Microwave multi-section efficient heating furnace

Abstract

The utility model discloses a microwave multi-section efficient heating furnace, and belongs to the technical field of roasting furnaces. The heating furnace comprises a furnace body and a heat preservation and insulation layer wrapping the outer side of the furnace body, and a feeding port and a discharging port are formed in the two ends of the furnace body respectively; the furnace body is installed on the supporting frame through the furnace body rotation unit, and the furnace body rotation unit is used for driving the heating furnace to rotate; the heating system comprises a plurality of magnetic control units arranged on the inner wall of the furnace body, and the magnetic control units are used for providing microwaves to heat materials in the furnace; and the material conveying system is used for conveying the materials into the furnace body from the feeding hole to be treated, and conveying the materials treated by the furnace body to the next working procedure through the discharging hole. The energy utilization efficiency is greatly improved, meanwhile, due to instantaneity and integrity of microwave heating, the roasting time is obviously shortened, meanwhile, the change of the temperature in the furnace is effectively controlled, and the energy utilization efficiency and the product quality are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of roasting furnaces, and particularly relates to a microwave multi-stage high-efficiency heating furnace. Background Technique

[0002] A rotary kiln is a thermal processing equipment for heating bulk or slurry materials. It is a heavy-duty, extra-long, and hyperstatic mechanical operation system, which is widely used in industries such as metallurgy, chemical industry, building refractory materials, and environmental sanitation. According to the different materials it processes, it can be divided into cement rotary kilns, metallurgical and chemical rotary kilns, and lime rotary kilns.

[0003] At present, most traditional rotary kilns are countercurrent rotary kilns. The heating method usually uses coal or other combustible substances to roast the materials. The high-temperature flue gas generated during the combustion of the fuel as the heating source not only has an important impact on the final quality of the product, but also causes great pollution to the environment. At the same time, the flue gas generated during the combustion process will seriously affect the atmosphere environment required during the roasting process of some materials. During the heating process of the rotary kiln, the heating source in the kiln is usually at a fixed end of the rotary kiln, which makes it difficult to control the temperature distribution inside the kiln body.

[0004] Moreover, the traditional rotary kiln heats the materials from the outside to the inside, with low heating efficiency and being affected by the agglomeration of the materials and the amount of materials inside the kiln, which will lead to uneven heating and unsatisfactory roasting effect.

[0005] In the prior art, the patent CN218936978U discloses a microwave-coupled rotary kiln system, which includes a rotary kiln and front and rear microwave devices. In the direction from the kiln tail to the kiln head, the rotary kiln is composed of a preheating section, a roasting section, and a constant temperature section connected in series in sequence. The rear microwave device is arranged before the preheating section of the rotary kiln, and the front microwave device is arranged after the constant temperature section of the rotary kiln. Both of them rotate together with the rotary kiln. The feed inlet of the rotary kiln is arranged on the rear microwave device, and its discharge outlet is arranged on the front microwave device. This equipment effectively improves the use efficiency of fuel, that is, it realizes the rapid reduction of iron oxide to metallic iron, and at the same time avoids local high temperature, resulting in ring formation and affecting the product quality. However, the main focus of this equipment is on the rapid reduction of iron oxide to metallic iron and the merger and growth of metallic iron particles. Microwave only plays a role in enhancing the coupling effect in this equipment. During the mineral calcination process, it mainly still relies on fuel combustion to supply heat energy, and the reducing gases such as carbon monoxide provided during the fuel combustion process will have a certain impact on the materials requiring other atmosphere environments. These situations all lead to certain limitations of this equipment.

[0006] Patent CN117588933A discloses a rotary kiln calcination device using microwave heating, which includes a feeding system, an air inlet system, a calcination heating system, and a discharging and cooling system; the calcination heating system includes a kiln body support unit and a rotary kiln body with a number of magnetrons arranged on the inner wall; the feeding system and the air inlet system are both connected to the inlet of the rotary kiln body; the discharging and cooling system is connected to the outlet of the rotary kiln body. This device uses microwave heating, which can make the materials in the rotary kiln be heated as a whole by themselves, shorten the calcination time, and reduce the sintering temperature; by setting a layer of silicon nitride material on the exposed surface of the firebrick, the uniformity of the temperature distribution in the sintering cavity is improved, the production energy consumption is reduced, and the product quality is improved. The magnetrons are distributed in various parts of the rotary kiln, and the distribution mode of the magnetrons in the rotary kiln can be flexibly designed according to the calcination requirements, and the power of each magnetron can be adjusted in real time. Although this device provides different functional zones for different roasting requirements through the distribution of magnetrons, since it does not pay attention to the movement of materials in the furnace cavity, it is impossible to effectively ensure that the roasting time and effect of materials in different stages reach the expected value. At the same time, in order to ensure the atmosphere requirements during the roasting process, this device integrates the air inlet system at the feeding port. However, since the air flow moves from the feeding port to the discharging port, the waste gas in the previous stage of the roasting process will become the atmosphere environment in the next stage of the roasting process, which is not conducive to maintaining the atmosphere environment required for material roasting. Utility Model Content

[0007] In order to solve the above problems, the technical solution adopted by the present utility model is as follows:

[0008] A microwave multi-stage high-efficiency heating furnace, comprising:

[0009] A support frame;

[0010] A heating furnace, the heating furnace includes a furnace body and a heat-insulating layer covering the outside of the furnace body, and a feeding port and a discharging port are respectively arranged at both ends of the furnace body;

[0011] A furnace body rotation unit, the furnace body is installed on the support frame through the furnace body rotation unit, and the furnace body rotation unit is used to drive the heating furnace to rotate;

[0012] A heating system, the heating system includes a number of magnetron units arranged on the inner wall of the furnace body, and the magnetron units are used to provide microwaves to heat the materials in the furnace;

[0013] A material conveying system, the material conveying system conveys materials from the feeding port into the furnace body for processing, and conveys the materials processed by the furnace body to the next process through the discharging port.

[0014] Further, the heat-insulating layer includes a composite alumina cylinder layer and a heat-insulating fireclay brick layer arranged in sequence from inside to outside.

[0015] Further, the furnace body is a roasting furnace body that is inclined with a higher inlet end and a lower outlet end, and the inclination angle is 4° to 10°.

[0016] Further, microwave shielding devices are provided at both the inlet and outlet of the furnace body to prevent microwave leakage.

[0017] Further, the furnace body rotation unit includes rotary gear bodies fixedly connected to both ends of the furnace body, a rotary motor provided on the support frame, a gearbox provided on the support frame and drivingly connected to the rotary motor, and a supporting wheel drivingly connected to the output end of the gearbox. Among them, the rotary gear body is rotatably connected to the support frame, and the supporting wheel meshes with the rotary gear body.

[0018] Further, a temperature control system is also included. The temperature control system includes a temperature measurement unit and a temperature control unit. The temperature measurement unit includes a plurality of thermocouples uniformly arranged on the inner wall of the furnace body, an infrared temperature sensor and an infrared imager provided outside the furnace body. The plurality of thermocouples, the infrared temperature sensor, and the infrared imager are all electrically connected to the temperature control unit.

[0019] Further, the material conveying system includes a cooling system, a rear conveyor belt, and a diversion trough provided in the furnace body. The cooling system is provided at the discharge port to cool the material entering the discharge port; the diversion trough diverts the material entering the furnace body through the feed port to the discharge port; the rear conveyor belt is correspondingly arranged with the discharge port to unload the processed material onto the rear conveyor belt.

[0020] Further, a protective gas conveying system is also included. The protective gas conveying system includes a plurality of gas conveying ports uniformly distributed above the furnace body. The gas conveying ports penetrate through the heat insulation layer and communicate with the furnace cavity of the furnace body, and check valves are installed in the gas conveying ports.

[0021] Further, a tail gas recovery and purification system is also included. The tail gas recovery and purification system includes a sedimentation chamber installed at the discharge port, and the sedimentation chamber is provided with a tail gas collection port; the sedimentation chamber is used for re-collecting the material dust and smoke raised during the roasting rotation process and reducing the processing pressure of the tail gas collection device.

[0022] Further, the magnetron unit is composed of a plurality of magnetrons that are distributed around the cross-section of the furnace body in a week and are installed in different cross-sections to distinguish multiple-stage roasting zones.

[0023] The beneficial effects of the present utility model:

[0024] (1) A novel microwave multi-stage high-efficiency heating furnace provided by the utility model. Since the essence of microwave heating is that the material itself absorbs microwaves and converts them into heat energy, and the heating method is self-heating, it greatly improves the energy utilization efficiency. At the same time, due to the instantaneity and integrity of microwaves, this enables the device to significantly shorten the roasting time, effectively control the temperature change in the furnace, improve the energy utilization efficiency and the quality of roasted products.

[0025] (2) By setting a diversion groove and gas delivery ports evenly distributed on the kiln body, the device of the utility model ensures different roasting requirements of the material during the roasting process, can accurately control the conveying direction and speed of the material in the furnace, and meets different air intake requirements.

[0026] (3) Through the sedimentation chamber and the tail gas recovery and purification system, the utility model reduces the material loss and the impact of harmful gases generated during the roasting process on the environment. At the same time, the waste heat exchanger on the tail gas recovery and purification system provides efficient utilization of the heat generated by the material under microwave conditions.

[0027] (4) This device can not only be used for heating and roasting, but also for material treatment systems with other requirements, such as microwave pyrolysis, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of a microwave multi-stage high-efficiency heating furnace;

[0029] Among them, 1, furnace body; 2, support frame; 3, heat insulation layer; 4, feed inlet; 5, discharge outlet; 6, rotary motor; 7, magnetron unit; 8, diversion groove; 9, gas delivery port; 10, sedimentation chamber. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The utility model provides a microwave multi-stage high-efficiency heating furnace. The technical solution of the utility model will be described in detail below with reference to the drawings to make it easier to understand and master.

[0031] Embodiment 1

[0032] Reference Figure 1 , a microwave multi-stage high-efficiency heating furnace, comprising:

[0033] Support frame 2;

[0034] Heating furnace, the heating furnace includes a furnace body 1 and a heat insulation layer 3 coated on the outside of the furnace body 1, and a feed inlet 4 and a discharge outlet 5 are respectively arranged at both ends of the furnace body 1;

[0035] Furnace body rotary unit, the furnace body is installed on the support frame 2 through the furnace body rotary unit, and the furnace body rotary unit is used to drive the heating furnace to rotate;

[0036] Heating system, the heating system includes a number of magnetron units 7 arranged on the inner wall of the furnace body 1, and the magnetron units 7 are used to provide microwave heating;

[0037] Material conveying system, the material conveying system conveys the material from the feed inlet 4 to the inside of the furnace body 1 for processing, and conveys the material processed by the furnace body 1 to the next process through the discharge outlet 5.

[0038] In this embodiment, the support frame 2 is borne by a frame built of carbon steel.

[0039] In this embodiment, the magnetron unit 7 is composed of a number of magnetrons arranged around the cross-section of the furnace body 1 in a week and installed in different cross-sections to distinguish multi-stage roasting areas.

[0040] Specifically, the power of each magnetron is about 1200W. To ensure that the roasting requirements for different material types and working environments can be met, the position and arrangement of the magnetrons can be flexibly changed. However, each magnetron unit 7 should ensure that there are at least two magnetrons in different directions to ensure the uniformity of microwave heating in the furnace body 1. For example, when different zones such as a transition zone are set in the furnace, this area needs to be quickly heated, and the density of the magnetrons can be appropriately increased to improve the production efficiency of the product. When entering the heat preservation zone, the number of magnetrons of the magnetron unit 7 in the same cross-section can be appropriately reduced to reduce energy consumption.

[0041] In this embodiment, the heat insulation layer 3 includes a composite alumina cylinder layer and an insulating fireclay brick layer arranged in sequence from the inside to the outside.

[0042] Specifically, the inner wall fireproof material of the heat insulation layer 3 uses a composite alumina cylinder that does not absorb microwaves; the fireproof brick used for the outer wall of the heat insulation layer 3 is a fireclay brick, ensuring that there is no heat loss during the heating process and at the same time avoiding the heat insulation layer 3 from absorbing microwaves. A heat insulation and sealing coating that does not absorb microwaves is coated between the two layers of heat insulation refractory bricks to ensure the airtightness and heat preservation ability of the furnace interior; the furnace body 1 is made of metal.

[0043] In this embodiment, the furnace body 1 is a roasting furnace body 1 that is inclined with a high inlet end and a low outlet end, and the inclination angle is 4° to 10°.

[0044] In this embodiment, microwave shielding devices are provided at both the inlet and outlet of the furnace body 1 to prevent microwave leakage. Microwave detectors are provided outside the microwave shielding devices. When the microwave intensity reaches the national safety standard, the system will automatically issue an alarm and turn off the magnetrons.

[0045] In this embodiment, the rotary unit of the furnace body 1 includes rotary gear bodies fixedly connected to both ends of the furnace body 1, a rotary motor 6 arranged on the support frame 2, a gearbox arranged on the support frame 2 and drivingly connected to the rotary motor 6, and a supporting roller drivingly connected to the output end of the gearbox. Among them, the rotary gear body is rotatably connected to the support frame 2, and the supporting roller meshes with the rotary gear body.

[0046] Among them, the supporting roller is responsible for stabilizing the rotation of the furnace body 1, and the rotary motor 6 provides power for the rotation of the furnace body 1; under the same output conditions of the rotary motor 6, the transmission ratio of the gearbox determines the rotation speed of the furnace body 1.

[0047] A microwave multi-stage high-efficiency heating furnace provided in this embodiment further includes a temperature control system. The temperature control system includes a temperature measurement unit and a temperature control unit. The temperature measurement unit includes a plurality of thermocouples uniformly arranged on the inner wall of the furnace body 1, an infrared temperature sensor and an infrared imager arranged outside the furnace body 1. The plurality of thermocouples, the infrared temperature sensor, and the infrared imager are all electrically connected to the temperature control unit.

[0048] Specifically, the temperature measurement system has three parts: thermocouple temperature measurement, infrared temperature measurement, and infrared imaging; the thermocouples are evenly distributed on the inner wall of the furnace body 1 and can output the temperature of the inner wall of the furnace body 1 in real time. The infrared temperature sensor can measure the temperature of the material surface in real time and feedback the temperature difference between the material in the furnace and the inner wall. The infrared imager is responsible for feedbacking the real-time temperature distribution of each part in the furnace and verifying the accuracy of the temperature control effect; the temperature control system receives and displays the data of each temperature measurement system. The operator inputs different temperature curves according to different sintered products. The temperature control system can adjust the rotation speed of the furnace body according to the temperature curve and adjust the power of each magnetron at each position in real time according to the temperature feedback by the temperature control system, so as to ensure that the material temperature strictly follows the preset temperature curve. The temperature control unit sends the command to adjust the rotation speed of the furnace body to the control system of the rotary motor 6, and the control system of the rotary motor 6 adjusts the output rotation speed of the rotary motor 6.

[0049] In this embodiment, the material conveying system includes a cooling system, a rear conveyor belt, and a diversion trough 8 arranged in the furnace body 1. The cooling system is arranged at the discharge port 5 to cool the material entering the discharge port 5; the diversion trough 8 diverts the material entering the furnace body 1 through the feed port 4 to the discharge port 5; the rear conveyor belt is correspondingly arranged with the discharge port 5 to unload the processed material onto the rear conveyor belt.

[0050] Specifically, the feed port 4 uniformly feeds the material into the furnace body 1 at a certain speed. By adjusting the rotation speed of the furnace body 1 in cooperation with the diversion trough 8, the residence time of the material in different zones in the furnace and the conveying speed of the material between different zones are controlled. The discharge port 5 and the cooling system ensure that the processed material is unloaded onto the rear conveyor belt. The feed port 4, the discharge port 5, and the cooling system are closed during the roasting process, which can ensure the airtightness of the furnace body 1.

[0051] A microwave multi-stage high-efficiency heating furnace provided in this embodiment further includes a protective gas delivery system. The protective gas delivery system includes a plurality of gas delivery ports 9 evenly distributed above the furnace body 1. The gas delivery ports 9 penetrate through the heat insulation layer 3 and communicate with the furnace cavity of the furnace body 1. A check valve is installed in the gas delivery ports 9. Among them, the transported gas provides a roasting atmosphere for the materials during the roasting process by changing the atmosphere of the entire environment where the furnace body 1 is located.

[0052] Specifically, the gas delivery ports 9 are evenly distributed directly above the kiln body in a straight line to ensure the uniformity of the atmosphere introduction. At the same time, gas can be selectively introduced into different zones. For example, when the set preheating zone does not require gas injection but needs to quickly dry the materials and send out the remaining moisture, gas can be blown in through the corresponding gas delivery ports 9 to increase the gas flow rate in the furnace and ensure that the moisture is sent out of the furnace cavity. The gas outlet and the tail gas recovery and purification system are installed together to form a gas flow path. According to the actual usage situation, a heat exchanger can be installed at the gas outlet to ensure the reuse of the waste heat in the exhaust gas.

[0053] A microwave multi-stage high-efficiency heating furnace provided in this embodiment further includes a tail gas recovery and purification system. The tail gas recovery and purification system includes a sedimentation chamber 10 installed between the discharge port 5 and the outlet of the furnace body 1. The sedimentation chamber 10 is provided with a tail gas collection port. The sedimentation chamber 10 is used to re-collect and recover the material dust raised during the roasting rotation process and reduce the processing pressure on the tail gas recovery and purification system.

[0054] Specifically, the tail gas recovery and purification system is connected to the gas outlet, and the tail gas generated in the furnace can be cooled and purified into gas meeting the emission standards and then discharged.

[0055] If the special atmosphere tail gas recovery system used for calcination can also purify the tail gas into gas meeting the intake system standards and recover it; the gas outlet is installed at the discharge port 5 and the sedimentation chamber 10 of the cooling system. The sedimentation chamber 10 is mainly used to re-collect the material dust raised during the roasting rotation process and reduce the processing pressure on the tail gas recovery and purification system.

[0056] In other embodiments, according to the actual usage needs, a cooling device can be connected under the rear conveyor belt. The rear conveyor belt stirs the materials while conveying them to ensure the uniformity of the material cooling.

[0057] The technical solutions of the present utility model have been fully described above. It should be noted that the specific implementation manners of the present utility model are not limited by the above description. All technical solutions formed by those of ordinary skill in the art through equivalent transformation or equivalent substitution in terms of structure, method or function and other aspects based on the spirit of the present utility model fall within the protection scope of the present utility model.

Claims

1. A microwave multi-stage high-efficiency heating furnace, characterized in that, Comprising: Support frame; Heating furnace, the heating furnace includes a furnace body and a heat-insulating layer wrapped outside the furnace body, and a feed inlet and a discharge outlet are respectively arranged at both ends of the furnace body; Furnace body rotation unit, the furnace body is installed on the support frame through the furnace body rotation unit, and the furnace body rotation unit is used to drive the heating furnace to rotate; Heating system, the heating system includes a plurality of magnetron units arranged on the inner wall of the furnace body, and the magnetron units are used to provide microwaves to heat the materials in the furnace; Material conveying system, the material conveying system conveys materials from the feed inlet to the furnace body for processing, and conveys the materials processed by the furnace body to the next process through the discharge outlet.

2. The microwave multi-stage high-efficiency heating furnace according to claim 1, wherein The heat-insulating layer includes a composite alumina cylinder layer and a heat-insulating clay brick layer arranged in sequence from inside to outside.

3. The microwave multi-stage high-efficiency heating furnace according to claim 1, wherein, The furnace body is a roasting furnace body with an inclined setting where the inlet end is high and the outlet end is low, and the inclination angle is 4° - 10°.

4. The microwave multi-stage high-efficiency heating furnace according to claim 3, characterized in that, Microwave shielding devices are arranged at both the inlet and the outlet of the furnace body to prevent microwave leakage.

5. The microwave multi-stage high-efficiency heating furnace according to claim 1, wherein The furnace body rotation unit includes a rotary gear body fixedly connected to both ends of the furnace body, a rotary motor arranged on the support frame, a gearbox arranged on the support frame and drivingly connected to the rotary motor, and a supporting wheel drivingly connected to the output end of the gearbox. Among them, the rotary gear body is rotatably connected to the support frame, and the supporting wheel meshes with the rotary gear body.

6. The microwave multi-stage high-efficiency heating furnace according to claim 5, wherein It also includes a temperature control system, the temperature control system includes a temperature measurement unit and a temperature control unit, the temperature measurement unit includes a plurality of thermocouples uniformly arranged on the inner wall of the furnace body, an infrared temperature sensor and an infrared imager arranged outside the furnace body, and the plurality of thermocouples, the infrared temperature sensor, and the infrared imager are all electrically connected to the temperature control unit.

7. The microwave multi-stage high-efficiency heating furnace according to claim 6, wherein, The material conveying system includes a cooling system, a rear conveyor belt, and a diversion trough arranged in the furnace body. The cooling system is arranged at the discharge outlet to cool the materials entering the discharge outlet; the diversion trough diverts the materials entering the furnace body through the feed inlet to the discharge outlet; the rear conveyor belt is arranged corresponding to the discharge outlet to unload the processed materials onto the rear conveyor belt.

8. The microwave multi-stage high-efficiency heating furnace according to claim 1, wherein It also includes a protective gas conveying system, the protective gas conveying system includes a plurality of gas conveying ports uniformly distributed above the furnace body, the gas conveying ports penetrate through the heat-insulating layer and communicate with the furnace cavity of the furnace body, and check valves are installed in the gas conveying ports.

9. The microwave multi-stage high-efficiency heating furnace according to claim 1, characterized in that, It also includes a tail gas recovery and purification system, the tail gas recovery and purification system includes a sedimentation chamber installed at the discharge outlet, and the sedimentation chamber is provided with a tail gas collection port; the sedimentation chamber is used to re-collect the material dust and smoke raised during the roasting rotation process and reduce the processing pressure of the tail gas collection device.

10. The microwave multi-stage high-efficiency heating furnace according to claim 1, characterized in that, The magnetron unit is composed of a plurality of magnetrons distributed around the cross-section of the furnace body for one week, installed in different cross-sections, and distinguishing multiple-stage roasting zones.

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