Energy-saving tunnel kiln for efficiently drying silicon powder
By adopting an energy-saving tunnel kiln structure and automatic chain plate conveyor in the silicon powder drying equipment, the existing rotary kilns have solved the problem of high energy consumption and slow speed, and the efficient and energy-saving silicon powder drying effect has been achieved.
Patent Information
- Application Number
- CN202422189368.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-06
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2034-09-06
AI Technical Summary
In the existing silicon powder drying technology, the rotary kiln consumes a large energy consumption and slow drying speed, making it difficult to achieve efficient and energy-saving drying effects.
The energy-saving tunnel kiln structure is adopted. By setting a heating shell and an electric heater on both sides of the kiln body, the heat transfer holes are used to evenly distribute the heat after heating into the kiln body, and the automatic continuous drying of silicon powder is achieved through a chain plate conveyor.
It realizes efficient drying of silicon powder, saves a lot of energy consumption, improves drying speed and efficiency, and has a reasonable structure and is easy to promote and use.
Smart Images
Figure CN222849743U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of solid waste resource treatment and processing, and specifically relates to an energy-saving tunnel kiln for efficient drying of silicon powder. Background Art
[0002] In the process of cutting solar-grade polysilicon, powdered cutting waste will be generated. The waste is mainly composed of silicon powder, silicon carbide powder, metal oxides and other impurities. If these wastes are handled at will, it will not only waste resources, but also pollute the environment. In order to avoid the waste of resources, the recycling and reuse of polysilicon waste has become the main technical measure for energy conservation and emission reduction. At present, in addition to being used for casting solar cells, polysilicon waste recycling can also be used to purify and produce industrial silicon by smelting. In the technical process of smelting and purifying industrial silicon with polysilicon waste, in order to improve the purity of high-purity silicon, silicon powder will need to be pickled to remove metal oxides and impurities, etc. After pickling, it needs to be washed and neutralized by water. The humidity of silicon powder after water washing is high, and the silicon powder needs to be dried. At present, the recycling and utilization of silicon powder has just started. The drying of silicon powder is mostly carried out by using a rotary kiln structure. In the process of drying silicon powder, although the rotary kiln can achieve good drying effect, the rotary kiln consumes a lot of heat energy, the energy consumption of the device is large, and the drying speed is slow. Therefore, it is an objective need to develop an energy-saving tunnel kiln for efficient drying of silicon powder which has a reasonable structure, high drying efficiency and low energy consumption. Summary of the invention
[0003] The utility model aims to provide an energy-saving tunnel kiln for high-efficiency drying of silicon powder which has reasonable structure, high drying efficiency and low energy consumption.
[0004] The purpose of the utility model is achieved in this way, including a kiln body and a furnace door, heating shells sealed and connected thereto are arranged on both sides of the kiln body, multiple electric heaters are installed inside each heating shell, an air inlet is arranged on the top of the heating shell, multiple rows of heat transfer holes are processed through the two side walls of the kiln body, an exhaust pipe and a temperature sensor are arranged on the top of the kiln body, a first chain plate conveyor and a second chain plate conveyor are installed at intervals up and down in the kiln body, a feed hopper is arranged on the top of the kiln body above the feeding end of the first chain plate conveyor, a first scraping mechanism is arranged above the first chain plate conveyor near the feed hopper side, the feeding end of the second chain plate conveyor is longer than the discharging end of the first chain plate conveyor, a second scraping mechanism is arranged above the second chain plate conveyor near the side of the guide inclined plate, a discharging chute is obliquely installed on the kiln body below the discharging end of the second chain plate conveyor, and guide inclined plates are obliquely installed on the inner wall of the kiln body above the feeding ends of the first chain plate conveyor and the second chain plate conveyor.
[0005] Compared with the existing technology, the advantages of the device are: first, the device adopts the structure of a tunnel kiln to heat the silicon powder. When in use, the electric heater can heat and dry the silicon powder to be dried during the circulation transportation of the first chain conveyor and the second chain conveyor. The silicon powder is transported and dried by the first chain conveyor and the second chain conveyor. Compared with the traditional rotary kiln structure, automatic feeding, discharging and drying can be realized, and automatic and continuous drying of silicon powder can be realized; second, the structure of the heating device is optimized, and the heat generated by the heating device after heating enters the kiln body through the heat transfer hole, which can ensure that the heat entering the kiln body is evenly distributed, can save a lot of energy consumption, and is conducive to increasing the drying speed of silicon powder, thereby improving the drying efficiency. The device has the advantages of reasonable structure, good drying effect, energy saving and high efficiency, and is easy to promote and use. BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Figure 1 It is a schematic diagram of the overall structure of the utility model;
[0007] Figure 2 It is a side sectional view of the utility model;
[0008] In the figure: 1-kiln body, 2-furnace door, 3-heating shell, 4-electric heater, 5-heat transfer hole, 6-exhaust pipe, 7-temperature sensor, 8-first chain plate conveyor, 9-second chain plate conveyor, 10-feed hopper, 11-material guide inclined plate, 12-discharge chute, 13-connecting frame, 14-lifting cylinder, 15-grabbing teeth, 16-positioning plate, 17-gas burner, 18-waste heat recovery device, 19-air inlet box, 20-air outlet box, 21-baffle, 22-waste heat recovery pipe, 23-circulation pipe, 24-air inlet pipe, 25-air distribution pipe, 26-air nozzle, 27-dehumidifier, 28-drying layer. DETAILED DESCRIPTION
[0009] The present invention is further described below in conjunction with the accompanying drawings, but the present invention is not limited in any way. Any changes or improvements made based on the teachings of the present invention belong to the protection scope of the present invention.
[0010] like Figures 1-2As shown, the utility model comprises a kiln body 1 and a furnace door 2, heating shells 3 sealed and connected thereto are arranged on both sides of the kiln body 1, a plurality of electric heaters 4 are installed inside each heating shell 3, an air inlet is arranged on the top of the heating shell 3, the electric heater 4 adopts the structure used in the prior art, multiple rows of heat transfer holes 5 are processed through the two side walls of the kiln body 1, an exhaust pipe 6 and a temperature sensor 7 are arranged on the top of the kiln body 1, the temperature sensor 7 is the structure used in the prior art, and the finished product can be directly purchased, the temperature sensor can monitor the temperature in the kiln body in time, and then control the opening and closing of the electric heater, so as to achieve a better energy-saving effect, a first chain plate conveyor 8 and a second chain plate conveyor 9 are installed in the kiln body 1 at intervals up and down, and the first chain plate conveyor 8 and the second chain plate conveyor 9 are installed in the kiln body 1 at intervals up and down. A chain conveyor 8 and a second chain conveyor 9 are structures used in the prior art, and finished products can be directly purchased according to the length requirements for use. A feed hopper 10 is arranged on the top of the kiln body 1 above the feeding end of the first chain conveyor 8, and a first scraping mechanism is arranged above the first chain conveyor 8 near the feed hopper 10. The feeding end of the second chain conveyor 9 is longer than the discharging end of the first chain conveyor 8, and a second scraping mechanism is arranged above the second chain conveyor 9 near the guide inclined plate 11. A discharging chute 12 is obliquely installed on the kiln body 1 below the discharging end of the second chain conveyor 9, and guide inclined plates 11 are obliquely installed on the inner wall of the kiln body 1 above the feeding ends of the first chain conveyor 8 and the second chain conveyor 9.
[0011] The working process of this device is: when it is necessary to dry the silicon powder, the electric heater 4 heats the air, and the heated hot air enters the kiln body 1 through the heat transfer hole 5, then the first chain conveyor 8 and the second chain conveyor 9 start to work, and the silicon powder is continuously conveyed to the first chain conveyor 8 through the feed hopper 10. When the silicon powder enters the first chain conveyor 8 through the feed hopper 10, the guide inclined plate 11 can guide the silicon powder to the first chain conveyor 8. When the silicon powder enters the feeding end of the first chain conveyor 8, the first scraping mechanism flattens the silicon powder to make it evenly spread on the first chain conveyor 8. When the silicon powder is transported to the discharge end of the first chain conveyor 8, the guide inclined plate 11 can guide the silicon powder to the feeding end of the second chain conveyor 9. When the silicon powder enters the feeding end of the second chain conveyor 9, the second scraping mechanism flattens the silicon powder to make it evenly spread on the second chain conveyor 9. When the first and second chain conveyors 8 and 9 are at the discharge end of the chain conveyor 9, the dried silicon powder can be discharged from the discharge end of the second chain conveyor 9 through the discharge chute 12. There is no need to open the furnace door 2 to realize the process of feeding, drying, conveying and discharging the silicon powder. During the process of conveying the silicon powder by the first and second chain conveyors 8 and 9, the hot air generated by the electric heater 4 continuously enters the kiln body 1 through the heat transfer holes 5, so as to heat and dry the silicon powder. The silicon powder is conveyed and dried by the first and second chain conveyors 8 and 9. Compared with the traditional rotary kiln structure, a large amount of heat energy can be saved, and automatic and continuous drying of the silicon powder can be realized. The heat generated by the electric heater 4 after heating enters the kiln body 1 through the heat transfer holes 5, so as to ensure that the heat entering the kiln body 1 is evenly distributed, which is beneficial to improve the drying speed of the silicon powder. During the heating process, the exhaust pipe 6 can be used to discharge the hot and humid air in the kiln body 1 in time, so as to further improve the heating speed.
[0012] Furthermore, the first scraping mechanism has the same structure as the second scraping mechanism, both of which include a connecting frame 13, a lifting cylinder 14 and scraping teeth 15. The connecting frame 13 is fixedly mounted on the two side walls of the kiln body 1. There are 1 to 2 lifting cylinders 14, and the cylinder seat of the lifting cylinder 14 is mounted on the connecting frame 13. A positioning plate 16 is installed at the end of the piston rod of the lifting cylinder 14. A plurality of scraping teeth 15 are installed at intervals at the bottom of the positioning plate 16. The lifting cylinder 14 is a structure used in the prior art. The finished product is directly purchased according to the power used and the stroke size. The lifting cylinder 14 can drive the positioning plate 16 to move up and down so as to adjust the distance between the positioning plate 16 and the corresponding chain conveyor. When the chain conveyor is in operation, the scraping teeth 15 can flatten the accumulated silicon powder, thereby improving the drying effect of the silicon powder.
[0013] Furthermore, in order to improve the efficiency of silicon powder heating, gas burners 17 are symmetrically installed on the two side walls of the lower part of the kiln body 1. The gas burner 17 is a structure used in the prior art. The gas burner 17 can assist the electric heater 4. If the heating temperature provided by the electric heater 4 does not meet the requirements of silicon powder drying, the gas burner 17 can be used to increase the temperature of silicon powder heating and drying.
[0014] In order to ensure that the hot air entering the kiln body 1 is uniform and improve the efficiency of heating and drying the silicon powder, the number of heat transfer holes 5 in each row is more than 4, and the heat transfer holes 5 are strip holes.
[0015] In order to improve the utilization rate of thermal energy and reduce the energy consumption of the device, an induced draft fan is installed on the exhaust pipe 6, and a waste heat recovery device 18 is installed at the air outlet end of the exhaust pipe 6. The waste heat recovery device 18 is located above the kiln body 1, and an internal hollow air inlet box 19 and an air outlet box 20 are installed at intervals at both ends of the waste heat recovery device 18. A plurality of baffles 21 are installed in the waste heat recovery device 18 between the air inlet box 19 and the air outlet box 20 in an up and down staggered manner, and a plurality of waste heat recovery pipes 22 are arranged along the bending direction of the plurality of baffles 21 between the air inlet box 19 and the air outlet box 20. A circulation pipe 23 is installed on the waste heat recovery device 18 at the end opposite to the exhaust pipe 6, and a dehumidifier 27 is installed on the circulation pipe 23. A plurality of drying layers 28 are arranged in the dehumidifier 27 along the air flow direction, and the end of the circulation pipe 23 is connected to the air inlet box 19, and an air inlet pipe 24 is installed on the air outlet box 20. An air distribution duct 25 is installed on the top of the kiln body 1, and the air inlet pipe 24 is connected to the air distribution duct 25. The bottom of the air distribution duct 25 is evenly distributed along its length direction. There are multiple air jets arranged at equal intervals. When in use, the hot and humid air discharged from the exhaust pipe 6 has a high temperature, and direct discharge will cause waste. In order to avoid heat waste, the hot and humid air discharged from the exhaust pipe 6 first enters the waste heat recovery device 18, and then enters the dehumidifier 27 through the circulation pipe 23. After dehumidification, the hot and humid air becomes dry hot air and then enters the waste heat recovery pipe 22 through the air inlet box 19. After heat exchange with the hot and humid air that continues to enter the waste heat recovery box 18, the dry hot air with increased temperature enters the air outlet box 20, and then enters the air distribution duct through the air inlet pipe 24, and returns to the kiln body 1 through the air jet to dry the silicon powder. In this way, heat energy can be recycled and better energy-saving effects can be achieved. In order to ensure that the dry hot air entering the kiln body 1 is evenly distributed and improve the drying effect of the silicon powder, an air nozzle 26 is installed on the air outlet. Preferably, the drying layer 28 is made of activated carbon material. The activated carbon adsorption material has low cost and good dehumidification effect.
[0016] In order to ensure the stability of the heating and drying temperature in the kiln body 1, a heat-insulating layer is provided on the inner wall of the kiln body 1. The heat-insulating layer is not drawn in the figure, and the heat-insulating bricks in the prior art can be used for the heat-insulating layer.
Claims
1. An energy-saving tunnel kiln for efficient drying of silicon powder, comprising a kiln body (1) and a furnace door (2), characterized in that: The kiln body (1) is provided with heating shells (3) sealed therewith on both sides, and a plurality of electric heaters (4) are installed inside each heating shell (3). An air inlet is provided at the top of the heating shell (3). The two side walls of the kiln body (1) are penetrated with a plurality of rows of heat transfer holes (5). The top of the kiln body (1) is provided with an exhaust pipe (6) and a temperature sensor (7). A first chain conveyor (8) and a second chain conveyor (9) are installed in the kiln body (1) at intervals in the upper and lower parts. A feed hopper (10) is provided at the top of the kiln body (1) above the feeding end of the first chain conveyor (8). 0), a first scraping mechanism is arranged above the first chain conveyor (8) on the side close to the feed hopper (10), the feeding end of the second chain conveyor (9) is longer than the discharging end of the first chain conveyor (8), a second scraping mechanism is arranged above the second chain conveyor (9) on the side close to the material guide inclined plate (11), a discharging chute (12) is obliquely installed on the kiln body (1) below the discharging end of the second chain conveyor (9), and a material guide inclined plate (11) is obliquely installed on the inner wall of the kiln body (1) above the feeding ends of the first chain conveyor (8) and the second chain conveyor (9).
2. The energy-saving tunnel kiln for efficient drying of silicon powder according to claim 1, characterized in that: The first scraping mechanism and the second scraping mechanism have the same structure, both comprising a connecting frame (13), a lifting cylinder (14) and scraping teeth (15); the connecting frame (13) is fixedly mounted on the two side walls of the kiln body (1); there are 1 to 2 lifting cylinders (14); the cylinder seats of the lifting cylinders (14) are mounted on the connecting frame (13); a positioning plate (16) is mounted on the end of the piston rod of the lifting cylinder (14); and a plurality of scraping teeth (15) are installed at intervals at the bottom of the positioning plate (16).
3. The energy-saving tunnel kiln for efficient drying of silicon powder according to claim 1, characterized in that: Gas burners (17) are symmetrically mounted on both side walls of the lower part of the kiln body (1).
4. The energy-saving tunnel kiln for efficient drying of silicon powder according to claim 1, characterized in that: The number of heat transfer holes (5) in each row is more than 4, and the heat transfer holes (5) are strip-shaped holes.
5. The energy-saving tunnel kiln for efficient drying of silicon powder according to claim 1, characterized in that: An induced draft fan is installed on the exhaust pipe (6), and a waste heat recovery device (18) is installed at the air outlet end of the exhaust pipe (6). The waste heat recovery device (18) is located above the kiln body (1), and an internal hollow air inlet box (19) and an air outlet box (20) are installed at intervals at both ends of the waste heat recovery device (18). A plurality of baffles (21) are installed in an up-and-down manner in the waste heat recovery device (18) between the air inlet box (19) and the air outlet box (20), and a plurality of waste heat recovery pipes (22) are arranged between the air inlet box (19) and the air outlet box (20) along the bending direction of the plurality of baffles (21). A circulation pipe (23) is installed on the waste heat recovery device (18) at the opposite end of the exhaust pipe (6), and a dehumidifier (27) is installed on the circulation pipe (23). Multiple drying layers (28) are arranged in the dehumidifier (27) along the air flow direction. The end of the circulation pipe (23) is connected to the air inlet box (19), and an air inlet pipe (24) is installed on the air outlet box (20). An air distribution pipe (25) is installed on the top of the kiln body (1), and the air inlet pipe (24) is connected to the air distribution pipe (25). The bottom of the air distribution pipe (25) is evenly distributed with multiple air jets at equal intervals along its length.
6. The energy-saving tunnel kiln for efficient drying of silicon powder according to claim 5, characterized in that: An air nozzle (26) is installed on the air jet port.
7. The energy-saving tunnel kiln for efficient drying of silicon powder according to claim 5, characterized in that: The drying layer (28) is made of activated carbon material.
8. The energy-saving tunnel kiln for efficient drying of silicon powder according to claim 1, characterized in that: A heat-insulating layer is provided on the inner wall of the kiln body (1).