A roller hearth kiln

Abstract

The present invention discloses a roller hearth kiln, which comprises a furnace body having a hearth. A conveying device and a heating device are installed in the hearth. One or more middle inlet pipes for introducing temperature-regulating gas into the middle position of the hearth are installed on the furnace body. One or more side inlet pipes for introducing temperature-regulating gas into the side positions of the hearth are provided at the positions corresponding to the two side parts of the hearth on the furnace body. The roller hearth kiln further comprises a temperature-regulating air supply assembly for introducing temperature-regulating gas into each middle inlet pipe and each side inlet pipe, and enabling the total air intake speed of all the middle inlet pipes to be greater than the total air intake speed of all the side inlet pipes at each side position of the hearth. This kind of 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 manufacturing and assembly, 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, the heating elements pass horizontally through the furnace chamber from above and below, and 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 adjusting the power of the upper and lower heating elements. However, since the heating elements pass horizontally through the furnace chamber, there is no very effective control means for the temperature difference in the width direction. Therefore, it is a drawback in the temperature field control of the existing roller hearth kiln 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 the characteristics 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 increases, the temperature difference in the width direction of the furnace chamber will also increase, thus seriously affecting the quality of heat-treated products. In order to reduce the temperature difference in the width direction of the furnace chamber, the existing method is usually to increase the side insulation structure 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 existing technology 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, is easy to manufacture and assemble, and is easy to retrofit 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, one or more middle inlet pipes for introducing temperature-regulating gas into the middle position of the furnace chamber are installed on the furnace body, one or more side inlet pipes for introducing temperature-regulating gas into the side positions of the furnace chamber are provided at the corresponding two side positions of the furnace chamber, and the roller hearth kiln further includes a temperature-regulating gas supply assembly for introducing temperature-regulating gas into each middle inlet pipe and each side inlet pipe, and the total intake speed of all middle inlet pipes is greater than the total intake speed of all side inlet pipes at each side position of the furnace chamber.

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

[0008] The temperature-adjusting air supply assembly includes an air source. All the middle air inlet pipes are connected to the air source through a first main air inlet pipe. A first adjustable flowmeter for adjusting the gas flow rate is provided on the first main air inlet pipe. All the side air inlet pipes at each side position of the furnace chamber are connected to the air source through a second main air inlet pipe. A second adjustable flowmeter for adjusting the gas flow rate is provided on the second main air inlet pipe.

[0009] The temperature-adjusting air supply assembly includes an air source. Each middle air inlet pipe and each side air inlet pipe are connected to the air source. A third adjustable flowmeter for adjusting the gas flow rate is provided on each middle air inlet pipe and each side air inlet pipe.

[0010] Among the multiple middle air inlet pipes, the air outlet of at least one middle air inlet pipe is at a different height position from the air outlets of other middle air inlet pipes. Among the multiple side air inlet pipes in each group of side temperature-adjusting air inlet pipe groups, the air outlet of at least one side air inlet pipe is at a different height position from the air outlets of other side air inlet pipes.

[0011] A plurality of middle air inlet pipes are installed on the furnace body. The plurality of middle air inlet pipes are divided into multiple groups of middle pipe groups arranged at intervals in the conveying direction of the conveying device. Each group of middle pipe groups includes more than one middle air inlet pipe. At each side position of the furnace chamber corresponding to the furnace body, a plurality of side air inlet pipes are installed. The plurality of side air inlet pipes are divided into multiple groups of side pipe groups arranged at intervals in the conveying direction of the conveying device. Each group of side pipe groups includes more than one side air inlet pipe.

[0012] Side air inlet devices are provided on both side furnace walls of the roller hearth kiln. The side air inlet device includes more than one side wall air inlet pipeline 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 wall air inlet pipeline.

[0013] The temperature-adjusting air supply assembly and the side air supply assembly are the same air supply assembly. The air supply assembly includes a preheating main air inlet pipe and an air source. The preheating main air inlet pipe penetrates through the furnace chamber. One end of the preheating main air inlet pipe is connected to the air source. Each middle air inlet pipe, side air inlet pipe, and side wall air inlet pipeline are connected to the other end of the preheating main air inlet pipe. A fourth adjustable flowmeter for adjusting the gas flow rate is provided on each side wall air inlet pipeline.

[0014] The side air inlet device has a plurality of side wall air inlet pipelines, and the plurality of side wall air inlet pipelines are arranged at intervals in the conveying direction of the conveying device. The communication ports of each side wall 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 more than one bottom air inlet pipeline 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 pipeline.

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

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

[0018] In the roller hearth kiln of the present invention, by providing a middle air inlet pipe for introducing temperature-regulating gas into the middle position of the furnace chamber and a side air inlet pipe for introducing temperature-regulating gas into the side position of the furnace chamber, and when the temperature-regulating gas supply assembly introduces temperature-regulating gas into each middle air inlet pipe and each side air inlet pipe, the total intake air speed of all the middle air inlet pipes is greater than the total intake air speed of all the side air inlet pipes at each side position of the furnace chamber, that is, the intake air speed at the middle position of the furnace chamber is relatively fast, and the intake air speed at the two side positions of the furnace chamber is relatively slow, so that the cooling speed at the middle position of the furnace chamber is faster than the cooling speed 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. This roller hearth kiln only needs to be provided with a middle air inlet pipe, a side air inlet pipe and a temperature-regulating gas supply assembly 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 and compact structure, low cost, easy manufacturing and assembly, 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.

[0020] Legend Explanation:

[0021] 1. Furnace body; 11. Furnace chamber; 2. Conveying device; 3. Heating device; 31. Lower heating element; 32. Upper heating element; 4. Middle air inlet pipe; 5. Side air inlet pipe; 6. Side wall air inlet pipeline; 7. Preheating air inlet main pipe; 8. Bottom air inlet pipeline. Detailed Embodiments

[0022] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0023] Such as Figure 1As 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. One or more middle inlet pipes 4 for introducing temperature-regulating gas into the middle position of the hearth 11 are installed on the furnace body 1. One or more side inlet pipes 5 for introducing temperature-regulating gas into the side positions of the hearth 11 are provided at the two side positions of the hearth 11 corresponding to the furnace body 1. The roller hearth kiln further includes a temperature-regulating air supply assembly for introducing temperature-regulating gas into each middle inlet pipe 4 and each side inlet pipe 5, and making the total intake air speed of all the middle inlet pipes 4 greater than the total intake air speed of all the side inlet pipes 5 at each side position of the hearth 11. Among them, the middle position of the hearth 11 refers to the middle position in the cross-sectional width direction 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 cross-sectional width direction of the hearth 11.

[0024] By providing the middle inlet pipes 4 for introducing temperature-regulating gas into the middle position of the hearth 11 and the side inlet pipes 5 for introducing temperature-regulating gas into the side positions of the hearth 11, and when the temperature-regulating air supply assembly introduces temperature-regulating gas into each middle inlet pipe 4 and each side inlet pipe 5, making the total intake air speed of all the middle inlet pipes 4 greater than the total intake air speed of all the side inlet pipes 5 at each side position of the hearth 11, that is, making the intake air speed at the middle position of the hearth 11 relatively fast and the intake air speed at the two side positions of the hearth 11 relatively slow, the temperature drop speed at the middle position of the hearth 11 is faster than the temperature drop speed at the two side positions of the hearth 11. Thus, the temperature difference in the width direction of the hearth 11 can be improved, the temperature uniformity in the width direction of the hearth 11 is better, and the quality of heat-treated products can be improved. The roller hearth kiln only needs to be provided with the middle inlet pipes 4, the side inlet pipes 5 and the temperature-regulating air supply assembly 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 and compact structure, low cost, easy to manufacture and assemble, easy to implement, and easy to transform existing equipment.

[0025] In this embodiment, the temperature-regulating air supply assembly includes a gas source. All the middle inlet pipes 4 are connected to the gas source through a first intake main pipe. A first adjustable flowmeter for adjusting the gas flow rate is provided on the first intake main pipe. All the side inlet pipes 5 at each side position of the hearth 11 are connected to the gas source through a second intake main pipe. A second adjustable flowmeter for adjusting the gas flow rate is provided on the second intake main pipe. The gas flow rate of the first intake main pipe can be regulated through each first adjustable flowmeter, and then the total intake air speed of all the middle inlet pipes 4 can be regulated. The gas flow rate of the second intake main pipe can be regulated through the second adjustable flowmeter, and then the total intake air speed of all the side inlet pipes 5 at each side position of the hearth 11 can be regulated, which is convenient for flexible and accurate regulation of the temperature in the hearth 11. The structure of this temperature-regulating air supply assembly is simple, the cost is low, and the regulation is simple.

[0026] In other embodiments, other forms can also be adopted. For example, the temperature-adjusting air supply assembly includes an air source, each middle intake pipe 4 and each side intake pipe 5 are connected to the air source, and each middle intake pipe 4 and each side intake pipe 5 are provided with a third adjustable flowmeter for adjusting the gas flow rate. In this way, the ventilation speeds of each middle intake pipe 4 and each side intake pipe 5 can be independently adjusted. On the premise of being able to adjust the total intake speed, the same speed of each middle intake pipe 4 and each side intake pipe 5 can also be adjusted, that is, the intake speed at each position in the furnace chamber 11 is adjusted, further improving the flexibility of regulation and control.

[0027] In this embodiment, the air outlet of at least one middle intake pipe 4 among the multiple middle intake pipes 4 is located at a different height position from the air outlets of other middle intake pipes 4, and the air outlet of at least one side intake pipe 5 among the multiple side intake pipes 5 of each group of side temperature-adjusting intake pipe groups is located at a different height position from the air outlets of other side intake pipes 5. The air outlets of the middle intake pipes 4 and the air outlets of the side intake pipes 5 are located at different height positions, so that the intake air is at different height positions in the furnace chamber 11, and the temperature in the width direction can be regulated at different height positions in the furnace chamber 11, which is beneficial to improving the overall temperature uniformity in the furnace chamber 11.

[0028] In this embodiment, multiple middle intake pipes 4 are installed on the furnace body 1, and the multiple middle intake pipes 4 are divided into multiple groups of middle pipe groups arranged at intervals in the conveying direction of the conveying device 2, and each group of middle pipe groups includes more than one middle intake pipe 4; multiple side intake pipes 5 are installed at each side position of the furnace chamber 11 corresponding to the furnace body 1, and the multiple side intake pipes 5 are divided into multiple groups of side pipe groups arranged at intervals in the conveying direction of the conveying device 2, and each group of side pipe groups includes more than one side intake pipe 5. In this way, the temperature difference can be regulated in a section of the furnace chamber 11 in the conveying direction of the conveying device 2, the overall temperature difference in this section of the furnace chamber 11 can be improved, and the overall temperature uniformity in this section of the furnace chamber 11 is good.

[0029] 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 wall air intake pipeline 6 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 wall air intake pipeline 6. The side air supply assembly introduces gas into the two side positions of the furnace chamber 11 through the side wall air intake pipeline 6, which can reduce the temperature at the two side positions of the furnace chamber 11. When adjusting 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 in the middle of the furnace chamber 11. At this time, the temperature of the gas introduced into the two side positions of the furnace chamber 11 by the side air supply assembly can be adjusted to reduce the temperature at the two side positions of the furnace chamber 11, making the temperature in the furnace chamber 11 uniform, solving the problem of over-adjustment of the temperature-adjusting air intake device, improving the flexibility of temperature adjustment and reducing the difficulty of temperature adjustment. At the same time, the side wall air intake pipeline 6 penetrates through the furnace wall of the furnace body 1, and the gas in the side wall air intake pipeline 6 can be preheated, which is beneficial to saving energy consumption.

[0030] In this embodiment, the temperature-adjusting air supply assembly and the side air supply assembly are the same air supply assembly. The air supply assembly includes a preheating intake main pipe 7 and a gas source. The preheating intake main pipe 7 penetrates through the furnace chamber 11. One end of the preheating intake main pipe 7 is connected to the gas source, and each middle intake pipe 4, side intake pipe 5, and side wall intake pipeline 6 are connected to the other end of the preheating intake main pipe 7; each side wall intake pipeline 6 is provided with a fourth adjustable flowmeter for adjusting the gas flow rate. Using a set of air supply assemblies for air supply can improve the structural simplicity and compactness and reduce costs. Moreover, since the preheating intake main pipe 7 penetrates through the furnace chamber 11, the high-temperature gas in the furnace chamber 11 can be used to preheat the gas in the preheating intake main pipe 7, achieving the purpose of energy conservation.

[0031] In this embodiment, the side intake device has multiple side wall intake pipelines 6. The multiple side wall intake pipelines 6 are arranged at intervals in sequence along the conveying direction of the conveying device 2, so as to realize the temperature difference control of a section of the furnace chamber 11 in the conveying direction of the conveying device 2; the communication ports of each side wall intake pipeline 6 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.

[0032] In this embodiment, the roller kiln is further provided with a bottom intake device. The bottom intake device includes one or more bottom intake pipelines 8 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 pipelines 8. The bottom air supply assembly includes a gas source, and each bottom intake pipeline 8 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 pipelines 8. As the main air intake method of the kiln, it is used to keep the atmosphere content in the furnace reaching the process requirements. The bottom intake pipelines 8 of this bottom intake device penetrate through the bottom wall of the furnace body 1, which plays a role in preheating the gas in the bottom intake pipelines 8, being beneficial to energy conservation and improving temperature uniformity. Preferably, each bottom intake pipeline 8 in this embodiment is provided with an independent adjustable flowmeter to accurately control the gas velocity of the gas entering the bottom of the furnace chamber 11 according to the gas flow rate of the bottom intake pipelines 8.

[0033] In this embodiment, the heating device 3 has a lower heating element 31 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 31. The gas baffle is located above the communication port between the bottom air inlet pipeline 8 and the furnace chamber 11, and enables the gas introduced into the furnace chamber 11 through each bottom air inlet pipeline 8 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 towards 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, making use 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.

[0034] During the actual operation of the roller kiln in this embodiment, the intake of the middle air inlet pipe 4, the side air inlet pipe 5, and the side air intake device only plays a role in regulating the temperature field and the atmosphere field, and the intake speed of the intake of the middle air inlet pipe 4, the side air inlet pipe 5, and the side air intake device is much smaller than the intake speed of the bottom air intake device.

[0035] In this embodiment, the heating device 3 further has an upper heating element 32 located above the conveying device 2. Both the lower heating element 31 and the upper heating element 32 adopt the prior art and are heating rods arranged through the furnace chamber 11. Preferably, the air outlet of each middle air inlet pipe 4 and each side air inlet pipe 5 is located below the upper heating element 32 and above the conveying device 2, and the openings of the air outlets of each middle air inlet pipe 4 and each side air inlet pipe 5 face downward. The gas entering the furnace chamber 11 through the middle air inlet pipe 4 and the side air inlet pipe 5 is not heated by the upper heating element 32, which is conducive to quickly and efficiently improving the temperature difference. At the same time, the gas entering the furnace chamber 11 through the middle air inlet pipe 4 and each side air inlet pipe 5 directly blows towards the material on the conveying device 2, which is conducive to the full contact between the process atmosphere and the material.

[0036] In this embodiment, the conveying device 2 is the prior art, which includes a plurality of conveying roller rods installed at intervals in sequence and a driving mechanism for driving the conveying roller rods to rotate to convey the material.

[0037] The above are only the preferred embodiments 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: One or more middle inlet pipes (4) for introducing temperature-regulating gas into the middle position of the furnace chamber (11) are installed on the furnace body (1). One or more side inlet pipes (5) for introducing temperature-regulating gas into the side positions of the furnace chamber (11) are provided at the corresponding two side positions of the furnace chamber (11) on the furnace body (1). The roller hearth kiln further includes a temperature-regulating gas supply assembly for introducing temperature-regulating gas into each middle inlet pipe (4) and each side inlet pipe (5), and making the total intake speed of all middle inlet pipes (4) greater than the total intake speed of all side inlet pipes (5) at each side position of the furnace chamber (11). A plurality of middle inlet pipes (4) are installed on the furnace body (1). The outlet of at least one middle inlet pipe (4) among the plurality of middle inlet pipes (4) is at a different height position from the outlets of other middle inlet pipes (4). A plurality of side inlet pipes (5) are installed at the corresponding side position of each side of the furnace chamber (11) on the furnace body (1). The outlet of at least one side inlet pipe (5) among the plurality of side inlet pipes (5) in each group of side temperature-regulating inlet pipe groups is at a different height position from the outlets of other side inlet pipes (5). The temperature-regulating gas supply assembly includes a gas source. All middle inlet pipes (4) are connected to the gas source through a first intake main pipe. A first adjustable flowmeter for adjusting the gas flow rate is provided on the first intake main pipe. All side inlet pipes (5) at each side position of the furnace chamber (11) are connected to the gas source through a second intake main pipe. A second adjustable flowmeter for adjusting the gas flow rate is provided on the second intake main pipe.

2. The roller hearth kiln according to claim 1, characterized in that: The temperature-regulating gas supply assembly includes a gas source. Each middle inlet pipe (4) and each side inlet pipe (5) are connected to the gas source. A third adjustable flowmeter for adjusting the gas flow rate is provided on each middle inlet pipe (4) and each side inlet pipe (5).

3. The roller hearth kiln according to claim 1, characterized in that: Side inlet devices are provided on both side furnace walls of the roller hearth kiln. The side inlet device includes one or more side wall inlet pipelines (6) penetrating through the furnace wall of the furnace body (1) and communicating with the furnace chamber (11), and a side gas supply assembly for introducing gas into the side wall inlet pipelines (6).

4. The roller hearth kiln according to claim 3, wherein: The temperature-regulating gas supply assembly and the side gas supply assembly are the same gas supply assembly. The gas supply assembly includes a preheating intake main pipe (7) and a gas source. The preheating intake main pipe (7) is arranged to penetrate through the furnace chamber (11). One end of the preheating intake main pipe (7) is connected to the gas source. Each middle inlet pipe (4), side inlet pipe (5) and side wall inlet pipeline (6) are connected to the other end of the preheating intake main pipe (7). A fourth adjustable flowmeter for adjusting the gas flow rate is provided on each side wall inlet pipeline (6).

5. The roller hearth kiln according to claim 4, characterized in that: The side inlet device has a plurality of side wall inlet pipelines (6). The plurality of side wall inlet pipelines (6) are arranged at intervals in sequence along the conveying direction of the conveying device (2). The communication ports of each side wall inlet pipeline (6) 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, and the bottom air inlet device includes more than one bottom air inlet pipeline (8) 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 (8).

7. The roller hearth kiln according to claim 6, characterized in that: The heating device (3) has a lower heating element (31) located below the conveying device (2), and a gas blocking and guiding plate is arranged in the furnace chamber (11) below the lower heating element (31). The gas blocking and guiding plate is located above the communication port of the bottom air inlet pipeline (8) and the furnace chamber (11), and enables the gas introduced into the furnace chamber (11) through each bottom air inlet pipeline (8) to flow along the bottom surface of the gas blocking and guiding plate to the periphery of the gas blocking and guiding plate and then enter the furnace chamber (11) above the gas blocking and guiding plate.

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