JP2694325B2 - Floating device for sheet material - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet material made of plastic film, woven glass fiber, metal foil, paper or the like while being conveyed in a non-contact floating state. The present invention relates to an improvement of a levitating device for a sheet material, which heats or cures the material without damaging the material such as scratches. [0002] Conventionally, as an example of a levitating device for a sheet material, Japanese Patent Publication Nos. 54-38525 and 53-466.
The device described in No. 6 is known. That is, in the conventional apparatus, as shown in FIG. 6, a plurality of nozzle boxes 1, 1 ... Extending along the transverse direction of the sheet feeding / conducting path D are arranged in a staggered manner on the upper and lower sides of the sheet feeding / conducting path D. Configured. Each nozzle box 1 has a gas guide plate 2 which is long in the left and right direction, and a pair of front and rear gas ejection slits 3 and 3 which are provided in the front and rear outer edges of the gas guide plate 2 and which are long in the left and right direction (for example, slit gap W ₁ = 1 to 3 m).
m). The gas guide plate 2 includes a flat static pressure holding portion 2a, a pair of front and rear Coanda portions 2c and 2c curved at the front and rear edges of the static pressure holding portion 2a, and a pair of front and rear hem portions hanging from the Coanda portions 2c and 2c. 2b and 2b are formed. The gas jetting slits 3, 3 are opened so that the outer surfaces of the skirts 2b, 2b serve as gas guide surfaces. The gas having a wind velocity V ₁ (for example, V ₁ = 5 to 70 m / sec) ejected from the gas ejection slits 3 and 3 is guided by the skirts 2b and 2b, and the Coanda portions 2c and 2c.
And the direction is changed to the static pressure holding portion by the Coanda effect in the Coanda portions 2c and 2c, and the static pressure holding portion 2a is sprayed onto the sheet material E while being separated from the static pressure holding portion 2a. The sheet material E is held and floated so as to draw a wave curve by the cushioning action of the static pressure generated in the static pressure holding portion 2a of each nozzle box 1. When the coating liquid applied to the sheet material E or the sheet material E itself is dried or heat-treated by the sheet material levitation device, the nozzle boxes 1, 1, ...
The gas jetted from the gas jetting slits 3 and 3 is heated to a desired temperature, and the sheet material is heated by convection heat transfer of the heating gas. In order to increase the heating capacity by this convective heat transfer, the jetting speed of the heating gas is increased to increase the film heat transfer coefficient, and the temperature of the heating gas is increased. However, the temperature of the sheet material E heated by the convective heat transfer reaches the inside of the sheet material due to the heat transfer resistance of the sheet material E and the coating liquid, so that the surface of the sheet material in contact with the heating gas becomes the highest. It becomes a low temperature. Therefore, when the heating capacity due to the convective heat transfer is unduly increased,
Only the surface of the sheet material rapidly heats up, which causes deterioration of the surface of the sheet material and the coating liquid, or causes undesired migration as a dry state. Therefore, in the conventional levitating apparatus for sheet material, there is a limit to the drying or heat treatment of the sheet material, and there is a problem that it cannot cope with the high-speed processing of the sheet material. It is an object of the present invention to provide a sheet material levitation device capable of coping with high-speed processing of the sheet material and facilitating the initial passage of the sheet material to the sheet feeding passage. According to a first aspect of the present invention, there is provided a plurality of gas jets extending along a transverse direction of a sheet feed passage at a position facing the sheet feed passage. In a sheet material levitation device in which a nozzle box is appropriately arranged in a pitch along the sheet feeding direction, an infrared radiator facing the sheet feeding conduction path in a non-contact state is arranged between adjacent nozzle boxes. The sheet is characterized in that the infrared radiator is arranged so as to be rotatable between a radiating position where the radiating surface faces the sheet feeding passage and a standby position where the non-radiating surface faces the sheet feeding passage. It is a flotation device for timber. According to a second aspect of the present invention, a plurality of gas ejection nozzle boxes extending in the transverse direction of the sheet feeding passage are provided at positions facing the sheet feeding passage in the sheet feeding direction. In a sheet material levitation device appropriately arranged along a pitch, an infrared radiator facing the sheet feeding conducting path in a non-contact state is arranged between adjacent nozzle boxes, and the infrared radiator is the sheet feeding conducting path. The levitation device for a sheet material, which is arranged so as to be able to move forward and backward so that the radiant surface can freely move toward and away from the radiating surface. According to the present invention as set forth in claims 1 and 2, since the infrared radiator facing the sheet feeding conduction path in a non-contact state is arranged between the adjacent nozzle boxes, the sheet feeding guide is provided. Infrared rays emitted from the infrared radiator are emitted to the sheet material while maintaining the floating state of the sheet material passing through the passage. The radiated infrared rays can penetrate the sheet material and heat the sheet material from the inside thereof, and can improve the drying or heat treatment without deteriorating the surface of the sheet material and the coating liquid. According to the first aspect of the present invention, when the sheet material is initially passed through the sheet feeding / conducting path, if the infrared radiator is set to the standby position, the sheet material is not irradiated with infrared rays, so that the sheet material is not heated. The sheet material can be smoothly passed through the initial stage without giving a target damage. After the initial passage of the sheet material, the infrared radiation emitted from the radiation surface can be applied to the sheet material by rotationally moving the radiation surface of the infrared radiator to the radiation position. According to the second aspect of the present invention, when the sheet material is initially passed through the sheet feeding / conducting path, if the radiation surface of the infrared radiator is separated from the sheet feeding / conducting path, the heating force for the sheet material is increased. Since it can be reduced, the sheet material can be smoothly passed through the initial stage without giving thermal damage to the sheet material. The heating force on the sheet material can be increased by bringing the emitting surface of the infrared radiator closer to the sheet feeding path after the initial passage of the sheet material. A sheet material levitation device according to the present invention will be described with reference to an embodiment shown in the drawings. In the following description, “front” means the right side of each of FIGS. 2, 3 and 5, and “rear” means the left side of these figures. "left"
Means the left side in FIG. 4, and “right” means the right side in this figure. (First Embodiment) FIGS. 1 and 2 show a first embodiment of the present invention. In the present embodiment, a plurality of nozzle boxes 1, 1 ... Extending in the transverse direction of the sheet feeding passage D are arranged in a staggered manner on the upper and lower sides of the sheet feeding passage D in the conventional sheet material shown in FIG. It is the same as the levitating device. The main improvement in this embodiment is that an infrared radiator 5 facing the sheet feeding conduction path D in a non-contact state is arranged between the nozzle boxes 1 and 1 adjacent to each other in the front and rear, and the infrared radiator 5 has a radiation surface 5b. It is arranged such that it can be rotated between a radiation position facing the sheet feeding path D and a standby position facing the non-radiating surface 5d to the sheet feeding path D. The infrared radiator 5 is, as shown in FIG.
An infrared ray (including a far infrared ray) having an appropriate wavelength is emitted from the emission surface 5b facing the sheet feeding / conducting path D.
An appropriate number of heating tubes 7 are provided inside the casing 5a. As the heat generating pipe 7, a heat medium circulating pipe or a pipe with a built-in electric heater that allows heat medium oil or steam to pass therethrough is appropriately selected. The radiation surface 5b of the infrared radiator 5 is optionally coated with a ceramic material made of a mixture of alumina, magnesia, zirconia, titania and the like. This ceramic material has a high emissivity ε (for example, ε =
0.5-0.9), and the sheet material E and / or the sheet material E
The wavelength of heat rays with high absorptivity of the coating liquid applied to (for example,
(3 to 10 μm when the coating liquid is an organic polymer or water)
Those that radiate are selected appropriately. The infrared radiator 5 is
The outer surface other than the radiation surface 5b is covered with a heat insulating coating layer 5c. The infrared radiator 5 is, as shown in FIG.
It is a non-radiative surface which is rotatably supported by the side frames 8 and 8 extending to the left and right sides via brackets 9 and 9 and which is covered with a radiation surface 5b or a heat insulation layer by the operation of the rotation means 10. The rear surface 5d can be selected to face the sheet feeding conduction path D. The face-to-face selection can be made to prevent the sheet material E from receiving high-temperature infrared rays when the sheet material E is initially passed through the sheet feeding conduction path D. This is because the passage speed of the sheet material E during the initial passage is slow, and therefore when the sheet material E is irradiated with high-temperature infrared rays, the sheet material E
Is cut by receiving a thermal mage. The rotating means 10 is, for example, a pinion 12 fitted on each pivot 11 and each pinion 12.
It is composed of a rack 13 that meshes with each other, and an operating portion (not shown) including an air cylinder for sliding the rack 13 back and forth. Each of the pivots 11 is a hollow shaft so that heat medium piping or electric wiring can be formed, and heat generation of the infrared radiator 5 is performed through a joint 16 composed of a rotary joint or a slip ring attached to the shaft end. The pipe 7 and the external pipe 20 (or external wiring) are connected. In the nozzle box 1, at least the static pressure holding portion 2a of the gas guide plate 2 is optionally covered with a radiation promoting coating layer 14 made of the same ceramic material as described above. The nozzle box 1 is joined to the side frames 8 and 8 via a bracket 15 and is joined to gas supply ducts 17 and 17 extending in the front and rear so as to be able to receive gas. A recirculation gas passage 6 is formed between the nozzle box 1 and the infrared radiator 5. The cross-sectional area of the recirculation gas passage 6 is such that the wind velocity V _{2 of the} recirculation gas flowing in the passage 6 in the left-right direction or the up-down direction is 1/20 to 20 times the gas wind velocity V ₁ ejected from the gas ejection slit 3 of the nozzle box 1.
It is determined to be 1/2 (generally 1/10 to 1/5). The recirculation gas passage 6 has spaces 18, 18 formed between the side frame 8 and the gas supply duct 17, and a space 1 formed between the gas supply ducts 17, 17.
9 is communicated with the recirculation gas passage 6 as necessary, and is configured to discharge the recirculation gas flowing through the recirculation gas passage 6 as much as possible. In this embodiment, since the infrared radiator 5 facing the sheet feeding conduction path D in a non-contact state is arranged between the adjacent nozzle boxes 1 and 1, the sheet feeding conduction path D is arranged. The sheet material E is irradiated with infrared rays emitted from the infrared radiator 5 while maintaining the levitating state of the sheet material E passing through the sheet material E. The radiated infrared rays penetrate into the sheet material E and can heat the sheet material E from the inside thereof.
Drying or heat treatment can be improved without deteriorating the surface and the coating liquid. Further, in the present embodiment, when the sheet material E is initially passed through the sheet feeding passage D, if the radiation surfaces 5b, 5b ... Of the infrared radiators 5, 5 ... Since the sheet material E is not irradiated with infrared rays, the sheet material E can be smoothly passed through initially without giving thermal damage to the sheet material E passing at a low speed. If the infrared radiators 5, 5 ... Are rotated to radiate the radiation surface 5b immediately before or after the initial passage is completed and the main operating state is entered, the sheet material E is irradiated with the radiation surface 5 of the infrared radiators 5, 5 ,.
High-temperature infrared rays emitted from b, 5b ... By the way, the infrared radiator 5 cannot immediately raise the temperature to the high temperature required to radiate infrared rays from the radiation surface 5b due to the relationship with the thermal capacity of the infrared radiator 5. However, in the present embodiment, even in the standby position where the non-radiative surface 5d faces the sheet feeding / conducting path D, it is possible to radiate infrared rays of a predetermined wavelength, and thus the main operation is immediately performed. Can correspond to. (Second Embodiment) FIGS. 3 and 4 show a second embodiment of the present invention. The second embodiment is the first
A major difference from the embodiment is that the infrared radiator 25 is arranged so as to be able to move forward and backward so that it can freely move toward and away from the sheet feeding conduction path D. The infrared radiator 25 arranged between the nozzle boxes 1 and 1 emits infrared rays from the radiation surface 25b toward the sheet feeding / conducting path D by passing a heating gas inside thereof. A reflux gas passage 6 similar to that of the first embodiment is formed between the infrared radiator 25 and the nozzle box 1. The infrared radiator 25 is a casing 25.
A gas passage 27 extending in the left-right direction is formed inside a. An inlet 27a of the gas passage 27 is joined to a heating gas supply duct 28, and an outlet 27b of the gas passage 27 is connected to a heating gas discharge duct 29. Heating gas supply duct 28 and heating gas discharge duct 2
9 are arranged side by side outside the gas supply ducts 17, 17 and are respectively connected to the supply / discharge ports of a heating gas supply / discharge device (not shown). The temperature of the gas passing through the gas passage 27 of the infrared radiator 25 depends on the radiation surface 25b of the infrared radiator 25.
Therefore, the temperature is a temperature at which infrared rays of a desired wavelength can be radiated, and it is generally set appropriately within the range of 200 to 1.000 ° C., though it varies depending on the material of the radiation surface 25b. The outer surface of the infrared radiator 25 excluding the radiation surface 25b,
Heating gas supply duct 28 and heating gas discharge duct 29
Are optionally covered with heat insulating layers 25c, 28c, 29c. The radiation surface 25b of the infrared radiator 25 is optionally coated with a ceramic material composed of a simple substance or a mixture of alumina, magnesia, zirconia, titania, etc., as in the first embodiment. The side frames 8 and 8 for supporting and fixing the infrared radiators 25 and 25 and the nozzle boxes 1 and 1 are suspended by wires 22 and 23 so that they can be lifted and lowered. When the material E is initially passed, the infrared radiators 25, 25 ... Are separated from the sheet feeding conduction path D so that the amount of infrared rays received by the sheet E can be reduced. In addition, the infrared radiator 25,
25. and the nozzle boxes 1, 1 ... are not limited to those that can be simultaneously moved up and down, and although not shown in the drawing, they can be independently moved up and down, and the nozzle boxes 1, 1 are attached to the sheet feeding conduction path D. It is of course possible to bring the infrared radiators 25, 25 ... Close to the sheet feeding / conducting path D after the sheets E are brought close to each other and the sheet E is stably levitated. In the present embodiment, since the infrared radiator 25 facing the sheet feeding conduction path D in a non-contact state is arranged between the adjacent nozzle boxes 1 and 1, the sheet feeding conduction path D is arranged. While maintaining the floating state of the sheet material E passing through
Infrared rays emitted from the infrared ray radiator 25 are emitted to the sheet material E. The radiated infrared rays can penetrate into the sheet material E and heat the sheet material E from the inside thereof, and the drying or heat treatment can be improved without deteriorating the surface of the sheet material E and the coating liquid. Further, in the present embodiment, when the sheet material E is initially passed through the sheet feeding / conducting path D, if the infrared radiators 25, 25 ... Since the heating power of infrared rays received by E can be reduced, the sheet material E can be smoothly passed through initially without giving thermal damage to the sheet material E passing at a low speed. If the infrared radiators 25, 25, ... Are brought close to the sheet feeding / conducting path D immediately before or immediately after the initial passage is completed and the main operation state is entered, the sheet material E is the infrared radiator 2
Infrared rays having a strong heating power emitted from the radiation surfaces 25b, 25b of the light emitting elements 5, 25 ... (Third Embodiment) FIG. 5 shows a third embodiment of the present invention. The third embodiment is greatly different from the first embodiment in that the nozzle boxes 31, 31, ... Are arranged on one of the sides (upper side in the drawing) facing the sheet feeding conduction path D and the adjacent nozzles are arranged. The infrared radiator 5 is arranged between the boxes 31 and 31. The infrared radiator 5 can be rotated and moved as in the first embodiment. The nozzle box 31 includes a gas guide plate 32 in which the outer surface of a substrate portion 32d which is long in the left-right direction (FIG. 5 is a right-side sectional view) is covered with a ceramic layer 32e as necessary, and The front side plate 34 continuously extending from the front end bent portion 32f is connected to the front side plate 35 and the rear side plate 35 which forms the gas ejection slit 33 which is long in the left-right direction at the front outer edge of the gas guide plate 32. It is composed of a bottom plate 38 and end plates 37, 37 that cover both left and right ends. The nozzle box 31 may optionally include a wing 39 of a perforated plate extending forward from the front end bent portion 32f of the gas guide plate 32. Conversely, when the wing 39 is provided, the front end bent portion 32f may be provided. Is curved (not shown). The gas guide plate 32 has a static pressure holding portion 32a having a front-rear length L ₁ , a Coanda portion 32c curved at a bending radius R ₂ at a front edge portion of the static pressure holding portion 32a, and a Coanda portion 3
A skirt portion 32b hanging from 2c is formed. The gas jetting slit 33 is provided with a gap W ₃ so that the outer surface of the skirt 32b serves as a gas guide surface. In the nozzle box 31, the gas of the desired temperature ejected from the gas ejection slit 33 while being guided by the skirt portion 32b is the Coanda portion 32c.
Then, after the direction is changed to the static pressure holding portion 32a by the Coanda effect, the static pressure holding portion 32a passes between the static pressure holding portion 32a and the sheet material E, and a negative static pressure is generated in the static pressure holding portion 32a. The sheet material E is held by the suction static pressure action of the negative static pressure generated in the static pressure holding portion 32a of each nozzle box 31. The gas that has passed through the static pressure holding portion 32a of each nozzle box 31 reaches the wing 39, and then a part of the gas passes through the hole 3 of the wing 39.
While passing through 9a, 39a ..., The remaining part passes through the tip 39b of the wing 39 and is guided to a recirculation gas passage 36 described later. Between the front side plate 34 of the nozzle box 31 and the infrared radiator 5, a reflux gas passage 36 extending in the left-right direction is provided.
Are formed. The cross-sectional area of the recirculation gas passage 36 is such that the wind velocity V _{2 of the} recirculation gas flowing in the passage 36 in the left-right direction or the up-down direction is such that the gas ejection slits 33 of the nozzle box 31.
It is determined to be 1/20 to 1/2 (generally 1/10 to 1/5) of the gas wind velocity V ₁ ejected from. An auxiliary recirculation gas passage 39 extending in the left-right direction is formed between the rear plate 35 of the nozzle box 31 and the infrared radiator 5 as needed. (Other Embodiments) In the first embodiment, the infrared radiator 5 is designed so that the sheet material E being initially passed can be rotationally moved so as not to receive infrared rays, but it is not limited to this. Although not shown in the drawings, the infrared radiator 5 is movably arranged from the radiating position facing the sheet feeding conduction path D to the outer standby position not facing the left or right sheet feeding conduction path D. It is also possible to do so. Further, the nozzle boxes 1, 1 ... (Or 31, 31)
The gas to be ejected from (..) may be made an inert gas atmosphere by making the sheet feeding conduction path D an inert gas atmosphere. As described in detail above, the levitating apparatus for sheet material according to the present invention has the following excellent effects. According to the first and second aspects of the present invention, since the heating capacity for the sheet material can be increased by radiant heating by infrared rays, rapid temperature rise of the sheet material surface due to convective heat transfer of gas ejected from the nozzle box is suppressed. It becomes possible. As a result, the present invention can cope with high-speed processing without deteriorating the sheet material and the coating liquid. According to the present invention described in claim 1, the radiation surface of the infrared radiator is rotationally moved between the standby position and the radiation position, so that the sheet material that is initially passing at a low speed can be smoothly moved without giving thermal damage. It can be passed initially,
It is possible to immediately respond to the main operation. As a result, the present invention can dramatically improve the yield of sheet materials and the operating efficiency of the apparatus. According to the second aspect of the present invention, the infrared radiator is moved away from or close to the sheet feeding / conducting path so that the sheet material that is initially passing at a low speed can be smoothly passed through initially without causing thermal damage. At the same time, it is possible to immediately respond to the main operation. As a result, the present invention can dramatically improve the yield of sheet materials and the operating efficiency of the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a first embodiment according to the present invention. FIG. 2 is an enlarged right side sectional view of a main part of the embodiment. 3 is an enlarged main part of a second embodiment according to the present invention, which is a right side sectional view taken along the line III-III in FIG. FIG. 4 is a front sectional view of the embodiment. FIG. 5 is an enlarged right side sectional view of a main part of a third embodiment according to the present invention. FIG. 6 is a perspective view showing a conventional levitating apparatus for a sheet material. [Explanation of Codes] 1 (31) ... Nozzle box 5 (25) ... Infrared radiator D ... Sheet feeding conduction path

Claims (1)

(57) [Claims] For the sheet material, a plurality of gas ejection nozzle boxes extending along the transverse direction of the sheet feeding conduction path are provided at the positions facing the sheet feeding conduction path. In the levitation device, an infrared radiator facing the sheet feeding / conducting path in a contactless manner is arranged between the adjacent nozzle boxes, and the infrared radiator has a radiation position and a non-radiating surface facing the sheet feeding / conducting path. A floatation device for a sheet material, which is arranged so as to be able to rotate between a standby position for facing the sheet feeding conduction path. 2. For the sheet material, a plurality of gas ejection nozzle boxes extending along the transverse direction of the sheet feeding conduction path are provided at the positions facing the sheet feeding conduction path. In the levitation device, an infrared radiator facing the sheet feeding passage in a contactless manner is arranged between the adjacent nozzle boxes, and the infrared radiator allows the radiation surface to freely move toward and away from the sheet feeding passage. A levitating device for a sheet material, which is arranged so that it can move back and forth.