An ultra-fine powder continuous drying device

Abstract

The present invention discloses a continuous drying device for ultrafine powder, belonging to the technical field of continuous drying equipment for ultrafine powder. An atomizer is arranged at the upper end of the heat exchanger body. A feeding screw is arranged at the upper end of the atomizer. Air inlets one, two, three and four are symmetrically arranged along the circumferential direction at the upper end of the heat exchanger body. A gas flow balance high-pressure blower is arranged at the upper end of the heat exchanger body. A hot air confluence cavity is arranged at the upper end of the heat exchanger body opposite to the gas flow balance high-pressure blower. The gas compressor is connected with a compressed gas heating furnace through a ventilation pipeline. The compressed gas heating furnace transports the heated compressed gas into the heat exchanger body through an atomizer air inlet pipe and a pulse dust removal air inlet pipe. This continuous drying device for ultrafine powder has more thorough drying, lower energy consumption and shorter time.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultra-fine powder continuous drying equipment, and particularly relates to an ultra-fine powder continuous drying device. Background Art

[0002] Nowadays, many fields tend to add rare earths to improve the comprehensive performance of materials. By utilizing the unique electronic layer structure of rare earth elements and their characteristics of easily forming complexes, a variety of rare earth functional additives can be prepared, which can not only improve the mechanical properties of silicone rubber, enhance its heat resistance and flame retardancy, but also have a significant effect on endowing it with new functions.

[0003] Currently, the rare earth ultra-fine powder drying device on the market is a fluidized bed drying device. Its drying principle is as follows: When the powder enters the machine from the fluidized bed feed port, under the action of the vibration force, the powder is tossed along the horizontal fluidized bed and continuously moves forward. The hot air passes upward through the fluidized bed and exchanges heat with the powder. The wet air is discharged after being separated and dust-removed by the cyclone separator, and the dried powder is discharged through the discharge port. However, during the process of the powder moving forward by tossing, it is in a lump or block form. When the hot air passes upward through the fluidized bed and exchanges heat with the powder, the heat exchange is only carried out on the surface of the powder lump or block. When the powder is in a lump or block form, the heating specific surface area is small and the heat conduction is slow. When the heat exchange time is increased to make the heat exchange sufficient, the energy consumption becomes high. The ultra-fine powder discharged from the dust collector will change the original particle size range distribution of the product and change the product quality. Restricted by the structure of the fluidized bed, it is difficult to completely isolate oxygen from the powder, making it difficult to complete the drying process for combustible ultra-fine powder.

[0004] Therefore, in view of this situation, there is an urgent need to design and produce an ultra-fine powder continuous drying device to meet the actual use requirements. Summary of the Invention

[0005] The purpose of the present invention is to provide an ultra-fine powder continuous drying device to solve the problems raised in the above background art.

[0006] To achieve the above purpose, the present invention provides the following technical solution: An ultra-fine powder continuous drying device, comprising:

[0007] A heat exchanger, a gas compressor, and a gas heating furnace for heating the gas from the blower;

[0008] An atomizer is arranged at the upper end of the heat exchanger, a feeding screw is arranged at the upper end of the atomizer, air inlets one, two, three, and four are symmetrically arranged along the circumferential direction at the upper end of the heat exchanger, a gas flow balance high-pressure blower is arranged at the upper end of the heat exchanger, and a hot air confluence cavity is arranged at the position opposite to the gas flow balance high-pressure blower at the upper end of the heat exchanger;

[0009] The gas compressor is connected to the compressed gas heating furnace through a ventilation duct, and the compressed gas heating furnace transports the heated compressed gas to the inside of the heat exchanger through the atomizer inlet pipe and the pulse dust removal inlet pipe.

[0010] Preferably, a heated compressed gas inlet is provided on one side of the atomizer, and an explosion-proof port is provided near the upper end of the heat exchanger close to the atomizer.

[0011] Preferably, a heat exchange area is provided at the lower end of the heat exchanger, and a powder collection area is arranged along the circumferential direction inside the heat exchange area.

[0012] Preferably, a rotary air lock valve II is provided at the lower end of the heat exchange area, and a powder temperature sensor is arranged near the rotary air lock valve II at the lower end of the heat exchange area.

[0013] Preferably, the lower end of the rotary air lock valve II is connected to the rotary air lock valve I through a passivation tank.

[0014] Preferably, a steam evacuation valve is provided at one end of the gas flow balance high-pressure blower.

[0015] The technical effects and advantages of the present invention:

[0016] For this ultrafine powder continuous drying device, 1. The present invention heats the ultrafine powder in a single free state, enables the rare earth ultrafine powder to stay in the heat exchange area for a longer time, makes the drying more thorough, consumes less energy, and takes less time.

[0017] 2. Due to the integration of heating and collection, the interval particle size of the ultrafine powder will not be changed, and its quality will not be affected. In addition, since it is a fully sealed, internal circulation device, as long as the air in the device is replaced with an inert gas, the combustible ultrafine powder can also be heated and dried without causing combustion or explosion, so it is safer, more efficient, and less energy-consuming. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the present invention;

[0019] Figure 2 is a schematic structural diagram of the heat exchanger of the present invention;

[0020] Figure 3 is a top view of the heat exchanger of the present invention;

[0021] Figure 4 is a schematic diagram of the formation of a hot cyclone inside the heat exchanger of the present invention;

[0022] Figure 5 is a schematic diagram of the ultrafine powder crushing structure inside the heat exchanger of the present invention;

[0023] Figure 6Schematic diagram of powder-gas separation structure in the heat exchanger of the present invention;

[0024] Figure 7 Schematic diagram of water vapor discharge structure in the heat exchanger of the present invention;

[0025] Figure 8 Schematic diagram of hot air temperature control structure in the heat exchanger of the present invention;

[0026] Figure 9 Schematic diagram of explosion-proof measures structure in the heat exchanger of the present invention.

[0027] In the figure: 1. Heat exchanger, 2. Blower, 3. Gas heating furnace, 4. Gas compressor, 5. Compressed gas heating furnace, 6. Feeding screw, 7. Passivation tank, 8. Inlet of heated compressed gas, 9. Atomizer, 10. Explosion-proof port, 11. Hot air deflector I, 12. Hot air deflector II, 13. Hot air deflector III, 14. Hot air deflector IV, 15. Gas flow balance high-pressure blower, 16. Water vapor evacuation valve, 17. Hot air inlet I, 18. Hot air inlet II, 19. Hot air inlet III, 20. Hot air inlet IV, 21. Hot air outlet I, 22. Hot air outlet II, 23. Bag pulse device I, 24. Bag pulse device II, 25. Hot air confluence chamber, 26. High-temperature cloth bag, 28. Differential pressure detection sensor, 29. Heat exchange area, 31. Powder collection area, 32. Inner lining of heat exchanger, 33. Heat exchanger insulation layer, 35. Outer wall of heat exchanger, 37. Powder concentration area, 38. Powder temperature measurement sensor, 39. Powder flow deflector, 40. Vacuum interface, 41. Cover of inner heat confluence chamber, 42. Hot gas recovery pipe of heat exchanger, 43. Hot gas inlet pipe of heat exchanger, 44. Atomizer inlet pipe, 45. Pulse dust removal inlet pipe, 46. Pressure detection gauge inside heat exchanger, 47. Airtight discharging valve I, 48. Airtight discharging valve II. Detailed implementation manners

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0029] The connection method can adopt existing methods such as bonding, welding, bolt connection, etc., subject to actual needs.

[0030] The present invention provides a continuous drying device for ultrafine powder as shown in Figures 1-4 ;

[0031] After the gas in the device enters the gas heating furnace 3 through the blower 2 for heating, it passes through the heat exchange body hot air inlet pipe 43, and enters the heat exchange body 1 through the hot air inlet 17, hot air inlet 2 18, hot air inlet 3 19, and hot air inlet 4 20. Under the guidance of the hot air deflector 1 11, hot air deflector 2 12, hot air deflector 3 13, and hot air deflector 4 14, the hot air moves in the same direction along the inner sleeve 32 of the heat exchange body. The four hot air inlets and the four hot air deflectors are arranged in a stepped manner up and down to form four cyclones in the same direction but at different speeds. The four cyclones in the same direction but at different speeds converge to form a hot air cyclone flow, which enters the powder collection area 31 through the outlet of the inner sleeve 32 of the heat exchanger, enters the hot air converging chamber 25 through the high-temperature cloth bag 26, and enters the blower 2 through the heat exchanger heat recovery pipe 42 under the suction of the blower 2, completing the cycle of gas heating, cyclone formation, and hot air recovery, which repeats itself over and over again.

[0032] exist Figure 5 In the embodiment of a continuous drying device for ultrafine powder shown in the figure, the ultrafine rare earth powder is controlled by the feeding screw 6 and then enters the atomizer 9. The compressed gas generated by the gas compressor 4 is heated by the compressed gas heating furnace 5 and then enters the atomizer 9 through the atomizer air inlet pipe 44 and the atomizer heating compressed gas inlet 8. Under the action of gas crushing, the agglomerated and blocky ultrafine powders are reduced to single particles and ejected from the outlet of the atomizer 9 under the action of airflow. Under the reaction force of the powder flow guide 39, the powder flow spreads in all directions and enters the cyclone belt for heat exchange, thereby achieving the perfect effect of reducing the powder to a single particle and presenting it in a free state.

[0033] exist Figure 6 In the embodiment of a continuous drying device for ultrafine powder shown in the figure, in the heat exchange zone 29, a single free powder flow, under the action of the hot cyclone belt, moves downward in a spiral shape along the liner 32 in the heat exchange zone, and heat exchange is carried out at the same time. When the powder flow passes through the bottom outlet of the liner 32 in the heat exchange zone, a part of the powder enters the powder concentration zone 37, and the other part enters the powder collection zone 31 with the air flow, and adheres to the surface of the high-temperature cloth bag 26, so that the pressure difference between the powder collection zone 31 and the hot air confluence chamber 25 becomes larger. When the pressure difference of the pressure difference detection sensor 28 reaches the set value, the cloth bag pulser 1 23 and the cloth bag pulser 2 24 perform a pulse backblowing action, so that the powder adhered to the surface of the high-temperature cloth bag 26 is separated from the cloth bag, and automatically enters the powder concentration zone 37 downward along the inner side of the outer wall 35 of the heat exchange body, and enters the hot air confluence chamber 25 after the hot gas is separated from the powder. In this way, the powder and gas separation process is completed.

[0034] exist Figure 7In the embodiment of a continuous drying device for ultrafine powder shown in the figure, after the atomized compressed gas and the pulse dust removal gas enter the heat exchanger 1, the air pressure in the heat exchanger 1 will rise, and when the pressure detection gauge 46 in the heat exchanger detects that the set pressure value has been reached, the gas flow balancing high-pressure fan 15 starts to run, and the water vapor exhaust valve 16 automatically adjusts the opening angle according to the pressure change, so that the heat exchanger 1 always maintains a set micro-positive pressure state, so as to achieve the purpose of balancing the intake gas flow and the exhaust gas flow of the heat exchanger, and at the same time, the water vapor is also discharged from the heat exchanger through the water vapor exhaust valve 16 and the air flow balancing high-pressure fan 15 along with the airflow, so as to achieve the purpose of water vapor discharge.

[0035] exist Figure 8 In the embodiment of the ultrafine powder continuous drying device shown, the compressed gas generated by the gas compressor 4 is heated to the set temperature by the compressed gas heating furnace 5 and then enters the heat exchange body 1 through the atomizer air inlet pipe 44 and the pulse dust removal air inlet pipe 45. The air temperature is adjusted by the temperature control device of the compressed gas heating furnace 5, and is not adjusted with the change of the powder temperature. When the powder temperature sensor 38 detects that there is an error between the powder temperature and the set temperature, the gas heating furnace 3 automatically adjusts the heating power and performs PID self-tuning control to ensure the heat required by the heat exchange body during the heat exchange between the powder and the gas, so as to achieve the drying purpose.

[0036] exist Figure 9 In the embodiment of a continuous drying device for ultrafine powders shown, if the ultrafine powder is a combustible powder, the device is evacuated through the vacuum interface 40 before operation, and the compressed gas is replaced with an inert gas, which is injected into the entire device through the compressed gas heating furnace 5 and the atomizer air inlet pipe 44, and maintained at a slightly positive pressure, and is completely isolated from the oxygen outside the device, so that there are no combustion conditions. After the ultrafine powder is dried through heat exchange, it enters the passivation tank through the air shut-off and discharge valve 48 for self-cooling and passivation treatment, so that it will not undergo an oxidation reaction when it is discharged from the device through the air shut-off and discharge valve 47. If the pressure in the heat exchange body 1 rises sharply and cannot be adjusted, the explosion-proof diaphragm of the explosion-proof port 10 automatically opens to release the pressure to the outside, and discharges the pressure to a safe area, thus eliminating the safety hazards when drying combustible ultrafine powders.

[0037] Working principle:

[0038] In this continuous drying device for ultrafine powder, after the gas is heated, a hot air swirling flow is formed inside the heat exchanger 1. After the atomizer 9 crushes and restores the powder material, it is in a single-particle and free form and undergoes saturated heat exchange with the hot air swirling flow. The pulse dust collector performs back blowing dust removal on the high-temperature cloth bag 26 to completely separate the powder and gas for collection. By changing the heating gas medium, combustible powder materials can be heated and dried in the same device without combustion or explosion. Since the powder materials are in a single-particle and free form, the specific surface area of heating contact becomes larger, and the heat required for heating a single particle of powder is very small. As long as the hot air heat is sufficient, the rare earth ultrafine powder can be heated and dried in a very short time, thus achieving a fast, thorough, low-energy consumption, safe and reliable heating and drying effect.

[0039] As described above, it is only a preferred specific embodiment of the invention, but the protection scope of the invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the invention, according to the technical solution and inventive concept of the invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the invention.

Claims

1. An ultra-fine powder continuous drying device, characterized in that, include: A heat exchanger (1), a gas compressor (4), and a gas heating furnace (3) for heating the gas from the blower (2); An atomizer (9) is arranged at the upper end of the heat exchange body (1), a feeding screw (6) is arranged at the upper end of the atomizer (9), an air inlet 1 (17), an air inlet 2 (18), an air inlet 3 (19) and an air inlet 4 (20) are symmetrically arranged at the upper end of the heat exchange body (1) along its circumferential direction, a gas flow balancing high-pressure blower (15) is arranged at the upper end of the heat exchange body (1), a water vapor exhaust valve (16) is arranged at one end of the gas flow balancing high-pressure blower (15), and a hot air converging chamber (25) is arranged at the upper end of the heat exchange body (1) opposite to the gas flow balancing high-pressure blower (15); The gas compressor (4) is connected to the compressed gas heating furnace (5) via a ventilation duct, and the compressed gas heating furnace (5) transports the heated compressed gas into the heat exchange body (1) via an atomizer air inlet pipe (44) and a pulse dust removal air inlet pipe (45); A heating compressed gas inlet (8) is provided on one side of the atomizer (9), and an explosion-proof port (10) is provided on the upper end of the heat exchange body (1) near the atomizer (9); A heat exchange area (29) is provided at the lower end of the heat exchange body (1), a powder collecting area (31) is provided inside the heat exchange area (29) along its circumferential direction, a second air shut-off discharge valve (48) is provided at the lower end of the heat exchange area (29), a powder temperature sensor (38) is provided at the lower end of the heat exchange area (29) near the second air shut-off discharge valve (48), and the lower end of the second air shut-off discharge valve (48) is connected to the first air shut-off discharge valve (47) via a passivation tank (7); A heat exchange zone inner sleeve (32) is provided in the heat exchange zone (29), and a high-temperature cloth bag (26) is provided in the powder collection zone (31). After the atomized compressed gas and the pulse dust removal gas enter the heat exchanger (1), the air pressure in the heat exchanger (1) will rise. When the pressure detection gauge (46) in the heat exchanger detects a set pressure value, the gas flow balance high-pressure blower (15) starts to operate, and the water vapor exhaust valve (16) automatically adjusts the opening angle according to the pressure change, so that the heat exchanger (1) always maintains a set micro-positive pressure state, so as to achieve the purpose of balancing the intake gas flow and the exhaust gas flow of the heat exchanger (1). At the same time, the water vapor is discharged from the heat exchanger (1) through the water vapor exhaust valve (16) and the gas flow balance high-pressure blower (15) along with the air flow, so as to achieve the purpose of water vapor discharge; The temperature of the compressed gas generated by the gas compressor (4) is adjusted by the temperature control device of the compressed gas heating furnace (5) and is not adjusted according to the change of the powder temperature. When the powder temperature sensor (38) detects that there is an error between the powder temperature and the set temperature, the gas heating furnace (3) automatically adjusts the heating power.

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