WO2013039005A1

WO2013039005A1 - Drying device and drying method

Info

Publication number: WO2013039005A1
Application number: PCT/JP2012/072929
Authority: WO
Inventors: 善之塩路
Original assignee: 第一実業株式会社
Priority date: 2011-09-15
Filing date: 2012-09-07
Publication date: 2013-03-21
Also published as: CN104040275B; CN104040275A; JP5392332B2; JP2013064516A

Abstract

The purpose of the present invention is to provide a drying device that uses atmospheric superheated steam to more efficiently dry a material to be dried. The drying device is provided with the following: an electromagnetic induction heater (1) to which a gas mixture of steam and dry air is provided through a conduit (L3) where a conduit (L1) to which atmospheric steam is supplied and a conduit (L2) to which atmospheric dry air is supplied merge; a control device (3) for controlling the electromagnetic induction heater (1) so as to heat the gas mixture and generate atmospheric superheated steam that becomes transparent at approximately 200°C or above; a conduit (L4) for connecting the electromagnetic induction heater (1) and a drying chamber (2); and the control device (3) for controlling the humidity to be at or below a prescribed humidity by adjusting the amount of atmospheric heated dry air supplied to the drying chamber (2). The temperature of the atmospheric superheated steam is lowered to a temperature that is both less than the boiling point of the solvent and high enough to be in a range where there is no reduction in the binding strength between a collector and an active material, the steam is supplied to the drying chamber (2) through the conduit (L4), and the humidity inside the drying chamber (2) is controlled.

Description

Drying apparatus and drying method

The present invention relates to a drying apparatus and a drying method 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, an active material solution is applied to a current collector. The present invention relates to a drying apparatus and a drying method suitable for subsequent drying.

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. Superheated steam jetting part that jets normal pressure superheated steam heated to 100-300 ° C to the film to be dried, and volatile volatility whose temperature is lowered by jetting normal pressure superheated steam from the superheated steam jet part to 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.
Further, when a drying apparatus for a film to be dried as in Patent Document 2 is applied to an electrode drying apparatus for a non-aqueous electrolyte secondary battery, normal pressure overheating heated to 100 to 300 ° C. with high thermal conductivity is performed. 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 situation, the present invention intends to solve a drying apparatus and a drying method for drying a material to be dried more efficiently using atmospheric superheated steam, particularly an electrode of a non-aqueous electrolyte secondary battery. It is in the point which provides the drying apparatus and drying method suitable for drying of this.

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.

Water vapor condenses in the temperature range below its dew point and turns into white mist, and 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. It supplies to the said drying chamber as a state, It is characterized by the above-mentioned.

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.

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.

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 It is preferable that the temperature is lower than the boiling point of the solvent of the active material solution, and the temperature is set high as long as the binding force between the current collector and the active material does not decrease.
According to such a configuration, in the drying of the current collector and the active material after applying the active material solution to the current collector of a non-aqueous electrolyte secondary battery such as a lithium ion battery, heating to about 200 ° C. or more is performed. The atmospheric pressure superheated steam that has been made transparent is lower than the boiling point of the solvent that is removed by vaporization (for example, 204 ° C.), and the temperature is set high so that the binding force between the current collector and the active material does not decrease Since it is supplied to the drying chamber in a state where the temperature is reduced to (for example, 180 ° C.), characteristics such as high osmotic force that are maintained even if the temperature of the atmospheric superheated steam that reaches the region of about 200 ° C. or higher is lowered. Taking advantage of it, the current collector (core material) generates heat instead of drying from the surface, and the solvent can be dried and evaporated from the inside while utilizing the heat storage effect, so the dry surface is kept in a good condition that does not burn. Efficient It is possible to dry, it is possible to dispense with the preheating zone.

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, Dry chang And a superheated steam and heated dry air supply line connected to the electromagnetic induction heating device, a humidity sensor for detecting humidity in the drying chamber, and the dry 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. Since 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%), the humidity in the drying chamber 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. .

Furthermore, a drying method according to the present invention is a drying method for drying a material to be dried in a drying chamber in order to solve the above-mentioned problem, wherein water or steam is heated by an electromagnetic induction heating device to about 200 ° C. or higher. The normal-pressure superheated steam that has become transparent in the above condition is generated, and the normal-pressure superheated steam that has been lowered to a predetermined temperature suitable for the material to be dried is supplied to the drying chamber and heated by a heated dry air supply device. The normal pressure heated dry air is supplied to the drying chamber, and the amount of the normal pressure dry air supplied to the drying chamber is adjusted so that the humidity in the drying chamber is lower than a predetermined humidity or within a predetermined humidity range. It is characterized by that.

According to such a configuration, normal pressure superheated steam that is transparent at about 200 ° C. or higher is generated by heating water or steam with an electromagnetic induction heating device, and this normal pressure superheated steam is used as a predetermined material suitable for the material to be dried. Since it is supplied to the drying chamber in a state lowered to the temperature, it can be dried at a predetermined temperature suitable for the material to be dried, and the temperature of the atmospheric superheated steam reaching an area of about 200 ° C. or higher at that time Since it is possible to make use of characteristics such as high penetrating power that are maintained even if the temperature is lowered, the material to be dried can be efficiently dried.
In addition, by adjusting the amount of atmospheric dry air supplied to the drying chamber, the humidity in the drying chamber is reduced to a predetermined humidity (for example, 20%) or less or within a predetermined humidity range (for example, 10% to 20%). Therefore, the humidity in the drying chamber can be kept substantially lower than the humidity (for example, 70 to 80%) in the drying chamber in a normal drying apparatus, so that drying of the material to be dried is more efficient. Can be done.
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 oxidation of the material to be dried can be promoted.

Further, in order to solve the above problems, the drying method according to the present invention provides the current collection 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 method for drying a body and an active material, wherein normal pressure dry air is supplied to an electromagnetic induction heating device to supply normal pressure dry air to the drying chamber, and the temperature of the inner wall of the drying chamber is set to 100 ° C. The preheating step in the drying chamber as described above, and the step of supplying atmospheric pressure steam and normal pressure dry air to the electromagnetic induction heating device and heating to generate normal pressure superheated steam that becomes transparent at about 200 ° C. or higher And the normal-pressure superheated water vapor | steam which became transparent at 200 degreeC or more is the temperature below the boiling point of the solvent of the said active material solution, and the range where the binding force of the said electrical power collector and the said active material does not fall The temperature was lowered to a preset temperature Drying the material to be dried having a step of supplying to the drying chamber as a state, and a step of setting the humidity in the drying chamber to a predetermined humidity or lower or within a predetermined humidity range by adjusting the supply amount of the atmospheric dry air Process,
It is provided with.

According to such a configuration, the atmospheric pressure heating dry air is supplied to the drying chamber and the temperature of the inner wall of the drying chamber is set to 100 ° C. or higher by the preheating process in the drying chamber, thereby suppressing the occurrence of condensation. it can.
In addition, the step of generating normal pressure superheated steam that became transparent at about 200 ° C. or higher in the drying process of the material to be dried, and the boiling point of the solvent that vaporizes and removes the normal pressure superheated steam (for example, 204 ° C.) By the step of supplying to the drying chamber as a state where the temperature is lower than the temperature and the temperature is lowered to a temperature set high (for example, 180 ° C.) within a range where the binding force between the current collector and the active material does not decrease, about 200 ° C. Utilizing the heat storage effect by heating the current collector (core material) rather than drying from the surface, taking advantage of the characteristics such as high permeability that can be maintained even when the temperature of the atmospheric superheated steam reaching the above range is lowered. Since the solvent can be dried and evaporated from the inside while being dried, the drying surface can be efficiently dried while maintaining a good dry surface, so that the preheating zone can be eliminated.
Furthermore, the humidity in the drying chamber is adjusted to a predetermined humidity (for example, 20%) or less or within a predetermined humidity range by adjusting the supply amount of atmospheric dry air supplied to the electromagnetic induction heating device in the drying process of the material to be dried. (For example, 10% to 20%), the humidity in the drying chamber can be kept significantly lower than the humidity in the drying chamber (eg, 70 to 80%) in a normal drying apparatus. Therefore, the current collector and the active material can be further 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, so that the current collector and the active material can be prevented from being oxidized.

As described above, according to the drying apparatus and the drying method of 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 the normal pressure superheated steam is used as the material to be dried. Since it is supplied to the drying chamber in a state lowered to a predetermined temperature suitable for the drying, it can be dried at a predetermined temperature suitable for the material to be dried, and at that time, the normal pressure reaching an area of about 200 ° C. or higher Since the characteristics such as high osmotic force maintained even if the temperature of the superheated steam is lowered can be utilized, the material to be dried can be efficiently dried, and the atmospheric pressure heated dry air supplied into the drying chamber Since the supply amount is adjusted and the humidity in the drying chamber is controlled to be equal to or lower than the predetermined humidity, the humidity in the drying chamber can be kept low, so that the drying of the material to be dried can be performed more efficiently. line A marked effect that it is possible.

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 (trade name: NMP) of Sankyo Chemical Co., Ltd. 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 at 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 box bodies in which a large number of through holes having a diameter of about 1 to 2 mm are formed 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 made higher 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

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. A drying apparatus characterized by that.
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.
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. The drying apparatus according to claim 1, wherein the temperature is lower than the boiling point of the solvent of the solution, and the temperature is set high in a range where the binding force between the current collector and the active material does not decrease.
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.
A drying method for drying a material to be dried in a drying chamber,
The normal-pressure superheated steam that is heated to water or steam by an electromagnetic induction heating device to generate normal-pressure superheated steam that becomes transparent at about 200 ° C. or more and is lowered to a predetermined temperature suitable for the material to be dried. The atmospheric pressure heated dry air heated by the heated dry air supply device is supplied to the drying chamber, and the amount of the atmospheric pressure dry air supplied to the drying chamber is adjusted. A drying method characterized in that the humidity in the drying chamber is lower than a predetermined humidity or in a predetermined humidity range.
A drying method 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 preheating step in the drying chamber in which normal pressure dry air is supplied to the electromagnetic induction heating device and heated to supply the drying chamber to the drying chamber so that the temperature of the inner wall of the drying chamber is 100 ° C. or higher;
Supplying and heating a mixed gas of normal pressure steam and normal pressure dry air to an electromagnetic induction heating device to generate normal pressure superheated steam that is transparent at about 200 ° C. or higher, and transparent at 200 ° C. or higher. The normal pressure superheated water vapor is reduced to a temperature that is lower than the boiling point of the solvent of the active material solution and set to a high temperature within a range in which the binding force between the current collector and the active material does not decrease A step of supplying the drying material to the drying chamber, and a step of drying the material to be dried by adjusting a supply amount of the atmospheric dry air so that the humidity in the drying chamber is equal to or lower than a predetermined humidity or within a predetermined humidity range. When,
A drying method comprising: