A packaging system and method for bulk material having a high gas content and a low bulk density

Abstract

This invention belongs to the field of material packaging technology, specifically relating to a packaging system and method for materials with high gas content and low bulk density. The system includes a degassing device, a temporary storage bin, a feeding device, and packaging equipment. The degassing device is connected to the outlet of the upstream feeding equipment and is used to degas the incoming material by compression. The temporary storage bin is used to temporarily store the material processed by the degassing device. The feeding device is used to transfer the material in the temporary storage bin to the packaging equipment. This invention can completely remove the gas trapped in the gaps between fine powder particles before the material enters the packaging bag, greatly avoiding the risks of bulging and overturning during storage and transportation. By setting the feed chute as an upstream buffer and the temporary storage bin as a downstream buffer, the "degassing cycle" and "front-end and back-end operating conditions" are completely separated, solving the pain point that traditional continuous degassing screws must start and stop synchronously with the packaging machine, frequently interrupting the upstream process, and greatly improving the overall utilization rate of the equipment.

Description

Technical Field

[0001] This invention relates to the field of material packaging technology, and in particular to a packaging system and method for materials with high gas content and low bulk density. Background Technology

[0002] In the production lines for new energy battery materials, especially cathode materials such as lithium iron phosphate, after sand milling, drying, and iron removal processes, the materials are typically conveyed pneumatically or by gravity to the downstream packaging process. Because these materials generally undergo surface modification treatment, they exhibit physical characteristics such as high gas content, extremely low bulk density (typically ≤0.4 g / cm³), and extremely high powder flowability; making it difficult for conventional packaging processes to simultaneously meet the requirements of high-density filling, dust-free sealing, and continuous, high-efficiency production.

[0003] Currently, the most common powder packaging process for the aforementioned materials involves directly filling the material into ton bags or valve bags and then vacuuming the entire bag. Because a large amount of process gas is trapped between the material particles, relying solely on the negative pressure of the bag is insufficient to completely replace the gas in the gaps between the micron-sized particles, resulting in excessively large finished bags and high storage and transportation costs. More seriously, materials such as lithium iron phosphate, after surface modification, have near-liquid flow properties, making them highly susceptible to being ejected with airflow during vacuuming, causing a "powder extraction" phenomenon. This not only clogs the vacuum filter but also leads to seal failure during bag heat sealing due to powder adhesion, significantly increasing the risk of bulging and overturning during later storage and transportation. To improve degassing, some packaging production lines have introduced degassing spirals with filters, attempting to expel gas simultaneously during the material feeding process. However, this continuous structure has inherent shortcomings when handling materials with high gas content: to ensure output, the feed end is usually open at all times, making it impossible to form an effective airtight seal. Large amounts of ambient air seep in, making it difficult to maintain the system vacuum and significantly reducing degassing efficiency. Simultaneously, upstream equipment such as iron separators and screening machines often operate continuously 24 hours a day, while downstream ton-bag packaging requires periodic shutdowns for bag replacement. Existing degassing spirals lack material retention and buffering capabilities. Bag replacement either forces a complete shutdown of the upstream line, disrupting upstream process stability, or causes material splashing and waste. Some packaging line solutions use vertical vacuum degassing tanks, which extract gas from the tank by closing the feed valve. However, for highly free-flowing fine powders, simply relying on gravity to loosely accumulate in the tank easily creates an "air cushion effect" or bridging, leading to blockage (channeling) of the gas discharge channel and uneven degassing. Furthermore, after degassing, due to the lack of a forced pushing mechanism, the now-dense material is prone to getting stuck at the discharge port, hindering smooth transition to subsequent precision weighing and feeding processes.

[0004] In summary, existing technologies generally suffer from incomplete degassing, production line cycle conflicts, and material discharge blockages when handling powders with high gas content, low bulk density, and high flowability. Therefore, there is an urgent need for a packaging process suitable for materials with high gas content, good flowability, and low bulk density. This process should be able to pre-degas the material before packaging, decouple upstream and downstream production cycles, enable rapid filling, and prevent bridging, powder spraying, bulging, or gas expansion. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned shortcomings of the prior art and provide a packaging process suitable for materials with high gas content and low bulk density. This process can achieve pre-degassing of the packaging material, improve the bulk density of the material, and enable the material to be filled quickly without bulging or gas expansion.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a packaging system for materials with high gas content and low bulk density, including a degassing device, a temporary storage bin, a feeding device, and packaging equipment; The feed end of the degassing device is connected to the outlet of the upstream feeding equipment, and is used to squeeze and degas the material being conveyed. The inlet of the temporary storage bin is connected to the outlet of the degassing device and is used to temporarily store materials processed by the degassing device. The feed inlet of the feeding device is connected to the outlet of the temporary storage bin, and is used to transfer the materials in the temporary storage bin to the packaging equipment. The packaging equipment is connected to the discharge port of the feeding device and is used to package materials.

[0007] Furthermore, there are multiple degassing devices, with one degassing device corresponding to one or more upstream feeding devices, or one upstream feeding device corresponding to multiple degassing devices. Of course, one degassing device can correspond to one or more packaging devices, or one packaging device can correspond to multiple degassing devices.

[0008] Furthermore, the upstream feeding equipment includes an iron separator, and the degassing device is located below the iron separator.

[0009] Furthermore, the degassing device includes a housing with a degassing chamber inside. A negative pressure port is provided on the housing to create a negative pressure in the degassing chamber. The degassing chamber is also equipped with a stirring and squeezing mechanism to stir and squeeze the material in the degassing chamber, and also has a discharge function to prevent the formation of an "air cushion effect" or bridging phenomenon.

[0010] Furthermore, the mixing and extrusion mechanism includes a spiral sleeve, inside which spiral blades are provided.

[0011] Furthermore, the degassing device also includes a feed chute, which serves to buffer materials; a feed valve is provided at the lower end of the feed chute; and a discharge valve is provided at the outlet end of the mixing and extrusion mechanism.

[0012] Furthermore, it also includes a control unit configured to perform the following operations: During the degassing stage, both the feed valve and the discharge valve are kept closed. The negative pressure interface is activated to extract air and drive the stirring and extrusion mechanism to stir the material in the degassing chamber to prevent bridging. During the discharge stage, the feed valve is kept closed, the discharge valve is opened, and the spiral blades in the stirring and extrusion mechanism are driven to rotate, so that the degassed material is discharged into the temporary storage bin. During the feeding stage, the discharge valve is closed and the feed valve is opened, allowing the material in the feed chute to fall into the degassing chamber.

[0013] The present invention also provides a packaging method for materials with high gas content and low bulk density, utilizing the above-mentioned system, specifically including the following steps: S1, Material Loading Stage: The upstream feeding equipment operates continuously, continuously feeding material into the feed chute. The discharge valve of the degassing device is closed, and the feed valve of the degassing device is opened, allowing the material in the feed chute to enter the degassing chamber of the degassing device. S2, Degassing stage: Close the feed valve of the degassing device and activate the negative pressure interface to generate negative pressure in the degassing chamber. At the same time, start the stirring and extrusion mechanism in the degassing device to stir and agitate the material, making it easier for the gas in the material to be discharged. S3, Discharge Stage: After degassing is completed, open the discharge valve of the degassing device to allow the mixing and extrusion mechanism to continue working and discharge the degassed dense material into the temporary storage bin. S4, Replenishment Stage: Close the discharge valve of the degassing device, open the feed valve of the degassing device, and let the material buffered in the feed chute continue to fall into the degassing chamber of the degassing device. Return to step S2 and enter the next round of degassing treatment cycle. S5. Packaging: Once a certain amount of material is stored in the temporary storage bin, the feeding device is activated to supply the material in the temporary storage bin to the packaging equipment for bagging.

[0014] Furthermore, there are multiple degassing devices, and the correspondence between the degassing devices and the upstream feeding equipment is many-to-1 or 1-to-many, with each degassing device being independently controlled. This facilitates the alternating operation of each degassing device, decoupling it from the production cycle of the upstream feeding equipment. That is, the upstream feeding equipment can operate continuously, while the multiple degassing devices operate in turn. Even if one of the degassing devices malfunctions, the other degassing devices can still operate normally under the control of the control unit, ensuring the continuity and stability of the entire degassing production line.

[0015] The beneficial effects of this invention are: 1. The degassing device in this invention is equipped with a negative pressure interface and a stirring and squeezing mechanism, which can completely remove the gas trapped in the gaps between fine powder particles before the material enters the packaging bag. Compared with the traditional "overall vacuuming inside the bag" process, it avoids the problem of high-speed airflow carrying powder to wash away the vacuum filter and heat seal, fundamentally eliminating the sealing failure caused by powder sticking to the bag opening, as well as the risk of bulging and overturning during the storage and transportation of finished products. 2. After degassing before packaging, the density of the material increases, allowing for more material to be packed into the same volume of ton bags. Furthermore, for highly fluid materials, pre-degassing before packaging facilitates precision control, prevents bag tipping during transport, and avoids powder extraction during the subsequent vacuum heat sealing process.

[0016] 3. By setting the feed chute as an upstream buffer and the temporary storage bin as a downstream buffer, the complete separation of the "degassing cycle" and "front-end and back-end operating conditions" is achieved: during degassing, both valves are closed, the upstream equipment can continue to supply materials, and the materials are temporarily stored in the chute without interrupting the front-end production; when the downstream packaging equipment stops to change bags, the degassing device can still operate normally and store the materials in the temporary storage bin; this design solves the pain point that the traditional continuous degassing screw must start and stop synchronously with the packaging machine and frequently interrupt the upstream process, and the overall equipment utilization rate (OEE) is greatly improved.

[0017] 4. In this invention, there are multiple degassing devices, and the correspondence between the degassing devices and the upstream feeding equipment is many to one or one to many. Each degassing device can work in turn, which improves packaging efficiency and makes the stability of the whole system higher. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the system in Embodiment 1 of the present invention; Figure 2 yes Figure 1 Enlarged view of section A; In the diagram: 1. Iron separator; 2. Degassing device; 21. Feed chute; 22. Feed valve; 23. Discharge valve; 24. Negative pressure interface; 25. Spiral sleeve; 26. Shell; 3. Temporary storage bin; 4. Feeding device; 5. Packaging equipment. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Example

[0020] like Figure 1-2 As shown, this embodiment is a packaging system for materials with high gas content and low bulk density, particularly suitable for lithium iron phosphate processes. It mainly includes a degassing device 2, a temporary storage bin 3, a feeding device 4, and a packaging device 5. The inlet of the degassing device 2 is connected to the outlet of the upstream feeding device for degassing the incoming material. The inlet of the temporary storage bin 3 is connected to the outlet of the degassing device 2 for temporarily storing the material processed by the degassing device 2. The inlet of the feeding device 4 is connected to the outlet of the temporary storage bin 3 for transferring the material from the temporary storage bin 3 to the packaging device 5. The packaging device 5 is connected to the outlet of the feeding device 4 for packaging the material.

[0021] In this embodiment, there are two degassing devices 2, each of which corresponds to multiple upstream feeding devices. The upstream feeding devices include an iron separator 1, and the degassing device 2 is located below the iron separator 1.

[0022] In this embodiment, the degassing device 2 includes a housing 26, inside which a degassing chamber is formed. A negative pressure interface 24 is provided on the housing to create a negative pressure in the degassing chamber. A stirring and pressing mechanism is also provided at the bottom of the degassing chamber. This mechanism stirs and presses the material in the degassing chamber and also has a discharge function to prevent the formation of an "air cushion effect" or bridging. The degassing device 2 also includes a feed chute 21, which buffers the material. A feed valve 22 is provided at the lower end of the feed chute 21. The stirring and pressing mechanism includes a spiral sleeve 25, inside which spiral blades are provided. The discharge valve 23 is located at the outlet end of the spiral sleeve 25.

[0023] In this embodiment, the packaging system further includes a control unit configured to perform the following operations: During the degassing stage, both the feed valve 22 and the discharge valve 23 are kept closed. The negative pressure port 24 is activated to extract air and drive the stirring and extrusion mechanism to stir the material in the degassing chamber to prevent bridging. During the discharge stage, the feed valve 22 is kept closed, the discharge valve 23 is opened, and the spiral blades in the stirring and extrusion mechanism are driven to rotate, so that the degassed material is discharged into the temporary storage bin 3. During the feeding stage, the discharge valve 23 is closed and the feed valve 22 is opened, allowing the material buffered in the feed chute 21 to fall into the degassing chamber.

[0024] The working method of the packaging system in this embodiment specifically includes the following steps: S1, Material Loading Stage: The upstream feeding equipment operates continuously, continuously feeding material into the feed chute 21, closing the discharge valve 23 of the degassing device 2, and opening the feed valve 22 of the degassing device 2, so that the material in the feed chute 21 enters the degassing chamber of the degassing device 2. S2, Degassing stage: Close the feed valve 22 of the degassing device 2 and activate the negative pressure port 24 to generate negative pressure in the degassing chamber. At the same time, start the stirring and extrusion mechanism in the degassing device 2 to stir and agitate the material, making it easier for the gas in the material to be discharged. S3, Discharge Stage: After degassing is completed, open the discharge valve 23 of the degassing device 2 to allow the stirring and extrusion mechanism to continue working and discharge the degassed dense material into the temporary storage bin 3. S4, Replenishment Stage: Close the discharge valve 23 of the degassing device 2, open the feed valve 22 of the degassing device 2, so that the material buffered in the feed chute 21 continues to fall into the degassing chamber of the degassing device 2, return to step S2, and enter the next round of degassing treatment cycle. S5. Packaging: Once a certain amount of material is stored in the temporary storage bin 3, the feeding device 4 can be activated to supply the material in the temporary storage bin 3 to the packaging equipment 5 for bagging.

[0025] The above are only some embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various combinations and modifications of the aforementioned technical features. Any improvements, modifications, equivalent substitutions, or applications of the structure or method of the present invention to other fields to achieve the same effect without departing from the spirit and scope of the present invention shall fall within the protection scope of the present invention.

Claims

1. A packaging system for materials with high gas content and low bulk density, characterized in that... Includes degassing equipment, temporary storage bins, feeding equipment, and packaging equipment; The feed end of the degassing device is connected to the outlet of the upstream feeding equipment, and is used to squeeze and degas the material being conveyed. The inlet of the temporary storage bin is connected to the outlet of the degassing device and is used to temporarily store materials processed by the degassing device. The feed inlet of the feeding device is connected to the outlet of the temporary storage bin, and is used to transfer the materials in the temporary storage bin to the packaging equipment. The packaging equipment is connected to the discharge port of the feeding device and is used to package materials.

2. The packaging system for materials with high gas content and low bulk density according to claim 1, characterized in that: There are multiple degassing devices, with one degassing device corresponding to one or more upstream feeding devices, or one upstream feeding device corresponding to multiple degassing devices.

3. The packaging system for materials with high gas content and low bulk density according to claim 1, characterized in that: The upstream feeding equipment includes an iron separator, and the degassing device is located below the iron separator.

4. The packaging system for materials with high gas content and low bulk density according to claim 1, characterized in that: The degassing device includes a housing with a degassing chamber inside. A negative pressure port is provided on the housing to create a negative pressure in the degassing chamber. A stirring and squeezing mechanism is also provided at the bottom of the degassing chamber to stir and squeeze the material in the degassing chamber, and also has a discharge function.

5. The packaging system for materials with high gas content and low bulk density according to claim 4, characterized in that: The stirring and extrusion mechanism includes a spiral sleeve with spiral blades inside.

6. The packaging system for materials with high gas content and low bulk density according to claim 4, characterized in that: The degassing device also includes a feed chute, which serves to buffer materials; a feed valve is provided at the lower end of the feed chute; and a discharge valve is provided at the outlet end of the mixing and extrusion mechanism.

7. The packaging system for materials with high gas content and low bulk density according to claim 5, characterized in that, It also includes a control unit configured to perform the following operations: During the degassing stage, both the feed valve and the discharge valve are kept closed. The negative pressure interface is activated to extract air and drive the stirring and extrusion mechanism to stir the material in the degassing chamber. During the discharge stage, the feed valve is kept closed, the discharge valve is opened, and the spiral blades in the stirring and extrusion mechanism are driven to rotate; thereby discharging the degassed material into the temporary storage bin. During the feeding stage, the discharge valve is closed and the feed valve is opened, allowing the material in the feed chute to fall into the degassing chamber.

8. A packaging method for materials with high gas content and low bulk density, characterized in that, Includes the following steps: S1, Material Loading Stage: The upstream feeding equipment operates continuously, continuously feeding material into the feed chute. The discharge valve of the degassing device is closed, and the feed valve of the degassing device is opened, allowing the material in the feed chute to enter the degassing chamber of the degassing device. S2, Degassing stage: Close the feed valve of the degassing device and activate the negative pressure interface to generate negative pressure in the degassing chamber. At the same time, start the stirring and extrusion mechanism in the degassing device to stir and agitate the material, making it easier for the gas in the material to be discharged. S3, Discharge Stage: After degassing is completed, open the discharge valve of the degassing device to allow the mixing and extrusion mechanism to continue working and discharge the degassed dense material into the temporary storage bin. S4, Replenishment Stage: Close the discharge valve of the degassing device, open the feed valve of the degassing device, and let the material buffered in the feed chute continue to fall into the degassing chamber of the degassing device. Return to step S2 and enter the next round of degassing treatment cycle. S5. Packaging: Once a certain amount of material has been stored in the temporary storage bin, the feeding device is activated to supply the material in the temporary storage bin to the packaging equipment for bagging.

9. The packaging method for materials with high gas content and low bulk density according to claim 8, characterized in that: There are multiple degassing devices, and the correspondence between the degassing devices and the upstream feeding equipment is many to one or one to many. Each degassing device is independently controlled so as to achieve alternating operation.

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