Vacuum sintering furnace cooling system special for samarium-cobalt permanent magnet
By combining air cooling and water cooling in a vacuum sintering furnace for samarium cobalt permanent magnet materials, the problems of long cooling time and high power consumption of traditional cooling systems have been solved, achieving rapid cooling and performance improvement.
Patent Information
- Application Number
- CN202511482449.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-16
- Publication Date
- 2025-12-16
AI Technical Summary
Traditional samarium cobalt permanent magnet materials have long cooling times and high power consumption in their cooling systems, resulting in low product quality control and production efficiency.
Combining air cooling and water cooling, the system incorporates a water cooling component within the impeller assembly. A fan drives the impeller assembly to rotate, circulating the gas and cooling it through a heat exchanger. This achieves continuous and uniform forced air cooling of the product, while direct cooling is achieved through a circulating cooling water channel within the impeller assembly.
This technology significantly improves the cooling rate of samarium cobalt permanent magnet materials from 1200℃ to 80℃, reducing the cooling time to 30 minutes, thus enhancing magnetic properties and saving energy.
Smart Images
Figure CN121140431A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of sintering furnace cooling technology, and more specifically, to a vacuum sintering furnace cooling system for samarium cobalt permanent magnets. Background Technology
[0002] Samarium cobalt permanent magnets, as a high-performance permanent magnet, are widely used in aerospace, defense, precision instruments, and high-end motors due to their high energy product, high coercivity, and excellent thermal stability. Vacuum sintering is a crucial step in their fabrication process, as the sintering process and subsequent cooling rate and uniformity directly determine the microstructure, magnetic properties, and consistency of the final product.
[0003] Traditional cooling systems rely on fan motors to drive impeller assemblies for forced air cooling, and achieve gas circulation and heat dissipation through heat exchangers and annular heat exchange pipes. However, when relying solely on air cooling, the cooling rate is insufficient to meet the microstructural control requirements of high-performance samarium cobalt magnets. This results in excessively long cooling times from 1200°C to usable temperatures (approximately 80°C), which in turn increases equipment energy consumption and reduces product quality control and production efficiency. Summary of the Invention
[0004] 1. Technical problems to be solved The purpose of this invention is to provide a cooling system for a vacuum sintering furnace specifically for samarium cobalt permanent magnets, in order to solve the problems mentioned in the background art, such as long sintering furnace cooling time, high power consumption, and low product quality control and production efficiency.
[0005] 2. Technical Solution A cooling system for a vacuum sintering furnace specifically designed for samarium-cobalt permanent magnets includes a furnace body and further comprises: The air-cooled assembly includes a heat exchanger, a fan housing, a fan, an impeller assembly, and heat exchange pipes. The heat exchanger is connected to the furnace body and the fan housing through the heat exchange pipes to form a closed air duct. The fan is fixedly installed on the outside of the fan housing, and its power end extends into the inside of the fan housing through a power shaft and is fixedly connected to the impeller assembly to drive the impeller assembly to rotate, forcing the hot gas inside the furnace to flow through the heat exchange pipes and the heat exchanger for circulation and heat dissipation. Based on this, when the system starts the cooling process, the fan drives the power shaft and impeller assembly to rotate at high speed, generating a strong negative pressure inside the fan casing, which continuously extracts the high-temperature process gas from inside the furnace. The high-temperature gas is forced to flow through the annular heat exchange pipeline, where its heat is dissipated by the heat exchanger. The cooled gas is then transported back into the furnace, achieving continuous and uniform forced air cooling of the sintered products.
[0006] The water-cooled assembly includes a cooling water tank, a first water pump, a flow sleeve, a water storage tank, and a second water pump, which are connected in sequence by circulating water pipes. The flow sleeve is fixedly fitted on the outside of the fan and rotatably connected to the power shaft. The flow sleeve is connected to the internal water passage of the power shaft, and the internal water passage of the power shaft is further connected to the internal water channel of the impeller assembly, so that the cold water can circulate inside the impeller assembly and directly pass through the heat of the hot gas in the fan casing.
[0007] Preferably, the inner cavity of the flow sleeve is divided into an inlet annular groove and an outlet annular groove that are not interconnected. The outer wall of the flow sleeve is provided with an inlet that communicates with the inlet annular groove and an outlet that communicates with the outlet annular groove.
[0008] Based on this, the chilled water tank is responsible for precisely maintaining the cooling water temperature within a low-temperature range of 8°C. The flow sleeve is fixedly fitted onto the outside of the fan's drive motor and is rotatably connected to the high-speed rotating power shaft via a high-performance rotary seal. This flow sleeve is a key transitional component connecting the static pipeline and the rotating shaft; its internal cavity is precisely divided into two completely independent, non-communicating annular channels: an inlet annular channel and an outlet annular channel. On the outer wall of the flow sleeve, an inlet communicating with the inlet annular channel and an outlet communicating with the outlet annular channel are machined, respectively, for connecting to the external circulating water pipeline.
[0009] Preferably, the power shaft is internally provided with an inlet pipe and an outlet pipe. One end of the inlet pipe is connected to the inlet annular groove, and the other end of the inlet pipe is connected to the inlet end of the impeller assembly. One end of the outlet pipe is connected to the outlet end of the impeller assembly, and the other end of the outlet pipe is connected to the outlet annular groove of the flow sleeve.
[0010] Based on this, one end of the inlet pipe connects to the inlet annular groove of the flow sleeve via a rotary interface, while the other end extends into the fan casing, precisely connecting to the inlet end of the impeller assembly. The outlet pipe connects to the outlet end of the impeller assembly at one end and to the outlet annular groove of the flow sleeve at the other. This built-in water system ensures that cooling water can be seamlessly transferred from the static external circulation system to the high-speed rotating impeller core.
[0011] Preferably, the impeller assembly includes a front disc, a rear disc, and a plurality of connecting water channels between the front disc and the rear disc, wherein the front disc, the rear disc, and the connecting water channels together constitute the cooling flow channel inside the impeller.
[0012] Preferably, the water inlet end of the internal water channel of the impeller assembly is located outside the front plate and connected to the water inlet pipe, and the water outlet end of the internal water channel of the impeller assembly is located outside the rear plate and connected to the water outlet pipe.
[0013] Preferably, the outer surface of the front disc is a conical structure, and the front disc, rear disc, and connecting water channel are all made of a high thermal conductivity metal material.
[0014] Based on this, as a preferred enhancement design, the outer surface of the front disc is designed with a tapered surface structure. This streamlined design not only reduces airflow resistance and improves air-cooling efficiency, but also increases the contact area with high-temperature gases, further enhancing the heat dissipation effect.
[0015] Preferably, the cold water flows sequentially from the cooling water tank through the first water pump, the circulating water pipe, the inlet of the flow sleeve, the inlet annular groove, the inlet pipe of the power shaft, the internal water channel of the impeller assembly, the outlet pipe of the power shaft, the outlet annular groove of the flow sleeve, the outlet, the circulating water pipe, the water storage tank, and the second water pump back to the cooling water tank.
[0016] Based on this, the complete circulation path of the low-temperature cooling water during system operation is as follows: Cold water starts from the refrigeration water tank, powered by the first water pump, and is pumped into the inlet of the flow sleeve through the circulating water pipe; then it flows into the inlet annular groove and enters the inlet pipe inside the high-speed rotating power shaft through the rotary interface; the cooling water flows axially to the impeller assembly, and enters the internal cooling channel composed of the front plate, rear plate, and connecting water channel from its inlet end. During the flow of water in the channel, it fully absorbs a large amount of heat transferred to the impeller metal parts by the gas. The cooling water, after absorbing heat and heating up, flows out from the outlet end of the impeller, enters the outlet pipe of the power shaft, and flows back in the opposite direction to the outlet annular groove of the flow sleeve; finally, the warm water is discharged through the outlet, flows into the storage tank through the circulating water pipe for temporary storage and preliminary sedimentation, and is finally pumped back to the refrigeration water tank by the second water pump for cooling and regeneration, thus forming a complete, closed-loop, ultra-efficient cooling cycle.
[0017] 3. Beneficial effects: Compared with the prior art, the advantages of the present invention are as follows: This invention is based on the traditional gas circulation path of a fan motor-driven impeller, maintaining efficient air heat exchange in the heat exchange pipeline, and adding an external water-cooling component. At the same time, the "water-cooling" structure is cleverly integrated into the "air-cooled" impeller assembly. Cold water is injected into the internal water channel of the impeller through a circulating water pipe. Combining the "air-cooling" and "water-cooling" cooling methods, the cold water circulates inside the impeller assembly, removes heat, and achieves circulating cooling and rapid temperature reduction. This allows a 200 kg batch of product to be cooled from 1200°C to 80°C in just 30 minutes, greatly improving the cooling speed. Furthermore, the coercivity HCJ of the samarium cobalt permanent magnet increases from 25 KOe to 30 KOe, saving energy while improving product performance. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the fan casing of the present invention; Figure 3 This is a schematic diagram of the water-cooling component structure of the present invention; Figure 4 This is a schematic diagram of the connection structure between the fan and the impeller assembly of the present invention; Figure 5 This is a schematic diagram of the connection structure between the front disc of the impeller assembly and the connecting waterway of the present invention; Figure 6 This is a schematic diagram of the connection structure between the impeller assembly rear disc and the connecting waterway of the present invention; Figure 7 This is a schematic diagram of the water flow direction during water cooling of the impeller assembly of the present invention; Figure 8 This is a schematic diagram of the samarium cobalt permanent magnet heating structure of the furnace body of the present invention; Figure 9 This is a schematic diagram of the second (1) modified scheme for connecting waterways of the present invention; Figure 10 This is a schematic diagram of the second (2) modification scheme for connecting waterways in this invention.
[0019] Explanation of the numbers in the diagram: 1-Furnace body, 101-Graphite floor, 102-Molybdenum column, 103-Graphite, 104-Insulation cotton, 2-Power regulator, 3-Electrical control cabinet, 4-Mechanical pump, 5-Roots pump, 6-Pressure regulating pipe, 7-Slide valve, 8-Heat exchanger, 9-Fan casing, 10-Fan, 11-Heat exchange piping, 12-Water cooling assembly, 1201-Refrigeration water tank, 1202-Water storage tank, 1203-Water pump one, 1 204-Water Pump II, 1205-Circulating Water Pipe, 13-Power Shaft, 1301-Inlet Pipe, 1302-Outlet Pipe, 14-Flow Sleeve, 1401-Inlet Annular Groove, 1402-Outlet Annular Groove, 1403-Inlet, 1404-Outlet, 15-Impeller Assembly, 1501-Front Plate, 1502-Rear Plate, 1503-Connecting Water Channel, 1504-Notch, 1505-Arc-shaped Heat Conducting Plate. Detailed Implementation
[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0021] In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. It should be noted that, unless otherwise explicitly specified and limited, terms such as "installed," "equipped with," "sleeved / connected," and "connected" should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0022] Please see Figure 1-10 A cooling system for a vacuum sintering furnace specifically designed for samarium-cobalt permanent magnets, wherein the furnace body 1 serves as the core heating container, and its power is precisely controlled by a power regulator 2. (See attached instruction manual for details.) Figure 8 As shown, the system also includes a product-bearing assembly installed inside the furnace body 1. This assembly includes a graphite base plate 101 for holding the samarium cobalt permanent magnet green product blank. The graphite base plate 101 is supported and installed inside the furnace body 1 by a vertical molybdenum column 102 at the bottom. Graphite elements are arranged around the furnace body 1 to act as heating elements and are electrically connected to an external power regulator 2, converting the electrical energy of the power regulator 2 into heat energy to heat the product. Insulation cotton 104 is also installed on the inner wall of the furnace body 1 to prevent heat loss. The control center of the entire system is the electrical control cabinet 3, which coordinates the operation of each component. The establishment of the vacuum environment is accomplished by a vacuum unit consisting of a mechanical pump 4 and a Roots pump 5. A pressure regulating pipe 6 and a slide valve 7 are provided on the vacuum pipeline for adjusting and cutting off the furnace vacuum. The above structures are conventional in the field, and their specific connection methods and workflows will not be elaborated upon further.
[0023] In the cooling section, the air-cooled assembly and the water-cooled assembly 12 work together to rapidly cool the furnace body 1. The air-cooled assembly includes a heat exchanger 8, a fan housing 9, a fan 10, an impeller assembly 15, and heat exchange pipes 11. The heat exchanger 8 is connected to the furnace body 1 and the fan housing 9 through the annular heat exchange pipes 11, forming a closed gas circulation channel. The fan 10 is fixedly installed on the outside of the fan housing 9 via a flange, and its drive shaft 13 extends into the inside of the fan housing 9 and is fixed to the center of the impeller assembly 15. The electrical control cabinet 3 controls the fan 10 to start, driving the impeller assembly 15 to rotate at high speed, thereby extracting the high-temperature gas from the furnace body 1 and forcing the gas to flow through the heat exchange pipes 11 into the heat exchanger 8 for heat exchange. The cooled gas is then transported back into the furnace body 1, realizing forced air-cooling circulation.
[0024] The water-cooled assembly 12 consists of a cooling water tank 1201, a water storage tank 1202, a first water pump 1203, a second water pump 1204, a circulating water pipe 1205, and a flow sleeve 14 integrated on the fan 10 and the internal water passage of the power shaft 13. The cooling water tank 1201 maintains the cold water temperature at 0-5℃. During cooling, the cold water is first pumped out of the cooling water tank 1201 by the first water pump 1203, and then transported through the circulating water pipe 1205 to the inlet 1403 of the flow sleeve 14 on the outside of the power shaft 13. After entering the inlet annular groove 1401 of the flow sleeve 14, the cold water flows axially into the high-speed rotating impeller assembly 15 through the inlet pipe 1301 inside the power shaft 13. The impeller assembly 15 consists of a front disc 1501, a rear disc 1502, and a connecting water channel 1503. All three are made of high thermal conductivity materials such as copper alloy, forming a closed cooling channel. During the flow of cold water inside the impeller assembly 15, the hot air in the fan casing 9 transfers heat to the internal cold water through the impeller 15. The heated cold water flows axially out through the outlet pipe 1302 of the power shaft 13, enters the outlet annular groove 1402 of the flow sleeve 14, and finally flows back to the water storage tank 1202 from the outlet 1404 through the circulating water pipe 1205. After preliminary sedimentation in the water storage tank 1202, the returned high-temperature cold water is pumped back to the cooling water tank 1201 by the second water pump 1204 for recooling, forming a complete closed-loop cooling cycle.
[0025] Working principle: After the sintering process is completed, the system starts the cooling program. The electrical control cabinet 3 simultaneously starts the first water pump 1203 and the second water pump 1204 of the fan 10 and water cooling component 12. The air cooling component starts to circulate the gas in the furnace and performs initial heat dissipation through the heat exchanger 8. At the same time, cold water is injected into the core of the high-speed rotating impeller component 15 to directly dissipate the high temperature liquid in the fan casing 9. It can also dissipate heat from the fan 10 after long-term use, which greatly improves the heat exchange efficiency of the entire system. Finally, it achieves the rapid cooling effect of reducing 200 kg of material from 1200℃ to 80℃ in only about 30 minutes, and significantly improves the magnetic properties of the product.
[0026] Based on the above scheme, in actual use, the operator can choose from the following scheme according to actual needs and cost expenditures. The following scheme is Scheme Two, and the connecting waterway 1503 in the above scheme is optimized. (See attached instruction manual.) Figure 9-10 Option 2 aims to increase the contact surface between the connecting water channel 1503 and the internal hot airflow of the fan casing 9, thereby enabling the connecting water channel 1503 to achieve more efficient heat exchange and facilitating the rapid removal of heat from the fan casing 9 by water cooling. (See attached instruction manual.) Figure 9As shown, in the second scheme (1), to further enhance heat dissipation, several notches 1504 are opened at the outer edge of a specific flow guide surface of the fan-shaped connecting water channel 1503, and a matching arc-shaped heat-conducting plate 1505 is welded to the outside of each notch 1504. This design constitutes a secondary extended heat dissipation surface. The arc-shaped heat-conducting plate 1505 further increases the surface area in contact with air, while its arc shape helps to reduce wind resistance and ensure that the airflow can flow smoothly and efficiently over each heat dissipation surface.
[0027] Among them, as shown in the instruction manual Figure 10 As shown, in the second scheme (2), to further enhance heat dissipation, the main body of the connecting water channel 1503 is designed with radially distributed fan blades. The fan blade structure itself constitutes multiple independent airflow guiding surfaces, which not only greatly increases the effective heat dissipation area of the water channel body, but also enables it to actively stir and guide airflow during system operation, destroying the thermal boundary layer of the air, thus combining the disturbance function of air-cooled fan blades and realizing the initial synergy between passive air cooling and water cooling.
[0028] Based on this, it is also necessary to add that Scheme 2 (1) and Scheme 2 (2) can also be combined. A certain gap 1504 can be selectively opened on the outside of the connecting water channel 1503 of the fan blade shape and an arc-shaped heat-conducting plate 1505 can be welded. In this way, the effects of both can be achieved at the same time, and the overall heat dissipation performance can be improved.
[0029] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.
Claims
1. A cooling system for a vacuum sintering furnace specifically for samarium-cobalt permanent magnets, comprising a furnace body (1), characterized in that: Also includes: The air-cooled assembly includes a heat exchanger (8), a fan housing (9), a fan (10), an impeller assembly (15), and a heat exchange pipeline (11). The heat exchanger (8) is connected to the furnace body (1) and the fan housing (9) through the heat exchange pipeline (11) to form a closed air duct. The fan (10) is fixedly installed on the outside of the fan housing (9). Its power end extends into the fan housing (9) through a power shaft (13) and is fixedly connected to the impeller assembly (15) to drive the impeller assembly (15) to rotate, forcing the hot gas in the furnace body (1) to flow through the heat exchange pipeline (11) and the heat exchanger (8) for circulating heat dissipation. The water-cooled assembly (12) includes a cooling water tank (1201), a first water pump (1203), a flow sleeve (14), a water storage tank (1202), and a second water pump (1204) connected in sequence through a circulating water pipe (1205). The flow sleeve (14) is fixedly sleeved on the outside of the fan (10) and rotatably connected to the power shaft (13). The flow sleeve (14) is connected to the water passage inside the power shaft (13). The water passage inside the power shaft (13) is further connected to the water channel inside the impeller assembly (15), so that the cold water can circulate inside the impeller assembly (15) and directly pass through the heat of the hot gas in the fan casing (9).
2. The cooling system for a samarium-cobalt permanent magnet vacuum sintering furnace according to claim 1, characterized in that: The inner cavity of the flow sleeve (14) is divided into an inlet annular groove (1401) and an outlet annular groove (1402) that are not connected to each other. The outer wall of the flow sleeve (14) is provided with an inlet (1403) that communicates with the inlet annular groove (1401) and an outlet (1404) that communicates with the outlet annular groove (1402).
3. The cooling system for a samarium-cobalt permanent magnet vacuum sintering furnace according to claim 2, characterized in that: The power shaft (13) is equipped with an inlet pipe (1301) and an outlet pipe (1302). One end of the inlet pipe (1301) is connected to the inlet annular groove (1401), and the other end of the inlet pipe (1301) is connected to the inlet end of the impeller assembly (15). One end of the outlet pipe (1302) is connected to the outlet end of the impeller assembly (15), and the other end of the outlet pipe (1302) is connected to the outlet annular groove (1402) of the flow sleeve (14).
4. The cooling system for a samarium-cobalt permanent magnet vacuum sintering furnace according to claim 3, characterized in that: The impeller assembly (15) includes a front plate (1501), a rear plate (1502), and a plurality of connecting water channels (1503) connecting the front plate (1501) and the rear plate (1502). The front plate (1501), the rear plate (1502), and the connecting water channels (1503) together constitute the cooling flow channel inside the impeller.
5. The cooling system for a samarium-cobalt permanent magnet vacuum sintering furnace according to claim 4, characterized in that: The water inlet end of the internal water channel of the impeller assembly (15) is located outside the front plate (1501) and is connected to the water inlet pipe (1301). The water outlet end of the internal water channel of the impeller assembly (15) is located outside the rear plate (1502) and is connected to the water outlet pipe (1302).
6. The cooling system for a samarium-cobalt permanent magnet vacuum sintering furnace according to claim 5, characterized in that: The outer surface of the front disc (1501) is a conical structure, and the front disc (1501), the rear disc (1502), and the connecting water channel (1503) are all made of high thermal conductivity metal material.
7. The cooling system for a samarium-cobalt permanent magnet vacuum sintering furnace according to claim 6, characterized in that: The cold water flows sequentially from the cooling water tank (1201) through the first water pump (1203), the circulating water pipe (1205), the inlet (1403) of the flow sleeve (14), the inlet annular groove (1401), the inlet pipe (1301) of the power shaft (13), the internal water channel of the impeller assembly (15), the outlet pipe (1302) of the power shaft (13), the outlet annular groove (1402) of the flow sleeve (14), the outlet (1404), the circulating water pipe (1205), the water storage tank (1202), and the second water pump (1204) back to the cooling water tank (1201).