WO2013111647A1

WO2013111647A1 - Drying furnace unit and drying furnace

Info

Publication number: WO2013111647A1
Application number: PCT/JP2013/050641
Authority: WO
Inventors: 良夫近藤; 恭介勝山
Original assignee: 日本碍子株式会社
Priority date: 2012-01-23
Filing date: 2013-01-16
Publication date: 2013-08-01
Also published as: KR20140115328A; EP2808635A4; EP2808635A1; JPWO2013111647A1; CN104067080A

Abstract

A drying furnace unit (10) equipped with: a furnace body (12); a transport passage (14); a pipe structure (20) having first and second ventilation holes (21a, 22a); a hot breeze generation device (26); an exhaust blower (28); and a breeze direction switching valve (30). The breeze direction switching valve (30) is formed with first and second valves (31, 32). By switching the first and second valves (31, 32) the hot breeze generated by the hot breeze generation device (26) can be switched between flowing from the first ventilation hole (21a) to the second ventilation hole (22a) and flowing from the second ventilation hole (22a) to the first ventilation hole (21a).

Description

Drying furnace unit and drying furnace

The present invention relates to a drying furnace unit and a drying furnace.

Conventionally, a drying furnace for drying a sheet coated with slurry is known. For example, Patent Document 1 discloses a drying furnace in which four drying zones each having a carry-in port and a carry-out port are connected in a predetermined direction. The top plate of each drying zone is provided with an air supply port and an exhaust port. An air supply means for forcibly supplying air is attached to each air supply opening, and an exhaust means for forcibly discharging air is attached to each exhaust opening. In this drying furnace, the air flow in each drying zone is made to be the same and parallel to the sheet conveying direction. This air flow may be opposite to the sheet conveyance direction, but in order to efficiently remove the evaporated organic solvent, the air flow should be the same and parallel to the sheet conveyance direction. Preferred is described.

JP 2008-302297 A

However, the above-described drying furnace does not describe or suggest the technical idea of freely changing the air flow in each drying zone. In other words, since the air supply means is attached to the air supply port and the exhaust means is attached to the exhaust port, the air flow is fixed in the direction from the air supply port to the exhaust port. In order to reverse the air flow, the exhaust means is attached to the air supply port, and the air supply means is attached to the exhaust port. Then, the air flow is fixed in the direction from the exhaust port to the air supply port. . For this reason, the flow of air cannot be changed freely.

The main object of the present invention is to provide a drying furnace unit capable of freely changing the air flow and a drying furnace constituted by the drying furnace unit.

The drying oven unit of the present invention is
A furnace body;
A conveyance path that is provided so as to penetrate the furnace body in a predetermined direction, and a sheet coated with slurry on at least one side is conveyed in the predetermined direction;
First and second vent holes respectively provided at both ends of the transport passage so that atmospheric gas flows along the slurry application surface of the sheet;
Air supply means connected to the first vent and the second vent;
Air from the air supply means is flowed from the first vent to the second vent along the application surface of the sheet, or along the application surface of the sheet from the second vent to the first vent. Wind direction switching means for switching whether to send air from the air supply means;
It is equipped with.

In this drying furnace unit, by switching the air direction switching means, the air is supplied from the air supply means along the coating surface of the sheet from the first vent to the second vent, or conversely, the second vent is connected to the second vent. It is possible to set whether to send the air from the air supply means to the one air vent along the sheet application surface. That is, the atmosphere gas flow can be freely changed by switching the wind direction switching means.

Note that the air supply means may supply hot air (for example, 60 to 150 ° C.) or cold air (for example, room temperature or 40 to 50 ° C.). The atmosphere gas is not particularly limited, and examples thereof include air and an inert gas (such as nitrogen).

It is preferable that the drying furnace unit of the present invention includes an infrared heater provided at a position facing the coating surface of the sheet in the conveyance path. In this way, when it is difficult to dry the slurry application surface only by air blowing, the slurry application surface can be dried in a short time by using an infrared heater together. As such an infrared heater, for example, the outer circumference of the filament is concentrically covered by a plurality of tubes functioning as a filter that absorbs infrared rays having a wavelength exceeding 3.5 μm, and the surface temperature of the infrared heater is between these tubes. In this case, a cooling fluid flow path that suppresses the increase in the temperature (see Japanese Patent No. 4790092) may be used.

It is preferable that the drying furnace unit of the present invention includes air volume adjusting means for adjusting the air volume of the air supply means. If it carries out like this, not only the wind direction of ventilation but the air volume can be changed freely.

In the drying furnace unit of the present invention, the sheet may have a slurry applied to both sides thereof, and the first and second vent holes may be provided corresponding to the respective slurry application surfaces. In this way, the sheet coated with the slurry on both sides can be dried at the same time, so the time is shortened compared to the case of drying one by one. As a result, production efficiency increases.

The drying furnace of the present invention is a unit in which a plurality of the above-described drying furnace units are connected such that each conveyance passage is continuous along the predetermined direction.

In this drying furnace, the flow of the atmosphere gas can be freely changed for each drying furnace unit by switching the air direction switching means of each drying furnace unit. For example, the flow of the air flow between adjacent drying furnace units can be the same direction or the reverse direction. Moreover, when making it a reverse direction, the flow of ventilation can be made to collide or the flow of ventilation can be separated.

In the drying furnace of the present invention, the drying furnace units arranged at both ends of the plurality of drying furnace units may be set so that the air direction of the air flow is directed from outside to inside by the air direction switching means. If it carries out like this, ventilation will become difficult to blow out from the conveyance path of the drying furnace unit arrange | positioned at the other end also from the conveyance path of the drying furnace unit arrange | positioned at one end of a drying furnace. As a result, the environment of the room in which the drying furnace is installed can be favorably maintained.

The drying furnace of the present invention includes a detecting means for detecting the amount of solvent evaporated from the slurry in each drying furnace unit, and when the amount of solvent evaporation exceeds a predetermined value for a plurality of continuous drying furnace units, Control means for controlling the wind direction switching mechanism so that the wind direction of the air blown from the furnace unit is the same direction. If the solvent evaporation amount of a plurality of continuous drying furnace units exceeds a predetermined value, assuming that the air flow direction of those drying furnace units is reversed, a place where the flow of the atmospheric gas stagnates is generated and evaporated there The accumulated solvent may accumulate. However, since the airflow direction of these drying furnace units is controlled to be the same in this case, the location where the evaporated solvent accumulates is unlikely to occur.

1 is a longitudinal sectional view of a drying furnace unit 10. 3 is a longitudinal sectional view of an infrared heater 36. FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. It is explanatory drawing of the wind direction switching of the drying furnace unit 10, (a) is when a hot air flows from the 1st vent 21a to the 2nd vent 22a, (b) is a 1st vent from the 2nd vent 22a. It is explanatory drawing when flowing to 21a. It is explanatory drawing of the drying furnace. FIG. 5 is an explanatory diagram showing a relationship between an evaporation curve and a wind direction of each of the drying furnace units U1 to U7 constituting the drying furnace 70. 2 is a longitudinal sectional view of a drying furnace unit 110. FIG. It is explanatory drawing of the drying furnace 170. FIG. It is explanatory drawing of the modification of the drying furnace.

Next, a preferred embodiment of the present invention will be described with reference to the drawings. 1 is a longitudinal sectional view of the drying furnace unit 10, FIG. 2 is a longitudinal sectional view of the infrared heater 36, and FIG. 3 is a sectional view taken along the line AA of FIG.

The drying furnace unit 10 includes a furnace body 12, a transfer passage 14, a pipe structure 20 having first and

second vent holes

21a and 22a, a hot air generator 26, an exhaust blower 28, and a wind direction switching valve 30. And an infrared heater 36.

The furnace body 12 is a heat insulating structure formed in a substantially rectangular parallelepiped shape, and has

openings

14a and 14b on the front end face 12a and the rear end face 12b, respectively. The furnace body 12 has a length from the front end surface 12a to the rear end surface 12b of 2 to 6 m.

The conveyance passage 14 is a passage from the opening 14a to the opening 14b, and penetrates the furnace body 12 in the horizontal direction. The sheet 60 coated with the slurry on one side passes through the conveyance path 14. Specifically, the sheet 60 is loaded from the opening 14a with the surface (slurry coating surface) 62 on which the slurry is applied facing upward, travels in the furnace body 12 in the horizontal direction, and is unloaded from the opening 14b. .

The pipe structure 20 penetrates in the vertical direction at a location near the rear end surface 12b in the ceiling of the furnace body 12 and the first pipe portion 21 that penetrates in the vertical direction at a location near the front end surface 12a in the ceiling of the furnace body 12. The second pipe part 22 to be connected, the third pipe part 23 connecting the upper end of the first pipe part 21 and the upper end of the second pipe part 22, the intermediate position of the first pipe part 21 and the intermediate position of the second pipe part 22 And a fourth pipe portion 24 that connects the two. That is, the third pipe portion 23 and the fourth pipe portion 24 are passages that connect the first pipe portion 21 and the second pipe portion 22 in parallel. The first pipe portion 21 is bent so as to be bent in the furnace body 12 so that the vicinity of the lower end faces the horizontal direction. For this reason, the 1st vent 21a which is the lower end opening of the 1st pipe part 21 is the state opened toward the rear-end surface 12b. The second pipe portion 22 is processed so that the vicinity of the lower end bent inside the furnace body faces the horizontal direction. For this reason, the 2nd vent 22a which is the lower end opening of the 2nd pipe part 22 is the state opened toward the front end surface 12a. The first vent 21a and the second vent 22a are provided so as to face each other. The heights may be different, but are usually provided to be the same. For this reason, the air flowing out from one of the first and

second vent holes

21a, 22a flows into the other, and the flow of the air at that time is in a direction along the slurry application surface 62 of the sheet 60.

The hot air generator 26 is attached to the fourth pipe portion 24 and supplies hot air to the inside of the fourth pipe portion 24. The hot air generator 26 can adjust the air volume.

The exhaust blower 28 is attached to the third pipe portion 23 and has a function of discharging the gas inside the third pipe portion 23 to the outside. This exhaust blower 28 can also adjust the air volume.

The air direction switching valve 30 is provided at the joint between the first valve 31 provided at the joint between the first pipe part 21 and the fourth pipe part 24 and the second pipe part 22 and the fourth pipe part 24. And a second valve 32. The first valve 31 communicates the first pipe portion 21 and the fourth pipe portion 24 and at the same time shuts off the communication between the first pipe portion 21 and the third pipe portion 23 (see the solid line in FIG. 1, the air supply position). Any of the positions where the communication between the first pipe portion 21 and the fourth pipe portion 24 is blocked and the first pipe portion 21 and the third pipe portion 23 are communicated (see the dotted line in FIG. 1, exhaust position). Can be switched. The second valve 32 shuts off the communication between the second pipe part 22 and the fourth pipe part 24 and at the same time communicates the second pipe part 22 and the third pipe part 23 (refer to the solid line in FIG. 1, referred to as the exhaust position). ) And the second pipe portion 22 and the fourth pipe portion 24 and the position where the communication between the second pipe portion 22 and the third pipe portion 23 is blocked (refer to the dotted line in FIG. 1, referred to as the air supply position). It can be switched to either. The

valves

31 and 32 may be switched manually, or may be switched electrically using an electromagnetic solenoid or the like. Further, although not shown, a circulation piping system may be added between the pipes so as to supplement a part of the exhaust with a part of the supply air.

A plurality of infrared heaters 36 are attached near the ceiling of the furnace body 12. The longitudinal direction of each infrared heater 36 is attached so as to be orthogonal to the transport direction. As shown in FIGS. 2 and 3, the infrared heater 36 includes a heater body 42 formed so that the inner tube 40 surrounds the filament 38, an outer tube 44 formed so as to surround the heater body 42, and an outer tube 44. A bottomed cylindrical cap 46 that is airtightly fitted to both ends of the tube 44, and a flow path 48 that is formed between the heater body 42 and the outer tube 44 and through which the cooling fluid can flow. The filament 38 is energized and heated to 700 to 1200 ° C., and emits infrared rays having a peak at a wavelength around 3 μm. The electrical wiring 38 a connected to the filament 38 is led out to the outside airtightly through a wiring lead-out portion 46 a provided in the cap 46. The inner tube 40 is made of quartz glass, borosilicate crown glass, or the like, and functions as a filter that passes infrared rays having a wavelength of 3.5 μm or less and absorbs infrared rays having a wavelength exceeding 3.5 μm. The heater body 42 is supported by holders 50 arranged at both ends inside the cap 46. As with the inner tube 40, the outer tube 44 is made of quartz glass, borosilicate crown glass, or the like, and passes through infrared rays having a wavelength of 3.5 μm or less and absorbs infrared rays having a wavelength exceeding 3.5 μm. Function. Each cap 46 has a fluid inlet / outlet 46b. The flow path 48 is configured such that the cooling fluid flows from one fluid inlet / outlet 46b to the other fluid inlet / outlet 46b. The cooling fluid flowing through the flow channel 48 is, for example, air or an inert gas, and cools each of the

tubes

40 and 44 by contacting the inner tube 40 and the outer tube 44 to remove heat. In the infrared heater 36, when infrared light having a peak near 3 μm is emitted from the filament 38, infrared light having a wavelength of 3.5 μm or less passes through the inner tube 40 and the outer tube 44 and passes through the conveyance path. The slurry is applied to the slurry application surface 62 of the sheet 60. Infrared light having this wavelength is said to be excellent in the ability to break hydrogen bonds of the organic solvent contained in the slurry application surface 62 of the sheet 60, and can efficiently evaporate the organic solvent. On the other hand, the inner tube 40 and the outer tube 44 absorb infrared rays having a wavelength exceeding 3.5 μm, but are cooled by the cooling fluid flowing through the flow path 48, and thus are less than the ignition point of the organic solvent evaporating from the slurry application surface 62. It is possible to maintain the temperature.

Such an infrared heater 36 is disposed in an internal space of an arch-shaped recess 52 provided in a reflector near the ceiling of the furnace body 12. Similarly to the infrared heater 36, the arch-shaped recess 52 is formed so as to extend in a direction orthogonal to the conveyance direction, and has a cross-sectional shape that is a curved shape such as a parabola, an elliptical arc, or an arc, and has a focal point or a center position. Infrared heater 36 is arranged. As a result, infrared light having a wavelength of 3.5 μm or less emitted from the infrared heater 36 is reflected by the arch-shaped recess 52 and efficiently irradiated onto the slurry application surface 62.

Next, the air direction switching of the drying furnace unit 10 will be described. FIG. 4 is an explanatory diagram of the air direction switching of the drying furnace unit 10, (a) shows when hot air flows from the first vent 21 a to the second vent 22 a, and (b) shows hot air from the second vent 22 a. It is explanatory drawing when flowing to 1 vent 21a.

When flowing hot air from the first vent 21a to the second vent 22a, as shown in FIG. 4A, the first valve 31 is set to the air supply position and the second valve 32 is set to the exhaust position. Specifically, the first valve 31 is set at a position where the first pipe portion 21 and the fourth pipe portion 24 communicate with each other and the communication between the first pipe portion 21 and the third pipe portion 23 is blocked. Further, the second valve 32 is set at a position where the communication between the second pipe portion 22 and the fourth pipe portion 24 is blocked and the second pipe portion 22 and the third pipe portion 23 are communicated. Then, the hot air supplied from the hot air generator 26 to the fourth pipe part 24 is blown out from the first vent 21 a through the first pipe part 21. On the other hand, the exhaust blower 28 exhausts gas from the third pipe portion 23 via the second vent 22 a and the second pipe portion 22. As a result, hot air flows into the furnace body 12 from the first vent 21a to the second vent 22a.

When flowing hot air from the second vent 22a to the first vent 21a, as shown in FIG. 4 (b), the second valve 32 is set to the supply position and the first valve 31 is set to the exhaust position. Specifically, the second valve 32 is set at a position where the second pipe portion 22 and the fourth pipe portion 24 communicate with each other and the communication between the second pipe portion 22 and the third pipe portion 23 is blocked. Further, the first valve 31 is set at a position where the communication between the first pipe part 21 and the fourth pipe part 24 is blocked and the first pipe part 21 and the third pipe part 23 are communicated. Then, the hot air supplied from the hot air generator 26 to the fourth pipe portion 24 is blown out from the second vent 22 a through the second pipe portion 22. On the other hand, the exhaust blower 28 exhausts gas from the third pipe part 23 via the first vent 21 a and the first pipe part 21. As a result, hot air flows into the furnace body 12 from the second vent 22a to the first vent 21a.

Next, a description will be given of a drying furnace 70 in which a plurality of such drying furnace units 10 are connected so that the transport passages 14 are connected in a straight line along the horizontal direction. FIG. 5 is an explanatory view of the drying furnace 70, and FIG. 6 is an explanatory view showing the relationship between the evaporation curve and the wind direction of each drying furnace unit 10 constituting the drying furnace 70.

As shown in FIG. 5, the drying furnace 70 is formed by connecting one front end face 12 a and the other rear end face 12 b with bolts for adjacent drying furnace units 10. At this time, the opening 14a of one front end surface 12a and the opening 14b of the other rear end surface 12b are kept airtight by a packing (not shown). The material of the packing may be any material that can withstand an organic solvent, and examples thereof include polytetrafluoroethylene. If the sealing property of the packing 18 is good, the bolt connection may be omitted. Moreover, although the drying furnace 70 is installed in the drying furnace installation chamber, the exhaust blower 28 may be installed outside the drying furnace installation chamber. Even if installed in the room, the blower outlet and the exhaust port to the outside of the building are connected by a duct, so that the exhaust from the exhaust blower 28 is not released into the drying furnace installation room.

Now, as shown in FIG. 6, it is assumed that a drying furnace 70 is configured by connecting seven drying furnace units 10. For convenience, each drying furnace unit 10 will be referred to as a drying furnace unit U1, a drying furnace unit U2,. The sheet 60 is unwound from the roll 72 disposed at the left end of the drying furnace 70, and immediately before being loaded into the drying furnace 70, the slurry is applied to the upper surface by a coater (not shown) and passes through the opening 14a of the drying furnace unit U1. It is carried into the drying furnace 70. Thereafter, the sheet 60 passes through each of the drying furnace units U1 to U7, whereby the organic solvent evaporates from the slurry application surface 62, and the evaporated organic solvent is discharged to the outside by the exhaust blower 28, and finally the drying furnace unit. It is carried out from the opening 14b of U7 and wound around a roll 74 installed at the right end of the drying furnace 70. The organic solvent evaporates from the slurry application surface 62 due to the action of infrared rays irradiated from the infrared heater 36 and hot air supplied from the hot air generator 26.

Incidentally, it is assumed that a numerical simulation is performed in advance when the sheet 60 having the slurry application surface 62 is dried using such a drying furnace 70, and the obtained evaporation curve has a profile shown in FIG. This evaporation curve shows that the sheet temperature does not rise sufficiently immediately after the sheet 60 is carried into the drying furnace unit U1, so the amount of evaporation of the organic solvent is small, and thereafter the evaporation amount from the drying furnace unit U2 to the drying furnace unit U4. Is very large, and after the drying furnace unit U5, since almost all of the organic solvent has evaporated, the amount of evaporation is small. In this evaporation curve, in a plurality of drying furnace units U2 to U4 that exceed the evaporation amount threshold value indicated by the dotted line, if all the hot air directions are not the same, there is a possibility that a solvent pool will occur. That is, when there are air dryers in which the direction of hot air is different from that of other units in the drying furnace units U2 to U4, the flow of air is different at locations where the directions of the hot air are different (for example, where the hot air collides or moves away). A hazy spot may occur and the evaporated solvent may accumulate there. However, here, in order to make the direction of the hot air of these drying furnace units be the same direction, the location where the evaporated solvent accumulates is unlikely to occur. In normal design, each unit is considered independently, and the policy is to ensure the amount of hot air necessary to dilute the volatile solvent within that range. Even in this case, in an area where the amount of solvent evaporation is large, it is desirable to improve safety by using a mechanism that links the supply and exhaust of each unit as described above.

Further, in the drying furnace units U1 and U7 located at both ends of the drying furnace 70, the direction of the hot air is set in a direction from the outside to the inside. For this reason, it becomes difficult for hot air to blow out from the opening 14a of the drying furnace unit U1 and from the opening 14b of the drying furnace unit U7. In this case, since the wind directions of the two are reversed, there is always a connection point where the wind direction is opposite in the furnace, but the connection point is set at a position where the amount of solvent evaporation is small as described above. It is desirable. However, since the evaporation curve differs depending on the slurry to be applied, it is necessary to change the connection point to an appropriate position according to the type of the slurry. In the present invention, since the direction of wind can be changed for each drying furnace unit, such an operation becomes possible.

The sheet 60 having the slurry application surface 62 is not particularly limited, and for example, a sheet coated with an electrode for a lithium ion secondary battery may be used. Examples of such a sheet include a sheet obtained by applying an electrode material slurry obtained by kneading a positive electrode active material (or a negative electrode active material) together with a binder, a conductive material, and an organic solvent onto a metal sheet such as aluminum or copper. Or you may use the sheet | seat made from the baking ceramic which apply | coated the unfired ceramic molded object. Examples of such sheets include those obtained by applying a slurry obtained by kneading ceramic particles in a binder and water (or an organic solvent) onto a sheet made of fired ceramics.

According to the drying furnace unit 10 of the present embodiment described above, whether hot air is caused to flow along the slurry application surface 62 of the sheet 60 from the first vent 21a to the second vent 22a by switching the air direction switching valve 30. On the contrary, it can be set whether hot air is made to flow along the slurry application surface 62 of the sheet 60 from the second vent 22a to the first vent 21a. That is, the air flow can be freely changed by switching the wind direction switching valve 30.

Moreover, since the infrared heater 36 is provided, when it is difficult to dry the slurry application surface 62 only with hot air, the slurry application surface 62 can be dried in a short time by using the infrared heater 36 together. . In particular, since the infrared heater 36 irradiates infrared rays having a wavelength of 3.5 μm or less and keeps the heater surface temperature below the ignition point of the organic solvent, the organic solvent can be efficiently evaporated, and the organic solvent ignites. There is no risk of doing so.

Furthermore, since the hot air generator 26 and the exhaust blower 28 can adjust the air volume, not only the direction of the hot air but also the air volume can be freely changed.

Furthermore, since the drying furnace 70 is formed by connecting a plurality of drying furnace units U1 to U7 so that each conveyance path is continuous along the conveyance direction of the sheet 60, the wind direction switching valve of each drying furnace unit U1 to U7. By switching 30, the air flow can be freely changed for each of the drying furnace units U 1 to U 7. For example, the flow of hot air between adjacent drying furnace units can be in the same direction or in the reverse direction. Moreover, when making it a reverse direction, the flow of a hot air can be made to collide, or the flow of a hot air can be separated. Based on the evaporation curve, the flow of hot air in each of the drying furnace units U1 to U7 can be adjusted so as not to cause a pool of solvents.

Moreover, since the drying furnace units U1 and U7 arranged at both ends of the drying furnace 70 are set so that the direction of the hot air is directed from the outside to the inside, the drying furnace unit U1 is also fed from the transport passage 14 of the drying furnace unit U1. Hot air is less likely to be blown out from the U7 conveyance path 14. As a result, the environment of the drying furnace installation chamber in which the drying furnace 70 is installed can be favorably maintained.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

For example, in the above-described embodiment, the drying furnace unit 10 and the drying furnace 70 that dry the sheet 60 coated with the slurry on one side are exemplified. However, as shown in FIGS. 7 and 8, the sheet 160 coated with the slurry on both sides. The drying oven unit 110 and the drying oven 170 may be used. In addition, the same code | symbol is attached | subjected about the same component as the drying furnace unit 10 and the drying furnace 70 mentioned above among the drying furnace unit 110 and the drying furnace 170, and the description is abbreviate | omitted. The drying furnace unit 110 shown in FIG. 7 is used for drying the sheet 160 whose both surfaces are the slurry application surfaces 162. The drying furnace unit 110 includes a pipe structure 20 having first and

second vent holes

21a and 22a, a hot air generator 26, an exhaust blower 28, a wind direction switching valve 30, and an infrared heater 36, and each slurry. It is provided corresponding to the coating surface 162. Further, the wind direction switching can be performed by the first and

second valves

31 and 32 of the wind direction switching valve 30 as in the above-described embodiment.

The drying furnace 170 shown in FIG. 8 is a unit in which a plurality of such drying furnace units 110 are connected so that each conveyance passage 14 is connected in a straight line along the horizontal direction. The connection method is the same as that of the drying furnace 70. Also here, for convenience, each drying furnace unit 110 is referred to as a drying furnace unit U1, a drying furnace unit U2,..., And a drying furnace unit U7 in order from the left. The sheet 160 is unwound from the roll 72 disposed at the left end of the drying furnace 170, and immediately before being loaded into the drying furnace 70, slurry is applied to both the upper and lower surfaces by a rotor (not shown) and passes through the opening 14a of the drying furnace unit U1. Then, it is carried into the drying furnace 70. Thereafter, the sheet 160 passes through each of the drying furnace units U1 to U7, whereby the organic solvent evaporates from the upper and lower slurry application surfaces 162, and the evaporated organic solvent is discharged to the outside by each exhaust blower 28. It is unloaded from the opening 14b of the drying furnace unit U7 and wound around a roll 74 installed at the right end of the drying furnace 170. Also in this case, similarly to the drying furnace 70 described above, the direction of hot air in each of the drying units U1 to U7 is determined based on the evaporation curve obtained by numerical simulation. Further, in the drying furnace units U1 and U7 located at both ends of the drying furnace 170, by setting the direction of the hot air in the direction from the outside to the inside, the opening 14b of the drying furnace unit U7 is also set from the opening 14a of the drying furnace unit U1. The hot air is difficult to blow out. According to the drying furnace unit 110 and the drying furnace 170 described above, the sheet 160 having both surfaces coated with the slurry can be simultaneously dried, so that the time is shortened as compared with the case where each sheet is dried one by one. As a result, production efficiency increases.

In the embodiment described above, the hot air direction of each of the drying furnace units U1 to U7 is determined based on the evaporation curve, but the hot air direction may be changed while the sheet 60 is being dried. In this case, the wind direction may be changed manually or automatically. An example of the case where the wind direction is automatically changed will be described below with reference to FIG. A sensor S for detecting the amount of solvent evaporation evaporated from the slurry application surface 62 is attached to each drying furnace unit 10 constituting the drying furnace 70. In addition, solenoid valves are employed as the first and

second valves

31 and 32. Further, the controller C is prepared, each sensor S is connected to the input port of the controller C, and the first and

second valves

31 and 32 are connected to the output port. As a result, a signal related to the amount of solvent evaporation output from each sensor S is input to the controller C. Further, a drive signal is output from the controller C to the first and

second valves

31 and 32. Then, the controller C determines whether or not the solvent evaporation amount exceeds a predetermined threshold value for a plurality of continuous drying furnace units, and when it exceeds, the direction of hot air of the plurality of drying furnace units becomes the same direction. The first and

second valves

31 and 32 are controlled. If the amount of solvent evaporation in a plurality of continuous drying furnace units exceeds the threshold, assuming that the direction of hot air in those drying furnace units is reversed, a location where the air flow stagnates occurs and the solvent evaporated there May accumulate. However, here, since the direction of the hot air of these drying furnace units is controlled to be the same direction, the location where the evaporated solvent accumulates hardly occurs. The sensor S may be selected depending on the organic solvent used in the slurry. For example, a hydrocarbon (HC) sensor is selected for a hydrocarbon solvent, and an alcohol sensor is selected for an alcohol solvent. Good.

In the above-described embodiment, the conveying path 14 may be provided with several support rollers that support the sheet 60 from below. In this way, it is possible to prevent the sheet 60 from being bent by gravity. However, when both surfaces of the sheet 160 are the slurry application surface 162 as shown in FIG. 7 and FIG. 8, if the support roller is provided, the slurry application surface 62 comes into contact with the support roller and unintended irregularities are generated. It is preferable not to provide a roller.

In the embodiment described above, the infrared heater 36 is provided on the ceiling of the furnace body 12. However, the infrared heater 36 is omitted when the slurry application surface 62 of the sheet 60 is thin and can be sufficiently dried only with hot air. May be.

In the above-described embodiment, the outer periphery of the filament 38 is concentrically covered by the plurality of

tubes

40 and 44 that function as a filter that absorbs infrared rays having a wavelength exceeding 3.5 μm as the infrared heater 36. , 44 in which a cooling fluid flow path 48 that suppresses the rise in the surface temperature of the infrared heater 36 is formed, but other infrared heaters may be used.

In the above-described embodiment, the drying furnace 70 has a plurality of drying furnace units 10 connected in series, but the drying furnace unit 10 may be used alone as a drying furnace.

In the above-described embodiment, air is used as the atmospheric gas of each drying furnace unit 10, but an inert gas such as nitrogen may be used instead of air.

In the above-described embodiment, the hot air generator 26 is used as the air supply means. However, the hot air generator 26 is not particularly limited to this. For example, a cold air generator that generates cold air of 40 to 50 ° C. may be used.

This application is based on Japanese Patent Application No. 2012-10631 filed on January 23, 2012, and the entire contents of which are incorporated herein by reference.

INDUSTRIAL APPLICABILITY The present invention relates to an industry in which a sheet coated with a slurry needs to be dried, for example, a battery industry for producing an electrode coating film of a lithium ion secondary battery, or a ceramic for producing a ceramic laminate comprising two layers of ceramic sintered bodies It can be used in industry, film industry for manufacturing optical film products, and the like.

10 Drying furnace unit, 12 furnace body, 12a front end face, 12b rear end face, 14 transport passage, 14a opening, 14b opening, 20 pipe structure, 21 first pipe part, 21a first vent, 22 second pipe part, 22a 2nd vent, 23 3rd pipe part, 24 4th pipe part, 26 hot air generator, 28 exhaust blower, 30 air direction switching valve, 31 1st valve, 32 2nd valve, 36 infrared heater, 38 filament, 38a Electrical wiring, 40 inner pipe, 42 heater body, 44 outer pipe, 46 cap, 46a wiring outlet, 46b fluid inlet / outlet, 48 flow path, 50 holder, 52 arched recess, 60 sheet, 62 slurry application surface, 70 drying Furnace, 72 rolls, 74 rolls, 110 drying furnace units, 160 shi DOO, 162 slurry coated surface, 170 drying oven, C controller, S sensors, U1 ~ U7 drying oven unit.

Claims

A furnace body;
A conveyance path that is provided so as to penetrate the furnace body in a predetermined direction, and a sheet coated with slurry on at least one side is conveyed in the predetermined direction;
First and second vent holes respectively provided at both ends of the transport passage so that atmospheric gas flows along the slurry application surface of the sheet;
Air supply means connected to the first vent and the second vent;
The air is supplied from the air supply means along the sheet application surface from the first vent to the second vent, or along the sheet application surface from the second vent to the first vent. Wind direction switching means for switching whether to send air from the air supply means;
Drying oven unit equipped with.
A drying furnace unit according to claim 1,
A drying furnace unit comprising an infrared heater provided at a position facing the coating surface of the sheet in the conveyance path.
A drying furnace unit according to claim 1 or 2,
A drying furnace unit comprising air volume adjusting means for adjusting the air volume of the air supply means.
The sheet is a slurry coated on both sides,
The first and second vent holes are provided corresponding to each slurry application surface,
The drying furnace unit according to any one of claims 1 to 3.
A drying furnace in which a plurality of the drying furnace units according to any one of claims 1 to 4 are connected so that each conveyance path is continuous along the predetermined direction.
The drying furnace units disposed at both ends of the plurality of drying furnace units are set so that the air direction of the air flow is directed from the outside to the inside by the air direction switching means.
The drying furnace according to claim 5.
A drying furnace according to claim 5 or 6,
Detecting means for detecting the amount of solvent evaporated from the slurry in each drying furnace unit;
When the solvent evaporation amount exceeds a predetermined value for a plurality of continuous drying furnace units, control means for controlling the air direction switching mechanism so that the air direction of the air of the plurality of drying furnace units is the same direction;
Drying furnace equipped with.