JP6824772B2 - Drying device and manufacturing method of dried body - Google Patents

Description

The present invention relates to a drying apparatus and a method for producing a dried product.

Conventionally, a drying device for drying an object to be dried using infrared rays has been known (see, for example, Patent Document 1). The drying device described in Patent Document 1 dries the coating film using an infrared panel heater arranged in the furnace.

Japanese Patent No. 3897456

By the way, when the object to be dried contains a plurality of kinds of substances, the susceptibility to heating by infrared rays may differ between the plurality of kinds of substances due to the difference in the absorption rate of infrared rays between the plurality of kinds of substances. In this case, the temperature in the object to be dried may fluctuate due to the irradiation of infrared rays, for example, the place where many substances that are easily heated are unevenly distributed in the object to be dried tends to be high in temperature. When the temperature fluctuates, the drying speed fluctuates, which may cause problems such as non-uniform thickness of the object to be dried after drying.

The present invention has been made to solve such a problem, and an object of the present invention is to reduce variations in temperature during drying of an object to be dried containing a plurality of kinds of substances.

The present invention has taken the following measures to achieve the above-mentioned main object.

The drying apparatus of the present invention
A drying device that dries the object to be dried.
With the furnace body
A transport means for transporting the object to be dried in the transport direction in the internal space of the furnace body, and
One or more infrared heaters capable of radiating infrared rays to the object to be dried carried in the internal space of the furnace body, and
In the internal space of the furnace body, the irradiation section in which the infrared rays emitted from the infrared heater are irradiated to the object to be dried and the non-irradiation section in which the object to be dried is not irradiated are alternately arranged along the transport direction. A shielding member that shields infrared rays from the infrared heater so that there are a plurality of them.
It is equipped with.

In this drying device, the infrared rays from the infrared heater are shielded by the shielding member, so that the irradiated section and the non-irradiated section alternately exist in the internal space of the furnace body along the transport direction of the object to be dried. There are a plurality of irradiated sections and non-irradiated sections. Therefore, when the object to be dried is transported through the internal space of the furnace body, the object to be dried is dried while alternately passing through the irradiated section and the non-irradiated section a plurality of times. Here, when the object to be dried contains a plurality of kinds of substances, the temperature in the object to be dried varies due to the irradiation of infrared rays as described above while the object to be dried passes through the irradiation section, and a local temperature difference occurs. May spread. On the other hand, while the object to be dried passes through the non-irradiated section, the variation in temperature in the object to be dried becomes small due to heat conduction. Therefore, in the drying apparatus of the present invention, the irradiation section and the non-irradiation section are alternately present, so that the temperature variation at the time of drying the object to be dried can be reduced as compared with the case where the non-irradiation section does not exist, for example. ..

Here, the "irradiation section" is a section in which infrared rays from the heating element of the infrared heater can reach the object to be dried linearly without being reflected, that is, the shielding member is formed on a straight line between the heating element and the object to be dried. The section does not exist. Further, in the "non-irradiated section", the shielding member is placed on a section in which infrared rays from the heating element of the infrared heater cannot be linearly reached without being reflected, that is, on a straight line between the heating element and the object to be dried. It is an existing section.

The drying apparatus of the present invention
A partition wall is provided between the object to be dried carried in the internal space of the furnace body and the one or more infrared heaters, and the shielding member constitutes a part of the partition wall, and the partition wall is formed. May have a transmissive member which is arranged so as to close the portion where the shielding member does not exist, transmits infrared rays from the infrared heater, and allows the irradiation section to be irradiated with infrared rays. In this case, the partition wall may partition the internal space of the furnace body. Further, the permeation member may partition the internal space of the furnace body. In this way, the shielding member can also be used as a part of the partition wall that partitions the internal space of the furnace body. Further, the shielding member may reflect infrared rays. In this way, overheating of the partition wall can be suppressed as compared with the case where the shielding member absorbs infrared rays, for example.

In the drying apparatus of the present invention, a plurality of the infrared heaters are arranged along the transport direction, and the shielding member is arranged so as to cover only a part of the periphery of each of the plurality of infrared heaters. You may be. In this case, the infrared heater has a heating element that radiates infrared rays when heated, and a transmission tube that surrounds the heating element and transmits infrared rays from the heating element, and the shielding member. May be disposed on the surface of the transmission tube.

In the drying apparatus of the present invention in which a shielding member is provided for each of the infrared heaters, the shielding member may reflect infrared rays. In this way, the infrared rays reflected by the shielding member are easily used for at least one of heating of the heating element and heating of the object to be dried, so that energy efficiency is improved.

The method for producing a dried product of the present invention is
The object to be dried is dried by transporting the object to be dried so as to alternately pass through an irradiation section in which the object to be dried is irradiated with infrared rays and a non-irradiation section in which the object to be dried is not irradiated. Drying process,
Is included.

In this method for producing a dried product, the object to be dried is dried while being transported so as to alternately pass through the irradiated section and the non-irradiated section a plurality of times, respectively. Therefore, as in the drying apparatus of the present invention described above, the irradiation section The magnitude of the temperature variation in the object to be dried caused by the above can be reduced in the non-irradiated section. Therefore, it is possible to reduce the temperature variation during the drying process of the object to be dried containing a plurality of kinds of substances. Further, this makes it possible to suppress problems caused by temperature variations such as non-uniform thickness of the dried body. The dried product may be made into a dried product by performing this drying step, or the dried product may be made into a dried product by performing another step (for example, drying with hot air) after this drying step. .. The method for producing a dried product of the present invention can be carried out using, for example, the above-mentioned drying apparatus of the present invention.

Schematic cross-sectional view of the drying apparatus 1. A cross-sectional view taken along the line AA of FIG. FIG. 2 is a partial cross-sectional view of the BB cross section of FIG. Explanatory drawing of the irradiation section 55 and the non-irradiation section 56. Explanatory drawing of an infrared heater 140 provided with a shielding member 152 of a modification. The explanatory view of the infrared heater 240 provided with the shielding member 252 of the modification. The explanatory view of the shielding member 352 of the modification.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a drying apparatus 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a partial cross-sectional view of the BB cross section of FIG. FIG. 4 is an enlarged view of a part of FIG. 1, and is an explanatory view of an irradiated section 55 and a non-irradiated section 56. In FIG. 2, the nozzle 60 and the guide roll 30 are not shown. In this embodiment, the vertical direction, the horizontal direction, and the front-rear direction are as shown in FIGS. The drying device 1 is a device that dries the object to be dried 34 while conveying the object to be dried 34 (see FIG. 2) placed on the belt 22 of the belt conveyor 20 in the conveying direction. In the present embodiment, the transport direction is from the front to the rear. The drying device 1 includes an infrared drying furnace 1a, a hot air drying furnace 1b, a belt conveyor 20, and a control device 90. The drying device 1 does not have to be provided with a hot air drying furnace 1b.

The object to be dried 34 contains a plurality of kinds of substances. The object to be dried 34 may contain, for example, raw material particles (for example, at least one of ceramic particles or metal particles), a binder, and a solvent. In the present embodiment, the object to be dried 34 is a molded body of a slurry containing these substances, and is a film-like body extending in the front-back and left-right directions. When the object to be dried 34 is subjected to a drying step using the drying device 1, the solvent in the object to be dried 34 is volatilized and removed, and the object to be dried 34 is dried. The dried object 34, that is, the dried product, is subsequently fired to volatilize and remove the binder, for example, to obtain the final product (fired product). Examples of products obtained by using such an object to be dried 34 include electronic parts and sensor elements. The film thickness of the object to be dried 34 after drying may be 0.05 mm or more and 3 mm or less.

The infrared drying furnace 1a is a device for drying an object to be dried 34 using infrared rays, and includes a furnace body 10, an infrared heater 40, a partition wall 50, a nozzle 60, and a nozzle 70. The furnace body 10 is a structure formed in a substantially rectangular parallelepiped, and as shown in FIG. 1, carry-in inlets 11 and carry-out outlets 12 are provided at both ends in the front-rear direction. As shown in FIGS. 1 and 2, the internal space of the furnace body 10 is separated by the partition wall 50 and the belt 22 of the belt conveyor 20. Of the internal space of the furnace body 10, the space above the partition wall 50 is referred to as space S2. Further, the space below the partition wall 50 in the internal space of the furnace body 10 is further divided into upper and lower parts by the belt 22, and the space between the partition wall 50 and the belt 22 is referred to as a space S1 and is more than the belt 22. The space below is referred to as space S3. Both the carry-in entrance 11 and the carry-out outlet 12 communicate with the space S1. The object to be dried 34 placed on the belt 22 is carried into the space S1 from the carry-in entrance 11, travels in the space S1 in the transport direction, and is carried out from the carry-out port 12.

The infrared heater 40 is a device that irradiates an object to be dried 34 passing through the space S1 with infrared rays, and is installed in the space S2 at least one. In the present embodiment, a plurality of infrared heaters 40 (9 in the present embodiment) are arranged substantially evenly in the space S2 along the transport direction of the object to be dried 34. All of the plurality of infrared heaters 40 have the same configuration, and all of them are attached so that the longitudinal direction is orthogonal to the transport direction. Hereinafter, the configuration of one infrared heater 40 will be described.

As shown in the enlarged views of FIGS. 2 and 4, the infrared heater 40 includes a heater main body 43 formed so that an inner tube 42 (transmission tube) surrounds a filament 41 which is a heating element, and an outer side of the heater main body 43. It is provided with an outer tube 44 (permeation tube) provided in the above and formed so as to surround the inner tube 42. Further, the infrared heater 40 is a space between the inner pipe 42 and the outer pipe 44, and has a refrigerant flow path 46 through which the refrigerant can flow, and a pair of bottomed cylinders airtightly fitted to both left and right ends of the outer pipe 44. It is equipped with a cap 48.

The filament 41 is a heating element that radiates infrared rays when heated, and is made of W (tungsten) in this embodiment. Examples of the material of the filament 41 include Ni—Cr alloys, Mo, Ta, and Fe—Cr—Al alloys. Power is supplied to both ends of the filament 41 from a power supply source (not shown). The inner tube 42 and the outer tube 44 are cylindrical tubes, and are made of an infrared transmitting material that transmits at least a part of infrared rays from the filament 41. In the present embodiment, the material of the inner tube 42 and the outer tube 44 is quartz glass. The inside of the inner pipe 42 has an atmosphere in which a halogen gas is added to an argon gas. In the refrigerant flow path 46, a fluid such as air can flow as a refrigerant. The refrigerant flowing through the refrigerant flow path 46 plays a role of lowering the temperature of the outer pipe 44, which is the outer surface of the infrared heater 40, or adjusting the temperature to an arbitrary temperature. The cap 48 is fixed in the furnace body 10 by a mounting member (not shown), and holds the heater main body 43 and the outer pipe 44. The cap 48 is provided with a wiring outlet (not shown) and a refrigerant inlet / outlet, through which power is supplied from the outside of the furnace body 10 to the filament 41 and between the outside of the furnace body 10 and the refrigerant flow path 46. The inflow and outflow of the refrigerant is possible. The infrared heater 40 can generate infrared rays having various wavelengths. For example, the infrared heater 40 is adapted to generate infrared rays (near infrared rays) having a peak wavelength of about 6 μm or less.

The partition wall 50 is arranged between the upper and lower surfaces of the object to be dried 34 and the plurality of infrared heaters 40, which are conveyed in the internal space of the furnace body 10 in the vertical direction, and separates the space S1 and the space S2 of the furnace body. .. The partition wall 50 includes a transmissive member 51 made of a material that transmits infrared rays (particularly near infrared rays) and a shielding member 52 made of a material that shields (does not transmit) infrared rays (particularly near infrared rays). ing.

As shown in FIGS. 1 to 3, the shielding member 52 extends horizontally in the front-rear direction and has a shape in which the central portion in the left-right direction protrudes upward in a rectangular shape. A plurality of openings are arranged along the front-rear direction on the top surface (upper end surface of the shielding member 52) of the portion of the shielding member 52 that protrudes in a rectangular shape. Each of the plurality of transmission members 51 is arranged on the upper end surface of the shielding member 52 so as to close each of the plurality of openings. In the present embodiment, the shape of the opening of the shielding member 52 and the shape of the transmitting member 51 are rectangular in top view. Further, the transparent member 51 is a plate-shaped member. As shown in FIG. 4, each of the plurality of openings of the shielding member 52 is located directly below the infrared heater 40, and has a one-to-one correspondence with the infrared heater 40.

The area where the infrared rays from the infrared heater 40 are irradiated to the object to be dried 34 is limited by the presence of the shielding member 52. More specifically, among the infrared rays radiated from the filament 41 of the infrared heater 40, the infrared rays transmitted through the openings of the transmitting member 51 and the shielding member 52 reach the object to be dried 34. That is, as shown in FIG. 4, the irradiation angle α of the infrared rays emitted from each of the infrared heaters 40 to the object to be dried 34 is limited to a predetermined value by the shielding member 52. As a result, as shown in FIG. 4, in the space S1, an irradiation section 55 in which the infrared rays emitted from the infrared heater 40 are irradiated to the object to be dried 34 and a non-irradiation section 56 in which the object to be dried 34 is not irradiated are formed. Exists. A plurality of irradiated sections 55 and non-irradiated sections 56 exist, and are arranged alternately along the transport direction of the object to be dried 34.

In the irradiation section 55, the shielding member 52 does not exist on the section where the infrared rays from the filament 41 can reach the object to be dried 34 linearly without being reflected, that is, on the straight line between the filament 41 and the object to be dried 34. Let it be a section. The non-irradiated section 56 is a section in which the infrared rays from the filament 41 are not reflected and cannot reach the object to be dried 34 in a straight line, that is, a section in which a shielding member exists on a straight line between the filament 41 and the object to be dried 34. To do. The two broken lines that define the range of the irradiation angle α shown in the enlarged view of FIG. 4 are tangent lines between the shielding member 52 and the filament 41. As shown in FIG. 4, of the infrared irradiation surface (here, the upper surface) of the object to be dried 34, the region between the two broken lines is the irradiation section 55, and the region between the adjacent irradiation sections 55 is. It becomes the non-irradiation section 56.

The irradiation section 55 is a region determined by the positional relationship between the region where the shielding member 52 does not exist (here, the opening of the shielding member 52) and the infrared heater 40 corresponding to the region. For example, in the present embodiment, since the plurality of openings of the shielding member 52 and the infrared heater 40 have a one-to-one correspondence with each other, one infrared heater 40 is covered through an opening located directly below itself. Only the section where the dried product 34 is irradiated with infrared rays is defined as the irradiation section 55. On the other hand, the infrared rays from one infrared heater 40 can reach the object to be dried 34 through an opening located other than directly under the infrared heater 40, but the infrared rays reach in that way. The section to be used is not included in the irradiation section 55. Infrared rays from the infrared heater 40 reach the object to be dried 34 (linearly without being reflected) through a region other than the region corresponding to the infrared heater 40 in the "region where the shielding member 52 does not exist". ), It is preferable to adjust at least one or more of the positional relationship between the infrared heater 40 and the shielding member 52, the shape of the infrared heater 40, and the shape of the shielding member 52.

In the present embodiment, as shown in FIG. 2, the lower surfaces of the shielding member 52 on both sides in the left-right direction are in contact with both ends of the upper surface of the belt 22. As a result, as described above, the space below the partition wall 50 is divided into the space S1 and the space S3.

Examples of the material of the transmission member 51 include quartz glass. Quartz glass has a property of transmitting infrared rays (near infrared rays) having a wavelength of 3.5 μm or less with high transmittance. Examples of the material of the shielding member 52 include stainless steel and aluminum. Stainless steel is suitable for the shielding member 52 because it has a property of not transmitting infrared rays having a wavelength of about 6 μm or less. Further, the shielding member 52 preferably reflects infrared rays. Aluminum is more suitable for the shielding member 52 because it not only has a property of not transmitting infrared rays having a wavelength of about 6 μm or less and also has a higher infrared reflectance than stainless steel. When the shielding member 52 reflects infrared rays, overheating of the partition wall 50 can be suppressed.

As shown in FIG. 1, a plurality of nozzles 60 are arranged above each infrared heater 40 in the space S2 of the furnace body 10 with a predetermined interval in the front-rear direction. From each nozzle 60, temperature-adjusted air is discharged downward (see the thin arrow). The temperature of the partition wall 50 is adjusted by hitting the partition wall 50 with the air discharged in this way. The air discharged in this way is discharged to the outside through an exhaust port 13 provided on the upper surface of the furnace body 10 (see a thin arrow).

Similarly, an air supply port 14 and an exhaust port 15 are formed in the space S3 of the furnace body 10. The temperature-adjusted air is discharged rearward from the air supply port 14 (see the thin arrow). The temperature of the belt 22 is adjusted by hitting the belt 22 with the air discharged in this way. The air discharged from the air supply port 14 is discharged to the outside through the exhaust port 15 (see the thin arrow).

The nozzle 70 is a nozzle for discharging nitrogen gas (N ₂ gas), and is arranged in the vicinity of the carry-in inlet 11 on the outside of the furnace body 10 as shown in FIG. From the nozzle 70, nitrogen gas whose temperature and humidity have been adjusted is discharged toward the inside of the space S1 in the transport direction (see the thick white arrow). By allowing the nitrogen gas to flow in the space S1 in the transport direction in this way, the temperature and solvent concentration of the gas containing the solvent evaporated from the object to be dried 34 are made as uniform as possible in the region near the surface of the object to be dried 34. It has become. The nitrogen gas that has passed through the space S1 is discharged to the internal space S4 of the furnace body 80, which will be described later, via the carry-out port 12 (see the thick white arrow). The gas discharged from the nozzle 70 is not limited to nitrogen gas and may be an inert gas, for example, argon.

The hot air drying furnace 1b is a device for drying the object to be dried 34 using hot air, and includes a furnace body 80 and a nozzle 85 as shown in FIG. The furnace body 80 is connected to the rear end of the furnace body 10. The inside of the furnace body 80 is composed of one space S4. The carry-out port 12 of the furnace body 10 described above also serves as a carry-in port of the furnace body 80. Further, a carry-out port 81 is provided at the rear end of the furnace body 80. The object to be dried 34, which is placed on the belt 22 and has passed through the carry-out port 12 of the furnace body 10, travels in the space S4 in the transport direction and is carried out from the carry-out port 81.

An air supply port 83 and an exhaust port 84 are formed below the belt 22 in the space S4 of the furnace body 80, similarly to the air supply port 14 and the exhaust port 15 of the furnace body 10. The temperature-adjusted air is discharged rearward from the air supply port 83 (see the thin arrow). The air discharged from the air supply port 83 in this way heats the object to be dried 34 in the space S4 from below and adjusts the temperature. This makes it easier to keep the temperature of the object to be dried 34 constant.

As shown in FIG. 1, a plurality of nozzles 85 are arranged above the furnace body 80 in the space S4 with a predetermined interval in the front-rear direction. Air (hot air) adjusted to a high temperature is discharged downward from each nozzle 85 (see the thin arrow). When the air (hot air) discharged in this way hits the object to be dried 34, the object to be dried 34 is further dried. The air (hot air) discharged in this way is discharged to the outside through an exhaust port 82 provided on the upper surface of the furnace body 80 (see a thin arrow). From the exhaust port 82, the nitrogen gas flowing into the space S4 from the space S1 and the solvent evaporated from the object to be dried 34 are also discharged to the outside.

The belt conveyor 20 (conveying means) is a mechanism for transporting the object to be dried 34 in the transport direction (here, in the front-rear direction), and includes a belt 22 and a plurality of guide rolls 30. The belt 22 is moved in the transport direction by a well-known belt drive mechanism (not shown), and is in the space S1 of the furnace body 10 of the infrared drying furnace 1a and the space S4 of the furnace body 80 of the hot air drying furnace 1b in this order. pass. As the belt 22 moves, the object to be dried 34 on the belt 22 is conveyed in the conveying direction. A plurality of guide rolls 30 are arranged in the space S3 of the furnace body 10 and in the space S4 of the furnace body 80 along the transport direction to guide the moving belt 22. In the present embodiment, the PET film 32 is placed on the upper surface of the belt 22, and the object to be dried 34 is placed on the upper surface of the PET film 32. The PET film 32 is used for the purpose of facilitating the handling of the object to be dried 34 (see FIGS. 2 and 4).

The control device 90 is configured as, for example, a microprocessor centered on a CPU. The control device 90 controls the belt drive mechanism of the belt conveyor 20 to control the moving speed of the belt 22. The control device 90 outputs a control signal to a power supply source (not shown) of the filament 41 to control the heater output (power consumption) of the filament 41, thereby controlling the temperature of the filament 41 and the radiant intensity of infrared rays. The control device 90 controls the temperature and flow rate of each gas discharged from the air supply port 14, the nozzles 60, 70, and 85. The control device 90 also controls the humidity of the nitrogen gas discharged from the nozzle 70. Further, the control device 90 includes a display operation unit such as a touch panel (not shown), and inputs an instruction from the operator or outputs information to the operator.

Next, a state in which the drying device 1 configured in this way dries the object to be dried 34 will be described. The drying apparatus 1 performs a process including a drying step of drying the object to be dried by transporting the object to be dried 34 so as to alternately pass through the irradiated section 55 and the non-irradiated section 56 a plurality of times. The dried product 34 is dried to produce a dried product. First, for example, when a processing start instruction is input from an operator, the control device 90 energizes the filament 41 to radiate infrared rays, and at the same time, the temperature of each gas discharged from the air supply port 14, the nozzles 60, 70, 85. And control the flow rate. As a result, the control device 90 adjusts the space S1 so as to be in a predetermined state. Next, the control device 90 moves the belt 22 at a predetermined speed to start transporting the object to be dried 34. While passing through the space S1 of the infrared drying furnace 1a, the object to be dried 34 is irradiated with infrared rays from the infrared heater 40 in the irradiation section 55, whereby components such as a solvent are evaporated and dried. Further, the object to be dried 34 is further dried by the hot air from the nozzle 85 while passing through the space S4 of the hot air drying furnace 1b. Then, the object to be dried 34 is dried to become a dried body, and is carried out from the carry-out port 81. After that, the dried product is peeled off from the PET film 32 and fired to become a fired product.

In the drying device 1 of the present embodiment described in detail above, due to the presence of the shielding member 52, a plurality of irradiated sections 55 and non-irradiated sections 56 are alternately provided in the space S2 along the transport direction of the object to be dried 34. Existing. Therefore, when the object to be dried 34 is conveyed through the space S1, the object to be dried 34 is dried while alternately passing through the irradiated section 55 and the non-irradiated section 56 a plurality of times. As a result, the drying device 1 can reduce the temperature variation during drying of the object to be dried 34 by infrared rays. The reason for this will be explained. First, when the object to be dried 34 contains a plurality of types of substances, the susceptibility to heating by infrared rays may differ between the plurality of types of substances due to the difference in the absorption rate of infrared rays between the plurality of types of substances. In this case, the temperature in the object to be dried 34 may vary due to the irradiation of infrared rays, for example, the portion of the object to be dried 34 in which many substances that are easily heated are unevenly distributed becomes high in temperature. Therefore, while the object to be dried 34 passes through the irradiation section 55, the temperature in the object to be dried 34 may vary due to the irradiation of infrared rays, and the local temperature difference may widen. However, while the object to be dried 34 passes through the non-irradiated section 56, the object to be dried 34 is less likely to be heated by infrared rays, and the temperature variation in the object to be dried 34 becomes smaller due to heat conduction. Therefore, since the irradiation section 55 and the non-irradiation section 56 are alternately present, for example, as compared with the case where the non-irradiation section 56 does not exist and the infrared rays are continuously irradiated, when the object to be dried 34 is dried. Temperature variation can be reduced. If the temperature of the object to be dried 34 varies, the drying rate varies, which may cause problems such as non-uniform thickness of the object to be dried 34 (dried body) after drying. The drying device 1 of the present embodiment can suppress such a defect of the dried body by reducing the variation in the temperature of the object to be dried 34 at the time of drying. The temperature variation in the object to be dried 34 in the irradiation section 55 can occur in any of the front-rear direction, the left-right direction, and the up-down direction (thickness direction), but the non-irradiation section 56 exists in any direction. By doing so, the variation in temperature can be reduced. Further, if the non-irradiated section 56 does not exist and the infrared rays are continuously irradiated, the temperature of the object to be dried 34 may rise sharply, resulting in overdrying. The drying device 1 of the present embodiment can also suppress such overdrying due to the presence of the non-irradiated section 56.

In the infrared drying furnace 1a, since drying is performed without using hot air, it is possible to prevent the surface of the object to be dried 34 from becoming hotter than the others. Therefore, the variation in temperature in the thickness direction can be further reduced. Further, when the surface of the object to be dried 34 becomes hotter than the others by using hot air, the solvent near the surface may evaporate more and a binder may be deposited near the surface of the object to be dried 34. Then, the precipitated binder and the raw material particles may act like a lid near the surface of the object to be dried 34 to inhibit the evaporation of the solvent. On the other hand, the infrared drying furnace 1a can suppress the precipitation of the binder and suppress the inhibition of the evaporation of the solvent by drying without using hot air. Although hot air is used in the hot air drying furnace 1b, the above problem is caused by the surface of the object to be dried 34 becoming higher than the others because the object to be dried 34 is sufficiently dried in the infrared drying furnace 1a. Is unlikely to occur.

Further, the drying device 1 includes a partition wall 50 arranged between the object to be dried 34 carried in the internal space of the furnace body 10 and the plurality of infrared heaters 40. The shielding member 52 constitutes a part of the partition wall 50. Further, the partition wall 50 has a transmission member 51 which is arranged so as to close a portion where the shielding member 52 does not exist, that is, an opening, and allows infrared rays to be transmitted to the irradiation section 55 by transmitting infrared rays from the infrared heater 40. ing. Further, the partition wall 50 partitions the internal space of the furnace body 10, and the transmission member 51 partitions the internal space of the furnace body 10. As a result, the shielding member 52 can also be used as a part of the partition wall 50.

It is needless to say that the present invention is not limited to the above-described embodiment, and can be implemented in various aspects as long as it belongs to the technical scope of the present invention.

For example, in the above-described embodiment, the shielding member 52 is also used as a part of the partition wall 50, but the present invention is not limited to this. If the shielding member 52 can shield the infrared rays from the infrared heater 40 so that the irradiation section 55 and the non-irradiation section 56 alternately exist in the internal space of the furnace body 10 along the transport direction of the object to be dried 34, respectively. It may be arranged in any way. For example, the drying device 1 may have a partition wall and a shielding member separately, or the drying device 1 may have a partition wall and a shielding member. The drying device 1 may include, in addition to or in place of the shielding member 52, a shielding member arranged for each of the infrared heaters 40. FIG. 5 is an explanatory view of the infrared heater 140 provided with the shielding member 152 of the modified example. The infrared heater 140 includes a shielding member 152 arranged so as to cover only a part of the periphery of the filament 41. The shielding member 152 is arranged on the outer surface of the infrared heater 140 (here, the outer surface of the outer tube 44). The infrared rays from the filament 41 of the infrared heater 140 are partially shielded by the presence of the shielding member 152, and the irradiation angle α of the infrared rays irradiated to the object to be dried 34 is limited to a predetermined value. Even when each of the plurality of infrared heaters 140 included in the drying device 1 has the shielding member 152, the irradiation section 55 and the non-irradiation section 56 can be alternately present as in the above-described embodiment. The same effect as that of the above-described embodiment can be obtained. The shielding member 152 may be a member that is adhered to the outer surface of the outer tube 44 and is independent of the outer tube 44, or a film forming method such as coating, sputtering, CVD, or thermal spraying may be applied to the surface of the outer tube 44. It may be a shielding layer formed by using. For example, the shielding member 152 may be formed by coating the outer surface of the outer tube 44 with gold or aluminum.

Further, in addition to or in place of the shielding member 152, the shielding member is arranged at a position away from the outer surface of the infrared heater 240 (here, the outer surface of the outer tube 44) as in the shielding member 252 of the modified example of FIG. You may. Even when each of the plurality of infrared heaters 240 included in the drying device 1 has the shielding member 252, the irradiation section 55 and the non-irradiation section 56 can be alternately present as in the above-described embodiment. The same effect as that of the above-described embodiment can be obtained. However, since it is easy to miniaturize the entire infrared heater 240 including the shielding member, it is preferable to dispose the shielding member 152 on the surface of the outer tube 44 as shown in FIG. 5 without disposing the shielding member 252.

The shielding members 152 and 252 preferably reflect infrared rays in the same manner as the shielding members 52. In this way, the infrared rays reflected by the shielding member are easily used for at least one of the heating of the filament 41 and the heating of the object to be dried 34, so that the energy efficiency is improved. For example, if the shape of the cross section (cross section shown in FIGS. 5 and 6) of the inner peripheral surfaces of the shielding members 152 and 252 is arcuate and the filament 41 is located at the center of the circle including the arc, the shielding member 152, The infrared rays reflected by the 252 can be efficiently used for heating the filament 41. Further, for example, if the shape of the cross section (cross section shown in FIG. 6) of the inner peripheral surface of the shielding member 252 is parabolic and the filament 41 is located at the focal point thereof, the infrared rays reflected by the shielding member 252 are dried. It can be efficiently used for heating the object 34.

In the above-described embodiment, if the space S1 and the space S2 do not have to be completely separated, the transmission member 51 may be omitted. Even in this way, similarly to the above-described embodiment, a plurality of irradiation sections 55 and non-irradiation sections 56 can be alternately present.

In the above-described embodiment, the filament 41 of the infrared heater 40 is a linear heating element, but the present invention is not particularly limited to this. For example, the drying device 1 may include an infrared heater having a planar heating element.

In the above-described embodiment, the drying device 1 is provided with a plurality of infrared heaters 40, but it may be provided with one or more infrared heaters 40. For example, even when the drying device 1 has only one infrared heater 40, if there are a plurality of openings of the shielding member 52 corresponding to the infrared heater 40, a plurality of irradiation sections 55 and a plurality of non-irradiation sections 56 are alternately present. Can be done.

In the above-described embodiment, the infrared heater 40 is arranged inside the furnace body 10, but the present invention is not particularly limited to this. For example, the infrared heater 40 may be arranged outside the furnace body 10. In this case, a part of the furnace body 10 may be made of an infrared transmitting material so that the infrared rays from the infrared heater 40 can reach the inside of the furnace body 10. Further, when the infrared heater 40 is arranged outside the furnace body 10, the partition wall 50 does not have to be an internal partition wall that partitions the internal space of the furnace body 10, and the object to be dried that is conveyed in the internal space of the furnace body 10. The partition wall 50 may be arranged between the 34 and the infrared heater 40. For example, the infrared heater 40 may be arranged above the outside of the furnace body 10, and the ceiling portion of the furnace body 10 may be composed of a transmission member 51 and a shielding member 52 as in the partition wall 50. That is, the shielding member and the transmission member may also be used as a part of the furnace body 10. In this case, the ceiling portion of the furnace body 10 corresponds to "a partition wall arranged between the object to be dried carried in the internal space of the furnace body and the one or more infrared heaters".

In the above-described embodiment, each of the plurality of transmission members 51 is arranged so as to close each of the plurality of openings of the shielding member 52, but the present invention is not limited to this. For example, one transmission member 51 may be arranged so as to cover the entire upper end surface of the shielding member 52, and one transmission member 51 may close a plurality of openings.

In the above-described embodiment, the space below the partition wall 50 is divided into the space S1 and the space S3 by the belt 22, but the space S1 and the space S3 may communicate with each other.

In the above-described embodiment, even if the shielding member 52 has a vertically extending vertical portion provided around the opening so as to prevent the passage of infrared rays from other than the infrared heater 40 corresponding to the opening. Good. FIG. 7 is an explanatory view of the shielding member 352 of the modified example. As shown in FIG. 7, the shielding member 352 is arranged around the main body portion 352a similar to the shielding member 52 shown in FIG. 4 and the opening of the main body portion 352a, and is an upright portion extending upward from the main body portion 352a. 352b and. The upright portion 352b is a flat plate-shaped member, and is arranged one by one before and after each of the openings of the main body portion 352a. The upright portion 352b is made of the same material as the main body portion 352b, for example. The standing portion 352b is located so as not to hinder the arrival of infrared rays from the infrared heater 40 to the opening corresponding to the infrared heater 40 (the opening directly below the infrared heater 40 in FIG. 7) and the irradiation section 55. .. On the other hand, the vertical length of the upright portion 352b is appropriately adjusted so that the infrared heater 40 other than the infrared heater 40 corresponding to the opening of the main body portion 352a (other than directly above the opening in FIG. 7). Infrared rays from the infrared heater 40) located in the above are not reflected and cannot reach the opening linearly.

1 Drying device, 1a Infrared drying furnace, 1b Hot air drying furnace, 10 Furnace, 11 Carry-in inlet, 12 Carry-out port, 13 Exhaust port, 14 Air supply port, 15 Exhaust port, 20 Belt conveyor, 22 Belt, 30 Guide roll, 32 PET film, 34 to be dried, 40, 140, 240 infrared heater, 41 filament, 42 inner tube, 43 heater body, 44 outer tube, 46 refrigerant flow path, 48 cap, 50 partition wall, 51 transmission member, 52, 152 , 252,352 Shielding member, 55 irradiation section, 56 non-irradiation section, 60 nozzles, 70 nozzles, 80 furnace body, 81 carry-out port, 82 exhaust port, 83 air supply port, 84 exhaust port, 85 nozzle, 90 control device, 352a main body, 352b standing, S1-S4 space.

Claims (6)

A drying device that dries an object to be dried containing raw material particles, a binder, and a solvent.
With the furnace body
A transport means for transporting the object to be dried in the transport direction in the internal space of the furnace body, and
When heated has a heating element that emits infrared, 1 and more infrared heaters that can emit infrared radiation from the heat generating body material to be dried that is conveyed to the interior space of the furnace body,
In the interior space of the furnace body, so that the irradiation morphism sections and non-irradiated sections are each plurality of alternately along the conveying direction, a shield member for shielding the infrared rays from the infrared heater,
Equipped with a,
The irradiation section is determined by the positional relationship between the region where the shielding member does not exist and the infrared heater corresponding to the region, and the shielding member and the heating element are two in a cross-sectional view along the transport direction. It is a region within the range of the irradiation angle α with the angle formed by the tangent of the infrared ray as the irradiation angle α, and is a section in which the shielding member does not exist on the straight line between the heating element and the object to be dried.
The non-irradiation section is a region outside the range of the irradiation angle α, which exists because the shielding member is arranged so as to limit the irradiation angle α, and is an irradiation section adjacent to the transport direction. It is a region between the heating elements and a section in which the shielding member exists on a straight line between the heating element and the object to be dried.
Drying device. The drying apparatus according to claim 1.
A partition wall arranged between the object to be dried carried in the internal space of the furnace body and the one or more infrared heaters.
With
The shielding member constitutes a part of the partition wall.
The partition wall is arranged so as to close a portion where the shielding member does not exist, and has a transmissive member that transmits infrared rays from the infrared heater and allows the irradiation section to be irradiated with infrared rays.
Drying device. A plurality of the infrared heaters are arranged along the transport direction.
The shielding member is arranged so as to cover only a part of the periphery of each of the plurality of infrared heaters.
The drying apparatus according to claim 1. The infrared heater has a permeation tube, which transmits infrared rays from the heating element surrounds the periphery of the heating element,
The shielding member is arranged on the surface of the transmission tube.
The drying apparatus according to claim 3. The shielding member reflects infrared rays.
The drying apparatus according to claim 3 or 4. By conveying the material to be dried comprising the raw material particles and a binder and a solvent, to pass through a plurality of times each alternating with irradiation elevation section and a non-irradiation region, a drying step of drying the該被dried product,
Only including,
The irradiation section is a section in which a local temperature difference in the object to be dried is widened by irradiation with infrared rays as the object to be dried is transported.
In the non-irradiated section, infrared rays are not irradiated to the object to be dried as compared with the irradiated section, so that the local temperature difference in the object to be dried becomes smaller as the object to be dried is transported. Is,
How to make a dried product.

Images