Heat-resistant circulating fan for cooling

Abstract

This utility model relates to a heat-resistant circulating fan for cooling. The output shaft of a variable frequency motor is connected to the upper end of a central shaft via a coupling. The upper part of the central shaft is housed in a bearing housing, and the lower middle part of the central shaft passes through a heat insulation box. A double-suction impeller is fitted onto the lower end of the central shaft. The bottom of the heat insulation box is connected to the first air inlet at the top of the double-suction impeller. Multiple air inlets are evenly distributed around the top circumference of the heat insulation box. A second air inlet is located at the bottom of the double-suction impeller. When the double-suction impeller rotates with the central shaft, it draws external airflow above the top of the heat insulation box through the first air inlet along the radial direction of the double-suction impeller, while simultaneously drawing hot air below the heat insulation box through the second air inlet along the radial direction of the double-suction impeller. This allows the cold air entering the furnace to mix rapidly with the hot air inside, lowering the furnace temperature. The continuous circulation and stirring by the double-suction impeller achieves uniform furnace temperature. A single fan can simultaneously achieve both temperature reduction and temperature uniformity.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal fan technology, specifically to a heat-resistant circulating fan for cooling. Background Technology

[0002] In the heat treatment process of metal products, to ensure the performance of the metal products, the products must be slowly cooled after heating. The temperature is gradually reduced from the high-temperature zone to the holding zone and then the slow-cooling zone according to the temperature process curve. It is crucial to ensure uniform temperature within each zone of the heat treatment furnace to provide a consistent temperature environment for each metal product and guarantee a high product qualification rate. Since the heat treatment temperature requirements differ for each zone, the high-temperature zone needs to be cooled within a furnace reaching up to 1000℃. To ensure uniform temperature within the furnace, high-temperature resistant hot air circulation fans are required. To further reduce the furnace temperature, ambient air needs to be introduced, and additional fans are needed to introduce external airflow. This results in a relatively large number of fans required for the heat treatment furnace, necessitating a reasonable arrangement to achieve effective cooling and temperature uniformity, making the overall structure quite complex. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a heat-resistant circulating fan for cooling, which solves the problem that the temperature inside the heat treatment furnace needs to drop uniformly and the fan needs to meet the high temperature resistance requirements.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0005] A heat-resistant circulating fan for cooling includes a variable frequency motor. The output shaft of the variable frequency motor is connected to the upper end of a central shaft via a coupling. The upper part of the central shaft is mounted in a bearing housing via two separate bearings. The lower middle part of the central shaft passes through a heat insulation box. A double-suction impeller is fitted on the lower end of the central shaft. The bottom of the heat insulation box is connected to the first air inlet at the top of the double-suction impeller. A second air inlet is provided at the bottom of the double-suction impeller. When the double-suction impeller rotates with the central shaft, it can draw the external airflow above the top of the heat insulation box from the first air inlet along the radial direction of the double-suction impeller, and at the same time draw the hot air below the heat insulation box from the second air inlet along the radial direction of the double-suction impeller.

[0006] As a preferred embodiment, the top of the bearing housing is fixed to the bottom of the variable frequency motor, the bottom of the bearing housing is fixed to the top of the heat insulation box, and a cooling wheel is fitted on the central shaft near the lower end of the bearing housing. The cooling wheel is located between the lowest bearing and the heat insulation box, and ventilation holes are provided on the bearing housing around the cooling wheel.

[0007] In a preferred embodiment, the top of the heat insulation box is a fixed plate, and four air inlets are evenly distributed around the fixed plate. An adjustment plate is provided on the top of the fixed plate, and the central through hole of the adjustment plate is fitted onto a bearing seat. Four adjustment holes are evenly distributed around the annular circumference of the adjustment plate, and an adjustment handle is provided on the top of the adjustment plate. When the adjustment plate is rotated by the adjustment handle, the overlapping position of the four adjustment holes on the adjustment plate and the air inlets on the fixed plate can be changed, thereby adjusting the airflow.

[0008] As a preferred embodiment, the side wall of the heat insulation box is provided with heat insulation fiber cotton, and a horizontal perforated partition is provided in the middle of the inner cavity of the heat insulation box.

[0009] As a preferred embodiment, the dual-suction impeller includes two annular and opposite first and second front discs. A flat rear disc is arranged parallel to the opposite side of the first and second front discs. The rear disc is close to the side of the first front disc. Multiple blades distributed radially circumferentially are connected to the opposite end faces of the first and second front discs. The middle part of the blades passes vertically through the rear disc. The two sides of the blades are respectively vertically arranged on the opposite side end faces of the first and second front discs. The center of the rear disc is a bushing. The central through hole on one side of the first front disc is the first air inlet, and the central through hole on one side of the second front disc is the second air inlet.

[0010] In a preferred embodiment, the blades are distributed in 12 circumferentially.

[0011] As a preferred embodiment, a cooling cavity is arranged around the lowest bearing on the bearing housing, and water inlets and outlets are provided on opposite sides of the cooling cavity.

[0012] In a preferred embodiment, the ratio of the distance from the rear disc to the first front disc to the distance from the rear disc to the second front disc is 1:2.

[0013] The beneficial effects of this utility model are as follows: The blower is installed on the top of the heat treatment furnace. The part of the blower below the fixed plate on the top of the heat insulation box extends into the furnace. A double-suction impeller is fitted at the lower end of the central shaft. An air inlet is opened on the top of the heat insulation box of the blower. The first air inlet at the top of the double-suction impeller draws in cold air from the outside, and the second air inlet at the bottom of the double-suction impeller draws in hot air from inside the heat treatment furnace. This allows the cold air entering the furnace to mix rapidly with the hot air inside the furnace, causing the temperature inside the furnace to drop. Through continuous circulation and stirring by the double-suction impeller, the furnace temperature becomes uniform. One blower can simultaneously achieve the two functions of temperature reduction and temperature uniformity. The central shaft is outside the heat treatment furnace. The lowest bearing in the section is cooled by both air and water to ensure the stability of bearing operation and improve the heat resistance of the fan. The top of the central shaft is connected to the variable frequency motor through a flexible coupling to increase the service life of the central shaft. Insulating fiber cotton is installed on the side walls of the heat insulation box as an insulation layer to reduce the axial leakage of hot air in the furnace, which may damage the bearing and extend the life of the fan. The fan is suitable for the requirement of regular cooling in the high temperature zone, heat preservation zone and slow cooling zone during the heat treatment of metal products to ensure uniform temperature change in the furnace. It is suitable for installation on other heat treatment furnaces with uniform hot air, including tempering furnaces, aging furnaces, drying furnaces, glass annealing furnaces, and decorating furnaces. Attached Figure Description

[0014] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, wherein:

[0015] Figure 1 This is a cross-sectional view of the present invention;

[0016] Figure 2 This is a top view of the present invention;

[0017] Figure 3 This is a cross-sectional view of the double-suction impeller of this utility model;

[0018] Figure 4 for Figure 3 The right-side view;

[0019] Figures 1-4 Explanation of reference numerals in the attached diagram: 1. Variable frequency motor; 2. Coupling; 3. Bearing housing; 4. Air-cooled impeller; 5. Insulating fiber cotton; 6. Perforated partition; 7. Double suction impeller; 8. Fixed plate; 9. Adjusting plate; 10. Cooling chamber; 11. Water inlet; 12. Water outlet; 13. Adjusting handle; 14. Air inlet hole; 15. Adjusting hole; 16. Heat insulation box; 17. Central shaft; 71. First air inlet; 72. Second air inlet; 73. Rear plate; 74. First front plate; 75. Second front plate; 76. Blade. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] This utility model describes a heat-resistant circulating fan for cooling; see also... Figures 1-4 As shown, the system includes a variable frequency motor 1. The output shaft of the variable frequency motor 1 is connected to the upper end of a central shaft 17 via a coupling 2. The upper part of the central shaft 17 is mounted in a bearing housing 3 via two separate bearings. The lower middle part of the central shaft 17 passes through a heat insulation box 16. A double suction impeller 7 is fitted onto the lower end of the central shaft 17. The bottom of the heat insulation box 16 is aligned with the first air inlet 71 at the top of the double suction impeller 7. The bottom of the heat insulation box 16 extends downwards to the top opening of the first air inlet 71. The top of the heat insulation box 16... The fan has multiple air inlets 14 evenly distributed around its circumference, and a second air inlet 72 is provided at the bottom of the double-suction impeller 7. When the circulating fan is installed on the heat treatment furnace, the part of the fan below the fixed plate 8 of the heat insulation box 16 is located inside the furnace. During operation, when the double-suction impeller 7 rotates with the central shaft 17, it can draw the external airflow above the top of the heat insulation box 16 from the first air inlet 71 along the radial direction of the double-suction impeller 7, and at the same time draw the hot air below the heat insulation box 16 from the second air inlet 72 along the radial direction of the double-suction impeller 7.

[0022] Specifically, the blower is installed on top of the heat treatment furnace. The part of the blower below the fixed plate 8 of the heat insulation box 16 extends into the heat treatment furnace. When the double suction impeller 7, made of high-temperature resistant alloy material 800H, rotates, the air outside the heat treatment furnace enters through the air inlet 14 at the top of the heat insulation box 16, enters through the first air inlet 71 facing upwards at the top of the double suction impeller 7, and is radially output from the upper circumferential side of the double suction impeller 7. At the same time, the second air inlet 72 facing downwards at the bottom of the double suction impeller 7 draws in the hot air inside the furnace and outputs it radially from the lower circumferential side of the double suction impeller 7. In this way, the cold air entering from the outside and the hot air inside the furnace flow and mix together at the same time, so as to achieve a uniform cooling process.

[0023] In this embodiment, the top of the bearing housing 3 is fixed to the bottom of the variable frequency motor 1, and the bottom of the bearing housing 3 is fixed to the top of the heat insulation box 16. A cooling wheel 4 is fitted on the central shaft 17 near the lower end of the bearing housing 3. The cooling wheel 4 is located between the lowest bearing and the heat insulation box 16, and ventilation holes are provided on the bearing housing 3 around the cooling wheel 4. The cooling wheel 4 is outside the heat insulation box 16, providing heat dissipation to the central shaft 17 and the lowest bearing, ensuring stable operation of the bearing. The bearing housing 3 adopts integral casting technology, realizing the support of two separate bearings on the central shaft 17. This not only ensures the installation accuracy of the two bearings and facilitates lubrication, but also improves the installation accuracy of the central shaft 17 and enhances the strength and rigidity of the central shaft 17.

[0024] In this embodiment, the top of the heat insulation box 16 is set as a fixed plate 8, and four air inlets 14 are evenly distributed around the fixed plate 8. An adjusting plate 9 is set on the top of the fixed plate 8. The central through hole of the adjusting plate 9 is fitted onto the bearing seat 3. Four adjusting holes 15 are evenly distributed around the annular circumference of the adjusting plate 9. An adjusting handle 13 is set on the top of the adjusting plate 9. When the adjusting plate 9 is rotated by the adjusting handle 13, the overlapping position of the four adjusting holes 15 on the adjusting plate 9 and the air inlets 14 on the fixed plate 8 can be changed, thereby adjusting the airflow. The cold airflow entering the heat treatment furnace can be adjusted to ensure that the amount of cold air entering the furnace is in accordance with the process requirements, thus ensuring the required quality of different products in the furnace.

[0025] In this embodiment, heat-insulating fiber cotton 5 is provided on the side wall of the heat insulation box 16, and a horizontal perforated baffle 6 is provided in the middle of the inner cavity of the heat insulation box 16. The perforated baffle 6 prevents external objects from falling into the heat treatment furnace with the airflow, and can also effectively block the backflow of airflow when air is introduced.

[0026] In this embodiment, the double-suction impeller 7 includes two annular and opposite first front discs 74 and second front discs 75. A flat rear disc 73 is arranged parallel to the opposite side of the first front discs 74 and second front discs 75. The rear disc 73 is close to the side of the first front disc 74. Multiple blades 76 distributed radially circumferentially are connected to the opposite end faces of the first front discs 74 and second front discs 75. The middle part of the blades 76 passes vertically through the rear disc 73. The two sides of the blades 76 are respectively vertically arranged on the opposite side end faces of the first front discs 74 and second front discs 75. The center of the rear disc 73 is a bushing 77. The central through hole on one side of the first front disc 74 is the first air inlet 71, and the central through hole on one side of the second front disc 75 is the second air inlet 72. The double-suction impeller 7 uses 12 blades 76 evenly distributed around its circumference. A rear plate 73 is set between the first front plate 74 and the second front plate 75, dividing the double-suction impeller 7 into two parts. When the double-suction impeller 7 rotates, airflow enters from the first air inlet 71 and the second air inlet 72 at the same time. Then, both airflows flow out from the circumferential side of the double-suction impeller 7, which mixes the cold air and the hot air, and makes the temperature inside the heat treatment furnace drop evenly.

[0027] In this embodiment, there are 12 blades 76 distributed around the circumference, and the ratio of the distance from the rear plate 73 to the first front plate 74 to the distance from the rear plate 73 to the second front plate 75 is 1:2. The number of blades 76 is reasonable and moderate, which can improve the efficiency of the double suction impeller 7. The position of the cold air delivery on the double suction impeller 7 occupies one-third of the total area, which can make the cold air more fully mixed with the hot air in the furnace, so that the temperature in the heat treatment furnace drops gently and slowly, which meets the requirements of the temperature change curve in the heat treatment furnace, and reduces power consumption, vibration and noise.

[0028] In this embodiment, a cooling chamber 10 is arranged around the lowest bearing on the bearing housing 3. Water inlets 11 and outlets 12 are provided on opposite sides of the cooling chamber 10. The bearing housing 3 is equipped with water inlets 11 and outlets 12. When the fan is working, circulating water must be used to cool the bearing, ensuring that the inlet water temperature is below 35°C and the outlet water temperature is below 45°C.

[0029] The working process of this utility model is as follows:

[0030] As shown in Figures 1-4, firstly, the fixed plate 8 is installed on the top of the heat treatment furnace, the central shaft 17 is vertical, the heat insulation box 16 and the double suction impeller 7 extend into the heat treatment furnace. Then, when the fan is working, the variable frequency motor 1 starts and drives the central shaft 17 to rotate. The central shaft 17 drives the air-cooled wheel 4 and the double suction impeller 7 to rotate, so that cooling water is introduced into the cooling chamber 10 to cool the bearing at the lowest adjacent position. The airflow size is adjusted by rotating the adjusting plate 9 by adjusting the handle 13 and adjusting the overlapping position of the four adjusting holes 15 on the adjusting plate 9 and the air inlet hole 14 on the fixed plate 8.

[0031] The above embodiments are merely illustrative of the principles and effects of this utility model, as well as some of its applications, and are not intended to limit this utility model. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A heat-resistant circulating fan for cooling, characterized in that, The system includes a variable frequency motor (1), whose output shaft is connected to the upper end of a central shaft (17) via a coupling (2). The upper part of the central shaft (17) is housed in a bearing housing (3) via two separate bearings. The lower middle part of the central shaft (17) is inserted into a heat insulation box (16). A double suction impeller (7) is fitted on the lower end of the central shaft (17). The bottom of the heat insulation box (16) is connected to the first air inlet (71) at the top of the double suction impeller (7). The top circumference of the heat insulation box (16) is evenly distributed with multiple air inlets (14), and the bottom of the double suction impeller (7) is provided with a second air inlet (72). When the double suction impeller (7) rotates with the central shaft (17), it can draw the external airflow above the top of the heat insulation box (16) from the first air inlet (71) along the radial direction of the double suction impeller (7), and at the same time draw the hot air below the heat insulation box (16) from the second air inlet (72) along the radial direction of the double suction impeller (7).

2. The heat-resistant circulating fan for cooling according to claim 1, characterized in that, The top of the bearing housing (3) is fixed to the bottom of the variable frequency motor (1), and the bottom of the bearing housing (3) is fixed to the top of the heat insulation box (16). A cooling wheel (4) is fitted on the central shaft (17) near the lower end of the bearing housing (3). The cooling wheel (4) is located between the lowest bearing and the heat insulation box (16). Ventilation holes are left on the bearing housing (3) around the cooling wheel (4).

3. The heat-resistant circulating fan for cooling according to claim 1, characterized in that, The top of the heat insulation box (16) is set as a fixed plate (8), and four air inlets (14) are evenly distributed on the fixed plate (8). An adjustment plate (9) is set on the top of the fixed plate (8). The central through hole of the adjustment plate (9) is fitted on the bearing seat (3). Four adjustment holes (15) are evenly distributed on the annular circumferential surface of the adjustment plate (9). An adjustment handle (13) is set on the top of the adjustment plate (9). When the adjustment plate (9) is rotated by the adjustment handle (13), the overlapping position of the four adjustment holes (15) on the adjustment plate (9) and the air inlets (14) on the fixed plate (8) can be changed, thereby adjusting the airflow size.

4. The heat-resistant circulating fan for cooling according to claim 1 or 3, characterized in that, The side wall of the heat insulation box (16) is provided with heat insulation fiber cotton (5), and a horizontal perforated partition (6) is provided in the middle of the inner cavity of the heat insulation box (16).

5. The heat-resistant circulating fan for cooling according to claim 1, characterized in that, The double suction impeller (7) includes two annular and opposite first front discs (74) and second front discs (75). A flat rear disc (73) is arranged parallel to the opposite side of the first front discs (74) and the second front discs (75). The rear disc (73) is close to the side of the first front disc (74). Multiple blades (76) are connected to the opposite end faces of the first front discs (74) and the second front discs (75) and are distributed radially. The middle part of the blades (76) passes vertically through the rear disc (73). The two sides of the blades (76) are respectively vertically arranged on the opposite end faces of the first front discs (74) and the second front discs (75). The center of the rear disc (73) is a bushing (77). The central through hole on one side of the first front disc (74) is the first air inlet (71). The central through hole on one side of the second front disc (75) is the second air inlet (72).

6. The heat-resistant circulating fan for cooling according to claim 5, characterized in that, The blades (76) are distributed in 12 circumferences.

7. The heat-resistant circulating fan for cooling according to claim 1, characterized in that, The bearing housing (3) has a cooling chamber (10) arranged around the lowest bearing. The cooling chamber (10) has an inlet (11) and an outlet (12) on opposite sides.

8. The heat-resistant circulating fan for cooling according to claim 5, characterized in that, The ratio of the distance from the rear plate (73) to the first front plate (74) to the distance from the rear plate (73) to the second front plate (75) is 1:2.

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