Rotary kiln system for calcining iron phosphate

Abstract

The utility model discloses a rotary kiln system for calcining iron phosphate. The rotary kiln system comprises a kiln, a flue gas heat exchange device, a waste gas heat exchange device, a vibration device and a dust remover, an inner cavity of the kiln is provided with a material end and a gas end, the material end is provided with a waste gas port, and the gas end is provided with a flue gas port; the flue gas heat exchange device is connected to the flue gas port; the waste gas heat exchange device comprises a shell and a heat exchange vertical pipe, the shell is provided with a fresh air opening and an air outlet, the air outlet communicates with an inner cavity of the kiln, the heat exchange vertical pipe is arranged in the shell, and the lower end communicates with the waste gas opening. The vibration device is in transmission connection with the heat exchange vertical pipe and used for vibrating the heat exchange vertical pipe. An inlet of the dust remover is connected with the upper end of the heat exchange vertical pipe and provided with a dust collecting bin. According to the scheme, iron phosphate dust on the inner wall of the heat exchange vertical pipe can be vibrated and removed by means of the vibration device, and the vibrated and removed iron phosphate dust directly returns to the kiln under the action of self weight, so that the heat exchange pipeline is effectively prevented from being blocked, meanwhile, waste heat recovery of smoke and waste gas is achieved, the utilization rate of dust materials is increased, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of iron phosphate calcining equipment, in particular to a rotary kiln system for calcining iron phosphate. Background Art

[0002] Iron phosphate is the main precursor for producing lithium iron phosphate cathode materials. During the production process, iron phosphate dihydrate needs to be calcined at high temperature and then prepared into anhydrous iron phosphate. The calcination equipment is generally a rotary kiln, which is heated by natural gas combustion, and the calcination temperature is 600-800℃.

[0003] For example, patent CN220728882U discloses a rotary kiln for the production of iron phosphate, which can support and limit the first rotary drum and the second rotary drum through the action of limiting mechanisms such as a limiting frame and a supporting ring, and when the first rotary drum rotates, it can crush the agglomerated iron phosphate through rotating covers such as a crushing plate to facilitate subsequent drying.

[0004] However, the rotary kiln will produce two high-temperature exhaust gases during the production process. One is the high-temperature flue gas produced by the combustion of natural gas in the furnace, and the other is the high-temperature waste gas produced by the calcination of materials in the furnace. The waste gas produced by the calcination of materials in the furnace carries a large amount of fine particles, which is very easy to clog the heat exchanger. There is currently a lack of effective means to recover this part of the waste heat. Utility Model Content

[0005] The purpose of the utility model is to overcome the above technical deficiencies and propose a rotary kiln system for calcining iron phosphate, so as to solve the technical problem that the waste gas generated by the calcination of materials in the rotary kiln in the prior art is very easy to clog the heat exchanger due to the large amount of fine particles, and there is currently a lack of effective means to recover this part of the waste heat.

[0006] In order to achieve the above technical purpose, the utility model adopts the following technical solutions:

[0007] The utility model provides a rotary kiln system for calcining iron phosphate, comprising:

[0008] A kiln, wherein the inner cavity of the kiln has a material end and a gas end, the material end is provided with an exhaust gas outlet, and the gas end is provided with a smoke outlet;

[0009] A flue gas heat exchange device connected to the flue gas outlet;

[0010] The exhaust gas heat exchange device comprises a shell and a heat exchange vertical pipe, wherein the shell is provided with a fresh air inlet and an air outlet, the air outlet is connected to the inner cavity of the kiln, and the heat exchange vertical pipe is arranged in the shell, and the lower end thereof is connected to the exhaust gas outlet;

[0011] a vibration device, drivingly connected to the heat exchange vertical pipe, and used for vibrating the heat exchange vertical pipe; and

[0012] The dust collector has an inlet connected to the upper end of the heat exchange vertical pipe and is provided with a dust collecting bin.

[0013] In some embodiments, the heat exchange vertical pipes are provided in plurality, and the vibrating device is a vibrating hammer, which is provided on the outer wall of the outer shell and is used to vibrate the outer shell so that each of the heat exchange vertical pipes can vibrate synchronously.

[0014] In some embodiments, an intake pipe is connected between the heat exchange vertical pipe and the exhaust port, and an exhaust pipe is connected between the heat exchange vertical pipe and the dust collector. The exhaust gas heat exchange device also includes an intake temperature sensor and an exhaust temperature sensor. The intake temperature sensor is arranged on the intake pipe, and the exhaust temperature sensor is arranged on the exhaust pipe.

[0015] In some embodiments, the exhaust pipe is provided with a cold air supply valve; and / or,

[0016] The exhaust gas heat exchange device further includes a pressure difference sensor, which is used to monitor the pressure difference between the intake pipe and the exhaust pipe.

[0017] In some embodiments, the dust collector includes a bag dust collector box and an induced draft fan, the bag dust collector box is arranged at the upper end of the dust collecting bin and is connected to the dust collecting bin, and the induced draft fan is connected to the exhaust port of the bag dust collector box;

[0018] Wherein, the dust collecting bin is connected to the heat exchange vertical pipe.

[0019] In some embodiments, the rotary kiln system for calcining iron phosphate further includes a storage bin, which is respectively connected to the material end and the dust collecting bin, and is used to transport materials to the material end and to recover materials transported by the dust collecting bin.

[0020] In some embodiments, the rotary kiln system for calcining iron phosphate further includes a feeding screw mechanism, which is disposed between the storage bin and the material end and is used to transport the material in the storage bin to the material end.

[0021] In some embodiments, the exhaust gas heat exchange device further includes a fresh air filter, a fresh air blower and a fresh air duct, and the fresh air filter, the fresh air blower, the fresh air duct and the fresh air outlet are connected in sequence.

[0022] In some embodiments, the outer periphery of the heat exchange riser is provided with spiral heat exchange fins along its axial direction.

[0023] In some embodiments, the rotary kiln system for calcining iron phosphate further comprises a gas pipe and a mixing bin, wherein the gas pipe is used to transport gas and is sequentially connected to the mixing bin and the gas end;

[0024] The exhaust gas heat exchange device also includes an air outlet duct connected to the air outlet, and the air outlet duct is connected to the mixing chamber.

[0025] Compared with the prior art, in the rotary kiln system for calcining iron phosphate provided by the utility model, the relatively pure high-temperature flue gas generated by the combustion of natural gas at the gas end is discharged from the flue gas outlet to the flue gas heat exchange device for heat exchange. The high-temperature exhaust gas generated when the material in the kiln is calcined at the material end is transported to the heat exchange vertical pipe through the exhaust gas outlet to exchange heat with the fresh air in the shell, and the heated fresh air is then returned to the kiln from the air outlet of the shell to play a combustion-supporting role; at the same time, the exhaust gas after cooling in the heat exchange vertical pipe enters the dust collector to remove the iron phosphate dust in the exhaust gas before being discharged into the atmosphere, and the dust collecting bin collects the iron phosphate dust to recover the iron phosphate material. In addition, the vibration device can vibrate off the iron phosphate dust adsorbed on the inner wall of the heat exchange vertical pipe during the heat exchange process, and the iron phosphate dust after vibration is directly returned to the kiln under the action of its own weight, so as to effectively avoid the blockage of the heat exchange pipeline, and at the same time realize the waste heat recovery of the flue gas and the exhaust gas, and improve the utilization rate of the dust material and reduce the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a partial structural schematic diagram of a rotary kiln system for calcining iron phosphate provided in an embodiment of the utility model;

[0027] Figure 2 yes Figure 1 A partial schematic diagram of the middle kiln;

[0028] Figure 3 yes Figure 1 Schematic diagram of the structure of the exhaust gas heat exchange device and the vibration device.

[0029] Description of reference numerals:

[0030] 1. Kiln; 11. Material end; 11a. Exhaust outlet; 12. Gas end; 12a. Smoke outlet; 2. Exhaust heat exchange device; 21. Shell; 21a. Fresh air inlet; 21b. Air outlet; 22. Heat exchange vertical pipe; 23. Inlet pipe; 24. Exhaust pipe; 25. Inlet temperature sensor; 26. Exhaust temperature sensor; 27. Cold air supply valve; 28. Pressure difference sensor; 29. ​​Fresh air filter; 291. Fresh air blower; 292. Fresh air duct; 293. Exhaust duct; 3. Vibration device; 4. Dust collector; 41. Dust collection bin; 42. Bag dust removal box; 43. Draft fan; 44. Rotary valve; 5. Storage bin; 6. Feeding screw mechanism; 7. Gas pipe; 8. Mixing bin. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0032] In order to solve the technical problem that the waste gas generated by the calcination of materials in the rotary kiln in the prior art is very easy to clog the heat exchanger due to the large amount of fine particles, and there is currently a lack of effective means to recover this part of the waste heat, the utility model provides a rotary kiln system for calcining iron phosphate, which can effectively avoid the blockage of the heat exchange pipeline, and at the same time realize the waste heat recovery of flue gas and waste gas, and improve the utilization rate of dust materials and reduce costs.

[0033] See also Figure 1 and Figure 2 , Figure 1 and Figure 2 The utility model is a schematic structural diagram of a rotary kiln system for calcining iron phosphate in an embodiment of the utility model, wherein the rotary kiln system for calcining iron phosphate comprises a kiln 1, a flue gas heat exchange device, an exhaust gas heat exchange device 2, a vibration device 3 and a dust collector 4; the inner cavity of the kiln 1 has a material end 11 and a gas end 12, the material end 11 is provided with an exhaust gas port 11a, and the gas end 12 is provided with a flue gas port 12a; the flue gas heat exchange device is connected to the flue gas port 12a; the exhaust gas heat exchange device 2 comprises an outer shell 21 and a heat exchange vertical pipe 22, the outer shell 21 is provided with a fresh air port 21a and an air outlet 21b, the air outlet 21b is connected to the inner cavity of the kiln 1, the heat exchange vertical pipe 22 is arranged in the outer shell 21, and the lower end is connected to the exhaust gas port 11a; the vibration device 3 is transmission-connected to the heat exchange vertical pipe 22 for vibrating the heat exchange vertical pipe 22; the inlet of the dust collector 4 is connected to the upper end of the heat exchange vertical pipe 22, and a dust collecting bin 41 is provided.

[0034] In the rotary kiln system for calcining iron phosphate provided by the utility model, relatively pure high-temperature flue gas generated by the combustion of natural gas at the gas end 12 is discharged from the flue gas outlet 12a to the flue gas heat exchange device for heat exchange. The high-temperature waste gas generated when the material in the kiln 1 is calcined at the material end 11 is transported to the heat exchange vertical pipe 22 through the waste gas outlet 11a to exchange heat with the fresh air in the shell 21, and the heated fresh air is then returned to the kiln 1 from the air outlet 21b of the shell 21 to play a role in combustion; at the same time, the waste gas after cooling in the heat exchange vertical pipe 22 enters the dust collector 4 to remove the iron phosphate dust in the waste gas before being discharged into the atmosphere, and the dust collecting bin 41 collects the iron phosphate dust to recover the iron phosphate material. In addition, the vibration device 3 can vibrate off the iron phosphate dust adsorbed on the inner wall of the heat exchange vertical pipe 22 during the heat exchange process. The iron phosphate dust after vibration returns directly to the kiln 1 under the action of its own weight, so as to effectively avoid the blockage of the heat exchange pipeline, and at the same time realize the waste heat recovery of the flue gas and exhaust gas, and improve the utilization rate of dust materials and reduce costs.

[0035] It should be noted that the specific structure of the flue gas heat exchange device is not limited as long as it can realize the recovery of waste heat from the flue gas. It can be the same structure as the exhaust gas heat exchange device 2, or it can be a simple heat exchanger with flue gas flow channels and steam flow channels to use the waste heat for the boiler, or it can be other structures.

[0036] In one embodiment, see Figure 3 The heat exchange vertical pipes 22 are provided with a plurality of vibrating devices 3, which are vibrating hammers. The vibrating hammers are provided on the outer wall of the shell 21, and are used to vibrate the shell 21, so that each heat exchange vertical pipe 22 can vibrate synchronously.

[0037] In this embodiment, a plurality of heat exchange vertical pipes 22 are provided to improve the heat exchange efficiency between fresh air and exhaust gas, and at the same time, a vibrator is provided on the outer wall of the outer shell 21 to synchronously drive the vibration of the plurality of heat exchange vertical pipes 22, and effectively shake off the iron phosphate dust on the inner wall surfaces of the plurality of heat exchange vertical pipes 22; at the same time, the distance between the heat exchange vertical pipe 22 and the vibrator is increased to reduce the adverse effect of high temperature on the vibrator. It should be noted that in this scheme, a plurality of vibrators are provided, and the plurality of vibrators are arranged at intervals along the circumference of the outer shell 21, and the materials adhered to the heat exchange vertical pipe 22 can be shaken off by the regular vibration of the vibrator. And spiral heat exchange fins are provided on the outer periphery of each heat exchange vertical pipe 22 along its axial direction to improve the heat exchange capacity. The specific structure and principle of the vibrator are prior art and will not be elaborated here.

[0038] In one embodiment, an intake pipe 23 is connected between the heat exchange vertical pipe 22 and the exhaust port 11a, and an exhaust pipe 24 is connected between the heat exchange vertical pipe 22 and the dust collector 4. The exhaust gas heat exchange device 2 also includes an intake temperature sensor 25 and an exhaust temperature sensor 26. The intake temperature sensor 25 is arranged on the intake pipe 23, and the exhaust temperature sensor 26 is arranged on the exhaust pipe 24.

[0039] In this embodiment, temperature sensors are respectively provided at the inlet and outlet of the heat exchange vertical pipe 22 to monitor the temperature of the high-temperature exhaust gas before and after the heat exchange, so as to prevent the exhaust gas entering the dust collector 4 from being too hot and damaging the dust collector 4. At the same time, the exhaust pipe 24 is provided with a cold air supply valve 27; the exhaust gas heat exchange device 2 also includes a pressure difference sensor 28, which is used to monitor the pressure difference between the intake pipe 23 and the exhaust pipe 24. In this way, the pressure difference at the inlet and outlet of the heat exchange vertical pipe 22 can be monitored with the help of the pressure difference sensor 28 to assist in determining whether the heat exchange vertical pipe 22 is blocked. In addition, a cold air supply valve 27 is provided to control its opening through a temperature sensor to avoid excessively high temperatures entering the dust collector 4.

[0040] In one embodiment, the dust collector 4 includes a bag dust collector box 42 and an induced draft fan 43. The bag dust collector box 42 is arranged at the upper end of the dust collecting bin 41 and is connected to the dust collecting bin 41. The induced draft fan 43 is connected to the exhaust port of the bag dust collector box 42; wherein the dust collecting bin 41 is connected to the heat exchange vertical pipe 22.

[0041] In this embodiment, the dust collector 4 is configured to be a bag dust collector, and the dust removal efficiency is improved by the induced draft fan 43. At the same time, the dust isolated by the bag dust collector is collected in the dust collecting bin 41, and the structure is stable and reliable.

[0042] In one embodiment, the rotary kiln system for calcining iron phosphate further includes a storage bin 5, which is connected to the material end 11 and the dust collecting bin 41 respectively, and is used to transport the material to the material end 11 and to recover the material transported by the dust collecting bin 41.

[0043] In this embodiment, a storage bin 5 is provided to transfer the materials entering the kiln 1, and at the same time, the dust in the dust collecting bin 41 can be stored to ensure that the dust collector 4 can continuously and stably remove dust. It should be noted that in this solution, the dust collecting bin 41 is located above the storage bin 5, and a rotary valve 44 is provided on the connecting pipe between the two. In addition, the rotary kiln system for calcining iron phosphate also includes a feeding screw mechanism 6, which is provided between the storage bin 5 and the material end 11, and is used to transport the material in the storage bin 5 to the material end 11. A feed valve is provided between the feeding screw mechanism 6 and the material end 11 of the kiln 1. The specific structure and form of the feeding screw mechanism 6 are prior art and will not be elaborated here.

[0044] In one embodiment, the exhaust gas heat exchange device 2 further includes a fresh air filter 29, a fresh air blower 291 and a fresh air duct 292, and the fresh air filter 29, the fresh air blower 291, the fresh air duct 292 and the fresh air port 21a are connected in sequence.

[0045] In this embodiment, a fresh air filter 29 and a fresh air blower 291 are provided to improve the fresh air delivery efficiency while purifying the fresh air.

[0046] In one embodiment, the rotary kiln system for calcining iron phosphate also includes a gas pipe 7 and a mixing bin 8, the gas pipe 7 is used to transport gas and is connected to the mixing bin 8 and the gas end 12 in sequence; the exhaust gas heat exchange device 2 also includes an air outlet duct 293 connected to the air outlet 21b, and the air outlet duct 293 is connected to the mixing bin 8.

[0047] In this embodiment, the fresh air and natural gas after heat exchange are mixed in the mixing chamber 8 and then transported to the combustion end for combustion, so that the fresh air preheats the natural gas and the fresh air and natural gas are transported to the combustion end in a suitable ratio to improve the combustion efficiency. It should be noted that in this solution, the mixing chamber 8 is provided with multiple branches, and the gas pipe 7 and the air outlet pipe 293 are respectively provided with multiple branches corresponding to the mixing chamber 8.

[0048] In order to better understand the present invention, the following Figures 1 to 3 The technical solution of the utility model is described in detail:

[0049] The iron phosphate dihydrate material enters the storage bin 5 through the pipeline, and then enters the rotary kiln through the feeding screw mechanism 6. The kiln 1 produces two exhaust gases during calcination, of which the clean high-temperature flue gas generated by the combustion of natural gas is discharged from the flue gas port 12a, and the waste heat is recovered through the flue gas heat exchange device. The high-temperature exhaust gas in the furnace carrying a large amount of dust enters the finned heat exchange vertical pipe 22 from the exhaust port 11a, and enters the exhaust pipe 24 and the bag-type dust collector 4 in turn after heat exchange and cooling through the heat exchange vertical pipe 22, and then is discharged from the system through the induced draft fan 43. The dust collected by the dust collector 4 returns to the storage bin 5 through the rotary valve 44 and the connecting pipe to recover the iron phosphate dust.

[0050] The inlet and outlet of the heat exchange vertical pipe 22 are respectively provided with temperature sensors to monitor the temperature of the high-temperature exhaust gas before and after the heat exchange. In addition, a pressure difference sensor 28 is configured to monitor the pressure difference between the inlet and outlet of the heat exchange vertical pipe 22 to assist in determining whether the heat exchanger is blocked. At the same time, in order to prevent the exhaust gas entering the dust collector 4 from being too hot and damaging the bag, a cold air replenishment valve 27 is provided, and its opening is associated with the temperature sensor.

[0051] The heat exchange vertical pipe 22 is installed vertically and is installed above the furnace head of the kiln 1. The high-temperature exhaust gas in the furnace passes through the heat exchange vertical pipe 22, and the fresh air passes through the fresh air filter 29, the fresh air blower 291, the fresh air duct 292 and the fresh air port 21a in sequence into the shell 21 to exchange heat with the heat exchange vertical pipe 22. A vibrating hammer is installed on the outer wall of the shell 21, and the material adhering to the heat exchange vertical pipe 22 can be made to fall back into the kiln 1 through vibration to prevent the heat exchange vertical pipe 22 from being blocked.

[0052] The temperature of the fresh air will increase significantly after the heat exchange with the exhaust gas. The fresh air is heated and mixed with the natural gas in the gas pipe 7, and then burned in the furnace to heat the kiln 1, thereby realizing the recovery and utilization of the waste heat of the exhaust gas in the furnace.

[0053] The specific implementation methods of the utility model described above do not constitute a limitation on the protection scope of the utility model. Any other corresponding changes and modifications made according to the technical concept of the utility model should be included in the protection scope of the claims of the utility model.

Claims

1. A rotary kiln system for calcining iron phosphate, characterized in that: include: A kiln, wherein the inner cavity of the kiln has a material end and a gas end, the material end is provided with an exhaust gas outlet, and the gas end is provided with a smoke outlet; A flue gas heat exchange device connected to the flue gas outlet; The exhaust gas heat exchange device comprises a shell and a heat exchange vertical pipe, wherein the shell is provided with a fresh air inlet and an air outlet, the air outlet is connected to the inner cavity of the kiln, and the heat exchange vertical pipe is arranged in the shell, and the lower end thereof is connected to the exhaust gas outlet; a vibration device, drivingly connected to the heat exchange vertical pipe, and used for vibrating the heat exchange vertical pipe; and The dust collector has an inlet connected to the upper end of the heat exchange vertical pipe and is provided with a dust collecting bin.

2. The rotary kiln system for calcining iron phosphate according to claim 1, characterized in that: There are a plurality of heat exchange vertical pipes, and the vibrating device is a vibrating hammer, which is arranged on the outer wall of the shell and is used to vibrate the shell so that each of the heat exchange vertical pipes can vibrate synchronously.

3. The rotary kiln system for calcining iron phosphate according to claim 1, characterized in that: An intake pipe is connected between the heat exchange vertical pipe and the exhaust port, and an exhaust pipe is connected between the heat exchange vertical pipe and the dust collector. The exhaust gas heat exchange device also includes an intake temperature sensor and an exhaust temperature sensor. The intake temperature sensor is arranged on the intake pipe, and the exhaust temperature sensor is arranged on the exhaust pipe.

4. The rotary kiln system for calcining iron phosphate according to claim 3, characterized in that: The exhaust pipe is provided with a cold air supply valve; and / or, The exhaust gas heat exchange device further includes a pressure difference sensor, which is used to monitor the pressure difference between the intake pipe and the exhaust pipe.

5. The rotary kiln system for calcining iron phosphate according to claim 1, characterized in that: The dust collector comprises a bag dust collector box and an induced draft fan, wherein the bag dust collector box is arranged at the upper end of the dust collecting bin and is connected to the dust collecting bin, and the induced draft fan is connected to the exhaust port of the bag dust collector box; Wherein, the dust collecting bin is connected to the heat exchange vertical pipe.

6. The rotary kiln system for calcining iron phosphate according to claim 1, characterized in that: The rotary kiln system for calcining iron phosphate also includes a storage bin, which is connected to the material end and the dust collecting bin respectively, and is used to transport materials to the material end and can recover the materials transported by the dust collecting bin.

7. The rotary kiln system for calcining iron phosphate according to claim 6, characterized in that: The rotary kiln system for calcining iron phosphate further comprises a feeding screw mechanism, which is disposed between the storage bin and the material end and is used for conveying the material in the storage bin to the material end.

8. The rotary kiln system for calcining iron phosphate according to claim 1, characterized in that: The exhaust gas heat exchange device also includes a fresh air filter, a fresh air blower and a fresh air duct, and the fresh air filter, the fresh air blower, the fresh air duct and the fresh air outlet are connected in sequence.

9. The rotary kiln system for calcining iron phosphate according to claim 1, characterized in that: The outer periphery of the heat exchange vertical pipe is provided with spiral heat exchange fins along its axial direction.

10. The rotary kiln system for calcining iron phosphate according to claim 1, characterized in that: The rotary kiln system for calcining iron phosphate further comprises a gas pipe and a mixing bin, wherein the gas pipe is used to transport gas and is sequentially connected with the mixing bin and the gas end; The exhaust gas heat exchange device also includes an air outlet duct connected to the air outlet, and the air outlet duct is connected to the mixing chamber.

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