A microwave drying device for nano calcium carbonate

Abstract

The utility model discloses a kind of microwave drying device for nano calcium carbonate, including device main body, microwave generating system, feeding system, discharging system, temperature control system, tail gas treatment system, waste heat recovery system and finished product collection bin;Feeding system and discharging system are respectively installed in the left and right sides of device main body;Tail gas treatment system is located above discharging system, and is connected with waste heat recovery system;Finished product collection bin is located at the export end of discharging system;Device main body is equipped with microwave conveyor belt and driving motor;Microwave generating system is located at the top of device main body, and temperature control system is located at the front side of device main body;The utility model generates microwave by microwave generator, heats and dries the material inside device main body, and heat energy in waste gas can be used for preheating by waste heat recovery system and tail gas treatment system, reduce overall energy consumption.

Description

Technical Field

[0001] This utility model relates to the field of microwave drying technology, specifically to a microwave drying device for nano-calcium carbonate. Background Technology

[0002] Nano-calcium carbonate, as an important inorganic nanomaterial, is widely used in plastics, rubber, paints, sealants, and coatings due to its small particle size, large specific surface area, and high surface energy, resulting in a continuously growing global market. However, in my country's industrial production of nano-calcium carbonate, drying, as a crucial post-processing step, directly determines many core indicators of the final product. Currently, the industry predominantly uses traditional hot air drying technology, which suffers from drawbacks such as high energy consumption, large temperature fluctuations, and long drying times. In particular, external heat drying can induce capillary-induced agglomeration: during water evaporation, the liquid bridges between particles generate strong capillary forces that cause particles to come into close contact. Subsequently, in a high-temperature environment, the hydroxyl groups on the particle surface undergo dehydration condensation reactions, forming hard agglomerates linked by bridging oxygen bonds. This leads to a decrease in the product's specific surface area, deterioration of dispersibility, and reduction in whiteness, severely restricting high-end applications. Utility Model Content

[0003] The purpose of this invention is to provide a microwave drying device for nano-calcium carbonate that has high drying efficiency, low energy consumption, can effectively inhibit product agglomeration, and is safe and reliable to operate, so as to solve the technical problems of high energy consumption, long drying time, and easy occurrence of hard agglomeration of nanoparticles leading to a decline in product performance in traditional hot air drying technology.

[0004] To solve the above technical problems, the solution adopted by this utility model is as follows: A microwave drying device for nano-calcium carbonate includes a main body, a microwave generating system, a feeding system, a discharging system, a temperature control system, a tail gas treatment system, a waste heat recovery system, and a finished product collection bin. The feeding system and the discharging system are respectively installed on the left and right sides of the main body. The tail gas treatment system is located above the discharging system. The finished product collection bin is located at the outlet end of the discharging system. The main body is equipped with a microwave conveyor belt. The microwave generating system includes a microwave generator and a waveguide. The waste heat recovery system includes a heat exchange device, a waste heat recovery pipeline, and a blower. A drive motor is located on one side of the microwave conveyor belt, and the drive motor is used to drive the rollers inside the microwave conveyor belt to rotate, thereby driving the microwave conveyor belt to work; the microwave generator is fixedly installed at the top of the outside of the main body of the device; several sets of waveguides are provided, located at the top of the inside of the main body of the device, and connected to the microwave generator; the heat exchange device is installed at the outlet of the exhaust gas treatment system and connected to the blower; one end of the waste heat recovery pipe is connected to the heat exchange device, and the other end is connected to the main body of the device; the temperature control system is fixedly installed on the front side of the main body of the device and connected to the microwave generator. The entire device is powered by an external power source; the heat exchange device adopts a plate-and-shell heat exchanger with a huge heat transfer area and a high heat transfer coefficient; the main body of the device is a microwave cavity, and the feeding system, discharging system and exhaust gas treatment system are controlled by an external controller; the "non-thermal effect" of microwaves can break down the hydrogen bond network of water molecules, optimize the mass transfer path, block the process of dehydration condensation of hydroxyl groups on the particle surface to form bridging oxygen bonds, significantly reduce the generation of hard agglomerates, increase the specific surface area of ​​the product by 10%-20%, and significantly improve dispersibility and whiteness, meeting the needs of high-end applications.

[0005] In operation, the microwave generator is activated, and the nano-calcium carbonate to be dried enters the main body of the device through the feeding system and is laid on the microwave conveyor belt. The microwave conveyor belt is driven by a motor to rotate, causing the nano-calcium carbonate to be transported at a uniform speed inside the main body of the device. At the same time, the microwaves generated by the microwave generator are transmitted into the main body of the device through a waveguide at the top of the device, and the nano-calcium carbonate is uniformly heated and dried by the microwaves. The temperature control system monitors the temperature inside the main body of the device in real time and adjusts the power of the microwave generator accordingly to ensure that the drying temperature is always kept within the optimal range required by the process, preventing the nano-calcium carbonate from overheating and deteriorating or from being insufficiently dried. The high-temperature humid air generated by the heating and evaporation of the nano-calcium carbonate is discharged through the exhaust gas treatment system. At the same time, the heat exchange device at the end of the exhaust gas treatment system exchanges the temperature of the high-temperature humid air with the cold air generated by the blower. The heated air is transported to the bottom of the main body of the device through the waste heat recovery pipe and slowly rises to heat the nano-calcium carbonate on the microwave conveyor belt, reducing the microwave energy required to heat the nano-calcium carbonate from room temperature to the evaporation temperature. The dried nano-calcium carbonate is discharged from the main body of the device through the discharge system and collected in the finished product collection bin.

[0006] Furthermore, the feeding system includes a feeding hopper, a screw conveyor, and a feeding sealing valve; the feeding sealing valve is fixedly installed on the left side of the main body of the device; one end of the screw conveyor is fixedly connected to the feeding hopper, and the other end is fixedly connected to the feeding sealing valve. The feeding sealing valve is a star-shaped feeder, forming a physical barrier inside, allowing material to pass through while forming a channel to block microwaves. The nano-calcium carbonate to be dried is poured into the feeding hopper, enters the outlet of the feeding sealing valve through the screw conveyor, is conveyed through the feeding sealing valve to the inside of the main body of the device, and falls onto the microwave conveyor belt for further transport.

[0007] Furthermore, there are two waste heat recovery pipes, namely waste heat recovery pipe A and waste heat recovery pipe B, and one end of each is connected to the heat exchange device; the other end of waste heat recovery pipe A is connected to the main body of the device; the other end of waste heat recovery pipe B is wrapped around the inside of the feed hopper and connected to the exhaust gas treatment system.

[0008] Air heated by the heat exchange device at the tail end of the exhaust gas treatment system is transported through waste heat recovery pipes A and B to the bottom of the main body of the device and the feed hopper, respectively, to heat the nano-calcium carbonate on the microwave conveyor belt and in the feed hopper. The heat in waste heat recovery pipe B on the feed hopper can preheat the nano-calcium carbonate, reducing the microwave energy required to heat the nano-calcium carbonate from room temperature to the evaporation temperature. The heat in waste heat recovery pipe A serves as a supplementary heat source to heat the nano-calcium carbonate inside the main body of the device. While reducing the required microwave energy, the power of the blower can be increased when the microwave heating temperature is insufficient, achieving a hot air drying effect.

[0009] Furthermore, the discharge system includes a discharge sealing valve and a vibrating feeder; the discharge sealing valve is fixedly installed on the right side of the main body of the device; the vibrating feeder is installed below the discharge sealing valve; and the finished product collection bin is located at the bottom of the vibrating feeder. The discharge sealing valve adopts a star-shaped feeder. When the nano-calcium carbonate on the microwave conveyor belt reaches the end, it falls to the inlet of the discharge sealing valve by gravity and is discharged into the vibrating feeder through the discharge sealing valve. The slight vibration of the vibrating feeder causes the nano-calcium carbonate to fall into the finished product collection bin.

[0010] Furthermore, the main body of the device is provided with a heating chamber, a constant temperature chamber and a cooling chamber from left to right; the heating chamber, the constant temperature chamber and the cooling chamber are separated by a metal curtain; the number of waveguides at the top of the heating chamber, the constant temperature chamber and the cooling chamber are different; a group of waveguides is provided with five, arranged in a three-on-left and two-on-right structure.

[0011] The waveguide assembly at the top of the heating cavity is densely packed to rapidly heat the nano-calcium carbonate. The waveguide assembly at the top of the isothermal cavity is more uniformly packed to ensure stable drying temperature for the nano-calcium carbonate. The waveguide assembly at the top of the cooling cavity is more distributed to allow the nano-calcium carbonate to cool slowly, avoiding structural stress or secondary agglomeration of nanoparticles due to excessively rapid cooling. The microwave inlets are arranged in a staggered pattern at the tops of the heating, isothermal, and cooling cavities. By utilizing the asymmetric and staggered distribution of the microwave source, as well as the superposition and mutual influence between the microwave fields generated by the inlets, combined with a mode stirrer, the problem of "uneven microwave field distribution and energy waste" in traditional microwave source layouts is solved. This allows the microwave field to cover the action area efficiently and uniformly, improving the consistency of microwave energy's effect on the target object and the efficiency of energy use.

[0012] Furthermore, the temperature control system includes a temperature sensor, a temperature controller, and a heat dissipation assembly; three temperature sensors are provided, which are respectively fixedly installed on one side of the inner wall of the heating chamber, the constant temperature chamber, and the cooling chamber; the temperature controller is electrically connected to the temperature sensor and the microwave generator; the heat dissipation assembly is fixedly installed on one side of the microwave generator.

[0013] Temperature sensors monitor the temperature inside the three cavities of the main body of the device in real time and transmit the data to the temperature controller for display. The temperature controller sets a temperature value and compares the detected temperature with the set temperature value to adjust the power of the microwave generator to regulate the internal temperature of the main body of the device. When heating is required, the temperature controller controls the microwave generator to start or increase its power output. When the temperature is too high, the controller controls the microwave generator to reduce its power or temporarily shut down. The heat dissipation component cools the microwave generator to prevent it from being damaged or having its lifespan reduced due to overheating, ensuring that the microwave generation system can stably execute the instructions of the temperature controller.

[0014] Furthermore, the exhaust gas treatment system includes a humidity sensor, an exhaust assembly, a gas-liquid separator, a dust filter, and an induced draft fan; the humidity sensor is fixedly installed on the inner wall of the constant temperature chamber; the exhaust assembly includes an exhaust manifold and several exhaust ports; the exhaust ports are located at the top of the heating chamber and the constant temperature chamber, and are provided with matching connecting pipes; the exhaust ports are connected to the exhaust manifold through the connecting pipes; the end of the exhaust manifold is sequentially connected to the dust filter, the heat exchange device, the gas-liquid separator, and the induced draft fan; the exhaust manifold is a bent metal pipe.

[0015] A humidity sensor monitors the humidity inside the constant temperature chamber in real time. When the humidity exceeds a set threshold, the power of the induced draft fan is increased. This causes the high-temperature humid air, heated and evaporated by the nano-calcium carbonate inside, to be rapidly drawn out of the constant temperature chamber through the exhaust assembly under the negative pressure suction of the induced draft fan. Under normal circumstances, the induced draft fan operates at a constant speed, transporting the extracted high-temperature humid air through the exhaust assembly to a dust filter for filtration. After heat exchange, the exhaust gas, after being cooled by heat exchange, enters a gas-liquid separator to condense the moisture in the air into water droplets. The water droplets are discharged from the gas-liquid separator through an external drain pipe. The dried gas is then discharged from the exhaust assembly through the induced draft fan. Microwaves can be refracted through the bent metal pipe, attenuating the microwave energy and ensuring that the microwave transmission to the outlet of the exhaust assembly is within a safe range.

[0016] Furthermore, the top of the main body of the device is equipped with an atomizing humidification device. The atomizing humidification device is connected to an external water source via a pipe.

[0017] When the humidity sensor detects that the humidity inside the constant temperature cavity is lower than the set threshold, the atomizing humidification device is activated, atomizing the water into water mist, so that the humidity inside the constant temperature cavity rises evenly in a short time, thereby making the constant temperature cavity reach the most suitable humidity environment, maximizing the interaction efficiency between microwave energy and materials and environment, reducing the decline in material quality under low humidity conditions and the ineffective consumption of microwave energy under high humidity conditions.

[0018] Furthermore, an observation window is provided on the front side of the main body of the device. Operators can observe the color and morphological changes of the nano-calcium carbonate in real time through the observation window to determine whether the drying process is normal.

[0019] The working principle of this utility model is as follows: In operation, the microwave generator is activated, and the nano-calcium carbonate to be dried is poured into the feed hopper. After initial heating through waste heat recovery pipe B, it is conveyed by a screw conveyor to the feed sealing valve. From there, it is transported to the microwave conveyor belt in the heating chamber inside the main body of the device. The microwave conveyor belt is driven by a motor, causing the nano-calcium carbonate to move evenly within the main body of the device. The nano-calcium carbonate passes sequentially through the heating chamber, the constant temperature chamber, and the cooling chamber. Simultaneously, microwaves generated by the microwave generator are transmitted through waveguides to the three chambers inside the main body of the device. The heating chamber rapidly heats the nano-calcium carbonate, while the constant temperature chamber... Uniform dehydration at a constant temperature prevents localized overheating or underheating of the nano-calcium carbonate. The cooling chamber allows for natural and slow heat dissipation, avoiding structural stress or secondary agglomeration of the nanoparticles due to rapid cooling. A temperature sensor monitors the temperature inside the microwave cavity in real time and transmits the data to a temperature controller. The controller sets a temperature value, compares the detected temperature with the set value, and adjusts the power of the microwave generator to regulate the internal temperature of the device. This ensures the drying temperature remains within the optimal range required by the process, preventing overheating and deterioration of the nano-calcium carbonate or insufficient drying. A humidity sensor monitors the constant temperature in real time. When the humidity inside the chamber exceeds a set threshold, the rotation frequency of the induced draft fan is increased. This causes the high-temperature, humid air generated by the heating and evaporation of the nano-calcium carbonate inside the device to be rapidly drawn out of the device through the exhaust assembly under the negative pressure of the induced draft fan. The air is then transported through the exhaust manifold to a dust filter for filtration, and then undergoes heat exchange with the cold air generated by the blower. The heated air is then transported to the inside of the device and the feed hopper through waste heat recovery pipes A and B. The heat entering the device from waste heat recovery pipe A serves as a supplementary heat source to further heat the nano-calcium carbonate inside the device. The process involves heating the nano-calcium carbonate in the waste heat recovery pipe B on the feed hopper. This heat initially heats the nano-calcium carbonate, reducing the microwave energy required to heat it from room temperature to its evaporation temperature. After the waste gas is cooled by heat exchange, it enters a gas-liquid separator where the moisture in the gas is condensed into water droplets. The water droplets are discharged from the gas-liquid separator through an external drain pipe. The dried gas is then discharged from the exhaust assembly by an induced draft fan. When the nano-calcium carbonate on the microwave conveyor belt reaches its end, it falls to the inlet of the discharge sealing valve due to gravity and is discharged into the vibrating feeder through the discharge sealing valve. The slight vibration of the vibrating feeder causes the nano-calcium carbonate to fall into the finished product collection bin.

[0020] The beneficial effects of this utility model are as follows: 1. This invention generates microwaves using a microwave generator and transmits them to the main body of the device via a waveguide to heat and dry nano-calcium carbonate. This achieves uniform heating and rapid drying of nano-calcium carbonate, reducing the drying time from several hours in traditional hot air drying to 30-60 minutes, significantly improving drying efficiency. The microwave heating method effectively suppresses the problem of particle agglomeration caused by capillary force in traditional hot air drying. At the same time, microwave heating has low heat loss, reducing energy consumption by 30%-50% compared to traditional hot air drying. The waste heat recovery system and exhaust gas treatment system can use the heat energy in the exhaust gas to preheat the intake air, further reducing overall energy consumption.

[0021] 2. This utility model can effectively prevent microwave leakage through the inlet and outlet sealing valves. The temperature and humidity sensors can detect the temperature and humidity inside the main body of the device in real time, which makes it convenient for the staff to adjust or automatically adjust the microwave output power to ensure that the temperature is stable at 50-80℃, avoid local temperature fluctuations, ensure that the nano calcium carbonate dries quickly under the best process conditions, and significantly inhibit particle agglomeration. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the main structure of this utility model; Figure 2 This is a frontal cross-sectional view of the present invention. Figure 3 This is a top view cross-sectional structural diagram of the present invention; Figure 4 This is a schematic diagram of the exhaust gas treatment system of this utility model; Figure 5 This is a schematic diagram of the cross-sectional structure of the feed hopper of this utility model.

[0023] In the diagram: 1. Main body of the device; 11. Microwave conveyor belt; 12. Drive motor; 13. Atomizing humidification device; 14. Heating chamber; 15. Constant temperature chamber; 16. Cooling chamber; 17. Metal curtain; 2. Microwave generating system; 21. Microwave generator; 22. Waveguide; 3. Feeding system; 31. Feed hopper; 32. Screw conveyor; 33. Feed sealing valve; 4. Discharge system; 41. Discharge sealing valve; 42. Vibrating feeder; 5. Temperature control system; 51. Temperature sensor 52. Temperature controller; 53. Heat dissipation assembly; 6. Exhaust gas treatment system; 61. Humidity sensor; 62. Exhaust assembly; 621. Exhaust main pipe; 622. Exhaust port; 63. Gas-liquid separator; 64. Dust filter; 65. Exhaust fan; 7. Waste heat recovery system; 71. Heat exchanger; 72. Waste heat recovery pipeline; 721. Waste heat recovery pipeline A; 722. Waste heat recovery pipeline B; 73. Blower; 8. Finished product collection bin; 9. Observation window. Detailed Implementation

[0024] 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.

[0025] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model; the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In addition, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, it 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.

[0026] The microwave drying device for nano-calcium carbonate according to this utility model will be further described in detail below with reference to the accompanying drawings: Example 1: A microwave drying device for nano-calcium carbonate includes a main body 1, a microwave generating system 2, a feeding system 3, a discharging system 4, a temperature control system 5, a tail gas treatment system 6, a waste heat recovery system 7, and a finished product collection bin 8. The feeding system 3 and the discharging system 4 are respectively installed on the left and right sides of the main body 1. The tail gas treatment system 6 is located above the discharging system 4. The finished product collection bin 8 is located at the outlet end of the discharging system 4. The main body 1 is equipped with a microwave conveyor belt 11. The microwave generating system 2 includes a microwave generator 21 and a waveguide 22. The waste heat recovery system 7 includes a heat exchange device 71, a waste heat recovery pipe 72, and a blower 73. The microwave conveyor belt 11 is located inside the main body 1. A drive motor 12 is located on one side of the microwave conveyor belt 11. The drive motor 12 is used to drive the roller inside the microwave conveyor belt 11 to rotate, thereby driving the microwave conveyor belt 11 to work. The microwave generator 21 is fixedly installed at the top of the outside of the main body 1. Several sets of waveguides 22 are provided, all located at the top of the inside of the main body 1 and connected to the microwave generator 21. The heat exchange device 71 is installed at the outlet of the exhaust gas treatment system 6 and connected to the blower 73. One end of the waste heat recovery pipe 72 is connected to the heat exchange device 71, and the other end is connected to the main body 1. The temperature control system 5 is fixedly installed on the front side of the main body 1 and connected to the microwave generator 21.

[0027] The working principle of this embodiment is as follows: In operation, the microwave generator 21 is activated. The nano-calcium carbonate to be dried enters the main body 1 of the device through the feeding system 3 and is laid on the microwave conveyor belt 11. The microwave conveyor belt 11 is driven by the drive motor 12, which moves the nano-calcium carbonate at a uniform speed within the main body 1. Simultaneously, the microwaves generated by the microwave generator 21 are transmitted into the main body 1 through the waveguide 22 at the top of the device body 1, uniformly heating and drying the nano-calcium carbonate. The temperature control system 5 monitors the temperature inside the main body 1 in real time and adjusts the power of the microwave generator 21 accordingly to ensure that the drying temperature is always maintained at the minimum required by the process. Within the optimal range, to prevent the nano-calcium carbonate from overheating and deteriorating or from insufficient drying, the high-temperature humid gas generated by the heating and evaporation of the nano-calcium carbonate is discharged through the tail gas treatment system 6. The heat exchange device 71 at the tail of the tail gas treatment system 6 exchanges the heat of the high-temperature humid gas with the cold air generated by the blower 73. The heated air is transported to the bottom of the device body 1 through the waste heat recovery pipe 72 and slowly rises to preheat the nano-calcium carbonate on the microwave conveyor belt 11, reducing the microwave energy required to heat the nano-calcium carbonate from room temperature to the evaporation temperature. The dried nano-calcium carbonate is discharged from the device body 1 through the discharge system 4 to the finished product collection bin 8 for collection.

[0028] Example 2: The difference from Example 1 is that the feeding system 3 includes a feeding hopper 31, a screw conveyor 32, and a feeding sealing valve 33; the feeding sealing valve 33 is fixedly installed on the left side of the main body 1 of the device; one end of the screw conveyor 32 is fixedly connected to the feeding hopper 31, and the other end is fixedly connected to the feeding sealing valve 33; the waste heat recovery pipeline 72 has two sections, namely waste heat recovery pipeline A721 and waste heat recovery pipeline B722, and one end of each is connected to the heat exchange device 71; the waste heat recovery... The other end of pipe A721 is connected to the main body 1 of the device; the other end of waste heat recovery pipe B722 is wound around the inside of the feed hopper 31 and connected to the exhaust gas treatment system 6; the discharge system 4 includes a discharge sealing valve 41 and a vibrating feeder 42; the discharge sealing valve 41 is fixedly installed on the right side of the main body 1 of the device; the vibrating feeder 42 is installed below the discharge sealing valve 41; the finished product collection bin 8 is located at the bottom of the vibrating feeder 42; an observation window 9 is provided on the front side of the main body 1 of the device.

[0029] The nano-calcium carbonate to be dried is poured into the feed hopper 31. The heat from the waste heat recovery pipe B722 on the feed hopper 31 can initially heat the nano-calcium carbonate, reducing the microwave energy required to heat the nano-calcium carbonate from room temperature to the evaporation temperature. Then, it is conveyed by the screw conveyor 32 to the feed sealing valve 33, and then conveyed into the main body 1 of the device. It falls onto the microwave conveyor belt 11 for further transport. The heat from the waste heat recovery pipe A721 serves as a supplementary heat source to heat the nano-calcium carbonate inside the main body 1. During this process, the temperature sensor 51 monitors the temperature inside the cavity of the main body 1 in real time and transmits it to the temperature controller 52 for display and processing. The temperature is then set by the temperature controller 52. The threshold is used to compare the detected real-time temperature with the set value, and then the output power of the microwave generator 21 is adjusted by the control circuit to achieve precise control of the internal temperature of the main body 1 of the device, so as to ensure the stable drying process of nano-calcium carbonate. The nano-calcium carbonate on the microwave conveyor belt 11 is already in a dry state when it is conveyed to the end of the conveyor belt. It falls to the inlet of the discharge sealing valve 41 by gravity and is discharged into the vibrating feeder 42 through the discharge sealing valve 41. The nano-calcium carbonate is evenly shaken into the finished product collection bin 8 by the micro-vibration of the vibrating feeder 42 to complete the collection. The operator can observe the color and shape changes of the nano-calcium carbonate in real time through the observation window to judge whether the drying process is normal.

[0030] The working principle of this embodiment is the same as that of Embodiment 1.

[0031] Example 3: The difference from Example 2 is that the main body 1 of the device has a heating chamber 14, a constant temperature chamber 15, and a cooling chamber 16 arranged sequentially from left to right; a metal curtain 17 separates the heating chamber 14, the constant temperature chamber 15, and the cooling chamber 16; the number of waveguides 22 at the top of the heating chamber 14, the constant temperature chamber 15, and the cooling chamber 16 varies; a group of five waveguides 22 is arranged in a three-on-left, two-on-right configuration; the temperature control system 5 includes a temperature sensor 51, a temperature controller 52, and a heat dissipation assembly 53; three temperature sensors 51 are fixedly installed on one side of the inner wall of the heating chamber 14, the constant temperature chamber 15, and the cooling chamber 16; the temperature controller 52 is electrically connected to the temperature sensor 51 and the microwave generator 21; the heat dissipation assembly 53 is fixed... The exhaust gas treatment system 6 includes a dust filter 64, a humidity sensor 61, an exhaust assembly 62, a gas-liquid separator 63, and an induced draft fan 65. The humidity sensor 61 is fixedly installed on the inner wall of the constant temperature chamber 15. The exhaust assembly 62 includes an exhaust manifold 621 and several exhaust ports 622. The exhaust ports 622 are located at the top of the heating chamber 14 and the constant temperature chamber 15, and are provided with matching connecting pipes. The exhaust ports 622 are connected to the exhaust manifold 621 through the connecting pipes. The end of the exhaust manifold 621 is sequentially connected to the dust filter 64, the heat exchange device 71, the gas-liquid separator 63, and the induced draft fan 65. The exhaust manifold 621 is a bent metal pipe. The top of the constant temperature chamber 15 is provided with an atomizing humidification device 13.

[0032] Two sets of waveguides 22 are arranged at the top of the heating cavity 14, with a relatively dense installation, for rapid heating of the nano-calcium carbonate. Three sets of waveguides 22 are arranged at the top of the isothermal cavity 15, with a relatively uniform installation, to ensure the temperature stability of the nano-calcium carbonate during drying. One set of waveguides 22 is arranged at the top of the cooling cavity 16 to allow the nano-calcium carbonate to cool down slowly, avoiding structural stress or secondary agglomeration of nanoparticles due to excessively rapid cooling. Microwave ports are arranged in a staggered pattern in the heating cavity 14, the isothermal cavity 15, and the cooling cavity 16. At the top, separated in the middle by a metal curtain 17, the microwave source is asymmetrically and staggeredly distributed, and the superposition and mutual influence between the microwave fields generated by the guide port allow the microwave field to cover the area of ​​action efficiently and uniformly. The humidity sensor 61 monitors the humidity inside the constant temperature cavity 15 in real time. When the humidity exceeds the set threshold, the rotation frequency of the exhaust fan 65 is increased, that is, the suction force of the exhaust fan 65 is increased. The high-temperature humid air evaporated by the heating of nano-calcium carbonate inside the constant temperature cavity 15 is then exhausted under the negative pressure suction of the exhaust fan 65. Component 62 is extracted from the main body 1 of the device, and the high-temperature humid gas is transported to the dust filter 64 through the exhaust component 62 for filtration and then heat exchange through the heat exchange device 71. After the exhaust gas is cooled by heat exchange, it enters the gas-liquid separator 63 to condense the moisture in the gas into water droplets. The water droplets are discharged from the gas-liquid separator 63 through the external drainage pipe. The dried gas is discharged from the exhaust component 62 through the induced draft fan 65. Under normal circumstances, the induced draft fan is rotating at a constant speed and slowly draws out the high-temperature humid gas evaporated by heating nano-calcium carbonate through suction. When the humidity is lower than the set threshold, the atomizing humidification device 13 is activated to atomize the moisture into water mist, so that the humidity inside the constant temperature chamber 15 rises evenly in a short time, so that the inside of the main body 1 of the device reaches the most suitable humidity environment, so that the interaction efficiency between microwave energy and materials and environment is maximized, reducing the decline in material quality under low humidity and the ineffective consumption of microwave energy under high humidity. The microwave energy is attenuated by the refraction phenomenon generated by the exhaust component 62 made of bent metal pipe.

[0033] The working principle of this embodiment is the same as that of embodiment 2.

[0034] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A microwave drying apparatus for nano-calcium carbonate, characterized in that: The device includes a main body (1), a microwave generating system (2), a feeding system (3), a discharging system (4), a temperature control system (5), a tail gas treatment system (6), a waste heat recovery system (7), and a finished product collection bin (8); the feeding system (3) and the discharging system (4) are respectively installed on the left and right sides of the main body (1); the tail gas treatment system (6) is located above the discharging system (4); and the finished product collection bin (8) is located at the outlet end of the discharging system (4). The main body (1) of the device is equipped with a microwave conveyor belt (11) and a drive motor (12); the microwave generating system (2) includes a microwave generator (21) and a waveguide (22); the waste heat recovery system (7) includes a heat exchange device (71), a waste heat recovery pipeline (72) and a blower (73). The microwave conveyor belt (11) is located inside the main body (1) of the device; the drive motor (12) is located on one side of the microwave conveyor belt (11), and its output end is fixedly connected to the drive roller inside the microwave conveyor belt (11); the microwave generator (21) is fixedly installed at the top of the outside of the main body (1); the waveguide (22) is provided in several groups, all located at the top of the inside of the main body (1) of the device, and connected to the microwave generator (21); the heat exchange device (71) is installed at the outlet of the exhaust gas treatment system (6) and connected to the blower (73); one end of the waste heat recovery pipe (72) is connected to the heat exchange device (71), and the other end is connected to the main body (1) of the device; the temperature control system (5) is fixedly installed on the front side of the main body (1) of the device and connected to the microwave generator (21).

2. The microwave drying apparatus for nano-calcium carbonate according to claim 1, characterized in that: The feeding system (3) includes a feeding hopper (31), a screw conveyor (32) and a feeding sealing valve (33); the feeding sealing valve (33) is fixedly installed on the left side of the main body (1) of the device; one end of the screw conveyor (32) is fixedly connected to the feeding hopper (31), and the other end is fixedly connected to the feeding sealing valve (33).

3. The microwave drying apparatus for nano-calcium carbonate according to claim 2, characterized in that: The waste heat recovery pipe (72) has two pipes, namely waste heat recovery pipe A (721) and waste heat recovery pipe B (722), and one end of each pipe is connected to the heat exchange device (71); the other end of waste heat recovery pipe A (721) is connected to the main body of the device (1); the other end of waste heat recovery pipe B (722) is wrapped around the inside of the feed hopper (31) and connected to the exhaust gas treatment system (6).

4. The microwave drying apparatus for nano-calcium carbonate according to claim 1, characterized in that: The discharge system (4) includes a discharge sealing valve (41) and a vibrating feeder (42); the discharge sealing valve (41) is fixedly installed on the right side of the main body (1) of the device; the vibrating feeder (42) is installed below the discharge sealing valve (41); the finished product collection bin (8) is located at the bottom of the vibrating feeder (42).

5. The microwave drying apparatus for nano-calcium carbonate according to claim 1, characterized in that: The main body (1) of the device is provided with a heating chamber (14), a constant temperature chamber (15) and a cooling chamber (16) from left to right; a metal curtain (17) is provided between the heating chamber (14), the constant temperature chamber (15) and the cooling chamber (16); the number of waveguides (22) at the top of the heating chamber (14), the constant temperature chamber (15) and the cooling chamber (16) is different; a group of waveguides (22) is provided with five, arranged in a three-on-the-left and two-on-the-right structure.

6. The microwave drying apparatus for nano-calcium carbonate according to claim 5, characterized in that: The temperature control system (5) includes a temperature sensor (51), a temperature controller (52), and a heat dissipation assembly (53); the temperature sensor (51) is provided in three parts, which are respectively fixedly installed on one side of the inner wall of the heating chamber (14), the constant temperature chamber (15), and the cooling chamber (16); the temperature controller (52) is electrically connected to the temperature sensor (51) and the microwave generator (21); the heat dissipation assembly (53) is fixedly installed on one side of the microwave generator (21).

7. A microwave drying apparatus for nano-calcium carbonate according to claim 6, characterized in that: The exhaust gas treatment system (6) includes a dust filter (64), a humidity sensor (61), an exhaust assembly (62), a gas-liquid separator (63), and an induced draft fan (65); the humidity sensor (61) is fixedly installed on the inner wall of the constant temperature chamber (15); The exhaust assembly (62) includes an exhaust manifold (621) and a plurality of exhaust ports (622); the exhaust ports (622) are located at the top of the heating chamber (14) and the constant temperature chamber (15) and are provided with matching connecting pipes; the exhaust ports (622) are connected to the exhaust manifold (621) through the connecting pipes; The end of the exhaust manifold (621) is connected in sequence to the dust filter (64), the heat exchange device (71), the gas-liquid separator (63) and the induced draft fan (65); the exhaust manifold (621) is a bent metal pipe.

8. A microwave drying apparatus for nano-calcium carbonate according to claim 7, characterized in that: The thermostatic cavity (15) is equipped with an atomizing humidification device (13) at the top of its interior.

9. A microwave drying apparatus for nano-calcium carbonate according to claim 1, characterized in that: The device body (1) has an observation window (9) on the front side.

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