A normalizing furnace based on rapid cooling technology

Abstract

The application discloses a normalizing furnace based on a rapid cooling technology and belongs to the technical field of metal heat treatment cooling systems. The normalizing furnace body is internally divided into a heating cavity for normalizing workpieces and a cooling cavity for cooling the workpieces. The heating cavity and the cooling cavity are slidably provided with a discharge door. The heating cavity and the cooling cavity are separated by the discharge door. In the cooling cavity, the normalizing furnace body further comprises a support and a conveying roller fixed on the support for conveying. The cooling cavity comprises a cooling piece for accelerating cooling and heat dissipation. The cooling piece is fixedly installed on the support. The structure utilizes the airflow generated by the air cooling piece and the water mist sprayed by the micro-mist spray head to form an air-mist two-phase flow with more uniform temperature and humidity. The water mist is fully vaporized, and the cooling is uniform. Meanwhile, the sandglass-shaped structure design of the flow guide cover uniformly diffuses the airflow, effectively avoids the local rapid cooling of the workpiece surface from leaving residual stress with uneven distribution inside, and influences the workpiece quality.

Description

Technical Field

[0001] This invention relates to the field of metal heat treatment cooling system technology, specifically a normalizing furnace based on rapid cooling technology. Background Technology

[0002] A normalizing furnace is a medium-sized industrial kiln, long and narrow in shape. It is mainly used for heat treatment of metal workpieces after forging and is one of the main pieces of equipment in metal processing workshops. Normalizing is a metal heat treatment process in which steel parts are heated to above the critical temperature, held at that temperature for a period of time, and then taken out of the furnace to be cooled in the air.

[0003] Current normalizing furnaces heat steel to its critical temperature and then cool it in air. This method suffers from several problems: slow cooling rate, uneven cooling, insufficient cooling medium flow, uncontrollable cooling rate, and low output. The reasons are that this cooling method relies entirely on natural heat dissipation, resulting in inconsistent heat dissipation efficiency at different locations, seasonal temperature fluctuations, long production cycles, and numerous uncontrollable factors.

[0004] Therefore, there is an urgent need to develop a normalizing furnace based on rapid cooling technology to solve the problems of slow cooling speed and uneven cooling in the existing technology. Summary of the Invention

[0005] The purpose of this invention is to provide a normalizing furnace based on rapid cooling technology, which can fully mix airflow and water mist through the cooperation of a high-speed rotating fan and a spray component in the cooling chamber, resulting in uniform cooling and effectively avoiding the problem of local rapid cooling. Furthermore, when the high-speed airflow flows over the surface of the high-temperature workpiece, it can effectively break through the boundary layer of the workpiece surface, remove more heat, and improve cooling efficiency, thereby solving the problems of slow cooling speed and uneven cooling mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A normalizing furnace based on rapid cooling technology includes a normalizing furnace body. The furnace body is internally divided into a heating chamber for normalizing workpieces and a cooling chamber for cooling workpieces. A discharge door is slidably installed between the heating chamber and the cooling chamber, separating the heating chamber and the cooling chamber. The normalizing furnace body also includes a support frame and a conveying roller fixed on the support frame for conveying. The support frame and the conveying roller are both provided inside the heating chamber and the cooling chamber. The cooling chamber includes a cooling component for accelerating cooling and heat dissipation, which is fixedly installed on the support frame. The cooling component includes an air-cooled component for blowing air to dissipate heat, a spray component for cooperating with the cold air, and a guide shroud for improving the heat dissipation effect. The air-cooled component and the guide shroud are both fixedly installed on the lower inner side of the bracket. The lower end of the guide shroud covers the upper outer side of the air-cooled component, and the spray component is fixedly installed inside the guide shroud.

[0007] By adopting the above technical solution, through the cooperation of the air-cooling component and the spraying component, the high-speed rotating fan will strongly stir and mix the water mist and air to form a two-phase flow of air mist with more uniform temperature and humidity. The air mist two-phase flow formed by the guide hood is gathered and divided, so that the airflow is more evenly diffused across the entire width of the material, avoiding excessive or insufficient local airflow and achieving uniform cooling.

[0008] As a further aspect of the present invention: the structure of the flow guide is hourglass-shaped, the lower end of the hourglass-shaped flow guide has a contraction section, the upper end of the hourglass-shaped flow guide has an expansion section, and spray components are fixedly installed on both the contraction section and the expansion section.

[0009] By adopting the above technical solution, the contraction section accelerates the airflow and enhances the mixing of wind and water mist, while the expansion section reduces the flow velocity and increases the static pressure, so that the two-phase flow of air and mist covers the bottom surface of the workpiece with a uniform velocity field, making it less likely to generate turbulent dead zones.

[0010] As a further aspect of the present invention: the air-cooling component comprises multiple fans, which are mounted at the bottom of the bracket and arranged in an array, and the air guide is fixedly mounted on the bracket and located above the fans, with the constriction section of the air guide covering the upper exterior of all the fans.

[0011] By adopting the above technical solution, multiple fan arrays are distributed to form a uniform air intake velocity field, eliminating cooling stripes caused by excessively high or low local wind speeds. The air guide further homogenizes the air speed and increases the total pressure by utilizing the contraction acceleration effect.

[0012] As a further aspect of the present invention, the ratio of the minimum inner cross-sectional area of ​​the constricted section of the air guide to the total effective air outlet area of ​​all fans is 0.8:1 to 1.2:1.

[0013] By adopting the above technical solutions, the airflow transitions to near constant speed or slight acceleration, minimizing flow loss and allowing the fan to maintain optimal airflow and air pressure.

[0014] As a further embodiment of the present invention: the expansion section of the flow guide is directly opposite the bottom surface of the workpiece, and the horizontal cross-sectional area of ​​the expansion section of the flow guide is larger than the horizontal projected area of ​​the workpiece; at least one set of spray elements is fixedly provided on the inner sidewall of the waist contraction section and the expansion section of the flow guide.

[0015] By adopting the above technical solution, it is ensured that the mist from the nozzle completely covers the bottom surface of the workpiece, with no weak cooling areas at the edges, thus avoiding uneven hardness or microstructure caused by local lack of cooling.

[0016] As a further aspect of the present invention: the vertical distance between the upper outlet of the expansion section of the flow guide and the conveying roller is 10mm to 50mm, and the expansion angle α of the expansion section of the flow guide is ≤9°, so as to ensure that the gas-mist two-phase flow does not produce obvious separation in the expansion section, forming a wall adhesion effect, so that the gas-mist two-phase flow flows uniformly close to the bottom surface of the workpiece.

[0017] By adopting the above technical solution, the small gap allows the air jet to directly impact the bottom surface of the workpiece before significant diffusion and attenuation, avoiding the loss of cold energy; it also leaves enough flow cross section to not obstruct the passage of the workpiece and the discharge of hot steam, making it easy to move relative to the workpiece. The small-angle expansion can prevent the separation of the airflow boundary layer, so that the air-mist two-phase flow forms a "wall-attached effect", flows stably close to the bottom surface of the workpiece, and forms a large-area attached jet forced convection, improving the heat transfer coefficient.

[0018] As a further aspect of the present invention: the spraying component includes a micro-mist nozzle and a water supply pipe for supplying water to the nozzle. The water supply pipe passes through the outer wall of the flow guide and is fixedly installed inside the flow guide. The micro-mist nozzle is fixedly installed on the section of the water supply pipe located inside the flow guide.

[0019] As a further aspect of the present invention: the spray direction of the micro-mist nozzle is at an angle of β (0°<β≤30°) with the airflow direction, and is used to generate water mist with a particle size ≤50μm.

[0020] By adopting the above technical solution, the small-angle co-current spraying makes the relative velocity of the water mist initial velocity direction with the airflow small, and the mist droplets are easy to move with the airflow and are not easy to impact the wall surface and condense, ensuring that the water mist vaporizes fully and cools evenly, effectively avoiding the residual stress left inside the workpiece due to local rapid cooling of the surface.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: Compared with the prior art which only uses a fan to blow directly, the present invention uses a combination of air-cooled components and spray components. It can choose to use a fan to blow air for heat dissipation or a spray component to spray for heat dissipation according to the workpiece. It can also combine the fan and the spray. The fan rotation strongly stirs and mixes the water mist to form a two-phase flow of air and mist with more uniform temperature and humidity. The water mist is fully vaporized and cooled evenly, thus avoiding local rapid cooling. Furthermore, the structure of the guide shroud allows the airflow to reach its maximum speed when passing through the narrowest "waist" of the shroud. When the higher-speed airflow flows over the surface of the high-temperature workpiece, it can effectively break through the boundary layer of the workpiece surface and carry away more heat, thereby significantly improving the cooling efficiency.

[0022] Other features and advantages of the present invention will be disclosed in detail in the following detailed description and accompanying drawings. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure in an embodiment of the present invention; Figure 2 This is a side view of the internal structure of the normalizing furnace in an embodiment of the present invention; Figure 3 This is a top view of the cooling component structure in an embodiment of the present invention; Figure 4 This is a side view of the internal structure of the cooling component in an embodiment of the present invention.

[0024] The figures are labeled as follows: 1. Main body of the normalizing furnace; 2. Heating chamber; 3. Cooling chamber; 4. Discharge gate; 5. Support; 6. Conveyor roller; 7. Cooling component; 8. Air-cooled component; 801. Fan; 9. Spraying component; 901. Micro-mist nozzle; 902. Water supply pipe; 10. Flow guide; 101. Contraction section; 102. Expansion section. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] In this embodiment of the invention, a normalizing furnace based on rapid cooling technology is described below. Figure 1-4As shown, the furnace includes a normalizing furnace body 1, which is internally divided into a heating chamber 2 for normalizing the workpiece and a cooling chamber 3 for cooling the workpiece. A discharge gate 4 is slidably installed between the heating chamber 2 and the cooling chamber 3, separating them. Photoelectric switches are installed in both the cooling chamber 2 and the heating chamber 3. These photoelectric switches, specifically E3Z-D61 type through-beam photoelectric switches, are installed at the outlet of the heating chamber and connected to a reduction motor on the conveyor roller 6. This allows control of the conveyor roller 6's workpiece transport. A hydraulic telescopic rod is installed on the top of the normalizing furnace body 1, which raises and lowers the discharge gate 4 by pulling a rope. The workpiece is placed on a tray and moves on the conveyor roller 6. The length of the tray is greater than the distance between the farthest ends of the three conveyor rollers 6. The cooling components 7 include an air-cooled component 8 for heat dissipation and a matching component. The cooling spray element 9 and the air guide shroud 10 for improving heat dissipation are fixedly installed on the lower inner side of the bracket 5. The lower end of the air guide shroud 10 covers the upper outer side of the cooling element 8. The spray element 9 is fixedly installed inside the air guide shroud 10. A water receiving tray is set at the bottom of the cooling chamber 3 to collect and discharge the generated wastewater. The cooling chamber 3 is equipped with a temperature sensor and a humidity sensor. The temperature sensor is a PT100 platinum resistance thermometer, and the humidity sensor is a HIH-4000 series sensor. The temperature sensor and humidity sensor are electrically connected to a controller. The controller is a PLC programmable logic controller. Its output terminal is connected to the fan motor and the regulating valve through a relay. The controller adjusts the speed of the fan 801 and the spray volume of the micro-mist nozzle 901 according to the sensor feedback to maintain the workpiece surface in a "completely vaporized" state.

[0027] See Figure 1-4 As shown, four fans 801 are evenly distributed on the inner bottom left, lower left, upper right, and lower right sides of the bracket 5. The guide shroud 10 is hourglass-shaped, with a larger diameter at the top and bottom ends and a smaller diameter in the middle. The diameter of the constriction section 101 of the guide shroud 10 is larger than the distribution area of ​​the fans 801, and the diameter of the expansion section 102 of the guide shroud 10 is larger than the area of ​​the bottom of the workpiece. The expansion angle α of the expansion section 102 of the guide shroud 10 is ≤9°. Specific preferred comparisons are as follows: In practical applications, the airflow may not be perfectly axisymmetric, and the roughness of the shroud wall and the turbulence of the incoming flow can reduce the separation angle by 1-2°. Choosing α=7° allows for the maximum expansion range without triggering significant separation, at the waist velocity V of the shroud 10. max At a given time, the exit velocity of the expansion section 102 at α=7° is approximately 0.7-0.8 times the inlet (waist) velocity, still significantly higher than the free jet decay rate. When this velocity impacts the workpiece, the boundary layer thickness can be compressed by 30-50%, resulting in a significant increase in the heat transfer coefficient.

[0028] The spray direction of the micro-mist nozzle 901 installed inside the deflector 10 is at an angle β to the airflow direction, where 0° < β ≤ 30°, and is used to generate water mist with a particle size ≤ 50 μm. Specifically, β = 20° (allowable error ± 2°). For example, the airflow velocity in the converging section 101 of the deflector 10 accelerates from the fan outlet (approximately 5-10 m / s) to the waist (up to 20-30 m / s). At a distance of 10-20 mm downstream of the nozzle, the airflow velocity is already sufficiently high. A 20° angle allows the water mist jet to enter the high-speed zone while avoiding direct spraying onto the opposite wall (because the width of the contraction section gradually decreases, the distance between the water mist trajectory and the wall is shortened by more than 50% at 30°, so β=20° is chosen to ensure that the high-density fine water mist enters the main airflow while avoiding water film loss and droplet deposition; the water supply pipe 902 is equipped with a flow regulating valve and a pressure sensor. The flow regulating valve adjusts the water spray volume according to the temperature, material or thickness of the workpiece so that the water mist is completely vaporized on the workpiece surface without forming a water film).

[0029] Understandably, when the material tray reaches the photoelectric switch position at the discharge port within the heating chamber 2 of the furnace body 1, the discharge gate 4 rises and opens. The discharge reducer in the heating chamber 2 and the reducer in the cooling chamber 3 drive the conveyor roller 6 to transport the material tray to the photoelectric position within the cooling chamber 3. After photoelectric sensing, the reducer stops, and the discharge gate 4 descends and closes. At this time, the air-cooling component 8 within the cooling chamber 3 can be started independently, using the high-speed rotation of the fan 801 to blow air and dissipate heat from the workpiece; alternatively, the regulating valve on the water supply pipe 902 can be opened independently, and the micro-mist nozzle 901 located within the cooling chamber 3 on the water supply pipe 902 can begin spraying water, accelerating the heat dissipation of the workpiece through the water mist sprayed by the micro-mist nozzle 901; or, the air-cooling component 8 can be combined with the spray component 9, and used in conjunction with the guide shroud 10 for efficient aerosol cooling: the airflow generated by the high-speed rotation of the fan 801 enters the contraction section 101 of the hourglass-shaped guide shroud 10, is gathered and accelerated, and simultaneously... The ultrafine water mist (particle size ≤ 50 μm) sprayed by the micro-mist nozzles 901 arranged in the contraction section 101 is fully mixed to form a high-speed gas-mist two-phase flow with more uniform temperature and humidity. Then, the two-phase flow is smoothly discharged through the expansion section 102 with a small expansion angle (α ≤ 9°). With the help of the wall effect, it flows uniformly close to the bottom surface of the workpiece, so that the water mist evaporates and vaporizes rapidly near the surface of the workpiece. While achieving full area coverage, it greatly enhances convection and latent heat exchange. The water mist vaporizes fully, the cooling rate is high and the uniformity is excellent, effectively avoiding the problem of local rapid cooling.

[0030] This invention provides a normalizing furnace based on rapid cooling technology. The furnace utilizes a high-speed rotating fan and spray nozzle within the cooling chamber to thoroughly mix airflow and water mist, ensuring uniform cooling and effectively avoiding localized rapid cooling. Furthermore, the high-speed airflow effectively breaks through the boundary layer of the workpiece surface, carrying away more heat and improving cooling efficiency. Simultaneously, the hourglass-shaped structure of the guide shroud maximizes the airflow velocity when passing through the narrowest part of the shroud. This higher-speed airflow further breaks through the boundary layer of the high-temperature workpiece surface, carrying away even more heat and enhancing cooling efficiency.

[0031] 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.

[0032] 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. A normalizing furnace based on rapid cooling technology, comprising a normalizing furnace body (1), wherein the furnace body (1) is internally divided into a heating chamber (2) for normalizing workpieces and a cooling chamber (3) for cooling the workpieces, wherein a discharge door (4) is slidably installed between the heating chamber (2) and the cooling chamber (3), thereby separating the heating chamber (2) and the cooling chamber (3), characterized in that, The main body (1) of the furnace also includes a support (5) and a conveyor roller (6) fixed on the support (5) for conveying. The heating chamber (2) and the cooling chamber (3) are both equipped with a support (5) and a conveyor roller (6). The cooling chamber (3) includes a cooling component (7) for accelerating cooling and heat dissipation. The cooling component (7) is fixedly installed on the support (5). The cooling component (7) includes a wind-cooled component (8) for blowing air to dissipate heat, a spray component (9) for cooperating with the cold air, and a guide shroud (10) for improving the heat dissipation effect. The wind-cooled component (8) and the guide shroud (10) are both fixedly installed on the lower inner side of the bracket (5). The lower end of the guide shroud (10) is covered on the upper outer side of the wind-cooled component (8), and the spray component (9) is fixedly installed inside the guide shroud (10).

2. A normalizing furnace based on rapid cooling technology according to claim 1, characterized in that, The structure of the flow guide (10) is hourglass-shaped. The lower end of the hourglass-shaped flow guide (10) has a contraction section (101), and the upper end of the hourglass-shaped flow guide (10) has an expansion section (102). Spraying components (9) are fixedly installed on both the contraction section (101) and the expansion section (102).

3. A normalizing furnace based on rapid cooling technology according to claim 1, characterized in that, The air-cooled component (8) consists of multiple fans (801). The fans (801) are mounted on the bottom of the bracket (5) and arranged in an array. The air guide (10) is fixedly mounted on the bracket (5) and located on the upper side of the fans (801). The constriction section (101) of the air guide (10) covers the upper exterior of all the fans (801).

4. A normalizing furnace based on rapid cooling technology according to claim 3, characterized in that, The ratio of the minimum inner cross-sectional area of ​​the constricted section (101) of the shroud (10) to the total effective air outlet area of ​​all fans (801) is 0.8:1 to 1.2:

1.

5. A normalizing furnace based on rapid cooling technology according to claim 2, characterized in that, The expansion section (102) of the flow guide (10) faces the bottom surface of the workpiece, and the horizontal cross-sectional area of ​​the expansion section (102) of the flow guide (10) is greater than the horizontal projected area of ​​the workpiece. At least one set of spray elements (9) is fixedly provided on the inner sidewall of the waist contraction section (101) and the expansion section (102) of the flow guide (10).

6. A normalizing furnace based on rapid cooling technology according to claim 5, characterized in that, The vertical distance between the upper outlet of the expansion section (102) of the flow guide (10) and the conveyor roller (6) is 10mm to 50mm. The expansion angle α of the expansion section (102) of the flow guide (10) is ≤9°, so as to ensure that the two-phase flow of gas and mist does not produce obvious separation in the expansion section, forming a wall adhesion effect, so that the two-phase flow of gas and mist flows uniformly close to the bottom surface of the workpiece.

7. A normalizing furnace based on rapid cooling technology according to claim 5, characterized in that, The spraying component (9) includes a micro-mist nozzle (901) and a water supply pipe (902) for supplying water to the nozzle. The water supply pipe (902) passes through the outer wall of the guide shroud (10) and is fixedly installed inside the guide shroud (10). The micro-mist nozzle (901) is fixedly installed on the section of the water supply pipe (902) located inside the guide shroud (10).

8. A normalizing furnace based on rapid cooling technology according to claim 7, characterized in that, The spray direction of the micro-mist nozzle (901) is at an angle β (0°<β≤30°) with the airflow direction, and is used to generate water mist with a particle size ≤50μm.

Images