High-temperature oxygen separation system of lithium battery positive electrode material sintering roller kiln

Abstract

The utility model belongs to the technical field of lithium battery positive electrode material production, and discloses a lithium battery positive electrode material sintering roller kiln high-temperature oxygen separation system which is characterized in that a plurality of roller kilns are connected in parallel, each roller kiln is provided with a coarse dust remover, each coarse dust remover is provided with a high-temperature waste heat recovery device, each high-temperature waste heat recovery device is provided with a fine dust remover, and the fine dust remover is provided with a high-temperature oxygen separation device. A low-temperature waste heat recovery device is mounted on the fine dust remover, a variable-frequency centrifugal fan is mounted on the low-temperature waste heat recovery device, and a storage tank I is mounted at an outlet of the variable-frequency centrifugal fan; the storage tanks I are connected in parallel and then connected with an oxygen separation system, and a set of oxygen separation system is adopted for dust removal and oxygen recovery of multiple roller kilns; the high-temperature waste heat recovery device and the low-temperature waste heat recovery device are tubular cold water heat exchangers; and a sound wave nitrogen ash remover is arranged on the high-temperature waste heat recovery device. The waste heat recovery device can filter particle dust in waste gas-containing oxygen and reduce the damage condition of waste heat recovery equipment.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium battery positive electrode material production, in particular to a lithium battery positive electrode material sintering roller kiln high-temperature oxygen separation system. Background Art

[0002] During the sintering production process of lithium battery positive electrode materials, a large amount of pure oxygen needs to be introduced into the roller kiln to stabilize the oxygen concentration in the roller kiln and stabilize the sintering process of the material. Since some carbon dioxide, nitrogen or other waste gases may be generated during the sintering process of the material, a large flow of pure oxygen needs to be introduced to ensure the purity of the oxygen in the roller kiln, and at the same time, the oxygen containing waste gas is discharged from the kiln. According to actual measurements, the concentration of oxygen discharged from the roller kiln is about 80%, which cannot be directly recycled into the kiln and can only be discharged into the atmosphere through the chimney. The normal production temperature in the roller kiln is 800℃, and the temperature of the discharged oxygen is nearly 700℃. At the same time, the discharged oxygen contains a large amount of dust generated during the sintering process. Conventional dust collectors cannot operate under 700℃ conditions and can only be discharged directly into the atmosphere, causing serious air pollution.

[0003] CN110836608A discloses a high-nickel ternary positive electrode material kiln sintering tail gas recovery and utilization system, the tail gas generated in the roller kiln is led out through the induced draft fan, pipe A is connected to the heat exchanger through pipe B, two valves are arranged on pipe B, a lead-out pipe C between the two valves is connected to a pure water tank, a lead-out pipe D of the heat exchanger is connected to an oxygen making device, a lead-out pipe E of the heat exchanger is connected to a pipe D between valves D and E, a lead-out pipe F on pipe E between valves F and G is connected to a gas storage tank, and the gas storage tank is connected to the roller kiln through pipe G; the heat exchanger also leads out a pipe H connected to pipe C; the pure water tank is connected to a condenser through a circulation pipe, the condenser is connected to the oxygen making device, and the bottom of the pure water tank is connected to an MVR evaporation device to realize waste heat recovery and utilization, but particulate dust cannot be prevented from entering the waste heat recovery equipment, and the waste heat recovery equipment is easily damaged. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a high-temperature oxygen separation system for a lithium battery positive electrode material sintering roller kiln which can filter particulate dust in exhaust gas oxygen and reduce damage to waste heat recovery equipment.

[0005] In order to solve the above technical problems, the utility model provides a high-temperature oxygen separation system for a lithium battery positive electrode material sintering roller kiln, comprising a roller kiln, wherein there are multiple roller kilns connected in parallel, a coarse dust collector is installed on each roller kiln, a high-temperature waste heat recovery device is installed on the coarse dust collector, a fine dust collector is installed on the high-temperature waste heat recovery device, a low-temperature waste heat recovery device is installed on the fine dust collector, a variable frequency centrifugal fan is installed on the low-temperature waste heat recovery device, and a storage tank I is installed at the outlet of the variable frequency centrifugal fan; each storage tank I is connected to an oxygen separation system after being connected in parallel, and a set of oxygen separation systems is used for dust removal and oxygen recovery of multiple roller kilns; both the high-temperature waste heat recovery device and the low-temperature waste heat recovery device are tubular cold water heat exchangers; and an acoustic nitrogen dust cleaner is arranged on the high-temperature waste heat recovery device.

[0006] By adopting the above technical scheme, a coarse dust collector, a high-temperature waste heat recovery device, a fine dust collector, a low-temperature waste heat recovery device, and a variable frequency centrifugal fan are installed in series between the roller kiln and storage tank I. Two sets of dust collectors are used to filter the oxygen twice to reduce the damage to the waste heat recovery device. Multiple roller kilns are combined into one set of oxygen separation system to reduce the floor space occupied by the oxygen separation system equipment.

[0007] Preferably, the oxygen separation system includes an oxygen separator and a compressor, the storage tank I is connected to the oxygen separator, the compressor is installed on the oxygen output port of the oxygen separator, and the storage tank II is installed at the outlet of the compressor.

[0008] By adopting the above technical solution, the oxygen separator is connected to the storage tank II through the compressor, and the separated oxygen is output to the storage tank II for recycling. The oxygen concentration in the gas purified by the oxygen separator is about 80%.

[0009] Preferably, the output port of storage tank II is connected to a plurality of roller kilns connected in parallel.

[0010] By adopting the above technical solution, oxygen is output to the roller kiln through storage tank II, thereby realizing oxygen recovery and utilization.

[0011] Preferably, the heat exchange water source is connected in parallel to the heat exchange inlets of the high-temperature waste heat recovery device and the low-temperature waste heat recovery device, and the heat exchange outlets of the high-temperature waste heat recovery device and the low-temperature waste heat recovery device are connected in parallel to the recovery pool.

[0012] By adopting the above technical solution, the temperature of the warm water after replacement by the high and low temperature waste heat recovery devices is 40-45°C. The warm water is combined and sent to the recovery pool to recover the waste heat. At the same time, the water temperature is naturally reduced to about 30°C and then returned to the high and low temperature waste heat recovery devices for recycling and energy saving.

[0013] Preferably, the coarse dust collector is a cyclone dust collector.

[0014] By adopting the above technical solution, the cyclone dust collector can pre-filter out most of the large dust particles, reducing the wear and blockage of the high-temperature waste heat recovery equipment.

[0015] Preferably, the fine dust collector is a cartridge dust collector, and the filter cartridge is a ceramic fiber filter cartridge.

[0016] By adopting the above technical solution, the ceramic fiber filter cartridge can withstand a temperature of 600°C. Once the cooling effect of the high-temperature waste heat recovery device deteriorates, the filter cartridge can withstand the impact of high-temperature flue gas in a short period of time, thus preventing the filter cartridge in the dust collector from burning due to high temperature.

[0017] Preferably, a pressure sensor is arranged in the roller kiln, and the pressure sensor is linked to the variable frequency centrifugal fan.

[0018] By adopting the above technical solution, the frequency conversion controller of the fan is linked with the pressure sensor in the roller kiln to control the pressure in the roller kiln in real time to ensure normal production.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. A coarse dust collector, a high-temperature waste heat recovery device, a fine dust collector, a low-temperature waste heat recovery device, and a variable frequency centrifugal fan are installed in series between the roller kiln and the storage tank I of the utility model. Two sets of dust collectors are used to filter oxygen twice to reduce the damage of the waste heat recovery device. Multiple roller kilns are combined to adopt one set of oxygen separation system to reduce the floor space occupied by the oxygen separation system equipment.

[0021] 2. The temperature of the warm water after replacement by the high and low temperature waste heat recovery device of the utility model is 40-45°C. The warm water is combined and sent to the recovery pool to recover the waste heat. At the same time, the water temperature is naturally reduced to about 30°C and then flows back to the high and low temperature waste heat recovery device for recycling and energy saving.

[0022] 3. The frequency conversion controller of the fan of the utility model is linked with the pressure sensor in the roller kiln to control the pressure in the roller kiln in real time to ensure normal production. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the utility model;

[0024] Figure 2 This is a schematic diagram of the oxygen filtration, cooling and recovery line of the utility model;

[0025] Figure 3 This is a schematic diagram of the oxygen separation system of the utility model;

[0026] Figure 4 It is a schematic diagram of the connection between the water exchange water source and the high-temperature waste heat recovery device and the low-temperature waste heat recovery device of the utility model.

[0027] Figure number: 1. Roller kiln, 2. Coarse dust collector, 3. High-temperature waste heat recovery device, 4. Fine dust collector, 5. Low-temperature waste heat recovery device, 6. Variable frequency centrifugal fan, 7. Storage tank I, 8. Oxygen separator, 9. Compressor, 10. Storage tank II, 11. Ceramic fiber filter cartridge, 12. Oxygen output port. DETAILED DESCRIPTION

[0028] like Figure 1 , 2 As shown, the high-temperature oxygen separation system of the roller kiln 1 for sintering positive electrode materials of lithium batteries includes multiple roller kilns 1 connected in parallel, each roller kiln 1 is equipped with a rough dust collector 2, and a high-temperature waste heat recovery device 3 is installed on the rough dust collector 2. The high-temperature waste heat recovery device 3 is a tubular cold water heat exchanger, the system is simple and reliable, the warm water after replacement can be recycled, saving energy, and an acoustic nitrogen dust cleaner is arranged on the high-temperature waste heat recovery device 3, which is not shown in the figure, to prevent dust accumulation on the heat exchange tubes in the heat exchanger. A fine dust collector 4 is installed on the high-temperature waste heat recovery device 3, and a low-temperature waste heat recovery device 5 is installed on the fine dust collector 4. A variable frequency centrifugal fan 6 is provided at the end of the oxygen filtering and cooling recovery line of each roller kiln 1 to draw oxygen from the roller kiln 1 and transport it to the oxygen separation system. The outlet of the low-temperature waste heat recovery device 5 is connected to the variable frequency centrifugal fan 6, and a storage tank Ⅰ7 is installed at the outlet of the variable frequency centrifugal fan 6. Each storage tank Ⅰ7 is connected in parallel to the oxygen separation system, and multiple roller kilns 1 use one oxygen separation system for dust removal and oxygen recovery. The low-temperature waste heat recovery device 5 is a tubular cold water heat exchanger. The system is simple and reliable, and the cooling water uses 30°C normal temperature water. In this application, a coarse dust collector 2, a high-temperature waste heat recovery device 3, a fine dust collector 4, a low-temperature waste heat recovery device 5, and a variable frequency centrifugal fan 6 are installed in series between the roller kiln 1 and the storage tank Ⅰ7. Two sets of dust collectors are used to filter the oxygen twice to reduce the damage of the waste heat recovery device. Multiple roller kilns are combined to use one oxygen separation system to reduce the floor space occupied by the oxygen separation system equipment.

[0029] The coarse dust collector 2 is a cyclone dust collector, which can filter out most of the large dust particles in advance, reducing the wear and clogging of the high-temperature waste heat recovery equipment. The fine dust collector 4 is a cartridge dust collector, and the filter cartridge is a ceramic fiber filter cartridge 11. The ceramic fiber filter cartridge 11 has a temperature resistance of 600°C. Once the cooling effect of the high-temperature waste heat recovery device deteriorates, the filter cartridge can withstand the impact of high-temperature flue gas in a short period of time, avoiding the filter cartridge in the dust collector from burning due to high temperature.

[0030] The variable frequency centrifugal fan 6 of each roller kiln 1 is controlled by a separate variable frequency. Due to production requirements, the pressure in each roller kiln 1 must be controlled at -10Pa to -2Pa. The fan variable frequency controller is linked with the pressure sensor in the roller kiln 1, and PID regulation is configured to control the pressure in the roller kiln 1 in real time to ensure normal production. The pressure sensor and PLC are connected through a signal line, and the variable frequency controller of the variable frequency centrifugal fan 6 and the PLC are connected using 485 communication.

[0031] like Figure 3 As shown, the oxygen separation system includes an oxygen separator 8 and a compressor 9, a storage tank Ⅰ7 is connected to the oxygen separator 8, a compressor 9 is installed on the oxygen output port 12 of the oxygen separator 8, and a storage tank Ⅱ10 is installed at the outlet of the compressor 9. The oxygen separator 8 is connected to the storage tank Ⅱ10 through the compressor 9, and the separated oxygen is output to the storage tank Ⅱ10 for recycling. The oxygen concentration in the gas purified by the oxygen separator 8 is about 80%. The remaining 20% ​​of the waste gas is discharged through the waste gas outlet 13 of the oxygen separator 8, and the waste gas is carbon dioxide and nitrogen.

[0032] The output port of the storage tank II 10 is connected to a plurality of roller kilns 1 connected in parallel, and oxygen is output to the air inlet of the roller kiln through the storage tank II 10, so that oxygen recovery and utilization is realized.

[0033] like Figure 4 As shown, the heat exchange water source is connected in parallel to the heat exchange inlet of the high-temperature waste heat recovery device 3 and the low-temperature waste heat recovery device 5, and the heat exchange outlet of the high-temperature waste heat recovery device 3 and the low-temperature waste heat recovery device 5 is connected in parallel to the recovery pool. The temperature of the warm water after the high and low-temperature waste heat recovery devices is 40-45°C. The warm water is combined and sent to the recovery pool to recover the residual heat. At the same time, the water temperature is naturally reduced to about 30°C and then returned to the high and low-temperature waste heat recovery devices for recycling and energy saving.

[0034] There are often 3-4 roller kilns 1 in a workshop. The space inside and outside the workshop is narrow, so a set of integrated recovery systems is set up for multiple roller kilns 1. Each roller kiln 1 is equipped with a coarse dust collector 2, a high-temperature waste heat recovery device 3, a fine dust collector 4, a low-temperature waste heat recovery device 5, an induced draft fan and an oxygen storage tank. The high-temperature oxygen (700℃) in a roller kiln 1 first passes through the coarse dust collector 2, which can reduce the dust concentration to 5-10g / Nm³. The coarse dust collector 2 uses a cyclone dust collector. The temperature of the high-temperature waste heat recovery device 3 is reduced to 300℃. The high-temperature waste heat recovery device 3 uses cold water replacement, the cold water temperature is 30℃, and the warm water after replacement reaches 45-50℃. Then the 250℃ oxygen enters the fine dust collector 4 to filter the dust concentration to below 5mg / Nm³. The fine dust collector 4 uses a ceramic fiber cartridge dust collector. A low-temperature waste heat recovery device 5 is set after the fine dust collector 4. After the oxygen enters the low-temperature waste heat recovery device 5, the temperature is reduced to about 35°C. The low-temperature waste heat recovery device 5 uses cold water replacement, and the cold water temperature is 30°C. The warm water after replacement reaches 35°C. A variable frequency centrifugal fan 6 is set after the low-temperature waste heat recovery device 5. A 10m³ oxygen storage tank is set after the variable frequency centrifugal fan 6. The system is equipped with an oxygen main pipe, and the outlet of each oxygen storage tank is connected to the oxygen main pipe. The oxygen main pipe sends oxygen to the oxygen separation system. The oxygen concentration after separation by the oxygen separation system reaches more than 99%. The oxygen is finally compressed to 0.5MPa by the compressor 9 and re-enters the kiln for recycling.

[0035] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments. Without departing from the principles, the embodiments of the present invention may be deformed or modified in any way.

Claims

1. A high-temperature oxygen separation system for a lithium battery positive electrode material sintering roller kiln, comprising a roller kiln (1), characterized in that: The roller kilns (1) are multiple and connected in parallel. A rough dust collector (2) is installed on each roller kiln (1). A high-temperature waste heat recovery device (3) is installed on the rough dust collector (2). A fine dust collector (4) is installed on the high-temperature waste heat recovery device (3). A low-temperature waste heat recovery device (5) is installed on the fine dust collector (4). A variable frequency centrifugal fan (6) is installed on the low-temperature waste heat recovery device (5). A storage tank I (7) is installed at the outlet of the variable frequency centrifugal fan (6). After being connected in parallel, each storage tank I (7) is connected to an oxygen separation system. A set of oxygen separation systems is used for dust removal and oxygen recovery of multiple roller kilns (1). Both the high-temperature waste heat recovery device (3) and the low-temperature waste heat recovery device (5) are tubular cold water heat exchangers. A sonic nitrogen dust cleaner is provided on the high-temperature waste heat recovery device (3).

2. The high temperature oxygen separation system for lithium battery positive electrode material sintering roller kiln according to claim 1, characterized in that: The oxygen separation system comprises an oxygen separator (8) and a compressor (9), a storage tank I (7) is connected to the oxygen separator (8), the compressor (9) is installed on the oxygen output port (12) of the oxygen separator (8), and a storage tank II (10) is installed at the outlet of the compressor (9).

3. The high temperature oxygen separation system for lithium battery positive electrode material sintering roller kiln according to claim 1, characterized in that: The outlet of the storage tank II (10) is connected to a plurality of roller kilns (1) connected in parallel.

4. The high temperature oxygen separation system for sintering roller kiln of lithium battery positive electrode material according to claim 1, characterized in that: The heat exchange water source is connected in parallel to the heat exchange inlets of the high-temperature waste heat recovery device (3) and the low-temperature waste heat recovery device (5), and the heat exchange outlets of the high-temperature waste heat recovery device (3) and the low-temperature waste heat recovery device (5) are connected in parallel to the recovery pool.

5. The high temperature oxygen separation system for lithium battery positive electrode material sintering roller kiln according to claim 1, characterized in that: The coarse dust collector (2) is a cyclone dust collector.

6. The high temperature oxygen separation system for lithium battery positive electrode material sintering roller kiln according to claim 1, characterized in that: The fine dust collector (4) is a cartridge dust collector, and the cartridge is a ceramic fiber cartridge (11).

7. The high temperature oxygen separation system for lithium battery positive electrode material sintering roller kiln according to claim 1, characterized in that: A pressure sensor is arranged in the roller kiln (1), and the pressure sensor is linked to the variable frequency centrifugal fan (6).

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