roller hearth kiln

Abstract

The present invention discloses a roller hearth kiln, which includes a furnace body having a hearth. A conveying device and a heating device are installed in the hearth, and a temperature-adjusting air inlet device is provided in the hearth, where the air outlet speed at the middle position of the hearth is greater than the air outlet speed at the two side positions of the hearth. This roller hearth kiln can regulate the temperature uniformity in the width direction of the hearth, and has the advantages of simple regulation, good regulation effect, simple structure, low cost, easy transformation and implementation, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of heat treatment furnace equipment, and particularly relates to a roller hearth kiln. Background Art

[0002] For an electrically heated roller hearth kiln, heating elements pass through the furnace chamber horizontally from above and below. The materials and the roller rods for placing the materials are located between the upper and lower heating elements. From the perspective of the temperature difference in the cross-section of the furnace chamber, the temperature difference between the upper and lower parts can be adjusted by regulating the power of the upper and lower heating elements. However, since the heating elements pass through the furnace chamber horizontally, there is no very effective control means for the temperature difference in the width direction. Therefore, it is a shortcoming in the temperature field control of existing roller hearth kilns that the temperature uniformity in the width direction is difficult to effectively adjust.

[0003] Since the heat on both sides of the furnace chamber will diffuse to the outside, the temperature distribution in the cross-section of the furnace chamber will show a characteristic of being high in the middle and low on both sides in the width direction of the furnace chamber, resulting in a temperature difference in the width direction of the furnace chamber. When the size of the roller hearth kiln furnace chamber is small, the temperature difference in the width direction of the furnace chamber is not very obvious. However, as the width of the kiln furnace increases, the temperature difference in the width direction of the furnace chamber will also increase, thus seriously affecting the quality of heat treatment products. In order to reduce the temperature difference in the width direction of the furnace chamber, the existing method is usually to add side heat insulation structures on both sides of the roller hearth kiln to reduce the radiation heat dissipation on both sides, thereby alleviating the temperature difference in the width direction of the furnace chamber. However, this method has little effect and is difficult to meet the heat treatment requirements of materials with high temperature sensitivity such as battery materials, resulting in poor sintering consistency of products and low yield. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a roller hearth kiln that can regulate the temperature uniformity in the width direction of the furnace chamber, is simple to regulate, has good regulation effect, simple structure, low cost, and is easy to transform and implement.

[0005] To solve the above technical problem, the present invention adopts the following technical solutions:

[0006] A roller hearth kiln includes a furnace body having a furnace chamber, a conveying device and a heating device are installed in the furnace chamber, and a temperature regulating air inlet device is provided in the furnace chamber, where the air outlet speed at the middle position of the furnace chamber is greater than the air outlet speed at the two side positions of the furnace chamber.

[0007] As a further improvement of the above technical solution:

[0008] The temperature-regulating air inlet device includes at least one temperature-regulating air inlet pipe penetrating through the furnace along the furnace width direction. One or more middle air outlets are provided on the temperature-regulating air inlet pipe at the middle position of the furnace, and one or more side air outlets are provided on the temperature-regulating air inlet pipe at both side positions of the furnace. The sum of the opening areas of all the middle air outlets is greater than the sum of the opening areas of all the side air outlets at any side position of the furnace. The temperature-regulating air inlet device further includes a temperature-regulating air supply assembly for introducing temperature-regulating gas into the temperature-regulating air inlet pipe.

[0009] The temperature-regulating air inlet device has multiple temperature-regulating air inlet pipes, and the multiple temperature-regulating air inlet pipes are arranged at intervals in sequence along the conveying direction of the conveying device.

[0010] The heating device includes one or more upper heating elements located above the conveying device. All the temperature-regulating air inlet pipes are located below the upper heating elements and above the conveying device. The opening directions of the middle air outlets and the side air outlets of all the temperature-regulating air inlet pipes are downward.

[0011] Side air inlet devices are provided on both side furnace walls of the roller hearth kiln. The side air inlet device includes one or more side air inlet pipelines penetrating through the furnace wall of the furnace body and communicating with the furnace chamber, and a side air supply assembly for introducing gas into the side air inlet pipelines.

[0012] The temperature-regulating air supply assembly and the side air supply assembly are the same air supply assembly. The air supply assembly includes an air inlet main pipe and an air source. The air inlet main pipe penetrates through the furnace chamber. One end of the air inlet main pipe is connected to the air source, and both ends of each temperature-regulating air inlet pipe are connected to the other end of the air inlet main pipe through a gas guiding pipeline. Each side air inlet pipeline is connected to the other end of the air inlet main pipe through a gas guiding pipeline.

[0013] Each temperature-regulating air inlet pipe and each side air inlet pipeline are provided with an independent adjustable flowmeter.

[0014] The side air inlet device has multiple side air inlet pipelines, and the multiple side air inlet pipelines are arranged at intervals in sequence along the conveying direction of the conveying device; the communication ports of each side air inlet pipeline with the furnace chamber face the materials on the conveying device.

[0015] The roller hearth kiln is further provided with a bottom air inlet device. The bottom air inlet device includes one or more bottom air inlet pipelines penetrating through the bottom wall of the furnace body and communicating with the furnace chamber, and a bottom air supply assembly for introducing gas into the bottom air inlet pipelines.

[0016] The heating device has a lower heating element located below the conveying device. A gas baffle is provided in the furnace chamber below the lower heating element. The gas baffle is located above the communication port of the bottom gas inlet pipeline with the furnace chamber, and enables the gas introduced into the furnace chamber through each bottom gas inlet pipeline to flow along the bottom surface of the gas baffle towards the periphery of the gas baffle and enter the furnace chamber above the gas baffle.

[0017] Compared with the prior art, the advantages of the present invention are as follows:

[0018] The roller hearth kiln of the present invention is provided with a temperature-adjusting air inlet device in the furnace chamber. The air outlet speed of the temperature-adjusting air inlet device at the middle position of the furnace chamber is greater than that at the two side positions of the furnace chamber. When introducing temperature-adjusting gas with a temperature lower than the gas temperature in the furnace chamber into the furnace chamber through the temperature-adjusting air inlet device, the air inlet speed at the middle position of the furnace chamber is relatively fast, and the air inlet speed at the two side positions of the furnace chamber is relatively slow, so that the temperature reduction speed at the middle position of the furnace chamber is faster than that at the two side positions of the furnace chamber, thereby improving the temperature difference in the width direction of the furnace chamber, making the temperature uniformity in the width direction of the furnace chamber better, and improving the quality of heat-treated products. The roller hearth kiln only needs to be provided with a temperature-adjusting air inlet device with different air outlet speeds at different positions to realize the regulation of the temperature difference in the width direction of the furnace chamber. It has the advantages of simple regulation, good regulation effect, simple structure, low cost, easy implementation, and easy transformation of existing equipment. Brief Description of the Drawings

[0019] Figure 1 It is a schematic cross-sectional structure diagram of the roller hearth kiln (without the temperature-adjusting air supply assembly).

[0020] Figure 2 It is a schematic cross-sectional structure diagram of the roller hearth kiln (with the temperature-adjusting air supply assembly).

[0021] Figure 3 It is a schematic structure diagram of the temperature-adjusting air inlet pipe.

[0022] Legend Explanation:

[0023] 1. Furnace body; 11. Furnace chamber; 2. Conveying device; 3. Heating device; 31. Upper heating element; 32. Lower heating element; 4. Temperature-adjusting air inlet pipe; 41. Middle air outlet; 42. Side air outlet; 5. Side air inlet pipeline; 6. Air inlet main pipe; 7. Bottom air inlet pipeline. Detailed Description of the Invention

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Such as Figure 1 And Figure 2As shown in the figure, the roller hearth kiln of this embodiment includes a furnace body 1 with a hearth 11. A conveying device 2 and a heating device 3 are installed in the hearth 11. A temperature-regulating air inlet device is provided in the hearth 11, where the air outlet speed at the middle position of the hearth 11 is greater than that at the two side positions of the hearth 11. Herein, the middle position of the hearth 11 refers to the middle position in the width direction of the cross-section of the hearth 11, and the two side positions of the hearth 11 refer to the two side positions close to the two side walls of the hearth 11 in the width direction of the cross-section of the hearth 11. A temperature-regulating air inlet device is arranged in the hearth 11 of the roller hearth kiln, and the air outlet speed of the temperature-regulating air inlet device at the middle position of the hearth 11 is greater than that at the two side positions of the hearth 11. When introducing temperature-regulating gas with a temperature lower than the gas temperature in the hearth 11 into the hearth 11 through the temperature-regulating air inlet device, the air inlet speed at the middle position of the hearth 11 is relatively fast, and the air inlet speed at the two side positions of the hearth 11 is relatively slow, so that the temperature reduction speed at the middle position of the hearth 11 is faster than that at the two side positions of the hearth 11, thereby improving the temperature difference in the width direction of the hearth 11, making the temperature uniformity in the width direction of the hearth 11 better, and improving the quality of heat-treated products. The roller hearth kiln only needs to be provided with a temperature-regulating air inlet device with different air outlet speeds at different positions to realize the regulation of the temperature difference in the width direction of the hearth 11. It has the advantages of simple regulation, good regulation effect, simple structure, low cost, easy implementation, and easy transformation of existing equipment.

[0026] In this embodiment, the temperature-regulating air inlet device includes at least one temperature-regulating air inlet pipe 4 penetrating through the hearth 11 along the width direction of the hearth 11. One or more middle air outlet openings 41 are provided at the middle position of the hearth 11 on the temperature-regulating air inlet pipe 4, and one or more side air outlet openings 42 are provided at the two side positions of the hearth 11 on the temperature-regulating air inlet pipe 4. The total opening area of all the middle air outlet openings 41 is greater than the total opening area of all the side air outlet openings 42 at any side position of the hearth 11. The temperature-regulating air inlet device further includes a temperature-regulating air supply assembly for introducing temperature-regulating gas into the temperature-regulating air inlet pipe 4. Since the total opening area of all the middle air outlet openings 41 is greater than the total opening area of all the side air outlet openings 42 at any side position of the hearth 11, when the temperature-regulating air supply assembly introduces temperature-regulating gas into the temperature-regulating air inlet pipe 4, the air outlet speed of the temperature-regulating air inlet pipe 4 corresponding to the middle position of the hearth 11 is large, while the air outlet speed corresponding to the side position of the hearth 11 is small. The temperature-regulating air inlet device only adopts the combination of the temperature-regulating air inlet pipe 4 and the temperature-regulating air supply assembly, and has the advantages of simple and compact structure, low cost, and easy manufacturing and assembly.

[0027] The total opening area of the above-mentioned middle air outlet openings 41 is controlled by configuring the number of the middle air outlet openings 41 and the opening area of each middle air outlet opening 41, and the total opening area of the side air outlet openings 42 at each side position is controlled by configuring the number of the side air outlet openings 42 and the opening area of each side air outlet opening 42. This embodiment is controlled by controlling the opening area, such asFigure 3 As shown, the middle air outlet 41 and the side air outlet 42 are both strip-shaped holes arranged along the extending direction of the temperature-adjusting intake pipe 4. The middle air outlet 41 and the side air outlet 42 have the same width, and the length of the middle air outlet 41 is greater than that of the side air outlet 42, so that the opening area of the middle air outlet 41 is greater than that of the side air outlet 42.

[0028] In this embodiment, the temperature-adjusting intake device has a plurality of temperature-adjusting intake pipes 4, and the plurality of temperature-adjusting intake pipes 4 are arranged at intervals in sequence along the conveying direction of the conveying device 2. In this way, the temperature difference can be regulated in a section of the furnace chamber 11 along the conveying direction of the conveying device 2, the overall temperature difference of this section of the furnace chamber 11 can be improved, and the overall temperature uniformity of this section of the furnace chamber 11 is good.

[0029] In this embodiment, the heating device 3 includes more than one upper heating element 31 located above the conveying device 2. All the temperature-adjusting intake pipes 4 are located below the upper heating element 31 and above the conveying device 2, and the openings of the middle air outlets 41 and the side air outlets 42 of all the temperature-adjusting intake pipes 4 face downward. The gas entering the furnace chamber 11 through the temperature-adjusting intake pipe 4 is not heated by the upper heating element 31, which is beneficial to quickly and efficiently improving the temperature difference. At the same time, the gas entering the furnace chamber 11 through the temperature-adjusting intake pipe 4 directly blows onto the materials on the conveying device 2, which is beneficial to the full contact between the process atmosphere and the materials.

[0030] In this embodiment, side air intake devices are provided on both side furnace walls of the roller hearth kiln. The side air intake device includes more than one side air intake pipeline 5 penetrating through the furnace wall of the furnace body 1 and communicating with the furnace chamber 11 and a side air supply assembly for introducing gas into the side air intake pipeline 5. The side air supply assembly passes the gas into the two side positions of the furnace chamber 11 through the side air intake pipeline 5, which can reduce the temperature at the two side positions of the furnace chamber 11. When the temperature-adjusting intake device adjusts the temperature difference, it is possible to over-adjust so that the temperature at the two side positions of the furnace chamber 11 is higher than the temperature at the middle of the furnace chamber 11. At this time, the temperature at the two side positions of the furnace chamber 11 can be reduced by adjusting the gas velocity introduced into the two side positions of the furnace chamber 11 by the side air supply assembly, so that the temperature in the furnace chamber 11 is uniform, solving the problem of over-adjustment of the temperature-adjusting intake device, improving the flexibility of temperature adjustment and reducing the difficulty of temperature adjustment. At the same time, the side air intake pipeline 5 penetrates through the furnace wall of the furnace body 1, and the gas in the side air intake pipeline 5 can be preheated, which is beneficial to saving energy consumption.

[0031] In this embodiment, the temperature-adjusting air supply assembly and the side air supply assembly are the same air supply assembly, which can improve the structural simplicity and compactness, reduce costs, and reduce the control difficulty. The air supply assembly includes an intake main pipe 6 and a gas source. The intake main pipe 6 penetrates through the furnace chamber 11. One end of the intake main pipe 6 is connected to the gas source, and both ends of each temperature-adjusting intake pipe 4 are connected to the other end of the intake main pipe 6 through a conduit, and each side intake pipe 5 is connected to the other end of the intake main pipe 6 through a conduit. Using one set of air supply assemblies for air supply can improve the structural simplicity and compactness and reduce costs. Moreover, since the intake main pipe 6 penetrates through the furnace chamber 11, the high-temperature gas in the furnace chamber 11 can be used to preheat the gas in the intake main pipe 6, achieving the purpose of saving energy consumption.

[0032] In this embodiment, each temperature-adjusting intake pipe 4 and each side intake pipe 5 are provided with an independent adjustable flowmeter. The adjustable flowmeter controls the gas flow rate of the temperature-adjusting intake pipe 4 and each side intake pipe 5, realizing precise and independent adjustment of the ventilation speed of the temperature-adjusting intake pipe 4 and each side intake pipe 5, which is convenient for flexible and precise control of the temperature in the furnace chamber 11.

[0033] In this embodiment, the side air intake device has multiple side intake pipes 5, and the multiple side intake pipes 5 are arranged at intervals in sequence along the conveying direction of the conveying device 2, realizing differential temperature control of a section of the furnace chamber 11 in the conveying direction of the conveying device 2; the communication ports of each side intake pipe 5 with the furnace chamber 11 face the materials on the conveying device 2, which is conducive to the full contact between the process atmosphere and the materials.

[0034] In this embodiment, the roller hearth kiln is also provided with a bottom air intake device. The bottom air intake device includes one or more bottom intake pipes 7 penetrating through the bottom wall of the furnace body 1 and communicating with the furnace chamber 11 and a bottom air supply assembly for introducing gas into the bottom intake pipes 7. The bottom air supply assembly includes a gas source, and each bottom intake pipe 7 is connected to the gas source through a pipeline. The bottom air supply assembly introduces the process gas into the furnace chamber 11 from the bottom of the furnace chamber 11 through the bottom intake pipes 7. As the main air intake mode of the kiln, it is used to keep the atmosphere content in the furnace up to the process requirements. The bottom intake pipes 7 of this bottom air intake device penetrate through the bottom wall of the furnace body 1, playing a role in preheating the gas in the bottom intake pipes 7, which is beneficial to saving energy consumption and improving temperature uniformity. Preferably, each bottom intake pipe 7 in this embodiment is provided with an independent adjustable flowmeter to precisely control the gas velocity of the bottom intake pipes 7 and thus precisely control the gas velocity entering the bottom of the furnace chamber 11.

[0035] In this embodiment, the heating device 3 has a lower heating element 32 located below the conveying device 2. A gas baffle (not shown in the figure) is provided in the furnace chamber 11 below the lower heating element 32. The gas baffle is located above the communication port between the bottom air inlet pipeline 7 and the furnace chamber 11, and enables the gas introduced into the furnace chamber 11 through each bottom air inlet pipeline 7 to flow along the bottom surface of the gas baffle towards the periphery of the gas baffle and then enter the furnace chamber 11 above the gas baffle. The gas baffle enables the gas to flow along the bottom surface of the gas baffle towards the periphery of the gas baffle and then enter the furnace chamber 11 above the gas baffle, which is conducive to the gas being fully heated in the lower region of the furnace chamber 11, avoiding the lower-temperature gas from directly blowing onto the material, and also conducive to improving the uniformity of the atmosphere in the furnace chamber 11. At the same time, a large amount of gas enters the furnace chamber 11 from the bottom, and the lower heating element with independently adjustable calorific value heats it, taking advantage of the temperature control characteristics of the roller kiln, reducing the difficulty of controlling the temperature uniformity, and being conducive to the stability of the temperature uniformity in the furnace.

[0036] When the roller kiln of this embodiment is actually working, as long as the temperature-adjusting air inlet device and the side air inlet device play a role in regulating the temperature field and the atmosphere field, the air inlet speed of the temperature-adjusting air inlet device and the side air inlet device is much smaller than the air inlet speed of the bottom air inlet device.

[0037] In this embodiment, the upper heating element 31 and the lower heating element 32 adopt the prior art and are heating rods arranged through the furnace chamber 11. The conveying device 2 is the prior art, and it includes a plurality of conveying roller rods arranged at intervals in sequence and a driving mechanism for driving the conveying roller rods to rotate to convey materials.

[0038] The above is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art of this technology, the improvements and transformations obtained without departing from the technical concept of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A roller hearth kiln, comprising a furnace body (1) having a hearth (11), wherein a conveying device (2) and a heating device (3) are installed in the hearth (11), and characterized in that: A temperature-adjusting air inlet device with an air outlet speed greater at the middle position of the furnace chamber (11) than at the two side positions of the furnace chamber (11) is provided in the furnace chamber (11). The temperature-adjusting air inlet device includes at least one temperature-adjusting air inlet pipe (4) arranged through the furnace chamber (11) along the width direction of the furnace chamber (11). One or more middle air outlet openings (41) are provided at the middle position of the furnace chamber (11) on the temperature-adjusting air inlet pipe (4), and one or more side air outlet openings (42) are provided at the two side positions of the furnace chamber (11) on the temperature-adjusting air inlet pipe (4). The total opening area of all the middle air outlet openings (41) is greater than the total opening area of all the side air outlet openings (42) at any side position of the furnace chamber (11). The temperature-adjusting air inlet device further includes a temperature-adjusting air supply assembly for introducing temperature-adjusting gas into the temperature-adjusting air inlet pipe (4). The temperature-adjusting air inlet device has multiple temperature-adjusting air inlet pipes (4), and the multiple temperature-adjusting air inlet pipes (4) are arranged at intervals in sequence along the conveying direction of the conveying device (2). The heating device (3) includes one or more upper heating elements (31) located above the conveying device (2). All the temperature-adjusting air inlet pipes (4) are located below the upper heating elements (31) and above the conveying device (2), and the middle air outlet openings (41) and side air outlet openings (42) of all the temperature-adjusting air inlet pipes (4) are arranged with their openings facing downwards.

2. The roller hearth kiln according to claim 1, characterized in that: Side air inlet devices are provided on the two side furnace walls of the roller hearth kiln. The side air inlet device includes more than one side air inlet pipeline (5) penetrating through the furnace wall of the furnace body (1) and communicating with the furnace chamber (11), and a side air supply assembly for introducing gas into the side air inlet pipeline (5).

3. The roller hearth kiln according to claim 2, characterized in that: The temperature-adjusting air supply assembly and the side air supply assembly are the same air supply assembly. The air supply assembly includes an air inlet main pipe (6) and an air source. The air inlet main pipe (6) is arranged through the furnace chamber (11). One end of the air inlet main pipe (6) is connected to the air source, and both ends of each temperature-adjusting air inlet pipe (4) are connected to the other end of the air inlet main pipe (6) through a guiding pipeline. Each side air inlet pipeline (5) is connected to the other end of the air inlet main pipe (6) through a guiding pipeline.

4. The roller hearth kiln according to claim 3, characterized in that: Each temperature-adjusting air inlet pipe (4) and each side air inlet pipeline (5) are provided with an independent adjustable flowmeter.

5. The roller hearth kiln according to claim 2, characterized in that: The side air inlet device has multiple side air inlet pipelines (5), and the multiple side air inlet pipelines (5) are arranged at intervals in sequence along the conveying direction of the conveying device (2). The communication ports of each side air inlet pipeline (5) with the furnace chamber (11) face the materials on the conveying device (2).

6. The roller hearth kiln according to any one of claims 1 to 5, characterized in that: The roller hearth kiln is further provided with a bottom air inlet device. The bottom air inlet device includes more than one bottom air inlet pipeline (7) penetrating through the bottom wall of the furnace body (1) and communicating with the furnace chamber (11), and a bottom air supply assembly for introducing gas into the bottom air inlet pipeline (7).

7. The roller hearth kiln according to claim 6, characterized in that: The heating device (3) has a lower heating element (32) located below the conveying device (2). A gas baffle is provided in the furnace chamber (11) below the lower heating element (32). The gas baffle is located above the communication port of the bottom air inlet pipeline (7) and the furnace chamber (11), and enables the gas introduced into the furnace chamber (11) from each bottom air inlet pipeline (7) to flow along the bottom surface of the gas baffle to the periphery of the gas baffle and then enter the furnace chamber (11) above the gas baffle.

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