An electric roller kiln

Abstract

This utility model discloses an electric roller kiln, relating to the field of roller kiln technology. Large temperature differences within the kiln and poor temperature control stability can lead to inconsistent product performance during the sintering process, with some products exhibiting defects such as cracking and deformation due to uneven heating. This utility model includes a roller kiln body and a heating mechanism, with the heating mechanism located inside the roller kiln body. By incorporating the roller kiln body, heating mechanism, resistance wire, and silicon carbide heating element, this utility model first sends the items to be heated into the pre-oxidation zone, where the resistance wire performs gradient preheating, allowing the items to gradually adapt to the heating process. Subsequently, the items are transferred to the high-temperature firing zone via a transmission roller assembly, where the silicon carbide heating element provides uniform and constant-temperature heating. This significantly improves the practicality of the device by minimizing defects such as product cracking and deformation caused by excessive local temperature differences.

Description

Technical Field

[0001] This utility model relates to the field of roller kiln technology, specifically to an electric roller kiln. Background Technology

[0002] In modern industrial production, the processing of various materials places stringent requirements on temperature control and firing environment. The performance of kiln equipment directly affects product quality and production efficiency. Electric roller kilns, as an advanced high-temperature calcination device, have been widely used in the building materials, chemical, and metallurgical industries in recent years.

[0003] Regarding the aforementioned technologies, the applicant believes that when an electric roller kiln is in operation, it adopts a side heating method, which results in low firing thermal efficiency. Especially in the firing zone, the temperature difference inside the kiln is large, and the temperature control stability is poor. During the sintering process, the excessive temperature difference will lead to inconsistent product performance. Some products will have defects such as cracking and deformation due to uneven heating, which greatly limits the improvement of product quality and the expansion of production scope. Utility Model Content

[0004] The purpose of this utility model is to provide an electric roller kiln to solve the problems mentioned in the background art, such as large temperature difference inside the kiln, poor temperature control stability, and inconsistent product performance caused by excessive temperature difference during the sintering process, and defects such as cracking and deformation of some products due to uneven heating.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an electric roller kiln, comprising a roller kiln body and a heating mechanism, wherein the heating mechanism is disposed inside the roller kiln body, and the heating mechanism includes a high-temperature firing zone disposed in the middle part of the roller kiln body, wherein silicon carbide rods are disposed above and below the high-temperature firing zone, a pre-oxidation zone is disposed at one end of the roller kiln body, resistance wires are uniformly disposed below the pre-oxidation zone, fireproof walls are uniformly disposed inside the resistance wires and the high-temperature firing zone, and exhaust vents are uniformly opened below the pre-oxidation zone.

[0006] By adopting the above technical solution, the items to be heated are first sent into the pre-oxidation zone and preheated gradually using resistance wires, allowing the items to gradually adapt to the heating process. Then, the items are transferred to the high-temperature firing zone by the transmission roller group. With the efficient operation of the silicon carbide heating element, the items are heated at a uniform and constant temperature, minimizing defects such as product cracking and deformation caused by excessive local temperature differences, and significantly improving the practicality of the device.

[0007] Preferably, an exhaust fan is provided at the top of the roller kiln body near the pre-oxidation zone, and an exhaust pipe is provided at the input end of the exhaust fan. The end of the exhaust pipe away from the exhaust fan is connected to the exhaust port.

[0008] By adopting the above technical solution, the smoke generated during the processing of goods can be discharged through the smoke exhaust port by utilizing the operation of the smoke exhaust fan.

[0009] Preferably, the interior of the high-temperature firing zone is provided with a first heat insulation layer, which is a zirconium fiber layer.

[0010] By adopting the above technical solution, the No. 1 insulation layer has low thermal conductivity and low heat capacity, which can effectively prevent heat transfer and reduce heat loss.

[0011] Preferably, a second heat insulation layer is provided outside the first heat insulation layer, and the second heat insulation layer is an aluminum silicate layer.

[0012] By adopting the above technical solution, the No. 1 insulation layer can effectively block heat transfer and significantly reduce heat loss in high-temperature environments.

[0013] Preferably, a post-cooling zone is provided at the end of the high-temperature firing zone that is far from the pre-oxidation zone, and a set of drive rollers is uniformly arranged inside the main body of the roller kiln.

[0014] By adopting the above technical solution, heated items can be transported conveniently.

[0015] Preferably, a rapid cooling fan is provided at the top end of the post-cooling zone near the high-temperature firing zone, and air outlets are provided at both the top and bottom of the post-cooling zone. The output end of the rapid cooling fan is connected to the air outlets.

[0016] By adopting the above technical solution, external cold air is drawn in and accelerated to form a high-speed airflow, which is then directed and sprayed onto the surface of the heated object through the air outlet. The principle of forced convection heat transfer is used to achieve rapid heat exchange: when the high-speed cold air comes into contact with the surface of the object, it quickly carries away a large amount of heat, causing the surface temperature of the object to drop sharply in a short time, forming a "rapid cooling" effect.

[0017] Preferably, a cooling fan is provided at the top of the later cooling zone, away from the earlier oxidation zone.

[0018] By adopting the above technical solution, it is convenient to perform gradient cooling on items.

[0019] Preferably, the top of the interior of the post-cooling zone is provided with uniformly spaced mounting slots, a heat extraction fan is installed at the bottom of the mounting slots, and a protective net is installed at the top of the mounting slots.

[0020] By adopting the above technical solution, the high-heat gas accumulated inside the cooling zone can be continuously discharged, forming a hot and cold air circulation.

[0021] Compared with the prior art, the beneficial effects of this utility model are:

[0022] Equipped with a roller kiln body, heating mechanism, resistance wire, and silicon carbide rod, the items to be heated are first sent into the pre-oxidation zone, where they undergo gradient preheating using the resistance wire, allowing them to gradually adapt to the heating process. Subsequently, the items are transferred to the high-temperature firing zone via a transmission roller assembly. With the efficient operation of the silicon carbide rod heating element, the items are heated at a uniform and constant temperature, minimizing defects such as product cracking and deformation caused by excessive local temperature differences, thus significantly improving the practicality of the equipment. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the overall front view of the present invention;

[0025] Figure 3 This utility model Figure 1 Enlarged structural diagram at point A in the middle;

[0026] Figure 4 This utility model Figure 2 Enlarged structural diagram at point B.

[0027] In the diagram: 1. Main body of roller kiln; 2. Drive roller assembly; 3. Post-cooling zone; 4. Quenching fan; 5. Heating mechanism; 501. Exhaust pipe; 502. Exhaust fan; 503. Pre-oxidation zone; 504. Resistance wire; 505. Exhaust port; 506. First insulation layer; 507. Silicon carbide rod; 508. High-temperature firing zone; 509. Second insulation layer; 510. Firebreak wall; 6. Air outlet; 7. Cooling fan; 8. Protective net; 9. Heat extraction fan; 10. Mounting slot. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] Example 1

[0030] Please see Figures 1 to 4This embodiment provides a technical solution: an electric roller kiln, including a roller kiln body 1 and a heating mechanism 5. The heating mechanism 5 is disposed inside the roller kiln body 1. The heating mechanism 5 includes a high-temperature firing zone 508 disposed in the middle part of the roller kiln body 1. Silicon carbide rods 507 are disposed above and below the interior of the high-temperature firing zone 508. There are six sets of silicon carbide rods 507. The silicon carbide rods 507 are rod-shaped resistance heating elements made of high-purity silicon carbide as the main raw material and sintered at high temperature. Its basic working principle is to pass current through an external power supply, and use the resistance characteristics of silicon carbide material itself to generate Joule heat, so that electrical energy is converted into heat energy and radiated outward, thereby heating the surrounding items. In the initial stage of power-on, the resistance of silicon carbide rod 507 increases with temperature (having a positive temperature coefficient of resistance). In the high-temperature firing zone 508, a uniform high-temperature field can be formed, ensuring that the item is heated evenly during the heating process. This effectively avoids problems such as cracking and deformation caused by local temperature differences, meeting the stringent requirements of precision firing processes for temperature uniformity and stability. When selecting components, appropriate models should be chosen according to actual needs. All components required within silicon carbide rod 507 are existing technologies and will not be described in detail below.

[0031] One end of the roller kiln body 1 is equipped with a pre-oxidation zone 503. Resistance wires 504 are evenly arranged below this pre-oxidation zone 503. The basic working principle of the resistance wires 504 is to form a closed circuit through an external power supply. When current flows through the resistance wires 504, the Joule effect is generated by utilizing the material's inherent resistance characteristics, converting electrical energy into heat energy and releasing it through radiation and conduction, thereby heating the surrounding items. In the pre-oxidation zone 503, the resistance wires 504, through reasonable winding design and power configuration, can form a stable medium-temperature heating environment, performing gradient preheating treatment on the incoming items. This allows the items to gradually adapt to temperature changes during the slow heating process, avoiding internal stress concentration caused by sudden temperature increases. This provides a uniform initial temperature base for subsequent high-temperature firing processes, effectively improving the stability and reliability of the overall heating process. When selecting the resistance wires 504, appropriate models should be chosen according to actual needs. All components required within the resistance wires 504 are existing technologies and will not be described further below.

[0032] Fireproof walls 510 are uniformly arranged inside the resistance wire 504 and the high-temperature firing zone 508. Smoke vents 505 are uniformly opened at the bottom inside the pre-oxidation zone 503. A smoke exhaust fan 502 is installed at the top of the roller kiln body 1 near the pre-oxidation zone 503. The basic working principle of the smoke exhaust fan 502 is to drive the impeller to rotate at high speed by a motor, and use centrifugal force or axial thrust to make the air flow in a direction. When the impeller rotates, the blades push the air to move radially or axially, forming a negative pressure area in the smoke exhaust port 505, which draws pollutants such as flue gas and hot gas in the kiln or space into the fan. After being accelerated by the impeller, it is discharged from the air outlet, thereby achieving efficient discharge of harmful gases and air replacement. When selecting the fan, the appropriate model should be selected according to the actual needs. The components required in the smoke exhaust fan 502 are all existing technologies and will not be described in detail below.

[0033] The smoke exhaust fan 502 is equipped with a smoke exhaust pipe 501 at its input end. The end of the smoke exhaust pipe 501 away from the smoke exhaust fan 502 is connected to the smoke exhaust port 505. By utilizing the operation of the smoke exhaust fan 502, the smoke generated during the processing of the items can be discharged through the smoke exhaust port 505.

[0034] The effect achieved by the entire embodiment is as follows: the item to be heated is first fed into the interior of the pre-oxidation zone 503 through the transmission roller group 2, and the resistance wire 504 below the transmission roller group 2 is used for gradient preheating treatment, so that the item gradually adapts to the heating process; then the item is transferred to the high-temperature firing zone 508 through the transmission system of the transmission roller group 2, and the item is uniformly and constantly heated by the efficient operation of the silicon carbide rod 507 heating element, so as to avoid defects such as product cracking and deformation caused by excessive local temperature difference as much as possible, and significantly improve the practicality of the device.

[0035] Example 2

[0036] The high-temperature firing zone 508 is provided with a first heat insulation layer 506, which is a zirconium fiber layer. The first heat insulation layer 506 is provided with a second heat insulation layer 509, which is an aluminum silicate layer.

[0037] The effect achieved by the entire second embodiment is that the heat insulation performance of the high-temperature firing zone 508 can be improved by using the first heat insulation layer 506 and the second heat insulation layer 509, thereby improving the practicality of the device.

[0038] Example 3

[0039] A post-cooling zone 3 is located at the end of the high-temperature firing zone 508 away from the pre-oxidation zone 503. Drive roller sets 2 are evenly arranged inside the main body 1 of the roller kiln. A quenching fan 4 is located at the top of the post-cooling zone 3, near the high-temperature firing zone 508. Air outlets 6 are located at both the top and bottom of the post-cooling zone 3. The output end of the quenching fan 4 is connected to the air outlets 6. The basic working principle of the quenching fan 4 is to drive the impeller to rotate at high speed via a motor, drawing in and accelerating external cold air to form a high-speed airflow, which is then directed through the air outlets 6 to the surface of the heated item. Rapid heat exchange is achieved using the principle of forced convection heat transfer: when the high-speed cold air contacts the surface of the item, it quickly carries away a large amount of heat, causing the surface temperature to drop significantly in a short time, creating a "quenching" effect. When selecting the appropriate model, it should be chosen according to actual needs. All components required in the quenching fan 4 are existing technologies and will not be described further below.

[0040] A cooling fan 7 is installed at the top of the later cooling zone 3, away from the early oxidation zone 503. The basic working principle of the cooling fan 7 is that the impeller is driven by a motor to rotate, which draws in ambient cold air or pre-treated low-temperature airflow and forms a stable airflow through the guide structure, which is evenly applied to the surface of the item to be cooled. When the airflow comes into contact with the item, it gradually removes heat through convection heat transfer, thus achieving gradual cooling. When selecting the fan, the appropriate model should be selected according to the actual needs. All the components required in the cooling fan 7 are existing technologies and will not be described in detail below.

[0041] The top of the interior of the post-cooling zone 3 is evenly provided with mounting slots 10. A heat extraction fan 9 is installed at the bottom of the interior of the mounting slot 10. The basic working principle of the cooling fan 7 and the heat extraction fan 9 is the same, and will not be described in detail here. A protective net 8 is installed at the top of the interior of the mounting slot 10.

[0042] The overall effect of Embodiment 3 is as follows: After the item is heated, it is sent into the interior of the post-cooling zone 3 through the transmission roller group 2. The rapid cooling fan 4 sprays cold air directionally through the air outlet 6 to rapidly cool the surface of the item. Then, the heat extraction fan 9 is started to continuously discharge the high-heat gas accumulated in the cooling zone, forming a hot and cold air circulation. Finally, the cooling fan 7 runs to perform gradient cooling on the item. Through the segmented control of the three-stage cooling process of "rapid cooling - heat dissipation - constant temperature cooling", the cooling efficiency and uniformity of the device are significantly improved, and product stress damage caused by sudden temperature changes is avoided.

[0043] Working principle: The items to be heated are first fed into the pre-oxidation zone 503 through the transmission roller group 2. The resistance wire 504 below the transmission roller group 2 is used for gradient preheating treatment, so that the items gradually adapt to the heating process. Then, the items are transferred to the high-temperature firing zone 508 through the transmission system of the transmission roller group 2. With the efficient operation of the silicon carbide rod 507 heating element, the items are heated at a uniform and constant temperature, which avoids defects such as product cracking and deformation caused by excessive local temperature difference as much as possible, and significantly improves the practicality of the device.

[0044] Finally, after the items are heated, they are sent into the interior of the post-cooling zone 3 via the transmission roller group 2. The rapid cooling fan 4 sprays cold air directionally through the air outlet 6 to quickly cool the surface of the items. Then, the heat extraction fan 9 starts to continuously discharge the high-heat gas accumulated inside the cooling zone, forming a hot and cold air circulation. Finally, the cooling fan 7 runs to perform gradient cooling on the items. Through the segmented control of the three-stage cooling process of "rapid cooling - heat dissipation - constant temperature cooling", the cooling efficiency and uniformity of the device are significantly improved, avoiding product stress damage caused by sudden temperature changes.

[0045] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0046] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An electrothermal roller hearth kiln characterized in that: include: Main body of roller kiln (1); Heating mechanism (5) is located inside the main body (1) of roller kiln. The heating mechanism (5) includes a high-temperature firing zone (508) located in the middle part of the main body (1) of roller kiln. Silicon carbide rods (507) are provided above and below the main body (1) of roller kiln. A pre-oxidation zone (503) is provided at one end of the main body (1) of roller kiln. Resistance wires (504) are uniformly arranged below the main body (503). Fireproof walls (510) are uniformly arranged inside the resistance wires (504) and the high-temperature firing zone (508). Smoke vents (505) are uniformly opened below the main body (503).

2. An electrothermal roller kiln according to claim 1, characterised in that: The top end of the roller kiln body (1) near the pre-oxidation zone (503) is provided with a flue gas fan (502). The input end of the flue gas fan (502) is provided with a flue gas pipe (501). The end of the flue gas pipe (501) away from the flue gas fan (502) is connected to the flue gas outlet (505).

3. An electrothermal roller kiln according to claim 1, characterised in that: The high-temperature firing zone (508) is provided with a first heat insulation layer (506), which is a zirconium fiber layer.

4. An electrothermal roller kiln according to claim 3, characterised in that: A second heat insulation layer (509) is provided on the outside of the first heat insulation layer (506), and the second heat insulation layer (509) is an aluminum silicate layer.

5. An electrothermal roller kiln according to claim 1, characterised in that: The high-temperature firing zone (508) is provided with a post-cooling zone (3) at one end away from the pre-oxidation zone (503), and the roller kiln body (1) is provided with a uniformly arranged transmission roller group (2).

6. An electrothermal roller kiln according to claim 5, characterised in that: A rapid cooling fan (4) is provided at the top end of the post-cooling zone (3) near the high-temperature firing zone (508). Air outlets (6) are provided at the top and bottom of the post-cooling zone (3). The output end of the rapid cooling fan (4) is connected to the air outlets (6).

7. An electrothermal roller kiln according to claim 5, characterised in that: A cooling fan (7) is provided at the end of the top of the post-cooling zone (3) that is far away from the pre-oxidation zone (503).

8. An electrothermal roller kiln according to claim 5, characterised in that: The top of the interior of the post-cooling zone (3) is uniformly provided with mounting slots (10), and a heat extraction fan (9) is provided at the bottom of the interior of the mounting slot (10). A protective net (8) is provided at the top of the interior of the mounting slot (10).

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