Industrial furnace circulation fan

Abstract

To provide an industrial furnace circulation fan which can effectively cool a radial bearing for supporting a rotational axis even if the temperature of a heat treatment space is 1,000°C or more.SOLUTION: An industrial furnace circulation fan 10 comprises: an impeller 14 which rotates at the inside of a heat treatment space Rh at the temperature of 1,000°C or more to form an air flow; a rotational axis 12 of which one end is connected to the impeller 14, and which is rotated around an axis line C1 by a driving part; a first radial bearing 41 which supports the rotational axis 12; a heat insulation layer 17 which separates the first radial bearing 41 from the impeller 14; and a first heat radiation fan 43 which is located between the heat insulation layer 17 and the first radial bearing 41 and rotates together with the rotational axis 12. The first heat radiation fin 43 comprises: plural blades 43b which extend in a radial direction; and a plate body 43a which connects the adjacent blades 43b.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an industrial furnace circulation fan suitable for use in circulating air within a heat treatment space of an industrial furnace. [Background technology]

[0002] 2. Description of the Related Art Industrial furnaces in which various products are subjected to heat treatment in a heat treatment space are provided with industrial furnace circulation fans that form air currents using impellers disposed within the furnace in order to make the temperature within the furnace uniform.

[0003] Industrial furnace circulation fans are equipped with radial bearings that support the rotating shaft that supports the impeller at its tip, and it is important to protect these radial bearings from high heat. In Patent Document 1, an air-cooling system is adopted as a structure for cooling the radial bearings (see Patent Document 1). The air-cooling system is advantageous over the water-cooling system in that it does not require water equipment and is easy to maintain.

[0004] In Patent Document 1, the radial bearing is cooled by generating an airflow using propeller-shaped rotors attached to a rotating shaft. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-229878 A Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, the temperature inside the furnace is set to 900°C to 1000°C, but when the temperature inside the furnace reaches 1000°C or higher, further cooling is required. In Patent Document 1, the radial bearing is cooled by an airflow generated by a propeller fan, but when the temperature inside the furnace reaches 1000°C or higher, there is a limit to the cooling capacity of the airflow generated by the propeller fan alone. In particular, in Patent Document 1, the inner ring of the radial bearing is in contact with the rotating shaft, so high temperature heat is transferred from the impeller via the rotating shaft by thermal conduction, which may damage the radial bearing.

[0007] The present invention has been made in consideration of the above circumstances, and has an object to provide an industrial furnace circulation fan that can effectively cool the radial bearing that supports the rotating shaft even when the heat treatment space is at 1000°C or higher. [Means for solving the problem]

[0008] An industrial furnace circulation fan according to one embodiment of the present invention comprises an impeller that rotates inside a heat treatment space of 1000°C or higher to form an airflow, a rotating shaft connected at one end to the impeller and rotated about its axis by a drive unit, a first radial bearing that supports the rotating shaft, an insulating wall section that separates the first radial bearing and the impeller, and a first heat dissipation fin that is located between the insulating wall section and the first radial bearing and rotates together with the rotating shaft, wherein the first heat dissipation fin comprises a plurality of blades extending radially and a plate body connecting adjacent blades.

[0009] The impeller rotates inside the heat treatment space at 1000°C or higher, forming an air flow in the heat treatment space and making the temperature of the heat treatment space uniform. Since an insulating wall is provided between the impeller and the first radial bearing, it is possible to block the radiant heat in the heat treatment space at 1000°C or higher from being transferred to the first radial bearing side. However, there is a risk that the high temperature heat transferred to the impeller will be transferred to the first radial bearing through the rotating shaft by thermal conduction. Therefore, a first heat dissipation fin is provided between the insulating wall and the first radial bearing, and the heat transferred to the rotating shaft is released through the first heat dissipation fin before being transferred to the first radial bearing. The first heat dissipation fin is composed of blades extending in the radial direction and a plate body connecting adjacent blades. As a result, not only is the heat dissipation performance improved by forming an air flow with the blades, but the heat capacity of the first heat dissipation fin is increased by adding the plate body, and the specific surface area is increased, thereby increasing the amount of heat dissipation. By improving the heat dissipation performance of the first heat dissipation fins in this manner, it is possible to suppress a decrease in the life span of or damage to the first radial bearing.

[0010] In one embodiment of the industrial furnace circulation fan of the present invention, the plate body of the first heat dissipation fin is a circular plate extending in a direction perpendicular to the axis, and the blades of the first heat dissipation fin are arranged to stand upright on one surface of the circular plate.

[0011] Since the first heat dissipation fin is provided with blades that stand on one surface of a disk, a configuration combining a plate body and blades in a simple shape can be realized.

[0012] In one embodiment of the industrial furnace circulation fan of the present invention, a cooling space that houses the first heat dissipation fin and the first radial bearing is formed and separated by the insulating wall portion, and an opening through which outside air can flow is formed in the cooling space and positioned on the opposite side of the insulating wall portion across the first heat dissipation fin, and the first heat dissipation fin is arranged so that the disc is positioned on the insulating wall portion side and the blades are positioned on the opening side.

[0013] A cooling space is formed, separated by a heat insulating wall, and a first heat dissipation fin and a first radial bearing are disposed inside the cooling space. An opening is formed in the cooling space on the opposite side of the heat insulating wall with the first heat dissipation fin in between, and outside air enters and exits through this opening. In other words, outside air for cooling enters the cooling space through the opening, and the outside air after cooling is discharged from the opening. The disk of the first heat dissipation fin is positioned on the insulating wall side, and the blades are positioned on the opening side. As a result, the outside air flowing in from the opening is received by the disk, and then the heat is removed from the disk and the blades, and the blades apply centrifugal force to the outside air, which flows in the radial direction. The cooled outside air that flows in the radial direction is discharged from the outer periphery of the cooling space toward the opening, to the outside of the cooling space. In this way, by positioning the blades erected on the disk on the opening side, the outside air taken in from the opening can be efficiently circulated inside the cooling space, improving the cooling efficiency.

[0014] In the industrial furnace circulation fan according to one aspect of the present invention, the cooling space has a cylindrical shape with an outer periphery being a cylindrical surface centered on the axis.

[0015] By making the cooling space cylindrical, we were able to create as large a space as possible, which allows the outside air that flows into the cooling space to circulate widely, improving the cooling efficiency.

[0016] In an industrial furnace circulation fan according to one embodiment of the present invention, between the first radial bearing and the drive unit, there are provided, in order from the first radial bearing side, a second heat dissipation fin that rotates together with the rotating shaft, and a second radial bearing that supports the rotating shaft.

[0017] By providing the second heat dissipation fins on the first radial bearing side, the airflow created by the second heat dissipation fins can be directed toward the first radial bearing side to promote cooling. In addition, the second heat dissipation fins can dissipate heat from the rotating shaft, further suppressing heat input to the second radial bearing.

[0018] In the industrial furnace circulation fan according to one aspect of the present invention, the first heat dissipation fin has an outer diameter larger than that of the second heat dissipation fin.

[0019] By making the outer diameter of the first heat dissipation fin larger than that of the second heat dissipation fin, the amount of heat dissipation from the first heat dissipation fin, which is in a thermally severe environment, is increased, thereby enabling the first radial bearing to be cooled more effectively.

[0020] In the industrial furnace circulation fan according to one aspect of the present invention, the first heat dissipation fin is configured from a plurality of divided bodies that can be assembled by accessing from the outer circumferential side of the rotating shaft.

[0021] The first heat dissipation fin is composed of multiple segments and can be accessed and assembled from the outer periphery of the rotating shaft, which not only simplifies maintenance but also makes it easy to replace the first heat dissipation fin with a different outer diameter depending on the required cooling capacity. Effect of the Invention

[0022] Even if the heat treatment space is at 1000°C or higher, the radial bearing that supports the rotating shaft can be effectively cooled. [Brief description of the drawings]

[0023] [Figure 1] 1 is an overall view showing an industrial furnace equipped with an industrial furnace circulation fan according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view showing the industrial furnace circulation fan of FIG. 1. [Diagram 3] FIG. 3 is a plan view showing the industrial furnace circulation fan of FIG. 2. [Figure 4] FIG. 3 is a vertical cross-sectional view showing the industrial furnace circulation fan of FIG. 2. [Diagram 5] FIG. 4 is a plan view showing a first heat dissipation fin. [Figure 6] 6 is a vertical cross-sectional view of the first heat dissipation fin of FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an industrial furnace circulation fan according to the present invention will be described below with reference to the drawings. As shown in Fig. 1, the industrial furnace 1 includes a main body 3 in which a heat treatment space Rh is formed, and legs 5 that support the main body from below on an installation surface B. The main body 3 is provided with a burner 7. The burner 7 uses, for example, hydrogen as fuel, and heats the heat treatment space to 1000°C or higher and 1300°C or lower, for example, to about 1200°C, using the resulting combustion gas. Note that instead of a combustion furnace using the burner 7, an electric furnace that uses heating wires or the like for heating may be used.

[0025] An industrial furnace circulation fan 10 is attached to an opening formed in the upper part of the main body 3 of the industrial furnace 1. The industrial furnace circulation fan 10 includes a rotating shaft 12 that rotates around an axis C1, and an impeller 14. The rotating shaft 12 is made of stainless steel such as SUS316. The impeller 14 is located inside the heat treatment space Rh. In this embodiment, the axis C1 about which the rotating shaft 12 rotates is oriented in the vertical direction, but the present invention is not limited to this, and may be inclined with respect to the vertical direction or oriented in the horizontal direction.

[0026] As shown in FIG. 2, the industrial furnace circulation fan 10 has a rectangular outer plate 15 fixed to the main body 3 of the industrial furnace 1 by bolts or the like through a plurality of mounting holes 16.

[0027] A plurality of heat insulating layers (heat insulating wall portions) 17 are laminated so as to be in contact with the lower surface of the outer plate 15. The heat insulating layers 17 are located above the impeller .

[0028] A first cylindrical portion 18 and a second cylindrical portion 19 are attached in this order toward the top at the center of the outer plate 15. A plurality of openings 18a are formed in the cylindrical surface of the first cylindrical portion 18. A plurality of openings 19a are also formed in the cylindrical surface of the second cylindrical portion 19. A punching metal 21 having a large number of holes formed therein is attached to each of the openings 18a, 19a.

[0029] Four ribs 22 are fixed between the first cylindrical portion 18 and the outer plate 15. Each rib 22 has a substantially right-angled triangular shape when viewed from the front, and is provided on the outer plate 15 at equal angular intervals (90°). This allows the first cylindrical portion 18 to be firmly fixed to the outer plate.

[0030] An electric motor 20 is attached above the second cylindrical portion 19. The operation of the electric motor 20 is controlled by commands from a control unit (not shown). The electric motor 20 rotates the rotating shaft 12 (see FIG. 1) at 800 rpm or more, preferably at 1000 rpm.

[0031] The outer plate 15 has sector-shaped openings 24 formed at predetermined intervals around the first cylindrical portion 18. A metal grating 25 is attached to the openings 24. As shown in Fig. 3, four openings 24 are provided at equal angular intervals. Outside air (air) flows between the openings 24 and a cooling space Rc (see Fig. 4) formed below the outer plate 15.

[0032] 4 shows a vertical cross section of the above-mentioned industrial furnace circulation fan 10. As shown in the figure, an electric motor 20, a rotating shaft 12, and an impeller 14 are provided from top to bottom in this order, with a common axis C1 extending vertically. The first cylindrical portion 18 and the second cylindrical portion 19 also share the central axis C1.

[0033] The main shaft of the electric motor 20 and the upper end of the rotating shaft 12 are connected by a flange-type coupling 29. The lower end of the rotating shaft 12 and the shaft portion 14a of the impeller 14 are fixed at a fixing portion 31. At the fixing portion 31, the rotating shaft 12 and the shaft portion 14a are connected by an embedded bolt or the like so that they form cylindrical surfaces of the same outer diameter. Note that the rotating shaft in the present invention includes not only the rotating shaft 12 but also the shaft portion 14a.

[0034] The impeller 14 has a plurality of blades 14b extending in the radial direction, and is, for example, an axial flow fan. The impeller 14 rotates about an axis C1 to generate an airflow in the heat treatment space Rh, which stirs the air. The impeller 14 is integrally formed by casting. The material of the impeller 14 is a heat-resistant alloy that can withstand high temperatures of 1000°C or higher, unlike the rotating shaft 12, which is made of austenitic stainless steel such as SUS304, SUS316, or SUS310S.

[0035] A cooling space Rc is formed above the multiple insulating layers 17. The cooling space Rc is surrounded between the upper outer plate 15 and the lower bottom plate 33. The side of the cooling space Rc is surrounded by the upper insulating layer 17 and is formed into a cylindrical surface. As a result, the outer shape of the cooling space Rc is a cylindrical shape with the axis C1 as the central axis and the same diameter from the lower bottom plate 33 to the upper outer plate 15. This cylindrical shape is, for example, a flat shape with the outer diameter larger than the dimension in the axis C1 direction. The multiple insulating layers 17 are fixed to the outer plate 15 by a hanging bolt 35 whose upper end is fixed to the outer plate 15.

[0036] A gland packing 37 is provided in the center of the bottom plate 33 as a shaft seal. The gland packing 37 is located at the height of the lower part of the rotating shaft 12, and is made of inorganic fiber having heat resistance of, for example, about 180°C. Two oil seals 39 made of fluororubber are provided above and below the gland packing 37. The gland packing 37 and the two oil seals 39 seal the high-temperature gas that flows from the heat treatment space Rh along the shaft part 14a of the impeller 14 and the outer circumferential surface of the rotating shaft 12 into the cooling space Rc.

[0037] A first radial bearing 41 that rotatably supports the rotating shaft 12 is provided in the center of the outer plate 15. The first radial bearing 41 is a ball bearing, and an inner ring is fixed to the rotating shaft 12. Oil can be supplied to the first radial bearing 41 through an oil supply pipe 41a.

[0038] A first heat dissipating fin 43 is provided between the first radial bearing 41 and the upper oil seal 39. The first heat dissipating fin 43 is disposed in the cooling space Rc. That is, the first heat dissipating fin 43 is disposed between the impeller 14 and the first radial bearing 41. The first heat dissipating fin 43 is fixed to the rotating shaft 12 and thereby rotates together with the rotating shaft 12. The first heat dissipating fin 43 is made of a material having a higher thermal conductivity than cast iron, for example, an aluminum alloy.

[0039] As shown in Figs. 5 and 6, the first heat dissipation fin 43 includes a plurality of vanes 43b extending in the radial direction and a plate body 43a supporting each vane 43b from below. The plate body 43a is a disk and connects adjacent vanes 43b. Each vane 43b is provided so as to extend in the radial direction from a boss portion 43c and is provided so as to stand upward from the upper surface of the plate body 43a. The number of vanes 43b is six in Fig. 5, but may be seven or more or five or less. The number is preferably four to six, but is determined appropriately depending on the cost and the casting precision.

[0040] As can be seen from Fig. 5, the first heat dissipating fin 43 has a split structure that can be split into two pieces. In Fig. 5, the split surface of the first heat dissipating fin 43 is provided in the vertical direction. The two split pieces can be integrated into an integral structure by inserting bolts through holes 43b1 formed in the blades 43b and fixing them with nuts.

[0041] The first heat dissipating fin 43 can have an extension portion 43B located on the outer periphery of the central portion 43A in addition to the central portion 43A located in the center when viewed from above (as shown in FIG. 5). The central portion 43A and the extension portion 43B are connected by bolts and nuts 43e (see FIG. 6) using a plurality of extension holes 43d formed in the circumferential direction. By using the extension portion 43B, the blades 43b of the first heat dissipating fin 43 can be lengthened in the radial direction, and the diameter of the plate body 43a can be enlarged. Note that the first heat dissipating fin 43 shown in FIG. 4 is the first heat dissipating fin 43 with only the central portion 43A without the extension portion 43B attached.

[0042] As shown in FIG. 4, the first heat dissipation fin 43 is attached so that the plate body 43a faces downward and the blades 43b faces upward.

[0043] A second heat dissipating fin 45 is provided above the first radial bearing 41. The second heat dissipating fin 45 is made of the same material and has the same shape as the first heat dissipating fin 43, and is fixed to the rotating shaft 12 to rotate together with the rotating shaft 12. The second heat dissipating fin 45 is located inside the first cylindrical portion 18.

[0044] The second heat dissipating fin 45 is attached such that the plate body 45a faces upward and the blades 45b faces downward. That is, the blades 45b of the second heat dissipating fin 45 and the blades 43b of the first heat dissipating fin 43 face each other.

[0045] The second heat dissipation fins 45 rotate to generate an airflow, causing air to flow in and out via openings 18a (see FIG. 2) provided in the side wall of the first cylindrical portion 18. Furthermore, the outer plate 15 has a plurality of openings 15a formed in an area located inside the first cylindrical portion 18. These openings 15a connect the inside of the first cylindrical portion 18 to the cooling space Rc. Due to the action of the second heat dissipation fins 45, air flows in and out between the inside of the first cylindrical portion 18 and the cooling space Rc via the openings 15a.

[0046] A second radial bearing 47 is provided above the second heat dissipation fin 45. The second radial bearing 47 is a ball bearing, and an inner ring is fixed to the rotating shaft 12. The second radial bearing 47 is located inside the second cylindrical portion 19, and can be oiled via an oil supply pipe 47a. The upper end of the rotating shaft 12 is rotatably supported by the second radial bearing 47.

[0047] Next, the operation of the industrial furnace circulation fan 10 having the above configuration will be described. The inside of the heat treatment space Rh of the industrial furnace 1 is heated to a high temperature of 1000°C or more, for example, about 1200°C, by the burner 7. At this time, the electric motor 20 is driven by a command from a control unit (not shown), and the rotary shaft 12 is rotated to rotate the impeller 14. The rotation of the impeller 14 generates an airflow inside the heat treatment space Rh of the industrial furnace 1, which stirs the air. This makes the temperature inside the heat treatment space Rh uniform, and the material to be treated is heat-treated.

[0048] The impeller 14 is exposed to a high temperature of about 1200°C, and this high temperature heat is transferred by thermal conduction to the rotating shaft 12 via the shaft portion 14a of the impeller 14. The heat transferred to the rotating shaft 12 is dissipated by the first heat dissipation fins 43 rotating in the cooling space Rc. The first heat dissipation fins 43 are made of an aluminum alloy with a relatively high thermal conductivity, and therefore can dissipate heat effectively.

[0049] The rotation of the first heat dissipation fins 43 agitates the air in the cooling space Rc, generating an airflow. Since the blades 43b of the first heat dissipation fins 43 face upward, i.e., toward the outer plate 15, the air in the cooling space Rc and the outside air flow in and out through the openings 24 provided in the outer plate 15, as shown by the arrow A1. In this way, the heat transferred to the rotating shaft 12 is released by convection heat transfer caused by the airflow generated by the first heat dissipation fins 43.

[0050] The first heat dissipating fin 43 has an increased heat capacity by including not only the blades 43b but also the plate body 43a, and can therefore receive a large amount of heat transferred from the rotating shaft 12. Furthermore, the first heat dissipating fin 43 has an increased specific surface area by including the plate body 43a, and thus more heat is released to the cooling space Rc by convection heat transfer.

[0051] By making the cooling space Rc cylindrical, the volume of the cooling space Rc is made as large as possible, which allows a large circulating flow to be formed within the cooling space Rc, thereby promoting heat dissipation.

[0052] In this way, the first heat dissipation fins 43 dissipate the heat of the rotating shaft 12 to the outside through the cooling space Rc, so that the high heat transmitted to the rotating shaft 12 can be prevented from being transmitted to the first radial bearing 41.

[0053] The second heat dissipation fins 45 provided on the first cylindrical portion 18 rotate together with the rotating shaft 12. This generates an airflow inside the first cylindrical portion 18, and air flows in and out through the openings 18a of the first cylindrical portion 18. At the same time, the blades 45b of the second heat dissipation fins 45 attached facing downward cause air to flow from the first cylindrical portion 18 into the cooling space Rc through the openings 15a formed in the outer plate 15, as shown by the arrow A2. This further promotes the release of heat transferred to the rotating shaft 12.

[0054] As described above, the industrial furnace circulation fan 10 according to this embodiment provides the following advantages.

[0055] The impeller 14 rotates in the heat treatment space Rh at 1000°C or higher, forming an air flow in the heat treatment space Rh and making the temperature of the heat treatment space Rh uniform. Since a plurality of heat insulating layers 17 are provided between the impeller 14 and the first radial bearing 41, it is possible to block the radiant heat of the heat treatment space Rh at 1000°C or higher from being transferred to the first radial bearing 41 side. However, there is a risk that the high-temperature heat transferred to the impeller 14 will be transferred to the first radial bearing 41 through the rotating shaft 12 by thermal conduction. Therefore, a first heat dissipation fin 43 is provided between the heat insulating layer 17 and the first radial bearing 41, and the heat transferred to the rotating shaft 12 is released through the first heat dissipation fin 43 before being transferred to the first radial bearing 41. The first heat dissipation fin 43 is composed of blades 43b extending in the radial direction and a plate body 43a connecting adjacent blades 43b. As a result, not only does the blades 43b form an airflow to improve heat dissipation, but the addition of the plate 43a increases the thermal capacity of the first heat dissipation fins and increases the specific surface area, thereby increasing the amount of heat dissipation. By improving the heat dissipation by the first heat dissipation fins 43 in this way, it is possible to suppress a decrease in the life span or damage to the first radial bearing 41.

[0056] The blades 43b are provided so as to stand on one surface of the circular plate body 43a of the first heat dissipating fin 43. This makes it possible to realize the first heat dissipating fin 43 which combines the plate body 43a and the blades 43b in a simple shape.

[0057] A cooling space Rc is formed, partitioned by the insulating layer 17, and a first heat dissipation fin 43 and a first radial bearing 41 are disposed inside this cooling space Rc. An opening 15a is formed in the cooling space Rc on the opposite side of the insulating layer 17 with the first heat dissipation fin 43 in between, and outside air enters and exits through this opening 15a. That is, outside air for cooling enters the cooling space Rc through the opening 15a, and the outside air after cooling is discharged from the opening 15a.

[0058] The plate body 43a of the first heat dissipation fin 43 is positioned on the insulating layer 17 side, and the blades 43b are positioned on the opening 15a side. As a result, the outside air flowing in from the opening 15a is received by the plate body 43a, and then the heat is removed from the plate body 43a and the blades 43b, and the blades 43b are applied with centrifugal force to flow in the radial direction. The cooled outside air that flows in the radial direction is discharged from the outer periphery of the cooling space Rc toward the opening 15a to the outside of the cooling space Rc. In this way, by positioning the blades 43b erected on the plate body 43a on the opening 15a side, the outside air taken in from the opening 15a is efficiently circulated inside the cooling space Rc, thereby improving the cooling efficiency.

[0059] By making the cooling space Rc cylindrical, we were able to create as large a space as possible, which allows the outside air that flows into the cooling space Rc to circulate widely, improving the cooling efficiency.

[0060] By providing the second heat dissipation fins 45 on the first radial bearing 41 side, the airflow formed by the second heat dissipation fins 45 can be directed toward the first radial bearing 41 side to promote cooling. In addition, since the second heat dissipation fins 45 can dissipate heat from the rotating shaft 12, the heat input to the second radial bearing 47 can be further suppressed.

[0061] 5 and 6, by attaching the extension 43B, the outer diameter of the first heat dissipation fin 43 can be made larger than that of the second heat dissipation fin 45. This increases the amount of heat dissipation of the first heat dissipation fin 43, which is in a thermally severe environment. This makes it possible to more effectively cool the first radial bearing 41.

[0062] The first heat dissipation fin 43 is composed of multiple divided bodies and can be assembled by accessing it from the outer periphery side of the rotating shaft 12. This makes maintenance easy and allows the first heat dissipation fin 43 to be easily replaced with one having a different outer diameter depending on the required cooling capacity. [Explanation of symbols]

[0063] 1. Industrial furnace 3. Main unit 5 Legs 7. Burner 10. Industrial furnace circulation fan 12 Rotation axis 14 Impeller 14a Shaft 14b Feather 15 Outer plate 15a opening 16 Mounting holes 17 Insulation layer (insulation wall) 18 First cylindrical section 18a opening 19 Second cylindrical section 19a aperture 20 Electric motor 21 Punching metal 22 Ribs 24 Opening 25 Grating 29 Flange type coupling 31 Fixed part 33 Bottom plate 35 Hanging bolt 37 Gland packing 39 Oil seal 41 No. 1 radial bearing 41a Fuel pipe 43 First heat dissipation fin 43a plate 43b Feather 43b1 Hole 43c Boss part 43d Extension hole 43e Bolts and nuts 43A Central part 43B Extension 45 Second heat dissipation fin 45a plate 45b Feather 47 Second radial bearing 47a Fuel Pipe B Installation surface C1 axis rc cooling space Rh heat treatment space

Claims

1. an impeller that rotates inside a heat treatment space at 1000° C. or higher to form an air flow; A rotating shaft having one end connected to the impeller and rotated about an axis by a driving unit; A first radial bearing that supports the rotating shaft; a heat insulating wall portion that separates the first radial bearing and the impeller; a first heat dissipation fin located between the heat insulating wall portion and the first radial bearing and rotating together with the rotating shaft; Equipped with The first heat dissipation fin of the industrial furnace circulation fan has a plurality of blades extending in a radial direction and a plate body connecting adjacent blades.

2. The plate body of the first heat dissipation fin is a circular plate extending in a direction perpendicular to the axis, 2. The industrial furnace circulation fan according to claim 1, wherein the blades of the first heat dissipation fin are provided so as to stand on one surface of the disk.

3. a cooling space that houses the first heat dissipation fin and the first radial bearing is formed in a state that the cooling space is partitioned by the heat insulating wall portion, an opening through which outside air can flow is formed in the cooling space, the opening being located on the opposite side of the insulating wall portion across the first heat dissipation fin; 3. The industrial furnace circulation fan according to claim 2, wherein the first heat dissipation fin is provided so that the disk is located on the insulating wall side and the blade is located on the opening side.

4. 4. The industrial furnace circulation fan according to claim 3, wherein the cooling space has a cylindrical shape with an outer periphery thereof being a cylindrical surface centered on the axis.

5. 2. The industrial furnace circulation fan according to claim 1, wherein a second heat dissipation fin that rotates together with the rotating shaft and a second radial bearing that supports the rotating shaft are provided between the first radial bearing and the drive unit, in that order from the first radial bearing side.

6. 6. The industrial furnace circulation fan according to claim 5, wherein the first heat dissipation fin has an outer diameter larger than that of the second heat dissipation fin.

7. 2. The industrial furnace circulation fan according to claim 1, wherein the first heat dissipation fin is constituted by a plurality of divided bodies that can be assembled by accessing from the outer periphery side of the rotating shaft.

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