Cooling device for high-vacuum heat treatment furnace
By designing a cooling device in the high vacuum heat treatment furnace, and using cold traps and cooling components to condense oil vapor, the problem of oil backflow from the diffusion pump is solved, ensuring the cleanliness of the vacuum chamber and the workpiece, and enabling the reuse of oil vapor.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI HUISEN MTH INDAL FURNACES
- Filing Date
- 2025-05-15
- Publication Date
- 2026-05-12
AI Technical Summary
In existing high vacuum heat treatment furnaces, the oil backflow phenomenon of diffusion pumps leads to contamination of the vacuum chamber and workpieces, and there is a lack of effective prevention devices or methods.
Design a cooling device including a cold trap and a main valve. The cold trap is connected to the sealed cavity of a high vacuum heat treatment furnace and an oil diffusion pump through the main valve. The cold trap is equipped with heat sinks and cooling coils to condense oil vapor and prevent it from entering the vacuum cavity.
It effectively prevents oil vapor from entering the vacuum chamber, maintains high cleanliness, avoids contaminating workpieces, and enables the reuse of oil vapor.
Smart Images
Figure CN224227126U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of vacuum heat treatment furnace technology, and in particular to a cooling device for a high vacuum heat treatment furnace. Background Technology
[0002] For high-vacuum heat treatment furnaces with high-vacuum metal shielding hot zones, the ultimate vacuum level is generally required to be 10. -6 In the MBar range, to achieve this high vacuum, a relatively economical and reliable method is to use an oil diffusion pump to evacuate the sealed vacuum chamber.
[0003] Since the operation of an oil diffusion pump is based on the principle of oil diffusion, during its operation, some high-temperature oil vapor will inevitably diffuse into the vacuum chamber through the vacuum pipe. This phenomenon is called diffusion pump backflow, which can contaminate the inside of the vacuum chamber and the workpiece to be heat-treated.
[0004] Currently, there is no effective device or method to prevent oil backflow from the diffusion pump in a high-vacuum heat treatment furnace. Therefore, there is a need to provide a cooling device for a high-vacuum heat treatment furnace that can solve the problem of the lack of a device in the prior art for preventing oil backflow from the diffusion pump in a high-vacuum heat treatment furnace. Summary of the Invention
[0005] The purpose of this invention is to provide a cooling device for a high vacuum heat treatment furnace, which can solve the problem that there is no device in the prior art to prevent oil backflow from the diffusion pump of a high vacuum heat treatment furnace.
[0006] This utility model is implemented as follows:
[0007] A cooling device for a high vacuum heat treatment furnace includes a cold trap and a main valve; one end of the cold trap is connected to the sealed cavity of the high vacuum heat treatment furnace through the main valve, and the other end of the cold trap is connected to an oil diffusion pump, so that the sealed cavity of the high vacuum heat treatment furnace can be connected to the oil diffusion pump through the main valve and the cold trap; the workpiece is placed in the sealed cavity of the high vacuum heat treatment furnace.
[0008] The cold trap includes an inlet flange, a sealed cylinder, a cooling assembly, and an outlet flange. The sealed cylinder is a hollow cylinder structure with openings at both ends. The inlet flange and the outlet flange are respectively installed at the two open ends of the sealed cylinder, so that one open end of the sealed cylinder is connected to the main valve through the inlet flange, and the other open end of the sealed cylinder is connected to the oil diffusion pump through the outlet flange. The cooling assembly is disposed inside the sealed cylinder and located between the inlet flange and the outlet flange.
[0009] The cooling assembly includes heat sinks, with several heat sinks spaced apart on the inner wall of the sealed cylinder. When airflow and oil vapor flow through the sealed cylinder, they come into contact with the heat sinks.
[0010] The heat sink has a bent structure, with the oil diffusion pump positioned with the downward-bent side of the heat sink facing downwards.
[0011] The cooling assembly also includes a cooling coil, which has a serpentine structure that covers the cross-section of the sealed cylinder. Both ends of the cooling coil extend to the outside of the sealed cylinder and are respectively equipped with an inlet and an outlet, so that cooling water is circulating inside the cooling coil through the inlet and outlet.
[0012] The cooling coil is fixedly connected to the heat sink.
[0013] Compared with the prior art, this utility model has the following advantages:
[0014] 1. This utility model, by incorporating a cold trap, achieves cooling and heat dissipation by exchanging heat with the airflow and oil vapor flowing through the sealed cylinder through heat sinks and cooling coils. The condensed oil vapor accumulates into oil droplets and drips down the heat sinks to the oil diffusion pump below, facilitating the reuse of oil droplets. It also effectively prevents oil vapor from entering the sealed cavity of the high vacuum heat treatment furnace and causing contamination to the inside of the furnace and the workpieces therein. This solves the problem of oil backflow from the diffusion pump in the high vacuum heat treatment furnace and meets the high cleanliness requirements of the high vacuum heat treatment furnace.
[0015] 2. Because this utility model is equipped with heat sinks and cooling coils, the bent structure of the heat sinks and the serpentine structure of the cooling coils can increase the heat exchange contact area with the airflow and oil vapor, thereby improving the cooling effect of the airflow and oil vapor, and effectively preventing oil vapor from entering the sealed cavity of the high vacuum heat treatment furnace. In addition, the cooling coils can simultaneously cool the heat sinks, further improving the condensation effect of the heat sinks on oil vapor. Attached Figure Description
[0016] Figure 1 This is an installation diagram of the cooling device for a high vacuum heat treatment furnace according to this utility model;
[0017] Figure 2 This is a top view of the cold trap in the cooling device of the high vacuum heat treatment furnace of this utility model;
[0018] Figure 3 yes Figure 2 Sectional view of AA.
[0019] In the diagram, 1 is the cold trap, 2 is the sealed cavity of the high vacuum heat treatment furnace, 3 is the oil diffusion pump, 4 is the main valve, 5 is the workpiece, 6 is the air inlet flange, 7 is the sealed cylinder, 8 is the heat sink, 9 is the cooling coil, 10 is the water inlet, 11 is the water outlet, and 12 is the air outlet flange. Detailed Implementation
[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0021] Please see the appendix Figure 1 A cooling device for a high vacuum heat treatment furnace includes a cold trap 1 and a main valve 4; one end of the cold trap 1 is connected to the sealed cavity 2 of the high vacuum heat treatment furnace through the main valve 4, and the other end of the cold trap 1 is connected to an oil diffusion pump 3, so that the sealed cavity 2 of the high vacuum heat treatment furnace can be connected to the oil diffusion pump 3 through the main valve 4 via the cold trap 1; the workpiece 5 is placed inside the sealed cavity 2 of the high vacuum heat treatment furnace.
[0022] A cold trap 1 is installed between the oil diffusion pump 3 and the sealed cavity 2 of the high vacuum heat treatment furnace to cool the oil vapor of the oil diffusion pump 3, thereby preventing the oil vapor from diffusing into the sealed cavity 2 of the high vacuum heat treatment furnace along the vacuum pipe. This solves the problem of oil backflow from the diffusion pump in the prior art and effectively prevents the oil vapor entering the sealed cavity 2 of the high vacuum heat treatment furnace from contaminating the interior of the sealed cavity 2 of the high vacuum heat treatment furnace and the workpiece 5 inside.
[0023] The main valve 4 controls the connection or disconnection between the oil diffusion pump 3 and the sealed cavity 2 of the high vacuum heat treatment furnace by opening and closing. When the main valve 4 is open, the oil diffusion pump 3 is connected to the sealed cavity 2 of the high vacuum heat treatment furnace, and the sealed cavity 2 of the high vacuum heat treatment furnace can be evacuated by the oil diffusion pump 3. When the main valve 4 is closed, the oil diffusion pump 3 is disconnected from the sealed cavity 2 of the high vacuum heat treatment furnace, so that the sealed cavity 2 of the high vacuum heat treatment furnace can be kept in a vacuum state, which is convenient for heat treatment of the workpiece 5.
[0024] Please see the appendix Figure 2 and attached Figure 3 The cold trap 1 includes an inlet flange 6, a sealed cylinder 7, a cooling assembly, and an outlet flange 12. The sealed cylinder 7 is a hollow cylinder structure with openings at both ends. The inlet flange 6 and the outlet flange 12 are respectively installed at the two open ends of the sealed cylinder 7, so that one open end of the sealed cylinder 7 is connected to the main valve 4 through the inlet flange 6, and the other open end of the sealed cylinder 7 is connected to the oil diffusion pump 3 through the outlet flange 12. The cooling assembly is disposed inside the sealed cylinder 7 and located between the inlet flange 6 and the outlet flange 12.
[0025] Preferably, the two open ends of the sealed cylinder 7 are vacuum-sealed to the inlet flange 6 and the outlet flange 12 to achieve a reliable seal. The inlet flange 6 is connected to the flange structure at the bottom of the main valve 4 through a flange structure, and the outlet flange 12 is connected to the flange structure at the top of the oil diffusion pump 3 through a flange structure, making the structure of the cold trap 1 simple, easy to disassemble and assemble, and with high connection reliability and airtightness.
[0026] The cooling assembly is used to cool the airflow and oil vapor flowing through the sealed cylinder 7, and to prevent hot oil vapor from entering the sealed cavity 2 of the high vacuum heat treatment furnace, thereby avoiding oil vapor contamination of the interior of the sealed cavity 2 of the high vacuum heat treatment furnace and the workpiece 5 inside the sealed cavity 2 of the high vacuum heat treatment furnace.
[0027] Please see the appendix Figure 2 and attached Figure 3 The cooling assembly includes heat sinks 8, with several heat sinks 8 arranged at intervals on the inner wall of the sealed cylinder 7. When airflow and oil vapor flow through the sealed cylinder 7, they come into contact with the heat sinks 8.
[0028] By setting the heat sink 8, the high-temperature airflow and oil vapor can come into contact with the low-temperature heat sink 8 when flowing through the sealed cylinder 7 and exchange heat, thereby achieving the effect of heat dissipation and cooling. This prevents oil vapor from entering the sealed cavity 2 of the high vacuum heat treatment furnace and contaminating the inside of the sealed cavity 2 and the workpiece 5 placed inside the sealed cavity 2 of the high vacuum heat treatment furnace.
[0029] The number of heat sinks 8 and their spacing can be adjusted according to actual heat dissipation requirements.
[0030] Please see the appendix Figure 3 The heat sink 8 has a bent structure, and the oil diffusion pump 3 is positioned with the downward bent surface of the heat sink 8 facing downward.
[0031] The bent structure increases the heat exchange area between the airflow and oil vapor and the heat sink 8 when the airflow and oil vapor flow through the sealed cylinder 7, thereby effectively cooling the airflow and oil vapor. The oil vapor condensed by the heat sink 8 accumulates on the heat sink 8 to form oil droplets, which are then guided downwards by the bent heat sink 8 and drip into the oil diffusion pump 3, facilitating the reuse of the oil droplets.
[0032] Please see the appendix Figure 2 The cooling assembly also includes a cooling coil 9, which has a serpentine structure and is fully distributed across the cross-section of the sealed cylinder 7. Both ends of the cooling coil 9 extend to the outside of the sealed cylinder 7 and are respectively equipped with an inlet 10 and an outlet 11, so that cooling water is circulating inside the cooling coil 9 through the inlet 10 and the outlet 11.
[0033] Please see the appendix Figure 2 The cooling coil 9 is fixedly connected to the heat sink 8.
[0034] The cooling coil 9 is in contact with the heat sink 8, and the low-temperature cooling water circulating inside the cooling coil 9 can dissipate heat from the heat sink 8, improving the heat dissipation and cooling effect of the heat sink 8 on airflow and oil vapor. It also facilitates the installation of the cooling coil 9 inside the sealed cylinder 7.
[0035] Please see the appendix Figure 1 To be continued Figure 3 The method of use and working principle of this utility model are as follows:
[0036] When the workpiece 5 to be heat-treated in the sealed cavity 2 of the high-vacuum heat treatment furnace requires a vacuum process, the main valve 4 opens, connecting the oil diffusion pump 3 to the sealed cavity 2 of the high-vacuum heat treatment furnace, allowing the oil diffusion pump 3 to evacuate the sealed cavity 2. When the main valve 4 closes, the connection between the sealed cavity 2 of the high-vacuum heat treatment furnace and the oil diffusion pump 3 is cut off, maintaining a vacuum state inside the sealed cavity 2, allowing the workpiece 5 to be heat-treated under vacuum conditions.
[0037] When vacuuming, the airflow comes into contact with the heat sink 8 when passing through the sealed cylinder 7, achieving heat exchange and cooling. At the same time, the oil vapor in the oil diffusion pump 3 is also condensed when passing through the heat sink 8, thus preventing the oil vapor from entering the sealed cavity 2 of the high vacuum heat treatment furnace and contaminating its interior and the workpiece 5 to be heat treated.
[0038] Meanwhile, cooler water enters the cooling coil 9 through the inlet 10. As the airflow and oil vapor pass through the sealed cylinder 7, they simultaneously contact the cooling coil 9 for further heat exchange and cooling, ensuring that oil vapor does not enter the sealed cavity 2 of the high-vacuum heat treatment furnace and cause contamination. Furthermore, the cooling coil 9 is fixedly connected to the heat sink 8, allowing the cooling coil 9 to simultaneously dissipate heat from the heat sink 8, improving the cooling effect of the heat sink 8 on the airflow and oil vapor. The heated water flows out from the outlet 11, is cooled externally, and then circulates back to the inlet 10, achieving a circulating cooling function.
[0039] When hot oil vapor comes into contact with the cold heat sink 8 and cooling coil 9, the oil vapor is cooled and condensed, accumulating on the heat sink 8. The oil vapor accumulates to form oil droplets and drips into the oil diffusion pump 3 below, where it can be reused.
[0040] The above are merely preferred embodiments of the present utility model and are not intended to limit the scope of protection of the present utility model. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the scope of protection of the present utility model.
Claims
1. A cooling device for a high-vacuum heat treatment furnace, characterized in that: It includes a cold trap (1) and a main valve (4); one end of the cold trap (1) is connected to the sealed cavity (2) of the high vacuum heat treatment furnace through the main valve (4), and the other end of the cold trap (1) is connected to the oil diffusion pump (3), so that the sealed cavity (2) of the high vacuum heat treatment furnace can be connected to the oil diffusion pump (3) through the cold trap (1) via the main valve (4); the workpiece (5) is placed inside the sealed cavity (2) of the high vacuum heat treatment furnace.
2. The cooling device for a high-vacuum heat treatment furnace according to claim 1, characterized in that: The cold trap (1) includes an inlet flange (6), a sealed cylinder (7), a cooling assembly, and an outlet flange (12). The sealed cylinder (7) is a hollow cylinder structure with openings at both ends. The inlet flange (6) and the outlet flange (12) are respectively installed at the two open ends of the sealed cylinder (7), so that one open end of the sealed cylinder (7) is connected to the main valve (4) through the inlet flange (6), and the other open end of the sealed cylinder (7) is connected to the oil diffusion pump (3) through the outlet flange (12). The cooling assembly is set inside the sealed cylinder (7) and located between the inlet flange (6) and the outlet flange (12).
3. The cooling device for a high-vacuum heat treatment furnace according to claim 2, characterized in that: The cooling assembly includes heat sinks (8), with several heat sinks (8) arranged at intervals on the inner wall of the sealed cylinder (7). When airflow and oil vapor flow through the sealed cylinder (7), they come into contact with the heat sinks (8).
4. The cooling device for a high-vacuum heat treatment furnace according to claim 3, characterized in that: The heat sink (8) has a bent structure, and the oil diffusion pump (3) is installed with the heat sink (8) bent downwards.
5. The cooling device for a high-vacuum heat treatment furnace according to claim 3, characterized in that: The cooling assembly also includes a cooling coil (9), which has a serpentine structure that covers the cross-section of the sealed cylinder (7). The two ends of the cooling coil (9) extend to the outside of the sealed cylinder (7) and are respectively equipped with an inlet (10) and an outlet (11), so that cooling water is circulating inside the cooling coil (9) through the inlet (10) and the outlet (11).
6. The cooling device for a high-vacuum heat treatment furnace according to claim 5, characterized in that: The cooling coil (9) is fixedly connected to the heat sink (8).