A net-belt type gas protection ammonia furnace suitable for iron-nickel alloy parts

Abstract

The application relates to the technical field of heat treatment equipment, in particular to a mesh belt type gas protection ammonia gas furnace suitable for iron-nickel alloy parts. The mesh belt type gas protection ammonia gas furnace comprises a feeding table, a preheating section, a heating section, a water cooling section, a curtain air cooling section and a discharging table which are sequentially arranged, a conveying mesh belt is arranged between the feeding table and the discharging table, and the conveying mesh belt sequentially passes through the preheating section, the heating section, the water cooling section and the curtain air cooling section; a flow guide module is arranged on one side of the water cooling section close to the heating section; an airtight module is arranged on one side of the preheating section close to the feeding table, a heat preservation conveying pipeline is arranged between the airtight module and the flow guide module, the flow guide module can convey high-temperature gas to the airtight module through the heat preservation conveying pipeline, so that the airtight module sprays the high-temperature gas to form an air knife seal. The application has the effect of saving production cost.

Description

Technical Field

[0001] This application relates to the technical field of heat treatment equipment, and in particular to a mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts. Background Technology

[0002] Currently, in modern industrial manufacturing, iron-nickel alloys, due to their unique physical and chemical properties such as low coefficient of expansion, good magnetic properties, and corrosion resistance, are widely used in many high-end industries such as electronics, aerospace, and precision instruments. The performance and quality of iron-nickel alloy parts directly affect the reliability and stability of related products, and heat treatment technology, as a key link in improving the performance of iron-nickel alloy parts, plays a vital role in promoting the progress of these high-end industries.

[0003] In related technologies, a common heat treatment process involves using a vacuum furnace to process iron-nickel alloy parts. However, the internal space of a vacuum furnace is small, limiting the number of parts that can be processed at one time. Furthermore, the entire heat treatment process includes steps such as vacuuming, heating, holding, and cooling, which takes a considerable amount of time, resulting in low overall production efficiency. To improve production efficiency, the industry has begun to use continuous mesh belt heat treatment furnaces. The basic workflow is as follows: the workpiece is placed on a mesh belt and passes sequentially through a preheating section, a high-temperature heating section, and a cooling section within a muffle furnace filled with a protective atmosphere, completing the entire heat treatment process.

[0004] Regarding the aforementioned technologies: During heat treatment, a large amount of the high-temperature protective atmosphere and the heated workpiece will move from the high-temperature zone (heating furnace section) to the low-temperature zone (cooling section). This heat is usually carried away and dissipated directly by the cooling section, failing to be effectively recovered and utilized, thus resulting in energy waste and significantly increasing the production cost per unit product. Summary of the Invention

[0005] To save production costs, this application provides a mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts.

[0006] This application provides a mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts, employing the following technical solution:

[0007] A mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts, comprising:

[0008] The system consists of a loading platform, a preheating section, a heating section, a water-cooling section, a curtain air-cooling section, and a discharge platform arranged in sequence. A conveyor belt is provided between the loading platform and the discharge platform, and the conveyor belt passes through the preheating section, the heating section, the water-cooling section, and the curtain air-cooling section in sequence.

[0009] A flow-guiding module is provided on the side of the water-cooling section closest to the heating section;

[0010] An airtight module is provided on the side of the preheating section near the feeding platform. An insulated conveying pipeline is provided between the airtight module and the flow guiding module. The flow guiding module can deliver gas to the airtight module through the insulated conveying pipeline, so that the airtight module can spray gas to form an air knife seal.

[0011] By adopting the above technical solution, a sequentially arranged feeding platform, preheating section, heating section, water cooling section, curtain air cooling section, and discharge platform are first set up, and connected in series by a conveyor belt. This allows the iron-nickel alloy parts to be processed in an orderly manner in different sections, ensuring the continuity of the heat treatment process. A diversion module is set on the side of the water cooling section near the heating section to collect the high-temperature gas discharged from the heating section. An airtight module is set on the side of the preheating section near the feeding platform, and the two are connected by an insulated conveying pipeline. The diversion module can transport the collected high-temperature gas to the airtight module, allowing the airtight module to spray high-temperature gas to form an air knife seal. This facilitates the use of the strong thermal kinetic energy and buoyancy effect of the high-temperature gas to form a non-contact "thermal barrier." Its sealing effect is greater than that of traditional cold air curtains or flame curtains, effectively preventing air from entering the furnace, ensuring the purity of the furnace atmosphere, improving the heat treatment quality of iron-nickel alloy parts, and helping to reduce energy consumption and save production costs.

[0012] Optionally, the airtight module includes a curtain assembly and a spray assembly. The curtain assembly is disposed within the preheating section and is used to separate an outer air chamber and an inner air chamber within the preheating section. The outer air chamber is disposed near the feeding platform, and the inner air chamber is disposed near the heating section. The spray assembly is disposed on the preheating section and is connected to the inner air chamber and the heat-insulating conveying pipeline, respectively. The spray assembly is used to spray gas to form an air knife seal.

[0013] By adopting the above technical solution, the baffle assembly separates the outer air chamber and the inner air chamber within the preheating section. The outer air chamber is located near the loading platform, and the inner air chamber is located near the heating section, thus initially preventing outside air from entering the inner air chamber. The spray assembly is connected to the inner air chamber and the insulated conveying pipeline, and can spray the high-temperature gas delivered by the diversion module through the insulated conveying pipeline to form an air knife seal, further enhancing the protection of the inner air chamber and preventing outside air from flowing back into it. This maintains a high-purity atmosphere inside the furnace, avoids oxidation of the workpiece due to contact with outside air, and improves the product qualification rate.

[0014] Optionally, the curtain assembly includes a curtain body and a counterweight. The curtain body is hinged within the preheating section. One end of the curtain body near the conveyor belt is connected to the counterweight. A material box is placed on the conveyor belt, and the material box can push the curtain body to rise.

[0015] By adopting the above technical solution, the main body of the baffle is hinged in the preheating section and a counterweight is set near one end of the conveyor belt. When the material box placed on the conveyor belt moves to the main body of the baffle, the material box can push the main body of the baffle to rise with its moving thrust, so that the material box can smoothly pass through the baffle assembly and enter the inner gas chamber of the preheating section, realizing the continuous conveying of the workpiece in the furnace. After the material box passes, the gravity of the counterweight will cause the main body of the baffle to fall back to the initial position, continuing to separate the outer gas chamber and the inner gas chamber. This helps to reduce the air in the outer gas chamber from entering the inner gas chamber, enhances the sealing effect of the airtight module, and thus better maintains the purity of the atmosphere in the furnace, providing a stable environment for the heat treatment of iron-nickel alloy parts.

[0016] Optionally, the injection assembly includes a static pressure box, a driving component, and an air knife. The static pressure box is disposed on the preheating section and connected to the heat-insulating conveying pipeline. The air knife is disposed at the top of the inner air chamber and connected to the static pressure box. The driving component is disposed inside the static pressure box and is used to convey the gas inside the static pressure box to the air knife.

[0017] By adopting the above technical solution, the high-temperature gas flowing through the insulated conveying pipeline can enter the static pressure box. The driving component transports the gas in the static pressure box to the air knife, causing the air knife to spray out high-temperature gas to form an air knife seal, thereby sealing the inner air chamber in the preheating section, reducing the backflow of outside air, and thus helping to prevent the iron-nickel alloy parts from being oxidized due to outside air entering the inner air chamber, effectively ensuring the heat treatment quality of the iron-nickel alloy parts.

[0018] Optionally, the air knife is directed toward the curtain assembly and is tilted downwards.

[0019] By adopting the above technical solution, the air knife is sprayed towards the curtain assembly and is set downward. When the air knife sprays high-temperature gas to form an air knife seal, the downward-sloping spray direction allows the high-temperature gas to act better on the curtain assembly and the surrounding area. This helps to resist and block the cold air that tries to invade from below due to density difference and airflow disturbance, further enhancing the sealing effect of the air knife.

[0020] Optionally, the diversion module includes a heat exchanger, a first diversion pipe, and a second diversion pipe. The heat exchanger is located on the side of the water-cooled section near the heating section. The heat exchanger is connected to the first diversion pipe, the second diversion pipe, and the heat-insulating conveying pipeline. The first diversion pipe is connected to the side of the water-cooled section near the heating section so that the gas discharged from the heating section enters the heat exchanger. The second diversion pipe is used to introduce fresh protective gas into the heat exchanger so that the fresh protective gas exchanges heat with the gas discharged from the heating section and then enters the heat-insulating conveying pipeline.

[0021] By adopting the above technical solution, the first inlet pipe introduces the high-temperature gas discharged from the heating section into the heat exchanger, and the second inlet pipe introduces fresh protective gas into the heat exchanger. The fresh protective gas and the high-temperature gas exchange heat in the heat exchanger, thereby preheating the fresh protective gas, improving the utilization effect of the protective gas in subsequent processes, and utilizing the waste heat of the high-temperature gas to avoid heat waste and achieve efficient energy utilization. At the same time, the preheated protective gas is transported to the airtight module through the insulated conveying pipeline, which helps the airtight module form a stable and efficient air knife seal and improves the sealing performance of the furnace body.

[0022] Optionally, the heat-insulated conveying pipeline includes a main pipe and multiple branch pipes. One end of the main pipe is connected to the heat exchanger, and the other end of the main pipe is connected to the airtight module. The multiple branch pipes are respectively connected to the main pipe and are arranged along the length of the heating section and respectively connected to the heating section.

[0023] By adopting the above technical solution, the main pipe connects the heat exchanger and the airtight module, which can transport the high-temperature gas after heat exchange to the airtight module to form an air knife seal. Multiple branch pipes are arranged along the length of the heating section and connected to the heating section, which allows the high-temperature gas to enter the heating section, thereby realizing the cascade utilization of energy. Since the gas supplied to the heating section has been preheated, it will not cause a large impact on the temperature in the heating section, which helps to maintain the temperature uniformity and atmosphere stability in the heating section and ensures that the entire heating section maintains positive pressure, further improving the uniformity and reliability of heat treatment.

[0024] Optionally, a pressure chamber is provided at the bottom of the heating section, and a perforated plate is provided on the side of the pressure chamber near the heating section. The perforated plate is located below the conveyor belt, and the branch pipe is connected to the pressure chamber.

[0025] By adopting the above technical solution, the supplemented preheating protective gas first enters the pressure chamber at the bottom, and then is blown upward evenly through the perforated plate, passing through the conveyor belt and the workpiece. This effectively forms a uniform protective atmosphere flow around the workpiece, which helps to avoid the atmosphere "dead zone" caused by workpiece stacking, ensuring that all workpiece surfaces are fully protected and improving the consistency of product performance.

[0026] Optionally, the heating section is provided with multiple heating zones along the conveying direction of the conveyor belt, and each heating zone is equipped with a temperature control instrument and a thermocouple.

[0027] By adopting the above technical solution, multiple heating zones are set along the conveyor belt direction, allowing for segmented heating of the workpiece. Each heating zone is equipped with a temperature controller and a thermocouple. The thermocouple accurately monitors and records the temperature of that heating zone. The temperature controller compares the set signal with the measured signal from the thermocouple and intelligently controls the heater power of that heating zone, enabling precise temperature control of each zone. This helps ensure that the temperature of the workpiece during heat treatment meets the process requirements, improving the quality and effectiveness of the heat treatment.

[0028] Optionally, a flow regulation system is also included, which is connected to the diversion module and the water cooling section respectively. The flow regulation system is used to regulate and monitor the flow rate of the protective gas and the flow rate of the cooling water.

[0029] By adopting the above technical solution, the flow regulation system is used to regulate and monitor the flow rate of protective gas and cooling water. On the one hand, this helps to ensure that the flow rate of protective gas entering the system is stable and within a suitable range, providing a stable protective atmosphere for the heat treatment of the workpiece. This helps to avoid problems such as workpiece oxidation caused by improper protective gas flow rate and improves the product qualification rate. On the other hand, it helps to ensure the stable cooling effect of the water cooling section, thereby helping to avoid uneven cooling or over-cooling caused by abnormal cooling water flow rate, so that the workpiece can be cooled according to the process requirements and ensure the consistency of workpiece performance.

[0030] In summary, this application includes at least one of the following beneficial technical effects:

[0031] 1. The use of mesh belt continuous heating can shorten the heat treatment time, improve production efficiency, and solve the problems of long heat treatment time, small space and low efficiency of vacuum furnace;

[0032] 2. The diversion module delivers high-temperature gas to the airtight module through an insulated conveying pipeline, which causes the airtight module to spray high-temperature gas to form an air knife seal, effectively preventing hydrogen leakage from the furnace and ensuring production safety.

[0033] 3. The heating section is equipped with multiple heating zones along the conveying direction of the conveyor belt, and each heating zone is equipped with a temperature control instrument and a thermocouple, which can accurately control the heating temperature and ensure the heat treatment quality of the iron-nickel alloy parts. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the overall structure of a mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts, as shown in Embodiment 1 of this application.

[0035] Figure 2 This is a top view of a mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts, according to Embodiment 1 of this application.

[0036] Figure 3This is a partial structural diagram of the heating section and water cooling section in Embodiment 2 of this application.

[0037] Figure 4 This is a partial structural diagram of the loading platform and preheating section in Embodiment 2 of this application.

[0038] Figure 5 It is along Figure 3 A partial structural cross-sectional view of line AA in the middle.

[0039] Figure 6 It is along Figure 4 A partial structural cross-sectional view of the BB line in the middle.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1. Feeding platform; 2. Preheating section; 21. Airtight module; 211. Curtain assembly; 2111. Curtain body; 2112. Counterweight; 212. Spray assembly; 2121. Static pressure box; 2122. Drive unit; 2123. Air knife; 22. Outer air chamber; 23. Inner air chamber; 3. Heating section; 31. Pressurization chamber; 32. Perforated plate; 4. Water cooling section; 41. Cooling water tank; 42. Flow diversion module; 421. Heat exchanger; 422. First flow diversion pipe; 423. Second flow diversion pipe; 5. Door curtain air cooling section; 6. Discharge platform; 7. Flow regulation system; 71. Ammonia decomposition gas regulation assembly; 72. Cooling water regulation assembly; 8. Conveyor belt; 9. Insulated conveying pipeline; 91. Main pipe; 92. Branch pipe. Detailed Implementation

[0042] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0043] This application discloses a mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts.

[0044] It should be noted that, in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," 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.

[0045] Example 1: Refer to Figure 1 and Figure 2A mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts includes a feeding platform 1, a preheating section 2, a heating section 3, a water-cooling section 4, a curtain air-cooling section 5, a discharge platform 6, and a flow regulation system 7. The feeding platform 1, preheating section 2, heating section 3, water-cooling section 4, curtain air-cooling section 5, and discharge platform 6 are arranged sequentially, and a conveyor mesh belt 8 is installed between the feeding platform 1 and the discharge platform 6, passing sequentially through the preheating section 2, heating section 3, water-cooling section 4, and curtain air-cooling section 5.

[0046] Specifically, the structure of the discharge platform 6 is the same as that of the loading platform 1. The loading platform 1 is a steel structure welded from shaped steel, and several sets of rollers are installed on the loading platform 1. In this embodiment, four sets of rollers are provided, and two of the four sets of rollers are provided with vulcanized rubber. The conveyor belt 8 is sandwiched between the two sets of rollers, thereby driving the conveyor belt 8 to move through friction.

[0047] A transmission mechanism is installed on the lower end face of the loading platform 1. The transmission mechanism includes a motor and a reducer. The reducer pulls the rollers through a chain, and the motor drives the rollers to rotate through the reducer, thereby driving the conveyor belt 8 to run. In this embodiment, the motor is a variable frequency motor, and the speed is adjusted by a frequency converter. The variable frequency speed is set and recorded on the touch screen.

[0048] A material box is placed on the conveyor belt 8. The material box has a hollow design and contains workpieces, so that the material box can be moved by the conveyor belt 8 so that the workpieces pass through the loading platform 1, the preheating section 2, the heating section 3, the water cooling section 4, the curtain air cooling section 5, and the unloading platform 6 in sequence.

[0049] The preheating section 2 is a tunnel type, with one end connected to the feeding platform 1 and the other end connected to the heating section 3 via a flange. In this embodiment, a continuously lit lamp is installed at the inlet of the preheating section 2. This lamp can use ammonia decomposition gas to ignite the hydrogen gas leaking out of the heating section 3, forming a flame curtain to prevent hydrogen gas from leaking out of the heating section 3. A flame monitoring device is also installed on the continuously lit lamp to monitor or ignite it at any time.

[0050] The inlet of preheating section 2 is equipped with a manual furnace door and an exhaust hood. Since flammable and explosive gases are introduced into the furnace, for safety reasons, the inlet of preheating section 2 should not be directly opposite a door or window to prevent outdoor airflow from entering the tunnel and causing an explosion.

[0051] Heating section 3 includes a heating frame and a muffle furnace installed within the heating frame. The heating frame is made of structural steel, and multiple layers of refractory insulation material are laid inside the heating frame. In this embodiment, the refractory insulation material can be a composite structure of lightweight insulating bricks and ceramic fiber modules to ensure good insulation performance.

[0052] The muffle is formed by bending and welding two whole plates. The upper part is bent into an arch shape, and the lower part is bent into a U shape, thus forming a heating channel. In this embodiment, the muffle is made of heat-resistant stainless steel sheet, such as 310S stainless steel.

[0053] Heaters are symmetrically arranged above and below the muffle to achieve double-sided radiant heating of the workpiece, improving heating uniformity. To support the heaters and provide electrical insulation, corundum ceramic tubes are installed at the heater mounting locations. The heaters are preferably made of iron-chromium-aluminum alloy and are spirally wound around the corundum ceramic tubes. The heater leads are led out through the side of heating section 3, and the lead ends employ threaded locking and ceramic sealing structures to ensure airtightness and electrical safety.

[0054] Heating section 3 has multiple heating zones along the conveyor belt 8, each equipped with a temperature controller and thermocouples. In this embodiment, there are 12 heating zones, and the thermocouples are dual K-type thermocouples. One thermocouple is connected to the temperature controller for closed-loop temperature control, and the other is connected to a paperless recorder for process data recording and traceability. Additionally, several more monitoring thermocouples can be added to improve system reliability.

[0055] The conveyor belt 8 is woven from heat-resistant steel wire made of high-temperature alloy. For example, a balanced weaving structure with a braiding diameter of 3 mm and a threading diameter of 4 mm can be used to ensure its load-bearing capacity and stable operation at high temperatures.

[0056] The two ends of the water-cooled section 4 are connected to the heating section 3 and the curtain air-cooled section 5 via connecting flanges, respectively. In this embodiment, the water-cooled section 4 includes a water-cooled frame and three sets of water-cooled jackets installed on the water-cooled frame, which together form a water-cooled tunnel. Valves and connecting pipes are designed at the neck of the water-cooled jackets, allowing connection to an oxygen analyzer or dew point meter to monitor the protective atmosphere inside the furnace.

[0057] The water-cooling section 4 has a cooling water inlet at the bottom and a cooling water outlet at the top, and both the cooling water inlet and outlet are connected to the cooling water tank 41 to facilitate the circulation and venting of cooling water. When a high-temperature workpiece enters the water-cooling section 4 along the conveyor belt 8, the circulating cooling water can efficiently remove the heat from the workpiece, achieving rapid cooling.

[0058] The water-cooling section 4 is equipped with a protective gas inlet device. The protective gas enters the water-cooling section 4 through a sealed outlet to maintain a slight positive pressure inside the water-cooling section 4, preventing secondary oxidation of the workpiece during the transition from high temperature to low temperature, thereby ensuring the bright surface quality of the final product.

[0059] One end of the curtain air-cooling section 5 is connected to the water-cooling section 4 via a flange, and the other end is connected to the discharge platform 6. A protective gas sealing device is installed inside the curtain air-cooling section 5 to prevent air from entering the furnace to oxidize the workpiece, delaying the leakage of protective gas and thus conserving protective gas. In this embodiment, a constantly lit lamp is also installed at the curtain air-cooling section 5.

[0060] The flow regulation system 7 includes an ammonia decomposition gas regulating component 71 and a cooling water regulating component 72. The ammonia decomposition gas regulating component 71 includes an ammonia decomposition gas supply pipeline and a manual glass rotor flowmeter with a lower flow limit alarm function installed on the ammonia decomposition gas supply pipeline. After passing through the manual glass rotor flowmeter, the ammonia decomposition gas supply pipeline splits into two branches and enters the heating section 3. The ammonia decomposition gas supply pipeline is also connected to an external protective gas source to facilitate the introduction of ammonia decomposition gas into the heating section 3 and to facilitate the regulation of the ammonia decomposition gas flow rate. In this embodiment, the total flow rate of the ammonia decomposition gas is output by a 4-20mA signal provided by the protective gas source and connected to a PLC for real-time detection and alarm parameter setting.

[0061] In another preferred embodiment, a nitrogen supply pipeline can also be provided, which is divided into three paths and enters the heating section 3 after passing through a manual glass rotor flow meter.

[0062] The cooling water regulating assembly 72 includes cooling water pipes, a cooling water shortage audible and visual alarm, and a thermal resistance temperature sensor. The cooling water pipes are connected to the cooling water inlet and the cooling water tank 41, and are also equipped with a manual glass rotor flow meter with a lower limit alarm function. After passing through the manual glass rotor flow meter, the cooling water pipes are divided into six paths into the water-cooled section 4.

[0063] A cooling water shortage audible and visual alarm is installed at the cooling water inlet to ensure uninterrupted cooling. A resistance temperature sensor is installed on the pipe corresponding to the cooling water outlet. The temperature signal it collects is converted into a 4-20mA signal and input to the PLC. Operators can set over-temperature alarm values ​​and view real-time temperature curves on the touch screen.

[0064] It should be noted that in this embodiment, a PLC controller is used to control the coordinated operation of various parts, and a human-machine interface touch screen is used to display the working status in real time, facilitating operators to modify and control various parameters. Furthermore, in this embodiment, the protective atmosphere used is ammonia decomposition gas, which is a mixture of hydrogen and nitrogen produced after the decomposition of liquid ammonia.

[0065] The implementation principle of a mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts according to an embodiment of this application is as follows: The operator first sets the process parameters such as heating temperature, holding time, and conveyor belt 8 running speed via a touch screen. Then, the material box containing the iron-nickel alloy parts is placed on the corresponding conveyor belt 8 on the loading platform 1. After the equipment is started, the conveyor belt 8 runs continuously at the set speed, driving the workpieces sequentially into the preheating section 2, heating section 3, water cooling section 4, and curtain air cooling section 5.

[0066] In preheating section 2, the workpiece is slowly preheated while a fire curtain at the furnace opening prevents air from entering. Upon entering heating section 3, the workpiece undergoes a heating and isothermal heat treatment process under precise control across multiple temperature zones, following a set temperature curve. The entire process is conducted in an environment with ammonia decomposition protective gas to prevent oxidation. After heat treatment, the workpiece enters water cooling section 4, where it is rapidly cooled by a water-cooling jacket.

[0067] Subsequently, the workpiece passes through the air-cooled section 5, which is protected by an air curtain, for further cooling and to prevent oxidation upon exiting the furnace. Finally, the heat-treated workpiece arrives at the unloading platform 6. The entire process is continuous, automatic, and efficient.

[0068] Example 2: Refer to Figure 3 and Figure 4 The difference between this embodiment and embodiment 1 is that a diversion module 42 is provided on the side of the water cooling section 4 near the heating section 3, and an airtight module 21 is provided on the side of the preheating section 2 near the feeding platform 1. A heat-insulating conveying pipeline 9 is provided between the airtight module 21 and the diversion module 42.

[0069] Reference Figure 3 The diversion module 42 includes a heat exchanger 421, a first diversion pipe 422, and a second diversion pipe 423. The heat exchanger 421 is located on the side of the water-cooled section 4 closest to the heating section 3. One end of the first diversion pipe 422 is connected to the heat exchanger 421, and the other end is connected to the side of the water-cooled section 4 closest to the heating section 3, allowing the high-temperature protective gas discharged from the heating section 3 to enter the heat exchanger 421. Furthermore, an exhaust pipe is connected to the outlet of the heat exchanger 421, which can directly transport the high-temperature protective gas after heat exchange to subsequent processing stages for discharge.

[0070] In another preferred embodiment, two first drain pipes 422 may also be provided. The two first drain pipes 422 are respectively connected to the heat exchanger 421 and the water cooling section 4. One of the two first drain pipes 422 is connected to the side of the water cooling section 4 near the heating section 3, so that the high-temperature protective gas discharged from the heating section 3 can enter the heat exchanger 421, and after passing through the heat exchanger 421, it flows back to the water cooling section 4 through the other first drain pipe 422, and then the high-temperature protective gas after heat exchange continues to protect the workpiece.

[0071] Heat exchanger 421 is connected to an external protective gas source via a second inlet pipe 423. The high-temperature protective gas transfers its large amount of heat energy to the fresh protective gas within the heat exchanger 421, preheating the fresh protective gas to a high temperature before it enters the furnace.

[0072] The preheated high-temperature fresh protective gas is transported through the insulated conveying pipeline 9. The insulated conveying pipeline 9 has a double-layered structure, with insulation material filling the middle to prevent heat loss. In this embodiment, the insulated conveying pipeline 9 includes a main pipe 91 and multiple branch pipes 92.

[0073] Reference Figure 3 and Figure 4 One end of the main pipe 91 is connected to the heat exchanger 421, and the other end of the main pipe 91 is connected to the airtight module 21. Multiple branch pipes 92 are connected to the main pipe 91 respectively. The multiple branch pipes 92 are arranged along the length of the heating section 3, and the number of branch pipes 92 is equal to the number of heating zones and corresponds one to one.

[0074] Reference Figure 3 and Figure 5 A pressurization chamber 31 is provided at the bottom of the heating section 3. A perforated plate 32 is provided on the side of the pressurization chamber 31 near the conveyor belt 8. The perforated plate 32 is located below the conveyor belt 8, and the branch pipe 92 is connected to the pressurization chamber 31. When the heat preservation conveying pipeline 9 conveys high-temperature protective gas, the high-temperature protective gas can flow into the pressurization chamber 31 through the branch pipe 92, and then enter the heating zone through the pressurization chamber 31. This makes the gas distribution more uniform, and can effectively form a uniform protective atmosphere flow around the workpiece, so as to avoid the atmosphere "dead zone" caused by the stacking of workpieces, ensure that all workpiece surfaces are fully protected, and improve the consistency of product performance.

[0075] Reference Figure 4 and Figure 6 The airtight module 21 includes a curtain assembly 211 and a spray assembly 212. The curtain assembly 211 is disposed in the preheating section 2 and is used to separate the outer air chamber 22 and the inner air chamber 23 in the preheating section 2. The outer air chamber 22 is disposed near the loading platform 1.

[0076] The curtain assembly 211 includes a curtain body 2111 and a counterweight 2112. The curtain body 2111 is hinged in the preheating section 2, and the end of the curtain body 2111 near the conveyor belt 8 is connected to the counterweight 2112. In this embodiment, the counterweight 2112 can be wrapped with a flexible protective sleeve to avoid rigid collisions.

[0077] As the material box on the conveyor belt 8 moves forward, the front wall of the material box pushes the counterweight 2112, causing the curtain body 2111 to flip and lift upward, allowing the workpiece inside the material box to pass through without contact. After the material box passes, the curtain body 2111 will automatically fall back under the action of the counterweight 2112. The whole process requires no manual intervention and avoids scratching the surface of the workpiece.

[0078] The injection assembly 212 includes a static pressure chamber 2121, a drive unit 2122, and an air knife 2123. The static pressure chamber 2121 is located on the preheating section 2 and communicates with the main pipe 91. The air knife 2123 is located on the top of the inner air chamber 23 and communicates with the static pressure chamber 2121. The drive unit 2122 is located inside the static pressure chamber 2121. In this embodiment, the drive unit 2122 is a high-temperature fan used to transport the gas in the static pressure chamber 2121 to the air knife 2123.

[0079] The air knife 2123 is directed towards the curtain assembly 211 and is set downwards. The high-temperature gas delivered by the main pipe 91 is pressurized in the static pressure box 2121 and then sprayed at high speed downwards towards the curtain assembly 211 through the air knife 2123, forming a strong high-temperature and high-speed "air knife". This forms a non-contact thermal barrier, effectively preventing air from entering and preheating and pre-purifying the atmosphere for the workpieces about to enter the furnace.

[0080] The implementation principle of Example 2 is as follows: After the heat treatment is completed, the high-temperature protective gas discharged from the heating section 3 enters the heat exchanger 421, and the heat it carries is transferred to the ambient temperature fresh protective gas introduced from the outside, so as to realize waste heat recovery and preheat the fresh protective gas into high-temperature gas.

[0081] A portion of the preheated high-temperature fresh protective gas is transported to the static pressure chamber 2121 via the main pipe 91, and then to the air knife 2123 via the drive component 2122, thus forming a high-temperature, high-speed air knife within the inner gas chamber 23. The other portion of the preheated high-temperature fresh protective gas is transported to the pressurization chamber 31 via the branch pipe 92, and then evenly replenished into the heating section 3 via the perforated plate 32 to maintain positive pressure inside the furnace and ensure the uniformity and stability of the atmosphere.

[0082] Meanwhile, the conveyor belt 8 drives the material box through the preheating section 2, heating section 3, water cooling section 4 and door curtain air cooling section 5 in sequence to complete the entire bright heat treatment process.

[0083] In another preferred embodiment, the diversion module 42 may be omitted, and the high-temperature protective gas discharged from the heating section 3 may be directly transported to the static pressure box 2121 through the heat-insulated conveying pipeline 9.

[0084] It should be noted that the temperature of the "high-temperature gas" referred to in this application is not a fixed value; it is related to factors such as the process temperature of the heating section and the heat exchange efficiency. In a specific process scenario of this application, for example, when the operating temperature of the heating section 3 is set to 900°C, the temperature of the protective gas discharged from the heating section 3 is very high. After the fresh protective gas is heated by the heat exchanger 421, the resulting "high-temperature gas" delivered to the airtight module 21 can reach a temperature in the range of, for example, 350°C to 550°C. Within this temperature range, the gas density is significantly lower than that of the outside air, and the resulting air knife seal can effectively utilize the thermal buoyancy effect to block the intrusion of cold air, and provide good preheating and atmosphere pre-purification for the workpieces about to enter the furnace.

[0085] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts, characterized in that, include: The loading platform (1), preheating section (2), heating section (3), water cooling section (4), door curtain air cooling section (5) and discharge platform (6) are arranged in sequence. A conveyor belt (8) is arranged between the loading platform (1) and the discharge platform (6). The conveyor belt (8) passes through the preheating section (2), the heating section (3), the water cooling section (4) and the door curtain air cooling section (5) in sequence. A flow-guiding module (42) is provided on the side of the water-cooling section (4) close to the heating section (3). An airtight module (21) is provided on the side of the preheating section (2) near the feeding platform (1), and an insulated conveying pipeline (9) is provided between the airtight module (21) and the diversion module (42). The diversion module (42) includes a heat exchanger (421), a first diversion pipe (422), and a second diversion pipe (423). The heat exchanger (421) is located on the side of the water-cooled section (4) near the heating section (3). The heat exchanger (421) is connected to the first diversion pipe (422), the second diversion pipe (423), and the heat-insulating conveying pipeline (9). The first diversion pipe (422) is connected to the side of the water-cooled section (4) near the heating section (3) so that the high-temperature gas discharged from the heating section (3) enters the heat exchanger (421). The second diversion pipe (423) is used to introduce fresh protective gas into the heat exchanger (421) so that the fresh protective gas exchanges heat with the high-temperature gas and then enters the heat-insulating conveying pipeline (9). The airtight module (21) includes a curtain assembly (211) and a spray assembly (212). The curtain assembly (211) is disposed in the preheating section (2) and is used to separate an outer air chamber (22) and an inner air chamber (23) in the preheating section (2). The outer air chamber (22) is disposed near the loading platform (1), and the inner air chamber (23) is disposed near the heating section (3). The injection assembly (212) includes a static pressure box (2121), a drive unit (2122), and an air knife (2123). The static pressure box (2121) is located on the preheating section (2) and is connected to the heat-insulating conveying pipeline (9). The air knife (2123) is located at the top of the inner air chamber (23) and is connected to the static pressure box (2121). The drive unit (2122) is located inside the static pressure box (2121). The drive unit (2122) is used to transport the gas in the static pressure box (2121) to the air knife (2123) so that the air knife (2123) sprays out high-temperature gas to form an air knife seal.

2. The mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts according to claim 1, characterized in that: The curtain assembly (211) includes a curtain body (2111) and a counterweight (2112). The curtain body (2111) is hinged in the preheating section (2). One end of the curtain body (2111) near the conveyor belt (8) is connected to the counterweight (2112). A material box is placed on the conveyor belt (8), and the material box can push the curtain body (2111) to lift.

3. The mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts according to claim 1, characterized in that: The air knife (2123) is directed toward the curtain assembly (211) and is tilted downwards.

4. The mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts according to claim 1, characterized in that: The insulated conveying pipeline (9) includes a main pipe (91) and multiple branch pipes (92). One end of the main pipe (91) is connected to the heat exchanger (421), and the other end of the main pipe (91) is connected to the airtight module (21). The multiple branch pipes (92) are respectively connected to the main pipe (91). The multiple branch pipes (92) are arranged along the length of the heating section (3) and are respectively connected to the heating section (3).

5. The mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts according to claim 4, characterized in that: The bottom of the heating section (3) is provided with a pressure chamber (31). A perforated plate (32) is provided on the side of the pressure chamber (31) near the heating section (3). The perforated plate (32) is located below the conveyor belt (8). The branch pipe (92) is connected to the pressure chamber (31).

6. The mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts according to claim 1, characterized in that: The heating section (3) is provided with multiple heating zones along the conveying direction of the conveyor belt (8), and each heating zone is equipped with a temperature control instrument and a thermocouple.

7. The mesh belt gas-protected ammonia furnace suitable for iron-nickel alloy parts according to claim 1, characterized in that: It also includes a flow regulation system (7), which is connected to the diversion module (42) and the water cooling section (4) respectively. The flow regulation system (7) is used to regulate and monitor the flow rate of the protective gas and the flow rate of the cooling water.

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