JP5392332B2 - Drying equipment - Google Patents

Description

The present invention relates to a drying apparatus for drying a material to be dried using atmospheric superheated steam, and in particular, in a non-aqueous electrolyte secondary battery such as a lithium ion battery, drying after applying an active material solution to a current collector It is related with the drying apparatus suitable for.

In a non-aqueous electrolyte secondary battery such as a lithium ion battery, the electrode is formed by applying an active material (eg, lithium composite oxide, carbon material) solution to a current collector (eg, aluminum foil, copper foil) made of a metal foil. After the solvent (solvent) is dried and evaporated, the active material is pressed to a certain thickness.
As a drying apparatus used after applying an active material solution to a current collector, a configuration in which hot air is blown from a hot air nozzle to dry is generally used (see, for example, Patent Document 1).
In addition, as a drying device specializing in a material to be dried on a coated film or a wet film (film to be dried), the drying chamber was heated by a heating unit and a heating unit for maintaining the internal temperature and preheating the film to be dried. The superheated steam jetting part for jetting normal pressure superheated steam heated to 100 to 300 ° C. with respect to the film to be dried, and the volatility in which the normal pressure superheated steam is jetted from the superheated steam jet part onto the film to be dried. Some have a plurality of sets of exhaust suction parts for recovering drainage steam containing organic solvent components and the like (see, for example, Patent Document 2).
Furthermore, as an electromagnetic induction heating device suitable for generation of atmospheric superheated steam, a heating element immersed in a non-magnetic material pipe through which a fluid passes is divided into a base material that forms a multilayer structure and a multilayer structure. There is a highly responsive electromagnetic induction heating device by direct heating that is heated by electromagnetic induction, which is a multilayer structure having a large number of formed regular fluid passages (see, for example, Patent Documents 3 and 4).

JP 2008-103098 A JP 2007-276283 A Japanese Patent No. 2889607 Japanese Patent No. 3628705

In the configuration in which hot air (about 130 ° C. is the upper limit of temperature) is blown from a hot air nozzle as in Patent Document 1 as a drying device for an electrode of a non-aqueous electrolyte secondary battery, drying is performed from the surface by hot air, The drying time (drying distance) becomes longer due to the need for a preheating zone for gradually increasing the temperature of the coating film of the active material applied to the current collector to the boiling point of the solvent (eg, 204 ° C.). There is a problem that the occupation area of the drying device becomes large.
Moreover, when the drying apparatus of the to-be-dried film like patent document 2 is applied to the drying apparatus of the electrode of a non-aqueous electrolyte secondary battery, the normal pressure overheating heated at 100-300 degreeC with high heat conductivity is carried out. Since water vapor is used, the drying efficiency is higher than that using hot air, and it is considered that the drying time (drying distance) can be made relatively short.
However, the drying apparatus of Patent Document 2 is specialized for drying of a film, and in combination with the need for a heating unit for maintaining the internal temperature and preheating the film to be dried, atmospheric superheated steam is generated. There is room for improvement in order to use and dry the electrodes of the non-aqueous electrolyte secondary battery more efficiently.

Therefore, in view of the above-mentioned situation, the present invention intends to solve a drying apparatus for drying a material to be dried more efficiently using atmospheric superheated steam, particularly for drying an electrode of a non-aqueous electrolyte secondary battery. It is in providing a suitable drying apparatus .

  The inventor of the present application uses a normal-pressure superheated steam in order to efficiently dry the non-aqueous electrolyte secondary battery such as a lithium ion battery after applying the active material solution to the current collector. The present invention has been completed by advancing the embodiment by examination, experimentation, trial manufacture, etc. for utilizing characteristics such as sex.

In the following, first, superheated steam will be described.
As shown in the temperature-pressure phase diagram of water in FIG. 3, water can be classified into a solid phase, a liquid phase, and a gas phase according to its temperature and pressure. That is, the region on the left side of the sublimation curve TB on the left side of the melting curve TA is the solid phase, the region on the left side of the evaporation curve TC on the right side of the melting curve TA is the liquid phase, and the region on the right side of the sublimation curve TB and the evaporation curve TC is the gas phase. become.
Here, in the gas phase, water exists as water vapor, and water having physical properties generally called water vapor exists at a point P of 1 atm and 100 ° C., and the water vapor located in the region on the right side of the evaporation curve TC, ie, the pressure. Steam that is heated to a temperature equal to or higher than the corresponding saturation temperature (steam having a temperature higher than the boiling point) is called superheated steam.

The water vapor condenses and turns into a white dull vapor in the temperature range below the dew point, and the water vapor that looks white like this is interpreted as a mass of condensed water floating in the air, with a diameter of 30 μm or more. It becomes a state of white haze that is visible in the eyes.
However, it is understood that even when the superheated steam in a high temperature state that greatly exceeds the point P on the right side (normal pressure superheated steam reaching a region of about 200 ° C. or more) is returned to the dew point or less, it does not easily become white moisture. It is presumed that the water vapor once raised to a high temperature region is difficult to condense or obtain some energy, so that it is difficult to have a diameter of 30 μm or more.
In fact, even if superheated steam is supplied in a supersaturated space, the space is not white and dull, and a very clear space can be maintained.
Moreover, it is estimated that the water vapor that has reached this high temperature region exists in a single molecular state, and therefore, it is considered that the water vapor easily enters an air space such as a fine gap.

Next, the removal of the solvent of the active material solution applied to the current collector of the electrode of the nonaqueous electrolyte secondary battery will be described.
Since the solvent cannot be removed unless it evaporates, it is necessary to bring the solvent to a temperature higher than the boiling point.
However, it has been found that if the active material solution applied to the current collector is rapidly dried at a temperature equal to or higher than the boiling point of the solvent, the solvent bumps and the dried surface is burnt.
Therefore, in the conventional drying apparatus, the preheating zone for gradually raising the temperature of the coating film of the active material applied to the current collector to the boiling point of the solvent as described above is necessary.

In view of the above, the inventor of the present application is heated to about 200 ° C. or more in order to make the preheating zone unnecessary while spraying atmospheric superheated steam after applying the active material solution to the current collector and drying. The atmospheric pressure superheated steam that has become transparent is less than the boiling point of the solvent that is removed by vaporization, and the temperature is lowered to a high temperature within a range where the binding force between the current collector and the active material does not decrease As described above, heating is performed while utilizing the heat storage effect, and high osmotic power that is maintained even if the temperature of the atmospheric superheated steam that reaches the region of about 200 ° C. or higher is lowered as described above. Taking advantage of the characteristics, the idea was to dry efficiently while maintaining a good dry surface where the dry surface does not burn.
In addition, in order to prevent condensation and promote drying, a mixed gas in which atmospheric pressure dry air is mixed with atmospheric pressure steam can be supplied to the electromagnetic induction heating device while changing the mixing ratio, and drying is performed. The idea was to control the humidity in the drying chamber by manipulating the amount of atmospheric heated dry air supplied to the chamber (ratio of atmospheric heated dry air to atmospheric superheated steam).

That is, a drying device according to the present invention is a drying device for drying a material to be dried in a drying chamber for solving the above-described problem, and an electromagnetic induction heating device to which water or water vapor is supplied through a pipeline, A controller for controlling the electromagnetic induction heating device so as to generate normal-pressure superheated steam that is transparent at about 200 ° C. or more by heating water or water vapor; and an overheat connected to the drying chamber and the electromagnetic induction heating device The atmospheric pressure superheated steam that became transparent at about 200 ° C. or more was passed through the superheated steam supply pipe, and the temperature was lowered to a predetermined temperature suitable for the material to be dried. The state is supplied to the drying chamber, and the material to be dried is the current collector and the active material after the active material solution is applied to the current collector of the non-aqueous electrolyte secondary battery, and the material to be dried Suitable predetermined Degree is, the the temperature of the solvent below the boiling point of the active substance solution, and, wherein the temperature der Rukoto the binding force is set high within a range that does not decrease in the current collector and the active material.

According to such a configuration, the control device controls the electromagnetic induction heating device to heat water or water vapor, to generate normal pressure superheated water vapor that is transparent at about 200 ° C. or more, By passing through the superheated steam supply pipe, it is supplied to the drying chamber in a state lowered to a predetermined temperature suitable for the material to be dried, so that it can be dried at a predetermined temperature suitable for the material to be dried. In addition, since it is possible to make use of characteristics such as high osmotic force that can be maintained even if the temperature of the atmospheric superheated steam reaching a region of about 200 ° C. or higher is lowered, the material to be dried can be efficiently dried. .
In addition, since the atmospheric pressure superheated steam is filled in the drying chamber, the inside of the drying chamber can be brought into an oxygen-free state, and thus the prevention of oxidation of the material to be dried can be promoted.
Further, the material to be dried is the current collector and the active material after the active material solution is applied to the current collector of the non-aqueous electrolyte secondary battery, and the predetermined temperature suitable for the material to be dried is A non-aqueous electrolyte solution such as a lithium ion battery having a temperature lower than the boiling point of the solvent of the active material solution and a temperature set high in a range in which the binding force between the current collector and the active material does not decrease In the drying of the current collector and the active material after applying the active material solution to the current collector of the secondary battery, the solvent is removed by vaporizing the atmospheric superheated steam that is heated to about 200 ° C. or more and becomes transparent In the drying chamber in a state where the temperature is lowered to a temperature set high (for example, 180 ° C.) within a range in which the binding force between the current collector and the active material is not decreased. As it is supplied, it reaches an area of about 200 ° C or higher. Utilizing characteristics such as high osmotic force that can be maintained even if the temperature of atmospheric superheated steam is lowered, heat is generated from the current collector (core material) instead of drying from the surface, and the solvent is removed from the inside while utilizing the heat storage effect. Since it is possible to dry and evaporate, it is possible to efficiently dry while maintaining a good dry surface where the dry surface is not burnt, so that a preheating zone can be eliminated.

Here, a heating / drying air supply device that supplies atmospheric pressure heating / drying air to the drying chamber through a pipe line, and a humidity sensor that detects humidity in the drying chamber, the heating / drying air supply device provides the drying chamber. It is preferable to provide a control device for controlling the humidity in the drying chamber detected by the humidity sensor to be equal to or lower than a predetermined humidity or within a predetermined humidity range by adjusting the amount of the atmospheric pressure heated dry air supplied to the air.
According to such a configuration, normal pressure heated dry air is supplied into the drying chamber, the supply amount thereof is adjusted, and the humidity in the drying chamber is equal to or lower than a predetermined humidity (for example, 20%) or within a predetermined humidity range (for example, 10% to 20%), the humidity in the drying chamber is significantly lower than the humidity in the drying chamber in a normal drying apparatus (for example, 70 to 80%). Since the state can be maintained, the material to be dried can be dried more efficiently.

  Furthermore, in order to solve the above problems, the drying apparatus according to the present invention provides the current collector after applying an active material solution to a current collector of a non-aqueous electrolyte secondary battery, which is a material to be dried in a drying chamber. A drying apparatus for drying a body and an active material, a steam generating apparatus for generating atmospheric pressure steam, a drying air generating apparatus for generating atmospheric dry air, and the atmospheric steam connected to the steam generating apparatus The normal-pressure steam and the normal-pressure dry air are supplied through a mixed gas supply line connected to the supplied steam supply line and the dry-air supply line connected to the dry-air generator and supplied with the normal-pressure dry air. An electromagnetic induction heating device to which a mixed gas is supplied, a control device for controlling the electromagnetic induction heating device so as to generate atmospheric superheated steam that is transparent at about 200 ° C. or more by heating the mixed gas, Drying chamber A superheated steam and heated dry air supply line connected to the electromagnetic induction heating device, a humidity sensor for detecting the humidity in the drying chamber, and supply to the drying chamber through the superheated steam and heated dry air supply line A control device for controlling the humidity in the drying chamber detected by the humidity sensor to be equal to or lower than a predetermined humidity or within a predetermined humidity range by adjusting the amount of dry air heated under normal pressure, and transparent at 200 ° C. or higher The normal pressure superheated water vapor is passed through the superheated water vapor and heated dry air supply line so that the temperature is less than the boiling point of the solvent of the active material solution and the collector and the active material are bonded. The drying chamber is supplied in a state in which the temperature is lowered to a temperature set high within a range in which the adhesion force does not decrease.

According to such a configuration, in the drying of the current collector and the active material of the active material solution after the active material solution is applied to the current collector of a non-aqueous electrolyte secondary battery such as a lithium ion battery, A mixed gas of normal pressure steam and normal pressure dry air is supplied to the induction heating device, and the control device controls the electromagnetic induction heating device to generate normal pressure superheated steam that becomes transparent at about 200 ° C or higher by the electromagnetic induction heating device. The boiling point of the solvent removed by vaporizing the mixed gas of the normal pressure superheated steam and the normal pressure heated dry air through the superheated steam and heated dry air supply line connected to the drying chamber and the electromagnetic induction heating device (for example, 204 ° C.) and is supplied to the drying chamber in a state in which the temperature is lowered to a high temperature (for example, 180 ° C.) within a range in which the binding force between the current collector and the active material does not decrease. Therefore, taking advantage of characteristics such as high penetrating power that can be maintained even if the temperature of atmospheric superheated steam that reaches a temperature of about 200 ° C or higher is lowered, heat is generated from the current collector (core material) rather than drying from the surface. Since the solvent can be dried and evaporated from the inside while utilizing the heat storage effect, the drying surface can be efficiently dried while keeping the dry surface in a good condition, thus eliminating the need for a preheating zone it can.
In addition, the amount of atmospheric pressure heated dry air supplied to the drying chamber through the superheated steam and heated drying air supply line is adjusted by the controller, and the humidity in the drying chamber detected by the humidity sensor that detects the humidity in the drying chamber is adjusted. The humidity is controlled by the control device so that the humidity is equal to or lower than a predetermined humidity (for example, 20%) or within a predetermined humidity range (for example, 10% to 20%). Since the humidity in the drying chamber can be kept significantly lower than the humidity (for example, 70 to 80%), the current collector and the active material can be further efficiently dried.
Furthermore, since the atmospheric pressure superheated steam is filled in the drying chamber, the inside of the drying chamber can be brought into an oxygen-free state, so that the current collector and the active material can be prevented from being oxidized.
In addition, since a mixed gas of normal pressure steam and normal pressure dry air is supplied to the electromagnetic induction heating device, the electromagnetic induction heating device generates normal pressure superheated steam reaching a region of about 200 ° C. or higher. Since it is configured to perform both heating of pressurized water vapor and heating of atmospheric pressure drying air used for humidity control in the drying chamber, there is no need to separately provide a heating / drying air supply device for supplying atmospheric pressure heating / drying air to the drying chamber. .

As described above, according to the drying apparatus according to the present invention, the normal pressure superheated steam that is transparent at about 200 ° C. or more is generated by the electromagnetic induction heating device, and this normal pressure superheated steam is suitable for the material to be dried. Since it is supplied to the drying chamber in a state lowered to a predetermined temperature, it can be dried at a predetermined temperature suitable for the material to be dried, and at that time, the atmospheric superheated steam that has reached an area of about 200 ° C. or higher Since the characteristics such as high osmotic force maintained even if the temperature is lowered can be utilized, the material to be dried can be efficiently dried, and the supply amount of atmospheric pressure heated dry air supplied into the drying chamber is Since the humidity in the drying chamber is adjusted and controlled to be equal to or lower than the predetermined humidity, the humidity in the drying chamber can be kept low, so that the material to be dried can be more efficiently dried. it can A marked effect say.

It is a block diagram which shows the structural example of the drying apparatus which concerns on embodiment of this invention. It is a schematic longitudinal cross-sectional view which shows the structural example in a drying chamber. It is a temperature-pressure phase diagram of water.

The drying apparatus according to the embodiment of the present invention shown in the block diagram of FIG. 1 is used, for example, for manufacturing an electrode of a lithium ion battery that is a non-aqueous electrolyte secondary battery, and is generated by the electromagnetic induction heating apparatus 1. By supplying the superheated steam under pressure to the drying chamber 2 through the superheated steam supply line (superheated steam and heated dry air supply line) L4, a solvent (for example, N) of the active material (for example, lithium composite oxide, carbon material) solution. -Methyl-2-pyrrolidone, Sankyo Chemical Co., Ltd. trade name: NMP) is dried and evaporated. That is, the material to be dried of the drying apparatus according to the present embodiment is the current collector A and the active material after the active material solution is applied to the current collector A of the lithium ion battery.
Here, a transport system (refer to arrow F in the figure for the transport direction) of a current collector A (for example, an aluminum foil or a copper foil) made of a strip-shaped metal foil constituting the electrode is disposed upstream of the drying chamber 2. The current collector A wound around a feeding roller (not shown) positioned is wound around a winding roller (not shown) located downstream of the drying chamber 2 while being fed out. A current collector A having an active material solution coated on its surface by a coating device (not shown) on the upstream side is transported through the drying chamber 2 to the downstream side at a predetermined transport speed. Further, the transport speed of the transport system is detected by a transport speed sensor 10, and this detected value is sent to the control device 3.

The electromagnetic induction heating device 1 superheats a fluid by direct heating without using a heat exchanger, and includes a device main body 1A and a high-frequency current generator 1B. Here, the apparatus main body 1A includes an insulating column (a pipe made of a nonmagnetic material), an energized exciting coil wound around the insulating column, and an insulating column, as in the electromagnetic induction heating devices of Patent Documents 3 and 4. It has a heating element that is immersed in a fluid and generates heat by generating eddy currents due to electromagnetic induction by an exciting coil. The heating element is a regular structure formed by a base material that forms a multilayer structure and a multilayer structure. A multilayer structure having a large number of fluid passages is provided. The high-frequency current generator 1B includes a rectifier circuit of an AC power supply, an inverter, and the like, and is used to flow a high-frequency current through the excitation coil of the apparatus main body 1A.
According to such an electromagnetic induction heating device by direct heating, the specific surface area of the heat transfer area per unit volume of the fluid can be made extremely large, the heat transfer efficiency from the heating element to the fluid becomes very high, and the response Therefore, the present invention is suitable as an electromagnetic induction heating device that controls the temperature of a fluid as in the present invention.
Further, a temperature sensor 1T is installed on the outflow side of the apparatus main body 1A, and the detected value of the temperature sensor 1T is sent to the control device 3, and the control device 3 supplies a high-frequency current to the exciting coil from the high-frequency current generator 1B. Is controlled.

As shown in FIG. 1, normal-pressure steam is supplied to a steam supply line L1 from a steam generator 4 that is a boiler for pure water, for example, and is dried from a dry air generator 5 that is, for example, an air tank, a compressor, and a dryer. Since normal pressure dry air is supplied to the air supply line L2, the normal pressure is supplied to the apparatus main body 1A of the electromagnetic induction heating device 1 via the mixed gas supply line L3 where the lines L1 and L2 merge. A mixed gas of water vapor and atmospheric dry air is supplied.
Here, the normal-pressure steam supplied from the steam generator 4 to the steam supply pipe L1 can be adjusted in flow rate by the steam flow control valve 6A installed in the pipe L1, and the flow rate is determined by the steam flow sensor 6B. The detected value of the steam flow sensor 6B is sent to the control device 3, and the steam flow control valve 6A is controlled by the control device 3.
The normal pressure dry air supplied from the dry air generator 5 to the dry air supply pipe L2 can be adjusted in flow rate by an air flow rate control valve 7A installed in the pipe L2, and the flow rate is the air flow rate. Detected by the sensor 7B, the detected value of the air flow sensor 7B is sent to the control device 3, and the control device 3 controls the air flow control valve 7A.
Furthermore, the flow rate of the mixed gas of the normal pressure steam and the normal pressure dry air supplied to the mixed gas supply line L3 can be adjusted by the mixed gas flow rate control valve 8A installed in the line L3. Is detected by the mixed gas flow rate sensor 8B, and the detected value of the mixed gas flow rate sensor 8B is sent to the control device 3, which controls the mixed gas flow rate control valve 8A.

The mixed gas of the normal pressure steam and the normal pressure dry air supplied from the mixed gas supply line L3 to the apparatus main body 1A of the electromagnetic induction heating apparatus 1 generates normal pressure superheated steam that becomes transparent at about 200 ° C. or higher. Thus, the electromagnetic induction heating device 1 is heated.
The temperature of the normal-pressure superheated steam that became transparent at about 200 ° C. or more generated in this way is the superheated steam and heated and dried air supply pipe L4 (pipe section 2A, 2A or 2B, 2B shown in FIG. 2). L41 or L42 is also included), and the temperature is lower than the boiling point of the solvent of the active material solution that is a predetermined temperature suitable for the material to be dried (204 ° C. when the solvent is N-methyl-2-pyrrolidone), In addition, the pressure is reduced to a high temperature (for example, 180 ° C.) within a range where the binding force between the current collector A and the active material does not decrease, and the atmospheric superheated steam in this state is introduced into the drying chamber 2. Is done.

In addition, the tube from the electromagnetic induction heating device 1 to the jetting parts 2A, 2A or 2B, 2B for reducing the temperature of the normal pressure superheated steam that becomes transparent at about 200 ° C. or more to a predetermined temperature suitable for the material to be dried Since the length of the path L4 varies depending on the type and thickness of the material to be dried, it can be determined by experiment or trial production. Thus, the temperature of the atmospheric superheated steam that becomes transparent at about 200 ° C. or higher is targeted. The fine adjustment for adjusting the temperature (a predetermined temperature suitable for the material to be dried) can be performed, for example, by adjusting the flow rate by operating the steam flow rate control valve 6A or the mixed gas flow rate control valve 8A.
Further, since the mixed gas of the normal pressure steam and the normal pressure dry air is supplied to the apparatus main body 1A of the electromagnetic induction heating apparatus 1, the normal pressure superheated steam is used together with the normal pressure superheated steam whose temperature is lowered to the predetermined temperature. The normal pressure dry air at the same temperature is also introduced into the drying chamber 2 via the line L4.

For example, as shown in the schematic longitudinal cross-sectional view of FIG. 2, the current collector A applied on both sides of the active material solution transported in the drying chamber 2 is installed so as to be separated on both sides. As described above, the superheated steam and heated dry air supply pipes are formed from the ejection portions 2A, 2A and 2B, 2B, which are boxes formed with a large number of through holes having a diameter of about 1 to 2 mm on the surface facing the current collector A. The mixed gas G in a state where the temperature is lowered to the predetermined temperature is ejected via L4.
Here, the temperature and humidity in the drying chamber 2 are detected by the temperature sensor 2T and the humidity sensor 2H shown in FIG. 1, and the detected value of the temperature sensor 2T and the detected value of the humidity sensor 2H are sent to the control device 3 for control. The device 3 controls the temperature and humidity in the drying chamber 2 as will be described later.
For the current collector A on which the active material solution is applied on one side, the ejection parts 2A, 2A and the ejection part so that the mixed gas G is ejected from the side facing the one side on which the active material solution is applied. Only one of 2B and 2B is assumed.
Further, the actuator that opens and closes the damper 9 is controlled by the control device 3, and the gas vaporized by the solvent of the active material solution is exhausted from the damper 9 via the exhaust line L5.

Next, the drying method according to the embodiment of the present invention will be described.
(Preheating process in drying chamber)
In the drying apparatus having the configuration shown in FIG. 1, the steam flow rate control valve 6A is closed, the air flow rate control valve 7A is opened, and the normal pressure dry air is supplied from the dry air generator 5 to the line L2, and the line L3 is passed through. Thus, only the normal pressure dry air is supplied to the apparatus main body 1A of the electromagnetic induction heating apparatus 1.
The normal pressure dry air is heated to a predetermined temperature (for example, about 150 ° C. to 160 ° C.) by the electromagnetic induction heating device 1, and the normal pressure heated dry air thus heated is supplied into the drying chamber 2 from the line L 4. By doing so, the temperature in the drying chamber 2 detected by the temperature sensor 2T is increased to a predetermined temperature of 100 ° C. or higher (for example, 120 ° C.), and the temperature of the inner wall of the drying chamber 2 is set to 100 ° C. or higher.
By this step, it is possible to suppress the occurrence of condensation due to supplying superheated steam into the cooled drying chamber 2.

(Drying process of material to be dried)
Next, in the drying apparatus having the configuration shown in FIG. 1, the steam flow control valve 6A is opened to supply atmospheric steam from the steam generator 4 to the pipe L1, and the air flow control valve 7A is opened to dry the air generator. The normal pressure dry air is supplied from 5 to the line L2, and the mixed gas of normal pressure water vapor and normal pressure dry air is supplied to the apparatus main body 1A of the electromagnetic induction heating apparatus 1 via the line L3.
The mixed gas is heated by the electromagnetic induction heating device 1 to generate normal-pressure superheated steam that is heated to about 200 ° C. or higher at normal pressure and becomes transparent, and passes through the pipe L4 as described above, and the active material solution Normal pressure superheated steam and heating in a state where the temperature is lower than the boiling point of the solvent and the temperature is lowered to a high temperature (for example, 180 ° C.) within a range where the binding force between the current collector A and the active material does not decrease A mixed gas G with dry air (see FIG. 2) is supplied to the drying chamber 2.
And while conveying the collector A coated with the active material solution on the downstream side at a predetermined conveyance speed by the conveyance system, while heating using the heat storage effect by the mixed gas G, about as described above Utilizing characteristics such as high osmotic power that can be maintained even if the temperature of atmospheric superheated steam reaching 200 ° C or higher is lowered, heat is collected from current collector A (core material) instead of drying from the surface, thereby storing heat. Since the solvent of the active material solution can be dried and evaporated from the inside while utilizing the effect, the dry surface can be efficiently dried while keeping the dry surface in a good condition, thus eliminating the need for a preheating zone. be able to.

Here, since the detected value of the temperature sensor 2T is sent to the control device 3, the control device 3 refers to the transport speed detected by the transport speed sensor 10 and unit time for drying and evaporating the solvent of the active material solution. 2, the flow rate of the mixed gas G shown in FIG. 2 to be supplied into the drying chamber 2 is controlled by adjusting the mixed gas flow rate control valve 8A, for example, and the detected value of the temperature sensor 2T is taken into consideration. The temperature can be controlled so as not to decrease too much.
Further, when the material to be dried (the current collector A and the active material) is dried in this way, the detection value of the humidity sensor 2H is sent to the control device 3, so that the control device 3 controls the air flow rate control valve 7A. By operating and adjusting the supply amount of the normal pressure dry air, the amount of the normal pressure heated dry air supplied to the drying chamber 2 can be adjusted. 20% or less) or within a predetermined humidity range (for example, 10% to 20%), the humidity in the drying chamber 2 is more than the humidity (for example, 70 to 80%) in the drying chamber in a normal drying apparatus. Therefore, the current collector A and the active material can be dried more efficiently.
Furthermore, since the atmospheric pressure superheated steam is filled in the drying chamber 2, the inside of the drying chamber 2 can be brought into an oxygen-free state, so that the current collector A and the active material can be prevented from being oxidized.

(Operation stop process)
When the operation of the drying apparatus having the configuration shown in FIG. 1 is stopped, in order to prevent condensation in the drying chamber 2, the steam flow rate control valve 6A is closed and the air flow rate control valve 7A is opened so that the dry air generator 5 always Pressure dry air is supplied to the pipe L2, only normal pressure dry air is supplied from the pipe L3 to the main body 1A of the electromagnetic induction heating apparatus 1, and only the heated dry air heated by the electromagnetic induction heating apparatus 1 is supplied to the pipe L2. L4 is supplied to the drying chamber 2 and the operation is stopped by controlling the electromagnetic induction heating device 1 by the control device 3 so as to gradually lower the temperature of the heated and dried air.

In the above description, a configuration in which a mixed gas of atmospheric pressure steam and atmospheric pressure dry air is supplied to the electromagnetic induction heating device 1 and heated is shown. However, heating of atmospheric pressure steam and heating of atmospheric pressure dry air are different. For example, the structure of the heated dry air supply apparatus separated from the supply and heating route of atmospheric steam, that is, the atmospheric dry air is supplied to the electromagnetic induction heating apparatus 1 and a separate heating apparatus. The atmospheric pressure heated dry air heated in this manner may be supplied to the drying chamber.
However, the mixed gas of atmospheric pressure steam and atmospheric pressure dry air was supplied to the electromagnetic induction heating apparatus 1 as in the drying apparatus having the configuration shown in FIG. 1, and the electromagnetic induction heating apparatus 1 reached an area of about 200 ° C. or higher. According to the configuration that performs both the heating of the normal pressure steam for generating the normal pressure superheated steam and the heating of the normal pressure dry air used for controlling the humidity in the drying chamber 2, the normal pressure heated dry air is supplied to the drying chamber 2. This is a more preferable embodiment because there is no need to separately provide a heated and dry air supply device.

A Current collector F Transport direction G Mixed gas L1 Water vapor supply line L2 Dry air supply line L3 Mixed gas supply lines L4, L41, L42 Superheated steam and heated dry air supply line L5 Exhaust line 1 Electromagnetic induction heating device DESCRIPTION OF SYMBOLS 1A Apparatus main body 1B High frequency current generator 1T Temperature sensor 2 Drying chamber 2A, 2B Spout part 2T Temperature sensor 2H Humidity sensor 3 Controller 4 Steam generator 5 Dry air generator 6A Steam flow control valve 6B Steam flow sensor 7A Air flow control Valve 7B Air flow rate sensor 8A Mixed gas flow rate control valve 8B Mixed gas flow rate sensor 9 Damper 10 Transport speed sensor

Claims (3)

A drying device for drying a material to be dried in a drying chamber,
An electromagnetic induction heating device to which water or steam is supplied through a pipeline;
A control device for controlling the electromagnetic induction heating device so as to generate atmospheric superheated steam that is transparent at about 200 ° C. or more by heating the water or steam;
A superheated steam supply line connected to the drying chamber and an electromagnetic induction heating device;
The normal pressure superheated steam that has become transparent at about 200 ° C. or higher is supplied to the drying chamber in a state where the temperature is lowered to a predetermined temperature suitable for the material to be dried by passing through the superheated steam supply pipe. ,
The material to be dried is the current collector and the active material after the active material solution is applied to the current collector of the non-aqueous electrolyte secondary battery, and a predetermined temperature suitable for the material to be dried is the active material. a temperature below the boiling point of the solvent of the solution, and drying and wherein the temperature der Rukoto the bonding strength between the active material and the current collector is set high within a range that does not decrease. A heated and dried air supply device for supplying atmospheric pressure heated and dried air to the drying chamber through a conduit;
A humidity sensor for detecting the humidity in the drying chamber;
The humidity in the drying chamber detected by the humidity sensor is controlled to be equal to or lower than a predetermined humidity or within a predetermined humidity range by adjusting the amount of the atmospheric pressure heated dry air supplied to the drying chamber by the heated dry air supply device. 2. The drying apparatus according to claim 1, further comprising a control device that performs the control. A drying apparatus for drying the current collector and the active material after applying an active material solution to a current collector of a non-aqueous electrolyte secondary battery, which is a material to be dried in a drying chamber,
A steam generator for generating atmospheric steam,
A dry air generator for generating atmospheric dry air;
A mixed gas supply in which a steam supply line connected to the steam generator and supplied with the normal pressure steam and a dry air supply line connected to the dry air generator and supplied with the normal pressure dry air join together An electromagnetic induction heating device to which a mixed gas of the atmospheric steam and the atmospheric dry air is supplied through a pipe;
A control device for controlling the electromagnetic induction heating device so as to generate atmospheric superheated steam that is transparent at about 200 ° C. or more by heating the mixed gas;
Superheated steam and heated dry air supply lines connected to the drying chamber and electromagnetic induction heating device;
A humidity sensor for detecting humidity in the drying chamber;
The humidity in the drying chamber detected by the humidity sensor is controlled to be equal to or lower than a predetermined humidity or in a predetermined humidity range by adjusting the amount of atmospheric pressure heated dry air supplied to the drying chamber through the superheated steam and heated dry air supply line. And a control device for controlling inside,
The normal pressure superheated steam that becomes transparent at 200 ° C. or higher is passed through the superheated steam and heated dry air supply pipe, so that the temperature is lower than the boiling point of the solvent of the active material solution, and the current collector A drying apparatus, wherein the drying chamber is supplied in a state where the temperature is lowered to a temperature set high in a range in which the binding force between the active material and the active material does not decrease.

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