Microwave heating high-temperature circulating flash calcining furnace

Abstract

The utility model relates to the technical field of calcining furnaces, in particular to a microwave heating high-temperature circulating flash calcining furnace, which comprises a cylindrical furnace body, a strong wave-transparent layer arranged on the inner wall of the cylindrical furnace body, a fire-resistant furnace lining arranged on the inner wall of the strong wave-transparent layer, a microwave generator arranged on the periphery of the cylindrical furnace body, and a preheater connected with the upper end of the cylindrical furnace body, a dust removal assembly is arranged above the preheater, and a discharging machine is arranged at the lower end of the cylindrical furnace body and connected with a cooling machine. According to the utility model, the microwave generator is used for calcining magnesite, dolomite, limestone, kaolin, clay, illite and the like, can be used for calcining in a reduction furnace or a vacuum reduction furnace, and is also suitable for high-temperature and ultrahigh-temperature flash sintering high-grade refractory materials; the device has the advantages of low investment cost, small occupied area, high resource utilization rate and the like.

Description

Technical Field

[0001] This utility model relates to the field of calcining furnace technology, and specifically provides a microwave-heated high-temperature circulating flash calcining furnace. Background Technology

[0002] Existing kilns suffer from drawbacks such as a narrow range of raw material particle sizes and significant resource waste, failing to fully meet the specific requirements of various industries for light-burned magnesite. Therefore, finding light-burning kilns suitable for small and medium-sized enterprises, requiring less investment, shorter construction periods, and quicker returns has become a top priority in current research.

[0003] Furthermore, the most representative type of magnesite light-calcining kiln is the reverberatory kiln, which has been in use for over 100 years. Despite several modifications, it has not overcome the problems of low resource utilization, high energy consumption, and inadequate environmental protection standards for dust removal, desulfurization, and denitrification. During the kiln modification process, various kiln types emerged, including suspension kilns, fluidized bed kilns, and ordinary rotary kilns. Modifying these kiln types requires large land areas, significant investment, high energy consumption, high power consumption, high dust content in flue gas, and low resource utilization, making it an extremely challenging task. Therefore, the microwave-heated high-temperature circulating flash calcining furnace emerged amidst these difficulties. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a microwave-heated high-temperature circulating flash calcination furnace.

[0005] This utility model is implemented as follows: a microwave-heated high-temperature circulating flash calcination furnace is provided, including a cylindrical furnace body, a highly transparent wave layer is provided on the inner wall of the cylindrical furnace body, a refractory furnace lining is provided on the inner wall of the highly transparent wave layer, a microwave generator is provided on the outer periphery of the cylindrical furnace body, a preheater is connected to the upper end of the cylindrical furnace body, a dust removal component is provided above the preheater, and a discharge machine is provided at the lower end of the cylindrical furnace body, which is connected to a cooler.

[0006] Preferably, the dust removal assembly includes a dust collector, the preheater is connected to the dust collector via a negative pressure pipeline, and the lower end of the dust collector is connected to a negative pressure fan.

[0007] In a further preferred embodiment, the negative pressure fan is connected to a carbon dioxide adsorption tower.

[0008] In a further preferred embodiment, the air outlet duct of the cooler is connected to a cooling fan, and the air outlet of the cooling fan is connected to the lower end of the preheater through the cooling air duct.

[0009] Further preferably, the height-to-diameter ratio of the cylindrical furnace body is 15 to 25:1.

[0010] Further preferably, the high wave-transmitting layer is an aluminum silicate ceramic fiber layer.

[0011] In a further preferred embodiment, a grate screen and a cyclone separator are installed at different cooling positions within the cooler. The grate screen is installed at a material temperature of 1000–1200°C, and the cyclone separator is installed at a material temperature of 150–250°C. The grate screen is used for thermal separation to remove silicon, and the cyclone separator is used for thermal separation to remove calcium.

[0012] In a further preferred embodiment, a thermocouple is installed inside the cylindrical furnace body, and both the thermocouple and the microwave generator are connected to the controller.

[0013] Further preferred, this utility model is applicable to carbonate minerals, silicate minerals such as magnesite, dolomite, limestone, etc., silicate minerals such as kaolin, clay, illite, etc., and aluminosilicate minerals such as bauxite, etc.

[0014] Compared with the prior art, the advantages of this utility model are:

[0015] 1. The thermal energy of this utility model is obtained from the controllable band microwave energy of the microwave generator and converted into thermal energy by relying on the dielectric properties of the material itself. There is no thermal lag in the traditional heat transfer method. Therefore, the heating method of this utility model subverts the old traditional mode. Furthermore, through upper preheating and lower waste heat utilization, energy saving is achieved, and the thermal efficiency reaches more than 70%.

[0016] 2. This novel method boasts low investment costs, a small footprint, and high resource utilization. It can calcine magnesite powder that cannot be used in suspension kilns, rotary kilns, or reverberatory kilns. Due to microwave heating, selective heating is achieved, with temperature control within ±10℃. Based on the different gangue mineral compositions within the magnesite, and considering the differences in hardness under controlled temperature conditions, particle size separation can be achieved through sieving at suitable temperatures, realizing true thermal separation. Furthermore, under controllable power conditions, high-temperature and ultra-high-temperature sintering of advanced refractory materials can be achieved, resulting in high-density sintered products. Attached Figure Description

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0018] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0020] refer to Figure 1This utility model provides a microwave-heated high-temperature circulating flash calcination furnace, including a cylindrical furnace body 1. A high-transparency layer is provided on the inner wall of the cylindrical furnace body 1, and a refractory lining is provided on the inner wall of the high-transparency layer. A microwave generator 2 is arranged on the outer periphery of the cylindrical furnace body 1. A preheater 3 is connected to the upper end of the cylindrical furnace body 1, and a dust removal component is provided above the preheater 3. A discharge machine 5 is provided at the lower end of the cylindrical furnace body 1, and the discharge machine 5 is connected to a cooler 4. The discharge machine 5 is a shaftless screw discharge machine, connected to the cooler 4 via a chute.

[0021] When using the microwave-heated high-temperature circulating flash calcining furnace provided by this utility model to calcine magnesite, the magnesite is first fed into the inlet of the preheater 3 and dusted by the dust removal component. After preheating by the preheater 3, it enters the cylindrical furnace body 1 from the bottom. Inside the cylindrical furnace body 1, microwaves generated by the microwave generator 2 and passing through the cylindrical furnace body 1, the strong wave-transmitting layer, and the refractory furnace lining are used for calcination. After calcination, the magnesite is fed into the cooler 4 through the discharge machine 5. After being cooled by the cooler 4, the product is processed into various particle sizes and packaged.

[0022] As a specific implementation of the dust removal component, the dust removal component includes a dust collector 7, the preheater 3 is connected to the dust collector 7 through a negative pressure pipeline 6, and the lower end of the dust collector 7 is connected to a negative pressure fan 11.

[0023] The negative pressure fan 11 creates negative pressure in the dust collector 7, and then the dust enters the dust collector 7 through the negative pressure pipeline 6.

[0024] In order to recover and utilize the carbon dioxide generated during the calcination process, as an improvement to the technical solution, the negative pressure fan 11 is connected to the carbon dioxide adsorption tower 8.

[0025] Carbon dioxide, passing through negative pressure pipeline 6, dust collector 7, and negative pressure fan 11, enters carbon dioxide adsorption tower 8 for collection, recovery, storage, and utilization.

[0026] In order to recover and utilize heat energy, the air outlet pipe of the cooler 4 is connected to the cooling fan 9, and the air outlet of the cooling fan 9 is connected to the lower end of the preheater 3 through the cooling air pipe 10.

[0027] Cooling fan 4 cools the calcined magnesite with cooling air, and then the heated cooling air is sent to the lower end of preheater 3 through cooling fan 9 and cooling air duct 10 to preheat the magnesite from bottom to top. This improves the efficiency of thermal energy utilization.

[0028] In order to save floor space and increase microwave calcination efficiency, as an improvement to the technical solution, the height-to-diameter ratio of the cylindrical furnace body 1 is 15-25:1.

[0029] Preferably, the high-transparency layer is an aluminum silicate ceramic fiber layer.

[0030] Preferably, a grate screen and a cyclone separator are installed at different cooling positions within the cooler 4. The grate screen is installed at a material temperature of 1000-1200℃, and the cyclone separator is installed at a material temperature of 150-250℃. The grate screen is used for thermal separation to remove silicon, and the cyclone separator is used for thermal separation to remove calcium.

[0031] To adjust the power of the microwave generator 2 according to different ores, as an improvement to the technical solution, a thermocouple is installed inside the cylindrical furnace body 1. Both the thermocouple and the microwave generator 2 are connected to a controller. The thermocouple measures the temperature inside the cylindrical furnace body 1 and transmits the temperature information to the controller, which then controls the microwave transmission power of the microwave generator 2.

[0032] To prevent signal interference during microwave transmission, shielded wires are required for thermocouples.

[0033] Chemical analysis and testing were conducted on the 0-5mm, 0-10mm, and 5-15mm magnesite ore produced by this utility model, and the test results were all qualified.

[0034] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A microwave-heated high-temperature circulating flash calcining furnace, characterized in that, It includes a cylindrical furnace body (1), a high-wave-transparent layer is provided on the inner wall of the cylindrical furnace body (1), a refractory furnace lining is provided on the inner wall of the high-wave-transparent layer, a microwave generator (2) is provided on the outer periphery of the cylindrical furnace body (1), a preheater (3) is connected to the upper end of the cylindrical furnace body (1), a dust removal component is provided above the preheater (3), and a discharge machine (5) is provided at the lower end of the cylindrical furnace body (1), and the discharge machine (5) is connected to a cooler (4).

2. The microwave-heated high-temperature circulating flash calcining furnace according to claim 1, characterized in that, The dust removal assembly includes a dust collector (7), the preheater (3) is connected to the dust collector (7) through a negative pressure pipeline (6), and the lower end of the dust collector (7) is connected to a negative pressure fan (11).

3. The microwave-heated high-temperature circulating flash calcining furnace according to claim 2, characterized in that, The negative pressure fan (11) is connected to the carbon dioxide adsorption tower (8).

4. The microwave-heated high-temperature circulating flash calcining furnace according to claim 1, characterized in that, The air outlet pipe of the cooler (4) is connected to the cooling fan (9), and the air outlet of the cooling fan (9) is connected to the lower end of the preheater (3) through the cooling air pipe (10).

5. The microwave-heated high-temperature circulating flash calcining furnace according to claim 1, characterized in that, The height-to-diameter ratio of the cylindrical furnace body (1) is 15-25:

1.

6. The microwave-heated high-temperature circulating flash calcining furnace according to claim 1, characterized in that, The high-transparency layer is an aluminum silicate ceramic fiber layer.

7. The microwave-heated high-temperature circulating flash calcining furnace according to claim 1, characterized in that, A grate screen and a cyclone separator are installed at different cooling positions in the cooler (4). The grate screen is set at a material temperature of 1000-1200℃, and the cyclone separator is set at a material temperature of 150-250℃. The grate screen is used for thermal separation to remove silicon, and the cyclone separator is used for thermal separation to remove calcium.

8. The microwave-heated high-temperature circulating flash calcining furnace according to claim 1, characterized in that, A thermocouple is installed inside the cylindrical furnace body (1), and both the thermocouple and the microwave generator (2) are connected to the controller.

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