Roller kiln

Abstract

The utility model provides a roller way kiln. The roller way kiln comprises a hearth main body, a roller way transmission device, a heating device, a temperature control device and an air intake and exhaust device, the furnace chamber is sequentially divided into a plurality of first temperature zones, a plurality of second temperature zones and a slow cooling zone in the material conveying direction. In the heating device, resistance wire heating rods are arranged at the top and the bottom of each first temperature area, and silicon carbon heating rods are arranged at the top and the bottom of each second temperature area. The temperature control device comprises a temperature controller and temperature sensors connected with the temperature controller, a first temperature sensor is arranged in the first temperature area, the top and the bottom of the second temperature area are each provided with a second temperature sensor, and the temperature controller adjusts the heating power accordingly. The air intake and exhaust device is installed in the slow cooling area. Through zone temperature control, differentiated heating rod configuration, multi-point temperature monitoring and slow cooling zone atmosphere adjustment, the temperature field uniformity, the control precision and the product quality stability are remarkably improved, and meanwhile the energy consumption and the equipment maintenance cost are reduced.

Description

Technical Field

[0001] This utility model relates to the field of sintering equipment technology, and more specifically, to a roller kiln. Background Technology

[0002] Roller kilns achieve continuous firing of materials through the rotation of rollers and are widely used in high-temperature processing fields such as ceramic tiles and powder materials. Their mechanized conveying system ensures continuous and automated production; however, traditional equipment suffers from technical bottlenecks such as insufficient temperature field uniformity, poor temperature control stability, and high energy consumption. To address these pain points, developing a new type of roller kiln that combines uniform temperature field, precise control, and economy is of great significance for improving product quality and reducing energy costs in the industry. Utility Model Content

[0003] The technical problems to be solved by this application are insufficient temperature field uniformity, poor temperature control stability and high energy consumption of the equipment. In order to overcome the above defects of the prior art, this application provides a roller kiln.

[0004] This application provides a roller kiln, comprising: a furnace body having a furnace cavity inside, the furnace cavity being divided into multiple first temperature zones, multiple second temperature zones, and a slow cooling zone from front to back along the material conveying direction; a roller conveyor device including a conveyor roller that penetrates the furnace cavity; a heating device including resistance wire heating rods and silicon carbide heating rods, the resistance wire heating rods being disposed at the top and bottom of each first temperature zone, and the silicon carbide heating rods being disposed at the top and bottom of each second temperature zone; a temperature control device including a temperature controller and multiple first temperature sensors and multiple second temperature sensors electrically connected to the temperature controller, the temperature controller being electrically connected to the resistance wire heating rods and silicon carbide heating rods, each first temperature zone having one first temperature sensor, and each second temperature zone having one second temperature sensor at the top and bottom; and an air intake and exhaust device installed in the slow cooling zone for exhausting waste gas from the furnace and adjusting the atmosphere inside the furnace.

[0005] Compared with existing technologies, the roller kiln disclosed in this application has the following advantages: the furnace cavity is divided into a first temperature zone, a second temperature zone, and a slow cooling zone, allowing for segmented temperature control according to the material firing process, improving the uniformity of the temperature field and solving the problem of unstable temperature control in traditional kilns; the first temperature zone uses resistance wire heating rods, and the second temperature zone uses silicon carbide heating rods, combining the heating efficiency advantages of both at different temperature ranges (resistance wire is suitable for medium and low temperature ranges, while silicon carbide rods are suitable for high temperature ranges), achieving precise temperature control and energy saving; the first temperature zone is equipped with a single sensor, and the second temperature zone has sensors at both the top and bottom, monitoring the temperature at different locations in each temperature zone in real time, and achieving closed-loop control in conjunction with a temperature controller, improving temperature control accuracy; the inlet and outlet devices in the slow cooling zone regulate the atmosphere inside the furnace, expelling waste gas, ensuring a stable firing environment, and improving product quality.

[0006] In one possible implementation, there are four first temperature zones and eight second temperature zones. The first two second temperature zones closest to the first temperature zone, together with the four first temperature zones, constitute a heating section, while the remaining six second temperature zones constitute a constant temperature section. Compared with existing technologies, the segmented heating and long-term constant temperature design, with the four first temperature zones and the first two second temperature zones forming a heating section and the latter six second temperature zones forming a constant temperature section, adapts to the requirements of material sintering processes, ensures uniform firing, and reduces defects such as product cracking and deformation. The clearly defined number of temperature zones facilitates standardized production management and improves production capacity consistency.

[0007] In one possible implementation, the first temperature sensor is a K-type thermocouple, and the second temperature sensor is an S-type thermocouple. Compared with the prior art, matching the sensor according to the temperature range improves temperature measurement accuracy and avoids temperature control errors.

[0008] In one possible implementation, the air intake and exhaust device includes an intake duct and an exhaust chimney. The intake duct is located at the bottom of the slow cooling zone and connected to an external induced draft fan. The intake duct has multiple intake holes. The exhaust chimney is located at the top of the slow cooling zone and contains a high-temperature butterfly valve for adjusting the exhaust volume. Compared to existing technologies, the intake duct has multiple intake holes at the bottom, which, together with the top exhaust chimney and high-temperature butterfly valve, form an upward and downward convection airflow path, uniformly displacing the gas inside the furnace and precisely controlling the proportions of oxygen, inert gases, and other atmospheres to meet the atmosphere requirements for sintering different materials. The high-temperature butterfly valve in the exhaust chimney can adjust the exhaust volume according to production needs, preventing waste gas stagnation from affecting the furnace temperature field and reducing heat loss.

[0009] In one possible implementation, the furnace wall of the main body is a double-layer insulation structure, with an inner layer of mullite lightweight bricks and an outer layer of ceramic fiber. Compared with the prior art, the combination of the inner layer of mullite lightweight bricks and the outer layer of ceramic fiber significantly reduces heat loss from the furnace wall, reduces energy consumption, and lowers production costs; it also reduces structural aging caused by excessively high furnace wall temperatures and improves the durability of the kiln.

[0010] In one possible implementation, a powder-coated panel is provided on the outer side of the furnace wall of the main furnace body. Compared with the prior art, the powder-coated panel covers the outer side of the furnace wall, preventing the insulation material from being exposed and damaged, while improving the flatness of the equipment appearance and facilitating cleaning and maintenance.

[0011] In one possible implementation, the rollers of the conveyor roller conveyor are silicon carbide rollers. Compared with the prior art, silicon carbide material has high strength, high temperature resistance, and corrosion resistance, which prevents the rollers from deforming or being damaged at high temperatures, ensures conveying stability, and reduces downtime maintenance costs.

[0012] In one possible implementation, the conveyor rollers carry three rows of saggers per layer. Compared to existing technologies, this method of carrying three rows of saggers per layer optimizes material loading density, ensures uniform heating of each row of saggers, increases production capacity per unit area, and ensures consistent product firing. Attached Figure Description

[0013] Figure 1 This is a front view of this application;

[0014] Figure 2 This is a side view of this application;

[0015] Explanation of reference numerals in the attached figures:

[0016] 1. Furnace body; 11. Furnace cavity; 111. Heating zone; 112. Constant temperature zone; 113. Slow cooling zone; 12. Mullite lightweight brick; 13. Ceramic fiber; 14. Powder-coated hanging panel; 2. Roller conveyor device; 21. Conveyor roller; 3. Silicon carbide heating rod; 4. Second temperature sensor; 5. Air inlet pipe; 51. Air inlet hole; 6. Exhaust chimney. Detailed Implementation

[0017] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0018] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0019] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0020] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] See Figure 1 and Figure 2 This application discloses a roller kiln, including: a furnace body 1, a roller conveyor device 2, a heating device, a temperature control device, and an air intake and exhaust device.

[0022] The furnace body 1 contains a furnace cavity 11, which is divided into multiple first temperature zones, multiple second temperature zones, and a slow cooling zone 113 along the material conveying direction. This partitioning can meet the temperature requirements of the material at different firing stages. The first temperature zones are mainly used for the initial heating of the material, the second temperature zones can achieve further heating and constant temperature control, and the slow cooling zone 113 slowly cools the fired material to avoid problems such as cracking caused by sudden temperature drops. The roller conveyor device 2 includes a conveyor roller 21 that runs through the furnace cavity 11. The conveyor roller 21 carries the material and moves it along the material conveying direction of the furnace cavity 11, realizing continuous material transfer in each zone and ensuring continuous and automated production. The heating device includes resistance wire heating rods and silicon carbide heating rods 3. The resistance wire heating rods are set at the top and bottom of each first temperature zone, that is, on the upper and lower sides of the conveyor roller 21. They can heat the material from both the top and bottom sides simultaneously, reduce heating blind spots, improve heating uniformity, and enable the material to heat up uniformly in the first temperature zone. The silicon carbide heating rods 3 are set at the top and bottom of each second temperature zone, also on the upper and lower sides of the conveyor roller 21. The silicon carbide heating rods 3 have the characteristics of high temperature resistance and oxidation resistance, and are suitable for stable operation in the higher temperature environment of the second temperature zone, ensuring the heating effect and temperature uniformity of the second temperature zone. The temperature control device includes a temperature controller and multiple first temperature sensors and multiple second temperature sensors 4 electrically connected to the temperature controller. The temperature controller is electrically connected to the resistance wire heating rod and the silicon carbide heating rod 3 to control the working status of the heating device. Each first temperature zone is equipped with a first temperature sensor to monitor the temperature of the first temperature zone in real time and transmit the temperature signal to the temperature controller. The temperature controller adjusts the heating power of the resistance wire heating rod according to the signal to achieve precise control of the temperature of the first temperature zone. Each second temperature zone has a second temperature sensor 4 at the top and bottom to monitor the temperature at the top and bottom of the second temperature zone, respectively. Through the temperature feedback from the two sensors, the temperature controller can more accurately understand the temperature distribution of the second temperature zone and adjust the silicon carbide heating rod 3 accordingly to ensure that the temperature of the second temperature zone is uniform and meets the process requirements. The air intake and exhaust device is installed in the slow cooling zone 113 and is mainly used to remove exhaust gas from the furnace and adjust the atmosphere inside the furnace. By reasonably controlling the air intake and exhaust, a suitable atmosphere environment can be provided for the slow cooling process of the material, avoiding the material from reacting with an unfavorable atmosphere and affecting product quality.

[0023] In this embodiment, there are four first temperature zones and eight second temperature zones. The two second temperature zones closest to the first temperature zones, together with the four first temperature zones, constitute a heating section 111 with a length of 8180 mm. The main function of the heating section 111 is to gradually raise the material from its initial temperature to the higher temperature required for firing. The combination of the four first temperature zones and the two first second temperature zones enables staged heating, allowing the material to adapt to gradual temperature changes and preventing defects caused by excessively rapid heating. The remaining six second temperature zones constitute a constant temperature section 112 with a length of 8320 mm. The constant temperature section 112 is used to maintain the material at the stable temperature required for firing, ensuring that the material reacts fully at this temperature and completes the firing process. This segmentation method, combined with the configuration of heating devices in different temperature zones, can better meet the temperature curve requirements of the material firing process, improving product quality and production efficiency. The slow cooling zone 113 has a length of 8000 mm.

[0024] In this embodiment, the first temperature sensor is a K-type thermocouple. K-type thermocouples have advantages such as good linearity, large thermoelectric potential, high sensitivity, good stability and uniformity, strong oxidation resistance, and low price. They are suitable for the temperature measurement range and accuracy requirements of the first temperature zone and can accurately monitor the temperature changes in the first temperature zone. The second temperature sensor 4 is an S-type thermocouple. S-type thermocouples have the characteristics of high accuracy, good stability, and wide temperature measurement range. They are suitable for the higher temperature environment in the second temperature zone and occasions with high temperature measurement accuracy requirements. They can provide accurate signal feedback for temperature control in the second temperature zone.

[0025] In this embodiment, the air intake and exhaust device includes an intake pipe 5 and an exhaust chimney 6. The intake pipe 5 is located at the bottom of the slow cooling zone 113 and is connected to an external induced draft fan. The induced draft fan provides power to introduce external air or other required gases into the slow cooling zone 113 through the intake pipe 5. The intake pipe 5 is provided with multiple intake holes 51, which are evenly distributed to allow the introduced gas to diffuse evenly at the bottom of the slow cooling zone 113, avoiding excessive or insufficient local airflow, thereby better adjusting the atmosphere inside the furnace. The exhaust chimney 6 is located at the top of the slow cooling zone 113 and is used to exhaust the waste gas inside the furnace. The exhaust chimney 6 is provided with a high-temperature butterfly valve for adjusting the exhaust volume. By controlling the opening of the high-temperature butterfly valve, the exhaust volume can be precisely adjusted, thereby controlling the composition and pressure of the atmosphere inside the furnace to meet the requirements of different materials for the furnace atmosphere during the slow cooling process.

[0026] In this embodiment, the furnace wall of the main furnace body 1 has a double-layer insulation structure. The inner layer is made of mullite lightweight brick 12, which has advantages such as high temperature resistance, low thermal conductivity, low bulk density, high strength, and good thermal shock resistance. It can effectively prevent heat loss from the furnace to the outside and improve the insulation performance of the furnace body. The outer layer is made of ceramic fiber 13, which has advantages such as light weight, high temperature resistance, good thermal stability, low thermal conductivity, low specific heat, and resistance to mechanical vibration. It further enhances the insulation effect of the furnace wall, reduces heat loss, and lowers energy consumption. The double-layer insulation structure design maximizes the insulation performance of the furnace body while ensuring the strength of the furnace wall, which is conducive to maintaining the stability of the furnace temperature and reducing energy consumption.

[0027] In this embodiment, a powder-coated hanging plate 14 is provided on the outer side of the furnace wall of the furnace body 1. The powder-coated hanging plate 14 has the advantages of being beautiful, corrosion-resistant, and wear-resistant. It can protect the furnace wall, prevent the outer side of the furnace wall from being eroded and worn by the external environment, and extend the service life of the furnace body. At the same time, the setting of the powder-coated hanging plate 14 makes the furnace body look cleaner and more beautiful, and facilitates the installation and maintenance of the equipment.

[0028] In this embodiment, the rollers of the conveyor roller 21 are silicon carbide rollers. Silicon carbide rollers have the characteristics of high temperature resistance, high strength, good wear resistance, good thermal conductivity, and excellent thermal shock resistance. They can work stably in the high temperature environment of the furnace cavity 11, withstand the weight of the material and the friction during the conveying process, and ensure the normal operation and long service life of the conveyor roller 21. The use of silicon carbide rollers improves the reliability and stability of the roller conveyor device 2 and adapts to the high temperature and high load working environment of the roller kiln.

[0029] In this embodiment, the conveyor roller 21 carries three rows of saggers in a single layer. The three-row, single-layer arrangement can make full use of the width of the conveyor roller 21, ensuring the stability of material conveying while improving the material conveying efficiency. The saggers are used to load materials, and the three-row arrangement ensures that the materials are evenly distributed during the conveying process, avoiding the imbalance of force on the conveyor roller 21 due to uneven bearing, which would affect the conveying effect. The single-layer arrangement ensures that the height of the saggers is moderate during the conveying process, which facilitates the heating devices in each temperature zone to evenly heat the materials in the saggers, and also helps the materials to cool evenly in the slow cooling zone 113.

[0030] This embodiment describes a roller kiln. During operation, the material is carried by the conveyor rollers 21 and passes sequentially along the furnace cavity 11 through the heating section 111, the constant temperature section 112, and the slow cooling section 113. The heating section 111 consists of four first temperature zones and the first two second temperature zones. Resistance wire heating rods at the top and bottom of the first temperature zones initially heat the material, while silicon carbide heating rods 3 in the first two second temperature zones continue to heat it. The latter six second temperature zones constitute the constant temperature section 112, where the silicon carbide heating rods 3 maintain a high temperature. Temperature sensors in each temperature zone transmit signals to a temperature controller, which adjusts the heating rod power to achieve precise temperature control. After the material reaches the slow cooling section 113, gas is introduced through the air inlet 51 by the bottom air inlet pipe 5 under the action of the induced draft fan. The high-temperature butterfly valve of the top exhaust chimney 6 regulates the exhaust volume, discharging waste gas and adjusting the atmosphere inside the furnace to achieve slow cooling of the material. The beneficial effects include:

[0031] I. Precise and Uniform Temperature Control: The furnace cavity is designed in 11 segments (four first temperature zones, eight second temperature zones, and one slow cooling zone 113), combined with differentiated heating devices (resistance wire heating rods for the first temperature zone and silicon carbide heating rods 3 for the second temperature zone) to match the temperature requirements of different sintering stages; the layout of single-point temperature measurement in the first temperature zone and double-point temperature measurement at the top and bottom of the second temperature zone, combined with closed-loop control of the temperature controller, significantly improves the uniformity and stability of the temperature field, solves the problem of temperature fluctuation in traditional kilns, and reduces product cracking and deformation.

[0032] II. Energy Saving, Consumption Reduction, and Enhanced Durability: Resistance wire rods and silicon carbide rods are deployed according to temperature zone characteristics (medium and low temperature / high temperature range) to leverage their respective energy efficiency advantages; the furnace wall adopts a double-layer insulation structure (mullite lightweight brick 12 inner layer and ceramic fiber 13 outer layer), significantly reducing heat loss. Silicon carbide rollers are resistant to high temperatures and corrosion, ensuring transmission stability and reducing downtime maintenance costs.

[0033] III. Precise Atmosphere Control: The slow cooling zone 113 intake and exhaust devices (bottom multi-hole intake pipe 5 and top exhaust chimney with high-temperature butterfly valve 6) form an upward and downward convection, efficiently removing waste gas and adjusting the atmosphere ratio in the furnace, ensuring a stable firing environment and improving product quality consistency.

[0034] IV. Production Efficiency Optimization: The conveyor roller 21 carries three rows of one-layer saggers, balancing loading density and heating uniformity; the clearly defined temperature zones (heating / constant temperature sections) facilitate standardized management, improving capacity and product consistency. The powder-coated hanging plate 14 protects the furnace wall and simplifies maintenance.

[0035] In the description of the embodiments of this application, it should be noted that the terms "inner" and "outer" and other terms indicating direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0036] In the description of this application, the references to terms such as "an embodiment," "some embodiments," "in this embodiment," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0037] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A roller kiln, characterized in that, include: The furnace body has a furnace cavity inside, which is divided into multiple first temperature zones, multiple second temperature zones and a slow cooling zone from front to back along the material conveying direction. The roller conveyor device includes a conveyor roller conveyor that runs through the furnace cavity; A heating device includes a resistance wire heating rod and a silicon carbide heating rod, wherein the resistance wire heating rod is disposed at the top and bottom of each first temperature zone, and the silicon carbide heating rod is disposed at the top and bottom of each second temperature zone; A temperature control device includes a temperature controller and multiple first temperature sensors and multiple second temperature sensors electrically connected to the temperature controller. The temperature controller is electrically connected to the resistance wire heating rod and the silicon carbide heating rod. Each first temperature zone is provided with a first temperature sensor, and each second temperature zone is provided with a second temperature sensor at the top and bottom. The intake and exhaust system is installed in the slow cooling zone to remove exhaust gas from the furnace and adjust the atmosphere inside the furnace.

2. The roller kiln according to claim 1, characterized in that, There are four first temperature zones and eight second temperature zones. The first two second temperature zones closest to the first temperature zone and the four first temperature zones together constitute the heating zone, and the other six second temperature zones together constitute the constant temperature zone.

3. The roller kiln according to claim 2, characterized in that, The first temperature sensor is a K-type thermocouple, and the second temperature sensor is an S-type thermocouple.

4. The roller kiln according to claim 1, characterized in that, The intake and exhaust device includes an intake pipe and an exhaust chimney. The intake pipe is located at the bottom of the slow cooling zone and is connected to an external induced draft fan. The intake pipe has multiple intake holes. The exhaust chimney is located at the top of the slow cooling zone and has a high-temperature butterfly valve for adjusting the exhaust volume inside.

5. The roller kiln according to claim 1, characterized in that, The furnace wall of the main body of the furnace is a double-layer insulation structure, with the inner layer being mullite lightweight brick and the outer layer being ceramic fiber.

6. The roller kiln according to claim 5, characterized in that, The outer side of the furnace wall of the main furnace body is equipped with a powder-coated hanging plate.

7. The roller kiln according to claim 1, characterized in that, The rollers of the conveyor roller table are silicon carbide rollers.

8. The roller kiln according to claim 1, characterized in that, The conveyor roller conveyor carries three rows of saggers in one layer.

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