Energy recycling equipment for metal brazing

Abstract

The invention relates to the technical field of metal brazing, and provides energy recycling equipment for metal brazing, which comprises a brazing furnace, a mesh belt transmission system, a heating system, an atmosphere control system and a cooling system. Through deep integration of energy recycling and precise process control, the industrial pain points that traditional brazing equipment is high in energy consumption, serious in waste heat waste, insufficient in cooling precision, poor in atmosphere stability and the like are successfully solved, and breakthrough is achieved in the aspects of improving the product quality and reducing the production cost.

Description

Technical Field

[0001] This invention relates to the field of metal brazing technology, and more specifically to an energy recycling device for metal brazing. Background Technology

[0002] Metal brazing is a precision welding process that joins metal parts by melting and filling a filler metal, utilizing the wetting, capillary flow, and interdiffusion of the liquid filler metal in the gaps between the base materials. It is widely used in high-precision manufacturing fields such as aerospace, new energy vehicles, and electronic components. Currently, the industry commonly uses mesh belt continuous brazing furnaces for automated production. These machines typically consist of a preheating section, a brazing heating section, a cooling section, a mesh belt conveyor system, and an atmosphere control system.

[0003] However, existing traditional brazing equipment still has several technical shortcomings that urgently need to be addressed in practical applications, mainly in the following aspects: First, energy efficiency is low, and operating energy consumption is enormous. The cooling section of the brazing furnace releases a large amount of high-temperature waste heat during operation. Traditional equipment typically uses only water or air cooling to directly discharge this heat into the external environment, resulting in significant energy waste. Simultaneously, to prevent workpiece oxidation, the atmosphere control system needs to continuously introduce room-temperature protective gases (such as nitrogen or argon) into the high-temperature furnace chamber. The injection of low-temperature gases significantly lowers the furnace temperature, requiring the heating system to consume additional energy to compensate for this heat loss, further exacerbating the overall energy consumption of the equipment.

[0004] Secondly, controlling the cooling quality of the workpiece is difficult and prone to defects. The cooling process is crucial to the final quality of the brazed joint. Traditional equipment has a relatively simple cooling section structure and insufficient precision in controlling the cooling rate. This can easily lead to defects such as thermal stress concentration, deformation, microcracks, or even brazing seam cracking in the workpiece (especially thin-walled and complex structural parts) due to excessively rapid or uneven cooling, which seriously affects the product's pass rate and reliability.

[0005] Furthermore, the atmosphere and thermal stability within the furnace are insufficient. Directly introducing ambient temperature protective gas into a high-temperature furnace not only causes furnace temperature fluctuations and disrupts the thermal equilibrium, but also leads to uneven atmosphere distribution due to the low temperature and high density of the gas, resulting in reduced protective effectiveness in localized areas and increasing the risk of workpiece oxidation. To ensure atmosphere purity, it is often necessary to increase the protective gas flow rate, which creates a vicious cycle in terms of energy consumption and cost.

[0006] Therefore, this solution proposes an energy recycling device for metal brazing to solve the above problems. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention aims to provide an energy recycling device for metal brazing.

[0008] To achieve the aforementioned objective, the technical solution of the present invention is as follows: an energy recycling device for metal brazing, comprising a brazing furnace, a mesh belt conveyor system, a heating system, an atmosphere control system, and a cooling system; The furnace body is provided with a preheating section, a brazing heating section and a cooling section in sequence along the workpiece conveying direction. The cooling section includes at least two continuous sub-cooling sections. The mesh belt conveyor system includes a conveyor belt that runs through the preheating section, the brazing heating section, and the cooling section, and is used to carry and transport workpieces; The heating system includes heating elements and a temperature control module located in the brazing heating section. The temperature control module is used to control the temperature of the brazing heating section in zones. The atmosphere control system includes a protective gas supply device and a heat exchange pipeline. The heat exchange pipeline is located in the cooling section, and the inlet end of the heat exchange pipeline is connected to the protective gas supply device. The heat exchange pipes in the cooling section lead to the interior of the plate heat exchanger, and are used to preheat the protective gas output by the protective gas supply device using the waste heat of the cooling section. The preheated protective gas is then introduced into the interior of the front terminal cooling section of the previous one through the outlet of the heat exchange pipes, and finally into the interior of the brazing furnace.

[0009] Preferably, the cooling section includes a first cooling section, a second cooling section, and a third cooling section arranged sequentially. If a plate heat exchanger is installed in the first cooling section, the outlet of the heat exchange pipe in the second cooling section is connected to the preheating section, and the outlet of the heat exchange pipe in the third cooling section is connected to the first cooling section. If the cooling section does not have a plate heat exchanger, the outlet of the heat exchange pipe in the cooling section is connected to the preheating section, and the outlet of the heat exchange pipe in the cooling section is connected to the cooling section.

[0010] Preferably, the cooling section is equipped with an independent deionized water supply device and circulation pipeline, and the circulation pipeline forms a closed loop with the water cooling jacket of the cooling section; the circulation pipeline is equipped with a pipeline pump and a temperature sensor, both of which are electrically connected to the control system to automatically adjust the cooling water flow rate according to the temperature of the cooling section.

[0011] The beneficial effects of this invention are reflected in: Significantly improves energy efficiency and reduces energy costs: By innovatively arranging heat exchange pipes within the cooling section and using plate heat exchangers, a large amount of waste heat released during the cooling process is systematically recovered for efficient preheating of the protective gas. The preheated protective gas is then reintroduced into the furnace, not only avoiding temperature fluctuations and additional energy compensation caused by ambient temperature gas entering a high-temperature furnace, but also achieving cascaded energy recycling. Actual operating data shows that this structure can recover over 80% of the waste heat from the cooling section, significantly reducing the power demand of the heating system. Overall energy consumption is reduced by approximately 20% to 30% compared to traditional equipment, resulting in significant long-term economic benefits.

[0012] Improving brazing process quality and product consistency: The equipment employs a zoned temperature control heating system (e.g., 3-5 independent temperature zones) combined with high-precision temperature sensors (temperature control accuracy ±1℃) and PLC automatic regulation to ensure that the temperature uniformity error within the brazing heating section is ≤±5℃, effectively avoiding defects such as incomplete melting of the brazing filler metal, poor soldering, and oxidation caused by localized overheating or insufficient heating. Simultaneously, the cooling system utilizes a multi-stage gradient cooling design (e.g., cooling stages one, two, and three) and independent closed-loop temperature control (accuracy ±3℃) for cooling stage one, enabling slow and uniform cooling of the workpiece. This significantly reduces quality problems such as deformation and micro-cracks caused by thermal stress concentration, making it particularly suitable for heat-sensitive or structurally complex precision workpieces.

[0013] Enhanced atmosphere control stability and reduced protective gas consumption: Traditional equipment directly introduces ambient temperature protective gas into the high-temperature furnace, causing a sudden drop in furnace temperature and atmosphere disturbance. This equipment preheats the protective gas using waste heat, significantly raising its temperature (up to several hundred degrees Celsius) before it enters the furnace. This reduces the energy compensation required to maintain stable furnace temperature and improves the uniformity and stability of the atmosphere, effectively inhibiting workpiece oxidation. Furthermore, the preheated protective gas has higher activity, providing better protection at the same flow rate, thus reducing total protective gas consumption by approximately 15% to 20%.

[0014] The system boasts high integration and reliable automated operation: It integrates transmission, heating, atmosphere control, cooling, and waste heat recovery systems, and achieves full-process automated control and real-time monitoring (including key process parameters such as temperature, flow rate, and speed) through a central PLC system. Operators only need to set the process formula, and the equipment can automatically complete the entire process from feeding, preheating, brazing, gradient cooling to unloading, significantly reducing reliance on operator skills, minimizing the risk of human error, and ensuring the repeatability and reliability of the production process, making it highly suitable for continuous large-scale production.

[0015] The equipment features a flexible structural design to adapt to various process requirements: it offers modular cooling section structures and heat exchange path configurations (such as whether to install plate heat exchangers and the variable connection method for multi-section cooling). Users can flexibly select configurations based on specific workpiece materials (such as copper-based and silver-based brazing fillers), brazing temperatures (800~1200℃), and cooling rate requirements, enhancing the equipment's process adaptability and application range. Furthermore, the selection and design of key components such as the high-temperature resistant mesh belt, stainless steel water jacket, and deionized water circulation system ensure the equipment's long-term durability and low maintenance requirements in high-temperature and corrosive environments.

[0016] This invention, through the deep integration of energy recycling and precision process control, not only successfully solves the industry pain points of traditional brazing equipment, such as high energy consumption, serious waste of waste heat, insufficient cooling precision, and poor atmosphere stability, but also achieves breakthroughs in improving product quality and reducing production costs. Attached Figure Description

[0017] In the attached diagram: Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the half-section structure of the present invention; Figure 3 This is a schematic diagram of the internal structure of the cooling section of the present invention (half-section). Figure 4 This is a schematic diagram of the cross-section of the cooling section of the present invention; Figure 5 This is a schematic diagram of the overall system layout of the device of the present invention; Figure 6 This is a waste heat recovery path diagram for the atmosphere control system of the present invention; Figure 7 This is a diagram of the zoned temperature control structure of the heating system of the present invention; Explanation of reference numerals in the attached figures: 1. Brazing furnace; 2. Conveyor belt; 3. Cooling muffle; 4. Plate heat exchanger; 5. Water jacket; 6. Heat exchange pipeline. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the invention, and not all of them. Unless otherwise specified, the embodiments and features described in this application can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0019] It should be noted that if the embodiments of the invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0020] Furthermore, "multiple" refers to two or more. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the invention.

[0021] Please refer to the instruction manual appendix. Figures 1-7 This invention provides an energy recycling device for metal brazing. Overall Structure Overview of the Equipment This embodiment discloses an energy recycling device for metal brazing, which aims to solve problems such as waste of residual heat in the cooling section, high energy consumption of protective gas preheating, and insufficient workpiece cooling accuracy in traditional brazing equipment. Its core technology achieves energy recycling through heat exchange with "residual heat protective gas," while combining zoned temperature control and gradient cooling to ensure brazing quality. The device consists of five core modules: brazing furnace 1, mesh belt conveyor system, heating system, atmosphere control system, and cooling system. These modules work together to achieve fully automated processing of the workpiece from preheating and brazing heating to gradient cooling.

[0022] Brazing furnace 1 is a horizontal sealed furnace body. The furnace wall is made of high-temperature resistant insulation material (such as aluminum silicate fiber cotton) to reduce heat loss inside the furnace. Along the workpiece transport direction, the furnace body is divided into three functional areas: a preheating section, a brazing heating section, and a cooling section. The cooling section contains at least two continuous sub-cooling sections, forming a gradient cooling channel.

[0023] Detailed structure and functions of each system Belt transmission system The mesh belt conveyor system, serving as the core for carrying and transporting workpieces, includes a conveyor mesh belt 2 that runs through the preheating section, brazing heating section, and cooling section, with its two ends extending to the loading and unloading areas outside the furnace body, respectively. The conveyor mesh belt 2 is made of high-temperature resistant metal material (such as 310S stainless steel woven mesh), featuring oxidation resistance, high strength, and low deformation rate. It can be adapted to an adjustable conveying speed of 0-5 m / min to meet the brazing cycle requirements of different workpieces.

[0024] During the transmission process, the workpiece is placed on the surface of the conveyor belt 2 in the feeding area and passes through the functional sections of the furnace body at a uniform speed with the conveyor belt. The entire process is non-contact transmission, avoiding scratches or contamination on the surface of the workpiece.

[0025] Heating system The heating system is used to provide a precise and stable heat source for the brazing process. It consists of a heating element and a temperature control module, both of which are integrated into the brazing heating section.

[0026] Heating elements: U-shaped resistance heating tubes or infrared heating plates are used, and they are evenly arranged along the width and height of the brazing heating section (e.g., a set of heating elements is set every 10cm). The total power is configured to 50-200kW according to the furnace specifications, which can achieve a brazing temperature coverage of 800-1200℃ and is suitable for the welding requirements of different brazing materials such as copper-based and silver-based materials.

[0027] Temperature control module: Utilizing a PLC controller linked to K-type thermocouples, the brazing heating section is divided into 35 temperature-controlled zones along the transmission direction. Each zone is equipped with an independent thermocouple and power regulator. Thermocouples collect zone temperatures in real time (accuracy ±1℃). The temperature control module automatically adjusts the power of the corresponding zone's heating elements according to preset parameters, ensuring temperature uniformity within the brazing heating section is ≤±5℃, thus avoiding brazing defects caused by localized temperature differences.

[0028] Atmosphere control system The core function of the atmosphere control system is to introduce protective gas into the furnace to isolate it from air (to prevent workpiece oxidation). At the same time, it uses a waste heat recovery structure to preheat the protective gas and reduce energy consumption. The structure includes a protective gas supply device, a heat exchange pipeline 6, and a plate heat exchanger 4.

[0029] Core component configuration Protective gas supply device: includes a high-pressure gas cylinder (stores inert protective gases such as nitrogen and argon), a pressure reducing valve, and a flow controller, which can adjust the protective gas flow rate according to the workpiece material (range: 1050m³). 3 / h).

[0030] Heat exchange pipe 6: Arranged in a spiral or serpentine shape inside the plate heat exchanger 4. The inlet end of the heat exchange pipe 6 is connected to the protective gas supply device through the main pipeline, while the outlet end is selectively connected to the preheating section, the preceding sub-cooling section, or the inside of the brazing furnace, depending on the segmented structure of the cooling section.

[0031] Plate heat exchanger 4: It adopts a stainless steel plate heat exchange structure with multiple sets of heat exchange plates inside, and the middle section of the heat exchange pipeline 6 runs through its interior. The function of plate heat exchanger 4 is to enhance heat exchange efficiency—when the residual heat in the cooling section is relatively dispersed, the heat is concentrated and transferred to the protective gas in the pipeline through the heat exchange plates, thereby achieving deep preheating of the protective gas.

[0032] Waste heat recovery process After being supplied by the protective gas supply unit, it first enters the heat exchange pipe 6 in the cooling section, absorbing the residual heat in the cooling section through the pipe wall. It then flows through the plate heat exchanger 4 for further heating, thus increasing the temperature of the preheated protective gas. The preheated protective gas is then sequentially introduced into the preceding terminal cooling section (e.g., the protective gas for cooling section two is introduced into cooling section one, and the protective gas for cooling section three is introduced into cooling section two), and finally evenly distributed into the brazing heating section and preheating section through the furnace's gas distributor. In this process, the preheated protective gas not only avoids the temperature fluctuations caused by introducing room-temperature protective gas into a high-temperature furnace, but also recovers more than 80% of the residual heat from the cooling section, reducing the energy consumption of the heating system.

[0033] Cooling system The cooling system is designed with "gradient cooling + precise temperature control" as its core, including multiple cooling sections, water jacket 5 and cooling medium circulation unit, which can prevent the workpiece from deforming or cracking due to sudden cooling.

[0034] Segmented structure of cooling section In this embodiment, the cooling section is preferably configured as a first cooling section, a second cooling section, and a third cooling section, with the three sections arranged sequentially along the transmission direction and the temperature gradient decreasing from high to low.

[0035] Water jacket 5 and cooling medium circulation Each sub-cooling section has a stainless steel water jacket 5 welded to its inner wall. The water jacket has a U-shaped cross-section and surrounds the furnace wall. The cooling medium is deionized water (to avoid scale clogging the pipes). One cooling section is equipped with an independent deionized water supply device and circulation pipeline, while the other sub-cooling sections share a single circulation system.

[0036] A pipeline pump and a platinum resistance temperature sensor (measuring range 0-500℃, accuracy ±0.5℃) are connected in series on the circulation pipeline of the cooling section. Both are electrically connected to the equipment's main control system (PLC). The temperature sensor collects the workpiece temperature in the cooling section in real time. When the temperature is higher than the preset value, the control system sends a signal to increase the speed of the pipeline pump and increase the cooling water flow rate; when the temperature is lower than the preset value, the pump speed is reduced and the flow rate is decreased, realizing automatic adjustment of the cooling temperature with a temperature control accuracy of ±3℃.

[0037] The compatibility between heat exchange pipes and cooling sections Depending on whether a plate heat exchanger 4 is installed in the cooling section, the connection method of the outlet end of the heat exchange pipe 6 is divided into two types: The first cooling section is equipped with a plate heat exchanger 4. At this time, the outlet of the heat exchange pipe 6 in the second cooling section is connected to the preheating section through a branch pipe, and the outlet of the heat exchange pipe 6 in the third cooling section is connected to the first cooling section. In this structure, the waste heat of the third cooling section is preferentially used to preheat the protective gas of the first cooling section, and the waste heat of the second cooling section directly preheats the protective gas of the preheating section, forming a stepped waste heat recovery of "rear section, front section, and preheating section". In the first cooling stage, no plate heat exchanger 4 is installed. In this case, the outlet of the heat exchange pipe 6 in the first cooling stage is directly connected to the preheating stage, and the outlet of the heat exchange pipe 6 in the second cooling stage is connected to the first cooling stage. This structure is suitable for scenarios with low waste heat demand. Waste heat recovery is achieved through the path of "second cooling stage → first cooling stage → preheating stage", simplifying the equipment structure.

[0038] Equipment working process Start-up and parameter setting: Turn on the main power supply of the equipment, and set the temperature of the preheating section, the temperature of each zone of the brazing heating section, the target temperature of each sub-section of the cooling section, the protective gas flow rate, and the conveyor belt speed through the control system.

[0039] Preheating and atmosphere preparation: The heating system is started to heat up the preheating section and the brazing heating section; at the same time, the protective gas supply device is turned on, and the protective gas absorbs the residual heat of the cooling section and is preheated through the heat exchange pipeline 6 before being introduced into the furnace to replace the air.

[0040] Workpiece transfer and brazing: The metal workpiece to be brazed (such as aluminum radiator, stainless steel pipe) is placed on the conveyor belt 2, and the workpiece enters the preheating section and brazing heating section in sequence with the conveyor belt.

[0041] Gradient cooling and waste heat recovery: After brazing, the workpiece enters the third cooling section, the second cooling section, and finally the first cooling section. During the cooling process, the cooling water in the water jacket 5 continuously removes heat, while the protective gas in the heat exchange pipe 6 simultaneously absorbs the waste heat from each cooling section. After enhanced heat exchange by the plate heat exchanger 4, it continuously supplies preheating protective gas to the preheating section and the brazing heating section.

[0042] Material feeding and circulation: After cooling, the workpiece is conveyed to the feeding area via conveyor belt 2, completing one brazing cycle. The equipment operates automatically throughout the entire process, and the control system monitors the temperature, protective gas flow rate, and cooling water flow rate of each section in real time to ensure process stability.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0044] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0045] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An energy recycling device for metal brazing, characterized in that, Includes a brazing furnace (1), a mesh belt conveyor system, a heating system, an atmosphere control system, and a cooling system; The furnace body is provided with a preheating section, a brazing heating section and a cooling section in sequence along the workpiece conveying direction, and the cooling section includes at least two continuous sub-cooling sections; The mesh belt conveyor system includes a conveyor mesh belt (2) that runs through the preheating section, the brazing heating section and the cooling section, for carrying and conveying workpieces; The heating system includes a heating element and a temperature control module disposed in the brazing heating section. The temperature control module is used to perform zoned temperature control of the brazing heating section. The atmosphere control system includes a protective gas supply device and a heat exchange pipeline (6). The heat exchange pipeline is installed in the cooling section, and the inlet end of the heat exchange pipeline is connected to the protective gas supply device. The heat exchange pipe (6) in the cooling section leads to the interior of the plate heat exchanger (4) to preheat the protective gas output by the protective gas supply device using the residual heat of the cooling section. The preheated protective gas is then introduced into the interior of the front terminal cooling section of the previous one through the outlet of the heat exchange pipe (6) and finally into the interior of the brazing furnace (1). A water jacket (5) for cooling is also installed on the inner wall of the cooling section.

2. The energy recycling equipment for metal brazing according to claim 1, characterized in that, The cooling section includes a first cooling section, a second cooling section, and a third cooling section arranged sequentially. If a plate heat exchanger (4) is provided in the first cooling section, the outlet end of the heat exchange pipe (6) in the second cooling section is connected to the preheating section, and the outlet end of the heat exchange pipe (6) in the third cooling section is connected to the first cooling section. If the cooling section is not equipped with a plate heat exchanger (4), the outlet of the heat exchange pipe (6) in the cooling section is connected to the preheating section, and the outlet of the heat exchange pipe (6) in the cooling section is connected to the cooling section.

3. The energy recycling equipment for metal brazing according to claim 2, characterized in that, The cooling section is equipped with an independent deionized water supply device and circulation pipeline. The circulation pipeline forms a closed loop with the water cooling jacket of the cooling section. The circulation pipeline is equipped with a pipeline pump and a temperature sensor. Both the pipeline pump and the temperature sensor are electrically connected to the control system and are used to automatically adjust the cooling water flow rate according to the temperature of the cooling section.

Images