherein: The furnace chamber further comprises: a third exhaust pipe having a larger diameter than the second exhaust pipe, the first exhaust pipe and the second exhaust pipe being inserted into the third exhaust pipe, and having a shorter insertion length into the furnace chamber than the second exhaust pipe, The pair of exhaust gas flow rate adjustment blocks can close at least a portion of a second outer peripheral opening that is a furnace outer side opening of a third exhaust gas flow path formed between the second exhaust pipe and the third exhaust pipe.

6. The batch heat treatment furnace according to claim 1, wherein: The furnace chamber has a plurality of gas supply pipes, each of which has an opening in the furnace chamber and supplies gas to the furnace chamber through the side wall. The plurality of gas supply pipes include at least two gas supply pipes having equal distances from openings of the gas supply pipes to a first opening serving as an in-furnace opening of the first exhaust gas flow path, The plurality of gas supply pipes include at least two gas supply pipes having equal distances from openings of the respective gas supply pipes to a second opening serving as an in-furnace opening of the second exhaust gas flow path.

7. The batch heat treatment furnace according to claim 1, wherein: The hearth rotates about a main rotation axis extending in the up-down direction as a rotation axis. The central axis of the exhaust pipe is substantially consistent with an extension line of the main rotation axis.

8. The batch heat treatment furnace according to claim 7, wherein: The hearth includes a sub-hearth that revolves around the main rotation axis as a rotation axis and rotates around a sub-rotation axis that is parallel to the main rotation axis and is a predetermined distance away from the main rotation axis as a rotation axis.

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