KR20220087050A - System for conveying electrode slurry - Google Patents

Abstract

The present invention relates to an electrode slurry transfer system for transferring an electrode slurry from a mixer in which the electrode slurry is mixed to a coater for coating the electrode slurry, comprising: a mixer storage tank into which the electrode slurry is introduced from the mixer; a coater transfer tank connected to the mixer storage tank by a first pipe; and a coater supply tank connected to the coater transfer tank by a second pipe and supplying the electrode slurry supplied from the coater transfer tank to the coater; Including, wherein the coater transfer tank has a natural vent unit connected to the external atmosphere and a forced vent unit fluidly connected to the A/C tower, and while the air in the coater transfer tank is forcibly exhausted through the forced vent unit, the Fluid communication between the natural vent and the outside atmosphere is blocked.

Description

Electrode slurry transfer system {SYSTEM FOR CONVEYING ELECTRODE SLURRY}

The present invention relates to an electrode slurry transfer system for transferring the electrode slurry from a mixer in which the electrode slurry is mixed to a coater for coating the electrode slurry on a current collector.

More particularly, it relates to an electrode slurry transport system including a mixer storage tank, a coater transport tank, and a coater supply tank, which can significantly reduce the amount of air bubbles introduced during transport of the electrode slurry supplied to the coater.

With the increase in technology development and demand for mobile devices, the demand for secondary batteries is also rapidly increasing. Among them, a lithium secondary battery is widely used as an energy source for various electronic products as well as various mobile devices in that it has high energy density and operating voltage and excellent preservation and lifespan characteristics.

A lithium secondary battery includes a pair of electrodes, a positive electrode and a negative electrode, and a separator and an electrolyte that insulate between them. Each of the positive electrode and the negative electrode, which are electrodes of a secondary battery, is manufactured by applying an electrode slurry to the surface of a current collector made of an aluminum or copper thin plate, processing a tab on an electrode substrate that has undergone a drying process, and cutting it to an appropriate size. The electrode slurry is prepared as an electrode substrate by applying a solvent, an active material, a conductive material, a binder, etc. to the surface of the current collector in a mixed form. For example, the electrode slurry (paste) is prepared by mixing the active material and other solids, and then kneading the obtained mixed powder with a dispersion medium such as NMP or water.

The electrode slurry is mixed with the components in a predetermined mixer, and then moved to the mixer storage tank, passed through the coater transfer tank, and then to the coater supply tank, and then supplied to a coating die (coater) to be coated on the current collector. These electrode slurries usually contain air bubbles during manufacturing and transport. If the electrode slurry containing air bubbles is applied on the current collector as it is, the active material is not applied to the area of the air bubbles, resulting in a defect. This defect is called a pinhole, and the pinhole may cause dendrite formation during battery charging, thereby affecting battery safety. Alternatively, a defect in the shape of a crater may be formed on the electrode as the bubble bursts during coating.

The reasons for the introduction of air bubbles from the electrode slurry line to the mixer storage tank, the coater transfer tank, the coater supply tank and the coater are as follows.

First, the length of the pipe transferred from the mixer storage tank to the coater transfer tank is long, and since this pipe is an open system through which air flows, the air introduced into the pipe flows into the coater transfer tank together with the slurry when the slurry is transferred to the slurry. create air bubbles in

Second, when the slurry is introduced into the coater transfer tank, when the slurry falls on the bottom of the tank, air is introduced into the slurry by impact to generate bubbles.

Third, when pigs are put into the piping for the discharge of residual slurry in the piping connecting the mixer storage tank and the coater transfer tank at the last production point, a large amount of air due to the compressed air (about 5 bar) used to push the pigs out is introduced with the slurry to generate bubbles.

Meanwhile, in the prior art, a depackaging device was installed to remove air bubbles flowing into the coater transfer tank and the like. The degassing device is connected by a vacuum pump and a pipe to vacuum suction and discharge air bubbles from the electrode slurry in the degassing device. However, if the packaging device is installed, the manufacturing cost increases. In addition, when the degassing device is installed in the tank, it is necessary to stop the transfer of the electrode slurry for the operation of the degassing device, which causes a floating state of the production line, thereby lowering productivity.

From the above, in the electrode slurry transport system, development of a transport system capable of blocking the inflow of bubbles is desired. In addition, it is desired to develop a technology capable of effectively preventing the inflow of air bubbles into the electrode slurry without installing a separate degassing device and preventing the occurrence of a floating state in the production line.

Republic of Korea Patent Publication No. 10-2017-0087124

The present invention was made to solve the above problems, and an object of the present invention is to provide an electrode slurry transport system capable of preventing the inflow of bubbles during transport of the electrode slurry from the mixer to the coater and effectively removing the generated bubbles.

In addition, another object of the present invention is to provide an electrode slurry transport system capable of effectively removing air mixed in when pigs are introduced into a pipe for removing residual slurry.

In addition, the present invention provides a transfer system capable of reducing the generation of air bubbles due to the drop of the electrode slurry in the coater transfer tank.

In order to solve the above problems, the electrode slurry transport system of the present invention is an electrode slurry transport system for transporting the electrode slurry from a mixer in which the electrode slurry is mixed to a coater for coating the electrode slurry, the electrode slurry is introduced from the mixer mixer storage tank; a coater transfer tank connected to the mixer storage tank by a first pipe; and a coater supply tank connected to the coater transfer tank by a second pipe and supplying the electrode slurry supplied from the coater transfer tank to the coater; Including, wherein the coater transfer tank has a natural vent unit connected to the external atmosphere and a forced vent unit fluidly connected to the A/C tower, and while the air in the coater transfer tank is forcibly exhausted through the forced vent unit, the It is characterized in that fluid communication between the natural vent part and the external atmosphere is blocked.

As an example, by maintaining the inside of the coater transfer tank in a weak vacuum state by the forced exhaust by the forced vent unit, air in the coater transfer tank may be forcibly exhausted even during the transfer of the electrode slurry.

Specifically, in the weak vacuum state, it is preferable that the differential pressure between the coater transfer tank and the external atmosphere is less than -20pa.

The weak vacuum state may be adjusted by adjusting the opening rate of the valve installed in the pipe connecting the forced vent unit and the A/C tower.

As an embodiment, a check valve for preventing backflow of air may be installed in at least one of an adjacent part of the coater transfer tank of the first pipe and an adjacent part of the coater supply tank of the second pipe.

As an example, the coater transfer tank further includes a vacuum pump connection unit connected to a vacuum pump, and the vacuum pump may be operated in an emergency when a large amount of bubbles in the tank are generated to stop the system operation.

As a specific example, the natural vent part and the vacuum pump connection part are formed in the same opening on the coater transfer tank, and the pipe connected to the opening is a first branch pipe connected to the external atmosphere and a first branch pipe connected to the vacuum pump. It can be branched into a two-branch pipe.

After the operation of the vacuum pump is terminated, the natural vent unit and the external atmosphere may be in fluid communication with the natural vent unit to increase the internal pressure of the coater transfer tank for transferring the electrode slurry before the system is restarted.

As an example, when the introduction of the electrode slurry from the mixer storage tank to the first pipe is stopped and pigs are introduced into the first pipe to remove the residual slurry in the first pipe, the vacuum pump may be operated.

As an embodiment, a return pipe returning to the coater transfer tank may be branched from the second pipe, and a 3-way valve may be installed at a branch of the second pipe and the return pipe.

As another embodiment, the first pipe may extend into the coater transport tank, and the end of the first pipe extending into the coater transport tank may be configured to discharge the electrode slurry toward the inner wall surface of the coater transport tank. .

As a specific example, the end of the first pipe may be bent toward the inner wall surface of the coater transfer tank.

As another example, the extension portion of the first pipe into the coater transfer tank may extend along the inner circumferential surface of the coater transfer tank, and the opening at the end of the extension may be opened toward the inner wall surface of the coater transfer tank.

Specifically, the extension portion of the first pipe into the coater transfer tank may be installed horizontally in the coater transfer tank. Alternatively, the extension portion of the first pipe into the coater transfer tank may be installed to be inclined downward of the coater transfer tank.

As an example, the extension of the first pipe into the coater transfer tank may be formed to have a larger diameter toward the opening of the end of the extension.

As a more specific example, the extension of the first pipe to the inside of the coater transfer tank forms a bifurcated pipe from the first pipe, and the branched pipe extends along the inner circumferential surface of the coater transport tank in opposite directions. it may be

As an example, the return pipe returning to the coater transfer tank extends into the coater transfer tank, and the end of the return pipe extending into the coater transfer tank is configured to discharge the electrode slurry toward the inner wall surface of the coater transfer tank can be

As a specific example, the end of the return pipe may be bent toward the inner wall surface of the coater transfer tank.

According to the present invention, it is possible to reduce the occurrence of defects in the shape of pinholes or craters on the coating electrode by reducing the inflow of air bubbles when transferring the electrode slurry from the mixer to the coater.

In addition, according to the present invention, it is possible to effectively remove the air mixed when the pig is introduced into the pipe for removing the residual slurry.

In addition, the present invention can reduce the generation of bubbles due to the drop of the electrode slurry in the coater transfer tank.

1 is a schematic diagram of a conventional electrode slurry transport system.
Figure 2 is a schematic view showing a process of removing the residual slurry by putting the pig in the pipe.
3 is a schematic diagram of an electrode slurry conveying system according to a first embodiment of the present invention.
4 is a schematic diagram of an electrode slurry conveying system according to a second embodiment of the present invention.
It is a perspective view which shows the inside of the coater transfer tank of 2nd Embodiment.
It is a perspective view which shows the inside of the coater transfer tank of the modified example of 2nd Embodiment.

Hereinafter, the detailed configuration of the present invention will be described in detail with reference to the accompanying drawings and various embodiments. The embodiments described below are illustratively shown to aid understanding of the present invention, and the accompanying drawings are not drawn to scale to aid understanding of the present invention, and dimensions of some components may be exaggerated. .

Since the present invention can have various changes and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

1 is a schematic diagram of a conventional electrode slurry transport system 100 . In FIG. 1 , the dotted arrow indicates the flow of air, the solid arrow indicates the flow of the slurry, and the thick arrow indicates the input and discharge of the pig.

The electrode slurry is introduced from a mixer (not shown) into the mixer storage tank 10 , and the electrode slurry is pumped by the pump P1 and introduced into the coater transfer tank 20 through the first pipe 50 . The coater transfer tank 20 is a tank serving as a kind of buffer tank before transferring the electrode slurry from the mixer storage tank 10 to the coater supply tank 30 . Since the coater supply tank 30 has a small capacity, a coater transfer tank 20 with a larger capacity is required. The coater transfer tank 20 and the coater supply tank 30 are connected by a second pipe 60 , and the electrode slurry of the coater transport tank 20 is pumped by the pump P2 through the second pipe 60 . It is supplied to the coater supply tank (30). The electrode slurry introduced from the coater supply tank 30 is transferred to the coater 40 through the coater connection pipe 70 so that the electrode slurry is coated on the electrode current collector.

The coater transfer tank 20 is provided with a natural vent part 23 on the upper portion of the transfer tank to maintain the pressure inside the coater transfer tank at atmospheric pressure. That is, the natural vent unit is an air inlet and outlet connected to the external atmosphere. The air inlet and outlet are connected to the outside atmosphere by a third pipe 80 . In some cases, the third pipe 80 may extend into the coater transfer tank 20 . In this case, the third pipe part extending into the coater transfer tank becomes the natural vent part 23 .

In addition, the coater transfer tank 20 is provided with a vacuum pump connection for removing the air bubbles when a large amount of air bubbles in the tank are generated. That is, the vacuum pump connection part is an air inlet and outlet connected to the vacuum pump VP.

The natural vent part and the vacuum pump connection part may be separately formed on the coater transfer tank, or may be formed through the same opening 23 . That is, the third pipe 80 is connected to the same opening 23 on the coater transfer tank, and one branch pipe is connected to the external atmosphere by branching the third pipe 80, and the other is a vacuum pump ( VP), it is possible to achieve both natural venting and forced venting with a vacuum pump with one opening 23 .

The conventional coater transfer tank 20 opens the valve 85 on the pipe connected to the external atmosphere during operation of the system in which the electrode slurry is transferred to enable fluid communication to the natural vent, thereby reducing the inside of the transfer tank 20 to atmospheric pressure. are maintaining If bubbles are generated in a large amount in the coater transfer tank 20, stop the operation of the system (that is, stop transferring the electrode slurry), close the pipe 81 connected to the external atmosphere, and use the vacuum pump (VP) is operated to perform a forced venting process for vacuum suction of air bubbles from the coater transfer tank 20 .

However, since the valve 85 is opened as described above during system operation and fluid communication from the natural vent part to the external atmosphere is possible, the mixer storage tank 10 - the first pipe 50 - the coater transfer tank 20 The fluid movement path becomes an open system, and the air introduced into the first pipe 50 flows into the coater transfer tank together with the slurry when the slurry is transferred to generate bubbles. In addition, when the pressure in the coater transfer tank 20 fluctuates and becomes less than atmospheric pressure, air flows into the coater transfer tank 20 through the natural vent unit 23 to generate bubbles in the slurry as well. Since the first pipe 50 is relatively long, the amount of air introduced into the first pipe 50 may be large in the open system as described above.

In addition, in the conventional coater transfer tank 20, when the electrode slurry is input from the first pipe 50 to the coater transfer tank, it has a structure that directly falls from the upper part of the tank to the lower part of the tank, so that bubbles are also generated in this process. do. That is, the first pipe 50 is connected to the inlet installed in the coater transfer tank 20 so that the electrode slurry falls into the tank from the inlet, or, as shown in FIG. 1 , the first pipe 50 is the coater As a structure in which the electrode slurry extends into the transfer tank and falls into the tank from the end of the extended pipe 51, it was a structure in which bubble generation due to the slurry drop was unavoidable.

In addition, this problem of electrode slurry dropping in the tank also occurred in the electrode slurry circulation line. That is, the electrode slurry discharged from the coater transfer tank 20 is pumped by the pump P2 and transferred to the coater supply tank 30 through the second pipe 60 , but in the coater supply tank 30 more than the set value. When the slurry is supplied, the slurry supply to the coater supply tank 30 is cut off by the 3-way valve 63 , and the electrode slurry is returned to the coater transfer tank 20 again through the return pipe 62 . That is, in this case, the pipe (the first partial pipe 61) and the return pipe 62 from the coater transfer tank 20 to the 3-way valve form an electrode slurry circulation line. Since the electrode slurry fed into the coater transfer tank 20 from the return pipe 62 also fell directly to the bottom of the tank, bubbles were inevitably generated.

Figure 2 is a schematic view showing a process of removing the residual slurry by putting the pig (1) in the pipe.

The pig 1 is a member for discharging water or oil remaining in the pipe to the outside. As shown in FIGS. 2(a) and (b), high-pressure compressed air 8 is generated from a pig launcher 6 using an air compressor 4, and the compressed air generated at this time is pressurized. When the pig 1 inserted into the pipe 5 is pressurized using a fluid, the pig moves along the inside of the pipe to remove water or oil remaining in the pipe. The pig is discharged from the pipe (5) and accommodated in the pig receiver (7). However, as shown in Fig. 2(b), when the compressed air 8 leaks to the front of the pig through the gap between the inner peripheral surface of the pig 1 and the pipe 5, the air 8 ′ flows into the front pipe of the pig. can be

Fig. 1 shows that the pigs 1 and 50 are input and discharged into and out of the first pipe 50 by the input pipe 2 and the discharge pipe 3 connected to the first pipe. In FIG. 1, the pig 1 is input and discharged at a right angle to the first pipe 50, and the input pipe 2 and the discharge pipe 3 are shown to be smaller than the diameter of the pig, but this is for convenience of illustration. In fact, the diameters of the input pipe 2 and the discharge pipe 3 are larger than the pig 1 as shown in FIG. It is connected to the first pipe (50). However, in the present specification, since the shapes of the input pipe 2 and the discharge pipe 3 are not essential, they are only schematically illustrated as in FIG. 1 , and detailed description thereof will also be omitted.

The introduction of the pig 1 in the electrode slurry transport system 100 is the last step in product production for removing the residual slurry remaining in the first pipe 50 when the introduction of the slurry from the mixer storage tank 10 is stopped. In this case, due to the compressed air of high pressure (about 5 bar) used to push the pig 1, a large amount of air is introduced together with the slurry to generate bubbles.

As described above, in the conventional electrode slurry transport system 100 including the mixer storage tank 10 , the coater transport tank 20 and the coater supply tank 30 , air bubbles are mixed into the electrode slurry for various reasons, and thereby the coater In (40), when the electrode slurry is applied to the current collector, pinholes or crater shape defects may occur.

In order to solve this problem, the present invention blocks the natural vent during operation of the device for transferring the electrode slurry, unless there is a special reason, so that the fluid transfer path to the mixer storage tank - the first pipe - the coater transfer tank is configured as a closed system And, by discharging the air flowing in through the mixer storage tank and the first pipe or the air generated in the coater transfer tank through a forced vent unit separate from the vacuum pump, it is possible to effectively suppress the generation of bubbles in the coater transfer tank. characterized by having Since the forced vent unit is in fluid connection with the A/C tower (adsorption tower) separately installed in the battery manufacturing plant, the coater transfer tank can be forcibly exhausted at all times by the weak vacuum pressure applied from the A/C tower. In this case, when the valve of the pipe connected to the natural vent is closed so that fluid communication with the external atmosphere is blocked through the natural vent, the introduction of air from the external atmosphere to the natural vent can be blocked.

The more detailed configuration of the present invention described above will be described in more detail with reference to the accompanying drawings and embodiments. In the following description, the same components as those of the prior art will be described with the same reference numerals.

(First embodiment)

3 is a schematic diagram of an electrode slurry transport system 200 according to a first embodiment of the present invention.

In this embodiment, as in the conventional electrode slurry transfer system, the mixer storage tank 10 - the first pipe 50 - the coater transfer tank 20 - the second pipe 60 - the coater supply tank 30 - the coater connection The electrode slurry is transferred to the pipe 70-coater 40 . The mixer storage tank 10 , the coater transfer tank 20 , and the coater supply tank 30 include driving motors 11 , 21 , 31 and stirring members 12 , 22 , and 32 driven by the driving motor, respectively. are being prepared Since the electrode slurry is a relatively high-viscosity, high-viscosity fluid of approximately 1000 to 5000 cp, stirring by a stirring member is required during the transfer process.

In addition, the first pipe 50 between the mixer storage tank 10 and the coater transport tank 20 and the second pipe 60 of the coater transport tank 20 and the coater supply tank 30 have pumps P1, P2) is installed so that the electrode slurry can be pumped and transported.

A 3-way valve 63 is installed in the second pipe 60 , and a return pipe 62 is branched from the second pipe 60 in the portion where the 3-way valve 63 is installed. That is, the second pipe (first partial pipe 61) from the coater transfer tank 20 to the 3-way valve 63 and the return pipe 62 form an electrode slurry circulation line. The remaining portion of the second pipe (the second partial pipe 64 ) is connected to the coater supply tank 30 .

When the electrode slurry is filled in the coater supply tank 30 to less than the first set value (for example, 30% of the coater supply tank is filled), the controller controls the 3-way valve 63 to transfer the electrode slurry to the coater supply tank 30 . to control In this case, the electrode slurry discharged from the coater transfer tank 20 is transferred to the coater supply tank 30 through the first partial pipe 61 and the second partial pipe 64 .

On the other hand, when the electrode slurry of the coater supply tank 30 is filled in excess of the second set value (eg, 50% of the coater supply tank), the control unit controls the 3-way valve 63 to The discharged electrode slurry is returned to the coater transfer tank 20 through the first partial pipe 61 and the return pipe 62 .

A pump (P2) and a filter (F) are installed in the first partial pipe (61).

The coater transfer tank 20 of the present invention is provided with a natural vent unit 23 connected to the external atmosphere in the same way as in the conventional electrode slurry transfer system, but in addition to this, a forced vent unit fluidly connected to the A/C tower ( 24) distinguishes it from the conventional system. In the present invention, the forced vent unit 24 is always open during operation of the system to which the electrode slurry is transferred, so that air in the coater transfer tank 20 is forcibly exhausted through the forced vent unit 24, but the natural vent unit 23 ) and the external atmosphere are blocked during the forced exhaust. That is, during forced exhaust, the valve 85 of the pipe connected to the natural vent part 23 is closed to prevent the inflow of external air through the natural vent part 23 .

The natural vent unit 23 may be an air inlet and outlet at the top of the coater transfer tank connected to the external atmosphere, or when the pipe connected to the external atmosphere extends into the coater transfer tank, it will be a natural vent unit including the extension. can

The forced vent unit 24 may be an air inlet and outlet of the upper portion of the coater transfer tank 20 connected to an A/C tower (not shown) by a connecting pipe 90 . Although not shown in FIG. 3 , when the pipe 90 connected to the A/C tower extends into the coater transfer tank 20 , it may be a forced vent part including the extension part.

When the inside of the coater transfer tank 20 is maintained in a weak vacuum state due to the forced exhaust by the forced vent unit 24 , the air in the coater transfer tank 20 can be continuously forcedly exhausted even during the transfer of the electrode slurry. In order to maintain a weak vacuum state, as described above, the natural vent part 23 is blocked. If the vacuum suction by the forced vent unit 24 is made with too strong vacuum pressure, the transfer of the electrode slurry may become difficult, so the inside of the coater transfer tank formed by the forced vent unit 24 connected to the A/C tower It is sufficient that the vacuum state of In the weak vacuum state, it is preferable that the differential pressure between the coater transfer tank 20 and the external atmosphere is less than -20pa. In a state of such a weak vacuum, the air in the coater transfer tank 20 can be effectively exhausted without interfering with the movement of the electrode slurry. The weak vacuum state can be achieved by adjusting the opening rate of the valve (not shown) installed in the pipe (A/C tower connection pipe 90) connecting the forced vent unit 24 and the A/C tower. have.

Meanwhile, in another embodiment of the present invention, check valves 55 and 65 for preventing backflow of air may be installed in the first pipe 50 and/or the second pipe 60 . Since the electrode slurry has a high viscosity and is supplied from the mixer storage tank 10 to the coater supply tank 30 at a strong pressure by pumping the pump, the reverse flow of the slurry in the first and second pipes hardly occurs. Therefore, in principle, the check valve 60 for preventing the slurry backflow is not required in the first pipe 50 and the second pipe to which the slurry is transferred. However, in the coater transfer tank 20 or the coater supply tank 30, bubbles may be generated in the tank by the slurry dropping or by stirring by the stirring member, and the bubbles are generated in the first pipe 50 or the second pipe. (60) can be reversed.

Therefore, in this embodiment, check valves 55 and 65 are installed in at least one of the first pipe part adjacent to the coater transfer tank 20 and the second pipe part adjacent to the coater supply tank 30 . This prevents air from flowing back into the pipes.

As described above, in the present invention, the air flowing in from the first pipe 50, etc. is always exhausted by the forced vent unit 24, and the air flowing back from the coater transfer tank 20, etc. is to the check valve 55. to block the inflow of air from the natural vent unit 23, so that the inflow of air bubbles from the coater transfer tank 20 and the coater supply tank 30, and air bubbles into the first and second pipes 50 and 60 to prevent ingress. That is, the fluid communication to the forced vent part 24, the fluid blockage to the natural vent part 23, and the configuration of the check valve 55 are organically combined to implement an electrode slurry transport system that can suppress bubble generation as much as possible, and have.

On the other hand, in the present invention also provided with a vacuum pump connection for removing the bubbles when a large amount of bubbles in the tank are generated. The vacuum pump connection part is an air inlet and outlet connected to the vacuum pump. The difference between the forced vent part 24 connected to the A/C tower of the present invention and the vacuum pump connection part is that the former is operated and forced to exhaust even during slurry transfer, but the latter is the slurry only in abnormal or emergency situations when a large amount of bubbles are generated. It is said that it is a movable part in an emergency situation that stops movement and is opened.

In order to simplify the device configuration, it is preferable that the natural vent part 23 and the vacuum pump connection part have the same opening 23 on the coater transfer tank. As shown in Fig. 3, the third pipe 80 is connected to the same opening 23 on the transfer tank, and the third pipe is branched so that one of the branch pipes (the first branch pipe 81) is connected to the external atmosphere. When connected and another branch pipe (second branch pipe 82) is connected to the vacuum pump, both natural venting and forced venting to the vacuum pump can be achieved with one opening.

The natural vent part 23 is closed during the operation of the slurry transfer system or in an emergency when fluid communication to the vacuum pump VP is opened. That is, the conventional natural vent part was always opened to maintain the inside of the coater transfer tank at atmospheric pressure, but in the present invention, in principle, fluid communication with the external atmosphere is always blocked. When the valve 85 installed in the first branch pipe 81 is opened so that the natural vent part 23 and the external atmosphere are in fluid communication with each other, it is after the operation of the vacuum pump VP is finished. That is, when the vacuum pump VP is operated to evacuate the coater transfer tank 20 in an emergency, the coater transfer tank is in a high vacuum state of approximately -1 bar. In order to transfer the electrode slurry into or out of the coater transfer tank 20 , this high vacuum state must be resolved, so it is necessary to quickly increase the internal pressure of the coater transfer tank 20 . At this time, when the natural vent part 23 is opened to communicate the coater transfer tank 20 with the external atmosphere, the internal pressure of the coater transfer tank is increased to be in a state in which the electrode slurry can be transferred. In this state, the system may be restarted to transfer the electrode slurry to the coater 40 .

On the other hand, as described above, since the vacuum pump VP applies a high vacuum to the coater transfer tank 20, it is not operated during electrode slurry transfer, and when the system is stopped in an emergency situation in which a large amount of air bubbles are generated in the tank is activated

In the electrode slurry transport system according to an embodiment of the present invention, the vacuum pump VP is operated even when the pig 1 is input. That is, when the introduction of the slurry from the mixer storage tank 10 to the first pipe 50 is stopped and the remaining amount of the slurry remains only in the first pipe 50, the pig 1 as shown in FIG. is introduced into the first pipe. At this time, strong compressed air of 5 bar is injected for pig input, and thus a large amount of air is introduced into the first pipe 50. By operating the vacuum pump VP, the large amount of air is transferred to the coater transfer tank 20 ) can be released from Therefore, according to this embodiment, it is possible to prevent air from flowing into the slurry even when the pig 1 is introduced into the first pipe 50 . At this time, the fluid communication through the natural vent part 23 and the forced vent part 24 to the A/C tower may inhibit the vacuum exhaust to the vacuum pump VP, so it is preferable to be blocked.

(Second embodiment)

4 is a schematic diagram of an electrode slurry transport system 300 of a second embodiment of the present invention, and FIG. 5 is a perspective view showing the inside of the coater transport tank 20 of the second embodiment.

This embodiment is different from the first embodiment in the form of the first pipe 50 or the second pipe 60 introduced into the coater transfer tank 20 or the coater supply tank 30 . In the present embodiment, descriptions of the same parts as in the first embodiment will be omitted.

As described above, one of the main causes of the occurrence of air bubbles in the coater transfer tank 20 is that the electrode slurry introduced into the coater transfer tank 20 through the first pipe 50 falls from above, and the coater transfer tank ( 20) because it falls. In this embodiment, in order to prevent this, the electrode slurry is discharged toward the inner wall surface of the coater transfer tank without dropping the slurry directly from the extension part 51 of the first pipe extending into the coater transfer tank 20 to the bottom of the tank. are doing For example, when the end of the first pipe extension part 51 is bent toward the inner wall surface of the coater transfer tank 20 as shown in FIG. 5 , the electrode slurry is transferred from the opening 51a of the extension part to the inner wall surface of the coater transfer tank 20 . will flow along Therefore, it is possible to prevent the formation of bubbles due to the impact of the electrode slurry directly falling to the lower part of the tank.

The direct drop prevention of electrode slurry in the coater transfer tank 20 may be applied not only to the first pipe extension 51 , but also to the extension part of the return pipe 62 . That is, as shown in FIG. 4, when the return pipe 62 constituting the electrode slurry circulation line extends into the coater transfer tank, the extended portion of the return pipe 62 also faces the inner wall surface of the coater transfer tank. When configured to discharge the electrode slurry, it is possible to effectively suppress the generation of bubbles in the coater transfer tank 20 . That is, by configuring the extension of the return pipe to be bent toward the inner wall of the coater transfer tank in the same way as the extension of the first pipe, the electrode slurry is discharged from the opening 62a of the extension toward the inner wall of the tank. can do.

6 is a perspective view showing the inside of a coater transfer tank 20 of a modified example of the second embodiment.

The modified example of FIG. 6 is different from FIG. 5 in the shape of the extension part 51 of the first pipe extending into the coater transfer tank 20 . The extension 51 of FIG. 6 is extended along the inner peripheral surface of the coater transfer tank 20, and the opening 51a at the end of the extension 51 is opened toward the inner wall of the coater transfer tank. . When the electrode slurry is discharged from the opening 51a toward the inner wall surface of the coater transfer tank 20, the electrode slurry flows down in a circle along the inner circumferential surface of the coater transfer tank by the discharge force. In the example of Figure 5, the electrode slurry is discharged to the inner wall surface of the coater transfer tank 20, but flows down along the inner wall surface in a straight line. On the other hand, in the example of FIG. 6, since the discharge direction of the pipe opening 51a is disposed along the inner circumferential surface of the coater transfer tank, the electrode slurry does not directly flow down the inner wall surface, but flows along the periphery of the tank inner wall surface. , it is possible to more effectively prevent the generation of air bubbles. Furthermore, while FIG. 5 shows that a certain impact is applied to the inner wall surface of the tank by the discharge pressure from the pipe opening 51a, the modified example of FIG. The impact is also reduced compared to the example of FIG. 5 .

The first pipe extension 51 extending into the coater transfer tank 20 of FIG. 6 is formed in one branch along the inner circumferential surface of the tank as shown in FIG. It is also possible to form a conduit pipe. The bifurcated pipes 51 and 51' extend in opposite directions along the inner circumferential surface of the coater transfer tank. 6(b) has an advantage in that the electrode slurry can be discharged into the coater transfer tank 20 more quickly and effectively than in FIG. 6(a).

In addition, as shown in FIG. 6 , the pipe of the extension part 51 may be formed to have a larger diameter toward the openings 51a and 51a' at the ends thereof. In this case, the discharge amount can be increased by the larger openings 51a and 51a' while reducing the discharge pressure toward the inner wall surface. When the discharge pressure is reduced, it is possible to further suppress the generation of bubbles.

The extension parts 51 and 51' branching into one or both branches may be installed horizontally in the coater transfer tank. In this case, the electrode slurry is horizontally sprayed onto the inner wall surface of the coater transfer tank and flows down in a circle along the inner peripheral surface.

Alternatively, the extension parts 51 and 51 ′ may be installed to be inclined downward of the coater transfer tank 20 . In this case, the path through which the electrode slurry flows along the inner circumferential surface of the tank may be somewhat shorter than in the case of horizontal installation, but the electrode slurry may be discharged into the tank more quickly as the pipe is inclined toward the bottom of the tank.

On the other hand, although only the shape of the first pipe part extending to the coater transport tank 20 has been described in FIGS. 5 and 6 , the shape of the return pipe 62 extending to the coater transport tank 20 is also shown in FIG. 5 , as described above. Alternatively, it may be configured as shown in FIG. 6 . In this case, it is important to arrange so that the extension part 51 of the first pipe and the extension part of the return pipe 62 do not overlap each other and not collide with the stirring member 22 rotating in the coater transfer tank 20 . .

In addition, the extension part 66 of the second pipe introduced into the coater supply tank 30 may be configured in the same shape as the extension part 51 of FIG. 5 or FIG. 6 .

The operation process by the above electrode slurry transport system of the present invention will be described below.

First, during the transfer of the electrode slurry from the mixer storage tank 10 to the coater 40, that is, during system operation, the fluid communication between the natural vent part 23 and the external atmosphere is blocked by closing the valve 85, and the A/ Forced exhaust to the C tower by the forced vent portion 24 is performed, and air is forcibly exhausted from the coater transfer tank 20 .

At this time, air flows backward from the coater transfer tank 20 to the first and second pipes 50 and 60 by the check valves 55 and 65 installed in the first pipe 50 or the second pipe 60 . is prevented from becoming

In addition, the electrode slurry introduced into the coater transfer tank 20 does not directly fall to the bottom of the tank by the extension 51 of the first pipe introduced into the coater transfer tank 20 , but on the inner wall surface of the coater transfer tank 20 . It falls in a circle along the or along the inner circumferential surface.

Accordingly, in the electrode slurry transport system 300, the inflow of air (bubbles) is organically prevented.

On the other hand, if a large amount of air bubbles are generated in the coater transfer tank 20 for some reason, the fluid connection of the forced vent part 24 to the A/C tower and the fluid connection to the natural vent part 23 are blocked. In this state, the vacuum pump VP is operated. A large amount of air bubbles in the coater transfer tank 20 can be quickly discharged through the vacuum pump connection part by the high vacuum of the vacuum pump.

After the operation of the vacuum pump (VP) is finished, the fluid communication of the natural vent unit 23 is opened to increase the internal pressure of the coater transfer tank. In this case, the fluid connection of the forced vent to the A/C tower remains closed. When the internal pressure of the coater transfer tank 20 rises to an appropriate level for electrode slurry transfer, the fluid communication to the natural vent part 23 is blocked and the fluid connection of the forced vent part 24 to the A/C tower is opened. .

When there is no longer the introduction of the electrode slurry from the mixer storage tank 10 in the last stage of operation of the system, and the remaining slurry of the first pipe 50 is removed, the pig 1 is put into the first pipe 50 . And move the pig (1) by blowing compressed air. At this time, the vacuum pump VP is operated again to discharge the air introduced by the compressed air from the coater transfer tank 20 .

As described above, the electrode slurry transport system of the present invention actively blocks the inflow of air bubbles into the system, and allows the generated air bubbles to be discharged quickly, thereby preventing the occurrence of defects due to air bubbles very effectively. Thereby, it is possible to perform electrode production without any setback without installation or operation of a defoaming device that causes cost increase and system immobility.

Above, the present invention has been described in more detail with reference to the drawings and examples. However, the configuration described in the drawings or embodiments described in the present specification is only one embodiment of the present invention and does not represent all the technical spirit of the present invention, so at the time of the present application, various equivalents and It should be understood that there may be variations.

1: Pig
2: Pig feed tube
3: Pig discharge pipe
10: mixer storage tank
11: drive motor
12: stirring member
20: coater transfer tank
21: drive motor
22: stirring member
23: natural vent part
24: forced vent unit
30: coater supply tank
31: drive motor
32: stirring member
40: coater
50: first pipe
51,51': first pipe extension part
51a, 51a': extension opening
55: check valve
60: second pipe
61: first partial piping
62: return pipe
62: return pipe opening
63: 3-way valve
64: second partial pipe
65: check valve
66: second pipe extension
70: cotter connection pipe
80: third pipe
81: first branch pipe
82: second branch pipe
85: valve
90: A/C tower connection piping
P1, P2: Pump
VP: vacuum pump
F: filter

Claims (19)

In the electrode slurry transfer system for transferring the electrode slurry from the mixer in which the electrode slurry is mixed to the coater for coating the electrode slurry,
a mixer storage tank to which the electrode slurry is introduced from the mixer;
a coater transfer tank connected to the mixer storage tank by a first pipe;
a coater supply tank connected to the coater transfer tank by a second pipe and supplying the electrode slurry supplied from the coater transfer tank to the coater; including,
The coater transfer tank includes a natural vent unit connected to the external atmosphere and a forced vent unit fluidly connected to the A/C tower, and while the air in the coater transfer tank is forcibly exhausted through the forced vent unit, the natural vent unit and Electrode slurry conveying system in which fluid communication with the outside atmosphere is blocked.
According to claim 1,
An electrode slurry transport system in which air in the coater transport tank is forcibly exhausted even during transport of the electrode slurry by maintaining the inside of the coater transport tank in a weak vacuum state by the forced exhaust by the forced vent unit.
3. The method of claim 2,
The weak vacuum state is an electrode slurry transport system in which the differential pressure between the coater transport tank and the external atmosphere is less than -20pa.
3. The method of claim 2,
The weak vacuum state is an electrode slurry transport system that is controlled by adjusting an opening rate of a valve installed in a pipe connecting the forced vent unit and the A/C tower.
According to claim 1,
An electrode slurry transport system in which a check valve for preventing backflow of air is installed in at least one of an adjacent part of the coater transport tank of the first pipe and an adjacent part of the coater supply tank of the second pipe.
According to claim 1,
The coater transfer tank further includes a vacuum pump connection part connected to a vacuum pump, and the vacuum pump is operated in an emergency when a large amount of bubbles in the tank are generated to stop the system operation.
7. The method of claim 6,
The natural vent part and the vacuum pump connection part are formed in the same opening on the coater transfer tank, and the pipe connected to the opening is a first branch pipe connected to the external atmosphere and a second branch pipe connected to the vacuum pump. Branched electrode slurry conveying system.
8. The method of claim 7,
An electrode slurry transfer system in which the natural vent unit and the external atmosphere are in fluid communication to increase the internal pressure of the coater transfer tank for transferring the electrode slurry after the operation of the vacuum pump is terminated and before the system is restarted.
7. The method of claim 6,
When the introduction of the electrode slurry from the mixer storage tank to the first pipe is stopped and pigs are put into the first pipe to remove the residual slurry in the first pipe, the vacuum pump is operated.
According to claim 1,
A return pipe returning to the coater transfer tank is branched from the second pipe, and a 3-way valve is installed at a branch portion of the second pipe and the return pipe.
According to claim 1,
The first pipe extends into the coater transfer tank,
The end of the first pipe extending into the coater transfer tank is configured to discharge the electrode slurry toward the inner wall surface of the coater transfer tank.
12. The method of claim 11,
The end of the first pipe is bent toward the inner wall surface of the coater transfer tank electrode slurry transfer system.
12. The method of claim 11,
An extension portion of the first pipe into the coater transfer tank extends along an inner circumferential surface of the coater transfer tank, and an opening at an end of the extension portion is opened toward an inner wall surface of the coater transfer tank.
14. The method of claim 13,
An electrode slurry transfer system in which the extension portion of the first pipe into the coater transfer tank is installed horizontally in the coater transfer tank.
14. The method of claim 13,
An electrode slurry transfer system in which the extension of the first pipe into the coater transfer tank is inclined downwardly of the coater transfer tank.
14. The method of claim 13,
The electrode slurry transport system formed so that the extension of the first pipe to the inside of the coater transfer tank increases in diameter toward the opening of the end of the extension.
14. The method of claim 13,
The extension portion of the first pipe into the coater transport tank forms a pipe branching from the first pipe, and the branched pipe extends along the inner circumferential surface of the coater transport tank in opposite directions. .
11. The method of claim 10,
The return pipe returning to the coater transfer tank extends into the coater transfer tank, and the end of the return pipe extending into the coater transfer tank is configured to discharge the electrode slurry toward the inner wall surface of the coater transfer tank. .
19. The method of claim 18,
The end of the return pipe is bent toward the inner wall surface of the coater transfer tank electrode slurry transfer system.

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