Pelletizing temporary storage bin nitrogen replacement system and control method thereof

Abstract

The invention provides a nitrogen replacement system for a granulation temporary storage bin. The nitrogen replacement system comprises the granulation temporary storage bin, a feeding pipeline and a nitrogen replacement pipeline, the feeding pipeline is used for conveying coating granulation raw materials into the granulation temporary storage bin, a block valve is installed in the feeding pipeline, and connection and disconnection between the feeding pipeline and the granulation temporary storage bin are controlled through the block valve; the nitrogen replacement pipeline comprises a gas supply pipeline for conveying nitrogen into the granulation temporary storage bin and a gas exhaust pipeline for exhausting gas in the granulation temporary storage bin, a gas inlet valve is mounted in the gas supply pipeline to control the connection and disconnection of the gas supply pipeline, and a gas exhaust valve is mounted in the gas exhaust pipeline to control the connection and disconnection of the gas exhaust pipeline. On one hand, material oxidation can be avoided, and the coating capacity of the coating raw materials is guaranteed; and on the other hand, the explosion risk can be reduced, the safety of the equipment is improved, and air can be effectively prevented from entering the granulation temporary storage bin through the feeding pipeline in the nitrogen replacement process.

Description

Technical Field

[0001] The invention relates to the technical field of battery manufacturing, and in particular to a nitrogen replacement system for a granulation temporary storage bin and a control method thereof. Background Art

[0002] Coating granulation is a key link in the production process of artificial graphite negative electrode materials. The effect of coating granulation directly affects the performance of artificial graphite products. The main factors affecting the effect of artificial graphite coating granulation are aggregate index, coating agent index, coating granulation heating curve and nitrogen atmosphere protection of granulation kettle. During the coating granulation process, the oxygen content in the granulation kettle must be controlled below 0.5%. If the oxygen content in the granulation kettle is too high, on the one hand, the material will be oxidized with oxygen during the heating process, resulting in a decrease in the coating ability of the coating agent and a high material specific surface area, which affects the material performance; on the other hand, if the oxygen content in the granulation kettle is too high, there is a risk of explosion when the concentration of volatile substances in the material exceeds the explosion limit. Summary of the invention

[0003] In order to solve the technical problems existing in the background technology, the present invention proposes a nitrogen replacement system for a granulation temporary storage bin and a control method thereof.

[0004] The present invention provides a nitrogen replacement system for a granulation temporary storage bin, comprising: a granulation temporary storage bin, a feeding pipeline, and a nitrogen replacement pipeline;

[0005] The feeding pipeline is used to transport the coated granulation raw materials to the granulation temporary storage bin. A shutoff valve is installed in the feeding pipeline to control the connection and disconnection between the feeding pipeline and the granulation temporary storage bin through the shutoff valve;

[0006] The nitrogen replacement pipeline includes an air supply pipeline for conveying nitrogen into the granulation temporary storage bin and an exhaust pipeline for discharging gas in the granulation temporary storage bin, and an air inlet valve is installed in the air supply pipeline to control the on-off of the air supply pipeline, and an exhaust valve is installed in the exhaust pipeline to control the on-off of the exhaust pipeline.

[0007] Preferably, the air inlet valve, the exhaust valve, and the shut-off valve are interlocked with the feed amount of the granulation temporary storage bin. When the feed amount of the granulation temporary storage bin reaches a preset value, the feeding pipeline stops feeding, and after a time period T, the shut-off valve is closed, and the air inlet valve and the exhaust valve are opened in sequence.

[0008] Preferably, when the nitrogen replacement pipeline is started and enters the working state, the intake valve and the exhaust valve are closed after each time period T1, and opened again after an interval of time period T2, and this cycle is repeated until the number of cycles reaches a preset value.

[0009] Preferably, the feed amount of the granulation temporary storage bin is set in weight units.

[0010] Preferably, the feeding pipeline includes a raw material conveying pipeline connected to the granulation temporary storage bin and a vacuum pipeline connected to the granulation temporary storage bin, and the shut-off valve includes a shut-off valve A installed in the raw material conveying pipeline and a shut-off valve B installed in the vacuum pipeline.

[0011] Preferably, the air inlet end of the exhaust pipeline is connected to the vacuum pipeline, and the connection point between the air inlet end and the vacuum pipeline is located between the shut-off valve B and the granulation temporary storage bin.

[0012] Preferably, a filter bag is provided at the connection end between the vacuum extraction pipeline and the granulation temporary storage bin, and the filter bag is installed in the granulation temporary storage bin.

[0013] Preferably, a vacuum interface is provided on the top of the granulation temporary storage bin, the filter bag is vertically suspended in the granulation temporary storage bin, the port on the top is fixed to the vacuum interface, and the air inlet end of the vacuum pipeline is connected to the vacuum interface.

[0014] Preferably, the vacuum pipeline includes an air supply pipe connected to the granulation temporary storage bin, and a vacuum equipment connected to the air supply pipe.

[0015] Preferably, the gas outlet end of the exhaust pipeline is connected to a tail gas treatment tower.

[0016] In the present invention, the feeding pipeline is used to transport the coated granulation raw materials into the granulation temporary storage bin, and the shutoff valve in the feeding pipeline is used to control the on-off between the feeding pipeline and the granulation temporary storage bin; the nitrogen replacement pipeline includes an air supply pipeline and an exhaust pipeline, the air supply pipeline is used to transport nitrogen into the granulation temporary storage bin, and the air intake valve in the air supply pipeline is used to control the on-off of the air supply pipeline; the exhaust pipeline is used to extract the gas in the granulation temporary storage bin, and the exhaust valve in the exhaust pipeline is used to control the on-off of the exhaust pipeline. During feeding, the air intake valve and the exhaust valve are in a closed state, and the shutoff valve is opened; during nitrogen replacement, the feeding pipeline stops conveying, the shutoff valve is closed, and the air supply pipeline and the exhaust pipeline work to replace the gas in the temporary storage bin, reduce the oxygen content in the temporary storage bin, on the one hand to avoid material oxidation and ensure the coating capacity of the coated raw materials; on the other hand to reduce the risk of explosion and improve the safety of the equipment. In addition, the design of the shut-off valve can effectively prevent air from entering the granulation temporary storage bin through the feeding pipeline during the nitrogen replacement process, thereby ensuring the nitrogen replacement effect inside the granulation temporary storage bin and further ensuring the material coating granulation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural schematic diagram of a nitrogen replacement system for a granulation temporary storage bin proposed by the present invention. DETAILED DESCRIPTION

[0018] Reference Figure 1 The present invention provides a nitrogen replacement system for a granulation temporary storage bin, comprising: a granulation temporary storage bin 1, a feeding pipeline, and a nitrogen replacement pipeline;

[0019] The feeding pipeline is connected to the granulation temporary storage bin 1 to transport the coated granulation raw material into the granulation temporary storage bin 1. A shut-off valve 2 is installed in the feeding pipeline to control the on-off between the feeding pipeline and the granulation temporary storage bin 1 through the shut-off valve 2. The nitrogen replacement pipeline includes an air supply pipeline 3 and an exhaust pipeline 4. The air supply pipeline 3 is connected to the granulation temporary storage bin 1 to transport nitrogen into the granulation temporary storage bin 1. An air intake valve 5 is installed in the air supply pipeline 3 to control the on-off of the air supply pipeline 3. The exhaust pipeline 4 is connected to the granulation temporary storage bin 1 for the discharge of the gas in the granulation temporary storage bin 1. An exhaust valve 6 is installed in the exhaust pipeline 4 to control the on-off of the exhaust pipeline 4.

[0020] During feeding, the air inlet valve 5 and the exhaust valve 6 are in a closed state, the shut-off valve 2 is opened, and the feeding pipeline transports the coated granulation raw materials to the temporary storage bin; during nitrogen replacement, the feeding pipeline stops transporting, and the shut-off valve 2 is closed. At this time, the air inlet valve 5 and the exhaust valve 6 are opened, and the air supply pipeline 3 and the exhaust pipeline 4 work at the same time to replace the gas in the temporary storage bin, so as to reduce the oxygen content in the temporary storage bin. On the one hand, it can avoid oxidation of the material and ensure the coating ability of the coated raw materials; on the other hand, it can reduce the risk of explosion and improve the safety of the equipment. In addition, the design of the shut-off valve 2 can effectively prevent the air from entering the granulation temporary storage bin 1 through the feeding pipeline during the nitrogen replacement process, ensure the replacement effect of the nitrogen inside the granulation temporary storage bin 1, and then ensure the material coating granulation effect.

[0021] Furthermore, the air inlet valve 5, the exhaust valve 6 and the shutoff valve 2 in this embodiment are interlocked with the feed amount of the granulation temporary storage bin 1. When the feed amount of the granulation temporary storage bin 1 reaches a preset value, the feeding pipeline stops feeding, and after a time period T, the shutoff valve 2 is closed, and the air inlet valve 5 and the exhaust valve 6 are opened in sequence. The whole process does not require manual nitrogen replacement, which improves the nitrogen replacement efficiency and reduces the risk of nitrogen replacement leakage in the granulation temporary storage bin 1.

[0022] The feed amount of the granulation temporary storage bin 1 in this embodiment is set in weight units.

[0023] Furthermore, a ventilation time T1 and a ventilation interval time T2 are preset; when the nitrogen replacement pipeline is started and enters the working state, each time a preset ventilation time T1 passes, the intake valve 5 and the exhaust valve 6 are closed, and after a ventilation interval time T2, they are opened again to complete a ventilation cycle..., and the cycle is repeated in sequence until the number of cycles reaches the preset value. The specific working method is as follows:

[0024] 1. The feed volume of the granulation temporary storage bin 1 is preset to be 1200 kg, the time period T is 30 seconds, the ventilation time T1 is 180 seconds, the ventilation interval time T2 is 15 seconds, and the number of cycles is 3 times;

[0025] 2. When the feed volume of the granulation temporary storage bin 1 reaches 1200Kg, the feed pipeline stops feeding, and after an interval of 30S, the nitrogen replacement pipeline starts, and the intake valve 5 and the exhaust valve 6 are opened successively, and the nitrogen replacement lasts for 180S;

[0026] 3. After the first nitrogen replacement is completed, the next nitrogen replacement shall be carried out after an interval of 15 seconds, and nitrogen replacement shall be carried out three times in succession. The nitrogen replacement time of the temporary storage warehouse shall not exceed 600 seconds.

[0027] Take gas samples from the nitrogen replacement exhaust end of the granulation temporary storage warehouse 1 to test the oxygen content of the replacement gas in the warehouse, which is lower than 0.1%; after the material of the present application is coated and granulated, the material D 50 Average particle size 18.20um, tap density 0.61g / cm 3 , the ratio is 0.68m 2 / g.

[0028] The feeding pipeline in this embodiment includes a raw material conveying pipeline 7 connected to the granulation temporary storage bin 1, and a vacuuming pipeline 8 connected to the granulation temporary storage bin 1, and the cut-off valve 2 includes a cut-off valve A21 installed in the raw material conveying pipeline 7 and a cut-off valve B22 installed in the vacuuming pipeline 8. During feeding, the vacuuming pipeline 8 vacuumizes the granulation temporary storage bin 1, so that the interior is in a negative pressure state, and then the coated granulation raw material conveyed by the raw material conveying pipeline 7 is sucked into the bin. During nitrogen replacement, the cut-off valve A21 and the cut-off valve B22 are both in a closed state.

[0029] The vacuum pipeline 8 in this embodiment includes an air supply pipe connected to the granulation temporary storage bin 1 and a vacuum equipment connected to the air supply pipe, wherein the vacuum equipment includes a Roots blower.

[0030] In this embodiment, a filter bag 9 is provided at the connection end between the vacuum extraction pipeline 8 and the granulation temporary storage bin 1. The filter bag 9 is installed in the granulation temporary storage bin 1 to prevent the raw materials in the bin from being taken out during vacuum extraction.

[0031] The specific design of the filter bag 9 is as follows: a vacuum interface is provided on the top of the granulation temporary storage bin 1, the filter bag 9 is vertically suspended in the granulation temporary storage bin 1, the port on the top is fixed at the vacuum interface, and the air inlet end of the vacuum pipeline 8 is connected to the vacuum interface. This design can effectively increase the air inlet surface of the filter bag 9.

[0032] Furthermore, the air inlet end of the exhaust pipeline 4 in this embodiment is connected to the vacuum pipeline 8, and the connection point between the air inlet end and the vacuum pipeline 8 is located between the shut-off valve B22 and the granulation temporary storage bin 1, so that the exhaust pipeline 4 and the vacuum pipeline 8 form a local colinear structure, which can not only simplify the structure, but also save line costs.

[0033] The outlet end of the exhaust pipe 4 in this embodiment is connected to the exhaust gas treatment tower in the exhaust gas treatment system, so as to utilize the negative pressure inside the exhaust gas treatment tower to form negative pressure at the exhaust end of the exhaust pipe 4, thereby improving the nitrogen replacement efficiency without adding negative pressure equipment.

[0034] It can be seen from the above that the present invention has at least the following advantages compared with the prior art:

[0035] 1. Install a shutoff valve 2 in the feeding pipeline of the granulation temporary storage bin 1. Close the shutoff valve 2 in the feeding pipeline during nitrogen replacement to prevent air from leaking into the feeding pipeline during nitrogen replacement, which may affect the replacement effect;

[0036] 2. The feed amount of the granulation temporary storage bin 1 is interlocked with the nitrogen replacement valve inlet valve 5 and exhaust valve 6, so there is no need to manually replace the nitrogen, which improves the nitrogen replacement efficiency and reduces the risk of leakage of nitrogen replacement in the granulation temporary storage bin 1;

[0037] 3. The nitrogen replacement pipeline enters the tail gas treatment tower, that is, the outlet end of the exhaust pipe is cut off from the tail gas treatment tower, and the negative pressure of the tail gas treatment system is used to vacuum the granulation temporary storage bin 1, so as to accelerate the nitrogen replacement effect without installing additional nitrogen replacement vacuum equipment.

[0038] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A nitrogen replacement system for a granulation temporary storage bin, characterized in that: include: Granulation temporary storage bin, feeding pipeline, and nitrogen replacement pipeline; The feeding pipeline is used to transport the coated granulation raw materials into the granulation temporary storage bin, and a shut-off valve is installed in the feeding pipeline to control the on-off between the feeding pipeline and the granulation temporary storage bin through the shut-off valve; the nitrogen replacement pipeline includes an air supply pipeline for transporting nitrogen into the granulation temporary storage bin and an exhaust pipeline for discharging the gas in the granulation temporary storage bin, and an air inlet valve is installed in the air supply pipeline to control the on-off of the air supply pipeline, and an exhaust valve is installed in the exhaust pipeline to control the on-off of the exhaust pipeline.

2. The nitrogen replacement system for granulation temporary storage bin according to claim 1 is characterized in that: The air inlet valve, the exhaust valve, and the shut-off valve are interlocked with the feed amount of the granulation temporary storage bin. When the feed amount of the granulation temporary storage bin reaches the preset value, the feeding pipeline stops feeding, and after a time period T, the shut-off valve is closed, and the air inlet valve and the exhaust valve are opened in sequence.

3. The granulation temporary storage silo nitrogen replacement system according to claim 2 is characterized in that: When the nitrogen replacement pipeline is started and enters the working state, the intake valve and the exhaust valve are closed after each time period T1, and are opened again after an interval of time period T2, and this cycle is repeated until the number of cycles reaches a preset value.

4. The granulation temporary storage silo nitrogen replacement system according to claim 2 is characterized in that: The feed amount of the granulation temporary storage bin is set in weight units.

5. The granulation temporary storage silo nitrogen replacement system according to claim 1 is characterized in that: The feeding pipeline includes a raw material conveying pipeline connected to the granulation temporary storage bin and a vacuum pipeline connected to the granulation temporary storage bin. The shut-off valve includes a shut-off valve A installed in the raw material conveying pipeline and a shut-off valve B installed in the vacuum pipeline.

6. The nitrogen replacement system for granulation temporary storage bin according to claim 5 is characterized in that: The air inlet end of the exhaust pipeline is connected to the vacuum pipeline, and the connection point between the air inlet end and the vacuum pipeline is located between the cut-off valve B and the granulation temporary storage bin.

7. The nitrogen replacement system for granulation temporary storage bin according to claim 5 is characterized in that: A filter bag is arranged at the connection end of the vacuum pipeline and the granulation temporary storage bin, and the filter bag is installed in the granulation temporary storage bin.

8. The nitrogen replacement system for the granulation temporary storage bin according to claim 7 is characterized in that: A vacuum interface is provided on the top of the granulation temporary storage bin, the filter bag is vertically suspended in the granulation temporary storage bin, the port on the top is fixed at the vacuum interface, and the air inlet end of the vacuum pipeline is connected to the vacuum interface.

9. The nitrogen replacement system for granulation temporary storage bin according to claim 5, characterized in that: The vacuum pipeline includes an air supply pipe connected to the granulation temporary storage bin and a vacuum pumping device connected to the air supply pipe.

10. The nitrogen replacement system for temporary granulation storage bin according to any one of claims 1 to 9, characterized in that: The gas outlet end of the exhaust pipeline is connected to the exhaust gas treatment tower.

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