Degreasing sintering furnace and cooling method

Abstract

The invention discloses a degreasing sintering furnace and a cooling method, relates to the field of heat treatment equipment, and adopts the technical scheme that the degreasing sintering furnace comprises a cooling device independently arranged outside a furnace body. The cooling device is internally provided with an independent cooling air duct, a blower device used for driving gas circulation and a liquid cooling mechanism used for forced cooling. And a blowpipe for supplying inert gas is also arranged in the hearth. According to the invention, through an independent external liquid cooling forced cooling mode with extremely high heat transfer efficiency, wide-range cooling control from limit rapid cooling to precise slow cooling is realized. And moreover, the cooling time and the production period are greatly shortened, and the production efficiency and the process adaptability of equipment are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of heat treatment equipment, and in particular to a degreasing sintering furnace and a cooling method. Background Technology

[0002] In modern materials processing and heat treatment, such as metal powder sintering, annealing or solution treatment of precision parts, the cooling process after high-temperature treatment is a crucial step that determines the performance and quality of the final product. The cooling rate not only directly affects the microstructure and macroscopic mechanical properties of the material, but the ambient gas during the cooling process also plays a decisive role in the surface condition and chemical stability of the product.

[0003] Currently, the most common cooling method used in the industry is to directly utilize the inherent hot air circulation system within the heat treatment furnace for cooling. The specific operation is as follows: after completing the high-temperature heating or holding stage, the power supply to the heating elements is stopped, but the circulating fan continues to operate. The fan drives the gas inside the furnace to circulate continuously, forcing the gas to pass over the surface of the high-temperature workpiece, thereby accelerating the cooling process.

[0004] However, this method of utilizing a heating circulation system for both heating and cooling has revealed several inherent technical flaws in practice. Firstly, its cooling efficiency is far from meeting the demands of high-efficiency, high-cycle production. The core design principle of a heat treatment furnace is efficient heating and precise temperature control; therefore, the furnace body itself is a highly insulated structure, designed to minimize heat loss rather than efficiently remove heat. After the heat source is shut off, relying solely on internal gas circulation results in low overall heat exchange efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a degreasing sintering furnace, which aims to solve the technical problems of low cooling efficiency and uncontrollable cooling rate in the prior art.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A degreasing sintering furnace, comprising: The furnace body has a furnace chamber inside; A hot air circulation duct is connected to the furnace to form a heating circulation path; Both the air source and the heat source are located in the hot air circulation duct. The air source is used to drive the gas to flow through the heat source to heat the furnace. Also includes: A cooling device is located outside the furnace body. The cooling device has a cooling air duct that is connected to the furnace to form an independent cooling circulation path. A blower device is installed inside the cooling air duct to drive the gas in the furnace to flow in the cooling circulation path; A liquid cooling mechanism, which is disposed in the cooling air duct, is used to cool the gas flowing through it; An inert gas supply system includes a blower pipe located inside the furnace and an inert gas source for supplying inert gas to the blower pipe; the inert gas supply system ensures that the cooling process of the furnace is carried out under inert gas conditions.

[0007] Further configuration: The cooling air duct includes: The external air duct is located within the cooling device; The connecting air duct and the blowing air duct are located at the bottom of the furnace. The external air duct, the connecting air duct and the blowing air duct are connected in sequence. There are two blowing air ducts. The two blowing air ducts are respectively arranged along the opposite inner walls of the furnace and have multiple first blowing ports facing the inside of the furnace.

[0008] Further configuration: A second air outlet is also provided on the connecting air duct, and the airflow path from the second air outlet is perpendicular to the airflow path from the first air outlet.

[0009] Further configuration: The heat circulation duct also includes: An extended air duct located in the bottom area of ​​the furnace; At least one injection unit is located in the side wall region of the furnace; wherein each injection unit consists of four injection pipes, and the four injection pipes have different injection directions.

[0010] Further configuration: The cooling device includes: The housing, in which the blower and liquid cooling mechanism are both housed; The air inlet pipe and the air outlet pipe connect the shell and the furnace to form the cooling air duct. Valves are provided on the air inlet pipe and the air outlet pipe respectively. A flow guide is disposed inside the housing, and the flow guide is used to guide the gas to flow evenly across the surface of the liquid cooling mechanism; A rotating device and a transmission mechanism, wherein the transmission mechanism connects the rotating device and the blower to drive the blower to rotate.

[0011] Further configuration: The air guide includes: a first air guide plate and a second air guide plate arranged in a grid pattern, which are spaced apart within the housing; a first space is formed between the first air guide plate and the second air guide plate, and the air inlet pipe is connected to the first space; a second space is formed between the first air guide plate and the top wall of the housing; An arc-shaped guide vane extends from one end to the first space and the other to the second space.

[0012] Further configuration: The liquid cooling mechanism includes: support; The disc-shaped tube is mounted on the support. An inlet pipe and an outlet pipe; one end of a disc-shaped tube is connected to the inlet pipe, and the other end is connected to the outlet pipe; the inlet pipe and the outlet pipe are respectively provided with an inlet and an outlet; An external circulating water source is connected to both the inlet and outlet.

[0013] Further configuration: The disc-shaped tube is composed of at least one U-shaped tube; Each U-shaped tube has at least three bends to form multiple tube segments extending in the horizontal direction; and the U-shaped tube is inclined in the vertical direction so that the multiple tube segments form a preset inclination angle.

[0014] Further configuration: It also includes at least one cooling unit, each cooling unit consisting of two liquid cooling mechanisms arranged vertically; in each cooling unit, one of the liquid cooling mechanisms has a U-shaped tube with a sandwich layer formed by sealing and covering with metal material on the outer wall of at least one tube section, and the sandwich layer is filled with phase change energy storage material.

[0015] Another object of the present invention is to provide a cooling method for a degreasing sintering furnace as described above, comprising the following steps: S1: Perform cooling preparation steps; S11: Stop the operation of the hot air circulation duct, the steps of which include stopping the heating of the heat source and stopping the operation of the air source; S12: Inert gas is supplied into the furnace through an inert gas supply system to perform the cooling step in an inert gas environment; S2: Perform the cooling step: S21: Start the blower in the cooling device to drive the gas in the furnace into an independent cooling circulation path; S22: Allows the gas flowing in the cooling cycle path to be cooled by passing through the liquid cooling mechanism; S23: The cooled low-temperature gas is sent back to the furnace and continuously circulated in a closed loop until the furnace temperature drops to the preset value.

[0016] In summary, the present invention has the following beneficial effects: First, this invention employs an external, independently driven liquid cooling mechanism for forced cooling, a highly efficient heat transfer method. By precisely controlling the speed of the blower and the coolant flow rate of the liquid cooling mechanism, a wide range of non-linear programmed cooling control, from extreme rapid cooling to precise slow cooling, can be achieved. This allows users to precisely control the supercooling and phase change process of different materials according to their process requirements, thereby actively regulating their final microstructure and mechanical properties, greatly expanding the equipment's process adaptability and application areas. Furthermore, this solution, through highly efficient liquid-cooled forced convection heat transfer, has a heat dissipation capacity exceeding that of internal circulation air cooling, reducing cooling time by several times. The significant reduction in production cycle time means a substantial increase in output per unit time for a single unit, which directly translates into significant economic benefits in large-scale production.

[0017] Secondly, this invention eliminates the risk of condensation, ensuring a dry environment for the cooling process. During forced cooling, when hot, humid gas encounters the low-temperature surface of the liquid cooling mechanism, condensation easily occurs due to the temperature being below the dew point, leading to equipment corrosion and workpiece contamination. This solution's independent cooling circuit works in conjunction with a dedicated inert gas supply system, ensuring that the cooling medium participating in the circulation is a high-purity inert gas with a very low dew point, after being replaced. This physically prevents condensation from forming throughout the entire cooling range, providing an absolutely dry cooling environment for the workpiece and avoiding potential quality risks such as oxidation or hydrogen embrittlement caused by moisture.

[0018] Third, in this invention, by introducing cooling gas from the bottom of the furnace, the physical principle that cold gas has a higher density and hot gas has a lower density is utilized. This allows the cooling airflow to form a stable, bottom-up, and naturally convective overall displacement flow after being heated, avoiding the problem of overcooling at the top and insufficient cooling at the bottom caused by gas stratification. This ensures that the workpiece receives uniform cooling throughout its entire height. By symmetrically supplying air through two air ducts arranged along the opposite inner walls of the furnace, the two opposing cold airflows converge and collide in the central area of ​​the furnace, generating controllable turbulence and forming a uniform upward airflow field. This completely eliminates the temperature difference between the yin and yang sides of the workpiece caused by unilateral air supply. At the same time, the enhanced turbulence improves the convective heat transfer efficiency, achieving rapid and uniform cooling of the workpiece within its cross-section.

[0019] Fourth, in this invention, by combining an extended air duct at the bottom of the furnace with a multi-directional injection unit on the side wall, the main hot airflow from bottom to top and the auxiliary hot airflow injected from the side wall with multiple different vector directions undergo thorough three-dimensional mixing and momentum exchange within the furnace. This forms a uniform, fully dynamic thermal field without a clear flow main line, effectively eliminating the heat shadow effect caused by mutual obstruction of workpieces and ensuring a highly consistent heating rate for the entire furnace product on a macroscopic scale. By using an injection unit composed of four injection pipes with different injection directions, tangential airflows with varying directions are continuously and alternately generated in different local areas near the workpiece surface. This continuously and forcibly disrupts the static gas boundary layer attached to the workpiece surface, greatly enhancing the convective heat transfer coefficient and significantly improving the efficiency of heat transfer from the gas to the workpiece, achieving a faster heating rate.

[0020] Fifth, in this invention, by connecting the air inlet pipe to the first space formed by the first guide plate and the second guide plate, and the first guide plate and the top wall of the shell having a second space, the first space and the second space having arc-shaped guide plates, together forming an extended space; by utilizing the deceleration and pressurization principle of the fluid after entering the extended space, the high-speed jet at the inlet is transformed into a stable flow pressurization chamber with uniform pressure and slow flow velocity, and the flow field is initially homogenized by the second layer of grid-like guide plates, eliminating the flow field non-uniformity caused by the inlet jet effect from the source, and providing ideal and stable inlet conditions for subsequent precise flow guidance and uniform heat exchange.

[0021] Sixth, in this invention, by bending the U-shaped tube at least three times to form multiple compactly arranged horizontal tube segments, the effective contact length and heat exchange area between the coolant flow channel and the external gas are greatly increased within a limited single-layer space, achieving high-density heat exchange capacity, so that the liquid cooling mechanism can provide powerful cooling power while maintaining a compact structure.

[0022] By tilting the horizontally extending U-shaped tube vertically, the cooling gas flowing upwards through the liquid cooling mechanism is unobstructed in the longitudinal direction. This creates a straight, open airflow channel with low flow resistance in the longitudinal dimension of the furnace body, significantly reducing airflow turbulence and pressure pulsation. Ultimately, this improves the overall cooling rate while reducing system operating noise and energy consumption.

[0023] Seventh, in this invention, each cooling unit consists of two liquid cooling mechanisms arranged vertically. In each cooling unit, one of the liquid cooling mechanisms has a U-shaped tube with a sandwich layer formed by sealing and covering it with a metal material on the outer wall of at least one section. The sandwich layer is filled with a phase change energy storage material. Under continuous and constant heat flow, the U-shaped tube without a phase change layer has higher instantaneous heat dissipation efficiency. However, under conditions of heat flow fluctuations or thermal shock, the system with a phase change energy storage material layer performs more stably and is more controllable, capable of handling higher peak heat loads.

[0024] When a powerful heat flow suddenly impacts the U-shaped tube, the phase change material layer immediately begins to melt. During melting, it absorbs a significant amount of latent heat, but its own temperature stabilizes near its melting point. This means that no matter how intense the external heat flow, the temperature transferred to the surface of the internal U-shaped tube is kept within the melting point of the phase change material, preventing a rapid temperature spike. The water inside the U-shaped tube can exchange heat calmly and with a relatively constant temperature difference, without being subject to sudden peak heat loads that could cause localized instantaneous boiling or temperature runaway. Once the external heat flow peak has passed, the molten phase change material stores a large amount of thermal energy.

[0025] The U-shaped tube in the other liquid cooling mechanism provides the most direct and lowest thermal resistance heat transfer path. It can start efficient heat dissipation immediately, with a high heat dissipation rate and instantaneous response. The moment the high-temperature gas comes into contact with the U-shaped tube, the heat begins to be carried away by the water inside the tube, and the heat dissipation process starts at full power immediately.

[0026] The synergistic effect of these two factors allows the cooling device to operate without sacrificing its overall heat dissipation rate to cope with short-term peak loads. This achieves the fastest overall cooling speed while ensuring absolute safety and reliability, thus resolving the technical contradiction between heat dissipation speed and operational stability. Attached Figure Description

[0027] Figure 1 This is a three-dimensional structural diagram of a degreasing sintering furnace; Figure 2 This is a schematic diagram of the longitudinal section of the degreasing sintering furnace; Figure 3 This is a schematic diagram of the cross-section of a degreasing sintering furnace; Figure 4 This is a schematic diagram of the cooling air duct structure; Figure 5 This is a schematic diagram of the structure of a heat circulation air duct; Figure 6 This is a schematic diagram of the cooling device. Figure 7 This is a schematic diagram of the longitudinal section of the cooling device; Figure 8 This is a schematic diagram of the liquid cooling mechanism.

[0028] In the diagram, 100 is the furnace body; 101 is the furnace chamber; and 102 is the air duct. 110. Hot air circulation duct; 111. Jet pipe; 112. Extension duct; 200. Cooling device; 201. Housing; 202. Air inlet pipe; 203. Air outlet pipe; 204. Blower; 205. Rotating device; 206. Transmission mechanism; 207. Valve; 208. Flow guide; 209a. First flow guide plate; 209b. Second flow guide plate; 209c. Arc-shaped flow guide plate; 210. Cooling air duct; 211. External air duct; 212. Connecting air duct; 213. Air blowing duct; 214. First air outlet; 215. Second air outlet; 220. Liquid cooling mechanism; 221. Support frame; 222. Liquid outlet pipe; 223. Liquid outlet; 224. Liquid inlet pipe; 225. Liquid inlet; 226. Coiled tube; 227. Jacket; 300, air source; 400, heat source. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings.

[0030] 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," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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.

[0031] This embodiment provides a degreasing sintering furnace, such as Figure 1 , Figure 2 and Figure 3 As shown, it includes a furnace body 100, and a heat circulation system and a cooling system connected to the furnace body 100. The furnace body 100 has a furnace chamber 101 for accommodating and processing workpieces, and the furnace chamber 101 is a closed working space for heat treatment.

[0032] The thermal circulation system is used to heat and maintain the temperature of the furnace 101. It includes a thermal circulation duct 110, which connects the upper and lower parts of the furnace 101, thus forming a closed heating circulation path. Inside the thermal circulation duct 110, an air source 300 and a heat source 400 are arranged along the gas flow direction. The air source 300 provides the power for gas circulation and can be a high-temperature resistant centrifugal fan or axial fan. The heat source 400 follows immediately after the air source 300 and is used to heat the circulating gas. It can be an electric heating element group composed of resistance wire or silicon carbide rods, or other forms of heating devices such as a gas burner.

[0033] The cooling system is used to force the workpiece to cool down after heat treatment. It includes a cooling device 200 that is independently installed outside the furnace body 100. The cooling device 200 has a cooling air duct 210 inside, which is connected to the working space of the furnace chamber 101 through inlet and outlet pipes to form an independent cooling circulation path.

[0034] Within the cooling air duct 210 of the cooling device 200, a blower 204 and a liquid cooling mechanism 220 are installed. The blower 204 is the main power source for the cooling cycle, used to drive the gas in the furnace 101 to flow at high speed in the cooling cycle path; specifically, it can be a high-power centrifugal blower. The liquid cooling mechanism 220 is located downstream of the airflow from the blower 204, used to forcibly and efficiently cool the flowing high-temperature gas; specifically, it can be a water-cooled or oil-cooled heat exchanger, such as a compact finned tube heat exchanger or a plate heat exchanger with a large heat exchange area.

[0035] In addition, this degreasing sintering furnace also includes an inert gas supply system. The system includes an inert gas source and a blower 102 connected to the inert gas source. The inert gas source can be a liquid argon Dewar flask, a high-pressure argon cylinder group, or an on-site nitrogen generator. The blower 102 is located at a predetermined position inside the furnace chamber 101, and its surface can be provided with multiple openings for uniformly supplying pure, dry inert gas into the furnace chamber 101 to create and maintain the required gaseous environment during the specified process stage.

[0036] like Figure 4 As shown, in this embodiment, the cooling air duct 210 includes an external air duct 211 located inside the cooling device 200, and an internal air duct extending into the furnace 101. The internal air duct includes a connecting air duct 212 and one or more blowing air ducts 213.

[0037] The external air duct 211 houses the blower 204 and the liquid cooling mechanism 220, and its outlet end is connected to the connecting air duct 212. The connecting air duct 212 is located in the bottom area of ​​the furnace 101, serving as a buffer and distribution chamber for the cooling gas after it enters the furnace 101.

[0038] In this embodiment, two air-blowing ducts 213 extend from the two opposite sides of the connecting air duct 212. The two air-blowing ducts 213 are symmetrically arranged and are laid out along the roots of the two opposite inner walls at the bottom of the furnace 101, parallel to the length direction of the furnace body 100. On the side wall of each air-blowing duct 213 facing the center of the furnace 101, a plurality of first air-blowing nozzles 214 are provided. The first air-blowing nozzles 214 can be small circular or square holes evenly distributed along the length direction of the air-blowing duct 213, or nozzles with a specific flow guiding angle, used to blow cooling gas toward the working area at the center of the furnace 101.

[0039] As a further feature of the internal air duct, a second air outlet 215 is provided on the connecting air duct 212. The second air outlet 215 is located at the bottom of the furnace 101, at the center between the two aforementioned air ducts 213, and its opening faces horizontally inward. This ensures that the gas blown out of the second air outlet 215 initially flows along a horizontal airflow path from the outside inward along its length. In contrast, the gas blown out of the first air outlet 214, which is located on the inner wall of the air duct 213, initially flows along a horizontal path converging from both sides of the furnace 101 towards the center. Therefore, the horizontal airflow path along the length of the furnace 101 blown out from the bottom center region and the horizontal airflow paths along the width direction blown out from both sides form a mutually perpendicular configuration in the plane. The second air outlet 215 can be a single large rectangular or circular opening, or an array of multiple small openings.

[0040] like Figure 5 As shown, in order to form a uniform heating gas environment inside the furnace 101, the hot circulation duct 110 further includes an extended duct 112 located in the bottom region of the furnace 101, and one or more injection units disposed in the side wall region of the furnace 101.

[0041] The extended air duct 112 is directly connected to the hot circulation air duct 110 and is arranged along the bottom area of ​​the furnace 101. The extended air duct 112 can be an open, flat pipe.

[0042] The injection units are disposed on one or more side walls of the furnace 101 and connected to the hot air circulation duct 110. In one specific embodiment, each injection unit consists of four independent injection pipes 111. The injection axes of these four injection pipes 111 are oriented differently from each other to create multi-dimensional turbulent airflow in a local area. For example, within an injection unit, one injection pipe 111 may be horizontally oriented towards the center of the furnace 101, one may be tilted to the upper left, one may be tilted to the lower right, and another may point towards the front or rear of the furnace 101. This multi-directional injection layout is used to inject high-temperature gas into the working area within the furnace 101 at multiple angles and in multiple layers.

[0043] like Figure 6 , Figure 7 and Figure 8 As shown, the cooling device 200 is an independent, integrated modular unit, the main body of which is a sealed shell 201. The shell 201 can be a cylindrical or square container, on which an air inlet pipe 202 and an air outlet pipe 203 are provided for connecting to the furnace 101. For example, the air inlet pipe 202 can communicate with the top of the shell 201, while the air outlet pipe 203 can be led out from the lower side of the shell 201. Both the air inlet pipe 202 and the air outlet pipe 203 extend through pipes and connect to a pre-set interface of the furnace 101. Valves 207 are installed on the air inlet pipe 202 and the air outlet pipe 203 to physically isolate the cooling device 200 from the furnace 101 during the non-cooling stage. These valves 207 can be pneumatic or electric butterfly valves 207 or gate valves 207.

[0044] Inside the housing 201, along the gas flow path from the inlet pipe 202 to the outlet pipe 203, a flow guide 208, a liquid cooling mechanism 220, and a blower 204 are sequentially arranged. The flow guide 208 is located downstream of the inlet pipe 202 and is used to rectify and distribute the high-temperature gas entering the housing 201. The liquid cooling mechanism 220 is located downstream of the flow guide 208 and occupies the main space inside the housing 201. The gas flows over the surface of the liquid cooling mechanism 220 under the guidance of the flow guide 208. The blower 204 is located downstream of the liquid cooling mechanism 220, with its air intake facing the liquid cooling mechanism 220 and its air outlet connected to the outlet pipe 203 on the housing 201.

[0045] The power drive system of the blower 204 includes a rotating device 205 and a transmission mechanism 206. The rotating device 205, as a power source, is typically an electric motor mounted outside the housing 201. The transmission mechanism 206 is used to transmit the power of the rotating device 205 to the blower 204 inside the housing 201. In one embodiment, the transmission mechanism 206 may be connected by a belt drive.

[0046] The flow guide 208 is a composite structure disposed on the upper part of the housing 201 for pretreating gas. It includes a first flow guide plate 209a and a second flow guide plate 209b. Both the first flow guide plate 209a and the second flow guide plate 209b are horizontally arranged plate-shaped members, with the first flow guide plate 209a located above the second flow guide plate 209b, and the two maintaining a preset vertical distance between them.

[0047] The stacked arrangement creates two distinct spaces. A first space is formed between the first guide plate 209a and the second guide plate 209b. A second space is formed between the first guide plate 209a and the top inner wall of the housing 201. The air inlet duct 202 of the cooling device 200 has its outlet end directly passing through the side wall of the housing 201 and extending into the first space, used to first introduce external gas into the first space for buffering and distribution.

[0048] Both the first guide plate 209a and the second guide plate 209b have a mesh structure. They can be implemented in various ways; for example, they can be perforated plates formed by punching a large number of evenly distributed through holes in a metal plate, mesh plates made of metal wire mesh or stretched mesh, or grid plates made of multiple metal strips welded together in a crisscross pattern.

[0049] The flow deflector 208 also includes an arc-shaped flow deflector plate 209c. The arc-shaped flow deflector plate 209c is an opaque, plate-shaped component with a certain curvature, which is vertically arranged. One lower edge of the arc-shaped flow deflector plate 209c is connected to the plate surface of the second flow deflector plate 209b and located in the first space, while its other upper edge extends upward, passes through the first flow deflector plate 209a, and terminates in the second space.

[0050] The liquid cooling mechanism 220 is located downstream of the flow guide 208. It includes a bracket 221, which is fixed to the inner wall of the housing 201. The bracket 221 can be a frame structure welded together from multiple rods or plates.

[0051] A coiled tube 226 for heat exchange is installed on the support 221. The coiled tube 226 is formed by bending one or more continuous metal tubes, and its overall arrangement on the support 221 can be multi-layered and horizontally coiled to obtain the maximum heat exchange area within a limited vertical space. The material of the coiled tube 226 needs to have good thermal conductivity and corrosion resistance, such as stainless steel or copper alloy. Its specific coiling form can be a circular spiral coil or a rectangular reciprocating serpentine coil.

[0052] At the two ends of the coiled tube 226, an inlet pipe 224 and an outlet pipe 222 are respectively connected to form a complete circulation loop for the cooling medium. The inlet pipe 224 is welded to one end of the coiled tube 226 or connected by threads, while the outlet pipe 222 is connected to the other end of the coiled tube 226. Both the inlet pipe 224 and the outlet pipe 222 pass through the wall plate of the housing 201 and extend to the outside of the housing 201.

[0053] At the free end of the liquid inlet pipe 224 extending to the outside of the housing 201, there is a liquid inlet 225; at the free end of the liquid outlet pipe 222, there is a liquid outlet 223. The liquid inlet 225 and the liquid outlet 223 are the interfaces for connecting the entire liquid cooling mechanism 220 to the external circulating water source. The specific interface form can be a flange, quick-connect coupling or threaded coupling, so as to facilitate installation and disassembly.

[0054] In a preferred embodiment, the disc-shaped tube 226 may be composed of one or more U-shaped tubes. It is fixed at a predetermined height inside the housing 201 by a bracket 221.

[0055] Each U-shaped tube undergoes multiple bending processes, with at least three bends. This multiple bending structure allows a single U-shaped tube to form multiple parallel, horizontally extending straight pipe sections. Overall, each U-shaped tube exhibits a reciprocating serpentine or hairpin geometry, allowing for the arrangement of longer pipelines within a flat planar area.

[0056] During installation, the U-shaped pipe, primarily consisting of horizontal pipe sections, is installed with an overall inclination in the vertical direction. Specifically, the serpentine plane formed by the U-shaped pipe creates a predetermined, non-zero angle with the horizontal plane. This ensures that the height of one end of each parallel horizontal pipe section is either higher or lower than the other end in the width direction.

[0057] In a further embodiment, this embodiment includes four cooling units. Each cooling unit includes two structurally independent liquid cooling mechanisms 220. These two liquid cooling mechanisms 220 are arranged vertically within the housing 201 to jointly cool the flowing gas.

[0058] Inside a cooling unit, two liquid cooling mechanisms 220 arranged vertically differ in structure: one is a conventional liquid cooling mechanism 220, and the other is a buffered liquid cooling mechanism 220. The conventional liquid cooling mechanism 220 has the structure described above, with its U-shaped tube directly in contact with the gas. The buffered liquid cooling mechanism 220 adds additional structures to the conventional liquid cooling mechanism 220.

[0059] The U-shaped tube of the buffer cooling mechanism 220 has an additional interlayer 227 covering the outer wall of at least one or more sections. This interlayer 227 is a sealed cavity surrounding the U-shaped tube section, formed by welding or other methods using a thin-walled metal layer, such as stainless steel or a copper alloy. Inside this cavity, a predetermined type of phase change energy storage material is filled. The phase change energy storage material can be organic materials such as industrial paraffin wax, fatty acids, and sugar alcohols, or inorganic materials such as molten salts.

[0060] In a preferred configuration, the buffer cooling mechanism 220 is located in the upper layer of the cooling unit, i.e., upstream of the gas flow path; while the conventional liquid cooling mechanism 220 is located in the lower layer of the cooling unit, i.e., downstream of the gas flow path. The high-temperature gas from the furnace 101 first flows through the buffer cooling mechanism 220, and then flows through the conventional liquid cooling mechanism 220.

[0061] In this embodiment, the conventional liquid cooling mechanism 220 and the buffer cooling mechanism 220 in the cooling unit can provide different cooling methods. In a typical heat treatment of a specific substrate foil, the substrate foil consists of multiple layers of aluminum foil and coating, and is sintered at a temperature as high as 630°C. It is extremely sensitive to thermal shock, and uneven cooling will immediately cause irreversible warping deformation.

[0062] When this batch of substrate foil with a temperature as high as 630°C needs to be cooled quickly, the inert gas in the furnace 101 is rapidly heated under the drive of the blower 204, forming an initial heat flow with a temperature as high as 600°C that impacts the cooling device 200.

[0063] If only a conventional liquid cooling mechanism 220 is used: at the instant of the 600℃ heat flux impact, the gas directly contacts the U-shaped tube through which the coolant circulates. The extremely high heat flux density causes drastic fluctuations in the temperature of the U-shaped tube wall, resulting in highly unstable heat exchange and varying amounts of heat being carried away from the tube wall. This unstable heat dissipation capacity is reflected in the substrate foil as a continuously changing cooling intensity on its surface, easily creating an uneven temperature gradient within the foil, generating enormous thermal stress, and ultimately leading to product warping and a decrease in yield.

[0064] The cooling unit in this embodiment employs the following: at the instant of the 600°C heat flow impact, the gas first flows through the buffer cooling mechanism 220 arranged upstream of the cooling unit. For example, a high-temperature molten salt with a phase change temperature of 450°C can be used as the phase change energy storage material.

[0065] In the initial stage of cooling: the 600°C gas transfers heat to the solid phase change material layer. After absorbing heat, the material layer's temperature rapidly rises to 450°C and begins to melt. Throughout the melting process, the material layer absorbs latent heat, but its surface temperature is constantly clamped at 450°C by physical properties. Therefore, the originally unstable peak heat flow of up to 600°C is reduced and transformed into a steady heat flow with its temperature precisely stabilized at 450°C after passing through this buffer mechanism.

[0066] The system then enters a steady-state cooling phase: the pre-treated, stable airflow at a constant temperature of 450°C continues to flow downwards, reaching the conventional liquid cooling unit 220 located downstream. At this point, the conventional liquid cooling unit 220 no longer faces an extreme impact of 600°C, but rather a fully controllable and stable heat load of 450°C. It can then efficiently and effectively cool the airflow further and evenly from 450°C to 250°C before sending it back to the furnace 101.

[0067] This process ensures that the heat removal from the substrate foil surface is stable and uniform, effectively preventing destructive thermal stress from forming inside the foil. Ultimately, the cooling units work together to achieve rapid, highly uniform, and controllable cooling of the heat-sensitive substrate foil, fundamentally solving the technical challenge of product warping and deformation due to thermal shock, and significantly improving product yield and quality consistency.

[0068] This embodiment also provides a cooling method for the degreasing sintering furnace as described above, comprising the following steps: S1: Perform cooling preparation steps; S11: Stop the operation of the hot air circulation duct 110, the steps of which include stopping the heating of the heat source 400 and stopping the operation of the air source 300; S12: Inert gas is supplied into the furnace 101 through an inert gas supply system to perform the cooling step in an inert gas environment; S2: Perform the cooling step: S21: Start the blower 204 in the cooling device 200 to drive the gas in the furnace 101 into an independent cooling circulation path; S22: The gas flowing in the cooling circulation path is cooled by flowing through the liquid cooling mechanism 220; S23: The cooled low-temperature gas is sent back to the furnace 101 and continuously circulated in a closed loop until the temperature of the furnace 101 drops to the preset value.

[0069] The above embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A defatting sintering furnace, comprising: a furnace body (100) having a furnace chamber (101) inside; a heat circulation air duct (110) communicating with the furnace chamber (101) to form a heating circulation path; a wind source (300) and a heat source (400) both arranged in the heat circulation air duct (110), the wind source (300) being used to drive gas to flow through the heat source (400) to heat the furnace chamber (101); characterized in that further comprising: a cooling device (200) arranged outside the furnace body (100), the cooling device (200) having a cooling air duct (210) inside, the cooling air duct (210) communicating with the furnace chamber (101) to form an independent cooling circulation path; a blowing device (204) arranged in the cooling air duct (210) and used to drive gas in the furnace chamber (101) to flow in the cooling circulation path; a liquid cooling mechanism (220) arranged in the cooling air duct (210) and used to cool the gas flowing therethrough; an inert gas supply system including a blowing pipe (102) arranged in the furnace chamber (101) and an inert gas source for supplying inert gas to the blowing pipe (102), the inert gas supply system enabling at least the cooling process of the furnace chamber (101) to be carried out in inert gas.

2. The debinding sintering furnace according to claim 1, characterized in that: The cooling air duct (210) comprises: an external air duct (211) arranged in the cooling device (200); a connecting air duct (212) and a blowing air duct (213) arranged at the bottom of the furnace chamber (101), the external air duct (211), the connecting air duct (212) and the blowing air duct (213) being sequentially communicated; wherein the blowing air duct (213) is provided with two, the two blowing air ducts (213) being arranged along the opposite inner walls of the furnace chamber (101) respectively and provided with a plurality of first blowing ports (214) facing the inside of the furnace chamber (101).

3. The debinding sintering furnace of claim 2, wherein: The connecting air duct (212) is also provided with a second blowing port (215), the airflow path blown out of the second blowing port (215) being perpendicular to the airflow path blown out of the first blowing port (214).

4. The debinding sintering furnace of claim 1, wherein: The heat circulation air duct (110) further comprises: an extension air duct (112) arranged at the bottom region of the furnace chamber (101); at least one jetting unit arranged at the sidewall region of the furnace chamber (101); wherein each jetting unit is composed of four jetting pipes (111), and the jetting directions of the four jetting pipes (111) are different from each other.

5. The debinding sintering furnace according to any one of claims 1 to 4, characterized in that: The cooling device (200) comprises: a shell (201), the blowing device (204) and the liquid cooling mechanism (220) being arranged in the shell (201); an air inlet pipe (202) and an air outlet pipe (203) communicating the shell (201) with the furnace chamber (101) to form the cooling air duct (210), the air inlet pipe (202) and the air outlet pipe (203) being respectively provided with valves (207); a flow guide (208) arranged in the shell (201), the flow guide (208) being used to guide gas to flow uniformly over the surface of the liquid cooling mechanism (220). A rotating device (205) and a transmission mechanism (206) connecting the rotating device (205) and the air blowing device (204) to drive the air blowing device (204) to rotate.

6. The debinding sintering furnace of claim 5, wherein: The flow guide (208) comprises first and second flow guide plates (209a and 209b) arranged in a grid pattern and spaced apart in the shell (201); a first space is formed between the first and second flow guide plates (209a and 209b), and the air inlet pipe (202) communicates with the first space; a second space is formed between the first flow guide plate (209a) and the top wall of the shell (201). An arc-shaped flow guide plate (209c) extends to the first and second spaces at two ends thereof.

7. The debinding sintering furnace according to any one of claims 1 to 4, characterized in that: The liquid cooling mechanism (220) comprises: a bracket (221); a disc-shaped pipe (226) arranged on the bracket (221); an inlet pipe (224) and an outlet pipe (222); one end of the disc-shaped pipe (226) is connected to the inlet pipe (224), and the other end is connected to the outlet pipe (222); the inlet pipe (224) and the outlet pipe (222) are respectively provided with an inlet (225) and an outlet (223); an external circulating water source connected to the inlet (225) and the outlet (223).

8. The debinding sintering furnace of claim 7, wherein: The disc-shaped pipe (226) is composed of at least one U-shaped pipe; each U-shaped pipe has at least three bends to form a plurality of pipe segments extending in the horizontal direction; and the U-shaped pipe is inclined as a whole in the vertical direction, so that the plurality of pipe segments form a preset inclination angle.

9. The debinding sintering furnace of claim 8, wherein: Further comprising at least one cooling unit, each cooling unit being composed of two liquid cooling mechanisms (220) arranged in the vertical direction; in each cooling unit, the U-shaped pipe of one liquid cooling mechanism (220) is provided with a cladding layer (227) formed by sealingly covering the outer wall of at least one pipe segment, and the cladding layer (227) is filled with phase change energy storage material.

10. A method of cooling a debinding sintering furnace as claimed in any one of the claims 1-9, characterized in that, The method comprises the following steps: S1: performing a cooling preparation step; S11: stopping the operation of the thermal cycle air duct (110), which includes stopping the heating of the heat source (400) and stopping the operation of the air source (300); S12: supplying inert gas into the furnace (101) through an inert gas supply system to perform a cooling step in an inert gas environment; S2: performing a cooling step: S21: starting the air blowing device (204) in the cooling device (200) to drive the gas in the furnace (101) into an independent cooling circulation path; S22: making the gas flowing in the cooling circulation path flow through the liquid cooling mechanism (220) to be cooled; S23: sending the low-temperature gas after cooling back to the furnace (101) and continuously performing closed-loop circulation until the temperature of the furnace (101) is reduced to a preset value.

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