Lithium iron phosphate sintering tail gas treatment device

Abstract

The utility model discloses a lithium iron phosphate sintering tail gas treatment device which comprises a kiln, a gas combustion assembly, a spray drying dust removal device, a heat pump and a nitrogen making machine, and the kiln is provided with a nitrogen inlet and a tail gas outlet; the gas combustion assembly is provided with a tail gas air inlet, a gas inlet and a hot air outlet. The tail gas air inlet communicates with the tail gas outlet and an air source. The spray drying dust removal device is communicated with the hot air outlet; the heat pump is communicated with the spray drying dust removal device; the nitrogen making machine is communicated with the heat pump, a nitrogen outlet of the nitrogen making machine is communicated with the nitrogen inlet, and a waste gas outlet of the nitrogen making machine is communicated with the tail gas air inlet; the high-temperature tail gas of the kiln can be conveyed to the gas combustion assembly, the tail gas after dust removal can be subjected to nitrogen recovery through the nitrogen making machine, the nitrogen making machine conveys the nitrogen and the waste gas to the kiln and the gas combustion assembly correspondingly, then the nitrogen and the waste gas are supplied to the kiln nitrogen and heat of the gas combustion assembly, and nitrogen energy consumption and gas consumption are reduced.

Description

Technical Field

[0001] This utility model relates to the field of lithium iron phosphate preparation technology, and in particular to a lithium iron phosphate combustion tail gas treatment device. Background Technology

[0002] In the production process of lithium iron phosphate, the cathode material for batteries, the lithium iron phosphate production process includes spray drying and high-temperature track kiln sintering. The exhaust gas from the high-temperature track kiln sintering is high-temperature and contains dust, tar, nitrogen, etc., and the exhaust gas after spray drying contains a large amount of nitrogen. Existing technologies do not recycle and utilize these exhaust gas components. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a lithium iron phosphate combustion tail gas treatment device.

[0004] A lithium iron phosphate sintering tail gas treatment device according to a first aspect embodiment of the present invention includes a kiln, a gas combustion assembly, a spray drying dust removal device, a heat pump, a nitrogen generator, and a drive assembly. The kiln has a receiving cavity and a nitrogen inlet and a tail gas outlet communicating with the receiving cavity, and the material can be contained in the receiving cavity and sintered. The gas combustion assembly has a tail gas air inlet, a fuel gas inlet, and a hot air outlet. The tail gas air inlet is connected to the tail gas outlet and an air source, and the air from the air source can enter the gas combustion assembly through the tail gas air inlet. The spray drying dust removal device has a hot air inlet, an air outlet, and a slurry inlet. The hot air inlet is connected to the hot air outlet; one end of the heat pump is connected to the air outlet; the nitrogen generator has an air inlet, a nitrogen outlet, and an exhaust gas outlet, the air inlet is connected to the other end of the heat pump, the nitrogen outlet is connected to the nitrogen inlet, and the exhaust gas outlet is connected to the tail gas air inlet; the drive assembly can drive the exhaust gas discharged from the tail gas outlet to pass sequentially through the gas combustion assembly, the spray drying dust removal device, the heat pump, and the nitrogen generator, and can drive the exhaust gas discharged from the exhaust gas outlet into the tail gas air inlet, and can drive the nitrogen discharged from the nitrogen outlet into the nitrogen inlet.

[0005] Furthermore, the spray drying dust removal device includes:

[0006] A spray drying tower, wherein the hot air inlet and the slurry inlet are respectively located at the top of the spray drying tower;

[0007] The first dust collector has an air outlet located on it. The first dust collector has an interface that is connected to the bottom of the spray drying tower.

[0008] The first buffer compartment is connected to the bottom of the first dust collector.

[0009] Furthermore, the lithium iron phosphate combustion tail gas treatment device also includes a high-temperature dehumidification device, which has an air inlet and an air outlet. The air inlet is connected to the air outlet, and the air outlet is connected to one end of the heat pump. The bottom of the high-temperature dehumidification device has a drain outlet, which is connected to a water recovery tank.

[0010] The drive assembly includes an exhaust fan, with its two ends connected to the air outlet and the air inlet, respectively. The exhaust fan can drive airflow from the air outlet to the air inlet.

[0011] Furthermore, the lithium iron phosphate combustion tail gas treatment device also includes:

[0012] A first exhaust pipe, one end of which is connected to the air outlet, and the other end of which is connected to the atmosphere, and a first valve is provided on the first exhaust pipe;

[0013] A first air passage pipe, one end of which is connected to the first exhaust pipe, the connection point of which is located between the first exhaust pipe end connected to the air outlet and the first valve, the other end of which is connected to the heat pump, and a second valve is provided on the first air passage pipe.

[0014] Furthermore, a second dust collector is connected between the exhaust outlet and the gas combustion assembly.

[0015] Furthermore, the lithium iron phosphate combustion tail gas treatment device also includes:

[0016] The second air passage pipe has one end connected to the second dust collector and the other end connected to the exhaust air inlet.

[0017] An air intake pipe, one end of which is connected to the air source, and the other end of which is connected to the second air passage pipe;

[0018] The third air passage pipe has one end connected to the exhaust gas outlet and the other end connected to the air intake pipe.

[0019] Furthermore, the lithium iron phosphate combustion tail gas treatment device also includes:

[0020] The second exhaust pipe has one end connected to the second air passage pipe and the other end connected to the atmosphere. A third valve is provided on the second exhaust pipe.

[0021] The fourth valve is located on the second air passage pipe. The connection between one end of the second exhaust pipe and the second air passage pipe is located between one end of the second air passage pipe connected to the second dust collector and the fourth valve. The connection between the air inlet pipe and the second air passage pipe is located between the fourth valve and the other end of the second air passage pipe connected to the exhaust air inlet.

[0022] The drive assembly further includes a blower, which is disposed on the air intake pipe and located between the other end of the third air passage pipe connected to the air intake pipe and the other end of the air intake pipe connected to the second air passage pipe. The blower drives the airflow to flow from the air intake pipe to the second air passage pipe.

[0023] Furthermore, a second buffer chamber is connected to the bottom of the second dust collector, and the kiln is provided with a material inlet, through which the dust in the second buffer chamber can be input into the kiln.

[0024] Furthermore, the gas combustion assembly includes a first hot air furnace and a second hot air furnace connected in sequence. The exhaust air inlet is located on the first hot air furnace, and the hot air outlet is located on the second hot air furnace. Both the first hot air furnace and the second hot air furnace are provided with the gas inlet.

[0025] Furthermore, a nitrogen storage tank is connected between the nitrogen outlet and the nitrogen inlet, a first precision filter is connected between the nitrogen outlet and the nitrogen storage tank, and a second precision filter is connected between the nitrogen storage tank and the nitrogen inlet.

[0026] The lithium iron phosphate sintering tail gas treatment device according to the embodiments of this utility model has at least the following technical effects: the high-temperature tail gas generated by kiln sintering can be transported to the gas combustion component, thereby using the high-temperature tail gas as a supplement to the heat of the gas combustion component; and the tail gas after dust removal by the spray drying dust removal device can be used to increase the waste heat through a heat pump and then recover nitrogen through a nitrogen generator. The nitrogen generator then transports the nitrogen and waste gas to the kiln and the gas combustion component respectively, thereby recovering the nitrogen in the dust removal tail gas as a supplement to the nitrogen in the kiln and using the waste gas heat of the nitrogen generator as a supplement to the heat of the gas combustion component, reducing the nitrogen energy consumption of the kiln and the natural gas consumption of the gas combustion component; by setting a high-temperature dehumidification device, the moisture in the tail gas can be recovered and used in other processes to reduce water consumption; by setting a second dust collector, the dust in the kiln can be recovered, so that the dust can be returned to the kiln or other processes for recycling.

[0027] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] Additional aspects and advantages of this invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0029] Figure 1 This is a schematic diagram of the lithium iron phosphate combustion tail gas treatment device according to the present invention.

[0030] Figure 2 A schematic diagram showing the connection between the high-temperature dehumidification device and the first exhaust pipe and the first air passage pipe;

[0031] Figure 3 A schematic diagram showing the connection between the second dust collector and the nitrogen generator and the first hot blast stove;

[0032] Figure 4 This is a schematic diagram showing the connection between the gas combustion assembly and the second dust collector and the spray drying tower.

[0033] Reference numerals: Kiln 100, Nitrogen Inlet 110, Exhaust Gas Outlet 120, Material Inlet 130, Gas Combustion Assembly 200, Exhaust Gas Air Inlet 210, Gas Inlet 220, Hot Air Outlet 230, First Hot Air Stove 240, Second Hot Air Stove 250, Spray Drying Dust Removal Device 300, Interface 301, Air Inlet 302, Air Outlet 303, Hot Air Inlet 310, Air Outlet 311, Slurry Inlet 312, Spray Drying Tower 320, First Dust Collector 330, First Buffer Chamber 331, Exhaust Fan 332, High Temperature Dehumidification Device 340, Drainage Outlet 341 350 water recovery tank, 400 heat pump, 410 first exhaust pipe, 411 first gas pipeline, 4121 first valve, 4122 second valve, 500 nitrogen generator, 510 air inlet, 520 nitrogen outlet, 530 exhaust outlet, 531 third gas pipeline, 600 second dust collector, 610 second gas pipeline, 620 air inlet pipe, 621 blower, 630 second exhaust pipe, 6311 third valve, 6312 fourth valve, 640 second buffer chamber, 700 nitrogen storage tank, 800 first precision filter, 900 second precision filter. Detailed Implementation

[0034] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0035] In the description of this utility model, the use of "first" and "second" is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features or the order of the technical features.

[0036] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0037] Reference Figure 1 As shown, the lithium iron phosphate sintering tail gas treatment device provided in the embodiment of this utility model includes a kiln 100, a gas combustion assembly 200, a spray drying dust removal device 300, a heat pump 400, a nitrogen generator 500, and a drive assembly. The kiln 100 has a receiving cavity and a nitrogen inlet 110 and a tail gas outlet 120 communicating with the receiving cavity, so that the material can be contained in the receiving cavity and sintered. The gas combustion assembly 200 has a tail gas air inlet 210, a fuel gas inlet 220, and a hot air outlet 230. The tail gas air inlet 210 is connected to the tail gas outlet 120 and an air source, and the air from the air source can enter the gas combustion assembly 200 through the tail gas air inlet 210. The spray drying dust removal device 300 has a hot air inlet 310, a gas outlet 311, and a slurry outlet. The material inlet 312 and the hot air inlet 310 are connected to the hot air outlet 230; one end of the heat pump 400 is connected to the air outlet 311; the nitrogen generator 500 has an air inlet 510, a nitrogen outlet 520 and an exhaust gas outlet 530, the air inlet 510 is connected to the other end of the heat pump 400, the nitrogen outlet 520 is connected to the nitrogen inlet 110, and the exhaust gas outlet 530 is connected to the exhaust air inlet 210; the drive assembly can drive the exhaust gas discharged from the exhaust gas outlet 120 to pass sequentially through the gas combustion assembly 200, the spray drying dust removal device 300, the heat pump 400 and the nitrogen generator 500, and can drive the exhaust gas discharged from the exhaust gas outlet 530 into the exhaust air inlet 210, and can drive the nitrogen discharged from the nitrogen outlet 520 into the nitrogen inlet 110.

[0038] Since the exhaust gas temperature of the kiln 100 is high and the exhaust gas contains dust, tar, nitrogen, etc., the kiln 100 can transport the high-temperature exhaust gas from sintering to the gas combustion component 200, thereby using the high-temperature exhaust gas as a supplement to the heat of the gas combustion component 200, thus reducing the fuel consumption of the gas combustion component 200. In addition, the tar can be burned in the gas combustion component 200 to generate heat value, which can reduce incomplete gas combustion and avoid the negative effects of tar adhesion.

[0039] The exhaust gas from the spray drying dust removal device 300 can be heated by the heat pump 400 and then used to recover nitrogen by the nitrogen generator 500. The nitrogen generator 500 then delivers the nitrogen to the kiln 100 and the exhaust gas to the gas combustion assembly 200. This allows the nitrogen in the exhaust gas to be used as a nitrogen supply for the kiln 100, and the heat from the exhaust gas of the nitrogen generator 500 to supplement the heat of the gas combustion assembly 200, thereby reducing the nitrogen energy consumption of the kiln 100 and the natural gas consumption of the gas combustion assembly 200.

[0040] Although the exhaust gas after dust removal has some heat, its temperature is not high. If the exhaust gas enters the gas combustion assembly 200 directly through the nitrogen generator 500 without being treated by the heat pump 400, it will increase the natural gas consumption of the gas combustion assembly 200. However, in this invention, the exhaust gas needs to pass through the heat pump 400 to raise its temperature before entering the nitrogen generator 500. Since the heat pump 400 has low power consumption and can increase the heat of the exhaust gas, it reduces the natural gas consumption of the gas combustion assembly 200, thus saving more energy compared to raising the temperature entirely through natural gas. Specifically, the production process of lithium iron phosphate includes sequential processes of feeding, batching, grinding, spray drying, sintering, and pulverizing.

[0041] like Figure 1As shown, during operation, an external nitrogen source introduces nitrogen into the kiln 100 through nitrogen inlet 110, and external materials enter the kiln 100 through material inlet 130. The kiln 100 sinters the materials using electric heating in a nitrogen environment. The sintered materials are directly discharged to the crushing device (not shown in the figure). The drive component causes the exhaust gas generated during sintering to be discharged through exhaust outlet 120 and enter the gas combustion component 200 through exhaust air inlet 210. At the same time, an external air source supplies air into the gas combustion component 200 through exhaust air inlet 210, exhaust gas discharged from the nitrogen generator 500 exhaust outlet 530 supplies exhaust gas into the gas combustion component 200 through exhaust air inlet 210, and external gas source supplies gas into the gas combustion component 200 through gas inlet 220. The gas combustion component 200 mixes and burns the internal gases, and the drive component causes the hot air after combustion to enter the spray drying dust removal device 300 through hot air outlet 230 and hot air inlet 310. The slurry (after sand milling) from the previous process in the spray drying dust removal device 300 enters the device through the slurry inlet 312. The device 300 dries the slurry and separates the dried powder from the gas. The separated gas, driven by the drive assembly, is discharged through the outlet 311 and enters the heat pump 400. The heat pump 400 increases the calorific value of the gas as needed before delivering it to the nitrogen generator 500. After extracting nitrogen, the nitrogen generator 500 discharges through the nitrogen outlet 520 and is transported to the kiln 100 for reuse, achieving nitrogen recovery, increasing the nitrogen recovery rate, and reducing nitrogen consumption in the kiln 100. Furthermore, the waste gas generated after nitrogen extraction by the nitrogen generator 500 is discharged through the waste gas outlet 530 and transported to the gas combustion assembly 200 to replenish heat. It is understandable that the material inlet 130 is not necessary. For example, the kiln 100 can be set up in the form of two rotating parts, and the opening and closing can be achieved by the relative rotation of the two parts of the kiln 100, thereby realizing the feeding.

[0042] Specifically, the nitrogen inlet 110 of the kiln 100 can be connected to an external nitrogen source, and can also be connected to the nitrogen outlet 520 of the nitrogen generator 500. The external nitrogen source can also replenish nitrogen into the kiln 100 through other inlets of the kiln 100.

[0043] Specifically, kiln 100 is a track kiln; however, other kiln structures may also be used to ensure the sintering of lithium iron phosphate.

[0044] Specifically, the gas can be natural gas or other gases suitable for the gas combustion assembly 200.

[0045] Specifically, heat pump 400 is a dry exhaust gas heat pump, but it can also be a heat pump of other structures, provided that it can dry the gas.

[0046] Specifically, the nitrogen generator 500 has an vent, through which the gas can be discharged into the atmosphere in an emergency.

[0047] Furthermore, such as Figure 1 As shown, the spray drying dust removal device 300 includes:

[0048] The spray drying tower 320 has a hot air inlet 310 and a slurry inlet 312 located at the top.

[0049] The first dust collector 330 has an air outlet 311 located on it. The first dust collector 330 has an interface 301, which is connected to the bottom of the spray drying tower 320.

[0050] The first buffer compartment 331 is connected to the bottom of the first dust collector 330.

[0051] The first buffer chamber 331 is provided to facilitate the collection of dry powder materials. The dry powder materials in the first buffer chamber 331 can be transported to the next process or to other processes in the production process that require dust.

[0052] During operation, the hot air after combustion enters the spray drying tower 320 through the hot air inlet 310, and the slurry enters the spray drying tower 320 through the slurry inlet 312. The hot air dries the slurry. The dried powder material and gas enter the first dust collector 330 through the interface 301. The first dust collector 330 separates them. The separated dry powder material falls to the bottom of the first dust collector 330 and enters the first buffer chamber 331 for collection. The separated gas is discharged through the gas outlet 311 and enters the heat pump 400, and then enters the nitrogen generator 500.

[0053] Specifically, the spray drying tower 320 includes a spray drying atomizer, which is used to atomize the slurry, making it easier for the slurry to be dried by hot air.

[0054] Specifically, the first dust collector 330 is a high-temperature resistant bag filter. While ensuring the separation of dry powder materials and high-temperature gas, the first dust collector 330 can also adopt other dust collector structures.

[0055] Specifically, the spray drying tower 320 and the first dust collector 330 are an integrated structure, with the spray drying tower 320 higher than the first dust collector 330. The interface 301 of the first dust collector 330 is directly connected to the bottom of the spray drying tower 320, allowing the material in the spray drying tower 320 to fall into the first dust collector 330 by gravity. Alternatively, the interface 301 of the first dust collector 330 may not be directly connected to the bottom of the spray drying tower 320, and the material in the spray drying tower 320 may be transported to the first dust collector 330 by a pump or other conveying method. Meanwhile, the gas in the spray drying tower 320 may enter the first dust collector 330 under the drive of the drive component. It is understood that, while ensuring spray drying capability, the spray drying tower 320 and the first dust collector 330 may also be configured as two separate parts.

[0056] Specifically, the first dust collector 330 can transport dry powder material to the first buffer bin 331 by gravity, or it can be transported to the first buffer bin 331 by power conveying (e.g., a pump).

[0057] Furthermore, such as Figure 1 , 2 As shown, the lithium iron phosphate combustion tail gas treatment device also includes a high-temperature dehumidification device 340. The high-temperature dehumidification device 340 has an air inlet 302 and an air outlet 303. The air inlet 302 is connected to the air outlet 311, and the air outlet 303 is connected to one end of the heat pump 400. The bottom of the high-temperature dehumidification device 340 has a drain outlet 341, and the drain outlet 341 is connected to a water recovery tank 350.

[0058] The drive assembly includes an exhaust fan 332, with its two ends connected to an air outlet 311 and an air inlet 302, respectively. The exhaust fan 332 can drive airflow from the air outlet 311 to the air inlet 302.

[0059] Since the gas coming out of the first dust collector 330 has a lot of moisture, a high-temperature dehumidification device 340 is installed to recover a large amount of moisture from the gas and store it in a water recovery tank 350. The water in the water recovery tank 350 can be used in the batching process, the sand milling process, or other processes that require water.

[0060] By installing an induced draft fan 332, the gas in the first dust collector 330 is drawn out by the induced draft fan 332, ensuring that the gas passes sequentially through the exhaust outlet 120, the gas combustion assembly 200, the spray drying tower 320, the first dust collector 330, the heat pump 400, and the nitrogen generator 500. It also ensures that the exhaust gas in the nitrogen generator 500 is transported to the gas combustion assembly 200, and that the nitrogen in the nitrogen generator 500 is transported to the nitrogen inlet 110.

[0061] During operation, the gas separated by the first dust collector 330 enters the high-temperature dehumidification device 340 through the air outlet 311 and the air inlet 302. The high-temperature dehumidification device 340 recovers a large amount of moisture from the gas and stores it in the recovery water tank 350. The dehumidified gas is discharged through the air outlet 303 and enters the heat pump 400, and then enters the nitrogen generator 500.

[0062] Specifically, the water in the recycling tank 350 can be transported to the batching process and the grinding process, or to other processes in the production process that require water.

[0063] Furthermore, such as Figure 1 , 2 As shown, the lithium iron phosphate combustion tail gas treatment device also includes:

[0064] The first exhaust pipe 410 has one end connected to the air outlet 303 and the other end connected to the atmosphere. A first valve 4121 is provided on the first exhaust pipe 410.

[0065] The first gas pipe 411 has one end connected to the first exhaust pipe 410. The connection between the first gas pipe 411 and the first exhaust pipe 410 is located between one end of the first exhaust pipe 410 connected to the air outlet 303 and the first valve 4121. The other end of the first gas pipe 411 is connected to one end of the heat pump 400. A second valve 4122 is provided on the first gas pipe 411.

[0066] By configuring a first exhaust pipe 410 and a first gas passage pipe 411, and by configuring a first valve 4121 and a second valve 4122, the flow direction of the gas discharged from the high-temperature dehumidification device 340 can be controlled by adjusting the first valve 4121 and the second valve 4122. This allows the gas to be directly discharged into the atmosphere or discharged into the first gas passage pipe 411. For example, in an emergency or when some equipment cannot work together due to maintenance, the first valve 4121 can be opened and the second valve 4122 closed to allow the gas to be directly discharged into the atmosphere. Alternatively, when the nitrogen content of the gas discharged from the high-temperature dehumidification device 340 is low and nitrogen recovery is not required, the first valve 4121 can also be opened and the second valve 4122 closed to allow the gas to be directly discharged into the atmosphere. When nitrogen recovery is required, the second valve 4122 can be opened and the first valve 4121 closed. Understandably, the first and second valves can be opened and closed simultaneously as needed, such as when the machine is stopped or when a specific process requires it.

[0067] Furthermore, such as Figure 1As shown, a second dust collector 600 is connected between the exhaust outlet 120 and the gas combustion assembly 200.

[0068] Since the exhaust gas from the kiln 100 includes dust, tar, nitrogen, etc., a second dust collector 600 is installed to filter impurities in the exhaust gas and recover the dust in the exhaust gas, so that the dust can be recycled.

[0069] Specifically, the second dust collector 600 is a high-temperature resistant dust collector with a bag filter. While ensuring that the dust in the exhaust gas can be recovered, the second dust collector 600 can also adopt other types of dust collectors.

[0070] Furthermore, such as Figure 3 As shown, the lithium iron phosphate combustion tail gas treatment device also includes:

[0071] The second air passage pipe 610 has one end connected to the second dust collector 600 and the other end connected to the exhaust air inlet 210.

[0072] An air intake pipe 620 is provided, with one end connected to an air source and the other end connected between one end of a second air passage pipe 610 and the other end of the second air passage pipe 610.

[0073] The third air passage pipe 531 has one end connected to the exhaust outlet 530 and the other end connected to the air intake pipe 620.

[0074] The exhaust outlet 530 is connected to the air inlet pipe 620 through the third air passage pipe 531 so that the air can be mixed with the exhaust gas from the nitrogen generator 500. Since a heat pump 400 is installed, the heat pump 400 can control the temperature of the gas entering the nitrogen generator 500, and thus control the temperature of the exhaust gas, thereby regulating the air temperature and reducing the electrical energy of the hot air.

[0075] Furthermore, such as Figure 3 As shown, the lithium iron phosphate combustion tail gas treatment device also includes:

[0076] The second exhaust pipe 630 has one end connected to the second air passage pipe 610 and the other end connected to the atmosphere. A third valve 6311 is provided on the second exhaust pipe 630.

[0077] The fourth valve 6312 is located on the second air passage 610. One end of the second exhaust pipe 630 is connected to the second air passage 610 between the second air passage 610, which is connected to the second dust collector 600, and the fourth valve 6312. The air inlet pipe 620 is connected to the second air passage 610 between the fourth valve 6312 and the other end of the second air passage 610, which is connected to the exhaust air inlet 210.

[0078] The drive assembly also includes a blower 621, which is mounted on the air intake pipe 620 and located between the other end of the third air passage pipe 531 connected to the air intake pipe 620 and the other end of the air intake pipe 620 connected to the second air passage pipe 610. The blower 621 drives the airflow from the air intake pipe 620 to the second air passage pipe 610.

[0079] By providing a second gas passage pipe 610 and a second exhaust pipe 630, and by providing a third valve 6311 and a fourth valve 6312, the gas coming out of the second dust collector 600 can be controlled to enter the gas combustion assembly 200 and / or be discharged into the atmosphere by adjusting the third valve 6311 and the fourth valve 6312.

[0080] Because it is equipped with a second exhaust pipe 630, a third valve 6311, and a fourth valve 6312, when the spray drying dust removal device 300 needs maintenance, the third valve 6311 is opened and the fourth valve 6312 is closed. The second exhaust pipe 630 can directly discharge the exhaust gas from the kiln 100 to the atmosphere, without affecting the independent use of the kiln 100, thus facilitating maintenance and repair of the spray drying process. It is understandable that the third and fourth valves can be flexibly adjusted according to the machine's status (stopped, started, etc.) and process requirements.

[0081] By setting up a blower 621, the mixing degree of the gas after the exhaust gas and air are mixed with the tail gas coming out of the second dust collector 600 can be adjusted by adjusting the frequency of the blower 621, thereby adjusting the concentration of the tail gas.

[0082] Furthermore, such as Figure 1 As shown, the bottom of the second dust collector 600 is connected to a second buffer chamber 640, and the kiln 100 is provided with a material inlet 130. The dust in the second buffer chamber 640 can be input into the kiln 100 through the material inlet 130.

[0083] The second buffer compartment 640 can store the recovered dust and allow the dust to be returned to the kiln 100.

[0084] Specifically, the bottom of the second buffer chamber 640 can also be connected to the crushing device, so that the crushing device can recycle the dust of the second dust collector 600, and the dust in the second buffer chamber 640 can also be transported to other processes in the production process that require dust.

[0085] Specifically, the second dust collector 600 can transport dust into the second buffer chamber 640 by gravity or by power transport (e.g., pumping).

[0086] Furthermore, such as Figure 4 As shown, the gas combustion assembly 200 includes a first hot blast stove 240 and a second hot blast stove 250 connected in sequence. An exhaust air inlet 210 is located on the first hot blast stove 240, and a hot air outlet 230 is located on the second hot blast stove 250. Both the first and second hot blast stoves 240 and 250 are equipped with gas inlets 220. Ignition devices may or may not be separately installed on the first and second hot blast stoves, depending on the type of hot blast stove.

[0087] The gas is burned sequentially through the first hot blast stove 240 and the second hot blast stove 250, so that the second hot blast stove 250 can burn the residual components (such as tar) in the exhaust gas of the first hot blast stove 240 more completely, and the second hot blast stove 250 can perform secondary combustion on the basis of the first hot blast stove 240 to ensure the gas temperature.

[0088] Specifically, both the first hot blast stove 240 and the second hot blast stove 250 are direct-fired hot blast stoves. However, other hot blast stove structures can also be used for the first hot blast stove 240 and the second hot blast stove 250, provided that the gas can be combusted.

[0089] Furthermore, such as Figure 1 As shown, a nitrogen storage tank 700 is connected between the nitrogen outlet 520 and the nitrogen inlet 110; a first precision filter 800 is connected between the nitrogen outlet 520 and the nitrogen storage tank 700; and a second precision filter 900 is connected between the nitrogen storage tank 700 and the nitrogen inlet 110.

[0090] A nitrogen storage tank 700 is provided to store nitrogen; a first precision filter 800 and a second precision filter 900 are provided to ensure the purity of the nitrogen entering the kiln 100.

[0091] In summary, the lithium iron phosphate combustion tail gas treatment unit operates as follows:

[0092] like Figure 1-4As shown, when the induced draft fan 332 and the blower 621 are started, nitrogen from the external nitrogen source and nitrogen in the nitrogen storage tank 700 are introduced into the kiln 100 through the nitrogen inlet 110. The material enters the kiln 100 through the material inlet 130. The kiln 100 sinters the material. The exhaust gas generated during sintering is discharged through the exhaust gas outlet 120 and enters the second dust collector 600. The second dust collector 600 filters the dust in the exhaust gas and transports the filtered dust to the second buffer bin 640. The second buffer bin 640 transports the dust to the material inlet 130 or the crushing device of the kiln 100 as needed. The filtered exhaust gas is transported to the first hot air furnace 240 through the second air passage pipe 610 and / or discharged into the air through the second exhaust pipe 630 as needed.

[0093] When the filtered exhaust gas is transported to the first hot air furnace 240 through the second gas pipeline 610, an external air source supplies air into the air inlet pipe 620. Exhaust gas discharged from the nitrogen generator 500's exhaust outlet 530 is also supplied into the air inlet pipe 620. The air and exhaust gas mix. Natural gas, as needed, enters the first hot air furnace 240 and / or the second hot air furnace 250 through the gas inlet 220. The first hot air furnace 240 mixes and burns the internal gases. The resulting hot air is then transported to the second hot air furnace 250 for further combustion. After combustion, the hot air is discharged through the hot air outlet 230 and then enters the spray drying tower 320 through the hot air inlet 310. The slurry enters the spray drying tower 320 through the slurry inlet 312. The slurry is dried by air. The dried powder material and gas enter the first dust collector 330 through interface 301. The first dust collector 330 separates the powder material. The separated powder material falls to the bottom of the first dust collector 330 and is stored in the first buffer bin 331. The powder material in the first buffer bin 331 can be transported to the kiln 100 or other suitable processes as needed. The separated gas enters the high-temperature dehumidification device 340 through the air outlet 311 and the air inlet 302. The high-temperature dehumidification device 340 recovers a large amount of moisture from the gas and stores it in the recovery water tank 350. The recovery water tank 350 can transport the water to the batching process and the sand milling process. The dehumidified gas can be transported to the first exhaust pipe 410 and / or the first gas pipeline 411 through the air outlet 303 according to the working conditions.

[0094] When the dehumidified gas is transported to the nitrogen generator 500 through the first gas pipeline 411, the dehumidified gas passes through the heat pump 400. The heat pump 400 increases the calorific value of the gas according to actual needs before transporting it to the nitrogen generator 500. The nitrogen generator 500 extracts nitrogen gas. The extracted nitrogen gas is filtered through the first precision filter 800 and then stored in the nitrogen storage tank 700. The nitrogen gas in the nitrogen storage tank 700 can be filtered through the second precision filter 900 and then transported to the kiln 100 for reuse. Meanwhile, the waste gas generated by the nitrogen generator 500 during extraction is transported to the air intake pipe 620 through the third gas pipeline 531.

[0095] Beneficial effects:

[0096] The high-temperature exhaust gas generated by sintering in the kiln 100 can be transported to the gas combustion assembly 200, thereby supplementing the heat of the gas combustion assembly 200. The exhaust gas after dust removal by the spray drying dust removal device 300 can be heated by the heat pump 400 and then used to recover nitrogen through the nitrogen generator 500. The nitrogen generator 500 then transports the nitrogen and exhaust gas to the kiln 100 and the gas combustion assembly 200 respectively, thereby recovering the nitrogen from the dust-removed exhaust gas as nitrogen replenishment for the kiln 100, and using the nitrogen from the nitrogen generator 500... The heat from the exhaust gas supplements the heat of the gas combustion component 200, reducing the nitrogen energy consumption of the kiln 100 and the natural gas consumption of the first hot blast stove 240 and the second hot blast stove 250. By installing a high-temperature dehumidification device 340, the moisture in the exhaust gas is recovered and can be returned to the batching and grinding processes, reducing the water consumption in the batching and grinding processes. By installing a second dust collector 600, the dust in the kiln 100 is recovered, allowing the dust to be returned to the kiln 100 or the crushing device for recycling.

[0097] In the description of this specification, references to terms such as "some embodiments" or "as one might imagine" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0098] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A lithium iron phosphate sintering tail gas treatment device, characterized in that, The application relates to a lithium iron phosphate sintering tail gas treatment device. The device comprises: a kiln (100) having a containing cavity and a nitrogen inlet (110) and a tail gas outlet (120) communicating with the containing cavity, material being capable of being contained in the containing cavity and being sintered; a gas combustion assembly (200) having a tail gas air inlet (210), a gas inlet (220) and a hot air outlet (230), the tail gas air inlet (210) communicating with the tail gas outlet (120) and an air source, air of the air source being capable of entering the gas combustion assembly (200) through the tail gas air inlet (210); a spray drying dust removal device (300) having a hot air inlet (310), an air outlet (311) and a slurry inlet (312), the hot air inlet (310) communicating with the hot air outlet (230); a heat pump (400), one end of the heat pump (400) communicating with the air outlet (311); a nitrogen generator (500) having an air inlet (510), a nitrogen outlet (520) and a waste gas outlet (530), the air inlet (510) communicating with the other end of the heat pump (400), the nitrogen outlet (520) communicating with the nitrogen inlet (110), and the waste gas outlet (530) communicating with the tail gas air inlet (210); 2. The lithium iron phosphate sintering tail gas treatment device according to claim 1, characterized in that: a driving assembly capable of driving tail gas discharged from the tail gas outlet (120) to pass through the gas combustion assembly (200), the spray drying dust removal device (300), the heat pump (400) and the nitrogen generator (500) in sequence, and capable of driving waste gas discharged from the waste gas outlet (530) to enter the tail gas air inlet (210), and capable of driving nitrogen discharged from the nitrogen outlet (520) to enter the nitrogen inlet (110). The spray drying dust removal device (300) comprises: a spray drying tower (320), the hot air inlet (310) and the slurry inlet (312) being arranged at the top of the spray drying tower (320) respectively; a first dust remover (330), the air outlet (311) being arranged on the first dust remover (330), the first dust remover (330) having an interface (301) communicating with the bottom of the spray drying tower (320); a first buffer bin (331) communicating with the bottom of the first dust remover (330).

3. The lithium iron phosphate sintering tail gas treatment device according to claim 1, further comprising a high-temperature dehumidification device (340) having an air inlet (302) and an air outlet (303), the air inlet (302) communicating with the air outlet (311), the air outlet (303) communicating with one end of the heat pump (400), the high-temperature dehumidification device (340) having a drain (341) at the bottom, and a recovered water tank (350) being connected to the drain (341). The driving assembly comprises an air induction fan (332) in communication with the air outlet (311) and the air inlet (302) respectively, and the air induction fan (332) can drive the airflow to flow from the air outlet (311) to the air inlet (302).

4. The lithium iron phosphate sintering off-gas treatment device according to claim 3, characterized in that: Further comprising: A first exhaust pipe (410) is connected with the air outlet (303) at one end, and is in communication with the atmosphere at the other end, and a first valve (4121) is arranged on the first exhaust pipe (410); A first gas path pipeline (411) is connected at one end on the first exhaust pipe (410), and the connection between the first gas path pipeline (411) and the first exhaust pipe (410) is located between the one end of the first exhaust pipe (410) connected with the air outlet (303) and the first valve (4121), and the other end of the first gas path pipeline (411) is connected with one end of the heat pump (400), and a second valve (4122) is arranged on the first gas path pipeline (411).

5. The lithium iron phosphate sintering off-gas treatment device according to claim 1 or 3, characterized in that: The tail gas outlet (120) and the gas combustion assembly (200) are connected with a second dust remover (600).

6. The lithium iron phosphate sintering off-gas treatment device according to claim 5, characterized in that: Further comprising: A second gas path pipeline (610) is in communication with the second dust remover (600) at one end, and is in communication with the tail gas air inlet (210) at the other end; An air inlet pipe (620) is in communication with the air source at one end, and is connected on the second gas path pipeline (610) at the other end; A third gas path pipeline (531) is in communication with the exhaust gas outlet (530) at one end, and is connected on the air inlet pipe (620) at the other end.

7. The lithium iron phosphate sintering off-gas treatment device according to claim 6, characterized in that: Further comprising: A second exhaust pipe (630) is in communication with the second gas path pipeline (610) at one end, and is in communication with the atmosphere at the other end, and a third valve (6311) is arranged on the second exhaust pipe (630); A fourth valve (6312) is arranged on the second gas path pipeline (610), and the one end of the second exhaust pipe (630) is connected with the second gas path pipeline (610) between the one end of the second gas path pipeline (610) in communication with the second dust remover (600) and the fourth valve (6312), and the connection between the air inlet pipe (620) and the second gas path pipeline (610) is located between the fourth valve (6312) and the other end of the second gas path pipeline (610) in communication with the tail gas air inlet (210); The driving assembly further comprises a blower (621) arranged on the air inlet pipe (620) and located between the other end of the third air path pipeline (531) connected with the air inlet pipe (620) and the other end of the air inlet pipe (620) connected with the second air path pipeline (610), and the blower (621) drives the airflow to flow from the air inlet pipe (620) to the second air path pipeline (610).

8. The lithium iron phosphate sintering off-gas treatment device according to claim 5, characterized in that: The bottom of the second dust collector (600) is connected with a second buffer bin (640), the kiln (100) is provided with a material inlet (130), and the dust in the second buffer bin (640) can be input into the kiln (100) through the material inlet (130).

9. The lithium iron phosphate sintering off-gas treatment device according to claim 1, characterized in that: The gas combustion assembly (200) comprises a first hot blast furnace (240) and a second hot blast furnace (250) connected in sequence, the tail gas air inlet (210) is arranged on the first hot blast furnace (240), the hot blast outlet (230) is arranged on the second hot blast furnace (250), and the first hot blast furnace (240) and the second hot blast furnace (250) are both provided with the gas inlet (220).

10. The lithium iron phosphate sintering off-gas treatment device according to claim 1, characterized in that: The nitrogen outlet (520) is connected with a nitrogen storage tank (700) between the nitrogen inlet (110), the nitrogen outlet (520) is connected with a first precision filter (800) between the nitrogen storage tank (700), and the nitrogen storage tank (700) and the nitrogen inlet (110) are connected with a second precision filter (900).

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