Equipment for cleaning superfine silver powder

Abstract

The utility model relates to equipment for cleaning superfine silver powder, which comprises a circulating flow channel, a filter pipe and conductivity testing equipment, the circulating flow channel is filled with circularly flowing mixed liquid, at least one filter device is arranged in the filter pipe, the filter device can block silver powder in the mixed liquid, the filter pipe is provided with a liquid inlet and a liquid outlet, and the conductivity testing equipment is connected with the liquid inlet and the liquid outlet. The liquid inlet is used for introducing a detergent, and the liquid outlet is used for discharging part of filtered mixed liquid; and the conductivity testing equipment is arranged at the liquid discharging opening and used for detecting the conductivity of the mixed liquid flowing through the liquid discharging opening, when the conductivity of the mixed liquid reaches a preset value, the liquid discharging opening is closed, and the residual liquid in the circulating flow channel is the cleaned silver powder suspension liquid. The utility model provides equipment for cleaning superfine silver powder, which not only can reduce the use of detergent but also can prevent the superfine silver powder from being accumulated on a filter membrane through circulating cleaning, so that the cleaning efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of ultrafine silver powder cleaning, in particular to a device for cleaning ultrafine silver powder. Background Art

[0002] Due to its specific quantum size effect, surface effect, and excellent electrical conductivity, thermal conductivity, and chemical stability of silver itself, ultrafine silver powder is widely used in various industrial fields. Its production method is mainly the liquid-phase chemical reduction method. In order to control the particle size and distribution of silver powder, various types of polymer protectants and reducing agents are used in the preparation process of silver powder to prevent the agglomeration of the prepared silver powder. This results in a large amount of polymer organic matter and some other ions remaining on the surface of the prepared powder particles, which will have a great impact on the dispersibility and slurry-forming performance of silver powder. Therefore, it is necessary to clean the prepared silver powder to meet commercial use.

[0003] Common silver powder cleaning methods include centrifugation, natural sedimentation, suction filtration, etc. High-speed centrifugation and long-term centrifugation during centrifugal cleaning will cause the silver powder to agglomerate; natural sedimentation for cleaning silver powder takes a long time and the cleaning is not thorough, which is not suitable for industrial cleaning. Suction filtration cleaning generally uses a filter membrane to filter ultrafine silver powder. Traditional suction filtration cleaning methods are all one-way suction filtration cleaning. On the one hand, the detergents used will all be discharged with the wastewater, resulting in waste of detergents. On the other hand, only the silver powder is filtered out during one-way filtration of ultrafine silver powder, which easily causes the silver powder to deposit and block the filter membrane, affecting the suction filtration efficiency. And the silver powder on the filter membrane needs to be cleaned after long-term use, and continuous suction filtration cannot be achieved. Summary of the Utility Model

[0004] Therefore, the technical problem to be solved by the utility model is to overcome the problems of waste of detergents and low suction filtration efficiency caused by suction filtration cleaning of ultrafine silver powder in the prior art, and provide a device for cleaning ultrafine silver powder. Through cyclic cleaning, not only can the use of detergents be reduced, but also the accumulation of ultrafine silver powder on the filter membrane can be prevented, thereby improving the cleaning efficiency.

[0005] To solve the above technical problem, the utility model provides a device for cleaning ultrafine silver powder, including:

[0006] A circulation channel filled with a circulating mixed liquid, the mixed liquid including: a liquid to be cleaned containing ultrafine silver powder and a detergent;

[0007] A filter tube is arranged in the circulation channel. At least one filtering device is arranged in the filter tube. The mixed liquid flows through the filtering device, and the filtering device can block the ultrafine silver powder in the liquid to be cleaned. An inlet and a drain outlet are arranged on the filter tube. Along the flowing direction of the mixed liquid, the inlet and the drain outlet are respectively arranged on both sides of the filtering device. The inlet is used for introducing the detergent, and the drain outlet is used for discharging part of the filtered mixed liquid.

[0008] A conductivity testing device is arranged at the drain outlet and is used for detecting the conductivity of the mixed liquid flowing through the drain outlet. When the conductivity of the mixed liquid reaches a preset value, the drain outlet is closed, and the remaining liquid in the circulation channel is the silver powder suspension after cleaning.

[0009] In an embodiment of the present utility model, a first water pump is arranged in the circulation channel. The first water pump is used for pumping the mixed liquid and pushing the mixed liquid to flow unidirectionally in the circulation channel.

[0010] In an embodiment of the present utility model, it further includes:

[0011] A storage bucket is used for mixing the liquid to be cleaned containing ultrafine silver powder and the detergent. The storage bucket is communicated with the first water pump, and the first water pump pumps the mixed liquid in the storage bucket into the circulation channel. A first valve body for controlling the connection between the two is arranged between the storage bucket and the first water pump.

[0012] A first detergent injection bucket is communicated with the storage bucket, and the first detergent injection bucket can inject the detergent into the storage bucket.

[0013] In an embodiment of the present utility model, it further includes:

[0014] A second valve body is arranged in the circulation channel, and the second valve body can discharge the silver powder suspension after cleaning.

[0015] A silver powder suspension collection box is communicated with the second valve body.

[0016] In an embodiment of the present utility model, it further includes:

[0017] A third valve body is arranged at the drain outlet. The third valve body is in communication connection with the conductivity testing device, and the on-off of the third valve body is controlled by the detection value of the conductivity testing device.

[0018] A waste liquid collection box is communicated with the third valve body.

[0019] In an embodiment of the present utility model, it further includes:

[0020] A second detergent filling bucket, which is communicated with the liquid inlet. A second water pump and a fourth valve body are arranged between the second detergent filling bucket and the filter pipe. The second water pump pumps the detergent in the second detergent filling bucket into the filter pipe, and the fourth valve body controls the on-off between the filter pipe and the second water pump.

[0021] In an embodiment of the present invention, multiple filtering devices are arranged in the filter pipe. Each filtering device has a different filtering level. Along the flowing direction of the mixed liquid, the filtering levels of the multiple filtering devices gradually increase.

[0022] In an embodiment of the present invention, the filtering device is a filter membrane or a filter element.

[0023] In an embodiment of the present invention, the maximum capacity of the circulation channel is 80% of its total volume.

[0024] In an embodiment of the present invention, there are two cleaning modes, which can realize batch cleaning and continuous cleaning.

[0025] The above technical solution of the present invention has the following advantages compared with the prior art:

[0026] The equipment for cleaning ultrafine silver powder of the present invention adopts a circulation channel to realize the mixed circulation flow of the liquid to be cleaned containing ultrafine silver powder and the detergent. A filter pipe is arranged in the circulation channel, and the ultrafine silver powder in the liquid to be cleaned is blocked by the filtering device, and the ultrafine silver powder can be filtered out. During the process of filtering out the ultrafine silver powder, part of the filtered waste liquid is discharged from the circulation channel, and the mixed liquid is continuously supplemented into the circulation channel to ensure that there is sufficient liquid in the circulation channel and it is in a flowing state. Finally, an electrical conductivity testing device is used to judge whether the liquid in the circulation channel is cleaned. The preset value of the electrical conductivity testing device is below 30 μS / cm. At this time, it means that the mixed solution is cleaned, and the remaining liquid in the circulation channel is all the silver powder suspension after cleaning;

[0027] When the circulation channel is arranged to flow in the equipment for cleaning ultrafine silver powder of the present invention, only part of the detergent is discharged through the liquid discharge port, so that the other part of the detergent can continuously clean the liquid to be cleaned containing ultrafine silver powder in the circulation channel. Compared with the prior art's one-way suction filtration cleaning device that discharges all the detergent along with the waste liquid, the use of detergent can be reduced; and compared with the prior art's one-way suction filtration cleaning device that filters out all the ultrafine silver powder, by using the equipment for cleaning ultrafine silver powder of the present invention, it can ensure that the filtered silver powder continuously flows in the detergent, prevent the deposition of ultrafine silver powder in the filtering device, and prevent the filter membrane from being blocked, thereby improving the suction filtration efficiency. Description of the Drawings

[0028] In order to make the content of the present utility model easier to be clearly understood, the following further details the present utility model according to specific embodiments of the present utility model in combination with the drawings, where:

[0029] Figure 1 is a schematic layout diagram of the equipment for cleaning ultrafine silver powder of the present utility model;

[0030] Figure 2 is an electron microscope image of silver powder before cleaning;

[0031] Figure 3 is an electron microscope image of silver powder after being cleaned by the equipment for cleaning ultrafine silver powder of the present utility model.

[0032] Description of the reference numerals in the drawings: 1. Circulation channel; 2. Filter tube; 3. Conductivity testing equipment; 4. First water pump; 5. Storage bucket; 6. First detergent injection bucket; 7. First valve body; 8. Second valve body; 9. Silver powder suspension collection box; 10. Third valve body; 11. Waste liquid collection box; 12. Second detergent injection bucket; 13. Second water pump; 14. Fourth valve body. Detailed Embodiments

[0033] The following further describes the present utility model in combination with the drawings and specific embodiments, so that those skilled in the art can better understand the present utility model and be able to implement it, but the embodiments cited do not limit the present utility model.

[0034] Referring to Figure 1 as shown, the present utility model discloses an equipment for cleaning ultrafine silver powder, including: a circulation channel 1, a filter tube 2 and conductivity testing equipment 3, where: the circulation channel 1 is filled with a mixed liquid, and the mixed liquid includes: a liquid to be cleaned containing ultrafine silver powder and a detergent. A power source is provided in the circulation channel 1 to push the mixed liquid to circulate in the circulation channel 1, so that the liquid to be cleaned containing ultrafine silver powder and the detergent are fully mixed; the filter tube 2 is arranged in the circulation channel 1, the filter tube 2 is docked with the circulation channel 1, and the filter tube 2 is substantially a section of the circulation channel 1. At least one filtering device is arranged in the filter tube 2, and the mixed liquid flows through the filtering device, and the filtering device can block the ultrafine silver powder in the liquid to be cleaned, so that the ultrafine silver powder can be filtered out from the mixed liquid;

[0035] For traditional suction filtration type cleaning equipment, after filtering out the ultrafine silver powder by the filtering device, the entire mixed liquid will be discharged, which will cause waste of the detergent in the mixed liquid. Moreover, the ultrafine silver powder filtered out by the filtering device will be pushed and crowded at the filtering device, resulting in a reduction in the filtering efficiency of the filtering device;

[0036] To solve this problem, the utility model is provided with a liquid inlet and a liquid outlet on the filter tube 2. Along the flowing direction of the mixed liquid, the liquid inlet and the liquid outlet are respectively arranged on both sides of the filtering device. The liquid inlet is used for introducing the detergent, and the liquid outlet is used for discharging a part of the filtered mixed liquid. During the process of filtering out the ultrafine silver powder, a part of the filtered waste liquid is discharged from the circulation channel 1, and the mixed liquid is continuously supplemented into the circulation channel 1 to ensure that there is sufficient liquid in the circulation channel 1 and it is in a flowing state. The conductivity testing device 3 is arranged at the liquid outlet for detecting the conductivity of the mixed liquid flowing through the liquid outlet. When the conductivity of the mixed liquid reaches the preset value, it indicates that the liquid in the circulation channel 1 is cleaned, and the remaining liquid in the circulation channel 1 is all the silver powder suspension after cleaning. By closing the liquid outlet, the silver powder suspension after cleaning can be obtained.

[0037] In this embodiment, during the flowing process of the circulation channel 1, only a part of the detergent is discharged through the liquid outlet, so that the other part of the detergent can continuously clean the liquid to be cleaned containing ultrafine silver powder in the circulation channel 1. Compared with the prior art's unidirectional suction filtration cleaning device that discharges all the detergent along with the waste liquid, the use of the detergent can be reduced; and compared with the prior art's unidirectional suction filtration cleaning device that filters out all the ultrafine silver powder, by using the device for cleaning ultrafine silver powder of the utility model, the detergent is continuously introduced into the filtering device at the liquid inlet, which can ensure that the filtered silver powder continuously flows in the detergent, prevent the deposition of ultrafine silver powder in the filtering device, prevent the filter membrane from being blocked, and thus improve the cleaning efficiency.

[0038] To further prove that the silver powder can be filtered and cleaned by using this device, the morphology of the silver powder before and after washing was characterized by a scanning electron microscope. The morphology of the silver powder before washing is as Figure 2 shown, with a large amount of organic matter residues. The morphology of the silver powder after washing is as Figure 3 shown, without organic matter residues.

[0039] Specifically, in this embodiment, the filtering device is a filter membrane or a filter element. The filtering aperture of the filtering device is determined according to the particle size of the ultrafine silver powder to be cleaned. For example, when cleaning silver powder of micrometers, a filter membrane or a filter element of micrometer level is used; when cleaning silver powder of nanometer level, a filter membrane or a filter element of nanometer level is used.

[0040] Specifically, in an actual device, multiple filtration devices can also be set up. For example, a primary filtration device can be set as a filter membrane or filter element at the micron level first. This primary filtration device can filter silver powder at the micron level and allow silver powder at the nanometer level to pass through. Then, a secondary filtration device can be set to filter silver powder at the nanometer level, thereby achieving the blocking of silver powder at the nanometer level. This can prevent the accumulation of silver powder in a single filtration device and further improve the filtration efficiency. In other embodiments, a tertiary or multi-stage filtration device can be set according to the usage requirements.

[0041] As described above, in order to enable the mixed liquid to flow in the circulation channel 1, a first water pump 4 is provided in the circulation channel 1. The first water pump 4 is used to extract the mixed liquid and push the mixed liquid to flow unidirectionally in the circulation channel 1. Specifically, the power of the first water pump 4 is controlled according to the actual situation to control the flow rate of the mixed liquid in the circulation channel 1.

[0042] Refer to Figure 1 As shown, when in actual use, the device for cleaning ultrafine silver powder of the present invention can be divided into a feeding part, a circulation part, a silver powder suspension collection part, a waste liquid discharge part, and a feeding supplement part. The circulation channel 1, the filter tube 2, and the conductivity testing device 3 are the circulation part of this device. In order to further improve the device of the present invention, the devices of the feeding part, the feeding supplement part, the silver powder suspension collection part, and the waste liquid discharge part will be described below.

[0043] Specifically, the feeding part further includes a storage bucket 5 and a first detergent injection bucket 6. Among them: the storage bucket 5 is used to mix the liquid to be cleaned containing ultrafine silver powder and the detergent. The storage bucket 5 is connected to the first water pump 4. The first water pump 4 pumps the mixed liquid in the storage bucket 5 into the circulation channel 1. A first valve body 7 for controlling the connection between the two is provided between the storage bucket 5 and the first water pump 4. When the first valve body 7 is opened, the first water pump 4 is set to be able to continuously extract the mixed liquid from the storage bucket 5. The first detergent injection bucket 6 is connected to the storage bucket 5, and the first detergent injection bucket 6 can inject the detergent into the storage bucket 5.

[0044] In the actual operation process, setting the ratio of the liquid to be cleaned containing ultrafine silver powder to the detergent as 1:1 can ensure the cleaning quality.

[0045] Specifically, the silver powder suspension collection part further includes: a second valve body 8 disposed in the circulation channel 1 and a silver powder suspension collection tank 9 communicated with the second valve body 8. When filtering the mixed solution, the second valve body 8 can communicate with the circulation channel 1 to ensure the flow of the mixed liquid in the circulation channel 1. After the filtering of the mixed solution is completed, when all the remaining liquid in the circulation channel 1 is the washed silver powder suspension, the second valve body 8 is opened, and the washed silver powder suspension in the circulation channel 1 can flow into the silver powder suspension collection tank 9 through the second valve body 8 and be stored in the silver powder suspension collection tank 9. At this time, the washed silver powder suspension does not contain other ions and high-molecular organic substances.

[0046] Specifically, the waste liquid discharge part further includes: a third valve body 10 and a waste liquid collection tank 11 communicated with the third valve body 10. The third valve body 10 is disposed at the liquid discharge port, and the third valve body 10 is communicatively connected to the conductivity testing device 3. The on / off of the third valve body 10 is controlled by the detection value of the conductivity testing device 3. When filtering the mixed solution, the third valve body 10 is in a continuously open state, and the waste liquid continuously discharges from the third valve body 10 and enters the waste liquid collection tank 11. When the conductivity testing device 3 detects that the conductivity of the mixed liquid reaches a preset value, the third valve body 10 changes to a closed state, and the liquid discharge port is closed through the third valve body 10.

[0047] In this embodiment, the preset value of the conductivity testing device 3 is below 30 μS / cm, which indicates that the mixed solution is cleaned.

[0048] Specifically, the liquid supplement part further includes: a second detergent injection barrel 12 communicated with the liquid inlet. A second water pump 13 and a fourth valve body 14 are disposed between the second detergent injection barrel 12 and the filter tube 2. When filtering the mixed solution, the second water pump 13 and the fourth valve body 14 are opened, and the second water pump 13 pumps the washing solution in the second detergent injection barrel 12 into the filter tube 2. After the filtering of the mixed solution is completed, the second water pump 13 and the fourth valve body 14 are closed.

[0049] In this embodiment, the detergents in the first detergent injection barrel 6 and the second detergent injection barrel 12 have the same composition, and the detergent can be: deionized water, ethanol, or a mixture of deionized water and ethanol.

[0050] In this embodiment, the first valve body 7, the second valve body 8, the third valve body 10, and the fourth valve body 14 are all three-way solenoid valves, and the switching of the connection state of the valve body can be realized through electric control.

[0051] Specifically, to further illustrate the equipment for cleaning ultrafine silver powder of the present utility model, the usage process of the equipment is disclosed in this embodiment:

[0052] (1) Inject the liquid to be cleaned containing ultrafine silver powder into the storage bucket 5. At the same time, inject detergent into the storage bucket 5 through the first detergent feeding bucket 6, and fully mix the liquid to be cleaned containing ultrafine silver powder and the detergent in the storage bucket 5;

[0053] (2) Open the first valve and the first water pump 4, and connect the second valve to the circulation channel 1, introducing the mixed liquid in the storage bucket 5 into the circulation channel 1. When the volume of the mixed liquid in the circulation channel 1 reaches 80% of the total volume, close the first valve and no longer introduce the mixed liquid into the circulation channel 1. At this time, continuously open the first water pump 4 to make the mixed liquid flow in the circulation channel 1;

[0054] It should be noted that the maximum capacity of the mixed liquid in the circulation channel 1 is set to 80%. While introducing as much mixed liquid as possible, it ensures the full mixing of the liquid to be cleaned and the detergent, and also ensures the safety of the circulation channel 1 during use. If the added mixed liquid is too full, it is easy to cause excessive pressure in the circulation channel 1 and damage the circulation channel 1.

[0055] (3) Open the second water pump 13, the third valve and the fourth valve, and continuously introduce detergent into the circulation channel 1 through the second water pump 13. On the one hand, it is a supplement to the detergent in the mixed liquid. On the other hand, it can also wash the filtration device with the detergent to prevent the filtered silver powder from depositing on the filtration device and causing blockage of the filtration device; at the same time, open the third valve to discharge part of the filtered waste liquid;

[0056] (4) Continuously detect the conductivity of the solution discharged from the circulation channel 1 through the conductivity tester. When the conductivity is lower than the preset value, that is, below 30 μS / cm, after closing the third valve, the fourth valve and the second water pump 13, then close the first water pump 4, and open the second valve downward to connect the second valve to the silver powder suspension collection box 9, and discharge the cleaned silver powder suspension from the pipeline.

[0057] It should be noted that the equipment in this embodiment has two cleaning modes:

[0058] The cleaning mode of batch processing can be adopted, that is, after all the above steps (1) to (4) are completed, re-inject the liquid to be cleaned containing ultrafine silver powder and the detergent into the storage bucket 5;

[0059] In the cleaning mode that can adopt continuous processing, since part of the filtered waste liquid is discharged in step (3), while discharging the waste liquid, the first valve can be opened to continuously introduce the mixed liquid into the circulation channel 1, thereby realizing continuous cleaning and further improving the cleaning efficiency.

[0060] Obviously, the above embodiments are only examples clearly described and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the creation of the present utility model.

Claims

1. An apparatus for cleaning ultrafine silver powder, characterized in that, Including: A circulation channel filled with a mixed liquid flowing in a cycle. The mixed liquid includes a cleaning liquid to be cleaned containing ultrafine silver powder and a detergent. A filter tube is disposed in the circulation channel. At least one filtering device is provided inside the filter tube. The mixed liquid flows through the filtering device, and the filtering device can block the ultrafine silver powder in the cleaning liquid to be cleaned. An inlet and a drain port are provided on the filter tube. Along the flowing direction of the mixed liquid, the inlet and the drain port are respectively disposed on both sides of the filtering device. The inlet is used for introducing the detergent, and the drain port is used for discharging a part of the mixed liquid after cleaning. A conductivity testing device is disposed at the drain port for detecting the conductivity of the mixed liquid flowing through the drain port. When the conductivity of the mixed liquid reaches a preset value, the drain port is closed, and the remaining liquid in the circulation channel is the silver powder suspension after cleaning.

2. The equipment for cleaning ultrafine silver powder according to claim 1, characterized in that: A first water pump is disposed in the circulation channel. The first water pump is used for pumping the mixed liquid and pushing the mixed liquid to flow unidirectionally in the circulation channel.

3. The device for cleaning ultrafine silver powder according to claim 2, characterized in that: Further including: A storage bucket for mixing the cleaning liquid to be cleaned containing ultrafine silver powder and the detergent. The storage bucket is communicated with the first water pump. The first water pump pumps the mixed liquid in the storage bucket into the circulation channel. A first valve body for controlling the communication between the two is disposed between the storage bucket and the first water pump. A first detergent injection bucket is communicated with the storage bucket, and the first detergent injection bucket can inject the detergent into the storage bucket.

4. The equipment for cleaning ultrafine silver powder according to claim 1, characterized in that: Further including: A second valve body is disposed in the circulation channel, and the second valve body can discharge the silver powder suspension after cleaning. A silver powder suspension collection box is communicated with the second valve body.

5. The equipment for cleaning ultrafine silver powder according to claim 1, characterized in that: Further including: A third valve body is disposed at the drain port. The third valve body is in communication connection with the conductivity testing device, and the on-off of the third valve body is controlled by the detection value of the conductivity testing device. A waste liquid collection box is communicated with the third valve body.

6. The equipment for cleaning ultrafine silver powder according to claim 1, characterized in that: Further including: A second detergent injection bucket is communicated with the inlet. A second water pump and a fourth valve body are disposed between the second detergent injection bucket and the filter tube. The second water pump pumps the detergent in the second detergent injection bucket into the filter tube, and the fourth valve body controls the on-off between the filter tube and the second water pump.

7. The equipment for cleaning ultrafine silver powder according to claim 1, characterized in that: Multiple filtering devices are provided in the filter tube, and the filtering grades of each filtering device are different. Along the flowing direction of the mixed liquid, the filtering grades of the multiple filtering devices gradually increase.

8. The equipment for cleaning ultrafine silver powder according to claim 7, characterized in that: The filtering device is a filter membrane or a filter element.

9. The equipment for cleaning ultrafine silver powder according to claim 1, characterized in that: The maximum capacity of the circulation channel is 80% of its total volume.

10. The equipment for cleaning ultrafine silver powder according to claim 1, characterized in that: It has two cleaning modes and can achieve batch cleaning and continuous cleaning.

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