Nitriding furnace capable of improving uniformity of temperature in furnace

Abstract

The invention relates to a nitriding furnace capable of improving temperature uniformity in the furnace, and aims to solve the problems of unsmooth airflow circulation, uneven temperature distribution and the like in the conventional nitriding furnace. The nitriding furnace comprises a furnace shell, a furnace body, a heating device and a plurality of fan systems, stable airflow flowing is formed in the furnace body through reasonable configuration of an air inlet and an air outlet and the synergistic effect of a first fan, a second fan and a third fan, and it is ensured that the temperature of all areas in the furnace is evenly distributed. The heat of the heating device is transferred to the furnace body through air flow in the first chamber, and the second fan and the third fan optimize air flow distribution through air flow circulation in the up-down direction and the front-back direction respectively, so that the temperature dead angle is eliminated. Through optimal combination of airflow and the heating device, the temperature control precision and the heating efficiency of the nitriding furnace are remarkably improved, the uniformity of a nitriding layer and the surface quality of a workpiece are improved, and the nitriding furnace is suitable for the field of metal surface treatment needing high-precision temperature control.

Description

Technical Field

[0001] This application relates to the technical field of metal treatment, and specifically to a nitriding furnace for improving the temperature uniformity in the furnace. Background Art

[0002] Nitriding treatment is a heat treatment process widely used for surface strengthening of metal materials, mainly used to improve the surface hardness, wear resistance, and corrosion resistance of metals. During the operation of traditional nitriding furnaces, due to problems such as poor air flow circulation, low heating system efficiency, and uneven temperature distribution, this usually leads to uneven temperature in the furnace, thereby affecting the quality and hardness uniformity of the nitrided layer of the workpiece. In addition, traditional nitriding furnaces have high energy consumption and cannot effectively utilize energy, resulting in high production costs. Therefore, how to improve the temperature uniformity of nitriding furnaces, increase the heating efficiency, and reduce energy consumption has become an urgent problem to be solved in nitriding furnace technology. Application Content

[0003] This application provides a nitriding furnace for improving the temperature uniformity in the furnace, which improves the temperature uniformity in the nitriding furnace by optimizing the air flow and heating efficiency.

[0004] The nitriding furnace for improving the temperature uniformity in the furnace provided by this application includes: A furnace shell; A furnace body, arranged inside the furnace shell. There is a first chamber between the outer wall of the furnace body and the inner wall of the furnace shell. A first air inlet and a first air outlet are arranged on the inner wall of the furnace shell. The furnace body is made of heat-conducting material. A second chamber for placing workpieces is arranged inside the furnace body. A second air inlet, a second air outlet, a third air outlet, and a third air inlet are arranged on the inner wall of the furnace body; A heating device, arranged in the first chamber; A first fan, arranged on the furnace shell, used to suck the air in the first chamber out from the first air outlet and then return it to the first chamber from the first air inlet, so that the air flow continuously flows in the first chamber. When the air flow flows, it continuously transfers the heat of the heating device to the furnace body; A second fan, arranged on the furnace body, used to suck the air in the second chamber out from the second air outlet and then return it to the second chamber from the second air inlet, so as to form an air flow flowing in the up and down direction in the second chamber; A third fan, arranged on the furnace body, used to suck the air in the second chamber out from the third air outlet and then return it to the second chamber from the third air inlet, so as to form an air flow flowing in the front and back direction in the second chamber.

[0005] Preferably, there are two first air inlets. Both of the two first air inlets are located at the bottom of the furnace shell and close to the front side of the furnace shell. The two first air inlets are respectively located on the left and right sides of the furnace body. The first air outlet is located at the rear side of the furnace shell and close to the top of the furnace shell.

[0006] Preferably, there are multiple second air inlets which are divided into two groups. The two groups of second air inlets are respectively located on the left and right inner walls of the furnace body and close to the bottom of the furnace body. Each group of second air inlets is arranged at intervals in the front-back direction of the furnace body. There are two second air outlets, and the two second air outlets are both located at the top of the furnace body and arranged at intervals in the front-back direction of the furnace body. A second fan is arranged on each second air outlet.

[0007] Preferably, there are two third air outlets, and the two third air outlets are respectively located on the upper and lower inner walls of the furnace body and close to the front side of the furnace body. There are multiple third air inlets which are arranged in an array on the rear side of the furnace body.

[0008] Preferably, the heating device includes two groups of heating rods. The two groups of heating rods are respectively close to the outer walls on the left and right sides of the furnace body. Each group of heating rods is arranged at intervals in the front-back direction of the furnace body.

[0009] Preferably, the heating rods are inserted into the furnace shell from the outside of the furnace shell so that the heating parts of the heating rods extend into the first chamber.

[0010] Preferably, a connecting plate and a bracket are arranged on the top of the furnace shell. The connecting plate is connected to the tops of all the heating rods. A driving device is arranged on the bracket. The driving device is used to drive the connecting plate to move up and down so as to drive all the heating rods to move synchronously, so that the heating rods are switched between a first state and a second state. When the heating rods are in the first state, the heating rods are inserted into the furnace shell, and the heating parts of the heating rods extend into the first chamber. When the heating rods are in the second state, the heating rods are separated from the furnace shell, and the holes on the furnace shell for inserting the heating rods are opened so that the first chamber is communicated with the external atmosphere. A switching valve is arranged at the air inlet end of the first fan. The switching valve can selectively connect the air inlet end of the first fan to the first chamber or the external atmosphere.

[0011] The present invention provides a nitriding furnace which improves the temperature uniformity in the nitriding furnace by optimizing the furnace body structure, heating device and air flow circulation system. Its advantages are mainly reflected in the following aspects: 1. By reasonably arranging the air inlets and outlets and the fan system, the present invention can form a stable and uniform air flow in the furnace body. The air flow circulation in the up-down and front-back directions effectively eliminates the temperature dead corners and ensures the uniform distribution of the temperature in each area of the furnace, thus greatly improving the temperature control accuracy and the surface quality of the workpiece during the nitriding process.

[0012] 2. The nitriding furnace of the present invention adopts the coordinated operation of the heating device and the fan system. The air flow circulation in the first chamber and the second chamber can transfer the heat of the heating device to the furnace body as evenly as possible, reducing the waste of heat. The external insertion method of the heating rods also improves the heat transfer efficiency, reduces the energy consumption as a whole, and improves the energy utilization rate.

[0013] 3. In the design of the present invention, the air flow is ingeniously divided into multiple directions. The second fan and the third fan ensure the full mixing and uniform transfer of the air flow in the furnace through the air flow in different directions (up and down, front and back). This air flow mode effectively avoids the problem of uneven temperature caused by poor air flow and improves the operation stability of the nitriding furnace. Description of the Drawings

[0014] Figure 1 Structural schematic diagram of the nitriding furnace in the embodiment; Figure 2 Structural schematic diagram of the nitriding furnace from another perspective in the embodiment; Figure 3 Structural schematic diagram of the nitriding furnace in the embodiment after removing the top plate of the furnace shell; Figure 4 Structural schematic diagram of the nitriding furnace in the embodiment after removing the top plate of the furnace shell from another perspective; Figure 5 Structural schematic diagram of the top plate of the furnace shell; Figure 6 Structural schematic diagram of the furnace body; Figure 7 Structural schematic diagram of the furnace body from another perspective; Figure 8 Top view of the furnace body; Figure 9 For Figure 8 A - A sectional view in Figure 10 For Figure 9 B - B sectional view in Figure 11 For Figure 9 C - C sectional view in Figure 12 Structural schematic diagram of the top plate of the furnace shell in another embodiment.

[0015] Description of the reference numerals: 10, furnace shell; 11, first chamber; 111, first air inlet; 112, first air outlet; 12, top plate; 121, connecting plate; 122, bracket; 123, electric push rod; 20, furnace body; 21, second chamber; 22, second air inlet; 23, second air outlet; 24, third air outlet; 25, third air inlet; 30, heating device; 31, heating rod; 40, first fan; 41, first pipeline; 50, second fan; 51, motor; 52, impeller; 60, third fan; 61, second pipeline; 62, motor; 63, impeller; 70, furnace door. Detailed implementation manners

[0016] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description will be given to the specific embodiments of the present invention with reference to the accompanying drawings.

[0017] As Figures 1 to 11 , the nitriding furnace for improving the temperature uniformity in the furnace in this embodiment includes a furnace shell 10, a furnace body 20, a heating device 30, a first blower 40, a second blower 50 and a third blower 60.

[0018] The furnace body 20 is arranged inside the furnace shell 10. The front sides of both the furnace shell 10 and the furnace body 20 are openings. A furnace door 70 is arranged on the front side of the furnace body 20 in a manner that can be opened and closed. When the furnace door 70 is opened, it can simultaneously open the openings of both the furnace shell 10 and the furnace body 20. At this time, the workpiece to be nitrided can be put into the furnace body 20. When the furnace door 70 is closed, it can simultaneously seal the openings of both the furnace shell 10 and the furnace body 20. At this time, the workpiece in the furnace body 20 can be nitrided.

[0019] A first chamber 11 is arranged between the outer wall of the furnace body 20 and the inner wall of the furnace shell 10. The heating device 30 is arranged in the first chamber 11. The first chamber 11 includes the regions between the left and right outer walls of the furnace body 20 and the left and right inner walls of the furnace shell 10, and the region between the rear outer wall of the furnace body 20 and the rear inner wall of the furnace shell 10. A first air inlet 111 and a first air outlet 112 are arranged on the inner wall of the furnace shell 10, and both the first air inlet 111 and the first air outlet 112 are communicated with the first chamber 11.

[0020] Specifically, referring to Figures 1 to 4, there are two first air inlets 111, both of which are located at the bottom of the furnace shell 10 and near the front side of the furnace shell 10. The two first air inlets 111 are respectively located on the left and right sides of the furnace body 20. The first air outlet 112 is located at the rear side of the furnace shell 10 and near the top of the furnace shell 10. The first fan 40 is arranged on the furnace shell 10. The air inlet end of the first fan 40 is communicated with the first air outlet 112, and the air outlet end of the first fan 40 is respectively communicated with the two first air inlets 111 through the first pipeline 41. The first fan 40 is used to suck the air in the first chamber 11 out from the first air outlet 112 and then return it to the first chamber 11 through the two first air inlets 111, so that the air flow continuously flows in the first chamber 11. When the air flow flows, it continuously transfers the heat of the heating device 30 to the furnace body 20. Moreover, by arranging two first air inlets 111, and the two first air inlets 111 are located at the bottom of the furnace shell 10 and near the front side of the furnace shell 10, such a design can ensure that the air flow enters from the bottom of the furnace shell 10, forming an air flow cycle from bottom to top. Such a layout helps to evenly heat the air in the furnace body 20 and avoids the phenomenon that the air flow is concentrated in a certain part. Moreover, the two first air inlets 111 are respectively located on the left and right sides of the furnace body 20, which can promote the uniform distribution of air, thereby reducing the problems of poor air flow and heat concentration and effectively improving the overall air flow efficiency. Thus, the heat generated by the heating device 30 can be more evenly transferred into the furnace body 20, which helps to further improve the temperature uniformity in the furnace.

[0021] The furnace body 20 is made of a heat-conducting material, such as stainless steel. A second chamber 21 for placing workpieces to be nitrided is arranged in the furnace body 20.

[0022] A second air inlet 22, a second air outlet 23, a third air outlet 24 and a third air inlet 25 are arranged on the inner wall of the furnace body 20. The second air inlet 22, the second air outlet 23, the third air outlet 24 and the third air inlet 25 are all communicated with the second chamber 21.

[0023] Specifically, refer to Figure 9 、 Figure 10, there are multiple second air inlets 22 which are divided into two groups. The two groups of second air inlets 22 are respectively located on the left and right inner walls of the furnace body 20 and close to the bottom of the furnace body 20. Each group of second air inlets 22 is arranged at intervals in the front-back direction of the furnace body 20. There are two second air outlets 23, and the two second air outlets 23 are both located at the top of the furnace body 20 and arranged at intervals in the front-back direction of the furnace body 20. There are two second blowers 50, and each second air outlet 23 is provided with a second blower 50. The second blower 50 is used to suck the air in the second chamber 21 out from the respective second air outlet 23 and then return it to the second chamber 21 through the multiple second air inlets 22, so as to form an air flow flowing in the up-down direction in the second chamber 21. In this way, dividing the second air inlets 22 into two groups and respectively arranging them on the left and right inner walls of the furnace body 20 and close to the bottom of the furnace body 20 can enhance the air flow circulation in the furnace body 20, ensure that the air can enter the furnace body 20 evenly from the bottom, and flow upward in the furnace body 20. This configuration helps the positive circulation of the air flow and improves the uniformity of the air flow. Moreover, the distribution of the second air inlets 22 helps to avoid the stagnation of local air flow, thereby effectively reducing the temperature deviation. The reasonable layout of the air flow path effectively avoids the temperature difference problem caused by the local air flow blockage, and further improves the temperature control accuracy in the furnace.

[0024] The second blower 50 includes a motor 51 and a wind wheel 52. The motor 51 is connected to the wind wheel 52 to drive the wind wheel 52 to rotate. The motor 51 is arranged outside the furnace shell 10, and the wind wheel 52 is arranged in the first circulation air duct in the furnace body 20. The first circulation air duct is connected to the second chamber 21 through the second air outlet 23 and the second air inlet 22.

[0025] Specifically, referring to Figure 9 、 Figure 11, there are two third air outlets 24, and the two third air outlets 24 are respectively located on the inner walls of the upper and lower sides of the furnace body 20 and close to the front side of the furnace body 20. There are multiple third air inlets 25 and they are distributed in an array on the rear side of the furnace body 20. The third fan 60 is arranged on the furnace body 20. The air inlet side of the third fan 60 is respectively communicated with the two third air outlets 24 through the second pipeline 61, and the air outlet side of the third fan 60 is communicated with the multiple third air inlets 25 through the air duct in the furnace body 20. The third fan 60 is used to suck the air in the second chamber 21 out from the third air outlet 24 and then return it to the second chamber 21 from the third air inlet 25, so as to form an air flow flowing in the front-rear direction in the second chamber 21. In this way, the third air outlets 24 are arranged on the inner walls of the upper and lower sides of the furnace body 20 and close to the front side of the furnace body 20. Through this arrangement, it can be ensured that the air flow can flow in the upper and lower directions of the furnace body 20, thereby helping the air flow to cover each area of the furnace body 20, avoiding the air flow from concentrating on a certain part, further optimizing the uniformity of the temperature distribution. Moreover, the third air inlets 25 are distributed in an array on the rear side of the furnace body 20, which can promote the uniform entry of the air flow, avoid local overheating or cooling, and thus improve the air flow effect inside the furnace body 20; the reasonable layout of the third air inlets 25 and the third air outlets 24 enables the air flow to effectively cover the front, rear, upper and lower areas of the furnace body 20, avoiding the situation that the air flow concentrates on a certain part of the furnace body 20 or the temperature is uneven, thereby reducing the temperature difference in the furnace and improving the consistency of the nitriding treatment and the uniformity of the nitriding layer on the surface of the workpiece.

[0026] The third fan 60 includes a motor 62 and a wind wheel 63. The motor 62 is connected to the wind wheel 63 to drive the wind wheel 63 to rotate. The motor 62 is arranged outside the furnace shell 10, and the wind wheel 63 is arranged in the second circulation air duct in the furnace body 20. The second circulation air duct is communicated with the second chamber 21 through the third air outlet 24 and the third air inlet 25.

[0027] Refer to Figure 5 , the top of the furnace shell 10 is a top plate 12. The heating device 30 includes two groups of heating rods 31. The two groups of heating rods 31 both penetrate through the top plate 12 and extend into the first chamber 11. The two groups of heating rods 31 are respectively close to the outer walls of the left and right sides of the furnace body 20. Each group of heating rods 31 is arranged at intervals in the front-rear direction of the furnace body 20. Each heating rod 31 is parallel to the side wall of the furnace body 20, and each heating rod 31 is vertically arranged. In this way, when the heating rod 31 generates heat, it can evenly radiate the heat to the furnace body 20 through thermal radiation, so that the heat of the heating rod 31 can be transferred to the furnace body 20 through the convection of the air flow and also through thermal radiation, making the heating efficiency of the furnace body 20 relatively high.

[0028] The heating rods 31 are inserted into the furnace shell 10 from the outside of the furnace shell 10, so that the heating parts of the heating rods 31 extend into the first chamber 11. That is to say, the heating rods 31 penetrate through the top plate 12 and extend into the first chamber 11. In this way, the heating rods 31 are inserted on the top plate 12, which is convenient for later maintenance and replacement. There is no need to disassemble the furnace shell 10. As long as the heating rods 31 are pulled out from the top plate 12, the inspection and replacement of the heating rods 31 can be carried out, reducing the maintenance time and cost. Moreover, through the plug-in design of the heating rods 31, the heating parts can directly enter the first chamber 11, thereby heating the air and transferring heat to the furnace body 20. This design effectively improves the heating efficiency and avoids heat loss.

[0029] Such as Figure 12As described above, in another embodiment, a connecting plate 121 and a bracket 122 are provided on the top plate 12 of the furnace shell 10. The connecting plate 121 is connected to the tops of all the heating rods 31. An electric push rod 123 is provided on the bracket 122. The piston rod of the electric push rod 123 is vertically downward. The lower end of the piston rod of the electric push rod 123 is connected to the connecting plate 121. The electric push rod 123 is used to drive the connecting plate 121 to move up and down, and the connecting plate 121 can drive all the heating rods 31 to move up and down synchronously, so that the heating rods 31 are switched between the first state and the second state. When the heating rods 31 are in the first state, the heating rods 31 are inserted into the top plate 12, and the heating parts of the heating rods 31 extend into the first chamber 11. At this time, the holes on the top plate 12 for inserting the heating rods 31 are blocked by the heating rods. When the heating rods 31 are in the second state, the heating rods 31 are separated from the top plate 12, the heating rods 31 are located above the top plate 12, and the holes on the top plate 12 for inserting the heating rods 31 are opened, so that the first chamber 11 is communicated with the external atmosphere. A switching valve is provided at the air inlet end of the first fan 40. The switching valve can selectively connect the air inlet end of the first fan 40 to the first chamber 11 or the external atmosphere. In this way, when it is necessary to heat the first chamber 11, the heating rods 31 are in the first state, and the air inlet end of the first fan 40 is connected to the first chamber 11 through the switching valve. At this time, an air flow is generated in the first chamber 11 by the first fan 40 to transfer the heat of the heating rods 31 to the furnace body 20. When the nitriding treatment is completed, if it is necessary to quickly cool the furnace body 20, the heating rods 31 are in the second state, and the air inlet end of the first fan 40 is connected to the external atmosphere through the switching valve. At this time, cold air is introduced into the first chamber 11 by the first fan 40, and then the cold air flows out through the holes on the top plate 12 for inserting the heating rods 31, so as to quickly take away the heat. And at this time, all the heating rods 31 are moved out of the first chamber 11, which can avoid the residual temperature of the heating rods 31 from continuously heating the first chamber 11, so that the first chamber 11 can be cooled more quickly, so as to achieve the effect of rapid cooling. This process helps to avoid the metal surface deformation or dimensional change of the workpiece caused by the continuously high temperature. Moreover, the cold air flows out through the multiple holes on the top plate 12 for inserting the heating rods 31, which can ensure the uniform cooling inside the whole furnace body and avoid local overheating or uneven cooling, resulting in temperature differences.

[0030] This specification and the drawings are only exemplary descriptions of the present application, and are considered to have covered any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the present application and its equivalent technologies, the present application is intended to include these modifications and variations.

Claims

1. A nitriding furnace for improving the temperature uniformity in the furnace, characterized in that: include: Furnace shell (10); A furnace body (20) is arranged in a furnace shell (10); a first chamber (11) is arranged between an outer wall of the furnace body (20) and an inner wall of the furnace shell (10); a first air inlet (111) and a first air outlet (112) are arranged on the inner wall of the furnace shell (10); the furnace body (20) is made of a heat-conducting material; a second chamber (21) for placing a workpiece is arranged in the furnace body (20); a second air inlet (22), a second air outlet (23), a third air outlet (24) and a third air inlet (25) are arranged on the inner wall of the furnace body (20); A heating device (30) is arranged in the first chamber (11); A first fan (40) is arranged on the furnace shell (10) and is used to suck air in the first chamber (11) out from the first air outlet (112) and then return the air to the first chamber (11) from the first air inlet (111), so that the airflow continuously flows in the first chamber (11), and the airflow continuously transfers heat from the heating device (30) to the furnace body (20) when flowing; A second fan (50) is disposed on the furnace body (20) and is used to suck the air in the second chamber (21) out from the second air outlet (23) and then return the air to the second chamber (21) from the second air inlet (22), so as to form an airflow flowing in an up-and-down direction in the second chamber (21); The third fan (60) is arranged on the furnace body (20) and is used to suck the air in the second chamber (21) out from the third air outlet (24) and then return the air to the second chamber (21) from the third air inlet (25), so as to form an airflow flowing in the second chamber (21) in a front-to-rear direction.

2. The nitriding furnace according to claim 1, characterized in that: There are two first air inlets (111), the two first air inlets (111) are both located at the bottom of the furnace shell (10) and close to the front side of the furnace shell (10), the two first air inlets (111) are respectively located on the left and right sides of the furnace body (20), and the first air outlet (112) is located at the rear side of the furnace shell (10) and close to the top of the furnace shell (10).

3. The nitriding furnace according to claim 1, characterized in that: There are a plurality of second air inlets (22) which are divided into two groups. The two groups of second air inlets (22) are respectively located on the left and right inner walls of the furnace body (20) and close to the bottom of the furnace body (20). Each group of second air inlets (22) is arranged at intervals along the front-to-back direction of the furnace body (20). There are two second air outlets (23). The two second air outlets (23) are both located at the top of the furnace body (20) and arranged at intervals along the front-to-back direction of the furnace body (20). A second fan (50) is provided on each second air outlet (23).

4. The nitriding furnace according to claim 1, characterized in that: There are two third air outlets (24), which are respectively located on the upper and lower inner walls of the furnace body (20) and close to the front side of the furnace body (20), and there are multiple third air inlets (25) which are distributed in an array on the rear side of the furnace body (20).

5. The nitriding furnace according to claim 1, characterized in that: The heating device (30) comprises two groups of heating rods (31), the two groups of heating rods (31) being respectively close to the left and right outer walls of the furnace body (20), and each group of heating rods (31) being arranged at intervals along the front-rear direction of the furnace body (20).

6. The nitriding furnace according to claim 5, characterized in that: The heating rods (31) are plugged into the furnace shell (10) from the outside of the furnace shell (10), so that the heating portion of the heating rods (31) extends into the first chamber (11).

7. The nitriding furnace according to claim 6, characterized in that: A connecting plate (121) and a bracket (122) are provided on the top of the furnace shell (10); the connecting plate (121) is connected to the tops of all the heating rods (31); a driving device is provided on the bracket (122); the driving device is used to drive the connecting plate (121) to move up and down, so as to drive all the heating rods (31) to move synchronously, thereby switching the heating rods (31) between a first state and a second state; when the heating rod (31) is in the first state, the heating rod (31) is plugged into the furnace shell (10), and the heating portion of the heating rod (31) extends into the first chamber (11); when the heating rod (31) is in the second state, the heating rod (31) is detached from the furnace shell (10), and the hole on the furnace shell (10) for plugging the heating rod (31) is opened, so that the first chamber (11) is connected to the external atmosphere; The air inlet end of the first fan (40) is provided with a switching valve, and the switching valve can enable the air inlet end of the first fan (40) to be connected to the first chamber (11) or the external atmosphere.

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